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> via glob
177 assignment) contains the text from C<$filename>, with each element
178 corresponding to a single line of C<$filename>.
180 The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
181 assignment) contains breakpoints and actions. The keys are line numbers;
182 you can set individual values, but not the whole hash. The Perl interpreter
183 uses this hash to determine where breakpoints have been set. Any true value is
184 considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>.
185 Values are magical in numeric context: 1 if the line is breakable, 0 if not.
187 The scalar C<${"_<$filename"}> simply contains the string C<_<$filename>.
188 This is also the case for evaluated strings that contain subroutines, or
189 which are currently being executed. The $filename for C<eval>ed strings looks
190 like C<(eval 34)> or C<(re_eval 19)>.
192 =head1 DEBUGGER STARTUP
194 When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
195 non-interactive sessions, C<.perldb> for interactive ones) that can set a number
196 of options. In addition, this file may define a subroutine C<&afterinit>
197 that will be executed (in the debugger's context) after the debugger has
200 Next, it checks the C<PERLDB_OPTS> environment variable and treats its
201 contents as the argument of a C<o> command in the debugger.
203 =head2 STARTUP-ONLY OPTIONS
205 The following options can only be specified at startup.
206 To set them in your rcfile, add a call to
207 C<&parse_options("optionName=new_value")>.
213 the TTY to use for debugging i/o.
217 if set, goes in NonStop mode. On interrupt, if TTY is not set,
218 uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using
219 Term::Rendezvous. Current variant is to have the name of TTY in this
224 if false, a dummy ReadLine is used, so you can debug
225 ReadLine applications.
229 if true, no i/o is performed until interrupt.
233 file or pipe to print line number info to. If it is a
234 pipe, a short "emacs like" message is used.
238 host:port to connect to on remote host for remote debugging.
242 file to store session history to. There is no default and so no
243 history file is written unless this variable is explicitly set.
247 number of commands to store to the file specified in C<HistFile>.
254 &parse_options("NonStop=1 LineInfo=db.out");
255 sub afterinit { $trace = 1; }
257 The script will run without human intervention, putting trace
258 information into C<db.out>. (If you interrupt it, you had better
259 reset C<LineInfo> to something I<interactive>!)
261 =head1 INTERNALS DESCRIPTION
263 =head2 DEBUGGER INTERFACE VARIABLES
265 Perl supplies the values for C<%sub>. It effectively inserts
266 a C<&DB::DB();> in front of each place that can have a
267 breakpoint. At each subroutine call, it calls C<&DB::sub> with
268 C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
269 {require 'perl5db.pl'}> before the first line.
271 After each C<require>d file is compiled, but before it is executed, a
272 call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
273 is the expanded name of the C<require>d file (as found via C<%INC>).
275 =head3 IMPORTANT INTERNAL VARIABLES
279 Used to control when the debugger will attempt to acquire another TTY to be
284 =item * 1 - on C<fork()>
286 =item * 2 - debugger is started inside debugger
288 =item * 4 - on startup
294 The value -2 indicates that no return value should be printed.
295 Any other positive value causes C<DB::sub> to print return values.
299 The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
300 contents of C<@_> when C<DB::eval> is called.
304 Determines what messages (if any) will get printed when a subroutine (or eval)
305 is entered or exited.
309 =item * 0 - No enter/exit messages
311 =item * 1 - Print I<entering> messages on subroutine entry
313 =item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
315 =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.
317 =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.
319 =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.
323 To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
324 The debugger internally juggles the value of C<$frame> during execution to
325 protect external modules that the debugger uses from getting traced.
329 Tracks current debugger nesting level. Used to figure out how many
330 C<E<lt>E<gt>> pairs to surround the line number with when the debugger
331 outputs a prompt. Also used to help determine if the program has finished
332 during command parsing.
334 =head4 C<$onetimeDump>
336 Controls what (if anything) C<DB::eval()> will print after evaluating an
341 =item * C<undef> - don't print anything
343 =item * C<dump> - use C<dumpvar.pl> to display the value returned
345 =item * C<methods> - print the methods callable on the first item returned
349 =head4 C<$onetimeDumpDepth>
351 Controls how far down C<dumpvar.pl> will go before printing C<...> while
352 dumping a structure. Numeric. If C<undef>, print all levels.
356 Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
357 which is called before every statement, checks this and puts the user into
358 command mode if it finds C<$signal> set to a true value.
362 Controls behavior during single-stepping. Stacked in C<@stack> on entry to
363 each subroutine; popped again at the end of each subroutine.
367 =item * 0 - run continuously.
369 =item * 1 - single-step, go into subs. The C<s> command.
371 =item * 2 - single-step, don't go into subs. The C<n> command.
373 =item * 4 - print current sub depth (turned on to force this when C<too much
380 Controls the output of trace information.
384 =item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
386 =item * 2 - watch expressions are active
388 =item * 4 - user defined a C<watchfunction()> in C<afterinit()>
392 =head4 C<$slave_editor>
394 1 if C<LINEINFO> was directed to a pipe; 0 otherwise.
398 Stack of filehandles that C<DB::readline()> will read commands from.
399 Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
403 Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
404 supplied by the Perl interpreter to the debugger. Contains the source.
408 Previous values of watch expressions. First set when the expression is
409 entered; reset whenever the watch expression changes.
413 Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
414 so that the debugger can substitute safe values while it's running, and
415 restore them when it returns control.
419 Saves the current value of C<$single> on entry to a subroutine.
420 Manipulated by the C<c> command to turn off tracing in all subs above the
425 The 'watch' expressions: to be evaluated before each line is executed.
429 The typeahead buffer, used by C<DB::readline>.
433 Command aliases. Stored as character strings to be substituted for a command
436 =head4 C<%break_on_load>
438 Keys are file names, values are 1 (break when this file is loaded) or undef
439 (don't break when it is loaded).
443 Keys are line numbers, values are C<condition\0action>. If used in numeric
444 context, values are 0 if not breakable, 1 if breakable, no matter what is
445 in the actual hash entry.
447 =head4 C<%had_breakpoints>
449 Keys are file names; values are bitfields:
453 =item * 1 - file has a breakpoint in it.
455 =item * 2 - file has an action in it.
459 A zero or undefined value means this file has neither.
463 Stores the debugger options. These are character string values.
467 Saves breakpoints for code that hasn't been compiled yet.
468 Keys are subroutine names, values are:
472 =item * C<compile> - break when this sub is compiled
474 =item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
478 =head4 C<%postponed_file>
480 This hash keeps track of breakpoints that need to be set for files that have
481 not yet been compiled. Keys are filenames; values are references to hashes.
482 Each of these hashes is keyed by line number, and its values are breakpoint
483 definitions (C<condition\0action>).
485 =head1 DEBUGGER INITIALIZATION
487 The debugger's initialization actually jumps all over the place inside this
488 package. This is because there are several BEGIN blocks (which of course
489 execute immediately) spread through the code. Why is that?
491 The debugger needs to be able to change some things and set some things up
492 before the debugger code is compiled; most notably, the C<$deep> variable that
493 C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
494 debugger has to turn off warnings while the debugger code is compiled, but then
495 restore them to their original setting before the program being debugged begins
498 The first C<BEGIN> block simply turns off warnings by saving the current
499 setting of C<$^W> and then setting it to zero. The second one initializes
500 the debugger variables that are needed before the debugger begins executing.
501 The third one puts C<$^X> back to its former value.
503 We'll detail the second C<BEGIN> block later; just remember that if you need
504 to initialize something before the debugger starts really executing, that's
511 BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
513 # Debugger for Perl 5.00x; perl5db.pl patch level:
516 $header = "perl5db.pl version $VERSION";
518 =head1 DEBUGGER ROUTINES
522 This function replaces straight C<eval()> inside the debugger; it simplifies
523 the process of evaluating code in the user's context.
525 The code to be evaluated is passed via the package global variable
526 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
528 Before we do the C<eval()>, we preserve the current settings of C<$trace>,
529 C<$single>, C<$^D> and C<$usercontext>. The latter contains the
530 preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
531 user's current package, grabbed when C<DB::DB> got control. This causes the
532 proper context to be used when the eval is actually done. Afterward, we
533 restore C<$trace>, C<$single>, and C<$^D>.
535 Next we need to handle C<$@> without getting confused. We save C<$@> in a
536 local lexical, localize C<$saved[0]> (which is where C<save()> will put
537 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
538 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
539 considered sane by the debugger. If there was an C<eval()> error, we print
540 it on the debugger's output. If C<$onetimedump> is defined, we call
541 C<dumpit> if it's set to 'dump', or C<methods> if it's set to
542 'methods'. Setting it to something else causes the debugger to do the eval
543 but not print the result - handy if you want to do something else with it
544 (the "watch expressions" code does this to get the value of the watch
545 expression but not show it unless it matters).
