4 perl5db.pl - the perl debugger
8 perl -d your_Perl_script
12 C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when
13 you invoke a script with C<perl -d>. This documentation tries to outline the
14 structure and services provided by C<perl5db.pl>, and to describe how you
19 The debugger can look pretty forbidding to many Perl programmers. There are
20 a number of reasons for this, many stemming out of the debugger's history.
22 When the debugger was first written, Perl didn't have a lot of its nicer
23 features - no references, no lexical variables, no closures, no object-oriented
24 programming. So a lot of the things one would normally have done using such
25 features was done using global variables, globs and the C<local()> operator
28 Some of these have survived into the current debugger; a few of the more
29 interesting and still-useful idioms are noted in this section, along with notes
30 on the comments themselves.
32 =head2 Why not use more lexicals?
34 Experienced Perl programmers will note that the debugger code tends to use
35 mostly package globals rather than lexically-scoped variables. This is done
36 to allow a significant amount of control of the debugger from outside the
39 Unfortunately, though the variables are accessible, they're not well
40 documented, so it's generally been a decision that hasn't made a lot of
41 difference to most users. Where appropriate, comments have been added to
42 make variables more accessible and usable, with the understanding that these
43 I<are> debugger internals, and are therefore subject to change. Future
44 development should probably attempt to replace the globals with a well-defined
45 API, but for now, the variables are what we've got.
47 =head2 Automated variable stacking via C<local()>
49 As you may recall from reading C<perlfunc>, the C<local()> operator makes a
50 temporary copy of a variable in the current scope. When the scope ends, the
51 old copy is restored. This is often used in the debugger to handle the
52 automatic stacking of variables during recursive calls:
57 # Do some stuff, then ...
61 What happens is that on entry to the subroutine, C<$some_global> is localized,
62 then altered. When the subroutine returns, Perl automatically undoes the
63 localization, restoring the previous value. Voila, automatic stack management.
65 The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>,
66 which lets the debugger get control inside of C<eval>'ed code. The debugger
67 localizes a saved copy of C<$@> inside the subroutine, which allows it to
68 keep C<$@> safe until it C<DB::eval> returns, at which point the previous
69 value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep
70 track of C<$@> inside C<eval>s which C<eval> other C<eval's>.
72 In any case, watch for this pattern. It occurs fairly often.
76 This is used to cleverly reverse the sense of a logical test depending on
77 the value of an auxiliary variable. For instance, the debugger's C<S>
78 (search for subroutines by pattern) allows you to negate the pattern
81 # Find all non-'foo' subs:
84 Boolean algebra states that the truth table for XOR looks like this:
90 (! not present and no match) --> false, don't print
94 (! not present and matches) --> true, print
98 (! present and no match) --> true, print
102 (! present and matches) --> false, don't print
106 As you can see, the first pair applies when C<!> isn't supplied, and
107 the second pair applies when it is. The XOR simply allows us to
108 compact a more complicated if-then-elseif-else into a more elegant
109 (but perhaps overly clever) single test. After all, it needed this
112 =head2 FLAGS, FLAGS, FLAGS
114 There is a certain C programming legacy in the debugger. Some variables,
115 such as C<$single>, C<$trace>, and C<$frame>, have I<magical> values composed
116 of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces
117 of state to be stored independently in a single scalar.
123 is checking to see if the appropriate bit is on. Since each bit can be
124 "addressed" independently in this way, C<$scalar> is acting sort of like
125 an array of bits. Obviously, since the contents of C<$scalar> are just a
126 bit-pattern, we can save and restore it easily (it will just look like
129 The problem, is of course, that this tends to leave magic numbers scattered
130 all over your program whenever a bit is set, cleared, or checked. So why do
137 First, doing an arithmetical or bitwise operation on a scalar is
138 just about the fastest thing you can do in Perl: C<use constant> actually
139 creates a subroutine call, and array and hash lookups are much slower. Is
140 this over-optimization at the expense of readability? Possibly, but the
141 debugger accesses these variables a I<lot>. Any rewrite of the code will
142 probably have to benchmark alternate implementations and see which is the
143 best balance of readability and speed, and then document how it actually
148 Second, it's very easy to serialize a scalar number. This is done in
149 the restart code; the debugger state variables are saved in C<%ENV> and then
150 restored when the debugger is restarted. Having them be just numbers makes
155 Third, some of these variables are being shared with the Perl core
156 smack in the middle of the interpreter's execution loop. It's much faster for
157 a C program (like the interpreter) to check a bit in a scalar than to access
158 several different variables (or a Perl array).
162 =head2 What are those C<XXX> comments for?
164 Any comment containing C<XXX> means that the comment is either somewhat
165 speculative - it's not exactly clear what a given variable or chunk of
166 code is doing, or that it is incomplete - the basics may be clear, but the
167 subtleties are not completely documented.
169 Send in a patch if you can clear up, fill out, or clarify an C<XXX>.
171 =head1 DATA STRUCTURES MAINTAINED BY CORE
173 There are a number of special data structures provided to the debugger by
174 the Perl interpreter.
176 The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline>
177 via glob assignment) contains the text from C<$filename>, with each
178 element corresponding to a single line of C<$filename>. Additionally,
179 breakable lines will be dualvars with the numeric component being the
180 memory address of a COP node. Non-breakable lines are dualvar to 0.
182 The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
183 assignment) contains breakpoints and actions. The keys are line numbers;
184 you can set individual values, but not the whole hash. The Perl interpreter
185 uses this hash to determine where breakpoints have been set. Any true value is
186 considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>.
187 Values are magical in numeric context: 1 if the line is breakable, 0 if not.
189 The scalar C<${"_<$filename"}> simply contains the string C<_<$filename>.
190 This is also the case for evaluated strings that contain subroutines, or
191 which are currently being executed. The $filename for C<eval>ed strings looks
192 like C<(eval 34)> or C<(re_eval 19)>.
194 =head1 DEBUGGER STARTUP
196 When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
197 non-interactive sessions, C<.perldb> for interactive ones) that can set a number
198 of options. In addition, this file may define a subroutine C<&afterinit>
199 that will be executed (in the debugger's context) after the debugger has
202 Next, it checks the C<PERLDB_OPTS> environment variable and treats its
203 contents as the argument of a C<o> command in the debugger.
205 =head2 STARTUP-ONLY OPTIONS
207 The following options can only be specified at startup.
208 To set them in your rcfile, add a call to
209 C<&parse_options("optionName=new_value")>.
215 the TTY to use for debugging i/o.
219 if set, goes in NonStop mode. On interrupt, if TTY is not set,
220 uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using
221 Term::Rendezvous. Current variant is to have the name of TTY in this
226 if false, a dummy ReadLine is used, so you can debug
227 ReadLine applications.
231 if true, no i/o is performed until interrupt.
235 file or pipe to print line number info to. If it is a
236 pipe, a short "emacs like" message is used.
240 host:port to connect to on remote host for remote debugging.
244 file to store session history to. There is no default and so no
245 history file is written unless this variable is explicitly set.
249 number of commands to store to the file specified in C<HistFile>.
256 &parse_options("NonStop=1 LineInfo=db.out");
257 sub afterinit { $trace = 1; }
259 The script will run without human intervention, putting trace
260 information into C<db.out>. (If you interrupt it, you had better
261 reset C<LineInfo> to something I<interactive>!)
263 =head1 INTERNALS DESCRIPTION
265 =head2 DEBUGGER INTERFACE VARIABLES
267 Perl supplies the values for C<%sub>. It effectively inserts
268 a C<&DB::DB();> in front of each place that can have a
269 breakpoint. At each subroutine call, it calls C<&DB::sub> with
270 C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
271 {require 'perl5db.pl'}> before the first line.
273 After each C<require>d file is compiled, but before it is executed, a
274 call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
275 is the expanded name of the C<require>d file (as found via C<%INC>).
277 =head3 IMPORTANT INTERNAL VARIABLES
281 Used to control when the debugger will attempt to acquire another TTY to be
286 =item * 1 - on C<fork()>
288 =item * 2 - debugger is started inside debugger
290 =item * 4 - on startup
296 The value -2 indicates that no return value should be printed.
297 Any other positive value causes C<DB::sub> to print return values.
301 The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
302 contents of C<@_> when C<DB::eval> is called.
306 Determines what messages (if any) will get printed when a subroutine (or eval)
307 is entered or exited.
311 =item * 0 - No enter/exit messages
313 =item * 1 - Print I<entering> messages on subroutine entry
315 =item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
317 =item * 4 - Extended messages: C<< <in|out> I<context>=I<fully-qualified sub name> from I<file>:I<line> >>. If no other flag is on, acts like 1+4.
319 =item * 8 - Adds parameter information to messages, and overloaded stringify and tied FETCH is enabled on the printed arguments. Ignored if C<4> is not on.
321 =item * 16 - Adds C<I<context> return from I<subname>: I<value>> messages on subroutine/eval exit. Ignored if C<4> is is not on.
325 To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
326 The debugger internally juggles the value of C<$frame> during execution to
327 protect external modules that the debugger uses from getting traced.
331 Tracks current debugger nesting level. Used to figure out how many
332 C<E<lt>E<gt>> pairs to surround the line number with when the debugger
333 outputs a prompt. Also used to help determine if the program has finished
334 during command parsing.
336 =head4 C<$onetimeDump>
338 Controls what (if anything) C<DB::eval()> will print after evaluating an
343 =item * C<undef> - don't print anything
345 =item * C<dump> - use C<dumpvar.pl> to display the value returned
347 =item * C<methods> - print the methods callable on the first item returned
351 =head4 C<$onetimeDumpDepth>
353 Controls how far down C<dumpvar.pl> will go before printing C<...> while
354 dumping a structure. Numeric. If C<undef>, print all levels.
358 Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
359 which is called before every statement, checks this and puts the user into
360 command mode if it finds C<$signal> set to a true value.
364 Controls behavior during single-stepping. Stacked in C<@stack> on entry to
365 each subroutine; popped again at the end of each subroutine.
369 =item * 0 - run continuously.
371 =item * 1 - single-step, go into subs. The C<s> command.
373 =item * 2 - single-step, don't go into subs. The C<n> command.
375 =item * 4 - print current sub depth (turned on to force this when C<too much
382 Controls the output of trace information.
386 =item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
388 =item * 2 - watch expressions are active
390 =item * 4 - user defined a C<watchfunction()> in C<afterinit()>
394 =head4 C<$slave_editor>
396 1 if C<LINEINFO> was directed to a pipe; 0 otherwise.
400 Stack of filehandles that C<DB::readline()> will read commands from.
401 Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
405 Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
406 supplied by the Perl interpreter to the debugger. Contains the source.
410 Previous values of watch expressions. First set when the expression is
411 entered; reset whenever the watch expression changes.
415 Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
416 so that the debugger can substitute safe values while it's running, and
417 restore them when it returns control.
421 Saves the current value of C<$single> on entry to a subroutine.
422 Manipulated by the C<c> command to turn off tracing in all subs above the
427 The 'watch' expressions: to be evaluated before each line is executed.
431 The typeahead buffer, used by C<DB::readline>.
435 Command aliases. Stored as character strings to be substituted for a command
438 =head4 C<%break_on_load>
440 Keys are file names, values are 1 (break when this file is loaded) or undef
441 (don't break when it is loaded).
445 Keys are line numbers, values are C<condition\0action>. If used in numeric
446 context, values are 0 if not breakable, 1 if breakable, no matter what is
447 in the actual hash entry.
449 =head4 C<%had_breakpoints>
451 Keys are file names; values are bitfields:
455 =item * 1 - file has a breakpoint in it.
457 =item * 2 - file has an action in it.
461 A zero or undefined value means this file has neither.
465 Stores the debugger options. These are character string values.
469 Saves breakpoints for code that hasn't been compiled yet.
470 Keys are subroutine names, values are:
474 =item * C<compile> - break when this sub is compiled
476 =item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
480 =head4 C<%postponed_file>
482 This hash keeps track of breakpoints that need to be set for files that have
483 not yet been compiled. Keys are filenames; values are references to hashes.
484 Each of these hashes is keyed by line number, and its values are breakpoint
485 definitions (C<condition\0action>).
487 =head1 DEBUGGER INITIALIZATION
489 The debugger's initialization actually jumps all over the place inside this
490 package. This is because there are several BEGIN blocks (which of course
491 execute immediately) spread through the code. Why is that?
493 The debugger needs to be able to change some things and set some things up
494 before the debugger code is compiled; most notably, the C<$deep> variable that
495 C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
496 debugger has to turn off warnings while the debugger code is compiled, but then
497 restore them to their original setting before the program being debugged begins
500 The first C<BEGIN> block simply turns off warnings by saving the current
501 setting of C<$^W> and then setting it to zero. The second one initializes
502 the debugger variables that are needed before the debugger begins executing.
503 The third one puts C<$^X> back to its former value.
505 We'll detail the second C<BEGIN> block later; just remember that if you need
506 to initialize something before the debugger starts really executing, that's
513 BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
517 $^V =~ /^v(\d+\.\d+)/;
518 feature->import(":$1");
521 # Debugger for Perl 5.00x; perl5db.pl patch level:
524 $header = "perl5db.pl version $VERSION";
526 =head1 DEBUGGER ROUTINES
530 This function replaces straight C<eval()> inside the debugger; it simplifies
531 the process of evaluating code in the user's context.
533 The code to be evaluated is passed via the package global variable
534 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
536 Before we do the C<eval()>, we preserve the current settings of C<$trace>,
537 C<$single>, C<$^D> and C<$usercontext>. The latter contains the
538 preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
539 user's current package, grabbed when C<DB::DB> got control. This causes the
540 proper context to be used when the eval is actually done. Afterward, we
541 restore C<$trace>, C<$single>, and C<$^D>.
543 Next we need to handle C<$@> without getting confused. We save C<$@> in a
544 local lexical, localize C<$saved[0]> (which is where C<save()> will put
545 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
546 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
547 considered sane by the debugger. If there was an C<eval()> error, we print
548 it on the debugger's output. If C<$onetimedump> is defined, we call
549 C<dumpit> if it's set to 'dump', or C<methods> if it's set to
550 'methods'. Setting it to something else causes the debugger to do the eval
551 but not print the result - handy if you want to do something else with it
552 (the "watch expressions" code does this to get the value of the watch
553 expression but not show it unless it matters).
555 In any case, we then return the list of output from C<eval> to the caller,
556 and unwinding restores the former version of C<$@> in C<@saved> as well
557 (the localization of C<$saved[0]> goes away at the end of this scope).
559 =head3 Parameters and variables influencing execution of DB::eval()
561 C<DB::eval> isn't parameterized in the standard way; this is to keep the
562 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
563 The variables listed below influence C<DB::eval()>'s execution directly.
567 =item C<$evalarg> - the thing to actually be eval'ed
569 =item C<$trace> - Current state of execution tracing
571 =item C<$single> - Current state of single-stepping
573 =item C<$onetimeDump> - what is to be displayed after the evaluation
575 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
579 The following variables are altered by C<DB::eval()> during its execution. They
580 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
584 =item C<@res> - used to capture output from actual C<eval>.
586 =item C<$otrace> - saved value of C<$trace>.
588 =item C<$osingle> - saved value of C<$single>.
590 =item C<$od> - saved value of C<$^D>.
592 =item C<$saved[0]> - saved value of C<$@>.
594 =item $\ - for output of C<$@> if there is an evaluation error.
598 =head3 The problem of lexicals
600 The context of C<DB::eval()> presents us with some problems. Obviously,
601 we want to be 'sandboxed' away from the debugger's internals when we do
602 the eval, but we need some way to control how punctuation variables and
603 debugger globals are used.
605 We can't use local, because the code inside C<DB::eval> can see localized
606 variables; and we can't use C<my> either for the same reason. The code
607 in this routine compromises and uses C<my>.
609 After this routine is over, we don't have user code executing in the debugger's
610 context, so we can use C<my> freely.
614 ############################################## Begin lexical danger zone
616 # 'my' variables used here could leak into (that is, be visible in)
617 # the context that the code being evaluated is executing in. This means that
618 # the code could modify the debugger's variables.
620 # Fiddling with the debugger's context could be Bad. We insulate things as
625 # 'my' would make it visible from user code
626 # but so does local! --tchrist
627 # Remember: this localizes @DB::res, not @main::res.
631 # Try to keep the user code from messing with us. Save these so that
632 # even if the eval'ed code changes them, we can put them back again.
633 # Needed because the user could refer directly to the debugger's
634 # package globals (and any 'my' variables in this containing scope)
635 # inside the eval(), and we want to try to stay safe.
636 local $otrace = $trace;
637 local $osingle = $single;
640 # Untaint the incoming eval() argument.
641 { ($evalarg) = $evalarg =~ /(.*)/s; }
643 # $usercontext built in DB::DB near the comment
644 # "set up the context for DB::eval ..."
645 # Evaluate and save any results.
646 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
648 # Restore those old values.
654 # Save the current value of $@, and preserve it in the debugger's copy
655 # of the saved precious globals.
658 # Since we're only saving $@, we only have to localize the array element
659 # that it will be stored in.
660 local $saved[0]; # Preserve the old value of $@
663 # Now see whether we need to report an error back to the user.
669 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
670 # are package globals.
671 elsif ($onetimeDump) {
672 if ( $onetimeDump eq 'dump' ) {
673 local $option{dumpDepth} = $onetimedumpDepth
674 if defined $onetimedumpDepth;
675 dumpit( $OUT, \@res );
677 elsif ( $onetimeDump eq 'methods' ) {
680 } ## end elsif ($onetimeDump)
684 ############################################## End lexical danger zone
686 # After this point it is safe to introduce lexicals.
687 # The code being debugged will be executing in its own context, and
688 # can't see the inside of the debugger.
690 # However, one should not overdo it: leave as much control from outside as
691 # possible. If you make something a lexical, it's not going to be addressable
692 # from outside the debugger even if you know its name.
694 # This file is automatically included if you do perl -d.
695 # It's probably not useful to include this yourself.
697 # Before venturing further into these twisty passages, it is
698 # wise to read the perldebguts man page or risk the ire of dragons.
700 # (It should be noted that perldebguts will tell you a lot about
701 # the underlying mechanics of how the debugger interfaces into the
702 # Perl interpreter, but not a lot about the debugger itself. The new
703 # comments in this code try to address this problem.)
705 # Note that no subroutine call is possible until &DB::sub is defined
706 # (for subroutines defined outside of the package DB). In fact the same is
707 # true if $deep is not defined.
709 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
711 # modified Perl debugger, to be run from Emacs in perldb-mode
712 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
713 # Johan Vromans -- upgrade to 4.0 pl 10
714 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
716 # (We have made efforts to clarify the comments in the change log
717 # in other places; some of them may seem somewhat obscure as they
718 # were originally written, and explaining them away from the code
719 # in question seems conterproductive.. -JM)
721 ########################################################################
723 # + A lot of things changed after 0.94. First of all, core now informs
724 # debugger about entry into XSUBs, overloaded operators, tied operations,
725 # BEGIN and END. Handy with 'O f=2'.
726 # + This can make debugger a little bit too verbose, please be patient
727 # and report your problems promptly.
728 # + Now the option frame has 3 values: 0,1,2. XXX Document!
729 # + Note that if DESTROY returns a reference to the object (or object),
730 # the deletion of data may be postponed until the next function call,
731 # due to the need to examine the return value.
734 # + 'v' command shows versions.
737 # + 'v' command shows version of readline.
738 # primitive completion works (dynamic variables, subs for 'b' and 'l',
739 # options). Can 'p %var'
740 # + Better help ('h <' now works). New commands <<, >>, {, {{.
741 # {dump|print}_trace() coded (to be able to do it from <<cmd).
742 # + 'c sub' documented.
743 # + At last enough magic combined to stop after the end of debuggee.
744 # + !! should work now (thanks to Emacs bracket matching an extra
745 # ']' in a regexp is caught).
746 # + 'L', 'D' and 'A' span files now (as documented).
747 # + Breakpoints in 'require'd code are possible (used in 'R').
748 # + Some additional words on internal work of debugger.
749 # + 'b load filename' implemented.
750 # + 'b postpone subr' implemented.
751 # + now only 'q' exits debugger (overwritable on $inhibit_exit).
752 # + When restarting debugger breakpoints/actions persist.
753 # + Buglet: When restarting debugger only one breakpoint/action per
754 # autoloaded function persists.
756 # Changes: 0.97: NonStop will not stop in at_exit().
757 # + Option AutoTrace implemented.
758 # + Trace printed differently if frames are printed too.
759 # + new 'inhibitExit' option.
760 # + printing of a very long statement interruptible.
761 # Changes: 0.98: New command 'm' for printing possible methods
762 # + 'l -' is a synonym for '-'.
763 # + Cosmetic bugs in printing stack trace.
764 # + 'frame' & 8 to print "expanded args" in stack trace.
765 # + Can list/break in imported subs.
766 # + new 'maxTraceLen' option.
767 # + frame & 4 and frame & 8 granted.
769 # + nonstoppable lines do not have ':' near the line number.
770 # + 'b compile subname' implemented.
771 # + Will not use $` any more.
772 # + '-' behaves sane now.
773 # Changes: 0.99: Completion for 'f', 'm'.
774 # + 'm' will remove duplicate names instead of duplicate functions.
775 # + 'b load' strips trailing whitespace.
776 # completion ignores leading '|'; takes into account current package
777 # when completing a subroutine name (same for 'l').
778 # Changes: 1.07: Many fixed by tchrist 13-March-2000
780 # + Added bare minimal security checks on perldb rc files, plus
781 # comments on what else is needed.
782 # + Fixed the ornaments that made "|h" completely unusable.
783 # They are not used in print_help if they will hurt. Strip pod
784 # if we're paging to less.
785 # + Fixed mis-formatting of help messages caused by ornaments
786 # to restore Larry's original formatting.
787 # + Fixed many other formatting errors. The code is still suboptimal,
788 # and needs a lot of work at restructuring. It's also misindented
790 # + Fixed bug where trying to look at an option like your pager
792 # + Fixed some $? processing. Note: if you use csh or tcsh, you will
793 # lose. You should consider shell escapes not using their shell,
794 # or else not caring about detailed status. This should really be
795 # unified into one place, too.
796 # + Fixed bug where invisible trailing whitespace on commands hoses you,
797 # tricking Perl into thinking you weren't calling a debugger command!
798 # + Fixed bug where leading whitespace on commands hoses you. (One
799 # suggests a leading semicolon or any other irrelevant non-whitespace
800 # to indicate literal Perl code.)
801 # + Fixed bugs that ate warnings due to wrong selected handle.
802 # + Fixed a precedence bug on signal stuff.
803 # + Fixed some unseemly wording.
804 # + Fixed bug in help command trying to call perl method code.
805 # + Fixed to call dumpvar from exception handler. SIGPIPE killed us.
807 # + Added some comments. This code is still nasty spaghetti.
808 # + Added message if you clear your pre/post command stacks which was
809 # very easy to do if you just typed a bare >, <, or {. (A command
810 # without an argument should *never* be a destructive action; this
811 # API is fundamentally screwed up; likewise option setting, which
812 # is equally buggered.)
813 # + Added command stack dump on argument of "?" for >, <, or {.
814 # + Added a semi-built-in doc viewer command that calls man with the
815 # proper %Config::Config path (and thus gets caching, man -k, etc),
816 # or else perldoc on obstreperous platforms.
817 # + Added to and rearranged the help information.
818 # + Detected apparent misuse of { ... } to declare a block; this used
819 # to work but now is a command, and mysteriously gave no complaint.
821 # Changes: 1.08: Apr 25, 2001 Jon Eveland <jweveland@yahoo.com>
823 # + This patch to perl5db.pl cleans up formatting issues on the help
824 # summary (h h) screen in the debugger. Mostly columnar alignment
825 # issues, plus converted the printed text to use all spaces, since
826 # tabs don't seem to help much here.
828 # Changes: 1.09: May 19, 2001 Ilya Zakharevich <ilya@math.ohio-state.edu>
829 # Minor bugs corrected;
830 # + Support for auto-creation of new TTY window on startup, either
831 # unconditionally, or if started as a kid of another debugger session;
832 # + New 'O'ption CreateTTY
833 # I<CreateTTY> bits control attempts to create a new TTY on events:
835 # 2: debugger is started inside debugger
837 # + Code to auto-create a new TTY window on OS/2 (currently one
838 # extra window per session - need named pipes to have more...);
839 # + Simplified interface for custom createTTY functions (with a backward
840 # compatibility hack); now returns the TTY name to use; return of ''
841 # means that the function reset the I/O handles itself;
842 # + Better message on the semantic of custom createTTY function;
843 # + Convert the existing code to create a TTY into a custom createTTY
845 # + Consistent support for TTY names of the form "TTYin,TTYout";
846 # + Switch line-tracing output too to the created TTY window;
847 # + make 'b fork' DWIM with CORE::GLOBAL::fork;
848 # + High-level debugger API cmd_*():
849 # cmd_b_load($filenamepart) # b load filenamepart
850 # cmd_b_line($lineno [, $cond]) # b lineno [cond]
851 # cmd_b_sub($sub [, $cond]) # b sub [cond]
852 # cmd_stop() # Control-C
853 # cmd_d($lineno) # d lineno (B)
854 # The cmd_*() API returns FALSE on failure; in this case it outputs
855 # the error message to the debugging output.
856 # + Low-level debugger API
857 # break_on_load($filename) # b load filename
858 # @files = report_break_on_load() # List files with load-breakpoints
859 # breakable_line_in_filename($name, $from [, $to])
860 # # First breakable line in the
861 # # range $from .. $to. $to defaults
862 # # to $from, and may be less than
864 # breakable_line($from [, $to]) # Same for the current file
865 # break_on_filename_line($name, $lineno [, $cond])
866 # # Set breakpoint,$cond defaults to
868 # break_on_filename_line_range($name, $from, $to [, $cond])
869 # # As above, on the first
870 # # breakable line in range
871 # break_on_line($lineno [, $cond]) # As above, in the current file
872 # break_subroutine($sub [, $cond]) # break on the first breakable line
873 # ($name, $from, $to) = subroutine_filename_lines($sub)
874 # # The range of lines of the text
875 # The low-level API returns TRUE on success, and die()s on failure.
877 # Changes: 1.10: May 23, 2001 Daniel Lewart <d-lewart@uiuc.edu>
879 # + Fixed warnings generated by "perl -dWe 42"
880 # + Corrected spelling errors
881 # + Squeezed Help (h) output into 80 columns
883 # Changes: 1.11: May 24, 2001 David Dyck <dcd@tc.fluke.com>
884 # + Made "x @INC" work like it used to
886 # Changes: 1.12: May 24, 2001 Daniel Lewart <d-lewart@uiuc.edu>
887 # + Fixed warnings generated by "O" (Show debugger options)
888 # + Fixed warnings generated by "p 42" (Print expression)
889 # Changes: 1.13: Jun 19, 2001 Scott.L.Miller@compaq.com
890 # + Added windowSize option
891 # Changes: 1.14: Oct 9, 2001 multiple
892 # + Clean up after itself on VMS (Charles Lane in 12385)
893 # + Adding "@ file" syntax (Peter Scott in 12014)
894 # + Debug reloading selfloaded stuff (Ilya Zakharevich in 11457)
895 # + $^S and other debugger fixes (Ilya Zakharevich in 11120)
896 # + Forgot a my() declaration (Ilya Zakharevich in 11085)
897 # Changes: 1.15: Nov 6, 2001 Michael G Schwern <schwern@pobox.com>
898 # + Updated 1.14 change log
899 # + Added *dbline explanatory comments
900 # + Mentioning perldebguts man page
901 # Changes: 1.16: Feb 15, 2002 Mark-Jason Dominus <mjd@plover.com>
902 # + $onetimeDump improvements
903 # Changes: 1.17: Feb 20, 2002 Richard Foley <richard.foley@rfi.net>
904 # Moved some code to cmd_[.]()'s for clarity and ease of handling,
905 # rationalised the following commands and added cmd_wrapper() to
906 # enable switching between old and frighteningly consistent new
907 # behaviours for diehards: 'o CommandSet=pre580' (sigh...)
908 # a(add), A(del) # action expr (added del by line)
909 # + b(add), B(del) # break [line] (was b,D)
910 # + w(add), W(del) # watch expr (was W,W)
911 # # added del by expr
912 # + h(summary), h h(long) # help (hh) (was h h,h)
913 # + m(methods), M(modules) # ... (was m,v)
914 # + o(option) # lc (was O)
915 # + v(view code), V(view Variables) # ... (was w,V)
916 # Changes: 1.18: Mar 17, 2002 Richard Foley <richard.foley@rfi.net>
917 # + fixed missing cmd_O bug
918 # Changes: 1.19: Mar 29, 2002 Spider Boardman
919 # + Added missing local()s -- DB::DB is called recursively.
920 # Changes: 1.20: Feb 17, 2003 Richard Foley <richard.foley@rfi.net>
921 # + pre'n'post commands no longer trashed with no args
922 # + watch val joined out of eval()
923 # Changes: 1.21: Jun 04, 2003 Joe McMahon <mcmahon@ibiblio.org>
924 # + Added comments and reformatted source. No bug fixes/enhancements.
925 # + Includes cleanup by Robin Barker and Jarkko Hietaniemi.
926 # Changes: 1.22 Jun 09, 2003 Alex Vandiver <alexmv@MIT.EDU>
927 # + Flush stdout/stderr before the debugger prompt is printed.
928 # Changes: 1.23: Dec 21, 2003 Dominique Quatravaux
929 # + Fix a side-effect of bug #24674 in the perl debugger ("odd taint bug")
930 # Changes: 1.24: Mar 03, 2004 Richard Foley <richard.foley@rfi.net>
931 # + Added command to save all debugger commands for sourcing later.
932 # + Added command to display parent inheritance tree of given class.
933 # + Fixed minor newline in history bug.
934 # Changes: 1.25: Apr 17, 2004 Richard Foley <richard.foley@rfi.net>
935 # + Fixed option bug (setting invalid options + not recognising valid short forms)
936 # Changes: 1.26: Apr 22, 2004 Richard Foley <richard.foley@rfi.net>
937 # + unfork the 5.8.x and 5.9.x debuggers.
938 # + whitespace and assertions call cleanup across versions
939 # + H * deletes (resets) history
940 # + i now handles Class + blessed objects
941 # Changes: 1.27: May 09, 2004 Richard Foley <richard.foley@rfi.net>
942 # + updated pod page references - clunky.