547 In any case, we then return the list of output from C<eval> to the caller,
548 and unwinding restores the former version of C<$@> in C<@saved> as well
549 (the localization of C<$saved[0]> goes away at the end of this scope).
551 =head3 Parameters and variables influencing execution of DB::eval()
553 C<DB::eval> isn't parameterized in the standard way; this is to keep the
554 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
555 The variables listed below influence C<DB::eval()>'s execution directly.
559 =item C<$evalarg> - the thing to actually be eval'ed
561 =item C<$trace> - Current state of execution tracing
563 =item C<$single> - Current state of single-stepping
565 =item C<$onetimeDump> - what is to be displayed after the evaluation
567 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
571 The following variables are altered by C<DB::eval()> during its execution. They
572 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
576 =item C<@res> - used to capture output from actual C<eval>.
578 =item C<$otrace> - saved value of C<$trace>.
580 =item C<$osingle> - saved value of C<$single>.
582 =item C<$od> - saved value of C<$^D>.
584 =item C<$saved[0]> - saved value of C<$@>.
586 =item $\ - for output of C<$@> if there is an evaluation error.
590 =head3 The problem of lexicals
592 The context of C<DB::eval()> presents us with some problems. Obviously,
593 we want to be 'sandboxed' away from the debugger's internals when we do
594 the eval, but we need some way to control how punctuation variables and
595 debugger globals are used.
597 We can't use local, because the code inside C<DB::eval> can see localized
598 variables; and we can't use C<my> either for the same reason. The code
599 in this routine compromises and uses C<my>.
601 After this routine is over, we don't have user code executing in the debugger's
602 context, so we can use C<my> freely.
606 ############################################## Begin lexical danger zone
608 # 'my' variables used here could leak into (that is, be visible in)
609 # the context that the code being evaluated is executing in. This means that
610 # the code could modify the debugger's variables.
612 # Fiddling with the debugger's context could be Bad. We insulate things as
617 # 'my' would make it visible from user code
618 # but so does local! --tchrist
619 # Remember: this localizes @DB::res, not @main::res.
623 # Try to keep the user code from messing with us. Save these so that
624 # even if the eval'ed code changes them, we can put them back again.
625 # Needed because the user could refer directly to the debugger's
626 # package globals (and any 'my' variables in this containing scope)
627 # inside the eval(), and we want to try to stay safe.
628 local $otrace = $trace;
629 local $osingle = $single;
632 # Untaint the incoming eval() argument.
633 { ($evalarg) = $evalarg =~ /(.*)/s; }
635 # $usercontext built in DB::DB near the comment
636 # "set up the context for DB::eval ..."
637 # Evaluate and save any results.
638 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
640 # Restore those old values.
646 # Save the current value of $@, and preserve it in the debugger's copy
647 # of the saved precious globals.
650 # Since we're only saving $@, we only have to localize the array element
651 # that it will be stored in.
652 local $saved[0]; # Preserve the old value of $@
655 # Now see whether we need to report an error back to the user.
661 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
662 # are package globals.
663 elsif ($onetimeDump) {
664 if ( $onetimeDump eq 'dump' ) {
665 local $option{dumpDepth} = $onetimedumpDepth
666 if defined $onetimedumpDepth;
667 dumpit( $OUT, \@res );
669 elsif ( $onetimeDump eq 'methods' ) {
672 } ## end elsif ($onetimeDump)
676 ############################################## End lexical danger zone
678 # After this point it is safe to introduce lexicals.
679 # The code being debugged will be executing in its own context, and
680 # can't see the inside of the debugger.
682 # However, one should not overdo it: leave as much control from outside as
683 # possible. If you make something a lexical, it's not going to be addressable
684 # from outside the debugger even if you know its name.
686 # This file is automatically included if you do perl -d.
687 # It's probably not useful to include this yourself.
689 # Before venturing further into these twisty passages, it is
690 # wise to read the perldebguts man page or risk the ire of dragons.
692 # (It should be noted that perldebguts will tell you a lot about
693 # the underlying mechanics of how the debugger interfaces into the
694 # Perl interpreter, but not a lot about the debugger itself. The new
695 # comments in this code try to address this problem.)
697 # Note that no subroutine call is possible until &DB::sub is defined
698 # (for subroutines defined outside of the package DB). In fact the same is
699 # true if $deep is not defined.
701 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
703 # modified Perl debugger, to be run from Emacs in perldb-mode
704 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
705 # Johan Vromans -- upgrade to 4.0 pl 10
706 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
708 # (We have made efforts to clarify the comments in the change log
709 # in other places; some of them may seem somewhat obscure as they
710 # were originally written, and explaining them away from the code
711 # in question seems conterproductive.. -JM)
713 ########################################################################
715 # + A lot of things changed after 0.94. First of all, core now informs
716 # debugger about entry into XSUBs, overloaded operators, tied operations,
717 # BEGIN and END. Handy with `O f=2'.
718 # + This can make debugger a little bit too verbose, please be patient
719 # and report your problems promptly.
720 # + Now the option frame has 3 values: 0,1,2. XXX Document!
721 # + Note that if DESTROY returns a reference to the object (or object),
722 # the deletion of data may be postponed until the next function call,
723 # due to the need to examine the return value.
726 # + `v' command shows versions.
729 # + `v' command shows version of readline.
730 # primitive completion works (dynamic variables, subs for `b' and `l',
731 # options). Can `p %var'
732 # + Better help (`h <' now works). New commands <<, >>, {, {{.
733 # {dump|print}_trace() coded (to be able to do it from <<cmd).
734 # + `c sub' documented.
735 # + At last enough magic combined to stop after the end of debuggee.
736 # + !! should work now (thanks to Emacs bracket matching an extra
737 # `]' in a regexp is caught).
738 # + `L', `D' and `A' span files now (as documented).
739 # + Breakpoints in `require'd code are possible (used in `R').
740 # + Some additional words on internal work of debugger.
741 # + `b load filename' implemented.
742 # + `b postpone subr' implemented.
743 # + now only `q' exits debugger (overwritable on $inhibit_exit).
744 # + When restarting debugger breakpoints/actions persist.
745 # + Buglet: When restarting debugger only one breakpoint/action per
746 # autoloaded function persists.
748 # Changes: 0.97: NonStop will not stop in at_exit().
749 # + Option AutoTrace implemented.
750 # + Trace printed differently if frames are printed too.
751 # + new `inhibitExit' option.
752 # + printing of a very long statement interruptible.
753 # Changes: 0.98: New command `m' for printing possible methods
754 # + 'l -' is a synonym for `-'.
755 # + Cosmetic bugs in printing stack trace.
756 # + `frame' & 8 to print "expanded args" in stack trace.
757 # + Can list/break in imported subs.
758 # + new `maxTraceLen' option.
759 # + frame & 4 and frame & 8 granted.
761 # + nonstoppable lines do not have `:' near the line number.
762 # + `b compile subname' implemented.
763 # + Will not use $` any more.
764 # + `-' behaves sane now.
765 # Changes: 0.99: Completion for `f', `m'.
766 # + `m' will remove duplicate names instead of duplicate functions.
767 # + `b load' strips trailing whitespace.
768 # completion ignores leading `|'; takes into account current package
769 # when completing a subroutine name (same for `l').
770 # Changes: 1.07: Many fixed by tchrist 13-March-2000
772 # + Added bare minimal security checks on perldb rc files, plus
773 # comments on what else is needed.
774 # + Fixed the ornaments that made "|h" completely unusable.
775 # They are not used in print_help if they will hurt. Strip pod
776 # if we're paging to less.
777 # + Fixed mis-formatting of help messages caused by ornaments
778 # to restore Larry's original formatting.
779 # + Fixed many other formatting errors. The code is still suboptimal,
780 # and needs a lot of work at restructuring. It's also misindented
782 # + Fixed bug where trying to look at an option like your pager
784 # + Fixed some $? processing. Note: if you use csh or tcsh, you will
785 # lose. You should consider shell escapes not using their shell,
786 # or else not caring about detailed status. This should really be
787 # unified into one place, too.
788 # + Fixed bug where invisible trailing whitespace on commands hoses you,
789 # tricking Perl into thinking you weren't calling a debugger command!
790 # + Fixed bug where leading whitespace on commands hoses you. (One
791 # suggests a leading semicolon or any other irrelevant non-whitespace
792 # to indicate literal Perl code.)
793 # + Fixed bugs that ate warnings due to wrong selected handle.
794 # + Fixed a precedence bug on signal stuff.
795 # + Fixed some unseemly wording.
796 # + Fixed bug in help command trying to call perl method code.
797 # + Fixed to call dumpvar from exception handler. SIGPIPE killed us.
799 # + Added some comments. This code is still nasty spaghetti.
800 # + Added message if you clear your pre/post command stacks which was
801 # very easy to do if you just typed a bare >, <, or {. (A command
802 # without an argument should *never* be a destructive action; this
803 # API is fundamentally screwed up; likewise option setting, which
804 # is equally buggered.)
805 # + Added command stack dump on argument of "?" for >, <, or {.
806 # + Added a semi-built-in doc viewer command that calls man with the
807 # proper %Config::Config path (and thus gets caching, man -k, etc),
808 # or else perldoc on obstreperous platforms.
809 # + Added to and rearranged the help information.
810 # + Detected apparent misuse of { ... } to declare a block; this used
811 # to work but now is a command, and mysteriously gave no complaint.
813 # Changes: 1.08: Apr 25, 2001 Jon Eveland <jweveland@yahoo.com>
815 # + This patch to perl5db.pl cleans up formatting issues on the help
816 # summary (h h) screen in the debugger. Mostly columnar alignment
817 # issues, plus converted the printed text to use all spaces, since
818 # tabs don't seem to help much here.
820 # Changes: 1.09: May 19, 2001 Ilya Zakharevich <ilya@math.ohio-state.edu>
821 # Minor bugs corrected;
822 # + Support for auto-creation of new TTY window on startup, either
823 # unconditionally, or if started as a kid of another debugger session;
824 # + New `O'ption CreateTTY
825 # I<CreateTTY> bits control attempts to create a new TTY on events:
827 # 2: debugger is started inside debugger
829 # + Code to auto-create a new TTY window on OS/2 (currently one
830 # extra window per session - need named pipes to have more...);
831 # + Simplified interface for custom createTTY functions (with a backward
832 # compatibility hack); now returns the TTY name to use; return of ''
833 # means that the function reset the I/O handles itself;
834 # + Better message on the semantic of custom createTTY function;
835 # + Convert the existing code to create a TTY into a custom createTTY
837 # + Consistent support for TTY names of the form "TTYin,TTYout";
838 # + Switch line-tracing output too to the created TTY window;
839 # + make `b fork' DWIM with CORE::GLOBAL::fork;
840 # + High-level debugger API cmd_*():
841 # cmd_b_load($filenamepart) # b load filenamepart
842 # cmd_b_line($lineno [, $cond]) # b lineno [cond]
843 # cmd_b_sub($sub [, $cond]) # b sub [cond]
844 # cmd_stop() # Control-C
845 # cmd_d($lineno) # d lineno (B)
846 # The cmd_*() API returns FALSE on failure; in this case it outputs
847 # the error message to the debugging output.
848 # + Low-level debugger API
849 # break_on_load($filename) # b load filename
850 # @files = report_break_on_load() # List files with load-breakpoints
851 # breakable_line_in_filename($name, $from [, $to])
852 # # First breakable line in the
853 # # range $from .. $to. $to defaults
854 # # to $from, and may be less than
856 # breakable_line($from [, $to]) # Same for the current file
857 # break_on_filename_line($name, $lineno [, $cond])
858 # # Set breakpoint,$cond defaults to
860 # break_on_filename_line_range($name, $from, $to [, $cond])
861 # # As above, on the first
862 # # breakable line in range
863 # break_on_line($lineno [, $cond]) # As above, in the current file
864 # break_subroutine($sub [, $cond]) # break on the first breakable line
865 # ($name, $from, $to) = subroutine_filename_lines($sub)
866 # # The range of lines of the text
867 # The low-level API returns TRUE on success, and die()s on failure.
869 # Changes: 1.10: May 23, 2001 Daniel Lewart <d-lewart@uiuc.edu>
871 # + Fixed warnings generated by "perl -dWe 42"
872 # + Corrected spelling errors
873 # + Squeezed Help (h) output into 80 columns
875 # Changes: 1.11: May 24, 2001 David Dyck <dcd@tc.fluke.com>
876 # + Made "x @INC" work like it used to
878 # Changes: 1.12: May 24, 2001 Daniel Lewart <d-lewart@uiuc.edu>
879 # + Fixed warnings generated by "O" (Show debugger options)
880 # + Fixed warnings generated by "p 42" (Print expression)
881 # Changes: 1.13: Jun 19, 2001 Scott.L.Miller@compaq.com
882 # + Added windowSize option
883 # Changes: 1.14: Oct 9, 2001 multiple
884 # + Clean up after itself on VMS (Charles Lane in 12385)
885 # + Adding "@ file" syntax (Peter Scott in 12014)
886 # + Debug reloading selfloaded stuff (Ilya Zakharevich in 11457)
887 # + $^S and other debugger fixes (Ilya Zakharevich in 11120)
888 # + Forgot a my() declaration (Ilya Zakharevich in 11085)
889 # Changes: 1.15: Nov 6, 2001 Michael G Schwern <schwern@pobox.com>
890 # + Updated 1.14 change log
891 # + Added *dbline explainatory comments
892 # + Mentioning perldebguts man page
893 # Changes: 1.16: Feb 15, 2002 Mark-Jason Dominus <mjd@plover.com>
894 # + $onetimeDump improvements
895 # Changes: 1.17: Feb 20, 2002 Richard Foley <richard.foley@rfi.net>
896 # Moved some code to cmd_[.]()'s for clarity and ease of handling,
897 # rationalised the following commands and added cmd_wrapper() to
898 # enable switching between old and frighteningly consistent new
899 # behaviours for diehards: 'o CommandSet=pre580' (sigh...)
900 # a(add), A(del) # action expr (added del by line)
901 # + b(add), B(del) # break [line] (was b,D)
902 # + w(add), W(del) # watch expr (was W,W)
903 # # added del by expr
904 # + h(summary), h h(long) # help (hh) (was h h,h)
905 # + m(methods), M(modules) # ... (was m,v)
906 # + o(option) # lc (was O)
907 # + v(view code), V(view Variables) # ... (was w,V)
908 # Changes: 1.18: Mar 17, 2002 Richard Foley <richard.foley@rfi.net>
909 # + fixed missing cmd_O bug
910 # Changes: 1.19: Mar 29, 2002 Spider Boardman
911 # + Added missing local()s -- DB::DB is called recursively.
912 # Changes: 1.20: Feb 17, 2003 Richard Foley <richard.foley@rfi.net>
913 # + pre'n'post commands no longer trashed with no args
914 # + watch val joined out of eval()
915 # Changes: 1.21: Jun 04, 2003 Joe McMahon <mcmahon@ibiblio.org>
916 # + Added comments and reformatted source. No bug fixes/enhancements.
917 # + Includes cleanup by Robin Barker and Jarkko Hietaniemi.
918 # Changes: 1.22 Jun 09, 2003 Alex Vandiver <alexmv@MIT.EDU>
919 # + Flush stdout/stderr before the debugger prompt is printed.
920 # Changes: 1.23: Dec 21, 2003 Dominique Quatravaux
921 # + Fix a side-effect of bug #24674 in the perl debugger ("odd taint bug")
922 # Changes: 1.24: Mar 03, 2004 Richard Foley <richard.foley@rfi.net>
923 # + Added command to save all debugger commands for sourcing later.
924 # + Added command to display parent inheritance tree of given class.
925 # + Fixed minor newline in history bug.
926 # Changes: 1.25: Apr 17, 2004 Richard Foley <richard.foley@rfi.net>
927 # + Fixed option bug (setting invalid options + not recognising valid short forms)
928 # Changes: 1.26: Apr 22, 2004 Richard Foley <richard.foley@rfi.net>
929 # + unfork the 5.8.x and 5.9.x debuggers.
930 # + whitespace and assertions call cleanup across versions
931 # + H * deletes (resets) history
932 # + i now handles Class + blessed objects
933 # Changes: 1.27: May 09, 2004 Richard Foley <richard.foley@rfi.net>
934 # + updated pod page references - clunky.
935 # + removed windowid restriction for forking into an xterm.
936 # + more whitespace again.
937 # + wrapped restart and enabled rerun [-n] (go back n steps) command.
938 # Changes: 1.28: Oct 12, 2004 Richard Foley <richard.foley@rfi.net>
939 # + Added threads support (inc. e and E commands)
940 # Changes: 1.29: Nov 28, 2006 Bo Lindbergh <blgl@hagernas.com>
941 # + Added macosx_get_fork_TTY support
942 # Changes: 1.30: Mar 06, 2007 Andreas Koenig <andk@cpan.org>
943 # + Added HistFile, HistSize
945 # + Remove support for assertions and -A
946 # + stop NEXT::AUTOLOAD from emitting warnings under the debugger. RT #25053
947 # + "update for Mac OS X 10.5" [finding the tty device]
948 # + "What I needed to get the forked debugger to work" [on VMS]
949 # + [perl #57016] debugger: o warn=0 die=0 ignored
950 # + Note, but don't use, PERLDBf_SAVESRC
951 # + Fix #7013: lvalue subs not working inside debugger
952 # Changes: 1.32: Jun 03, 2009 Jonathan Leto <jonathan@leto.net>
953 # + Fix bug where a key _< with undefined value was put into the symbol table
954 # + when the $filename variable is not set
955 ########################################################################
957 =head1 DEBUGGER INITIALIZATION
959 The debugger starts up in phases.
963 First, it initializes the environment it wants to run in: turning off
964 warnings during its own compilation, defining variables which it will need
965 to avoid warnings later, setting itself up to not exit when the program
966 terminates, and defaulting to printing return values for the C<r> command.