943 # + removed windowid restriction for forking into an xterm.
944 # + more whitespace again.
945 # + wrapped restart and enabled rerun [-n] (go back n steps) command.
946 # Changes: 1.28: Oct 12, 2004 Richard Foley <richard.foley@rfi.net>
947 # + Added threads support (inc. e and E commands)
948 # Changes: 1.29: Nov 28, 2006 Bo Lindbergh <blgl@hagernas.com>
949 # + Added macosx_get_fork_TTY support
950 # Changes: 1.30: Mar 06, 2007 Andreas Koenig <andk@cpan.org>
951 # + Added HistFile, HistSize
953 # + Remove support for assertions and -A
954 # + stop NEXT::AUTOLOAD from emitting warnings under the debugger. RT #25053
955 # + "update for Mac OS X 10.5" [finding the tty device]
956 # + "What I needed to get the forked debugger to work" [on VMS]
957 # + [perl #57016] debugger: o warn=0 die=0 ignored
958 # + Note, but don't use, PERLDBf_SAVESRC
959 # + Fix #7013: lvalue subs not working inside debugger
960 # Changes: 1.32: Jun 03, 2009 Jonathan Leto <jonathan@leto.net>
961 # + Fix bug where a key _< with undefined value was put into the symbol table
962 # + when the $filename variable is not set
964 # + Debugger prints lines to the remote port when it forks and openes a new port (f633fd2)
965 # + The debugger now continues to use RemotePort when it's been configured to use it. (11653f7)
966 # + Stop using $ENV{LESS} for parameters not intended for less (d463cf2)
967 # + Configure has a path to less and perl5db.pl can use it (bf320d6)
968 # + Die with $@ instead of empty message (86755f4)
969 # + Remove extra/useless $@ check after eval { require PadWalker } (which is still checked) (dab8d6d)
970 # + Promote eval( "require ..." ) to eval { require ... } (4a49187)
971 # + Promote eval { require( ... )} || die to mere require( ... ) (999f23b)
972 # + Remove indirect object notation from debugger (bee4b46)
973 # + Document that @{$main::{'_<'.$filename}} lines are dualvar to (COP*). (7e17a74)
974 # + Remove MacOS classic support from the debugger. (2b894b7)
975 ########################################################################
977 =head1 DEBUGGER INITIALIZATION
979 The debugger starts up in phases.
983 First, it initializes the environment it wants to run in: turning off
984 warnings during its own compilation, defining variables which it will need
985 to avoid warnings later, setting itself up to not exit when the program
986 terminates, and defaulting to printing return values for the C<r> command.
990 # Needed for the statement after exec():
992 # This BEGIN block is simply used to switch off warnings during debugger
993 # compilation. Probably it would be better practice to fix the warnings,
994 # but this is how it's done at the moment.
999 } # Switch compilation warnings off until another BEGIN.
1001 local ($^W) = 0; # Switch run-time warnings off during init.
1003 =head2 THREADS SUPPORT
1005 If we are running under a threaded Perl, we require threads and threads::shared
1006 if the environment variable C<PERL5DB_THREADED> is set, to enable proper
1007 threaded debugger control. C<-dt> can also be used to set this.
1009 Each new thread will be announced and the debugger prompt will always inform
1010 you of each new thread created. It will also indicate the thread id in which
1011 we are currently running within the prompt like this:
1015 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
1016 command prompt. The prompt will show: C<[0]> when running under threads, but
1017 not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
1019 While running under threads, when you set or delete a breakpoint (etc.), this
1020 will apply to all threads, not just the currently running one. When you are
1021 in a currently executing thread, you will stay there until it completes. With
1022 the current implementation it is not currently possible to hop from one thread
1025 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
1027 Note that threading support was built into the debugger as of Perl version
1028 C<5.8.6> and debugger version C<1.2.8>.
1033 # ensure we can share our non-threaded variables or no-op
1034 if ($ENV{PERL5DB_THREADED}) {
1036 require threads::shared;
1037 import threads::shared qw(share);
1041 print "Threads support enabled\n";
1048 # This would probably be better done with "use vars", but that wasn't around
1049 # when this code was originally written. (Neither was "use strict".) And on
1050 # the principle of not fiddling with something that was working, this was
1053 # These variables control the execution of 'dumpvar.pl'.
1054 $dumpvar::hashDepth,
1055 $dumpvar::arrayDepth,
1056 $dumpvar::dumpDBFiles,
1057 $dumpvar::dumpPackages,
1058 $dumpvar::quoteHighBit,
1059 $dumpvar::printUndef,
1060 $dumpvar::globPrint,
1061 $dumpvar::usageOnly,
1063 # used to save @ARGV and extract any debugger-related flags.
1066 # used to control die() reporting in diesignal()
1069 # used to prevent multiple entries to diesignal()
1070 # (if for instance diesignal() itself dies)
1073 # used to prevent the debugger from running nonstop
1079 # without threads, $filename is not defined until DB::DB is called
1080 foreach my $k (keys (%INC)) {
1081 &share(\$main::{'_<'.$filename}) if defined $filename;
1084 # Command-line + PERLLIB:
1085 # Save the contents of @INC before they are modified elsewhere.
1088 # This was an attempt to clear out the previous values of various
1089 # trapped errors. Apparently it didn't help. XXX More info needed!
1090 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
1092 # We set these variables to safe values. We don't want to blindly turn
1093 # off warnings, because other packages may still want them.
1094 $trace = $signal = $single = 0; # Uninitialized warning suppression
1095 # (local $^W cannot help - other packages!).
1097 # Default to not exiting when program finishes; print the return
1098 # value when the 'r' command is used to return from a subroutine.
1099 $inhibit_exit = $option{PrintRet} = 1;
1101 # Default to 1 so the prompt will display the first line.
1102 $trace_to_depth = 1;
1104 =head1 OPTION PROCESSING
1106 The debugger's options are actually spread out over the debugger itself and
1107 C<dumpvar.pl>; some of these are variables to be set, while others are
1108 subs to be called with a value. To try to make this a little easier to
1109 manage, the debugger uses a few data structures to define what options
1110 are legal and how they are to be processed.
1112 First, the C<@options> array defines the I<names> of all the options that
1118 CommandSet HistFile HistSize
1119 hashDepth arrayDepth dumpDepth
1120 DumpDBFiles DumpPackages DumpReused
1121 compactDump veryCompact quote
1122 HighBit undefPrint globPrint
1123 PrintRet UsageOnly frame
1125 ReadLine NonStop LineInfo
1126 maxTraceLen recallCommand ShellBang
1127 pager tkRunning ornaments
1128 signalLevel warnLevel dieLevel
1129 inhibit_exit ImmediateStop bareStringify
1130 CreateTTY RemotePort windowSize
1134 @RememberOnROptions = qw(DollarCaretP);
1138 Second, C<optionVars> lists the variables that each option uses to save its
1144 hashDepth => \$dumpvar::hashDepth,
1145 arrayDepth => \$dumpvar::arrayDepth,
1146 CommandSet => \$CommandSet,
1147 DumpDBFiles => \$dumpvar::dumpDBFiles,
1148 DumpPackages => \$dumpvar::dumpPackages,
1149 DumpReused => \$dumpvar::dumpReused,
1150 HighBit => \$dumpvar::quoteHighBit,
1151 undefPrint => \$dumpvar::printUndef,
1152 globPrint => \$dumpvar::globPrint,
1153 UsageOnly => \$dumpvar::usageOnly,
1154 CreateTTY => \$CreateTTY,
1155 bareStringify => \$dumpvar::bareStringify,
1157 AutoTrace => \$trace,
1158 inhibit_exit => \$inhibit_exit,
1159 maxTraceLen => \$maxtrace,
1160 ImmediateStop => \$ImmediateStop,
1161 RemotePort => \$remoteport,
1162 windowSize => \$window,
1163 HistFile => \$histfile,
1164 HistSize => \$histsize,
1169 Third, C<%optionAction> defines the subroutine to be called to process each
1175 compactDump => \&dumpvar::compactDump,
1176 veryCompact => \&dumpvar::veryCompact,
1177 quote => \&dumpvar::quote,
1180 ReadLine => \&ReadLine,
1181 NonStop => \&NonStop,
1182 LineInfo => \&LineInfo,
1183 recallCommand => \&recallCommand,
1184 ShellBang => \&shellBang,
1186 signalLevel => \&signalLevel,
1187 warnLevel => \&warnLevel,
1188 dieLevel => \&dieLevel,
1189 tkRunning => \&tkRunning,
1190 ornaments => \&ornaments,
1191 RemotePort => \&RemotePort,
1192 DollarCaretP => \&DollarCaretP,
1197 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1202 # Note that this list is not complete: several options not listed here
1203 # actually require that dumpvar.pl be loaded for them to work, but are
1204 # not in the table. A subsequent patch will correct this problem; for
1205 # the moment, we're just recommenting, and we are NOT going to change
1208 compactDump => 'dumpvar.pl',
1209 veryCompact => 'dumpvar.pl',
1210 quote => 'dumpvar.pl',
1215 There are a number of initialization-related variables which can be set
1216 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1217 variable. These are:
1221 =item C<$rl> - readline control XXX needs more explanation
1223 =item C<$warnLevel> - whether or not debugger takes over warning handling
1225 =item C<$dieLevel> - whether or not debugger takes over die handling
1227 =item C<$signalLevel> - whether or not debugger takes over signal handling
1229 =item C<$pre> - preprompt actions (array reference)
1231 =item C<$post> - postprompt actions (array reference)
1235 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1237 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1243 # These guys may be defined in $ENV{PERL5DB} :
1244 $rl = 1 unless defined $rl;
1245 $warnLevel = 1 unless defined $warnLevel;
1246 $dieLevel = 1 unless defined $dieLevel;
1247 $signalLevel = 1 unless defined $signalLevel;
1248 $pre = [] unless defined $pre;
1249 $post = [] unless defined $post;
1250 $pretype = [] unless defined $pretype;
1251 $CreateTTY = 3 unless defined $CreateTTY;
1252 $CommandSet = '580' unless defined $CommandSet;
1257 share($signalLevel);
1267 The default C<die>, C<warn>, and C<signal> handlers are set up.
1271 warnLevel($warnLevel);
1272 dieLevel($dieLevel);
1273 signalLevel($signalLevel);
1277 The pager to be used is needed next. We try to get it from the
1278 environment first. If it's not defined there, we try to find it in
1279 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1280 then call the C<pager()> function to save the pager name.
1284 # This routine makes sure $pager is set up so that '|' can use it.
1287 # If PAGER is defined in the environment, use it.
1291 # If not, see if Config.pm defines it.
1292 : eval { require Config }
1293 && defined $Config::Config{pager}
1294 ? $Config::Config{pager}
1296 # If not, fall back to 'more'.
1299 unless defined $pager;
1303 We set up the command to be used to access the man pages, the command
1304 recall character (C<!> unless otherwise defined) and the shell escape
1305 character (C<!> unless otherwise defined). Yes, these do conflict, and
1306 neither works in the debugger at the moment.
1312 # Set up defaults for command recall and shell escape (note:
1313 # these currently don't work in linemode debugging).
1314 &recallCommand("!") unless defined $prc;
1315 &shellBang("!") unless defined $psh;
1319 We then set up the gigantic string containing the debugger help.
1320 We also set the limit on the number of arguments we'll display during a
1327 # If we didn't get a default for the length of eval/stack trace args,
1329 $maxtrace = 400 unless defined $maxtrace;
1331 =head2 SETTING UP THE DEBUGGER GREETING
1333 The debugger I<greeting> helps to inform the user how many debuggers are
1334 running, and whether the current debugger is the primary or a child.
1336 If we are the primary, we just hang onto our pid so we'll have it when
1337 or if we start a child debugger. If we are a child, we'll set things up
1338 so we'll have a unique greeting and so the parent will give us our own
1341 We save the current contents of the C<PERLDB_PIDS> environment variable
1342 because we mess around with it. We'll also need to hang onto it because
1343 we'll need it if we restart.
1345 Child debuggers make a label out of the current PID structure recorded in
1346 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1347 yet so the parent will give them one later via C<resetterm()>.
1351 # Save the current contents of the environment; we're about to
1352 # much with it. We'll need this if we have to restart.
1353 $ini_pids = $ENV{PERLDB_PIDS};
1355 if ( defined $ENV{PERLDB_PIDS} ) {
1357 # We're a child. Make us a label out of the current PID structure
1358 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1359 # a term yet so the parent will give us one later via resetterm().
1361 my $env_pids = $ENV{PERLDB_PIDS};
1362 $pids = "[$env_pids]";
1364 # Unless we are on OpenVMS, all programs under the DCL shell run under
1367 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1371 $ENV{PERLDB_PIDS} .= "->$$";
1375 } ## end if (defined $ENV{PERLDB_PIDS...
1378 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1379 # child debugger, and mark us as the parent, so we'll know to set up
1380 # more TTY's is we have to.
1381 $ENV{PERLDB_PIDS} = "$$";
1388 # Sets up $emacs as a synonym for $slave_editor.
1389 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1391 =head2 READING THE RC FILE
1393 The debugger will read a file of initialization options if supplied. If
1394 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1398 # As noted, this test really doesn't check accurately that the debugger
1399 # is running at a terminal or not.
1401 my $dev_tty = '/dev/tty';
1402 $dev_tty = 'TT:' if ($^O eq 'VMS');
1403 if ( -e $dev_tty ) { # this is the wrong metric!
1404 $rcfile = ".perldb";
1407 $rcfile = "perldb.ini";
1412 The debugger does a safety test of the file to be read. It must be owned
1413 either by the current user or root, and must only be writable by the owner.
1417 # This wraps a safety test around "do" to read and evaluate the init file.
1419 # This isn't really safe, because there's a race
1420 # between checking and opening. The solution is to
1421 # open and fstat the handle, but then you have to read and
1422 # eval the contents. But then the silly thing gets
1423 # your lexical scope, which is unfortunate at best.
1427 # Just exactly what part of the word "CORE::" don't you understand?
1428 local $SIG{__WARN__};
1429 local $SIG{__DIE__};
1431 unless ( is_safe_file($file) ) {
1432 CORE::warn <<EO_GRIPE;
1433 perldb: Must not source insecure rcfile $file.
1434 You or the superuser must be the owner, and it must not
1435 be writable by anyone but its owner.
1438 } ## end unless (is_safe_file($file...
1441 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1442 } ## end sub safe_do
1444 # This is the safety test itself.
1446 # Verifies that owner is either real user or superuser and that no
1447 # one but owner may write to it. This function is of limited use
1448 # when called on a path instead of upon a handle, because there are
1449 # no guarantees that filename (by dirent) whose file (by ino) is
1450 # eventually accessed is the same as the one tested.
1451 # Assumes that the file's existence is not in doubt.
1454 stat($path) || return; # mysteriously vaporized
1455 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1457 return 0 if $uid != 0 && $uid != $<;
1458 return 0 if $mode & 022;
1460 } ## end sub is_safe_file
1462 # If the rcfile (whichever one we decided was the right one to read)
1463 # exists, we safely do it.
1465 safe_do("./$rcfile");
1468 # If there isn't one here, try the user's home directory.
1469 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1470 safe_do("$ENV{HOME}/$rcfile");
1473 # Else try the login directory.
1474 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1475 safe_do("$ENV{LOGDIR}/$rcfile");
1478 # If the PERLDB_OPTS variable has options in it, parse those out next.
1479 if ( defined $ENV{PERLDB_OPTS} ) {
1480 parse_options( $ENV{PERLDB_OPTS} );
1485 The last thing we do during initialization is determine which subroutine is
1486 to be used to obtain a new terminal when a new debugger is started. Right now,
1487 the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
1492 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1493 # Works if you're running an xterm or xterm-like window, or you're on
1494 # OS/2, or on Mac OS X. This may need some expansion.
1496 if (not defined &get_fork_TTY) # only if no routine exists
1498 if ( defined $remoteport ) {
1499 # Expect an inetd-like server
1500 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1502 elsif (defined $ENV{TERM} # If we know what kind
1503 # of terminal this is,
1504 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1505 and defined $ENV{DISPLAY} # and what display it's on,
1508 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1510 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1511 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1513 elsif ( $^O eq 'darwin' # If this is Mac OS X
1514 and defined $ENV{TERM_PROGRAM} # and we're running inside
1515 and $ENV{TERM_PROGRAM}
1516 eq 'Apple_Terminal' # Terminal.app
1519 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1521 } ## end if (not defined &get_fork_TTY...
1523 # untaint $^O, which may have been tainted by the last statement.
1524 # see bug [perl #24674]
1528 # Here begin the unreadable code. It needs fixing.
1530 =head2 RESTART PROCESSING
1532 This section handles the restart command. When the C<R> command is invoked, it
1533 tries to capture all of the state it can into environment variables, and
1534 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1535 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1536 the R command stuffed into the environment variables.
1538 PERLDB_RESTART - flag only, contains no restart data itself.
1539 PERLDB_HIST - command history, if it's available
1540 PERLDB_ON_LOAD - breakpoints set by the rc file
1541 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1542 PERLDB_VISITED - files that had breakpoints
1543 PERLDB_FILE_... - breakpoints for a file
1544 PERLDB_OPT - active options
1545 PERLDB_INC - the original @INC
1546 PERLDB_PRETYPE - preprompt debugger actions
1547 PERLDB_PRE - preprompt Perl code
1548 PERLDB_POST - post-prompt Perl code
1549 PERLDB_TYPEAHEAD - typeahead captured by readline()
1551 We chug through all these variables and plug the values saved in them
1552 back into the appropriate spots in the debugger.
1556 if ( exists $ENV{PERLDB_RESTART} ) {
1558 # We're restarting, so we don't need the flag that says to restart anymore.
1559 delete $ENV{PERLDB_RESTART};
1562 @hist = get_list('PERLDB_HIST');
1563 %break_on_load = get_list("PERLDB_ON_LOAD");
1564 %postponed = get_list("PERLDB_POSTPONE");
1568 share(%break_on_load);
1571 # restore breakpoints/actions
1572 my @had_breakpoints = get_list("PERLDB_VISITED");
1573 for my $file_idx ( 0 .. $#had_breakpoints ) {
1574 my $filename = $had_breakpoints[$file_idx];
1575 my %pf = get_list("PERLDB_FILE_$file_idx");
1576 $postponed_file{ $filename } = \%pf if %pf;
1577 my @lines = sort {$a <=> $b} keys(%pf);
1578 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1579 for my $line_idx (0 .. $#lines) {
1580 _set_breakpoint_enabled_status(
1583 ($enabled_statuses[$line_idx] ? 1 : ''),
1589 my %opt = get_list("PERLDB_OPT");
1591 while ( ( $opt, $val ) = each %opt ) {
1592 $val =~ s/[\\\']/\\$1/g;
1593 parse_options("$opt'$val'");
1596 # restore original @INC
1597 @INC = get_list("PERLDB_INC");
1600 # return pre/postprompt actions and typeahead buffer
1601 $pretype = [ get_list("PERLDB_PRETYPE") ];
1602 $pre = [ get_list("PERLDB_PRE") ];
1603 $post = [ get_list("PERLDB_POST") ];
1604 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1605 } ## end if (exists $ENV{PERLDB_RESTART...
1607 =head2 SETTING UP THE TERMINAL
1609 Now, we'll decide how the debugger is going to interact with the user.
1610 If there's no TTY, we set the debugger to run non-stop; there's not going
1611 to be anyone there to enter commands.
1622 If there is a TTY, we have to determine who it belongs to before we can
1623 proceed. If this is a slave editor or graphical debugger (denoted by
1624 the first command-line switch being '-emacs'), we shift this off and
1625 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1631 # Is Perl being run from a slave editor or graphical debugger?
1632 # If so, don't use readline, and set $slave_editor = 1.
1634 ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) );
1635 $rl = 0, shift(@main::ARGV) if $slave_editor;
1637 #require Term::ReadLine;
1641 We then determine what the console should be on various systems:
1645 =item * Cygwin - We use C<stdin> instead of a separate device.
1649 if ( $^O eq 'cygwin' ) {
1651 # /dev/tty is binary. use stdin for textmode
1655 =item * Unix - use C</dev/tty>.
1659 elsif ( -e "/dev/tty" ) {
1660 $console = "/dev/tty";
1663 =item * Windows or MSDOS - use C<con>.
1667 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1671 =item * VMS - use C<sys$command>.
1677 # everything else is ...
1678 $console = "sys\$command";
1685 Several other systems don't use a specific console. We C<undef $console>
1686 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1687 with a slave editor, Epoc).
1691 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1693 # /dev/tty is binary. use stdin for textmode
1697 if ( $^O eq 'NetWare' ) {
1699 # /dev/tty is binary. use stdin for textmode
1703 # In OS/2, we need to use STDIN to get textmode too, even though
1704 # it pretty much looks like Unix otherwise.
1705 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1710 # EPOC also falls into the 'got to use STDIN' camp.
1711 if ( $^O eq 'epoc' ) {
1717 If there is a TTY hanging around from a parent, we use that as the console.
1721 $console = $tty if defined $tty;
1723 =head2 SOCKET HANDLING
1725 The debugger is capable of opening a socket and carrying out a debugging
1726 session over the socket.
1728 If C<RemotePort> was defined in the options, the debugger assumes that it
1729 should try to start a debugging session on that port. It builds the socket
1730 and then tries to connect the input and output filehandles to it.
1734 # Handle socket stuff.
1736 if ( defined $remoteport ) {
1738 # If RemotePort was defined in the options, connect input and output
1740 $IN = $OUT = connect_remoteport();
1741 } ## end if (defined $remoteport)
1745 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1746 this is probably a situation where multiple debuggers are running (for example,
1747 a backticked command that starts up another debugger). We create a new IN and
1748 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1756 # Two debuggers running (probably a system or a backtick that invokes
1757 # the debugger itself under the running one). create a new IN and OUT
1758 # filehandle, and do the necessary mojo to create a new tty if we
1759 # know how, and we can.
1760 create_IN_OUT(4) if $CreateTTY & 4;
1763 # If we have a console, check to see if there are separate ins and
1764 # outs to open. (They are assumed identical if not.)
1766 my ( $i, $o ) = split /,/, $console;
1767 $o = $i unless defined $o;
1769 # read/write on in, or just read, or read on STDIN.
1771 || open( IN, "<$i" )
1772 || open( IN, "<&STDIN" );
1774 # read/write/create/clobber out, or write/create/clobber out,
1775 # or merge with STDERR, or merge with STDOUT.
1777 || open( OUT, ">$o" )
1778 || open( OUT, ">&STDERR" )
1779 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1781 } ## end if ($console)
1782 elsif ( not defined $console ) {
1784 # No console. Open STDIN.
1785 open( IN, "<&STDIN" );
1787 # merge with STDERR, or with STDOUT.
1788 open( OUT, ">&STDERR" )
1789 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1790 $console = 'STDIN/OUT';
1791 } ## end elsif (not defined $console)
1793 # Keep copies of the filehandles so that when the pager runs, it
1794 # can close standard input without clobbering ours.
1795 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1796 } ## end elsif (from if(defined $remoteport))
1798 # Unbuffer DB::OUT. We need to see responses right away.
1799 my $previous = select($OUT);
1800 $| = 1; # for DB::OUT
1803 # Line info goes to debugger output unless pointed elsewhere.
1804 # Pointing elsewhere makes it possible for slave editors to
1805 # keep track of file and position. We have both a filehandle
1806 # and a I/O description to keep track of.
1807 $LINEINFO = $OUT unless defined $LINEINFO;
1808 $lineinfo = $console unless defined $lineinfo;
1809 # share($LINEINFO); # <- unable to share globs
1814 To finish initialization, we show the debugger greeting,
1815 and then call the C<afterinit()> subroutine if there is one.
1819 # Show the debugger greeting.
1820 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1821 unless ($runnonstop) {
1824 if ( $term_pid eq '-1' ) {
1825 print $OUT "\nDaughter DB session started...\n";
1828 print $OUT "\nLoading DB routines from $header\n";
1831 $slave_editor ? "enabled" : "available", ".\n"
1834 "\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
1835 } ## end else [ if ($term_pid eq '-1')
1836 } ## end unless ($runnonstop)
1837 } ## end else [ if ($notty)
1839 # XXX This looks like a bug to me.
1840 # Why copy to @ARGS and then futz with @args?
1843 # Make sure backslashes before single quotes are stripped out, and
1844 # keep args unless they are numeric (XXX why?)
1845 # s/\'/\\\'/g; # removed while not justified understandably
1846 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1849 # If there was an afterinit() sub defined, call it. It will get
1850 # executed in our scope, so it can fiddle with debugger globals.
1851 if ( defined &afterinit ) { # May be defined in $rcfile
1855 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1858 ############################################################ Subroutines
1864 This gigantic subroutine is the heart of the debugger. Called before every
1865 statement, its job is to determine if a breakpoint has been reached, and
1866 stop if so; read commands from the user, parse them, and execute
1867 them, and then send execution off to the next statement.
1869 Note that the order in which the commands are processed is very important;
1870 some commands earlier in the loop will actually alter the C<$cmd> variable
1871 to create other commands to be executed later. This is all highly I<optimized>
1872 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1873 see what's happening in any given command.
1879 # lock the debugger and get the thread id for the prompt
1882 if ($ENV{PERL5DB_THREADED}) {
1883 $tid = eval { "[".threads->tid."]" };
1886 # Check for whether we should be running continuously or not.
1887 # _After_ the perl program is compiled, $single is set to 1:
1888 if ( $single and not $second_time++ ) {
1890 # Options say run non-stop. Run until we get an interrupt.
1891 if ($runnonstop) { # Disable until signal
1892 # If there's any call stack in place, turn off single
1893 # stepping into subs throughout the stack.
1894 for ( $i = 0 ; $i <= $stack_depth ; ) {
1895 $stack[ $i++ ] &= ~1;
1898 # And we are now no longer in single-step mode.
1901 # If we simply returned at this point, we wouldn't get
1902 # the trace info. Fall on through.
1904 } ## end if ($runnonstop)
1906 elsif ($ImmediateStop) {
1908 # We are supposed to stop here; XXX probably a break.
1909 $ImmediateStop = 0; # We've processed it; turn it off
1910 $signal = 1; # Simulate an interrupt to force
1911 # us into the command loop
1913 } ## end if ($single and not $second_time...
1915 # If we're in single-step mode, or an interrupt (real or fake)
1916 # has occurred, turn off non-stop mode.
1917 $runnonstop = 0 if $single or $signal;
1919 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1920 # The code being debugged may have altered them.
1923 # Since DB::DB gets called after every line, we can use caller() to
1924 # figure out where we last were executing. Sneaky, eh? This works because
1925 # caller is returning all the extra information when called from the
1927 local ( $package, $filename, $line ) = caller;
1928 local $filename_ini = $filename;
1930 # set up the context for DB::eval, so it can properly execute
1931 # code on behalf of the user. We add the package in so that the
1932 # code is eval'ed in the proper package (not in the debugger!).
1933 local $usercontext =
1934 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' . "package $package;";
1936 # Create an alias to the active file magical array to simplify
1938 local (*dbline) = $main::{ '_<' . $filename };
1940 # Last line in the program.
1941 local $max = $#dbline;
1943 # if we have something here, see if we should break.
1945 && _is_breakpoint_enabled($filename, $line)
1946 && ( ( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1949 # Stop if the stop criterion says to just stop.
1950 if ( $stop eq '1' ) {
1954 # It's a conditional stop; eval it in the user's context and
1955 # see if we should stop. If so, remove the one-time sigil.
1957 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1959 # If the breakpoint is temporary, then delete its enabled status.
1960 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1961 _cancel_breakpoint_temp_enabled_status($filename, $line);
1964 } ## end if ($dbline{$line} && ...
1966 # Preserve the current stop-or-not, and see if any of the W
1967 # (watch expressions) has changed.
1968 my $was_signal = $signal;
1970 # If we have any watch expressions ...
1972 for ( my $n = 0 ; $n <= $#to_watch ; $n++ ) {
1973 $evalarg = $to_watch[$n];
1974 local $onetimeDump; # Tell DB::eval() to not output results
1976 # Fix context DB::eval() wants to return an array, but
1977 # we need a scalar here.
1978 my ($val) = join( "', '", &eval );
1979 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
1982 if ( $val ne $old_watch[$n] ) {
1984 # Yep! Show the difference, and fake an interrupt.
1987 Watchpoint $n:\t$to_watch[$n] changed:
1988 old value:\t$old_watch[$n]
1991 $old_watch[$n] = $val;
1992 } ## end if ($val ne $old_watch...
1993 } ## end for (my $n = 0 ; $n <= ...
1994 } ## end if ($trace & 2)
1996 =head2 C<watchfunction()>
1998 C<watchfunction()> is a function that can be defined by the user; it is a
1999 function which will be run on each entry to C<DB::DB>; it gets the
2000 current package, filename, and line as its parameters.
2002 The watchfunction can do anything it likes; it is executing in the
2003 debugger's context, so it has access to all of the debugger's internal
2004 data structures and functions.
2006 C<watchfunction()> can control the debugger's actions. Any of the following
2007 will cause the debugger to return control to the user's program after
2008 C<watchfunction()> executes:
2014 Returning a false value from the C<watchfunction()> itself.
2018 Altering C<$single> to a false value.
2022 Altering C<$signal> to a false value.
2026 Turning off the C<4> bit in C<$trace> (this also disables the
2027 check for C<watchfunction()>. This can be done with
2035 # If there's a user-defined DB::watchfunction, call it with the
2036 # current package, filename, and line. The function executes in
2038 if ( $trace & 4 ) { # User-installed watch
2040 if watchfunction( $package, $filename, $line )
2043 and not( $trace & ~4 );
2044 } ## end if ($trace & 4)
2046 # Pick up any alteration to $signal in the watchfunction, and
2047 # turn off the signal now.
2048 $was_signal = $signal;
2051 =head2 GETTING READY TO EXECUTE COMMANDS
2053 The debugger decides to take control if single-step mode is on, the
2054 C<t> command was entered, or the user generated a signal. If the program
2055 has fallen off the end, we set things up so that entering further commands
2056 won't cause trouble, and we say that the program is over.
2060 # Check to see if we should grab control ($single true,
2061 # trace set appropriately, or we got a signal).