970 # Needed for the statement after exec():
972 # This BEGIN block is simply used to switch off warnings during debugger
973 # compiliation. Probably it would be better practice to fix the warnings,
974 # but this is how it's done at the moment.
979 } # Switch compilation warnings off until another BEGIN.
981 local ($^W) = 0; # Switch run-time warnings off during init.
983 =head2 THREADS SUPPORT
985 If we are running under a threaded Perl, we require threads and threads::shared
986 if the environment variable C<PERL5DB_THREADED> is set, to enable proper
987 threaded debugger control. C<-dt> can also be used to set this.
989 Each new thread will be announced and the debugger prompt will always inform
990 you of each new thread created. It will also indicate the thread id in which
991 we are currently running within the prompt like this:
995 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
996 command prompt. The prompt will show: C<[0]> when running under threads, but
997 not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
999 While running under threads, when you set or delete a breakpoint (etc.), this
1000 will apply to all threads, not just the currently running one. When you are
1001 in a currently executing thread, you will stay there until it completes. With
1002 the current implementation it is not currently possible to hop from one thread
1005 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
1007 Note that threading support was built into the debugger as of Perl version
1008 C<5.8.6> and debugger version C<1.2.8>.
1013 # ensure we can share our non-threaded variables or no-op
1014 if ($ENV{PERL5DB_THREADED}) {
1016 require threads::shared;
1017 import threads::shared qw(share);
1021 print "Threads support enabled\n";
1028 # This would probably be better done with "use vars", but that wasn't around
1029 # when this code was originally written. (Neither was "use strict".) And on
1030 # the principle of not fiddling with something that was working, this was
1033 # These variables control the execution of 'dumpvar.pl'.
1034 $dumpvar::hashDepth,
1035 $dumpvar::arrayDepth,
1036 $dumpvar::dumpDBFiles,
1037 $dumpvar::dumpPackages,
1038 $dumpvar::quoteHighBit,
1039 $dumpvar::printUndef,
1040 $dumpvar::globPrint,
1041 $dumpvar::usageOnly,
1043 # used to save @ARGV and extract any debugger-related flags.
1046 # used to control die() reporting in diesignal()
1049 # used to prevent multiple entries to diesignal()
1050 # (if for instance diesignal() itself dies)
1053 # used to prevent the debugger from running nonstop
1059 # without threads, $filename is not defined until DB::DB is called
1060 foreach my $k (keys (%INC)) {
1061 &share(\$main::{'_<'.$filename}) if defined $filename;
1064 # Command-line + PERLLIB:
1065 # Save the contents of @INC before they are modified elsewhere.
1068 # This was an attempt to clear out the previous values of various
1069 # trapped errors. Apparently it didn't help. XXX More info needed!
1070 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
1072 # We set these variables to safe values. We don't want to blindly turn
1073 # off warnings, because other packages may still want them.
1074 $trace = $signal = $single = 0; # Uninitialized warning suppression
1075 # (local $^W cannot help - other packages!).
1077 # Default to not exiting when program finishes; print the return
1078 # value when the 'r' command is used to return from a subroutine.
1079 $inhibit_exit = $option{PrintRet} = 1;
1081 =head1 OPTION PROCESSING
1083 The debugger's options are actually spread out over the debugger itself and
1084 C<dumpvar.pl>; some of these are variables to be set, while others are
1085 subs to be called with a value. To try to make this a little easier to
1086 manage, the debugger uses a few data structures to define what options
1087 are legal and how they are to be processed.
1089 First, the C<@options> array defines the I<names> of all the options that
1095 CommandSet HistFile HistSize
1096 hashDepth arrayDepth dumpDepth
1097 DumpDBFiles DumpPackages DumpReused
1098 compactDump veryCompact quote
1099 HighBit undefPrint globPrint
1100 PrintRet UsageOnly frame
1102 ReadLine NonStop LineInfo
1103 maxTraceLen recallCommand ShellBang
1104 pager tkRunning ornaments
1105 signalLevel warnLevel dieLevel
1106 inhibit_exit ImmediateStop bareStringify
1107 CreateTTY RemotePort windowSize
1111 @RememberOnROptions = qw(DollarCaretP);
1115 Second, C<optionVars> lists the variables that each option uses to save its
1121 hashDepth => \$dumpvar::hashDepth,
1122 arrayDepth => \$dumpvar::arrayDepth,
1123 CommandSet => \$CommandSet,
1124 DumpDBFiles => \$dumpvar::dumpDBFiles,
1125 DumpPackages => \$dumpvar::dumpPackages,
1126 DumpReused => \$dumpvar::dumpReused,
1127 HighBit => \$dumpvar::quoteHighBit,
1128 undefPrint => \$dumpvar::printUndef,
1129 globPrint => \$dumpvar::globPrint,
1130 UsageOnly => \$dumpvar::usageOnly,
1131 CreateTTY => \$CreateTTY,
1132 bareStringify => \$dumpvar::bareStringify,
1134 AutoTrace => \$trace,
1135 inhibit_exit => \$inhibit_exit,
1136 maxTraceLen => \$maxtrace,
1137 ImmediateStop => \$ImmediateStop,
1138 RemotePort => \$remoteport,
1139 windowSize => \$window,
1140 HistFile => \$histfile,
1141 HistSize => \$histsize,
1146 Third, C<%optionAction> defines the subroutine to be called to process each
1152 compactDump => \&dumpvar::compactDump,
1153 veryCompact => \&dumpvar::veryCompact,
1154 quote => \&dumpvar::quote,
1157 ReadLine => \&ReadLine,
1158 NonStop => \&NonStop,
1159 LineInfo => \&LineInfo,
1160 recallCommand => \&recallCommand,
1161 ShellBang => \&shellBang,
1163 signalLevel => \&signalLevel,
1164 warnLevel => \&warnLevel,
1165 dieLevel => \&dieLevel,
1166 tkRunning => \&tkRunning,
1167 ornaments => \&ornaments,
1168 RemotePort => \&RemotePort,
1169 DollarCaretP => \&DollarCaretP,
1174 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1179 # Note that this list is not complete: several options not listed here
1180 # actually require that dumpvar.pl be loaded for them to work, but are
1181 # not in the table. A subsequent patch will correct this problem; for
1182 # the moment, we're just recommenting, and we are NOT going to change
1185 compactDump => 'dumpvar.pl',
1186 veryCompact => 'dumpvar.pl',
1187 quote => 'dumpvar.pl',
1192 There are a number of initialization-related variables which can be set
1193 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1194 variable. These are:
1198 =item C<$rl> - readline control XXX needs more explanation
1200 =item C<$warnLevel> - whether or not debugger takes over warning handling
1202 =item C<$dieLevel> - whether or not debugger takes over die handling
1204 =item C<$signalLevel> - whether or not debugger takes over signal handling
1206 =item C<$pre> - preprompt actions (array reference)
1208 =item C<$post> - postprompt actions (array reference)
1212 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1214 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1220 # These guys may be defined in $ENV{PERL5DB} :
1221 $rl = 1 unless defined $rl;
1222 $warnLevel = 1 unless defined $warnLevel;
1223 $dieLevel = 1 unless defined $dieLevel;
1224 $signalLevel = 1 unless defined $signalLevel;
1225 $pre = [] unless defined $pre;
1226 $post = [] unless defined $post;
1227 $pretype = [] unless defined $pretype;
1228 $CreateTTY = 3 unless defined $CreateTTY;
1229 $CommandSet = '580' unless defined $CommandSet;
1234 share($signalLevel);
1244 The default C<die>, C<warn>, and C<signal> handlers are set up.
1248 warnLevel($warnLevel);
1249 dieLevel($dieLevel);
1250 signalLevel($signalLevel);
1254 The pager to be used is needed next. We try to get it from the
1255 environment first. If it's not defined there, we try to find it in
1256 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1257 then call the C<pager()> function to save the pager name.
1261 # This routine makes sure $pager is set up so that '|' can use it.
1264 # If PAGER is defined in the environment, use it.
1268 # If not, see if Config.pm defines it.
1269 : eval { require Config }
1270 && defined $Config::Config{pager}
1271 ? $Config::Config{pager}
1273 # If not, fall back to 'more'.
1276 unless defined $pager;
1280 We set up the command to be used to access the man pages, the command
1281 recall character (C<!> unless otherwise defined) and the shell escape
1282 character (C<!> unless otherwise defined). Yes, these do conflict, and
1283 neither works in the debugger at the moment.
1289 # Set up defaults for command recall and shell escape (note:
1290 # these currently don't work in linemode debugging).
1291 &recallCommand("!") unless defined $prc;
1292 &shellBang("!") unless defined $psh;
1296 We then set up the gigantic string containing the debugger help.
1297 We also set the limit on the number of arguments we'll display during a
1304 # If we didn't get a default for the length of eval/stack trace args,
1306 $maxtrace = 400 unless defined $maxtrace;
1308 =head2 SETTING UP THE DEBUGGER GREETING
1310 The debugger I<greeting> helps to inform the user how many debuggers are
1311 running, and whether the current debugger is the primary or a child.
1313 If we are the primary, we just hang onto our pid so we'll have it when
1314 or if we start a child debugger. If we are a child, we'll set things up
1315 so we'll have a unique greeting and so the parent will give us our own
1318 We save the current contents of the C<PERLDB_PIDS> environment variable
1319 because we mess around with it. We'll also need to hang onto it because
1320 we'll need it if we restart.
1322 Child debuggers make a label out of the current PID structure recorded in
1323 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1324 yet so the parent will give them one later via C<resetterm()>.
1328 # Save the current contents of the environment; we're about to
1329 # much with it. We'll need this if we have to restart.
1330 $ini_pids = $ENV{PERLDB_PIDS};
1332 if ( defined $ENV{PERLDB_PIDS} ) {
1334 # We're a child. Make us a label out of the current PID structure
1335 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1336 # a term yet so the parent will give us one later via resetterm().
1338 my $env_pids = $ENV{PERLDB_PIDS};
1339 $pids = "[$env_pids]";
1341 # Unless we are on OpenVMS, all programs under the DCL shell run under
1344 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1348 $ENV{PERLDB_PIDS} .= "->$$";
1352 } ## end if (defined $ENV{PERLDB_PIDS...
1355 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1356 # child debugger, and mark us as the parent, so we'll know to set up
1357 # more TTY's is we have to.
1358 $ENV{PERLDB_PIDS} = "$$";
1365 # Sets up $emacs as a synonym for $slave_editor.
1366 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1368 =head2 READING THE RC FILE
1370 The debugger will read a file of initialization options if supplied. If
1371 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1375 # As noted, this test really doesn't check accurately that the debugger
1376 # is running at a terminal or not.
1378 my $dev_tty = '/dev/tty';
1379 $dev_tty = 'TT:' if ($^O eq 'VMS');
1380 if ( -e $dev_tty ) { # this is the wrong metric!
1381 $rcfile = ".perldb";
1384 $rcfile = "perldb.ini";
1389 The debugger does a safety test of the file to be read. It must be owned
1390 either by the current user or root, and must only be writable by the owner.
1394 # This wraps a safety test around "do" to read and evaluate the init file.
1396 # This isn't really safe, because there's a race
1397 # between checking and opening. The solution is to
1398 # open and fstat the handle, but then you have to read and
1399 # eval the contents. But then the silly thing gets
1400 # your lexical scope, which is unfortunate at best.
1404 # Just exactly what part of the word "CORE::" don't you understand?
1405 local $SIG{__WARN__};
1406 local $SIG{__DIE__};
1408 unless ( is_safe_file($file) ) {
1409 CORE::warn <<EO_GRIPE;
1410 perldb: Must not source insecure rcfile $file.
1411 You or the superuser must be the owner, and it must not
1412 be writable by anyone but its owner.
1415 } ## end unless (is_safe_file($file...
1418 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1419 } ## end sub safe_do
1421 # This is the safety test itself.
1423 # Verifies that owner is either real user or superuser and that no
1424 # one but owner may write to it. This function is of limited use
1425 # when called on a path instead of upon a handle, because there are
1426 # no guarantees that filename (by dirent) whose file (by ino) is
1427 # eventually accessed is the same as the one tested.
1428 # Assumes that the file's existence is not in doubt.
1431 stat($path) || return; # mysteriously vaporized
1432 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1434 return 0 if $uid != 0 && $uid != $<;
1435 return 0 if $mode & 022;
1437 } ## end sub is_safe_file
1439 # If the rcfile (whichever one we decided was the right one to read)
1440 # exists, we safely do it.
1442 safe_do("./$rcfile");
1445 # If there isn't one here, try the user's home directory.
1446 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1447 safe_do("$ENV{HOME}/$rcfile");
1450 # Else try the login directory.
1451 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1452 safe_do("$ENV{LOGDIR}/$rcfile");
1455 # If the PERLDB_OPTS variable has options in it, parse those out next.
1456 if ( defined $ENV{PERLDB_OPTS} ) {
1457 parse_options( $ENV{PERLDB_OPTS} );
1462 The last thing we do during initialization is determine which subroutine is
1463 to be used to obtain a new terminal when a new debugger is started. Right now,
1464 the debugger only handles X Windows, OS/2, and Mac OS X (darwin).
1468 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1469 # Works if you're running an xterm or xterm-like window, or you're on
1470 # OS/2, or on Mac OS X. This may need some expansion.
1472 if (not defined &get_fork_TTY) # only if no routine exists
1474 if (defined $ENV{TERM} # If we know what kind
1475 # of terminal this is,
1476 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1477 and defined $ENV{DISPLAY} # and what display it's on,
1480 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1482 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1483 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1485 elsif ( $^O eq 'darwin' # If this is Mac OS X
1486 and defined $ENV{TERM_PROGRAM} # and we're running inside
1487 and $ENV{TERM_PROGRAM}
1488 eq 'Apple_Terminal' # Terminal.app
1491 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1493 } ## end if (not defined &get_fork_TTY...
1495 # untaint $^O, which may have been tainted by the last statement.
1496 # see bug [perl #24674]
1500 # Here begin the unreadable code. It needs fixing.
1502 =head2 RESTART PROCESSING
1504 This section handles the restart command. When the C<R> command is invoked, it
1505 tries to capture all of the state it can into environment variables, and
1506 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1507 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1508 the R command stuffed into the environment variables.
1510 PERLDB_RESTART - flag only, contains no restart data itself.
1511 PERLDB_HIST - command history, if it's available
1512 PERLDB_ON_LOAD - breakpoints set by the rc file
1513 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1514 PERLDB_VISITED - files that had breakpoints
1515 PERLDB_FILE_... - breakpoints for a file
1516 PERLDB_OPT - active options
1517 PERLDB_INC - the original @INC
1518 PERLDB_PRETYPE - preprompt debugger actions
1519 PERLDB_PRE - preprompt Perl code
1520 PERLDB_POST - post-prompt Perl code
1521 PERLDB_TYPEAHEAD - typeahead captured by readline()
1523 We chug through all these variables and plug the values saved in them
1524 back into the appropriate spots in the debugger.
1528 if ( exists $ENV{PERLDB_RESTART} ) {
1530 # We're restarting, so we don't need the flag that says to restart anymore.
1531 delete $ENV{PERLDB_RESTART};
1534 @hist = get_list('PERLDB_HIST');
1535 %break_on_load = get_list("PERLDB_ON_LOAD");
1536 %postponed = get_list("PERLDB_POSTPONE");
1540 share(%break_on_load);
1543 # restore breakpoints/actions
1544 my @had_breakpoints = get_list("PERLDB_VISITED");
1545 for ( 0 .. $#had_breakpoints ) {
1546 my %pf = get_list("PERLDB_FILE_$_");
1547 $postponed_file{ $had_breakpoints[$_] } = \%pf if %pf;
1551 my %opt = get_list("PERLDB_OPT");
1553 while ( ( $opt, $val ) = each %opt ) {
1554 $val =~ s/[\\\']/\\$1/g;
1555 parse_options("$opt'$val'");
1558 # restore original @INC
1559 @INC = get_list("PERLDB_INC");
1562 # return pre/postprompt actions and typeahead buffer
1563 $pretype = [ get_list("PERLDB_PRETYPE") ];
1564 $pre = [ get_list("PERLDB_PRE") ];
1565 $post = [ get_list("PERLDB_POST") ];
1566 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1567 } ## end if (exists $ENV{PERLDB_RESTART...
1569 =head2 SETTING UP THE TERMINAL
1571 Now, we'll decide how the debugger is going to interact with the user.
1572 If there's no TTY, we set the debugger to run non-stop; there's not going
1573 to be anyone there to enter commands.
1584 If there is a TTY, we have to determine who it belongs to before we can
1585 proceed. If this is a slave editor or graphical debugger (denoted by
1586 the first command-line switch being '-emacs'), we shift this off and
1587 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1593 # Is Perl being run from a slave editor or graphical debugger?
1594 # If so, don't use readline, and set $slave_editor = 1.