2062 if ( $single || ( $trace & 1 ) || $was_signal ) {
2064 # Yes, grab control.
2065 if ($slave_editor) {
2067 # Tell the editor to update its position.
2068 $position = "\032\032$filename:$line:0\n";
2069 print_lineinfo($position);
2074 Special check: if we're in package C<DB::fake>, we've gone through the
2075 C<END> block at least once. We set up everything so that we can continue
2076 to enter commands and have a valid context to be in.
2080 elsif ( $package eq 'DB::fake' ) {
2082 # Fallen off the end already.
2085 Debugged program terminated. Use B<q> to quit or B<R> to restart,
2086 use B<o> I<inhibit_exit> to avoid stopping after program termination,
2087 B<h q>, B<h R> or B<h o> to get additional info.
2090 # Set the DB::eval context appropriately.
2093 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;'
2094 . "package $package;"; # this won't let them modify, alas
2095 } ## end elsif ($package eq 'DB::fake')
2099 If the program hasn't finished executing, we scan forward to the
2100 next executable line, print that out, build the prompt from the file and line
2101 number information, and print that.
2107 # Still somewhere in the midst of execution. Set up the
2109 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
2110 # Perl 5 ones (sorry, we don't print Klingon
2113 $prefix = $sub =~ /::/ ? "" : "${'package'}::";
2114 $prefix .= "$sub($filename:";
2115 $after = ( $dbline[$line] =~ /\n$/ ? '' : "\n" );
2117 # Break up the prompt if it's really long.
2118 if ( length($prefix) > 30 ) {
2119 $position = "$prefix$line):\n$line:\t$dbline[$line]$after";
2125 $position = "$prefix$line$infix$dbline[$line]$after";
2128 # Print current line info, indenting if necessary.
2130 print_lineinfo( ' ' x $stack_depth,
2131 "$line:\t$dbline[$line]$after" );
2134 depth_print_lineinfo($position);
2137 # Scan forward, stopping at either the end or the next
2139 for ( $i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i )
2142 # Drop out on null statements, block closers, and comments.
2143 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/;
2145 # Drop out if the user interrupted us.
2148 # Append a newline if the line doesn't have one. Can happen
2149 # in eval'ed text, for instance.
2150 $after = ( $dbline[$i] =~ /\n$/ ? '' : "\n" );
2152 # Next executable line.
2153 $incr_pos = "$prefix$i$infix$dbline[$i]$after";
2154 $position .= $incr_pos;
2157 # Print it indented if tracing is on.
2158 print_lineinfo( ' ' x $stack_depth,
2159 "$i:\t$dbline[$i]$after" );
2162 depth_print_lineinfo($incr_pos);
2164 } ## end for ($i = $line + 1 ; $i...
2165 } ## end else [ if ($slave_editor)
2166 } ## end if ($single || ($trace...
2170 If there's an action to be executed for the line we stopped at, execute it.
2171 If there are any preprompt actions, execute those as well.
2175 # If there's an action, do it now.
2176 $evalarg = $action, &eval if $action;
2178 # Are we nested another level (e.g., did we evaluate a function
2179 # that had a breakpoint in it at the debugger prompt)?
2180 if ( $single || $was_signal ) {
2182 # Yes, go down a level.
2183 local $level = $level + 1;
2185 # Do any pre-prompt actions.
2186 foreach $evalarg (@$pre) {
2190 # Complain about too much recursion if we passed the limit.
2191 print $OUT $stack_depth . " levels deep in subroutine calls!\n"
2194 # The line we're currently on. Set $incr to -1 to stay here
2195 # until we get a command that tells us to advance.
2197 $incr = -1; # for backward motion.
2199 # Tack preprompt debugger actions ahead of any actual input.
2200 @typeahead = ( @$pretype, @typeahead );
2202 =head2 WHERE ARE WE?
2204 XXX Relocate this section?
2206 The debugger normally shows the line corresponding to the current line of
2207 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2208 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2210 C<$incr> controls by how many lines the I<current> line should move forward
2211 after a command is executed. If set to -1, this indicates that the I<current>
2212 line shouldn't change.
2214 C<$start> is the I<current> line. It is used for things like knowing where to
2215 move forwards or backwards from when doing an C<L> or C<-> command.
2217 C<$max> tells the debugger where the last line of the current file is. It's
2218 used to terminate loops most often.
2220 =head2 THE COMMAND LOOP
2222 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2229 The outer part of the loop, starting at the C<CMD> label. This loop
2230 reads a command and then executes it.
2234 The inner part of the loop, starting at the C<PIPE> label. This part
2235 is wholly contained inside the C<CMD> block and only executes a command.
2236 Used to handle commands running inside a pager.
2240 So why have two labels to restart the loop? Because sometimes, it's easier to
2241 have a command I<generate> another command and then re-execute the loop to do
2242 the new command. This is faster, but perhaps a bit more convoluted.
2246 # The big command dispatch loop. It keeps running until the
2247 # user yields up control again.
2249 # If we have a terminal for input, and we get something back
2250 # from readline(), keep on processing.
2254 # We have a terminal, or can get one ...
2255 ( $term || &setterm ),
2257 # ... and it belogs to this PID or we get one for this PID ...
2258 ( $term_pid == $$ or resetterm(1) ),
2260 # ... and we got a line of command input ...
2263 "$pidprompt $tid DB"
2266 . ( '>' x $level ) . " "
2273 # ... try to execute the input as debugger commands.
2275 # Don't stop running.
2278 # No signal is active.
2281 # Handle continued commands (ending with \):
2282 $cmd =~ s/\\$/\n/ && do {
2283 $cmd .= &readline(" cont: ");
2287 =head4 The null command
2289 A newline entered by itself means I<re-execute the last command>. We grab the
2290 command out of C<$laststep> (where it was recorded previously), and copy it
2291 back into C<$cmd> to be executed below. If there wasn't any previous command,
2292 we'll do nothing below (no command will match). If there was, we also save it
2293 in the command history and fall through to allow the command parsing to pick
2298 # Empty input means repeat the last command.
2299 $cmd =~ /^$/ && ( $cmd = $laststep );
2300 chomp($cmd); # get rid of the annoying extra newline
2301 push( @hist, $cmd ) if length($cmd) > 1;
2302 push( @truehist, $cmd );
2306 # This is a restart point for commands that didn't arrive
2307 # via direct user input. It allows us to 'redo PIPE' to
2308 # re-execute command processing without reading a new command.
2310 $cmd =~ s/^\s+//s; # trim annoying leading whitespace
2311 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace
2312 ($i) = split( /\s+/, $cmd );
2314 =head3 COMMAND ALIASES
2316 The debugger can create aliases for commands (these are stored in the
2317 C<%alias> hash). Before a command is executed, the command loop looks it up
2318 in the alias hash and substitutes the contents of the alias for the command,
2319 completely replacing it.
2323 # See if there's an alias for the command, and set it up if so.
2326 # Squelch signal handling; we want to keep control here
2327 # if something goes loco during the alias eval.
2328 local $SIG{__DIE__};
2329 local $SIG{__WARN__};
2331 # This is a command, so we eval it in the DEBUGGER's
2332 # scope! Otherwise, we can't see the special debugger
2333 # variables, or get to the debugger's subs. (Well, we
2334 # _could_, but why make it even more complicated?)
2335 eval "\$cmd =~ $alias{$i}";
2338 print $OUT "Couldn't evaluate '$i' alias: $@";
2341 } ## end if ($alias{$i})
2343 =head3 MAIN-LINE COMMANDS
2345 All of these commands work up to and after the program being debugged has
2350 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2351 try to execute further, cleaning any restart-related stuff out of the
2352 environment, and executing with the last value of C<$?>.
2356 $cmd =~ /^q$/ && do {
2362 =head4 C<t> - trace [n]
2364 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2365 If level is specified, set C<$trace_to_depth>.
2369 $cmd =~ /^t(?:\s+(\d+))?$/ && do {
2373 $trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
2374 print $OUT "Trace = "
2376 ? ( $levels ? "on (to level $trace_to_depth)" : "on" )
2381 =head4 C<S> - list subroutines matching/not matching a pattern
2383 Walks through C<%sub>, checking to see whether or not to print the name.
2387 $cmd =~ /^S(\s+(!)?(.+))?$/ && do {
2389 $Srev = defined $2; # Reverse scan?
2390 $Spatt = $3; # The pattern (if any) to use.
2391 $Snocheck = !defined $1; # No args - print all subs.
2393 # Need to make these sane here.
2397 # Search through the debugger's magical hash of subs.
2398 # If $nocheck is true, just print the sub name.
2399 # Otherwise, check it against the pattern. We then use
2400 # the XOR trick to reverse the condition as required.
2401 foreach $subname ( sort( keys %sub ) ) {
2402 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2403 print $OUT $subname, "\n";
2409 =head4 C<X> - list variables in current package
2411 Since the C<V> command actually processes this, just change this to the
2412 appropriate C<V> command and fall through.
2416 $cmd =~ s/^X\b/V $package/;
2418 =head4 C<V> - list variables
2420 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2424 # Bare V commands get the currently-being-debugged package
2426 $cmd =~ /^V$/ && do {
2427 $cmd = "V $package";
2430 # V - show variables in package.
2431 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
2433 # Save the currently selected filehandle and
2434 # force output to debugger's filehandle (dumpvar
2435 # just does "print" for output).
2436 local ($savout) = select($OUT);
2438 # Grab package name and variables to dump.
2440 @vars = split( ' ', $2 );
2442 # If main::dumpvar isn't here, get it.
2443 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
2444 if ( defined &main::dumpvar ) {
2446 # We got it. Turn off subroutine entry/exit messages
2447 # for the moment, along with return values.
2451 # must detect sigpipe failures - not catching
2452 # then will cause the debugger to die.
2456 defined $option{dumpDepth}
2457 ? $option{dumpDepth}
2458 : -1, # assume -1 unless specified
2463 # The die doesn't need to include the $@, because
2464 # it will automatically get propagated for us.
2466 die unless $@ =~ /dumpvar print failed/;
2468 } ## end if (defined &main::dumpvar)
2471 # Couldn't load dumpvar.
2472 print $OUT "dumpvar.pl not available.\n";
2475 # Restore the output filehandle, and go round again.
2480 =head4 C<x> - evaluate and print an expression
2482 Hands the expression off to C<DB::eval>, setting it up to print the value
2483 via C<dumpvar.pl> instead of just printing it directly.
2487 $cmd =~ s/^x\b/ / && do { # Remainder gets done by DB::eval()
2488 $onetimeDump = 'dump'; # main::dumpvar shows the output
2490 # handle special "x 3 blah" syntax XXX propagate
2491 # doc back to special variables.
2492 if ( $cmd =~ s/^\s*(\d+)(?=\s)/ / ) {
2493 $onetimedumpDepth = $1;
2497 =head4 C<m> - print methods
2499 Just uses C<DB::methods> to determine what methods are available.
2503 $cmd =~ s/^m\s+([\w:]+)\s*$/ / && do {
2508 # m expr - set up DB::eval to do the work
2509 $cmd =~ s/^m\b/ / && do { # Rest gets done by DB::eval()
2510 $onetimeDump = 'methods'; # method output gets used there
2513 =head4 C<f> - switch files
2517 $cmd =~ /^f\b\s*(.*)/ && do {
2521 # help for no arguments (old-style was return from sub).
2524 "The old f command is now the r command.\n"; # hint
2525 print $OUT "The new f command switches filenames.\n";
2527 } ## end if (!$file)
2529 # if not in magic file list, try a close match.
2530 if ( !defined $main::{ '_<' . $file } ) {
2531 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2533 $try = substr( $try, 2 );
2534 print $OUT "Choosing $try matching '$file':\n";
2537 } ## end if (($try) = grep(m#^_<.*$file#...
2538 } ## end if (!defined $main::{ ...
2540 # If not successfully switched now, we failed.
2541 if ( !defined $main::{ '_<' . $file } ) {
2542 print $OUT "No file matching '$file' is loaded.\n";
2546 # We switched, so switch the debugger internals around.
2547 elsif ( $file ne $filename ) {
2548 *dbline = $main::{ '_<' . $file };
2553 } ## end elsif ($file ne $filename)
2555 # We didn't switch; say we didn't.
2557 print $OUT "Already in $file.\n";
2562 =head4 C<.> - return to last-executed line.
2564 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2565 and then we look up the line in the magical C<%dbline> hash.
2570 $cmd =~ /^\.$/ && do {
2571 $incr = -1; # stay at current line
2573 # Reset everything to the old location.
2575 $filename = $filename_ini;
2576 *dbline = $main::{ '_<' . $filename };
2580 print_lineinfo($position);
2584 =head4 C<-> - back one window
2586 We change C<$start> to be one window back; if we go back past the first line,
2587 we set it to be the first line. We ser C<$incr> to put us back at the
2588 currently-executing line, and then put a C<l $start +> (list one window from
2589 C<$start>) in C<$cmd> to be executed later.
2593 # - - back a window.
2594 $cmd =~ /^-$/ && do {
2596 # back up by a window; go to 1 if back too far.
2597 $start -= $incr + $window + 1;
2598 $start = 1 if $start <= 0;
2599 $incr = $window - 1;
2601 # Generate and execute a "l +" command (handled below).
2602 $cmd = 'l ' . ($start) . '+';
2605 =head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, {, {{>
2607 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2608 problems, most notably that the default case of several commands destroying
2609 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2610 retain the old commands for those who were used to using them or who preferred
2611 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2612 deal with them instead of processing them in-line.
2616 # All of these commands were remapped in perl 5.8.0;
2617 # we send them off to the secondary dispatcher (see below).
2618 $cmd =~ /^([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so && do {
2619 &cmd_wrapper( $1, $2, $line );
2623 =head4 C<y> - List lexicals in higher scope
2625 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2626 above the current one and then displays then using C<dumpvar.pl>.
2630 $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/ && do {
2632 # See if we've got the necessary support.
2633 eval { require PadWalker; PadWalker->VERSION(0.08) }
2636 ? "PadWalker module not found - please install\n"
2641 # Load up dumpvar if we don't have it. If we can, that is.
2642 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
2643 defined &main::dumpvar
2644 or print $OUT "dumpvar.pl not available.\n"
2647 # Got all the modules we need. Find them and print them.
2648 my @vars = split( ' ', $2 || '' );
2651 my $h = eval { PadWalker::peek_my( ( $1 || 0 ) + 1 ) };
2653 # Oops. Can't find it.
2654 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2656 # Show the desired vars with dumplex().
2657 my $savout = select($OUT);
2659 # Have dumplex dump the lexicals.
2660 dumpvar::dumplex( $_, $h->{$_},
2661 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
2668 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2670 All of the commands below this point don't work after the program being
2671 debugged has ended. All of them check to see if the program has ended; this
2672 allows the commands to be relocated without worrying about a 'line of
2673 demarcation' above which commands can be entered anytime, and below which
2676 =head4 C<n> - single step, but don't trace down into subs
2678 Done by setting C<$single> to 2, which forces subs to execute straight through
2679 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2680 so a null command knows what to re-execute.
2685 $cmd =~ /^n$/ && do {
2686 end_report(), next CMD if $finished and $level <= 1;
2688 # Single step, but don't enter subs.
2691 # Save for empty command (repeat last).
2696 =head4 C<s> - single-step, entering subs
2698 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2699 subs. Also saves C<s> as C<$lastcmd>.
2704 $cmd =~ /^s$/ && do {
2706 # Get out and restart the command loop if program
2708 end_report(), next CMD if $finished and $level <= 1;
2710 # Single step should enter subs.
2713 # Save for empty command (repeat last).
2718 =head4 C<c> - run continuously, setting an optional breakpoint
2720 Most of the code for this command is taken up with locating the optional
2721 breakpoint, which is either a subroutine name or a line number. We set
2722 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2723 in this and all call levels above this one.
2727 # c - start continuous execution.
2728 $cmd =~ /^c\b\s*([\w:]*)\s*$/ && do {
2730 # Hey, show's over. The debugged program finished
2731 # executing already.
2732 end_report(), next CMD if $finished and $level <= 1;
2734 # Capture the place to put a one-time break.
2737 # Probably not needed, since we finish an interactive
2738 # sub-session anyway...
2739 # local $filename = $filename;
2740 # local *dbline = *dbline; # XXX Would this work?!
2742 # The above question wonders if localizing the alias
2743 # to the magic array works or not. Since it's commented
2744 # out, we'll just leave that to speculation for now.
2746 # If the "subname" isn't all digits, we'll assume it
2747 # is a subroutine name, and try to find it.
2748 if ( $subname =~ /\D/ ) { # subroutine name
2749 # Qualify it to the current package unless it's
2750 # already qualified.
2751 $subname = $package . "::" . $subname
2752 unless $subname =~ /::/;
2754 # find_sub will return "file:line_number" corresponding
2755 # to where the subroutine is defined; we call find_sub,
2756 # break up the return value, and assign it in one
2758 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2760 # Force the line number to be numeric.
2763 # If we got a line number, we found the sub.
2766 # Switch all the debugger's internals around so
2767 # we're actually working with that file.
2769 *dbline = $main::{ '_<' . $filename };
2771 # Mark that there's a breakpoint in this file.
2772 $had_breakpoints{$filename} |= 1;
2774 # Scan forward to the first executable line
2775 # after the 'sub whatever' line.
2777 ++$i while $dbline[$i] == 0 && $i < $max;
2780 # We didn't find a sub by that name.
2782 print $OUT "Subroutine $subname not found.\n";
2785 } ## end if ($subname =~ /\D/)
2787 # At this point, either the subname was all digits (an
2788 # absolute line-break request) or we've scanned through
2789 # the code following the definition of the sub, looking
2790 # for an executable, which we may or may not have found.
2792 # If $i (which we set $subname from) is non-zero, we
2793 # got a request to break at some line somewhere. On
2794 # one hand, if there wasn't any real subroutine name
2795 # involved, this will be a request to break in the current
2796 # file at the specified line, so we have to check to make
2797 # sure that the line specified really is breakable.
2799 # On the other hand, if there was a subname supplied, the
2800 # preceding block has moved us to the proper file and
2801 # location within that file, and then scanned forward
2802 # looking for the next executable line. We have to make
2803 # sure that one was found.
2805 # On the gripping hand, we can't do anything unless the
2806 # current value of $i points to a valid breakable line.
2811 if ( $dbline[$i] == 0 ) {
2812 print $OUT "Line $i not breakable.\n";
2816 # Yes. Set up the one-time-break sigil.
2817 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2818 _enable_breakpoint_temp_enabled_status($filename, $i);
2821 # Turn off stack tracing from here up.
2822 for ( $i = 0 ; $i <= $stack_depth ; ) {
2823 $stack[ $i++ ] &= ~1;
2828 =head4 C<r> - return from a subroutine
2830 For C<r> to work properly, the debugger has to stop execution again
2831 immediately after the return is executed. This is done by forcing
2832 single-stepping to be on in the call level above the current one. If
2833 we are printing return values when a C<r> is executed, set C<$doret>
2834 appropriately, and force us out of the command loop.
2838 # r - return from the current subroutine.
2839 $cmd =~ /^r$/ && do {
2841 # Can't do anything if the program's over.
2842 end_report(), next CMD if $finished and $level <= 1;
2844 # Turn on stack trace.
2845 $stack[$stack_depth] |= 1;
2847 # Print return value unless the stack is empty.
2848 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2852 =head4 C<T> - stack trace
2854 Just calls C<DB::print_trace>.
2858 $cmd =~ /^T$/ && do {
2859 print_trace( $OUT, 1 ); # skip DB
2863 =head4 C<w> - List window around current line.
2865 Just calls C<DB::cmd_w>.
2869 $cmd =~ /^w\b\s*(.*)/s && do { &cmd_w( 'w', $1 ); next CMD; };
2871 =head4 C<W> - watch-expression processing.
2873 Just calls C<DB::cmd_W>.
2877 $cmd =~ /^W\b\s*(.*)/s && do { &cmd_W( 'W', $1 ); next CMD; };
2879 =head4 C</> - search forward for a string in the source
2881 We take the argument and treat it as a pattern. If it turns out to be a
2882 bad one, we return the error we got from trying to C<eval> it and exit.
2883 If not, we create some code to do the search and C<eval> it so it can't
2888 $cmd =~ /^\/(.*)$/ && do {
2890 # The pattern as a string.
2893 # Remove the final slash.
2894 $inpat =~ s:([^\\])/$:$1:;
2896 # If the pattern isn't null ...
2897 if ( $inpat ne "" ) {
2899 # Turn of warn and die procesing for a bit.
2900 local $SIG{__DIE__};
2901 local $SIG{__WARN__};
2903 # Create the pattern.
2904 eval '$inpat =~ m' . "\a$inpat\a";
2907 # Oops. Bad pattern. No biscuit.
2908 # Print the eval error and go back for more
2914 } ## end if ($inpat ne "")
2916 # Set up to stop on wrap-around.
2919 # Don't move off the current line.
2922 # Done in eval so nothing breaks if the pattern
2923 # does something weird.
2926 # Move ahead one line.
2929 # Wrap if we pass the last line.
2930 $start = 1 if ($start > $max);
2932 # Stop if we have gotten back to this line again,
2933 last if ($start == $end);
2935 # A hit! (Note, though, that we are doing
2936 # case-insensitive matching. Maybe a qr//
2937 # expression would be better, so the user could
2938 # do case-sensitive matching if desired.
2939 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2940 if ($slave_editor) {
2941 # Handle proper escaping in the slave.
2942 print $OUT "\032\032$filename:$start:0\n";
2945 # Just print the line normally.
2946 print $OUT "$start:\t",$dbline[$start],"\n";
2948 # And quit since we found something.
2953 # If we wrapped, there never was a match.
2954 print $OUT "/$pat/: not found\n" if ( $start == $end );
2958 =head4 C<?> - search backward for a string in the source
2960 Same as for C</>, except the loop runs backwards.
2964 # ? - backward pattern search.
2965 $cmd =~ /^\?(.*)$/ && do {
2967 # Get the pattern, remove trailing question mark.
2969 $inpat =~ s:([^\\])\?$:$1:;
2971 # If we've got one ...
2972 if ( $inpat ne "" ) {
2974 # Turn off die & warn handlers.
2975 local $SIG{__DIE__};
2976 local $SIG{__WARN__};
2977 eval '$inpat =~ m' . "\a$inpat\a";
2981 # Ouch. Not good. Print the error.
2986 } ## end if ($inpat ne "")
2988 # Where we are now is where to stop after wraparound.
2991 # Don't move away from this line.
2994 # Search inside the eval to prevent pattern badness
3001 # Wrap if we pass the first line.
3003 $start = $max if ($start <= 0);
3005 # Quit if we get back where we started,
3006 last if ($start == $end);
3009 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
3010 if ($slave_editor) {
3011 # Yep, follow slave editor requirements.
3012 print $OUT "\032\032$filename:$start:0\n";
3015 # Yep, just print normally.
3016 print $OUT "$start:\t",$dbline[$start],"\n";
3024 # Say we failed if the loop never found anything,
3025 print $OUT "?$pat?: not found\n" if ( $start == $end );
3029 =head4 C<$rc> - Recall command
3031 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
3032 that the terminal supports history). It find the the command required, puts it
3033 into C<$cmd>, and redoes the loop to execute it.
3037 # $rc - recall command.
3038 $cmd =~ /^$rc+\s*(-)?(\d+)?$/ && do {
3040 # No arguments, take one thing off history.
3041 pop(@hist) if length($cmd) > 1;
3043 # Relative (- found)?
3044 # Y - index back from most recent (by 1 if bare minus)
3045 # N - go to that particular command slot or the last
3046 # thing if nothing following.
3047 $i = $1 ? ( $#hist - ( $2 || 1 ) ) : ( $2 || $#hist );
3049 # Pick out the command desired.
3052 # Print the command to be executed and restart the loop
3053 # with that command in the buffer.
3054 print $OUT $cmd, "\n";
3058 =head4 C<$sh$sh> - C<system()> command
3060 Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
3061 C<STDOUT> from getting messed up.
3065 # $sh$sh - run a shell command (if it's all ASCII).
3066 # Can't run shell commands with Unicode in the debugger, hmm.
3067 $cmd =~ /^$sh$sh\s*([\x00-\xff]*)/ && do {
3074 =head4 C<$rc I<pattern> $rc> - Search command history
3076 Another command to manipulate C<@hist>: this one searches it with a pattern.
3077 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
3081 # $rc pattern $rc - find a command in the history.
3082 $cmd =~ /^$rc([^$rc].*)$/ && do {
3084 # Create the pattern to use.
3087 # Toss off last entry if length is >1 (and it always is).
3088 pop(@hist) if length($cmd) > 1;
3090 # Look backward through the history.
3091 for ( $i = $#hist ; $i ; --$i ) {
3093 # Stop if we find it.
3094 last if $hist[$i] =~ /$pat/;
3100 print $OUT "No such command!\n\n";
3104 # Found it. Put it in the buffer, print it, and process it.
3106 print $OUT $cmd, "\n";
3110 =head4 C<$sh> - Invoke a shell
3112 Uses C<DB::system> to invoke a shell.
3116 # $sh - start a shell.
3117 $cmd =~ /^$sh$/ && do {
3119 # Run the user's shell. If none defined, run Bourne.
3120 # We resume execution when the shell terminates.
3121 &system( $ENV{SHELL} || "/bin/sh" );
3125 =head4 C<$sh I<command>> - Force execution of a command in a shell
3127 Like the above, but the command is passed to the shell. Again, we use
3128 C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
3132 # $sh command - start a shell and run a command in it.
3133 $cmd =~ /^$sh\s*([\x00-\xff]*)/ && do {
3135 # XXX: using csh or tcsh destroys sigint retvals!
3136 #&system($1); # use this instead
3138 # use the user's shell, or Bourne if none defined.
3139 &system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3143 =head4 C<H> - display commands in history
3145 Prints the contents of C<@hist> (if any).
3149 $cmd =~ /^H\b\s*\*/ && do {
3150 @hist = @truehist = ();
3151 print $OUT "History cleansed\n";
3155 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
3157 # Anything other than negative numbers is ignored by
3158 # the (incorrect) pattern, so this test does nothing.
3159 $end = $2 ? ( $#hist - $2 ) : 0;
3161 # Set to the minimum if less than zero.
3162 $hist = 0 if $hist < 0;
3164 # Start at the end of the array.
3165 # Stay in while we're still above the ending value.
3166 # Tick back by one each time around the loop.
3167 for ( $i = $#hist ; $i > $end ; $i-- ) {
3169 # Print the command unless it has no arguments.
3170 print $OUT "$i: ", $hist[$i], "\n"
3171 unless $hist[$i] =~ /^.?$/;
3176 =head4 C<man, doc, perldoc> - look up documentation
3178 Just calls C<runman()> to print the appropriate document.
3182 # man, perldoc, doc - show manual pages.
3183 $cmd =~ /^(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?$/ && do {
3190 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3191 the bottom of the loop.
3195 # p - print (no args): print $_.
3196 $cmd =~ s/^p$/print {\$DB::OUT} \$_/;
3198 # p - print the given expression.
3199 $cmd =~ s/^p\b/print {\$DB::OUT} /;
3201 =head4 C<=> - define command alias
3203 Manipulates C<%alias> to add or list command aliases.
3207 # = - set up a command alias.
3208 $cmd =~ s/^=\s*// && do {
3210 if ( length $cmd == 0 ) {
3212 # No args, get current aliases.
3213 @keys = sort keys %alias;
3215 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3217 # Creating a new alias. $k is alias name, $v is
3220 # can't use $_ or kill //g state
3221 for my $x ( $k, $v ) {
3223 # Escape "alarm" characters.
3227 # Substitute key for value, using alarm chars
3228 # as separators (which is why we escaped them in
3230 $alias{$k} = "s\a$k\a$v\a";
3232 # Turn off standard warn and die behavior.
3233 local $SIG{__DIE__};
3234 local $SIG{__WARN__};
3237 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3239 # Nope. Bad alias. Say so and get out.
3240 print $OUT "Can't alias $k to $v: $@\n";
3245 # We'll only list the new one.
3247 } ## end elsif (my ($k, $v) = ($cmd...
3249 # The argument is the alias to list.
3257 # Messy metaquoting: Trim the substitution code off.
3258 # We use control-G as the delimiter because it's not
3259 # likely to appear in the alias.
3260 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3263 print $OUT "$k\t= $1\n";
3265 elsif ( defined $alias{$k} ) {
3267 # Couldn't trim it off; just print the alias code.
3268 print $OUT "$k\t$alias{$k}\n";
3273 print "No alias for $k\n";
3275 } ## end for my $k (@keys)
3279 =head4 C<source> - read commands from a file.
3281 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3286 # source - read commands from a file (or pipe!) and execute.
3287 $cmd =~ /^source\s+(.*\S)/ && do {
3288 if ( open my $fh, $1 ) {
3290 # Opened OK; stick it in the list of file handles.
3296 &warn("Can't execute '$1': $!\n");
3301 $cmd =~ /^(enable|disable)\s+(\S+)\s*$/ && do {
3302 my ($cmd, $position) = ($1, $2);
3304 my ($fn, $line_num);
3305 if ($position =~ m{\A\d+\z})
3308 $line_num = $position;
3310 elsif ($position =~ m{\A(.*):(\d+)\z})
3312 ($fn, $line_num) = ($1, $2);
3316 &warn("Wrong spec for enable/disable argument.\n");
3320 if (_has_breakpoint_data_ref($fn, $line_num)) {
3321 _set_breakpoint_enabled_status($fn, $line_num,
3322 ($cmd eq 'enable' ? 1 : '')
3326 &warn("No breakpoint set at ${fn}:${line_num}\n");
3333 =head4 C<save> - send current history to a file
3335 Takes the complete history, (not the shrunken version you see with C<H>),
3336 and saves it to the given filename, so it can be replayed using C<source>.
3338 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3342 # save source - write commands to a file for later use
3343 $cmd =~ /^save\s*(.*)$/ && do {
3344 my $file = $1 || '.perl5dbrc'; # default?
3345 if ( open my $fh, "> $file" ) {
3347 # chomp to remove extraneous newlines from source'd files
3348 chomp( my @truelist =
3349 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3351 print $fh join( "\n", @truelist );
3352 print "commands saved in $file\n";
3355 &warn("Can't save debugger commands in '$1': $!\n");
3360 =head4 C<R> - restart
3362 Restart the debugger session.
3364 =head4 C<rerun> - rerun the current session
3366 Return to any given position in the B<true>-history list
3370 # R - restart execution.