1596 ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) );
1597 $rl = 0, shift(@main::ARGV) if $slave_editor;
1599 #require Term::ReadLine;
1603 We then determine what the console should be on various systems:
1607 =item * Cygwin - We use C<stdin> instead of a separate device.
1611 if ( $^O eq 'cygwin' ) {
1613 # /dev/tty is binary. use stdin for textmode
1617 =item * Unix - use C</dev/tty>.
1621 elsif ( -e "/dev/tty" ) {
1622 $console = "/dev/tty";
1625 =item * Windows or MSDOS - use C<con>.
1629 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1633 =item * MacOS - use C<Dev:Console:Perl Debug> if this is the MPW version; C<Dev:
1636 Note that Mac OS X returns C<darwin>, not C<MacOS>. Also note that the debugger doesn't do anything special for C<darwin>. Maybe it should.
1640 elsif ( $^O eq 'MacOS' ) {
1641 if ( $MacPerl::Version !~ /MPW/ ) {
1643 "Dev:Console:Perl Debug"; # Separate window for application
1646 $console = "Dev:Console";
1648 } ## end elsif ($^O eq 'MacOS')
1650 =item * VMS - use C<sys$command>.
1656 # everything else is ...
1657 $console = "sys\$command";
1664 Several other systems don't use a specific console. We C<undef $console>
1665 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1666 with a slave editor, Epoc).
1670 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1672 # /dev/tty is binary. use stdin for textmode
1676 if ( $^O eq 'NetWare' ) {
1678 # /dev/tty is binary. use stdin for textmode
1682 # In OS/2, we need to use STDIN to get textmode too, even though
1683 # it pretty much looks like Unix otherwise.
1684 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1689 # EPOC also falls into the 'got to use STDIN' camp.
1690 if ( $^O eq 'epoc' ) {
1696 If there is a TTY hanging around from a parent, we use that as the console.
1700 $console = $tty if defined $tty;
1702 =head2 SOCKET HANDLING
1704 The debugger is capable of opening a socket and carrying out a debugging
1705 session over the socket.
1707 If C<RemotePort> was defined in the options, the debugger assumes that it
1708 should try to start a debugging session on that port. It builds the socket
1709 and then tries to connect the input and output filehandles to it.
1713 # Handle socket stuff.
1715 if ( defined $remoteport ) {
1717 # If RemotePort was defined in the options, connect input and output
1720 $OUT = new IO::Socket::INET(
1722 PeerAddr => $remoteport,
1725 if ( !$OUT ) { die "Unable to connect to remote host: $remoteport\n"; }
1727 } ## end if (defined $remoteport)
1731 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1732 this is probably a situation where multiple debuggers are running (for example,
1733 a backticked command that starts up another debugger). We create a new IN and
1734 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1742 # Two debuggers running (probably a system or a backtick that invokes
1743 # the debugger itself under the running one). create a new IN and OUT
1744 # filehandle, and do the necessary mojo to create a new tty if we
1745 # know how, and we can.
1746 create_IN_OUT(4) if $CreateTTY & 4;
1749 # If we have a console, check to see if there are separate ins and
1750 # outs to open. (They are assumed identical if not.)
1752 my ( $i, $o ) = split /,/, $console;
1753 $o = $i unless defined $o;
1755 # read/write on in, or just read, or read on STDIN.
1757 || open( IN, "<$i" )
1758 || open( IN, "<&STDIN" );
1760 # read/write/create/clobber out, or write/create/clobber out,
1761 # or merge with STDERR, or merge with STDOUT.
1763 || open( OUT, ">$o" )
1764 || open( OUT, ">&STDERR" )
1765 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1767 } ## end if ($console)
1768 elsif ( not defined $console ) {
1770 # No console. Open STDIN.
1771 open( IN, "<&STDIN" );
1773 # merge with STDERR, or with STDOUT.
1774 open( OUT, ">&STDERR" )
1775 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1776 $console = 'STDIN/OUT';
1777 } ## end elsif (not defined $console)
1779 # Keep copies of the filehandles so that when the pager runs, it
1780 # can close standard input without clobbering ours.
1781 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1782 } ## end elsif (from if(defined $remoteport))
1784 # Unbuffer DB::OUT. We need to see responses right away.
1785 my $previous = select($OUT);
1786 $| = 1; # for DB::OUT
1789 # Line info goes to debugger output unless pointed elsewhere.
1790 # Pointing elsewhere makes it possible for slave editors to
1791 # keep track of file and position. We have both a filehandle
1792 # and a I/O description to keep track of.
1793 $LINEINFO = $OUT unless defined $LINEINFO;
1794 $lineinfo = $console unless defined $lineinfo;
1795 # share($LINEINFO); # <- unable to share globs
1800 To finish initialization, we show the debugger greeting,
1801 and then call the C<afterinit()> subroutine if there is one.
1805 # Show the debugger greeting.
1806 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1807 unless ($runnonstop) {
1810 if ( $term_pid eq '-1' ) {
1811 print $OUT "\nDaughter DB session started...\n";
1814 print $OUT "\nLoading DB routines from $header\n";
1817 $slave_editor ? "enabled" : "available", ".\n"
1820 "\nEnter h or `h h' for help, or `$doccmd perldebug' for more help.\n\n";
1821 } ## end else [ if ($term_pid eq '-1')
1822 } ## end unless ($runnonstop)
1823 } ## end else [ if ($notty)
1825 # XXX This looks like a bug to me.
1826 # Why copy to @ARGS and then futz with @args?
1829 # Make sure backslashes before single quotes are stripped out, and
1830 # keep args unless they are numeric (XXX why?)
1831 # s/\'/\\\'/g; # removed while not justified understandably
1832 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1835 # If there was an afterinit() sub defined, call it. It will get
1836 # executed in our scope, so it can fiddle with debugger globals.
1837 if ( defined &afterinit ) { # May be defined in $rcfile
1841 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1844 ############################################################ Subroutines
1850 This gigantic subroutine is the heart of the debugger. Called before every
1851 statement, its job is to determine if a breakpoint has been reached, and
1852 stop if so; read commands from the user, parse them, and execute
1853 them, and then send execution off to the next statement.
1855 Note that the order in which the commands are processed is very important;
1856 some commands earlier in the loop will actually alter the C<$cmd> variable
1857 to create other commands to be executed later. This is all highly I<optimized>
1858 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1859 see what's happening in any given command.
1865 # lock the debugger and get the thread id for the prompt
1868 if ($ENV{PERL5DB_THREADED}) {
1869 $tid = eval { "[".threads->tid."]" };
1872 # Check for whether we should be running continuously or not.
1873 # _After_ the perl program is compiled, $single is set to 1:
1874 if ( $single and not $second_time++ ) {
1876 # Options say run non-stop. Run until we get an interrupt.
1877 if ($runnonstop) { # Disable until signal
1878 # If there's any call stack in place, turn off single
1879 # stepping into subs throughout the stack.
1880 for ( $i = 0 ; $i <= $stack_depth ; ) {
1881 $stack[ $i++ ] &= ~1;
1884 # And we are now no longer in single-step mode.
1887 # If we simply returned at this point, we wouldn't get
1888 # the trace info. Fall on through.
1890 } ## end if ($runnonstop)
1892 elsif ($ImmediateStop) {
1894 # We are supposed to stop here; XXX probably a break.
1895 $ImmediateStop = 0; # We've processed it; turn it off
1896 $signal = 1; # Simulate an interrupt to force
1897 # us into the command loop
1899 } ## end if ($single and not $second_time...
1901 # If we're in single-step mode, or an interrupt (real or fake)
1902 # has occurred, turn off non-stop mode.
1903 $runnonstop = 0 if $single or $signal;
1905 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1906 # The code being debugged may have altered them.
1909 # Since DB::DB gets called after every line, we can use caller() to
1910 # figure out where we last were executing. Sneaky, eh? This works because
1911 # caller is returning all the extra information when called from the
1913 local ( $package, $filename, $line ) = caller;
1914 local $filename_ini = $filename;
1916 # set up the context for DB::eval, so it can properly execute
1917 # code on behalf of the user. We add the package in so that the
1918 # code is eval'ed in the proper package (not in the debugger!).
1919 local $usercontext =
1920 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' . "package $package;";
1922 # Create an alias to the active file magical array to simplify
1924 local (*dbline) = $main::{ '_<' . $filename };
1926 # we need to check for pseudofiles on Mac OS (these are files
1927 # not attached to a filename, but instead stored in Dev:Pseudo)
1928 if ( $^O eq 'MacOS' && $#dbline < 0 ) {
1929 $filename_ini = $filename = 'Dev:Pseudo';
1930 *dbline = $main::{ '_<' . $filename };
1933 # Last line in the program.
1934 local $max = $#dbline;
1936 # if we have something here, see if we should break.
1938 && ( ( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1941 # Stop if the stop criterion says to just stop.
1942 if ( $stop eq '1' ) {
1946 # It's a conditional stop; eval it in the user's context and
1947 # see if we should stop. If so, remove the one-time sigil.
1949 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1951 $dbline{$line} =~ s/;9($|\0)/$1/;
1953 } ## end if ($dbline{$line} && ...
1955 # Preserve the current stop-or-not, and see if any of the W
1956 # (watch expressions) has changed.
1957 my $was_signal = $signal;
1959 # If we have any watch expressions ...
1961 for ( my $n = 0 ; $n <= $#to_watch ; $n++ ) {
1962 $evalarg = $to_watch[$n];
1963 local $onetimeDump; # Tell DB::eval() to not output results
1965 # Fix context DB::eval() wants to return an array, but
1966 # we need a scalar here.
1967 my ($val) = join( "', '", &eval );
1968 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
1971 if ( $val ne $old_watch[$n] ) {
1973 # Yep! Show the difference, and fake an interrupt.
1976 Watchpoint $n:\t$to_watch[$n] changed:
1977 old value:\t$old_watch[$n]
1980 $old_watch[$n] = $val;
1981 } ## end if ($val ne $old_watch...
1982 } ## end for (my $n = 0 ; $n <= ...
1983 } ## end if ($trace & 2)
1985 =head2 C<watchfunction()>
1987 C<watchfunction()> is a function that can be defined by the user; it is a
1988 function which will be run on each entry to C<DB::DB>; it gets the
1989 current package, filename, and line as its parameters.
1991 The watchfunction can do anything it likes; it is executing in the
1992 debugger's context, so it has access to all of the debugger's internal
1993 data structures and functions.
1995 C<watchfunction()> can control the debugger's actions. Any of the following
1996 will cause the debugger to return control to the user's program after
1997 C<watchfunction()> executes:
2003 Returning a false value from the C<watchfunction()> itself.
2007 Altering C<$single> to a false value.
2011 Altering C<$signal> to a false value.
2015 Turning off the C<4> bit in C<$trace> (this also disables the
2016 check for C<watchfunction()>. This can be done with
2024 # If there's a user-defined DB::watchfunction, call it with the
2025 # current package, filename, and line. The function executes in
2027 if ( $trace & 4 ) { # User-installed watch
2029 if watchfunction( $package, $filename, $line )
2032 and not( $trace & ~4 );
2033 } ## end if ($trace & 4)
2035 # Pick up any alteration to $signal in the watchfunction, and
2036 # turn off the signal now.
2037 $was_signal = $signal;
2040 =head2 GETTING READY TO EXECUTE COMMANDS
2042 The debugger decides to take control if single-step mode is on, the
2043 C<t> command was entered, or the user generated a signal. If the program
2044 has fallen off the end, we set things up so that entering further commands
2045 won't cause trouble, and we say that the program is over.
2049 # Check to see if we should grab control ($single true,
2050 # trace set appropriately, or we got a signal).
2051 if ( $single || ( $trace & 1 ) || $was_signal ) {
2053 # Yes, grab control.
2054 if ($slave_editor) {
2056 # Tell the editor to update its position.
2057 $position = "\032\032$filename:$line:0\n";
2058 print_lineinfo($position);
2063 Special check: if we're in package C<DB::fake>, we've gone through the
2064 C<END> block at least once. We set up everything so that we can continue
2065 to enter commands and have a valid context to be in.
2069 elsif ( $package eq 'DB::fake' ) {
2071 # Fallen off the end already.
2074 Debugged program terminated. Use B<q> to quit or B<R> to restart,
2075 use B<o> I<inhibit_exit> to avoid stopping after program termination,
2076 B<h q>, B<h R> or B<h o> to get additional info.
2079 # Set the DB::eval context appropriately.
2082 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;'
2083 . "package $package;"; # this won't let them modify, alas
2084 } ## end elsif ($package eq 'DB::fake')
2088 If the program hasn't finished executing, we scan forward to the
2089 next executable line, print that out, build the prompt from the file and line
2090 number information, and print that.
2096 # Still somewhere in the midst of execution. Set up the
2098 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
2099 # Perl 5 ones (sorry, we don't print Klingon
2102 $prefix = $sub =~ /::/ ? "" : "${'package'}::";
2103 $prefix .= "$sub($filename:";
2104 $after = ( $dbline[$line] =~ /\n$/ ? '' : "\n" );
2106 # Break up the prompt if it's really long.
2107 if ( length($prefix) > 30 ) {
2108 $position = "$prefix$line):\n$line:\t$dbline[$line]$after";
2114 $position = "$prefix$line$infix$dbline[$line]$after";
2117 # Print current line info, indenting if necessary.
2119 print_lineinfo( ' ' x $stack_depth,
2120 "$line:\t$dbline[$line]$after" );
2123 print_lineinfo($position);
2126 # Scan forward, stopping at either the end or the next
2128 for ( $i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i )
2131 # Drop out on null statements, block closers, and comments.
2132 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/;
2134 # Drop out if the user interrupted us.
2137 # Append a newline if the line doesn't have one. Can happen
2138 # in eval'ed text, for instance.
2139 $after = ( $dbline[$i] =~ /\n$/ ? '' : "\n" );
2141 # Next executable line.
2142 $incr_pos = "$prefix$i$infix$dbline[$i]$after";
2143 $position .= $incr_pos;
2146 # Print it indented if tracing is on.
2147 print_lineinfo( ' ' x $stack_depth,
2148 "$i:\t$dbline[$i]$after" );
2151 print_lineinfo($incr_pos);
2153 } ## end for ($i = $line + 1 ; $i...
2154 } ## end else [ if ($slave_editor)
2155 } ## end if ($single || ($trace...
2159 If there's an action to be executed for the line we stopped at, execute it.
2160 If there are any preprompt actions, execute those as well.
2164 # If there's an action, do it now.
2165 $evalarg = $action, &eval if $action;
2167 # Are we nested another level (e.g., did we evaluate a function
2168 # that had a breakpoint in it at the debugger prompt)?
2169 if ( $single || $was_signal ) {
2171 # Yes, go down a level.
2172 local $level = $level + 1;
2174 # Do any pre-prompt actions.
2175 foreach $evalarg (@$pre) {
2179 # Complain about too much recursion if we passed the limit.
2180 print $OUT $stack_depth . " levels deep in subroutine calls!\n"
2183 # The line we're currently on. Set $incr to -1 to stay here
2184 # until we get a command that tells us to advance.
2186 $incr = -1; # for backward motion.
2188 # Tack preprompt debugger actions ahead of any actual input.
2189 @typeahead = ( @$pretype, @typeahead );
2191 =head2 WHERE ARE WE?
2193 XXX Relocate this section?
2195 The debugger normally shows the line corresponding to the current line of
2196 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2197 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2199 C<$incr> controls by how many lines the I<current> line should move forward
2200 after a command is executed. If set to -1, this indicates that the I<current>
2201 line shouldn't change.
2203 C<$start> is the I<current> line. It is used for things like knowing where to
2204 move forwards or backwards from when doing an C<L> or C<-> command.
2206 C<$max> tells the debugger where the last line of the current file is. It's
2207 used to terminate loops most often.
2209 =head2 THE COMMAND LOOP
2211 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2218 The outer part of the loop, starting at the C<CMD> label. This loop
2219 reads a command and then executes it.
2223 The inner part of the loop, starting at the C<PIPE> label. This part
2224 is wholly contained inside the C<CMD> block and only executes a command.
2225 Used to handle commands running inside a pager.
2229 So why have two labels to restart the loop? Because sometimes, it's easier to
2230 have a command I<generate> another command and then re-execute the loop to do
2231 the new command. This is faster, but perhaps a bit more convoluted.
2235 # The big command dispatch loop. It keeps running until the
2236 # user yields up control again.
2238 # If we have a terminal for input, and we get something back
2239 # from readline(), keep on processing.
2243 # We have a terminal, or can get one ...
2244 ( $term || &setterm ),
2246 # ... and it belogs to this PID or we get one for this PID ...
2247 ( $term_pid == $$ or resetterm(1) ),
2249 # ... and we got a line of command input ...
2252 "$pidprompt $tid DB"
2255 . ( '>' x $level ) . " "
2262 # ... try to execute the input as debugger commands.
2264 # Don't stop running.
2267 # No signal is active.
2270 # Handle continued commands (ending with \):
2271 $cmd =~ s/\\$/\n/ && do {
2272 $cmd .= &readline(" cont: ");
2276 =head4 The null command
2278 A newline entered by itself means I<re-execute the last command>. We grab the
2279 command out of C<$laststep> (where it was recorded previously), and copy it
2280 back into C<$cmd> to be executed below. If there wasn't any previous command,
2281 we'll do nothing below (no command will match). If there was, we also save it
2282 in the command history and fall through to allow the command parsing to pick
2287 # Empty input means repeat the last command.