3371 # rerun - controlled restart execution.
3372 $cmd =~ /^(R|rerun\s*(.*))$/ && do {
3373 my @args = ($1 eq 'R' ? restart() : rerun($2));
3375 # Close all non-system fds for a clean restart. A more
3376 # correct method would be to close all fds that were not
3377 # open when the process started, but this seems to be
3378 # hard. See "debugger 'R'estart and open database
3379 # connections" on p5p.
3381 my $max_fd = 1024; # default if POSIX can't be loaded
3382 if (eval { require POSIX }) {
3383 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
3386 if (defined $max_fd) {
3387 foreach ($^F+1 .. $max_fd-1) {
3388 next unless open FD_TO_CLOSE, "<&=$_";
3393 # And run Perl again. We use exec() to keep the
3394 # PID stable (and that way $ini_pids is still valid).
3395 exec(@args) || print $OUT "exec failed: $!\n";
3400 =head4 C<|, ||> - pipe output through the pager.
3402 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3403 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3404 pipe to the pager (restoring the output filehandles if this fails). If this
3405 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3406 set C<$signal>, sending us back into the debugger.
3408 We then trim off the pipe symbols and C<redo> the command loop at the
3409 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3414 # || - run command in the pager, with output to DB::OUT.
3415 $cmd =~ /^\|\|?\s*[^|]/ && do {
3416 if ( $pager =~ /^\|/ ) {
3418 # Default pager is into a pipe. Redirect I/O.
3419 open( SAVEOUT, ">&STDOUT" )
3420 || &warn("Can't save STDOUT");
3421 open( STDOUT, ">&OUT" )
3422 || &warn("Can't redirect STDOUT");
3423 } ## end if ($pager =~ /^\|/)
3426 # Not into a pipe. STDOUT is safe.
3427 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3430 # Fix up environment to record we have less if so.
3433 unless ( $piped = open( OUT, $pager ) ) {
3435 # Couldn't open pipe to pager.
3436 &warn("Can't pipe output to '$pager'");
3437 if ( $pager =~ /^\|/ ) {
3439 # Redirect I/O back again.
3440 open( OUT, ">&STDOUT" ) # XXX: lost message
3441 || &warn("Can't restore DB::OUT");
3442 open( STDOUT, ">&SAVEOUT" )
3443 || &warn("Can't restore STDOUT");
3445 } ## end if ($pager =~ /^\|/)
3448 # Redirect I/O. STDOUT already safe.
3449 open( OUT, ">&STDOUT" ) # XXX: lost message
3450 || &warn("Can't restore DB::OUT");
3453 } ## end unless ($piped = open(OUT,...
3455 # Set up broken-pipe handler if necessary.
3456 $SIG{PIPE} = \&DB::catch
3458 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
3460 # Save current filehandle, unbuffer out, and put it back.
3461 $selected = select(OUT);
3464 # Don't put it back if pager was a pipe.
3465 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
3467 # Trim off the pipe symbols and run the command now.
3468 $cmd =~ s/^\|+\s*//;
3472 =head3 END OF COMMAND PARSING
3474 Anything left in C<$cmd> at this point is a Perl expression that we want to
3475 evaluate. We'll always evaluate in the user's context, and fully qualify
3476 any variables we might want to address in the C<DB> package.
3480 # t - turn trace on.
3481 $cmd =~ s/^t\s+(\d+)?/\$DB::trace |= 1;\n/ && do {
3482 $trace_to_depth = $1 ? $stack_depth||0 + $1 : 1E9;
3485 # s - single-step. Remember the last command was 's'.
3486 $cmd =~ s/^s\s/\$DB::single = 1;\n/ && do { $laststep = 's' };
3488 # n - single-step, but not into subs. Remember last command
3490 $cmd =~ s/^n\s/\$DB::single = 2;\n/ && do { $laststep = 'n' };
3494 # Make sure the flag that says "the debugger's running" is
3495 # still on, to make sure we get control again.
3496 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3498 # Run *our* eval that executes in the caller's context.
3501 # Turn off the one-time-dump stuff now.
3503 $onetimeDump = undef;
3504 $onetimedumpDepth = undef;
3506 elsif ( $term_pid == $$ ) {
3507 eval { # May run under miniperl, when not available...
3512 # XXX If this is the master pid, print a newline.
3515 } ## end while (($term || &setterm...
3517 =head3 POST-COMMAND PROCESSING
3519 After each command, we check to see if the command output was piped anywhere.
3520 If so, we go through the necessary code to unhook the pipe and go back to
3521 our standard filehandles for input and output.
3527 # At the end of every command:
3530 # Unhook the pipe mechanism now.
3531 if ( $pager =~ /^\|/ ) {
3533 # No error from the child.
3536 # we cannot warn here: the handle is missing --tchrist
3537 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
3539 # most of the $? crud was coping with broken cshisms
3540 # $? is explicitly set to 0, so this never runs.
3542 print SAVEOUT "Pager '$pager' failed: ";
3544 print SAVEOUT "shell returned -1\n";
3547 print SAVEOUT ( $? & 127 )
3548 ? " (SIG#" . ( $? & 127 ) . ")"
3549 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3552 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3556 # Reopen filehandle for our output (if we can) and
3557 # restore STDOUT (if we can).
3558 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3559 open( STDOUT, ">&SAVEOUT" )
3560 || &warn("Can't restore STDOUT");
3562 # Turn off pipe exception handler if necessary.
3563 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
3565 # Will stop ignoring SIGPIPE if done like nohup(1)
3566 # does SIGINT but Perl doesn't give us a choice.
3567 } ## end if ($pager =~ /^\|/)
3570 # Non-piped "pager". Just restore STDOUT.
3571 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3574 # Close filehandle pager was using, restore the normal one
3577 select($selected), $selected = "" unless $selected eq "";
3581 } ## end if ($piped)
3584 =head3 COMMAND LOOP TERMINATION
3586 When commands have finished executing, we come here. If the user closed the
3587 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3588 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3589 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3590 The interpreter will then execute the next line and then return control to us
3595 # No more commands? Quit.
3596 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
3598 # Evaluate post-prompt commands.
3599 foreach $evalarg (@$post) {
3602 } # if ($single || $signal)
3604 # Put the user's globals back where you found them.
3605 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3609 # The following code may be executed now:
3614 C<sub> is called whenever a subroutine call happens in the program being
3615 debugged. The variable C<$DB::sub> contains the name of the subroutine
3618 The core function of this subroutine is to actually call the sub in the proper
3619 context, capturing its output. This of course causes C<DB::DB> to get called
3620 again, repeating until the subroutine ends and returns control to C<DB::sub>
3621 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3622 return value, and returns its captured copy of the return value as its own
3623 return value. The value then feeds back into the program being debugged as if
3624 C<DB::sub> hadn't been there at all.
3626 C<sub> does all the work of printing the subroutine entry and exit messages
3627 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3628 and also prints the return value if needed (for the C<r> command and if
3629 the 16 bit is set in C<$frame>).
3631 It also tracks the subroutine call depth by saving the current setting of
3632 C<$single> in the C<@stack> package global; if this exceeds the value in
3633 C<$deep>, C<sub> automatically turns on printing of the current depth by
3634 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
3635 of stop/don't stop on entry to subs set as it currently is set.
3637 =head3 C<caller()> support
3639 If C<caller()> is called from the package C<DB>, it provides some
3640 additional data, in the following order:
3646 The package name the sub was in
3648 =item * C<$filename>
3650 The filename it was defined in
3654 The line number it was defined on
3656 =item * C<$subroutine>
3658 The subroutine name; C<(eval)> if an C<eval>().
3662 1 if it has arguments, 0 if not
3664 =item * C<$wantarray>
3666 1 if array context, 0 if scalar context
3668 =item * C<$evaltext>
3670 The C<eval>() text, if any (undefined for C<eval BLOCK>)
3672 =item * C<$is_require>
3674 frame was created by a C<use> or C<require> statement
3678 pragma information; subject to change between versions
3682 pragma information; subject to change between versions
3684 =item * C<@DB::args>
3686 arguments with which the subroutine was invoked
3693 # Do not use a regex in this subroutine -> results in corrupted memory
3694 # See: [perl #66110]
3696 # lock ourselves under threads
3699 # Whether or not the autoloader was running, a scalar to put the
3700 # sub's return value in (if needed), and an array to put the sub's
3701 # return value in (if needed).
3702 my ( $al, $ret, @ret ) = "";
3703 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) {
3704 print "creating new thread\n";
3707 # If the last ten characters are '::AUTOLOAD', note we've traced
3708 # into AUTOLOAD for $sub.
3709 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3710 $al = " for $$sub" if defined $$sub;
3713 # We stack the stack pointer and then increment it to protect us
3714 # from a situation that might unwind a whole bunch of call frames
3715 # at once. Localizing the stack pointer means that it will automatically
3716 # unwind the same amount when multiple stack frames are unwound.
3717 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3720 $#stack = $stack_depth;
3722 # Save current single-step setting.
3723 $stack[-1] = $single;
3725 # Turn off all flags except single-stepping.
3728 # If we've gotten really deeply recursed, turn on the flag that will
3729 # make us stop with the 'deep recursion' message.
3730 $single |= 4 if $stack_depth == $deep;
3732 # If frame messages are on ...
3734 $frame & 4 # Extended frame entry message
3736 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3738 # Why -1? But it works! :-(
3739 # Because print_trace will call add 1 to it and then call
3740 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3742 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3744 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3746 # standard frame entry message
3750 # Determine the sub's return type, and capture appropriately.
3753 # Called in array context. call sub and capture output.
3754 # DB::DB will recursively get control again if appropriate; we'll come
3755 # back here when the sub is finished.
3758 # Pop the single-step value back off the stack.
3759 $single |= $stack[ $stack_depth-- ];
3761 # Check for exit trace messages...
3763 $frame & 4 # Extended exit message
3765 print_lineinfo( ' ' x $stack_depth, "out " ),
3766 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3768 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3770 # Standard exit message
3774 # Print the return info if we need to.
3775 if ( $doret eq $stack_depth or $frame & 16 ) {
3777 # Turn off output record separator.
3779 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3781 # Indent if we're printing because of $frame tracing.
3782 print $fh ' ' x $stack_depth if $frame & 16;
3784 # Print the return value.
3785 print $fh "list context return from $sub:\n";
3786 dumpit( $fh, \@ret );
3788 # And don't print it again.
3790 } ## end if ($doret eq $stack_depth...
3791 # And we have to return the return value now.
3793 } ## end if (wantarray)
3797 if ( defined wantarray ) {
3799 # Save the value if it's wanted at all.
3804 # Void return, explicitly.
3809 # Pop the single-step value off the stack.
3810 $single |= $stack[ $stack_depth-- ];
3812 # If we're doing exit messages...
3814 $frame & 4 # Extended messages
3816 print_lineinfo( ' ' x $stack_depth, "out " ),
3817 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3819 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3825 # If we are supposed to show the return value... same as before.
3826 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
3828 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3829 print $fh ( ' ' x $stack_depth ) if $frame & 16;
3832 ? "scalar context return from $sub: "
3833 : "void context return from $sub\n"
3835 dumpit( $fh, $ret ) if defined wantarray;
3837 } ## end if ($doret eq $stack_depth...
3839 # Return the appropriate scalar value.
3841 } ## end else [ if (wantarray)
3846 # lock ourselves under threads
3849 # Whether or not the autoloader was running, a scalar to put the
3850 # sub's return value in (if needed), and an array to put the sub's
3851 # return value in (if needed).
3852 my ( $al, $ret, @ret ) = "";
3853 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
3854 print "creating new thread\n";
3857 # If the last ten characters are C'::AUTOLOAD', note we've traced
3858 # into AUTOLOAD for $sub.
3859 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3863 # We stack the stack pointer and then increment it to protect us
3864 # from a situation that might unwind a whole bunch of call frames
3865 # at once. Localizing the stack pointer means that it will automatically
3866 # unwind the same amount when multiple stack frames are unwound.
3867 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3870 $#stack = $stack_depth;
3872 # Save current single-step setting.
3873 $stack[-1] = $single;
3875 # Turn off all flags except single-stepping.
3878 # If we've gotten really deeply recursed, turn on the flag that will
3879 # make us stop with the 'deep recursion' message.
3880 $single |= 4 if $stack_depth == $deep;
3882 # If frame messages are on ...
3884 $frame & 4 # Extended frame entry message
3886 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3888 # Why -1? But it works! :-(
3889 # Because print_trace will call add 1 to it and then call
3890 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3892 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3894 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3896 # standard frame entry message
3900 # Pop the single-step value back off the stack.
3901 $single |= $stack[ $stack_depth-- ];
3903 # call the original lvalue sub.
3907 # Abstracting common code from multiple places elsewhere:
3908 sub depth_print_lineinfo {
3909 print_lineinfo( @_ ) if $stack_depth < $trace_to_depth;
3912 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
3914 In Perl 5.8.0, there was a major realignment of the commands and what they did,
3915 Most of the changes were to systematize the command structure and to eliminate
3916 commands that threw away user input without checking.
3918 The following sections describe the code added to make it easy to support
3919 multiple command sets with conflicting command names. This section is a start
3920 at unifying all command processing to make it simpler to develop commands.
3922 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
3923 number, and C<$dbline> (the current line) as arguments.
3925 Support functions in this section which have multiple modes of failure C<die>
3926 on error; the rest simply return a false value.
3928 The user-interface functions (all of the C<cmd_*> functions) just output
3933 The C<%set> hash defines the mapping from command letter to subroutine
3936 C<%set> is a two-level hash, indexed by set name and then by command name.
3937 Note that trying to set the CommandSet to C<foobar> simply results in the
3938 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
3947 'A' => 'pre580_null',
3949 'B' => 'pre580_null',
3950 'd' => 'pre580_null',
3953 'M' => 'pre580_null',
3955 'o' => 'pre580_null',
3961 '<' => 'pre590_prepost',
3962 '<<' => 'pre590_prepost',
3963 '>' => 'pre590_prepost',
3964 '>>' => 'pre590_prepost',
3965 '{' => 'pre590_prepost',
3966 '{{' => 'pre590_prepost',
3970 my %breakpoints_data;
3972 sub _has_breakpoint_data_ref {
3973 my ($filename, $line) = @_;
3976 exists( $breakpoints_data{$filename} )
3978 exists( $breakpoints_data{$filename}{$line} )
3982 sub _get_breakpoint_data_ref {
3983 my ($filename, $line) = @_;
3985 return ($breakpoints_data{$filename}{$line} ||= +{});
3988 sub _delete_breakpoint_data_ref {
3989 my ($filename, $line) = @_;
3991 delete($breakpoints_data{$filename}{$line});
3992 if (! scalar(keys( %{$breakpoints_data{$filename}} )) ) {
3993 delete($breakpoints_data{$filename});
3999 sub _set_breakpoint_enabled_status {
4000 my ($filename, $line, $status) = @_;
4002 _get_breakpoint_data_ref($filename, $line)->{'enabled'} =
4009 sub _enable_breakpoint_temp_enabled_status {
4010 my ($filename, $line) = @_;
4012 _get_breakpoint_data_ref($filename, $line)->{'temp_enabled'} = 1;
4017 sub _cancel_breakpoint_temp_enabled_status {
4018 my ($filename, $line) = @_;
4020 my $ref = _get_breakpoint_data_ref($filename, $line);
4022 delete ($ref->{'temp_enabled'});
4025 _delete_breakpoint_data_ref($filename, $line);
4031 sub _is_breakpoint_enabled {
4032 my ($filename, $line) = @_;
4034 my $data_ref = _get_breakpoint_data_ref($filename, $line);
4035 return ($data_ref->{'enabled'} || $data_ref->{'temp_enabled'});
4038 =head2 C<cmd_wrapper()> (API)
4040 C<cmd_wrapper()> allows the debugger to switch command sets
4041 depending on the value of the C<CommandSet> option.
4043 It tries to look up the command in the C<%set> package-level I<lexical>
4044 (which means external entities can't fiddle with it) and create the name of
4045 the sub to call based on the value found in the hash (if it's there). I<All>
4046 of the commands to be handled in a set have to be added to C<%set>; if they
4047 aren't found, the 5.8.0 equivalent is called (if there is one).
4049 This code uses symbolic references.
4056 my $dblineno = shift;
4058 # Assemble the command subroutine's name by looking up the
4059 # command set and command name in %set. If we can't find it,
4060 # default to the older version of the command.
4062 . ( $set{$CommandSet}{$cmd}
4063 || ( $cmd =~ /^[<>{]+/o ? 'prepost' : $cmd ) );
4065 # Call the command subroutine, call it by name.
4066 return &$call( $cmd, $line, $dblineno );
4067 } ## end sub cmd_wrapper
4069 =head3 C<cmd_a> (command)
4071 The C<a> command handles pre-execution actions. These are associated with a
4072 particular line, so they're stored in C<%dbline>. We default to the current
4073 line if none is specified.
4079 my $line = shift || ''; # [.|line] expr
4082 # If it's dot (here), or not all digits, use the current line.
4083 $line =~ s/^(\.|(?:[^\d]))/$dbline/;
4085 # Should be a line number followed by an expression.
4086 if ( $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
4087 my ( $lineno, $expr ) = ( $1, $2 );
4089 # If we have an expression ...
4090 if ( length $expr ) {
4092 # ... but the line isn't breakable, complain.
4093 if ( $dbline[$lineno] == 0 ) {
4095 "Line $lineno($dbline[$lineno]) does not have an action?\n";
4099 # It's executable. Record that the line has an action.
4100 $had_breakpoints{$filename} |= 2;
4102 # Remove any action, temp breakpoint, etc.
4103 $dbline{$lineno} =~ s/\0[^\0]*//;
4105 # Add the action to the line.
4106 $dbline{$lineno} .= "\0" . action($expr);
4108 } ## end if (length $expr)
4109 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
4114 "Adding an action requires an optional lineno and an expression\n"
4119 =head3 C<cmd_A> (command)
4121 Delete actions. Similar to above, except the delete code is in a separate
4122 subroutine, C<delete_action>.
4128 my $line = shift || '';
4132 $line =~ s/^\./$dbline/;
4134 # Call delete_action with a null param to delete them all.
4135 # The '1' forces the eval to be true. It'll be false only
4136 # if delete_action blows up for some reason, in which case
4137 # we print $@ and get out.
4138 if ( $line eq '*' ) {
4139 eval { &delete_action(); 1 } or print $OUT $@ and return;
4142 # There's a real line number. Pass it to delete_action.
4143 # Error trapping is as above.
4144 elsif ( $line =~ /^(\S.*)/ ) {
4145 eval { &delete_action($1); 1 } or print $OUT $@ and return;
4148 # Swing and a miss. Bad syntax.
4151 "Deleting an action requires a line number, or '*' for all\n" ; # hint
4155 =head3 C<delete_action> (API)
4157 C<delete_action> accepts either a line number or C<undef>. If a line number
4158 is specified, we check for the line being executable (if it's not, it
4159 couldn't have had an action). If it is, we just take the action off (this
4160 will get any kind of an action, including breakpoints).
4166 if ( defined($i) ) {
4169 die "Line $i has no action .\n" if $dbline[$i] == 0;
4171 # Nuke whatever's there.
4172 $dbline{$i} =~ s/\0[^\0]*//; # \^a
4173 delete $dbline{$i} if $dbline{$i} eq '';
4176 print $OUT "Deleting all actions...\n";
4177 for my $file ( keys %had_breakpoints ) {
4178 local *dbline = $main::{ '_<' . $file };
4181 for ( $i = 1 ; $i <= $max ; $i++ ) {
4182 if ( defined $dbline{$i} ) {
4183 $dbline{$i} =~ s/\0[^\0]*//;
4184 delete $dbline{$i} if $dbline{$i} eq '';
4186 unless ( $had_breakpoints{$file} &= ~2 ) {
4187 delete $had_breakpoints{$file};
4189 } ## end for ($i = 1 ; $i <= $max...
4190 } ## end for my $file (keys %had_breakpoints)
4191 } ## end else [ if (defined($i))
4192 } ## end sub delete_action
4194 =head3 C<cmd_b> (command)
4196 Set breakpoints. Since breakpoints can be set in so many places, in so many
4197 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4198 we try to parse the command type, and then shuttle it off to an appropriate
4199 subroutine to actually do the work of setting the breakpoint in the right
4206 my $line = shift; # [.|line] [cond]
4209 # Make . the current line number if it's there..
4210 $line =~ s/^\.\b/$dbline/;
4212 # No line number, no condition. Simple break on current line.
4213 if ( $line =~ /^\s*$/ ) {
4214 &cmd_b_line( $dbline, 1 );
4217 # Break on load for a file.
4218 elsif ( $line =~ /^load\b\s*(.*)/ ) {
4224 # b compile|postpone <some sub> [<condition>]
4225 # The interpreter actually traps this one for us; we just put the
4226 # necessary condition in the %postponed hash.
4227 elsif ( $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4229 # Capture the condition if there is one. Make it true if none.
4230 my $cond = length $3 ? $3 : '1';
4232 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
4233 # if it was 'compile'.
4234 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
4236 # De-Perl4-ify the name - ' separators to ::.
4237 $subname =~ s/\'/::/g;
4239 # Qualify it into the current package unless it's already qualified.
4240 $subname = "${'package'}::" . $subname unless $subname =~ /::/;
4242 # Add main if it starts with ::.
4243 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4245 # Save the break type for this sub.
4246 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
4247 } ## end elsif ($line =~ ...
4248 # b <filename>:<line> [<condition>]
4249 elsif ($line =~ /\A(\S+[^:]):(\d+)\s*(.*)/ms) {
4250 my ($filename, $line_num, $cond) = ($1, $2, $3);
4251 cmd_b_filename_line(
4254 (length($cond) ? $cond : '1'),
4257 # b <sub name> [<condition>]
4258 elsif ( $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4262 $cond = length $2 ? $2 : '1';
4263 &cmd_b_sub( $subname, $cond );
4266 # b <line> [<condition>].
4267 elsif ( $line =~ /^(\d*)\s*(.*)/ ) {
4269 # Capture the line. If none, it's the current line.
4270 $line = $1 || $dbline;
4272 # If there's no condition, make it '1'.
4273 $cond = length $2 ? $2 : '1';
4276 &cmd_b_line( $line, $cond );
4279 # Line didn't make sense.
4281 print "confused by line($line)?\n";
4285 =head3 C<break_on_load> (API)
4287 We want to break when this file is loaded. Mark this file in the
4288 C<%break_on_load> hash, and note that it has a breakpoint in
4289 C<%had_breakpoints>.
4295 $break_on_load{$file} = 1;
4296 $had_breakpoints{$file} |= 1;
4299 =head3 C<report_break_on_load> (API)
4301 Gives us an array of filenames that are set to break on load. Note that
4302 only files with break-on-load are in here, so simply showing the keys
4307 sub report_break_on_load {
4308 sort keys %break_on_load;
4311 =head3 C<cmd_b_load> (command)
4313 We take the file passed in and try to find it in C<%INC> (which maps modules
4314 to files they came from). We mark those files for break-on-load via
4315 C<break_on_load> and then report that it was done.
4323 # This is a block because that way we can use a redo inside it
4324 # even without there being any looping structure at all outside it.
4327 # Save short name and full path if found.
4329 push @files, $::INC{$file} if $::INC{$file};
4331 # Tack on .pm and do it again unless there was a '.' in the name
4333 $file .= '.pm', redo unless $file =~ /\./;
4336 # Do the real work here.
4337 break_on_load($_) for @files;
4339 # All the files that have break-on-load breakpoints.
4340 @files = report_break_on_load;
4342 # Normalize for the purposes of our printing this.
4345 print $OUT "Will stop on load of '@files'.\n";
4346 } ## end sub cmd_b_load
4348 =head3 C<$filename_error> (API package global)
4350 Several of the functions we need to implement in the API need to work both
4351 on the current file and on other files. We don't want to duplicate code, so
4352 C<$filename_error> is used to contain the name of the file that's being
4353 worked on (if it's not the current one).
4355 We can now build functions in pairs: the basic function works on the current
4356 file, and uses C<$filename_error> as part of its error message. Since this is
4357 initialized to C<"">, no filename will appear when we are working on the
4360 The second function is a wrapper which does the following:
4366 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4370 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4374 Calls the first function.
4376 The first function works on the I<current> file (i.e., the one we changed to),
4377 and prints C<$filename_error> in the error message (the name of the other file)
4378 if it needs to. When the functions return, C<*dbline> is restored to point
4379 to the actual current file (the one we're executing in) and
4380 C<$filename_error> is restored to C<"">. This restores everything to
4381 the way it was before the second function was called at all.
4383 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4390 $filename_error = '';
4392 =head3 breakable_line(from, to) (API)
4394 The subroutine decides whether or not a line in the current file is breakable.
4395 It walks through C<@dbline> within the range of lines specified, looking for
4396 the first line that is breakable.
4398 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4399 first line I<after> C<$to> that's breakable, if there is one.
4401 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4402 first line I<before> C<$to> that's breakable, if there is one.
4406 sub breakable_line {
4408 my ( $from, $to ) = @_;
4410 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4413 # If there are at least 2 arguments, we're trying to search a range.
4416 # $delta is positive for a forward search, negative for a backward one.
4417 my $delta = $from < $to ? +1 : -1;
4419 # Keep us from running off the ends of the file.
4420 my $limit = $delta > 0 ? $#dbline : 1;
4422 # Clever test. If you're a mathematician, it's obvious why this
4423 # test works. If not:
4424 # If $delta is positive (going forward), $limit will be $#dbline.
4425 # If $to is less than $limit, ($limit - $to) will be positive, times
4426 # $delta of 1 (positive), so the result is > 0 and we should use $to
4427 # as the stopping point.
4429 # If $to is greater than $limit, ($limit - $to) is negative,
4430 # times $delta of 1 (positive), so the result is < 0 and we should
4431 # use $limit ($#dbline) as the stopping point.
4433 # If $delta is negative (going backward), $limit will be 1.
4434 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4435 # (negative) so the result is > 0, and we use $to as the stopping
4438 # If $to is less than zero, ($limit - $to) will be positive,
4439 # times $delta of -1 (negative), so the result is not > 0, and
4440 # we use $limit (1) as the stopping point.
4442 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4443 # (negative), still giving zero; the result is not > 0, and
4444 # we use $limit (1) as the stopping point.
4446 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4447 # (negative), giving a positive (>0) value, so we'll set $limit to
4450 $limit = $to if ( $limit - $to ) * $delta > 0;
4452 # The real search loop.
4453 # $i starts at $from (the point we want to start searching from).
4454 # We move through @dbline in the appropriate direction (determined
4455 # by $delta: either -1 (back) or +1 (ahead).
4456 # We stay in as long as we haven't hit an executable line
4457 # ($dbline[$i] == 0 means not executable) and we haven't reached
4458 # the limit yet (test similar to the above).
4459 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4461 } ## end if (@_ >= 2)
4463 # If $i points to a line that is executable, return that.
4464 return $i unless $dbline[$i] == 0;
4466 # Format the message and print it: no breakable lines in range.
4467 my ( $pl, $upto ) = ( '', '' );
4468 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4470 # If there's a filename in filename_error, we'll see it.
4472 die "Line$pl $from$upto$filename_error not breakable\n";
4473 } ## end sub breakable_line
4475 =head3 breakable_line_in_filename(file, from, to) (API)
4477 Like C<breakable_line>, but look in another file.
4481 sub breakable_line_in_filename {
4483 # Capture the file name.
4486 # Swap the magic line array over there temporarily.
4487 local *dbline = $main::{ '_<' . $f };
4489 # If there's an error, it's in this other file.
4490 local $filename_error = " of '$f'";
4492 # Find the breakable line.
4495 # *dbline and $filename_error get restored when this block ends.
4497 } ## end sub breakable_line_in_filename
4499 =head3 break_on_line(lineno, [condition]) (API)
4501 Adds a breakpoint with the specified condition (or 1 if no condition was
4502 specified) to the specified line. Dies if it can't.
4507 my ( $i, $cond ) = @_;
4509 # Always true if no condition supplied.
4510 $cond = 1 unless @_ >= 2;
4516 # Woops, not a breakable line. $filename_error allows us to say
4517 # if it was in a different file.
4518 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4520 # Mark this file as having breakpoints in it.
4521 $had_breakpoints{$filename} |= 1;
4523 # If there is an action or condition here already ...
4524 if ( $dbline{$i} ) {
4526 # ... swap this condition for the existing one.
4527 $dbline{$i} =~ s/^[^\0]*/$cond/;
4531 # Nothing here - just add the condition.
4532 $dbline{$i} = $cond;
4534 _set_breakpoint_enabled_status($filename, $i, 1);
4536 } ## end sub break_on_line
4538 =head3 cmd_b_line(line, [condition]) (command)
4540 Wrapper for C<break_on_line>. Prints the failure message if it
4546 eval { break_on_line(@_); 1 } or do {
4548 print $OUT $@ and return;
4550 } ## end sub cmd_b_line
4552 =head3 cmd_b_filename_line(line, [condition]) (command)
4554 Wrapper for C<break_on_filename_line>. Prints the failure message if it
4559 sub cmd_b_filename_line {
4560 eval { break_on_filename_line(@_); 1 } or do {
4562 print $OUT $@ and return;
4566 =head3 break_on_filename_line(file, line, [condition]) (API)
4568 Switches to the file specified and then calls C<break_on_line> to set
4573 sub break_on_filename_line {
4574 my ( $f, $i, $cond ) = @_;
4576 # Always true if condition left off.
4577 $cond = 1 unless @_ >= 3;
4579 # Switch the magical hash temporarily.
4580 local *dbline = $main::{ '_<' . $f };
4582 # Localize the variables that break_on_line uses to make its message.
4583 local $filename_error = " of '$f'";
4584 local $filename = $f;
4586 # Add the breakpoint.
4587 break_on_line( $i, $cond );
4588 } ## end sub break_on_filename_line
4590 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4592 Switch to another file, search the range of lines specified for an
4593 executable one, and put a breakpoint on the first one you find.
4597 sub break_on_filename_line_range {
4598 my ( $f, $from, $to, $cond ) = @_;
4600 # Find a breakable line if there is one.
4601 my $i = breakable_line_in_filename( $f, $from, $to );
4603 # Always true if missing.
4604 $cond = 1 unless @_ >= 3;
4606 # Add the breakpoint.
4607 break_on_filename_line( $f, $i, $cond );
4608 } ## end sub break_on_filename_line_range
4610 =head3 subroutine_filename_lines(subname, [condition]) (API)
4612 Search for a subroutine within a given file. The condition is ignored.
4613 Uses C<find_sub> to locate the desired subroutine.
4617 sub subroutine_filename_lines {
4618 my ( $subname, $cond ) = @_;
4620 # Returned value from find_sub() is fullpathname:startline-endline.
4621 # The match creates the list (fullpathname, start, end). Falling off
4622 # the end of the subroutine returns this implicitly.
4623 find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/;
4624 } ## end sub subroutine_filename_lines
4626 =head3 break_subroutine(subname) (API)
4628 Places a break on the first line possible in the specified subroutine. Uses
4629 C<subroutine_filename_lines> to find the subroutine, and
4630 C<break_on_filename_line_range> to place the break.
4634 sub break_subroutine {
4635 my $subname = shift;
4637 # Get filename, start, and end.
4638 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
4639 or die "Subroutine $subname not found.\n";
4641 # Null condition changes to '1' (always true).
4642 $cond = 1 unless @_ >= 2;
4644 # Put a break the first place possible in the range of lines
4645 # that make up this subroutine.
4646 break_on_filename_line_range( $file, $s, $e, @_ );
4647 } ## end sub break_subroutine
4649 =head3 cmd_b_sub(subname, [condition]) (command)
4651 We take the incoming subroutine name and fully-qualify it as best we can.
4655 =item 1. If it's already fully-qualified, leave it alone.
4657 =item 2. Try putting it in the current package.
4659 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
4661 =item 4. If it starts with '::', put it in 'main::'.
4665 After all this cleanup, we call C<break_subroutine> to try to set the
4671 my ( $subname, $cond ) = @_;
4673 # Add always-true condition if we have none.
4674 $cond = 1 unless @_ >= 2;
4676 # If the subname isn't a code reference, qualify it so that
4677 # break_subroutine() will work right.
4678 unless ( ref $subname eq 'CODE' ) {
4681 $subname =~ s/\'/::/g;
4684 # Put it in this package unless it's already qualified.
4685 $subname = "${'package'}::" . $subname
4686 unless $subname =~ /::/;
4688 # Requalify it into CORE::GLOBAL if qualifying it into this
4689 # package resulted in its not being defined, but only do so
4690 # if it really is in CORE::GLOBAL.
4691 $subname = "CORE::GLOBAL::$s"
4692 if not defined &$subname
4694 and defined &{"CORE::GLOBAL::$s"};
4696 # Put it in package 'main' if it has a leading ::.
4697 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4699 } ## end unless (ref $subname eq 'CODE')
4701 # Try to set the breakpoint.
4702 eval { break_subroutine( $subname, $cond ); 1 } or do {
4704 print $OUT $@ and return;
4706 } ## end sub cmd_b_sub
4708 =head3 C<cmd_B> - delete breakpoint(s) (command)
4710 The command mostly parses the command line and tries to turn the argument
4711 into a line spec. If it can't, it uses the current line. It then calls
4712 C<delete_breakpoint> to actually do the work.
4714 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
4715 thereby deleting all the breakpoints.
4722 # No line spec? Use dbline.
4723 # If there is one, use it if it's non-zero, or wipe it out if it is.
4724 my $line = ( $_[0] =~ /^\./ ) ? $dbline : shift || '';
4727 # If the line was dot, make the line the current one.
4728 $line =~ s/^\./$dbline/;
4730 # If it's * we're deleting all the breakpoints.
4731 if ( $line eq '*' ) {
4732 eval { &delete_breakpoint(); 1 } or print $OUT $@ and return;
4735 # If there is a line spec, delete the breakpoint on that line.
4736 elsif ( $line =~ /^(\S.*)/ ) {
4737 eval { &delete_breakpoint( $line || $dbline ); 1 } or do {
4739 print $OUT $@ and return;
4741 } ## end elsif ($line =~ /^(\S.*)/)
4746 "Deleting a breakpoint requires a line number, or '*' for all\n"
4751 =head3 delete_breakpoint([line]) (API)
4753 This actually does the work of deleting either a single breakpoint, or all
4756 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
4757 just drop out with a message saying so. If it is, we remove the condition
4758 part of the 'condition\0action' that says there's a breakpoint here. If,
4759 after we've done that, there's nothing left, we delete the corresponding
4760 line in C<%dbline> to signal that no action needs to be taken for this line.
4762 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
4763 which lists all currently-loaded files which have breakpoints. We then look
4764 at each line in each of these files, temporarily switching the C<%dbline>
4765 and C<@dbline> structures to point to the files in question, and do what
4766 we did in the single line case: delete the condition in C<@dbline>, and
4767 delete the key in C<%dbline> if nothing's left.
4769 We then wholesale delete C<%postponed>, C<%postponed_file>, and
4770 C<%break_on_load>, because these structures contain breakpoints for files
4771 and code that haven't been loaded yet. We can just kill these off because there
4772 are no magical debugger structures associated with them.
4776 sub delete_breakpoint {
4781 # If we got a line, delete just that one.
4782 if ( defined($i) ) {
4784 # Woops. This line wasn't breakable at all.
4785 die "Line $i not breakable.\n" if $dbline[$i] == 0;
4787 # Kill the condition, but leave any action.
4788 $dbline{$i} =~ s/^[^\0]*//;
4790 # Remove the entry entirely if there's no action left.
4791 if ($dbline{$i} eq '') {
4793 _delete_breakpoint_data_ref($fn, $i);
4797 # No line; delete them all.
4799 print $OUT "Deleting all breakpoints...\n";
4801 # %had_breakpoints lists every file that had at least one
4803 for my $file ( keys %had_breakpoints ) {
4805 # Switch to the desired file temporarily.
4806 local *dbline = $main::{ '_<' . $file };
4811 # For all lines in this file ...
4812 for ( $i = 1 ; $i <= $max ; $i++ ) {
4814 # If there's a breakpoint or action on this line ...
4815 if ( defined $dbline{$i} ) {
4817 # ... remove the breakpoint.
4818 $dbline{$i} =~ s/^[^\0]+//;
4819 if ( $dbline{$i} =~ s/^\0?$// ) {
4821 # Remove the entry altogether if no action is there.
4823 _delete_breakpoint_data_ref($file, $i);
4825 } ## end if (defined $dbline{$i...
4826 } ## end for ($i = 1 ; $i <= $max...
4828 # If, after we turn off the "there were breakpoints in this file"
4829 # bit, the entry in %had_breakpoints for this file is zero,
4830 # we should remove this file from the hash.
4831 if ( not $had_breakpoints{$file} &= ~1 ) {
4832 delete $had_breakpoints{$file};
4834 } ## end for my $file (keys %had_breakpoints)
4836 # Kill off all the other breakpoints that are waiting for files that
4837 # haven't been loaded yet.
4839 undef %postponed_file;
4840 undef %break_on_load;
4841 } ## end else [ if (defined($i))
4842 } ## end sub delete_breakpoint
4844 =head3 cmd_stop (command)
4846 This is meant to be part of the new command API, but it isn't called or used
4847 anywhere else in the debugger. XXX It is probably meant for use in development
4852 sub cmd_stop { # As on ^C, but not signal-safy.
4856 =head3 C<cmd_e> - threads
4858 Display the current thread id:
4862 This could be how (when implemented) to send commands to this thread id (e cmd)
4863 or that thread id (e tid cmd).
4870 unless (exists($INC{'threads.pm'})) {
4871 print "threads not loaded($ENV{PERL5DB_THREADED})
4872 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4874 my $tid = threads->tid;
4875 print "thread id: $tid\n";
4879 =head3 C<cmd_E> - list of thread ids
4881 Display the list of available thread ids:
4885 This could be used (when implemented) to send commands to all threads (E cmd).
4892 unless (exists($INC{'threads.pm'})) {
4893 print "threads not loaded($ENV{PERL5DB_THREADED})
4894 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4896 my $tid = threads->tid;
4897 print "thread ids: ".join(', ',
4898 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
4903 =head3 C<cmd_h> - help command (command)
4905 Does the work of either
4911 Showing all the debugger help
4915 Showing help for a specific command
4924 # If we have no operand, assume null.
4925 my $line = shift || '';
4927 # 'h h'. Print the long-format help.
4928 if ( $line =~ /^h\s*/ ) {
4932 # 'h <something>'. Search for the command and print only its help.
4933 elsif ( $line =~ /^(\S.*)$/ ) {
4935 # support long commands; otherwise bogus errors
4936 # happen when you ask for h on <CR> for example
4937 my $asked = $1; # the command requested
4938 # (for proper error message)
4940 my $qasked = quotemeta($asked); # for searching; we don't
4941 # want to use it as a pattern.
4942 # XXX: finds CR but not <CR>
4944 # Search the help string for the command.
4946 $help =~ /^ # Start of a line
4948 (?:[IB]<) # Optional markup
4949 $qasked # The requested command
4954 # It's there; pull it out and print it.
4958 (?:[IB]<) # Optional markup
4959 $qasked # The command
4960 ([\s\S]*?) # Description line(s)
4961 \n) # End of last description line
4962 (?!\s) # Next line not starting with
4971 # Not found; not a debugger command.
4973 print_help("B<$asked> is not a debugger command.\n");
4975 } ## end elsif ($line =~ /^(\S.*)$/)
4977 # 'h' - print the summary help.
4979 print_help($summary);
4983 =head3 C<cmd_i> - inheritance display
4985 Display the (nested) parentage of the module or object given.
4992 foreach my $isa ( split( /\s+/, $line ) ) {
5001 defined( ${"$_\::VERSION"} )
5002 ? ' ' . ${"$_\::VERSION"}
5004 } @{mro::get_linear_isa(ref($isa) || $isa)}
5010 =head3 C<cmd_l> - list lines (command)
5012 Most of the command is taken up with transforming all the different line
5013 specification syntaxes into 'start-stop'. After that is done, the command
5014 runs a loop over C<@dbline> for the specified range of lines. It handles
5015 the printing of each line and any markers (C<==E<gt>> for current line,
5016 C<b> for break on this line, C<a> for action on this line, C<:> for this
5019 We save the last line listed in the C<$start> global for further listing
5025 my $current_line = $line;
5029 # If this is '-something', delete any spaces after the dash.
5030 $line =~ s/^-\s*$/-/;
5032 # If the line is '$something', assume this is a scalar containing a
5034 if ( $line =~ /^(\$.*)/s ) {
5036 # Set up for DB::eval() - evaluate in *user* context.
5041 # Ooops. Bad scalar.
5042 print( $OUT "Error: $@\n" ), next CMD if $@;
5044 # Good scalar. If it's a reference, find what it points to.
5046 print( $OUT "Interpreted as: $1 $s\n" );
5049 # Call self recursively to really do the command.
5051 } ## end if ($line =~ /^(\$.*)/s)
5053 # l name. Try to find a sub by that name.
5054 elsif ( $line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s ) {
5055 my $s = $subname = $1;
5058 $subname =~ s/\'/::/;
5060 # Put it in this package unless it starts with ::.
5061 $subname = $package . "::" . $subname unless $subname =~ /::/;
5063 # Put it in CORE::GLOBAL if t doesn't start with :: and
5064 # it doesn't live in this package and it lives in CORE::GLOBAL.
5065 $subname = "CORE::GLOBAL::$s"
5066 if not defined &$subname
5068 and defined &{"CORE::GLOBAL::$s"};
5070 # Put leading '::' names into 'main::'.
5071 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
5073 # Get name:start-stop from find_sub, and break this up at
5075 @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
5077 # Pull off start-stop.
5078 $subrange = pop @pieces;
5080 # If the name contained colons, the split broke it up.
5081 # Put it back together.
5082 $file = join( ':', @pieces );
5084 # If we're not in that file, switch over to it.
5085 if ( $file ne $filename ) {
5086 print $OUT "Switching to file '$file'.\n"
5087 unless $slave_editor;
5089 # Switch debugger's magic structures.
5090 *dbline = $main::{ '_<' . $file };
5093 } ## end if ($file ne $filename)
5095 # Subrange is 'start-stop'. If this is less than a window full,
5096 # swap it to 'start+', which will list a window from the start point.
5098 if ( eval($subrange) < -$window ) {
5099 $subrange =~ s/-.*/+/;
5102 # Call self recursively to list the range.
5104 &cmd_l( 'l', $subrange );
5105 } ## end if ($subrange)
5109 print $OUT "Subroutine $subname not found.\n";
5111 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s)
5114 elsif ( $line =~ /^\s*$/ ) {
5116 # Compute new range to list.
5117 $incr = $window - 1;
5118 $line = $start . '-' . ( $start + $incr );
5121 &cmd_l( 'l', $line );
5124 # l [start]+number_of_lines
5125 elsif ( $line =~ /^(\d*)\+(\d*)$/ ) {
5127 # Don't reset start for 'l +nnn'.
5130 # Increment for list. Use window size if not specified.
5131 # (Allows 'l +' to work.)
5133 $incr = $window - 1 unless $incr;
5135 # Create a line range we'll understand, and recurse to do it.
5136 $line = $start . '-' . ( $start + $incr );
5137 &cmd_l( 'l', $line );
5138 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/)
5140 # l start-stop or l start,stop
5141 elsif ( $line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/ ) {
5143 # Determine end point; use end of file if not specified.
5144 $end = ( !defined $2 ) ? $max : ( $4 ? $4 : $2 );
5146 # Go on to the end, and then stop.
5147 $end = $max if $end > $max;
5149 # Determine start line.
5151 $i = $line if $i eq '.';
5155 # If we're running under a slave editor, force it to show the lines.
5156 if ($slave_editor) {
5157 print $OUT "\032\032$filename:$i:0\n";
5161 # We're doing it ourselves. We want to show the line and special
5163 # - the current line in execution
5164 # - whether a line is breakable or not
5165 # - whether a line has a break or not
5166 # - whether a line has an action or not
5168 for ( ; $i <= $end ; $i++ ) {
5170 # Check for breakpoints and actions.
5171 my ( $stop, $action );
5172 ( $stop, $action ) = split( /\0/, $dbline{$i} )
5175 # ==> if this is the current line in execution,
5176 # : if it's breakable.
5178 ( $i == $current_line and $filename eq $filename_ini )
5180 : ( $dbline[$i] + 0 ? ':' : ' ' );
5182 # Add break and action indicators.
5183 $arrow .= 'b' if $stop;
5184 $arrow .= 'a' if $action;
5187 print $OUT "$i$arrow\t", $dbline[$i];
5189 # Move on to the next line. Drop out on an interrupt.
5190 $i++, last if $signal;
5191 } ## end for (; $i <= $end ; $i++)
5193 # Line the prompt up; print a newline if the last line listed
5194 # didn't have a newline.
5195 print $OUT "\n" unless $dbline[ $i - 1 ] =~ /\n$/;
5196 } ## end else [ if ($slave_editor)
5198 # Save the point we last listed to in case another relative 'l'
5199 # command is desired. Don't let it run off the end.
5201 $start = $max if $start > $max;
5202 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/)
5205 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5207 To list breakpoints, the command has to look determine where all of them are
5208 first. It starts a C<%had_breakpoints>, which tells us what all files have
5209 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5210 magic source and breakpoint data structures) to the file, and then look
5211 through C<%dbline> for lines with breakpoints and/or actions, listing them
5212 out. We look through C<%postponed> not-yet-compiled subroutines that have
5213 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5214 that have breakpoints.
5216 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5223 # If no argument, list everything. Pre-5.8.0 version always lists
5225 my $arg = shift || 'abw';
5226 $arg = 'abw' unless $CommandSet eq '580'; # sigh...
5228 # See what is wanted.
5229 my $action_wanted = ( $arg =~ /a/ ) ? 1 : 0;
5230 my $break_wanted = ( $arg =~ /b/ ) ? 1 : 0;
5231 my $watch_wanted = ( $arg =~ /w/ ) ? 1 : 0;
5233 # Breaks and actions are found together, so we look in the same place
5235 if ( $break_wanted or $action_wanted ) {
5237 # Look in all the files with breakpoints...
5238 for my $file ( keys %had_breakpoints ) {
5240 # Temporary switch to this file.
5241 local *dbline = $main::{ '_<' . $file };
5243 # Set up to look through the whole file.
5245 my $was; # Flag: did we print something
5248 # For each line in the file ...
5249 for ( $i = 1 ; $i <= $max ; $i++ ) {
5251 # We've got something on this line.
5252 if ( defined $dbline{$i} ) {
5254 # Print the header if we haven't.
5255 print $OUT "$file:\n" unless $was++;
5258 print $OUT " $i:\t", $dbline[$i];
5260 # Pull out the condition and the action.
5261 ( $stop, $action ) = split( /\0/, $dbline{$i} );
5263 # Print the break if there is one and it's wanted.
5264 print $OUT " break if (", $stop, ")\n"
5268 # Print the action if there is one and it's wanted.
5269 print $OUT " action: ", $action, "\n"
5273 # Quit if the user hit interrupt.
5275 } ## end if (defined $dbline{$i...
5276 } ## end for ($i = 1 ; $i <= $max...
5277 } ## end for my $file (keys %had_breakpoints)
5278 } ## end if ($break_wanted or $action_wanted)
5280 # Look for breaks in not-yet-compiled subs:
5281 if ( %postponed and $break_wanted ) {
5282 print $OUT "Postponed breakpoints in subroutines:\n";
5284 for $subname ( keys %postponed ) {
5285 print $OUT " $subname\t$postponed{$subname}\n";
5288 } ## end if (%postponed and $break_wanted)
5290 # Find files that have not-yet-loaded breaks:
5291 my @have = map { # Combined keys
5292 keys %{ $postponed_file{$_} }
5293 } keys %postponed_file;
5295 # If there are any, list them.
5296 if ( @have and ( $break_wanted or $action_wanted ) ) {
5297 print $OUT "Postponed breakpoints in files:\n";
5298 my ( $file, $line );
5300 for $file ( keys %postponed_file ) {
5301 my $db = $postponed_file{$file};
5302 print $OUT " $file:\n";
5303 for $line ( sort { $a <=> $b } keys %$db ) {
5304 print $OUT " $line:\n";
5305 my ( $stop, $action ) = split( /\0/, $$db{$line} );
5306 print $OUT " break if (", $stop, ")\n"
5309 print $OUT " action: ", $action, "\n"
5313 } ## end for $line (sort { $a <=>...
5315 } ## end for $file (keys %postponed_file)
5316 } ## end if (@have and ($break_wanted...
5317 if ( %break_on_load and $break_wanted ) {
5318 print $OUT "Breakpoints on load:\n";
5320 for $file ( keys %break_on_load ) {
5321 print $OUT " $file\n";
5324 } ## end if (%break_on_load and...
5325 if ($watch_wanted) {
5327 print $OUT "Watch-expressions:\n" if @to_watch;
5328 for my $expr (@to_watch) {
5329 print $OUT " $expr\n";
5332 } ## end if ($trace & 2)
5333 } ## end if ($watch_wanted)
5336 =head3 C<cmd_M> - list modules (command)
5338 Just call C<list_modules>.
5346 =head3 C<cmd_o> - options (command)
5348 If this is just C<o> by itself, we list the current settings via
5349 C<dump_option>. If there's a nonblank value following it, we pass that on to
5350 C<parse_options> for processing.
5356 my $opt = shift || ''; # opt[=val]
5358 # Nonblank. Try to parse and process.
5359 if ( $opt =~ /^(\S.*)/ ) {
5363 # Blank. List the current option settings.
5371 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5373 Advises the user that the O command has been renamed.
5378 print $OUT "The old O command is now the o command.\n"; # hint
5379 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5380 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5383 =head3 C<cmd_v> - view window (command)
5385 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5386 move back a few lines to list the selected line in context. Uses C<cmd_l>
5387 to do the actual listing after figuring out the range of line to request.
5395 # Extract the line to list around. (Astute readers will have noted that
5396 # this pattern will match whether or not a numeric line is specified,
5397 # which means that we'll always enter this loop (though a non-numeric
5398 # argument results in no action at all)).
5399 if ( $line =~ /^(\d*)$/ ) {
5401 # Total number of lines to list (a windowful).
5402 $incr = $window - 1;
5404 # Set the start to the argument given (if there was one).
5407 # Back up by the context amount.
5410 # Put together a linespec that cmd_l will like.
5411 $line = $start . '-' . ( $start + $incr );
5414 &cmd_l( 'l', $line );
5415 } ## end if ($line =~ /^(\d*)$/)
5418 =head3 C<cmd_w> - add a watch expression (command)
5420 The 5.8 version of this command adds a watch expression if one is specified;
5421 it does nothing if entered with no operands.
5423 We extract the expression, save it, evaluate it in the user's context, and
5424 save the value. We'll re-evaluate it each time the debugger passes a line,
5425 and will stop (see the code at the top of the command loop) if the value
5426 of any of the expressions changes.
5433 # Null expression if no arguments.
5434 my $expr = shift || '';
5436 # If expression is not null ...
5437 if ( $expr =~ /^(\S.*)/ ) {
5440 push @to_watch, $expr;
5442 # Parameterize DB::eval and call it to get the expression's value
5443 # in the user's context. This version can handle expressions which
5444 # return a list value.
5446 my ($val) = join( ' ', &eval );
5447 $val = ( defined $val ) ? "'$val'" : 'undef';
5449 # Save the current value of the expression.
5450 push @old_watch, $val;
5452 # We are now watching expressions.
5454 } ## end if ($expr =~ /^(\S.*)/)
5456 # You have to give one to get one.
5458 print $OUT "Adding a watch-expression requires an expression\n"; # hint
5462 =head3 C<cmd_W> - delete watch expressions (command)
5464 This command accepts either a watch expression to be removed from the list
5465 of watch expressions, or C<*> to delete them all.
5467 If C<*> is specified, we simply empty the watch expression list and the
5468 watch expression value list. We also turn off the bit that says we've got
5471 If an expression (or partial expression) is specified, we pattern-match
5472 through the expressions and remove the ones that match. We also discard
5473 the corresponding values. If no watch expressions are left, we turn off
5474 the I<watching expressions> bit.
5480 my $expr = shift || '';
5483 if ( $expr eq '*' ) {
5488 print $OUT "Deleting all watch expressions ...\n";
5491 @to_watch = @old_watch = ();
5494 # Delete one of them.
5495 elsif ( $expr =~ /^(\S.*)/ ) {
5497 # Where we are in the list.
5500 # For each expression ...
5501 foreach (@to_watch) {
5502 my $val = $to_watch[$i_cnt];
5504 # Does this one match the command argument?
5505 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
5506 # Yes. Turn it off, and its value too.
5507 splice( @to_watch, $i_cnt, 1 );
5508 splice( @old_watch, $i_cnt, 1 );
5511 } ## end foreach (@to_watch)
5513 # We don't bother to turn watching off because
5514 # a) we don't want to stop calling watchfunction() it it exists
5515 # b) foreach over a null list doesn't do anything anyway
5517 } ## end elsif ($expr =~ /^(\S.*)/)
5519 # No command arguments entered.
5522 "Deleting a watch-expression requires an expression, or '*' for all\n"
5527 ### END of the API section
5529 =head1 SUPPORT ROUTINES
5531 These are general support routines that are used in a number of places
5532 throughout the debugger.
5536 save() saves the user's versions of globals that would mess us up in C<@saved>,
5537 and installs the versions we like better.
5543 # Save eval failure, command failure, extended OS error, output field
5544 # separator, input record separator, output record separator and
5545 # the warning setting.
5546 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
5548 $, = ""; # output field separator is null string
5549 $/ = "\n"; # input record separator is newline
5550 $\ = ""; # output record separator is null string
5551 $^W = 0; # warnings are off
5554 =head2 C<print_lineinfo> - show where we are now
5556 print_lineinfo prints whatever it is that it is handed; it prints it to the
5557 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
5558 us to feed line information to a slave editor without messing up the
5563 sub print_lineinfo {
5565 # Make the terminal sensible if we're not the primary debugger.
5566 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
5570 } ## end sub print_lineinfo
5572 =head2 C<postponed_sub>
5574 Handles setting postponed breakpoints in subroutines once they're compiled.
5575 For breakpoints, we use C<DB::find_sub> to locate the source file and line
5576 range for the subroutine, then mark the file as having a breakpoint,
5577 temporarily switch the C<*dbline> glob over to the source file, and then
5578 search the given range of lines to find a breakable line. If we find one,
5579 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
5583 # The following takes its argument via $evalarg to preserve current @_
5587 # Get the subroutine name.
5588 my $subname = shift;
5590 # If this is a 'break +<n> if <condition>' ...
5591 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
5593 # If there's no offset, use '+0'.
5594 my $offset = $1 || 0;
5596 # find_sub's value is 'fullpath-filename:start-stop'. It's
5597 # possible that the filename might have colons in it too.
5598 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
5601 # We got the start line. Add the offset '+<n>' from
5602 # $postponed{subname}.
5605 # Switch to the file this sub is in, temporarily.
5606 local *dbline = $main::{ '_<' . $file };
5608 # No warnings, please.
5609 local $^W = 0; # != 0 is magical below
5611 # This file's got a breakpoint in it.
5612 $had_breakpoints{$file} |= 1;
5614 # Last line in file.
5617 # Search forward until we hit a breakable line or get to
5618 # the end of the file.
5619 ++$i until $dbline[$i] != 0 or $i >= $max;
5621 # Copy the breakpoint in and delete it from %postponed.
5622 $dbline{$i} = delete $postponed{$subname};
5625 # find_sub didn't find the sub.
5628 print $OUT "Subroutine $subname not found.\n";
5631 } ## end if ($postponed{$subname...
5632 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
5634 #print $OUT "In postponed_sub for '$subname'.\n";
5635 } ## end sub postponed_sub
5639 Called after each required file is compiled, but before it is executed;
5640 also called if the name of a just-compiled subroutine is a key of
5641 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
5642 etc.) into the just-compiled code.
5644 If this is a C<require>'d file, the incoming parameter is the glob
5645 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
5647 If it's a subroutine, the incoming parameter is the subroutine name.
5653 # If there's a break, process it.
5654 if ($ImmediateStop) {
5656 # Right, we've stopped. Turn it off.
5659 # Enter the command loop when DB::DB gets called.
5663 # If this is a subroutine, let postponed_sub() deal with it.
5664 return &postponed_sub unless ref \$_[0] eq 'GLOB';
5666 # Not a subroutine. Deal with the file.
5667 local *dbline = shift;
5668 my $filename = $dbline;
5669 $filename =~ s/^_<//;
5671 $signal = 1, print $OUT "'$filename' loaded...\n"
5672 if $break_on_load{$filename};
5673 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
5675 # Do we have any breakpoints to put in this file?
5676 return unless $postponed_file{$filename};
5678 # Yes. Mark this file as having breakpoints.
5679 $had_breakpoints{$filename} |= 1;
5681 # "Cannot be done: insufficient magic" - we can't just put the
5682 # breakpoints saved in %postponed_file into %dbline by assigning
5683 # the whole hash; we have to do it one item at a time for the
5684 # breakpoints to be set properly.
5685 #%dbline = %{$postponed_file{$filename}};
5687 # Set the breakpoints, one at a time.
5690 for $key ( keys %{ $postponed_file{$filename} } ) {
5692 # Stash the saved breakpoint into the current file's magic line array.
5693 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
5696 # This file's been compiled; discard the stored breakpoints.
5697 delete $postponed_file{$filename};
5699 } ## end sub postponed
5703 C<dumpit> is the debugger's wrapper around dumpvar.pl.
5705 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
5706 a reference to a variable (the thing to be dumped) as its input.
5708 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
5709 the currently-selected filehandle, thank you very much). The current
5710 values of the package globals C<$single> and C<$trace> are backed up in
5711 lexicals, and they are turned off (this keeps the debugger from trying
5712 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
5713 preserve its current value and it is set to zero to prevent entry/exit
5714 messages from printing, and C<$doret> is localized as well and set to -2 to
5715 prevent return values from being shown.
5717 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
5718 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
5719 installed version in C<@INC>, yours will be used instead. Possible security
5722 It then checks to see if the subroutine C<main::dumpValue> is now defined
5723 (it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
5724 localizes the globals necessary for things to be sane when C<main::dumpValue()>
5725 is called, and picks up the variable to be dumped from the parameter list.
5727 It checks the package global C<%options> to see if there's a C<dumpDepth>
5728 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
5729 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
5730 structure: -1 means dump everything.
5732 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
5735 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
5736 and we then return to the caller.
5742 # Save the current output filehandle and switch to the one
5743 # passed in as the first parameter.
5744 local ($savout) = select(shift);
5746 # Save current settings of $single and $trace, and then turn them off.
5747 my $osingle = $single;
5748 my $otrace = $trace;
5749 $single = $trace = 0;
5751 # XXX Okay, what do $frame and $doret do, again?
5755 # Load dumpvar.pl unless we've already got the sub we need from it.
5756 unless ( defined &main::dumpValue ) {
5757 do 'dumpvar.pl' or die $@;
5760 # If the load succeeded (or we already had dumpvalue()), go ahead
5762 if ( defined &main::dumpValue ) {
5767 my $maxdepth = shift || $option{dumpDepth};
5768 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
5769 &main::dumpValue( $v, $maxdepth );
5770 } ## end if (defined &main::dumpValue)
5772 # Oops, couldn't load dumpvar.pl.
5775 print $OUT "dumpvar.pl not available.\n";
5778 # Reset $single and $trace to their old values.
5782 # Restore the old filehandle.
5786 =head2 C<print_trace>
5788 C<print_trace>'s job is to print a stack trace. It does this via the
5789 C<dump_trace> routine, which actually does all the ferreting-out of the
5790 stack trace data. C<print_trace> takes care of formatting it nicely and
5791 printing it to the proper filehandle.
5799 The filehandle to print to.
5803 How many frames to skip before starting trace.
5807 How many frames to print.
5811 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
5815 The original comment below seems to be noting that the traceback may not be
5816 correct if this routine is called in a tied method.
5820 # Tied method do not create a context, so may get wrong message:
5826 # If this is going to a slave editor, but we're not the primary
5827 # debugger, reset it first.
5829 if $fh eq $LINEINFO # slave editor
5830 and $LINEINFO eq $OUT # normal output
5831 and $term_pid != $$; # not the primary
5833 # Collect the actual trace information to be formatted.
5834 # This is an array of hashes of subroutine call info.
5835 my @sub = dump_trace( $_[0] + 1, $_[1] );
5837 # Grab the "short report" flag from @_.
5838 my $short = $_[2]; # Print short report, next one for sub name
5840 # Run through the traceback info, format it, and print it.
5842 for ( $i = 0 ; $i <= $#sub ; $i++ ) {
5844 # Drop out if the user has lost interest and hit control-C.
5847 # Set the separator so arrys print nice.
5850 # Grab and stringify the arguments if they are there.
5852 defined $sub[$i]{args}
5853 ? "(@{ $sub[$i]{args} })"
5856 # Shorten them up if $maxtrace says they're too long.
5857 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
5858 if length $args > $maxtrace;
5860 # Get the file name.
5861 my $file = $sub[$i]{file};
5863 # Put in a filename header if short is off.
5864 $file = $file eq '-e' ? $file : "file '$file'" unless $short;
5866 # Get the actual sub's name, and shorten to $maxtrace's requirement.
5868 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
5870 # Short report uses trimmed file and sub names.
5872 my $sub = @_ >= 4 ? $_[3] : $s;
5873 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
5874 } ## end if ($short)
5876 # Non-short report includes full names.
5878 print $fh "$sub[$i]{context} = $s$args"
5879 . " called from $file"
5880 . " line $sub[$i]{line}\n";
5882 } ## end for ($i = 0 ; $i <= $#sub...
5883 } ## end sub print_trace
5885 =head2 dump_trace(skip[,count])
5887 Actually collect the traceback information available via C<caller()>. It does
5888 some filtering and cleanup of the data, but mostly it just collects it to
5889 make C<print_trace()>'s job easier.
5891 C<skip> defines the number of stack frames to be skipped, working backwards
5892 from the most current. C<count> determines the total number of frames to
5893 be returned; all of them (well, the first 10^9) are returned if C<count>
5896 This routine returns a list of hashes, from most-recent to least-recent
5897 stack frame. Each has the following keys and values:
5901 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
5903 =item * C<sub> - subroutine name, or C<eval> information
5905 =item * C<args> - undef, or a reference to an array of arguments
5907 =item * C<file> - the file in which this item was defined (if any)
5909 =item * C<line> - the line on which it was defined
5917 # How many levels to skip.
5920 # How many levels to show. (1e9 is a cheap way of saying "all of them";
5921 # it's unlikely that we'll have more than a billion stack frames. If you
5922 # do, you've got an awfully big machine...)
5923 my $count = shift || 1e9;
5925 # We increment skip because caller(1) is the first level *back* from
5926 # the current one. Add $skip to the count of frames so we have a
5927 # simple stop criterion, counting from $skip to $count+$skip.
5931 # These variables are used to capture output from caller();
5932 my ( $p, $file, $line, $sub, $h, $context );
5934 my ( $e, $r, @a, @sub, $args );
5936 # XXX Okay... why'd we do that?
5937 my $nothard = not $frame & 8;
5940 # Do not want to trace this.
5941 my $otrace = $trace;
5944 # Start out at the skip count.
5945 # If we haven't reached the number of frames requested, and caller() is
5946 # still returning something, stay in the loop. (If we pass the requested
5947 # number of stack frames, or we run out - caller() returns nothing - we
5949 # Up the stack frame index to go back one more level each time.
5953 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
5958 # Go through the arguments and save them for later.
5962 if ( not defined $arg ) { # undefined parameter
5966 elsif ( $nothard and tied $arg ) { # tied parameter
5969 elsif ( $nothard and $type = ref $arg ) { # reference
5970 push @a, "ref($type)";
5972 else { # can be stringified
5974 "$arg"; # Safe to stringify now - should not call f().
5976 # Backslash any single-quotes or backslashes.
5979 # Single-quote it unless it's a number or a colon-separated
5982 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
5984 # Turn high-bit characters into meta-whatever.
5985 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
5987 # Turn control characters into ^-whatever.
5988 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
5991 } ## end else [ if (not defined $arg)
5992 } ## end for $arg (@args)
5994 # If context is true, this is array (@)context.
5995 # If context is false, this is scalar ($) context.
5996 # If neither, context isn't defined. (This is apparently a 'can't
5998 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
6000 # if the sub has args ($h true), make an anonymous array of the
6002 $args = $h ? [@a] : undef;
6004 # remove trailing newline-whitespace-semicolon-end of line sequence
6005 # from the eval text, if any.
6006 $e =~ s/\n\s*\;\s*\Z// if $e;
6008 # Escape backslashed single-quotes again if necessary.
6009 $e =~ s/([\\\'])/\\$1/g if $e;
6011 # if the require flag is true, the eval text is from a require.
6013 $sub = "require '$e'";
6016 # if it's false, the eval text is really from an eval.
6017 elsif ( defined $r ) {
6021 # If the sub is '(eval)', this is a block eval, meaning we don't
6022 # know what the eval'ed text actually was.
6023 elsif ( $sub eq '(eval)' ) {
6024 $sub = "eval {...}";
6027 # Stick the collected information into @sub as an anonymous hash.
6031 context => $context,
6039 # Stop processing frames if the user hit control-C.
6041 } ## end for ($i = $skip ; $i < ...
6043 # Restore the trace value again.
6046 } ## end sub dump_trace
6050 C<action()> takes input provided as the argument to an add-action command,
6051 either pre- or post-, and makes sure it's a complete command. It doesn't do
6052 any fancy parsing; it just keeps reading input until it gets a string
6053 without a trailing backslash.
6060 while ( $action =~ s/\\$// ) {
6062 # We have a backslash on the end. Read more.
6064 } ## end while ($action =~ s/\\$//)
6066 # Return the assembled action.
6072 This routine mostly just packages up a regular expression to be used
6073 to check that the thing it's being matched against has properly-matched
6076 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
6077 speeds things up by only creating the qr//'ed expression once; if it's
6078 already defined, we don't try to define it again. A speed hack.
6084 # I hate using globals!
6085 $balanced_brace_re ||= qr{
6088 (?> [^{}] + ) # Non-parens without backtracking
6090 (??{ $balanced_brace_re }) # Group with matching parens
6094 return $_[0] !~ m/$balanced_brace_re/;
6095 } ## end sub unbalanced
6099 C<gets()> is a primitive (very primitive) routine to read continuations.
6100 It was devised for reading continuations for actions.
6101 it just reads more input with C<readline()> and returns it.
6106 &readline("cont: ");
6109 =head2 C<DB::system()> - handle calls to<system()> without messing up the debugger
6111 The C<system()> function assumes that it can just go ahead and use STDIN and
6112 STDOUT, but under the debugger, we want it to use the debugger's input and
6115 C<DB::system()> socks away the program's STDIN and STDOUT, and then substitutes
6116 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
6117 and then puts everything back again.
6123 # We save, change, then restore STDIN and STDOUT to avoid fork() since
6124 # some non-Unix systems can do system() but have problems with fork().
6125 open( SAVEIN, "<&STDIN" ) || &warn("Can't save STDIN");
6126 open( SAVEOUT, ">&STDOUT" ) || &warn("Can't save STDOUT");
6127 open( STDIN, "<&IN" ) || &warn("Can't redirect STDIN");
6128 open( STDOUT, ">&OUT" ) || &warn("Can't redirect STDOUT");
6130 # XXX: using csh or tcsh destroys sigint retvals!
6132 open( STDIN, "<&SAVEIN" ) || &warn("Can't restore STDIN");
6133 open( STDOUT, ">&SAVEOUT" ) || &warn("Can't restore STDOUT");
6137 # most of the $? crud was coping with broken cshisms
6139 &warn( "(Command exited ", ( $? >> 8 ), ")\n" );
6143 "(Command died of SIG#",
6145 ( ( $? & 128 ) ? " -- core dumped" : "" ),
6154 =head1 TTY MANAGEMENT
6156 The subs here do some of the terminal management for multiple debuggers.
6160 Top-level function called when we want to set up a new terminal for use
6163 If the C<noTTY> debugger option was set, we'll either use the terminal
6164 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
6165 to find one. If we're a forked debugger, we call C<resetterm> to try to
6166 get a whole new terminal if we can.
6168 In either case, we set up the terminal next. If the C<ReadLine> option was
6169 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6170 the appropriate attributes. We then
6176 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6179 require Term::ReadLine;
6181 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6184 my ( $i, $o ) = split $tty, /,/;
6185 $o = $i unless defined $o;
6186 open( IN, "<$i" ) or die "Cannot open TTY '$i' for read: $!";
6187 open( OUT, ">$o" ) or die "Cannot open TTY '$o' for write: $!";
6190 my $sel = select($OUT);
6195 # We don't have a TTY - try to find one via Term::Rendezvous.
6197 require Term::Rendezvous;
6199 # See if we have anything to pass to Term::Rendezvous.
6200 # Use $HOME/.perldbtty$$ if not.
6201 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6203 # Rendezvous and get the filehandles.
6204 my $term_rv = Term::Rendezvous->new( $rv );
6206 $OUT = $term_rv->OUT;
6207 } ## end else [ if ($tty)
6208 } ## end if ($notty)
6210 # We're a daughter debugger. Try to fork off another TTY.
6211 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6215 # If we shouldn't use Term::ReadLine, don't.
6217 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6220 # We're using Term::ReadLine. Get all the attributes for this terminal.
6222 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6224 $rl_attribs = $term->Attribs;
6225 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6226 if defined $rl_attribs->{basic_word_break_characters}
6227 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6228 $rl_attribs->{special_prefixes} = '$@&%';
6229 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6230 $rl_attribs->{completion_function} = \&db_complete;
6231 } ## end else [ if (!$rl)
6233 # Set up the LINEINFO filehandle.
6234 $LINEINFO = $OUT unless defined $LINEINFO;
6235 $lineinfo = $console unless defined $lineinfo;
6241 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6242 $term->SetHistory(@hist);
6245 # XXX Ornaments are turned on unconditionally, which is not
6246 # always a good thing.
6247 ornaments($ornaments) if defined $ornaments;
6249 } ## end sub setterm
6252 $histfile //= option_val("HistFile", undef);
6253 return unless defined $histfile;
6254 open my $fh, "<", $histfile or return;
6265 return unless defined $histfile;
6266 eval { require File::Path } or return;
6267 eval { require File::Basename } or return;
6268 File::Path::mkpath(File::Basename::dirname($histfile));
6269 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6270 $histsize //= option_val("HistSize",100);
6271 my @copy = grep { $_ ne '?' } @hist;
6272 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6273 for ($start .. $#copy) {
6274 print $fh "$copy[$_]\n";
6276 close $fh or die "Could not write '$histfile': $!";
6279 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6281 When the process being debugged forks, or the process invokes a command
6282 via C<system()> which starts a new debugger, we need to be able to get a new
6283 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6284 fight over the terminal, and you can never quite be sure who's going to get the
6285 input you're typing.
6287 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6288 is tasked with doing all the necessary operating system mojo to get a new
6289 TTY (and probably another window) and to direct the new debugger to read and
6292 The debugger provides C<get_fork_TTY> functions which work for TCP
6293 socket servers, X11, OS/2, and Mac OS X. Other systems are not
6294 supported. You are encouraged to write C<get_fork_TTY> functions which
6295 work for I<your> platform and contribute them.
6297 =head3 C<socket_get_fork_TTY>
6301 sub connect_remoteport {
6304 my $socket = IO::Socket::INET->new(
6306 PeerAddr => $remoteport,
6310 die "Unable to connect to remote host: $remoteport\n";
6315 sub socket_get_fork_TTY {
6316 $tty = $LINEINFO = $IN = $OUT = connect_remoteport();
6318 # Do I need to worry about setting $term?
6320 reset_IN_OUT( $IN, $OUT );
6324 =head3 C<xterm_get_fork_TTY>
6326 This function provides the C<get_fork_TTY> function for X11. If a
6327 program running under the debugger forks, a new <xterm> window is opened and
6328 the subsidiary debugger is directed there.
6330 The C<open()> call is of particular note here. We have the new C<xterm>
6331 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6332 command (which prints the device name of the TTY we'll want to use for input
6333 and output to STDOUT, then C<sleep> for a very long time, routing this output
6334 to file number 3. This way we can simply read from the <XT> filehandle (which
6335 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6337 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6342 sub xterm_get_fork_TTY {
6343 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6345 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6348 # Get the output from 'tty' and clean it up a little.
6352 $pidprompt = ''; # Shown anyway in titlebar
6354 # We need $term defined or we can not switch to the newly created xterm
6355 if ($tty ne '' && !defined $term) {
6356 require Term::ReadLine;
6358 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6361 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6364 # There's our new TTY.
6366 } ## end sub xterm_get_fork_TTY
6368 =head3 C<os2_get_fork_TTY>
6370 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6374 # This example function resets $IN, $OUT itself
6376 sub os2_get_fork_TTY { # A simplification of the following (and works without):
6378 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6379 my %opt = ( title => "Daughter Perl debugger $pids $name",
6380 ($rl ? (read_by_key => 1) : ()) );
6381 require OS2::Process;
6382 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
6384 $pidprompt = ''; # Shown anyway in titlebar
6385 reset_IN_OUT($in, $out);
6387 return ''; # Indicate that reset_IN_OUT is called
6388 } ## end sub os2_get_fork_TTY
6390 =head3 C<macosx_get_fork_TTY>
6392 The Mac OS X version uses AppleScript to tell Terminal.app to create
6397 # Notes about Terminal.app's AppleScript support,
6398 # (aka things that might break in future OS versions).
6400 # The "do script" command doesn't return a reference to the new window
6401 # it creates, but since it appears frontmost and windows are enumerated
6402 # front to back, we can use "first window" === "window 1".
6404 # Since "do script" is implemented by supplying the argument (plus a
6405 # return character) as terminal input, there's a potential race condition
6406 # where the debugger could beat the shell to reading the command.
6407 # To prevent this, we wait for the screen to clear before proceeding.
6410 # There's no direct accessor for the tty device name, so we fiddle
6411 # with the window title options until it says what we want.
6414 # There _is_ a direct accessor for the tty device name, _and_ there's
6415 # a new possible component of the window title (the name of the settings
6416 # set). A separate version is needed.
6418 my @script_versions=
6420 ([237, <<'__LEOPARD__'],
6421 tell application "Terminal"
6422 do script "clear;exec sleep 100000"
6423 tell first tab of first window
6425 set custom title to "forked perl debugger"
6426 set title displays custom title to true
6427 repeat while (length of first paragraph of (get contents)) > 0
6435 [100, <<'__JAGUAR_TIGER__'],
6436 tell application "Terminal"
6437 do script "clear;exec sleep 100000"
6439 set title displays shell path to false
6440 set title displays window size to false
6441 set title displays file name to false
6442 set title displays device name to true
6443 set title displays custom title to true
6444 set custom title to ""
6445 copy "/dev/" & name to thetty
6446 set custom title to "forked perl debugger"
6447 repeat while (length of first paragraph of (get contents)) > 0
6457 sub macosx_get_fork_TTY
6459 my($version,$script,$pipe,$tty);
6461 return unless $version=$ENV{TERM_PROGRAM_VERSION};
6462 foreach my $entry (@script_versions) {
6463 if ($version>=$entry->[0]) {
6464 $script=$entry->[1];
6468 return unless defined($script);
6469 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script);
6470 $tty=readline($pipe);
6472 return unless defined($tty) && $tty =~ m(^/dev/);
6477 =head2 C<create_IN_OUT($flags)>
6479 Create a new pair of filehandles, pointing to a new TTY. If impossible,
6480 try to diagnose why.
6486 =item * 1 - Don't know how to create a new TTY.
6488 =item * 2 - Debugger has forked, but we can't get a new TTY.
6490 =item * 4 - standard debugger startup is happening.
6496 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
6498 # If we know how to get a new TTY, do it! $in will have
6499 # the TTY name if get_fork_TTY works.
6500 my $in = &get_fork_TTY if defined &get_fork_TTY;
6502 # It used to be that
6503 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
6505 if ( not defined $in ) {
6508 # We don't know how.
6509 print_help(<<EOP) if $why == 1;
6510 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
6514 print_help(<<EOP) if $why == 2;
6515 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
6516 This may be an asynchronous session, so the parent debugger may be active.
6519 # Note that both debuggers are fighting over the same input.
6520 print_help(<<EOP) if $why != 4;
6521 Since two debuggers fight for the same TTY, input is severely entangled.
6525 I know how to switch the output to a different window in xterms, OS/2
6526 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
6527 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
6528 B<DB::get_fork_TTY()> returning this.
6530 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
6531 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
6534 } ## end if (not defined $in)
6535 elsif ( $in ne '' ) {
6539 $console = ''; # Indicate no need to open-from-the-console
6542 } ## end sub create_IN_OUT
6546 Handles rejiggering the prompt when we've forked off a new debugger.
6548 If the new debugger happened because of a C<system()> that invoked a
6549 program under the debugger, the arrow between the old pid and the new
6550 in the prompt has I<two> dashes instead of one.
6552 We take the current list of pids and add this one to the end. If there
6553 isn't any list yet, we make one up out of the initial pid associated with
6554 the terminal and our new pid, sticking an arrow (either one-dashed or
6555 two dashed) in between them.
6557 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
6558 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
6563 sub resetterm { # We forked, so we need a different TTY
6565 # Needs to be passed to create_IN_OUT() as well.
6568 # resetterm(2): got in here because of a system() starting a debugger.
6569 # resetterm(1): just forked.
6570 my $systemed = $in > 1 ? '-' : '';
6572 # If there's already a list of pids, add this to the end.
6574 $pids =~ s/\]/$systemed->$$]/;
6577 # No pid list. Time to make one.
6579 $pids = "[$term_pid->$$]";
6582 # The prompt we're going to be using for this debugger.
6585 # We now 0wnz this terminal.
6588 # Just return if we're not supposed to try to create a new TTY.
6589 return unless $CreateTTY & $in;
6591 # Try to create a new IN/OUT pair.
6593 } ## end sub resetterm
6597 First, we handle stuff in the typeahead buffer. If there is any, we shift off
6598 the next line, print a message saying we got it, add it to the terminal
6599 history (if possible), and return it.
6601 If there's nothing in the typeahead buffer, check the command filehandle stack.
6602 If there are any filehandles there, read from the last one, and return the line
6603 if we got one. If not, we pop the filehandle off and close it, and try the
6604 next one up the stack.
6606 If we've emptied the filehandle stack, we check to see if we've got a socket
6607 open, and we read that and return it if we do. If we don't, we just call the
6608 core C<readline()> and return its value.
6614 # Localize to prevent it from being smashed in the program being debugged.
6617 # Pull a line out of the typeahead if there's stuff there.
6620 # How many lines left.
6621 my $left = @typeahead;
6623 # Get the next line.
6624 my $got = shift @typeahead;
6626 # Print a message saying we got input from the typeahead.
6628 print $OUT "auto(-$left)", shift, $got, "\n";
6630 # Add it to the terminal history (if possible).
6631 $term->AddHistory($got)
6633 and defined $term->Features->{addHistory};
6635 } ## end if (@typeahead)
6637 # We really need to read some input. Turn off entry/exit trace and
6638 # return value printing.
6642 # If there are stacked filehandles to read from ...
6645 # Read from the last one in the stack.
6646 my $line = CORE::readline( $cmdfhs[-1] );
6648 # If we got a line ...
6650 ? ( print $OUT ">> $line" and return $line ) # Echo and return
6651 : close pop @cmdfhs; # Pop and close
6652 } ## end while (@cmdfhs)
6654 # Nothing on the filehandle stack. Socket?
6655 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
6657 # Send anything we have to send.
6658 $OUT->write( join( '', @_ ) );
6660 # Receive anything there is to receive.
6665 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
6666 # XXX Don't know. You tell me.
6667 } while length $buf and ($stuff .= $buf) !~ /\n/;
6671 } ## end if (ref $OUT and UNIVERSAL::isa...
6673 # No socket. Just read from the terminal.
6675 $term->readline(@_);
6677 } ## end sub readline
6679 =head1 OPTIONS SUPPORT ROUTINES
6681 These routines handle listing and setting option values.
6683 =head2 C<dump_option> - list the current value of an option setting
6685 This routine uses C<option_val> to look up the value for an option.
6686 It cleans up escaped single-quotes and then displays the option and
6692 my ( $opt, $val ) = @_;
6693 $val = option_val( $opt, 'N/A' );
6694 $val =~ s/([\\\'])/\\$1/g;
6695 printf $OUT "%20s = '%s'\n", $opt, $val;
6696 } ## end sub dump_option
6698 sub options2remember {
6699 foreach my $k (@RememberOnROptions) {
6700 $option{$k} = option_val( $k, 'N/A' );
6705 =head2 C<option_val> - find the current value of an option
6707 This can't just be a simple hash lookup because of the indirect way that
6708 the option values are stored. Some are retrieved by calling a subroutine,
6709 some are just variables.
6711 You must supply a default value to be used in case the option isn't set.
6716 my ( $opt, $default ) = @_;
6719 # Does this option exist, and is it a variable?
6720 # If so, retrieve the value via the value in %optionVars.
6721 if ( defined $optionVars{$opt}
6722 and defined ${ $optionVars{$opt} } )
6724 $val = ${ $optionVars{$opt} };
6727 # Does this option exist, and it's a subroutine?
6728 # If so, call the subroutine via the ref in %optionAction
6729 # and capture the value.
6730 elsif ( defined $optionAction{$opt}
6731 and defined &{ $optionAction{$opt} } )
6733 $val = &{ $optionAction{$opt} }();
6736 # If there's an action or variable for the supplied option,
6737 # but no value was set, use the default.
6738 elsif (defined $optionAction{$opt} and not defined $option{$opt}
6739 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
6744 # Otherwise, do the simple hash lookup.
6746 $val = $option{$opt};
6749 # If the value isn't defined, use the default.
6750 # Then return whatever the value is.
6751 $val = $default unless defined $val;
6753 } ## end sub option_val
6755 =head2 C<parse_options>
6757 Handles the parsing and execution of option setting/displaying commands.
6759 An option entered by itself is assumed to be I<set me to 1> (the default value)
6760 if the option is a boolean one. If not, the user is prompted to enter a valid
6761 value or to query the current value (via C<option? >).
6763 If C<option=value> is entered, we try to extract a quoted string from the
6764 value (if it is quoted). If it's not, we just use the whole value as-is.
6766 We load any modules required to service this option, and then we set it: if
6767 it just gets stuck in a variable, we do that; if there's a subroutine to
6768 handle setting the option, we call that.
6770 Finally, if we're running in interactive mode, we display the effect of the
6771 user's command back to the terminal, skipping this if we're setting things
6772 during initialization.
6780 # These options need a value. Don't allow them to be clobbered by accident.
6781 my %opt_needs_val = map { ( $_ => 1 ) } qw{
6782 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
6783 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
6789 # Clean off excess leading whitespace.
6792 # Options are always all word characters, followed by a non-word
6794 s/^(\w+)(\W?)// or print( $OUT "Invalid option '$_'\n" ), last;
6795 my ( $opt, $sep ) = ( $1, $2 );
6797 # Make sure that such an option exists.
6798 my $matches = grep( /^\Q$opt/ && ( $option = $_ ), @options )
6799 || grep( /^\Q$opt/i && ( $option = $_ ), @options );
6801 print( $OUT "Unknown option '$opt'\n" ), next unless $matches;
6802 print( $OUT "Ambiguous option '$opt'\n" ), next if $matches > 1;
6805 # '?' as separator means query, but must have whitespace after it.
6806 if ( "?" eq $sep ) {
6807 print( $OUT "Option query '$opt?' followed by non-space '$_'\n" ),
6811 #&dump_option($opt);
6812 } ## end if ("?" eq $sep)
6814 # Separator is whitespace (or just a carriage return).
6815 # They're going for a default, which we assume is 1.
6816 elsif ( $sep !~ /\S/ ) {
6818 $val = "1"; # this is an evil default; make 'em set it!
6821 # Separator is =. Trying to set a value.
6822 elsif ( $sep eq "=" ) {
6824 # If quoted, extract a quoted string.
6825 if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
6827 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
6830 # Not quoted. Use the whole thing. Warn about 'option='.
6834 print OUT qq(Option better cleared using $opt=""\n)
6836 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
6838 } ## end elsif ($sep eq "=")
6840 # "Quoted" with [], <>, or {}.
6841 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
6843 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
6844 s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
6845 or print( $OUT "Unclosed option value '$opt$sep$_'\n" ), last;
6846 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
6847 } ## end else [ if ("?" eq $sep)
6849 # Exclude non-booleans from getting set to 1 by default.
6850 if ( $opt_needs_val{$option} && $val_defaulted ) {
6851 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
6853 "Option '$opt' is non-boolean. Use '$cmd $option=VAL' to set, '$cmd $option?' to query\n";
6855 } ## end if ($opt_needs_val{$option...
6857 # Save the option value.
6858 $option{$option} = $val if defined $val;
6860 # Load any module that this option requires.
6864 require '$optionRequire{$option}';
6866 } || die $@ # XXX: shouldn't happen
6867 if defined $optionRequire{$option}
6871 # Stick it in the proper variable if it goes in a variable.
6872 ${ $optionVars{$option} } = $val
6873 if defined $optionVars{$option}
6876 # Call the appropriate sub if it gets set via sub.
6877 &{ $optionAction{$option} }($val)
6878 if defined $optionAction{$option}
6879 && defined &{ $optionAction{$option} }
6882 # Not initialization - echo the value we set it to.
6883 dump_option($option) unless $OUT eq \*STDERR;
6884 } ## end while (length)
6885 } ## end sub parse_options
6887 =head1 RESTART SUPPORT
6889 These routines are used to store (and restore) lists of items in environment
6890 variables during a restart.
6894 Set_list packages up items to be stored in a set of environment variables
6895 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
6896 the values). Values outside the standard ASCII charset are stored by encoding
6897 then as hexadecimal values.
6902 my ( $stem, @list ) = @_;
6905 # VAR_n: how many we have. Scalar assignment gets the number of items.
6906 $ENV{"${stem}_n"} = @list;
6908 # Grab each item in the list, escape the backslashes, encode the non-ASCII
6909 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
6910 for $i ( 0 .. $#list ) {
6912 $val =~ s/\\/\\\\/g;
6913 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
6914 $ENV{"${stem}_$i"} = $val;
6915 } ## end for $i (0 .. $#list)
6916 } ## end sub set_list
6920 Reverse the set_list operation: grab VAR_n to see how many we should be getting
6921 back, and then pull VAR_0, VAR_1. etc. back out.
6928 my $n = delete $ENV{"${stem}_n"};
6930 for $i ( 0 .. $n - 1 ) {
6931 $val = delete $ENV{"${stem}_$i"};
6932 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
6936 } ## end sub get_list
6938 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
6942 The C<catch()> subroutine is the essence of fast and low-impact. We simply
6943 set an already-existing global scalar variable to a constant value. This
6944 avoids allocating any memory possibly in the middle of something that will
6945 get all confused if we do, particularly under I<unsafe signals>.
6951 return; # Put nothing on the stack - malloc/free land!
6956 C<warn> emits a warning, by joining together its arguments and printing
6957 them, with couple of fillips.
6959 If the composited message I<doesn't> end with a newline, we automatically
6960 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
6961 to be set to the filehandle to be used to output warnings; it makes no
6962 assumptions about what filehandles are available.
6967 my ($msg) = join( "", @_ );
6968 $msg .= ": $!\n" unless $msg =~ /\n$/;
6973 =head1 INITIALIZATION TTY SUPPORT
6975 =head2 C<reset_IN_OUT>
6977 This routine handles restoring the debugger's input and output filehandles
6978 after we've tried and failed to move them elsewhere. In addition, it assigns
6979 the debugger's output filehandle to $LINEINFO if it was already open there.
6984 my $switch_li = $LINEINFO eq $OUT;
6986 # If there's a term and it's able to get a new tty, try to get one.
6987 if ( $term and $term->Features->{newTTY} ) {
6988 ( $IN, $OUT ) = ( shift, shift );
6989 $term->newTTY( $IN, $OUT );
6992 # This term can't get a new tty now. Better luck later.
6994 &warn("Too late to set IN/OUT filehandles, enabled on next 'R'!\n");
6997 # Set the filehndles up as they were.
6999 ( $IN, $OUT ) = ( shift, shift );
7002 # Unbuffer the output filehandle.
7003 my $o = select $OUT;
7007 # Point LINEINFO to the same output filehandle if it was there before.
7008 $LINEINFO = $OUT if $switch_li;
7009 } ## end sub reset_IN_OUT
7011 =head1 OPTION SUPPORT ROUTINES
7013 The following routines are used to process some of the more complicated
7018 Sets the input and output filehandles to the specified files or pipes.
7019 If the terminal supports switching, we go ahead and do it. If not, and
7020 there's already a terminal in place, we save the information to take effect
7023 If there's no terminal yet (for instance, during debugger initialization),
7024 we go ahead and set C<$console> and C<$tty> to the file indicated.
7030 if ( @_ and $term and $term->Features->{newTTY} ) {
7032 # This terminal supports switching to a new TTY.
7033 # Can be a list of two files, or on string containing both names,
7035 # XXX Should this perhaps be an assignment from @_?
7036 my ( $in, $out ) = shift;
7039 # Split list apart if supplied.
7040 ( $in, $out ) = split /,/, $in, 2;
7044 # Use the same file for both input and output.
7048 # Open file onto the debugger's filehandles, if you can.
7049 open IN, $in or die "cannot open '$in' for read: $!";
7050 open OUT, ">$out" or die "cannot open '$out' for write: $!";
7052 # Swap to the new filehandles.
7053 reset_IN_OUT( \*IN, \*OUT );
7055 # Save the setting for later.
7057 } ## end if (@_ and $term and $term...
7059 # Terminal doesn't support new TTY, or doesn't support readline.
7060 # Can't do it now, try restarting.
7061 &warn("Too late to set TTY, enabled on next 'R'!\n") if $term and @_;
7063 # Useful if done through PERLDB_OPTS:
7064 $console = $tty = shift if @_;
7066 # Return whatever the TTY is.
7072 Sets the C<$notty> global, controlling whether or not the debugger tries to
7073 get a terminal to read from. If called after a terminal is already in place,
7074 we save the value to use it if we're restarted.
7080 &warn("Too late to set noTTY, enabled on next 'R'!\n") if @_;
7082 $notty = shift if @_;
7088 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
7089 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
7090 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
7091 the value in case a restart is done so we can change it then.
7097 &warn("Too late to set ReadLine, enabled on next 'R'!\n") if @_;
7101 } ## end sub ReadLine
7103 =head2 C<RemotePort>
7105 Sets the port that the debugger will try to connect to when starting up.
7106 If the terminal's already been set up, we can't do it, but we remember the
7107 setting in case the user does a restart.
7113 &warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
7115 $remoteport = shift if @_;
7117 } ## end sub RemotePort
7121 Checks with the terminal to see if C<Tk> is running, and returns true or
7122 false. Returns false if the current terminal doesn't support C<readline>.
7127 if ( ${ $term->Features }{tkRunning} ) {
7128 return $term->tkRunning(@_);
7132 print $OUT "tkRunning not supported by current ReadLine package.\n";
7135 } ## end sub tkRunning
7139 Sets nonstop mode. If a terminal's already been set up, it's too late; the
7140 debugger remembers the setting in case you restart, though.
7146 &warn("Too late to set up NonStop mode, enabled on next 'R'!\n")
7149 $runnonstop = shift if @_;
7151 } ## end sub NonStop
7155 &warn("Some flag changes could not take effect until next 'R'!\n")
7158 $^P = parse_DollarCaretP_flags(shift) if @_;
7159 expand_DollarCaretP_flags($^P);
7164 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
7172 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
7179 Sets the shell escape command, and generates a printable copy to be used
7186 # If we got an argument, meta-quote it, and add '\b' if it
7187 # ends in a word character.
7189 $sh = quotemeta shift;
7190 $sh .= "\\b" if $sh =~ /\w$/;
7193 # Generate the printable version for the help:
7194 $psh = $sh; # copy it
7195 $psh =~ s/\\b$//; # Take off trailing \b if any
7196 $psh =~ s/\\(.)/$1/g; # De-escape
7197 $psh; # return the printable version
7198 } ## end sub shellBang
7202 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7203 was passed as the argument. (This means you can't override the terminal's
7209 if ( defined $term ) {
7211 # We don't want to show warning backtraces, but we do want die() ones.
7212 local ( $warnLevel, $dieLevel ) = ( 0, 1 );
7214 # No ornaments if the terminal doesn't support them.
7215 return '' unless $term->Features->{ornaments};
7216 eval { $term->ornaments(@_) } || '';
7219 # Use what was passed in if we can't determine it ourselves.
7223 } ## end sub ornaments
7225 =head2 C<recallCommand>
7227 Sets the recall command, and builds a printable version which will appear in
7234 # If there is input, metaquote it. Add '\b' if it ends with a word
7237 $rc = quotemeta shift;
7238 $rc .= "\\b" if $rc =~ /\w$/;
7241 # Build it into a printable version.
7242 $prc = $rc; # Copy it
7243 $prc =~ s/\\b$//; # Remove trailing \b
7244 $prc =~ s/\\(.)/$1/g; # Remove escapes
7245 $prc; # Return the printable version
7246 } ## end sub recallCommand
7248 =head2 C<LineInfo> - where the line number information goes
7250 Called with no arguments, returns the file or pipe that line info should go to.
7252 Called with an argument (a file or a pipe), it opens that onto the
7253 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7254 file or pipe again to the caller.
7259 return $lineinfo unless @_;
7262 # If this is a valid "thing to be opened for output", tack a
7263 # '>' onto the front.
7264 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7266 # If this is a pipe, the stream points to a slave editor.
7267 $slave_editor = ( $stream =~ /^\|/ );
7269 # Open it up and unbuffer it.
7270 open( LINEINFO, "$stream" ) || &warn("Cannot open '$stream' for write");
7271 $LINEINFO = \*LINEINFO;
7272 my $save = select($LINEINFO);
7276 # Hand the file or pipe back again.
7278 } ## end sub LineInfo
7280 =head1 COMMAND SUPPORT ROUTINES
7282 These subroutines provide functionality for various commands.
7284 =head2 C<list_modules>
7286 For the C<M> command: list modules loaded and their versions.
7287 Essentially just runs through the keys in %INC, picks each package's
7288 C<$VERSION> variable, gets the file name, and formats the information
7293 sub list_modules { # versions
7297 # keys are the "as-loaded" name, values are the fully-qualified path
7298 # to the file itself.
7300 $file = $_; # get the module name
7301 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
7302 s,/,::,g; # change '/' to '::'
7303 s/^perl5db$/DB/; # Special case: debugger
7304 # moves to package DB
7305 s/^Term::ReadLine::readline$/readline/; # simplify readline
7307 # If the package has a $VERSION package global (as all good packages
7308 # should!) decode it and save as partial message.
7309 if ( defined ${ $_ . '::VERSION' } ) {
7310 $version{$file} = "${ $_ . '::VERSION' } from ";
7313 # Finish up the message with the file the package came from.
7314 $version{$file} .= $INC{$file};
7315 } ## end for (keys %INC)
7317 # Hey, dumpit() formats a hash nicely, so why not use it?
7318 dumpit( $OUT, \%version );
7319 } ## end sub list_modules
7323 Sets up the monster string used to format and print the help.
7325 =head3 HELP MESSAGE FORMAT
7327 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
7328 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
7329 easy to parse and portable, but which still allows the help to be a little
7330 nicer than just plain text.
7332 Essentially, you define the command name (usually marked up with C<< B<> >>
7333 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
7334 newline. The descriptive text can also be marked up in the same way. If you
7335 need to continue the descriptive text to another line, start that line with
7336 just tabs and then enter the marked-up text.
7338 If you are modifying the help text, I<be careful>. The help-string parser is
7339 not very sophisticated, and if you don't follow these rules it will mangle the
7340 help beyond hope until you fix the string.
7346 # XXX: make sure there are tabs between the command and explanation,
7347 # or print_help will screw up your formatting if you have
7348 # eeevil ornaments enabled. This is an insane mess.
7351 Help is currently only available for the new 5.8 command set.
7352 No help is available for the old command set.
7353 We assume you know what you're doing if you switch to it.
7356 B<s> [I<expr>] Single step [in I<expr>].
7357 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7358 <B<CR>> Repeat last B<n> or B<s> command.
7359 B<r> Return from current subroutine.
7360 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7361 at the specified position.
7362 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7363 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7364 B<l> I<line> List single I<line>.
7365 B<l> I<subname> List first window of lines from subroutine.
7366 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7367 B<l> List next window of lines.
7368 B<-> List previous window of lines.
7369 B<v> [I<line>] View window around I<line>.
7370 B<.> Return to the executed line.
7371 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7372 I<filename> may be either the full name of the file, or a regular
7373 expression matching the full file name:
7374 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7375 Evals (with saved bodies) are considered to be filenames:
7376 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7377 (in the order of execution).
7378 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7379 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7380 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
7381 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7382 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth).
7383 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
7384 B<b> Sets breakpoint on current line)
7385 B<b> [I<line>] [I<condition>]
7386 Set breakpoint; I<line> defaults to the current execution line;
7387 I<condition> breaks if it evaluates to true, defaults to '1'.
7388 B<b> I<subname> [I<condition>]
7389 Set breakpoint at first line of subroutine.
7390 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7391 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7392 B<b> B<postpone> I<subname> [I<condition>]
7393 Set breakpoint at first line of subroutine after
7395 B<b> B<compile> I<subname>
7396 Stop after the subroutine is compiled.
7397 B<B> [I<line>] Delete the breakpoint for I<line>.
7398 B<B> I<*> Delete all breakpoints.
7399 B<a> [I<line>] I<command>
7400 Set an action to be done before the I<line> is executed;
7401 I<line> defaults to the current execution line.
7402 Sequence is: check for breakpoint/watchpoint, print line
7403 if necessary, do action, prompt user if necessary,
7406 B<A> [I<line>] Delete the action for I<line>.
7407 B<A> I<*> Delete all actions.
7408 B<w> I<expr> Add a global watch-expression.
7410 B<W> I<expr> Delete a global watch-expression.
7411 B<W> I<*> Delete all watch-expressions.
7412 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7413 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7414 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7415 B<x> I<expr> Evals expression in list context, dumps the result.
7416 B<m> I<expr> Evals expression in list context, prints methods callable
7417 on the first element of the result.
7418 B<m> I<class> Prints methods callable via the given class.
7419 B<M> Show versions of loaded modules.
7420 B<i> I<class> Prints nested parents of given class.
7421 B<e> Display current thread id.
7422 B<E> Display all thread ids the current one will be identified: <n>.
7423 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7425 B<<> ? List Perl commands to run before each prompt.
7426 B<<> I<expr> Define Perl command to run before each prompt.
7427 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7428 B<< *> Delete the list of perl commands to run before each prompt.
7429 B<>> ? List Perl commands to run after each prompt.
7430 B<>> I<expr> Define Perl command to run after each prompt.
7431 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7432 B<>>B< *> Delete the list of Perl commands to run after each prompt.
7433 B<{> I<db_command> Define debugger command to run before each prompt.
7434 B<{> ? List debugger commands to run before each prompt.
7435 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7436 B<{ *> Delete the list of debugger commands to run before each prompt.
7437 B<$prc> I<number> Redo a previous command (default previous command).
7438 B<$prc> I<-number> Redo number'th-to-last command.
7439 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7440 See 'B<O> I<recallCommand>' too.
7441 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7446 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7448 See 'B<O> I<shellBang>' too.
7449 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7450 B<save> I<file> Save current debugger session (actual history) to I<file>.
7451 B<rerun> Rerun session to current position.
7452 B<rerun> I<n> Rerun session to numbered command.
7453 B<rerun> I<-n> Rerun session to number'th-to-last command.
7454 B<H> I<-number> Display last number commands (default all).
7455 B<H> I<*> Delete complete history.
7456 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7457 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7458 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarily select()ed as well.
7459 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7460 I<command> Execute as a perl statement in current package.
7461 B<R> Pure-man-restart of debugger, some of debugger state
7462 and command-line options may be lost.
7463 Currently the following settings are preserved:
7464 history, breakpoints and actions, debugger B<O>ptions
7465 and the following command-line options: I<-w>, I<-I>, I<-e>.
7467 B<o> [I<opt>] ... Set boolean option to true
7468 B<o> [I<opt>B<?>] Query options
7469 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7470 Set options. Use quotes if spaces in value.
7471 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7472 I<pager> program for output of \"|cmd\";
7473 I<tkRunning> run Tk while prompting (with ReadLine);
7474 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7475 I<inhibit_exit> Allows stepping off the end of the script.
7476 I<ImmediateStop> Debugger should stop as early as possible.
7477 I<RemotePort> Remote hostname:port for remote debugging
7478 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7479 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7480 I<compactDump>, I<veryCompact> change style of array and hash dump;
7481 I<globPrint> whether to print contents of globs;
7482 I<DumpDBFiles> dump arrays holding debugged files;
7483 I<DumpPackages> dump symbol tables of packages;
7484 I<DumpReused> dump contents of \"reused\" addresses;
7485 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7486 I<bareStringify> Do not print the overload-stringified value;
7487 Other options include:
7488 I<PrintRet> affects printing of return value after B<r> command,
7489 I<frame> affects printing messages on subroutine entry/exit.
7490 I<AutoTrace> affects printing messages on possible breaking points.
7491 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7492 I<ornaments> affects screen appearance of the command line.
7493 I<CreateTTY> bits control attempts to create a new TTY on events:
7494 1: on fork() 2: debugger is started inside debugger
7496 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7497 You can put additional initialization options I<TTY>, I<noTTY>,
7498 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7499 B<R> after you set them).
7501 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7502 B<h> Summary of debugger commands.
7503 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7504 B<h h> Long help for debugger commands
7505 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7506 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7507 Set B<\$DB::doccmd> to change viewer.
7509 Type '|h h' for a paged display if this was too hard to read.
7511 "; # Fix balance of vi % matching: }}}}
7513 # note: tabs in the following section are not-so-helpful
7514 $summary = <<"END_SUM";
7515 I<List/search source lines:> I<Control script execution:>
7516 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7517 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7518 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
7519 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7520 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7521 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
7522 I<Debugger controls:> B<L> List break/watch/actions
7523 B<o> [...] Set debugger options B<t> [I<n>] [I<expr>] Toggle trace [max depth] ][trace expr]
7524 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7525 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
7526 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7527 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
7528 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
7529 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
7530 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7531 B<q> or B<^D> Quit B<R> Attempt a restart
7532 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7533 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7534 B<p> I<expr> Print expression (uses script's current package).
7535 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7536 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7537 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
7538 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7539 B<e> Display thread id B<E> Display all thread ids.
7540 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7543 # ')}}; # Fix balance of vi % matching
7545 # and this is really numb...
7548 B<s> [I<expr>] Single step [in I<expr>].
7549 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7550 B<CR>> Repeat last B<n> or B<s> command.
7551 B<r> Return from current subroutine.
7552 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7553 at the specified position.
7554 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7555 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7556 B<l> I<line> List single I<line>.
7557 B<l> I<subname> List first window of lines from subroutine.
7558 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7559 B<l> List next window of lines.
7560 B<-> List previous window of lines.
7561 B<w> [I<line>] List window around I<line>.
7562 B<.> Return to the executed line.
7563 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7564 I<filename> may be either the full name of the file, or a regular
7565 expression matching the full file name:
7566 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7567 Evals (with saved bodies) are considered to be filenames:
7568 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7569 (in the order of execution).
7570 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7571 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7572 B<L> List all breakpoints and actions.
7573 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7574 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth) .
7575 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
7576 B<b> [I<line>] [I<condition>]
7577 Set breakpoint; I<line> defaults to the current execution line;
7578 I<condition> breaks if it evaluates to true, defaults to '1'.
7579 B<b> I<subname> [I<condition>]
7580 Set breakpoint at first line of subroutine.
7581 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7582 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7583 B<b> B<postpone> I<subname> [I<condition>]
7584 Set breakpoint at first line of subroutine after
7586 B<b> B<compile> I<subname>
7587 Stop after the subroutine is compiled.
7588 B<d> [I<line>] Delete the breakpoint for I<line>.
7589 B<D> Delete all breakpoints.
7590 B<a> [I<line>] I<command>
7591 Set an action to be done before the I<line> is executed;
7592 I<line> defaults to the current execution line.
7593 Sequence is: check for breakpoint/watchpoint, print line
7594 if necessary, do action, prompt user if necessary,
7596 B<a> [I<line>] Delete the action for I<line>.
7597 B<A> Delete all actions.
7598 B<W> I<expr> Add a global watch-expression.
7599 B<W> Delete all watch-expressions.
7600 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7601 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7602 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7603 B<x> I<expr> Evals expression in list context, dumps the result.
7604 B<m> I<expr> Evals expression in list context, prints methods callable
7605 on the first element of the result.
7606 B<m> I<class> Prints methods callable via the given class.
7608 B<<> ? List Perl commands to run before each prompt.
7609 B<<> I<expr> Define Perl command to run before each prompt.
7610 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7611 B<>> ? List Perl commands to run after each prompt.
7612 B<>> I<expr> Define Perl command to run after each prompt.
7613 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7614 B<{> I<db_command> Define debugger command to run before each prompt.
7615 B<{> ? List debugger commands to run before each prompt.
7616 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7617 B<$prc> I<number> Redo a previous command (default previous command).
7618 B<$prc> I<-number> Redo number'th-to-last command.
7619 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7620 See 'B<O> I<recallCommand>' too.
7621 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7626 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7628 See 'B<O> I<shellBang>' too.
7629 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7630 B<H> I<-number> Display last number commands (default all).
7631 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7632 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7633 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7634 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7635 I<command> Execute as a perl statement in current package.
7636 B<v> Show versions of loaded modules.
7637 B<R> Pure-man-restart of debugger, some of debugger state
7638 and command-line options may be lost.
7639 Currently the following settings are preserved:
7640 history, breakpoints and actions, debugger B<O>ptions
7641 and the following command-line options: I<-w>, I<-I>, I<-e>.
7643 B<O> [I<opt>] ... Set boolean option to true
7644 B<O> [I<opt>B<?>] Query options
7645 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7646 Set options. Use quotes if spaces in value.
7647 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7648 I<pager> program for output of \"|cmd\";
7649 I<tkRunning> run Tk while prompting (with ReadLine);
7650 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7651 I<inhibit_exit> Allows stepping off the end of the script.
7652 I<ImmediateStop> Debugger should stop as early as possible.
7653 I<RemotePort> Remote hostname:port for remote debugging
7654 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7655 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7656 I<compactDump>, I<veryCompact> change style of array and hash dump;
7657 I<globPrint> whether to print contents of globs;
7658 I<DumpDBFiles> dump arrays holding debugged files;
7659 I<DumpPackages> dump symbol tables of packages;
7660 I<DumpReused> dump contents of \"reused\" addresses;
7661 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7662 I<bareStringify> Do not print the overload-stringified value;
7663 Other options include:
7664 I<PrintRet> affects printing of return value after B<r> command,
7665 I<frame> affects printing messages on subroutine entry/exit.
7666 I<AutoTrace> affects printing messages on possible breaking points.
7667 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7668 I<ornaments> affects screen appearance of the command line.
7669 I<CreateTTY> bits control attempts to create a new TTY on events:
7670 1: on fork() 2: debugger is started inside debugger
7672 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7673 You can put additional initialization options I<TTY>, I<noTTY>,
7674 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7675 B<R> after you set them).
7677 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7678 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7679 B<h h> Summary of debugger commands.
7680 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7681 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7682 Set B<\$DB::doccmd> to change viewer.
7684 Type '|h' for a paged display if this was too hard to read.
7686 "; # Fix balance of vi % matching: }}}}
7688 # note: tabs in the following section are not-so-helpful
7689 $pre580_summary = <<"END_SUM";
7690 I<List/search source lines:> I<Control script execution:>
7691 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7692 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7693 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
7694 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7695 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7696 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
7697 I<Debugger controls:> B<L> List break/watch/actions
7698 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7699 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7700 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
7701 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7702 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
7703 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
7704 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7705 B<q> or B<^D> Quit B<R> Attempt a restart
7706 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7707 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7708 B<p> I<expr> Print expression (uses script's current package).
7709 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7710 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7711 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
7712 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7713 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7716 # ')}}; # Fix balance of vi % matching
7718 } ## end sub sethelp
7720 =head2 C<print_help()>
7722 Most of what C<print_help> does is just text formatting. It finds the
7723 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
7724 terminal control characters to simulate them (courtesy of
7725 C<Term::ReadLine::TermCap>).
7732 # Restore proper alignment destroyed by eeevil I<> and B<>
7733 # ornaments: A pox on both their houses!
7735 # A help command will have everything up to and including
7736 # the first tab sequence padded into a field 16 (or if indented 20)
7737 # wide. If it's wider than that, an extra space will be added.
7739 ^ # only matters at start of line
7740 ( \040{4} | \t )* # some subcommands are indented
7741 ( < ? # so <CR> works
7742 [BI] < [^\t\n] + ) # find an eeevil ornament
7743 ( \t+ ) # original separation, discarded
7744 ( .* ) # this will now start (no earlier) than
7747 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
7748 my $clean = $command;
7749 $clean =~ s/[BI]<([^>]*)>/$1/g;
7751 # replace with this whole string:
7752 ($leadwhite ? " " x 4 : "")
7754 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
7759 s{ # handle bold ornaments
7760 B < ( [^>] + | > ) >
7762 $Term::ReadLine::TermCap::rl_term_set[2]
7764 . $Term::ReadLine::TermCap::rl_term_set[3]
7767 s{ # handle italic ornaments
7768 I < ( [^>] + | > ) >
7770 $Term::ReadLine::TermCap::rl_term_set[0]
7772 . $Term::ReadLine::TermCap::rl_term_set[1]
7777 } ## end sub print_help
7781 This routine does a lot of gyrations to be sure that the pager is C<less>.
7782 It checks for C<less> masquerading as C<more> and records the result in
7783 C<$fixed_less> so we don't have to go through doing the stats again.
7789 # We already know if this is set.
7790 return if $fixed_less;
7792 # Pager is less for sure.
7793 my $is_less = $pager =~ /\bless\b/;
7794 if ( $pager =~ /\bmore\b/ ) {
7796 # Nope, set to more. See what's out there.
7797 my @st_more = stat('/usr/bin/more');
7798 my @st_less = stat('/usr/bin/less');
7800 # is it really less, pretending to be more?
7803 && $st_more[0] == $st_less[0]
7804 && $st_more[1] == $st_less[1];
7805 } ## end if ($pager =~ /\bmore\b/)
7807 # changes environment!
7808 # 'r' added so we don't do (slow) stats again.
7809 $fixed_less = 1 if $is_less;
7810 } ## end sub fix_less
7812 =head1 DIE AND WARN MANAGEMENT
7816 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
7817 to debug a debugger problem.
7819 It does its best to report the error that occurred, and then forces the
7820 program, debugger, and everything to die.
7826 # No entry/exit messages.
7829 # No return value prints.
7832 # set the abort signal handling to the default (just terminate).
7833 $SIG{'ABRT'} = 'DEFAULT';
7835 # If we enter the signal handler recursively, kill myself with an
7836 # abort signal (so we just terminate).
7837 kill 'ABRT', $$ if $panic++;
7839 # If we can show detailed info, do so.
7840 if ( defined &Carp::longmess ) {
7842 # Don't recursively enter the warn handler, since we're carping.
7843 local $SIG{__WARN__} = '';
7845 # Skip two levels before reporting traceback: we're skipping
7846 # mydie and confess.
7847 local $Carp::CarpLevel = 2; # mydie + confess
7849 # Tell us all about it.
7850 &warn( Carp::longmess("Signal @_") );
7853 # No Carp. Tell us about the signal as best we can.
7856 print $DB::OUT "Got signal @_\n";
7861 } ## end sub diesignal
7865 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
7866 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
7872 # No entry/exit trace.
7875 # No return value printing.
7878 # Turn off warn and die handling to prevent recursive entries to this
7880 local $SIG{__WARN__} = '';
7881 local $SIG{__DIE__} = '';
7883 # Load Carp if we can. If $^S is false (current thing being compiled isn't
7884 # done yet), we may not be able to do a require.
7885 eval { require Carp }
7886 if defined $^S; # If error/warning during compilation,
7887 # require may be broken.
7889 # Use the core warn() unless Carp loaded OK.
7891 "\nCannot print stack trace, load with -MCarp option to see stack" ),
7893 unless defined &Carp::longmess;
7895 # Save the current values of $single and $trace, and then turn them off.
7896 my ( $mysingle, $mytrace ) = ( $single, $trace );
7900 # We can call Carp::longmess without its being "debugged" (which we
7901 # don't want - we just want to use it!). Capture this for later.
7902 my $mess = Carp::longmess(@_);
7904 # Restore $single and $trace to their original values.
7905 ( $single, $trace ) = ( $mysingle, $mytrace );
7907 # Use the debugger's own special way of printing warnings to print
7908 # the stack trace message.
7914 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
7915 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
7916 single stepping and tracing during the call to C<Carp::longmess> to avoid
7917 debugging it - we just want to use it.
7919 If C<dieLevel> is zero, we let the program being debugged handle the
7920 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
7921 the debugger takes over all exception handling, printing a backtrace and
7922 displaying the exception via its C<dbwarn()> routine.
7929 local $SIG{__DIE__} = '';
7930 local $SIG{__WARN__} = '';
7934 if ( $dieLevel > 2 ) {
7935 local $SIG{__WARN__} = \&dbwarn;
7936 &warn(@_); # Yell no matter what
7939 if ( $dieLevel < 2 ) {
7940 die @_ if $^S; # in eval propagate
7943 # The code used to check $^S to see if compilation of the current thing
7944 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
7945 eval { require Carp };
7948 "\nCannot print stack trace, load with -MCarp option to see stack" )
7949 unless defined &Carp::longmess;
7951 # We do not want to debug this chunk (automatic disabling works
7952 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
7953 # get the stack trace from Carp::longmess (if possible), restore $signal
7954 # and $trace, and then die with the stack trace.
7955 my ( $mysingle, $mytrace ) = ( $single, $trace );
7961 package Carp; # Do not include us in the list
7962 eval { $mess = Carp::longmess(@_); };
7964 ( $single, $trace ) = ( $mysingle, $mytrace );
7968 =head2 C<warnlevel()>
7970 Set the C<$DB::warnLevel> variable that stores the value of the
7971 C<warnLevel> option. Calling C<warnLevel()> with a positive value
7972 results in the debugger taking over all warning handlers. Setting
7973 C<warnLevel> to zero leaves any warning handlers set up by the program
7974 being debugged in place.
7980 $prevwarn = $SIG{__WARN__} unless $warnLevel;
7983 $SIG{__WARN__} = \&DB::dbwarn;
7986 $SIG{__WARN__} = $prevwarn;
7988 undef $SIG{__WARN__};
7992 } ## end sub warnLevel
7996 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
7997 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
7998 zero lets you use your own C<die()> handler.
8005 $prevdie = $SIG{__DIE__} unless $dieLevel;
8009 # Always set it to dbdie() for non-zero values.
8010 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
8012 # No longer exists, so don't try to use it.
8013 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
8015 # If we've finished initialization, mention that stack dumps
8016 # are enabled, If dieLevel is 1, we won't stack dump if we die
8018 print $OUT "Stack dump during die enabled",
8019 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
8022 # XXX This is probably obsolete, given that diehard() is gone.
8023 print $OUT "Dump printed too.\n" if $dieLevel > 2;
8024 } ## end if ($dieLevel)
8026 # Put the old one back if there was one.
8028 $SIG{__DIE__} = $prevdie;
8029 print $OUT "Default die handler restored.\n";
8031 undef $SIG{__DIE__};
8032 print $OUT "Die handler removed.\n";
8036 } ## end sub dieLevel
8038 =head2 C<signalLevel>
8040 Number three in a series: set C<signalLevel> to zero to keep your own
8041 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
8042 takes over and handles them with C<DB::diesignal()>.
8048 $prevsegv = $SIG{SEGV} unless $signalLevel;
8049 $prevbus = $SIG{BUS} unless $signalLevel;
8050 $signalLevel = shift;
8052 $SIG{SEGV} = \&DB::diesignal;
8053 $SIG{BUS} = \&DB::diesignal;
8056 $SIG{SEGV} = $prevsegv;
8057 $SIG{BUS} = $prevbus;
8061 } ## end sub signalLevel
8063 =head1 SUBROUTINE DECODING SUPPORT
8065 These subroutines are used during the C<x> and C<X> commands to try to
8066 produce as much information as possible about a code reference. They use
8067 L<Devel::Peek> to try to find the glob in which this code reference lives
8068 (if it does) - this allows us to actually code references which correspond
8069 to named subroutines (including those aliased via glob assignment).
8071 =head2 C<CvGV_name()>
8073 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
8074 via that routine. If this fails, return the reference again (when the
8075 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
8081 my $name = CvGV_name_or_bust($in);
8082 defined $name ? $name : $in;
8085 =head2 C<CvGV_name_or_bust> I<coderef>
8087 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
8088 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
8089 find a glob for this ref.
8091 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
8095 sub CvGV_name_or_bust {
8097 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
8098 return unless ref $in;
8099 $in = \&$in; # Hard reference...
8100 eval { require Devel::Peek; 1 } or return;
8101 my $gv = Devel::Peek::CvGV($in) or return;
8102 *$gv{PACKAGE} . '::' . *$gv{NAME};
8103 } ## end sub CvGV_name_or_bust
8107 A utility routine used in various places; finds the file where a subroutine
8108 was defined, and returns that filename and a line-number range.
8110 Tries to use C<@sub> first; if it can't find it there, it tries building a
8111 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
8112 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
8113 this way, it brute-force searches C<%sub>, checking for identical references.
8120 return unless defined &$subr;
8121 my $name = CvGV_name_or_bust($subr);
8123 $data = $sub{$name} if defined $name;
8124 return $data if defined $data;
8127 $subr = \&$subr; # Hard reference
8130 $s = $_, last if $subr eq \&$_;
8134 } ## end sub find_sub
8138 A subroutine that uses the utility function C<methods_via> to find all the
8139 methods in the class corresponding to the current reference and in
8146 # Figure out the class - either this is the class or it's a reference
8147 # to something blessed into that class.
8149 $class = ref $class if ref $class;
8153 # Show the methods that this class has.
8154 methods_via( $class, '', 1 );
8156 # Show the methods that UNIVERSAL has.
8157 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
8158 } ## end sub methods
8160 =head2 C<methods_via($class, $prefix, $crawl_upward)>
8162 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
8163 all the parent class methods. C<$class> is the name of the next class to
8164 try; C<$prefix> is the message prefix, which gets built up as we go up the
8165 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
8166 higher in the C<@ISA> tree, 0 if we should stop.
8172 # If we've processed this class already, just quit.
8174 return if $seen{$class}++;
8176 # This is a package that is contributing the methods we're about to print.
8178 my $prepend = $prefix ? "via $prefix: " : '';
8181 # Extract from all the symbols in this class.
8182 while (my ($name, $glob) = each %{"${class}::"}) {
8183 # references directly in the symbol table are Proxy Constant
8184 # Subroutines, and are by their very nature defined
8185 # Otherwise, check if the thing is a typeglob, and if it is, it decays
8186 # to a subroutine reference, which can be tested by defined.
8187 # $glob might also be the value -1 (from sub foo;)
8188 # or (say) '$$' (from sub foo ($$);)
8189 # \$glob will be SCALAR in both cases.
8190 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob))
8191 && !$seen{$name}++) {
8192 push @to_print, "$prepend$name\n";
8199 print $DB::OUT $_ foreach sort @to_print;
8202 # If the $crawl_upward argument is false, just quit here.
8203 return unless shift;
8205 # $crawl_upward true: keep going up the tree.
8206 # Find all the classes this one is a subclass of.
8207 for $name ( @{"${class}::ISA"} ) {
8209 # Set up the new prefix.
8210 $prepend = $prefix ? $prefix . " -> $name" : $name;
8212 # Crawl up the tree and keep trying to crawl up.
8213 methods_via( $name, $prepend, 1 );
8215 } ## end sub methods_via
8217 =head2 C<setman> - figure out which command to use to show documentation
8219 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8224 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|NetWare)\z/s
8225 ? "man" # O Happy Day!
8226 : "perldoc"; # Alas, poor unfortunates
8229 =head2 C<runman> - run the appropriate command to show documentation
8231 Accepts a man page name; runs the appropriate command to display it (set up
8232 during debugger initialization). Uses C<DB::system> to avoid mucking up the
8233 program's STDIN and STDOUT.
8240 &system("$doccmd $doccmd");
8244 # this way user can override, like with $doccmd="man -Mwhatever"
8245 # or even just "man " to disable the path check.
8246 unless ( $doccmd eq 'man' ) {
8247 &system("$doccmd $page");
8251 $page = 'perl' if lc($page) eq 'help';
8254 my $man1dir = $Config::Config{'man1dir'};
8255 my $man3dir = $Config::Config{'man3dir'};
8256 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
8258 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
8259 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
8260 chop $manpath if $manpath;
8262 # harmless if missing, I figure
8263 my $oldpath = $ENV{MANPATH};
8264 $ENV{MANPATH} = $manpath if $manpath;
8265 my $nopathopt = $^O =~ /dunno what goes here/;
8270 # I just *know* there are men without -M
8271 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8276 unless ( $page =~ /^perl\w/ ) {
8277 # do it this way because its easier to slurp in to keep up to date - clunky though.
8412 if (grep { $page eq $_ } @pods) {
8414 CORE::system( $doccmd,
8415 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8417 } ## end if (grep { $page eq $_...
8418 } ## end unless ($page =~ /^perl\w/)
8419 } ## end if (CORE::system($doccmd...
8420 if ( defined $oldpath ) {
8421 $ENV{MANPATH} = $manpath;
8424 delete $ENV{MANPATH};
8428 #use Carp; # This did break, left for debugging
8430 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
8432 Because of the way the debugger interface to the Perl core is designed, any
8433 debugger package globals that C<DB::sub()> requires have to be defined before
8434 any subroutines can be called. These are defined in the second C<BEGIN> block.
8436 This block sets things up so that (basically) the world is sane
8437 before the debugger starts executing. We set up various variables that the
8438 debugger has to have set up before the Perl core starts running:
8444 The debugger's own filehandles (copies of STD and STDOUT for now).
8448 Characters for shell escapes, the recall command, and the history command.
8452 The maximum recursion depth.
8456 The size of a C<w> command's window.
8460 The before-this-line context to be printed in a C<v> (view a window around this line) command.
8464 The fact that we're not in a sub at all right now.
8468 The default SIGINT handler for the debugger.
8472 The appropriate value of the flag in C<$^D> that says the debugger is running
8476 The current debugger recursion level
8480 The list of postponed items and the C<$single> stack (XXX define this)
8484 That we want no return values and no subroutine entry/exit trace.
8490 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
8492 BEGIN { # This does not compile, alas. (XXX eh?)
8493 $IN = \*STDIN; # For bugs before DB::OUT has been opened
8494 $OUT = \*STDERR; # For errors before DB::OUT has been opened
8496 # Define characters used by command parsing.
8497 $sh = '!'; # Shell escape (does not work)
8498 $rc = ','; # Recall command (does not work)
8499 @hist = ('?'); # Show history (does not work)
8500 @truehist = (); # Can be saved for replay (per session)
8502 # This defines the point at which you get the 'deep recursion'
8503 # warning. It MUST be defined or the debugger will not load.
8506 # Number of lines around the current one that are shown in the
8510 # How much before-the-current-line context the 'v' command should
8511 # use in calculating the start of the window it will display.
8514 # We're not in any sub yet, but we need this to be a defined value.
8517 # Set up the debugger's interrupt handler. It simply sets a flag
8518 # ($signal) that DB::DB() will check before each command is executed.
8519 $SIG{INT} = \&DB::catch;
8521 # The following lines supposedly, if uncommented, allow the debugger to
8522 # debug itself. Perhaps we can try that someday.
8523 # This may be enabled to debug debugger:
8524 #$warnLevel = 1 unless defined $warnLevel;
8525 #$dieLevel = 1 unless defined $dieLevel;
8526 #$signalLevel = 1 unless defined $signalLevel;
8528 # This is the flag that says "a debugger is running, please call
8529 # DB::DB and DB::sub". We will turn it on forcibly before we try to
8530 # execute anything in the user's context, because we always want to
8532 $db_stop = 0; # Compiler warning ...
8533 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
8535 # This variable records how many levels we're nested in debugging. Used
8536 # Used in the debugger prompt, and in determining whether it's all over or
8538 $level = 0; # Level of recursive debugging
8540 # "Triggers bug (?) in perl if we postpone this until runtime."
8541 # XXX No details on this yet, or whether we should fix the bug instead
8542 # of work around it. Stay tuned.
8543 @postponed = @stack = (0);
8545 # Used to track the current stack depth using the auto-stacked-variable
8547 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
8549 # Don't print return values on exiting a subroutine.
8552 # No extry/exit tracing.
8557 BEGIN { $^W = $ini_warn; } # Switch warnings back
8559 =head1 READLINE SUPPORT - COMPLETION FUNCTION
8563 C<readline> support - adds command completion to basic C<readline>.
8565 Returns a list of possible completions to C<readline> when invoked. C<readline>
8566 will print the longest common substring following the text already entered.
8568 If there is only a single possible completion, C<readline> will use it in full.
8570 This code uses C<map> and C<grep> heavily to create lists of possible
8571 completion. Think LISP in this section.
8577 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
8578 # $text is the text to be completed.
8579 # $line is the incoming line typed by the user.
8580 # $start is the start of the text to be completed in the incoming line.
8581 my ( $text, $line, $start ) = @_;
8583 # Save the initial text.
8584 # The search pattern is current package, ::, extract the next qualifier
8585 # Prefix and pack are set to undef.
8586 my ( $itext, $search, $prefix, $pack ) =
8587 ( $text, "^\Q${'package'}::\E([^:]+)\$" );
8589 =head3 C<b postpone|compile>
8595 Find all the subroutines that might match in this package
8599 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
8603 Include all the rest of the subs that are known
8607 C<grep> out the ones that match the text we have so far
8611 Return this as the list of possible completions
8617 return sort grep /^\Q$text/, ( keys %sub ),
8618 qw(postpone load compile), # subroutines
8619 ( map { /$search/ ? ($1) : () } keys %sub )
8620 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
8624 Get all the possible files from C<@INC> as it currently stands and
8625 select the ones that match the text so far.
8629 return sort grep /^\Q$text/, values %INC # files
8630 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
8632 =head3 C<V> (list variable) and C<m> (list modules)
8634 There are two entry points for these commands:
8636 =head4 Unqualified package names
8638 Get the top-level packages and grab everything that matches the text
8639 so far. For each match, recursively complete the partial packages to
8640 get all possible matching packages. Return this sorted list.
8644 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8645 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
8646 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
8648 =head4 Qualified package names
8650 Take a partially-qualified package and find all subpackages for it
8651 by getting all the subpackages for the package so far, matching all
8652 the subpackages against the text, and discarding all of them which
8653 start with 'main::'. Return this list.
8657 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8658 grep !/^main::/, grep /^\Q$text/,
8659 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () } keys %{ $prefix . '::' }
8660 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
8661 and $text =~ /^(.*[^:])::?(\w*)$/
8664 =head3 C<f> - switch files
8666 Here, we want to get a fully-qualified filename for the C<f> command.
8671 =item 1. The original source file itself
8673 =item 2. A file from C<@INC>
8675 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
8681 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
8682 # We might possibly want to switch to an eval (which has a "filename"
8683 # like '(eval 9)'), so we may need to clean up the completion text
8684 # before proceeding.
8685 $prefix = length($1) - length($text);
8690 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
8691 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
8692 out of C<%main::>, add the initial source file, and extract the ones that
8693 match the completion text so far.
8698 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
8700 } ## end if ($line =~ /^\|*f\s+(.*)/)
8702 =head3 Subroutine name completion
8704 We look through all of the defined subs (the keys of C<%sub>) and
8705 return both all the possible matches to the subroutine name plus
8706 all the matches qualified to the current package.
8710 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
8711 $text = substr $text, 1;
8713 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
8715 map { /$search/ ? ($1) : () }
8718 } ## end if ((substr $text, 0, ...
8720 =head3 Scalar, array, and hash completion: partially qualified package
8722 Much like the above, except we have to do a little more cleanup:
8726 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
8734 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
8738 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
8744 Figure out the prefix vs. what needs completing.
8748 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
8755 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
8759 my @out = map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
8766 If there's only one hit, and it's a package qualifier, and it's not equal to the initial text, re-complete it using the symbol we actually found.
8770 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8771 return db_complete( $out[0], $line, $start );
8774 # Return the list of possibles.
8777 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
8783 =head3 Symbol completion: current package or package C<main>.
8787 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
8794 If it's C<main>, delete main to just get C<::> leading.
8798 $pack = ( $package eq 'main' ? '' : $package ) . '::';
8804 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
8808 $prefix = substr $text, 0, 1;
8809 $text = substr $text, 1;
8817 We look for the lexical scope above DB::DB and auto-complete lexical variables
8818 if PadWalker could be loaded.
8822 if (not $text =~ /::/ and eval { require PadWalker } ) {
8825 my @info = caller($level);
8829 last if $info[3] eq 'DB::DB';
8832 my $lexicals = PadWalker::peek_my($level);
8833 push @out, grep /^\Q$prefix$text/, keys %$lexicals;
8841 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
8845 push @out, map "$prefix$_", grep /^\Q$text/,
8846 ( grep /^_?[a-zA-Z]/, keys %$pack ),
8847 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
8851 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
8857 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8858 return db_complete( $out[0], $line, $start );
8861 # Return the list of possibles.
8863 } ## end if ($text =~ /^[\$@%]/)
8867 We use C<option_val()> to look up the current value of the option. If there's
8868 only a single value, we complete the command in such a way that it is a
8869 complete command for setting the option in question. If there are multiple
8870 possible values, we generate a command consisting of the option plus a trailing
8871 question mark, which, if executed, will list the current value of the option.
8875 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
8876 { # Options after space
8877 # We look for the text to be matched in the list of possible options,
8878 # and fetch the current value.
8879 my @out = grep /^\Q$text/, @options;
8880 my $val = option_val( $out[0], undef );
8882 # Set up a 'query option's value' command.
8884 if ( not defined $val or $val =~ /[\n\r]/ ) {
8886 # There's really nothing else we can do.
8889 # We have a value. Create a proper option-setting command.
8890 elsif ( $val =~ /\s/ ) {
8892 # XXX This may be an extraneous variable.
8895 # We'll want to quote the string (because of the embedded
8896 # whtespace), but we want to make sure we don't end up with
8897 # mismatched quote characters. We try several possibilities.
8898 foreach $l ( split //, qq/\"\'\#\|/ ) {
8900 # If we didn't find this quote character in the value,
8901 # quote it using this quote character.
8902 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
8904 } ## end elsif ($val =~ /\s/)
8906 # Don't need any quotes.
8911 # If there were multiple possible values, return '? ', which
8912 # makes the command into a query command. If there was just one,
8913 # have readline append that.
8914 $rl_attribs->{completer_terminator_character} =
8915 ( @out == 1 ? $out : '? ' );
8917 # Return list of possibilities.
8919 } ## end if ((substr $line, 0, ...
8921 =head3 Filename completion
8923 For entering filenames. We simply call C<readline>'s C<filename_list()>
8924 method with the completion text to get the possible completions.
8928 return $term->filename_list($text); # filenames
8930 } ## end sub db_complete
8932 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
8934 Functions that possibly ought to be somewhere else.
8944 print $OUT "Use 'q' to quit or 'R' to restart. 'h q' for details.\n";
8949 If we have $ini_pids, save it in the environment; else remove it from the
8950 environment. Used by the C<R> (restart) command.
8955 if ( defined($ini_pids) ) {
8956 $ENV{PERLDB_PIDS} = $ini_pids;
8959 delete( $ENV{PERLDB_PIDS} );
8961 } ## end sub clean_ENV
8963 # PERLDBf_... flag names from perl.h
8964 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
8967 %DollarCaretP_flags = (
8968 PERLDBf_SUB => 0x01, # Debug sub enter/exit
8969 PERLDBf_LINE => 0x02, # Keep line #
8970 PERLDBf_NOOPT => 0x04, # Switch off optimizations
8971 PERLDBf_INTER => 0x08, # Preserve more data
8972 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
8973 PERLDBf_SINGLE => 0x20, # Start with single-step on
8974 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
8975 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
8976 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
8977 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
8978 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"}
8979 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO
8981 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger
8982 # doesn't need to set it. It's provided for the benefit of profilers and
8983 # other code analysers.
8985 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
8988 sub parse_DollarCaretP_flags {
8993 foreach my $f ( split /\s*\|\s*/, $flags ) {
8995 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
8998 elsif ( $f =~ /^(\d+)$/ ) {
9001 elsif ( $f =~ /^DEFAULT$/i ) {
9002 $value = $DollarCaretP_flags{PERLDB_ALL};
9005 $f =~ /^(?:PERLDBf_)?(.*)$/i;
9006 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
9007 unless ( defined $value ) {
9009 "Unrecognized \$^P flag '$f'!\n",
9010 "Acceptable flags are: "
9011 . join( ', ', sort keys %DollarCaretP_flags ),
9012 ", and hexadecimal and decimal numbers.\n"
9022 sub expand_DollarCaretP_flags {
9023 my $DollarCaretP = shift;
9026 my $n = ( 1 << $_ );
9027 ( $DollarCaretP & $n )
9028 ? ( $DollarCaretP_flags_r{$n}
9029 || sprintf( '0x%x', $n ) )
9033 return @bits ? join( '|', @bits ) : 0;
9040 Rerun the current session to:
9042 rerun current position
9044 rerun 4 command number 4
9046 rerun -4 current command minus 4 (go back 4 steps)
9048 Whether this always makes sense, in the current context is unknowable, and is
9049 in part left as a useful exercise for the reader. This sub returns the
9050 appropriate arguments to rerun the current session.
9057 pop(@truehist); # strim
9058 unless (defined $truehist[$i]) {
9059 print "Unable to return to non-existent command: $i\n";
9061 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
9062 my @temp = @truehist; # store
9063 push(@DB::typeahead, @truehist); # saved
9064 @truehist = @hist = (); # flush
9065 @args = &restart(); # setup
9066 &get_list("PERLDB_HIST"); # clean
9067 &set_list("PERLDB_HIST", @temp); # reset
9074 Restarting the debugger is a complex operation that occurs in several phases.
9075 First, we try to reconstruct the command line that was used to invoke Perl
9081 # I may not be able to resurrect you, but here goes ...
9083 "Warning: some settings and command-line options may be lost!\n";
9084 my ( @script, @flags, $cl );
9086 # If warn was on before, turn it on again.
9087 push @flags, '-w' if $ini_warn;
9089 # Rebuild the -I flags that were on the initial
9092 push @flags, '-I', $_;
9095 # Turn on taint if it was on before.
9096 push @flags, '-T' if ${^TAINT};
9098 # Arrange for setting the old INC:
9099 # Save the current @init_INC in the environment.
9100 set_list( "PERLDB_INC", @ini_INC );
9102 # If this was a perl one-liner, go to the "file"
9103 # corresponding to the one-liner read all the lines
9104 # out of it (except for the first one, which is going
9105 # to be added back on again when 'perl -d' runs: that's
9106 # the 'require perl5db.pl;' line), and add them back on
9107 # to the command line to be executed.
9109 for ( 1 .. $#{'::_<-e'} ) { # The first line is PERL5DB
9110 chomp( $cl = ${'::_<-e'}[$_] );
9111 push @script, '-e', $cl;
9113 } ## end if ($0 eq '-e')
9115 # Otherwise we just reuse the original name we had
9123 After the command line has been reconstructed, the next step is to save
9124 the debugger's status in environment variables. The C<DB::set_list> routine
9125 is used to save aggregate variables (both hashes and arrays); scalars are
9126 just popped into environment variables directly.
9130 # If the terminal supported history, grab it and
9131 # save that in the environment.
9132 set_list( "PERLDB_HIST",
9133 $term->Features->{getHistory}
9137 # Find all the files that were visited during this
9138 # session (i.e., the debugger had magic hashes
9139 # corresponding to them) and stick them in the environment.
9140 my @had_breakpoints = keys %had_breakpoints;
9141 set_list( "PERLDB_VISITED", @had_breakpoints );
9143 # Save the debugger options we chose.
9144 set_list( "PERLDB_OPT", %option );
9145 # set_list( "PERLDB_OPT", options2remember() );
9147 # Save the break-on-loads.
9148 set_list( "PERLDB_ON_LOAD", %break_on_load );
9152 The most complex part of this is the saving of all of the breakpoints. They
9153 can live in an awful lot of places, and we have to go through all of them,
9154 find the breakpoints, and then save them in the appropriate environment
9155 variable via C<DB::set_list>.
9159 # Go through all the breakpoints and make sure they're
9162 for ( 0 .. $#had_breakpoints ) {
9164 # We were in this file.
9165 my $file = $had_breakpoints[$_];
9167 # Grab that file's magic line hash.
9168 *dbline = $main::{ '_<' . $file };
9170 # Skip out if it doesn't exist, or if the breakpoint
9171 # is in a postponed file (we'll do postponed ones
9173 next unless %dbline or $postponed_file{$file};
9175 # In an eval. This is a little harder, so we'll
9176 # do more processing on that below.
9177 ( push @hard, $file ), next
9178 if $file =~ /^\(\w*eval/;
9180 # XXX I have no idea what this is doing. Yet.
9182 @add = %{ $postponed_file{$file} }
9183 if $postponed_file{$file};
9185 # Save the list of all the breakpoints for this file.
9186 set_list( "PERLDB_FILE_$_", %dbline, @add );
9188 # Serialize the extra data %breakpoints_data hash.
9190 set_list( "PERLDB_FILE_ENABLED_$_",
9191 map { _is_breakpoint_enabled($file, $_) ? 1 : 0 }
9192 sort { $a <=> $b } keys(%dbline)
9194 } ## end for (0 .. $#had_breakpoints)
9196 # The breakpoint was inside an eval. This is a little
9197 # more difficult. XXX and I don't understand it.
9199 # Get over to the eval in question.
9200 *dbline = $main::{ '_<' . $_ };
9201 my ( $quoted, $sub, %subs, $line ) = quotemeta $_;
9202 for $sub ( keys %sub ) {
9203 next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/;
9204 $subs{$sub} = [ $1, $2 ];
9208 "No subroutines in $_, ignoring breakpoints.\n";
9211 LINES: for $line ( keys %dbline ) {
9213 # One breakpoint per sub only:
9214 my ( $offset, $sub, $found );
9215 SUBS: for $sub ( keys %subs ) {
9218 $line # Not after the subroutine
9220 not defined $offset # Not caught
9226 $offset = $line - $subs{$sub}->[0];
9227 $offset = "+$offset", last SUBS
9229 } ## end if ($subs{$sub}->[1] >=...
9230 } ## end for $sub (keys %subs)
9231 if ( defined $offset ) {
9232 $postponed{$found} =
9233 "break $offset if $dbline{$line}";
9237 "Breakpoint in $_:$line ignored: after all the subroutines.\n";
9239 } ## end for $line (keys %dbline)
9240 } ## end for (@hard)
9242 # Save the other things that don't need to be
9244 set_list( "PERLDB_POSTPONE", %postponed );
9245 set_list( "PERLDB_PRETYPE", @$pretype );
9246 set_list( "PERLDB_PRE", @$pre );
9247 set_list( "PERLDB_POST", @$post );
9248 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9250 # We are officially restarting.
9251 $ENV{PERLDB_RESTART} = 1;
9253 # We are junking all child debuggers.
9254 delete $ENV{PERLDB_PIDS}; # Restore ini state
9256 # Set this back to the initial pid.
9257 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9261 After all the debugger status has been saved, we take the command we built up
9262 and then return it, so we can C<exec()> it. The debugger will spot the
9263 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9264 from the environment.
9268 # And run Perl again. Add the "-d" flag, all the
9269 # flags we built up, the script (whether a one-liner
9270 # or a file), add on the -emacs flag for a slave editor,
9271 # and then the old arguments.
9273 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9279 =head1 END PROCESSING - THE C<END> BLOCK
9281 Come here at the very end of processing. We want to go into a
9282 loop where we allow the user to enter commands and interact with the
9283 debugger, but we don't want anything else to execute.
9285 First we set the C<$finished> variable, so that some commands that
9286 shouldn't be run after the end of program quit working.
9288 We then figure out whether we're truly done (as in the user entered a C<q>
9289 command, or we finished execution while running nonstop). If we aren't,
9290 we set C<$single> to 1 (causing the debugger to get control again).
9292 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9293 message and returns control to the debugger. Repeat.
9295 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9296 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9297 break, run to completion.).
9302 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9303 $fall_off_end = 1 unless $inhibit_exit;
9305 # Do not stop in at_exit() and destructors on exit:
9306 if ($fall_off_end or $runnonstop) {
9310 DB::fake::at_exit();
9314 =head1 PRE-5.8 COMMANDS
9316 Some of the commands changed function quite a bit in the 5.8 command
9317 realignment, so much so that the old code had to be replaced completely.
9318 Because we wanted to retain the option of being able to go back to the
9319 former command set, we moved the old code off to this section.
9321 There's an awful lot of duplicated code here. We've duplicated the
9322 comments to keep things clear.
9326 Does nothing. Used to I<turn off> commands.
9330 sub cmd_pre580_null {
9335 =head2 Old C<a> command.
9337 This version added actions if you supplied them, and deleted them
9346 # Argument supplied. Add the action.
9347 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9349 # If the line isn't there, use the current line.
9353 # If there is an action ...
9356 # ... but the line isn't breakable, skip it.
9357 if ( $dbline[$i] == 0 ) {
9358 print $OUT "Line $i may not have an action.\n";
9362 # ... and the line is breakable:
9363 # Mark that there's an action in this file.
9364 $had_breakpoints{$filename} |= 2;
9366 # Delete any current action.
9367 $dbline{$i} =~ s/\0[^\0]*//;
9369 # Add the new action, continuing the line as needed.
9370 $dbline{$i} .= "\0" . action($j);
9372 } ## end if (length $j)
9374 # No action supplied.
9377 # Delete the action.
9378 $dbline{$i} =~ s/\0[^\0]*//;
9380 # Mark as having no break or action if nothing's left.
9381 delete $dbline{$i} if $dbline{$i} eq '';
9383 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
9384 } ## end sub cmd_pre580_a
9386 =head2 Old C<b> command
9398 if ( $cmd =~ /^load\b\s*(.*)/ ) {
9404 # b compile|postpone <some sub> [<condition>]
9405 # The interpreter actually traps this one for us; we just put the
9406 # necessary condition in the %postponed hash.
9407 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
9409 # Capture the condition if there is one. Make it true if none.
9410 my $cond = length $3 ? $3 : '1';
9412 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
9413 # if it was 'compile'.
9414 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
9416 # De-Perl4-ify the name - ' separators to ::.
9417 $subname =~ s/\'/::/g;
9419 # Qualify it into the current package unless it's already qualified.
9420 $subname = "${'package'}::" . $subname
9421 unless $subname =~ /::/;
9423 # Add main if it starts with ::.
9424 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
9426 # Save the break type for this sub.
9427 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
9428 } ## end elsif ($cmd =~ ...
9430 # b <sub name> [<condition>]
9431 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
9433 my $cond = length $2 ? $2 : '1';
9434 &cmd_b_sub( $subname, $cond );
9436 # b <line> [<condition>].
9437 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9438 my $i = $1 || $dbline;
9439 my $cond = length $2 ? $2 : '1';
9440 &cmd_b_line( $i, $cond );
9442 } ## end sub cmd_pre580_b
9444 =head2 Old C<D> command.
9446 Delete all breakpoints unconditionally.
9453 if ( $cmd =~ /^\s*$/ ) {
9454 print $OUT "Deleting all breakpoints...\n";
9456 # %had_breakpoints lists every file that had at least one
9459 for $file ( keys %had_breakpoints ) {
9461 # Switch to the desired file temporarily.
9462 local *dbline = $main::{ '_<' . $file };
9467 # For all lines in this file ...
9468 for ( $i = 1 ; $i <= $max ; $i++ ) {
9470 # If there's a breakpoint or action on this line ...
9471 if ( defined $dbline{$i} ) {
9473 # ... remove the breakpoint.
9474 $dbline{$i} =~ s/^[^\0]+//;
9475 if ( $dbline{$i} =~ s/^\0?$// ) {
9477 # Remove the entry altogether if no action is there.
9480 } ## end if (defined $dbline{$i...
9481 } ## end for ($i = 1 ; $i <= $max...
9483 # If, after we turn off the "there were breakpoints in this file"
9484 # bit, the entry in %had_breakpoints for this file is zero,
9485 # we should remove this file from the hash.
9486 if ( not $had_breakpoints{$file} &= ~1 ) {
9487 delete $had_breakpoints{$file};
9489 } ## end for $file (keys %had_breakpoints)
9491 # Kill off all the other breakpoints that are waiting for files that
9492 # haven't been loaded yet.
9494 undef %postponed_file;
9495 undef %break_on_load;
9496 } ## end if ($cmd =~ /^\s*$/)
9497 } ## end sub cmd_pre580_D
9499 =head2 Old C<h> command
9501 Print help. Defaults to printing the long-form help; the 5.8 version
9502 prints the summary by default.
9510 # Print the *right* help, long format.
9511 if ( $cmd =~ /^\s*$/ ) {
9512 print_help($pre580_help);
9515 # 'h h' - explicitly-requested summary.
9516 elsif ( $cmd =~ /^h\s*/ ) {
9517 print_help($pre580_summary);
9520 # Find and print a command's help.
9521 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
9522 my $asked = $1; # for proper errmsg
9523 my $qasked = quotemeta($asked); # for searching
9524 # XXX: finds CR but not <CR>
9528 (?:[IB]<) # Optional markup
9529 $qasked # The command name
9536 ( # The command help:
9538 (?:[IB]<) # Optional markup
9539 $qasked # The command name
9540 ([\s\S]*?) # Lines starting with tabs
9544 ) # Line not starting with space
9545 # (Next command's help)
9549 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
9553 print_help("B<$asked> is not a debugger command.\n");
9555 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
9556 } ## end sub cmd_pre580_h
9558 =head2 Old C<W> command
9560 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
9568 # Delete all watch expressions.
9569 if ( $cmd =~ /^$/ ) {
9571 # No watching is going on.
9574 # Kill all the watch expressions and values.
9575 @to_watch = @old_watch = ();
9578 # Add a watch expression.
9579 elsif ( $cmd =~ /^(.*)/s ) {
9581 # add it to the list to be watched.
9584 # Get the current value of the expression.
9585 # Doesn't handle expressions returning list values!
9588 $val = ( defined $val ) ? "'$val'" : 'undef';
9591 push @old_watch, $val;
9593 # We're watching stuff.
9596 } ## end elsif ($cmd =~ /^(.*)/s)
9597 } ## end sub cmd_pre580_W
9599 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
9601 The debugger used to have a bunch of nearly-identical code to handle
9602 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
9603 C<cmd_prepost> unify all this into one set of code to handle the
9604 appropriate actions.
9606 =head2 C<cmd_pre590_prepost>
9608 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
9609 do something destructive. In pre 5.8 debuggers, the default action was to
9610 delete all the actions.
9614 sub cmd_pre590_prepost {
9616 my $line = shift || '*';
9619 return &cmd_prepost( $cmd, $line, $dbline );
9620 } ## end sub cmd_pre590_prepost
9622 =head2 C<cmd_prepost>
9624 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
9625 Since the lists of actions are all held in arrays that are pointed to by
9626 references anyway, all we have to do is pick the right array reference and
9627 then use generic code to all, delete, or list actions.
9634 # No action supplied defaults to 'list'.
9635 my $line = shift || '?';
9637 # Figure out what to put in the prompt.
9640 # Make sure we have some array or another to address later.
9641 # This means that if ssome reason the tests fail, we won't be
9642 # trying to stash actions or delete them from the wrong place.
9645 # < - Perl code to run before prompt.
9646 if ( $cmd =~ /^\</o ) {
9647 $which = 'pre-perl';
9651 # > - Perl code to run after prompt.
9652 elsif ( $cmd =~ /^\>/o ) {
9653 $which = 'post-perl';
9657 # { - first check for properly-balanced braces.
9658 elsif ( $cmd =~ /^\{/o ) {
9659 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
9661 "$cmd is now a debugger command\nuse ';$cmd' if you mean Perl code\n";
9664 # Properly balanced. Pre-prompt debugger actions.
9666 $which = 'pre-debugger';
9669 } ## end elsif ( $cmd =~ /^\{/o )
9671 # Did we find something that makes sense?
9673 print $OUT "Confused by command: $cmd\n";
9680 if ( $line =~ /^\s*\?\s*$/o ) {
9683 # Nothing there. Complain.
9684 print $OUT "No $which actions.\n";
9688 # List the actions in the selected list.
9689 print $OUT "$which commands:\n";
9690 foreach my $action (@$aref) {
9691 print $OUT "\t$cmd -- $action\n";
9694 } ## end if ( $line =~ /^\s*\?\s*$/o)
9696 # Might be a delete.
9698 if ( length($cmd) == 1 ) {
9699 if ( $line =~ /^\s*\*\s*$/o ) {
9701 # It's a delete. Get rid of the old actions in the
9704 print $OUT "All $cmd actions cleared.\n";
9708 # Replace all the actions. (This is a <, >, or {).
9709 @$aref = action($line);
9711 } ## end if ( length($cmd) == 1)
9712 elsif ( length($cmd) == 2 ) {
9714 # Add the action to the line. (This is a <<, >>, or {{).
9715 push @$aref, action($line);
9719 # <<<, >>>>, {{{{{{ ... something not a command.
9721 "Confused by strange length of $which command($cmd)...\n";
9723 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
9725 } ## end sub cmd_prepost
9729 Contains the C<at_exit> routine that the debugger uses to issue the
9730 C<Debugged program terminated ...> message after the program completes. See
9731 the C<END> block documentation for more details.
9738 "Debugged program terminated. Use 'q' to quit or 'R' to restart.";
9741 package DB; # Do not trace this 1; below!