2288 $cmd =~ /^$/ && ( $cmd = $laststep );
2289 chomp($cmd); # get rid of the annoying extra newline
2290 push( @hist, $cmd ) if length($cmd) > 1;
2291 push( @truehist, $cmd );
2295 # This is a restart point for commands that didn't arrive
2296 # via direct user input. It allows us to 'redo PIPE' to
2297 # re-execute command processing without reading a new command.
2299 $cmd =~ s/^\s+//s; # trim annoying leading whitespace
2300 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace
2301 ($i) = split( /\s+/, $cmd );
2303 =head3 COMMAND ALIASES
2305 The debugger can create aliases for commands (these are stored in the
2306 C<%alias> hash). Before a command is executed, the command loop looks it up
2307 in the alias hash and substitutes the contents of the alias for the command,
2308 completely replacing it.
2312 # See if there's an alias for the command, and set it up if so.
2315 # Squelch signal handling; we want to keep control here
2316 # if something goes loco during the alias eval.
2317 local $SIG{__DIE__};
2318 local $SIG{__WARN__};
2320 # This is a command, so we eval it in the DEBUGGER's
2321 # scope! Otherwise, we can't see the special debugger
2322 # variables, or get to the debugger's subs. (Well, we
2323 # _could_, but why make it even more complicated?)
2324 eval "\$cmd =~ $alias{$i}";
2327 print $OUT "Couldn't evaluate `$i' alias: $@";
2330 } ## end if ($alias{$i})
2332 =head3 MAIN-LINE COMMANDS
2334 All of these commands work up to and after the program being debugged has
2339 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2340 try to execute further, cleaning any restart-related stuff out of the
2341 environment, and executing with the last value of C<$?>.
2345 $cmd =~ /^q$/ && do {
2353 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2357 $cmd =~ /^t$/ && do {
2360 print $OUT "Trace = "
2361 . ( ( $trace & 1 ) ? "on" : "off" ) . "\n";
2365 =head4 C<S> - list subroutines matching/not matching a pattern
2367 Walks through C<%sub>, checking to see whether or not to print the name.
2371 $cmd =~ /^S(\s+(!)?(.+))?$/ && do {
2373 $Srev = defined $2; # Reverse scan?
2374 $Spatt = $3; # The pattern (if any) to use.
2375 $Snocheck = !defined $1; # No args - print all subs.
2377 # Need to make these sane here.
2381 # Search through the debugger's magical hash of subs.
2382 # If $nocheck is true, just print the sub name.
2383 # Otherwise, check it against the pattern. We then use
2384 # the XOR trick to reverse the condition as required.
2385 foreach $subname ( sort( keys %sub ) ) {
2386 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2387 print $OUT $subname, "\n";
2393 =head4 C<X> - list variables in current package
2395 Since the C<V> command actually processes this, just change this to the
2396 appropriate C<V> command and fall through.
2400 $cmd =~ s/^X\b/V $package/;
2402 =head4 C<V> - list variables
2404 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2408 # Bare V commands get the currently-being-debugged package
2410 $cmd =~ /^V$/ && do {
2411 $cmd = "V $package";
2414 # V - show variables in package.
2415 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
2417 # Save the currently selected filehandle and
2418 # force output to debugger's filehandle (dumpvar
2419 # just does "print" for output).
2420 local ($savout) = select($OUT);
2422 # Grab package name and variables to dump.
2424 @vars = split( ' ', $2 );
2426 # If main::dumpvar isn't here, get it.
2427 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
2428 if ( defined &main::dumpvar ) {
2430 # We got it. Turn off subroutine entry/exit messages
2431 # for the moment, along with return values.
2435 # must detect sigpipe failures - not catching
2436 # then will cause the debugger to die.
2440 defined $option{dumpDepth}
2441 ? $option{dumpDepth}
2442 : -1, # assume -1 unless specified
2447 # The die doesn't need to include the $@, because
2448 # it will automatically get propagated for us.
2450 die unless $@ =~ /dumpvar print failed/;
2452 } ## end if (defined &main::dumpvar)
2455 # Couldn't load dumpvar.
2456 print $OUT "dumpvar.pl not available.\n";
2459 # Restore the output filehandle, and go round again.
2464 =head4 C<x> - evaluate and print an expression
2466 Hands the expression off to C<DB::eval>, setting it up to print the value
2467 via C<dumpvar.pl> instead of just printing it directly.
2471 $cmd =~ s/^x\b/ / && do { # Remainder gets done by DB::eval()
2472 $onetimeDump = 'dump'; # main::dumpvar shows the output
2474 # handle special "x 3 blah" syntax XXX propagate
2475 # doc back to special variables.
2476 if ( $cmd =~ s/^\s*(\d+)(?=\s)/ / ) {
2477 $onetimedumpDepth = $1;
2481 =head4 C<m> - print methods
2483 Just uses C<DB::methods> to determine what methods are available.
2487 $cmd =~ s/^m\s+([\w:]+)\s*$/ / && do {
2492 # m expr - set up DB::eval to do the work
2493 $cmd =~ s/^m\b/ / && do { # Rest gets done by DB::eval()
2494 $onetimeDump = 'methods'; # method output gets used there
2497 =head4 C<f> - switch files
2501 $cmd =~ /^f\b\s*(.*)/ && do {
2505 # help for no arguments (old-style was return from sub).
2508 "The old f command is now the r command.\n"; # hint
2509 print $OUT "The new f command switches filenames.\n";
2511 } ## end if (!$file)
2513 # if not in magic file list, try a close match.
2514 if ( !defined $main::{ '_<' . $file } ) {
2515 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2517 $try = substr( $try, 2 );
2518 print $OUT "Choosing $try matching `$file':\n";
2521 } ## end if (($try) = grep(m#^_<.*$file#...
2522 } ## end if (!defined $main::{ ...
2524 # If not successfully switched now, we failed.
2525 if ( !defined $main::{ '_<' . $file } ) {
2526 print $OUT "No file matching `$file' is loaded.\n";
2530 # We switched, so switch the debugger internals around.
2531 elsif ( $file ne $filename ) {
2532 *dbline = $main::{ '_<' . $file };
2537 } ## end elsif ($file ne $filename)
2539 # We didn't switch; say we didn't.
2541 print $OUT "Already in $file.\n";
2546 =head4 C<.> - return to last-executed line.
2548 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2549 and then we look up the line in the magical C<%dbline> hash.
2554 $cmd =~ /^\.$/ && do {
2555 $incr = -1; # stay at current line
2557 # Reset everything to the old location.
2559 $filename = $filename_ini;
2560 *dbline = $main::{ '_<' . $filename };
2564 print_lineinfo($position);
2568 =head4 C<-> - back one window
2570 We change C<$start> to be one window back; if we go back past the first line,
2571 we set it to be the first line. We ser C<$incr> to put us back at the
2572 currently-executing line, and then put a C<l $start +> (list one window from
2573 C<$start>) in C<$cmd> to be executed later.
2577 # - - back a window.
2578 $cmd =~ /^-$/ && do {
2580 # back up by a window; go to 1 if back too far.
2581 $start -= $incr + $window + 1;
2582 $start = 1 if $start <= 0;
2583 $incr = $window - 1;
2585 # Generate and execute a "l +" command (handled below).
2586 $cmd = 'l ' . ($start) . '+';
2589 =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>, {, {{>
2591 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2592 problems, most notably that the default case of several commands destroying
2593 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2594 retain the old commands for those who were used to using them or who preferred
2595 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2596 deal with them instead of processing them in-line.
2600 # All of these commands were remapped in perl 5.8.0;
2601 # we send them off to the secondary dispatcher (see below).
2602 $cmd =~ /^([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so && do {
2603 &cmd_wrapper( $1, $2, $line );
2607 =head4 C<y> - List lexicals in higher scope
2609 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2610 above the current one and then displays then using C<dumpvar.pl>.
2614 $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/ && do {
2616 # See if we've got the necessary support.
2617 eval { require PadWalker; PadWalker->VERSION(0.08) }
2620 ? "PadWalker module not found - please install\n"
2625 # Load up dumpvar if we don't have it. If we can, that is.
2626 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
2627 defined &main::dumpvar
2628 or print $OUT "dumpvar.pl not available.\n"
2631 # Got all the modules we need. Find them and print them.
2632 my @vars = split( ' ', $2 || '' );
2635 my $h = eval { PadWalker::peek_my( ( $1 || 0 ) + 1 ) };
2637 # Oops. Can't find it.
2638 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2640 # Show the desired vars with dumplex().
2641 my $savout = select($OUT);
2643 # Have dumplex dump the lexicals.
2644 dumpvar::dumplex( $_, $h->{$_},
2645 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
2652 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2654 All of the commands below this point don't work after the program being
2655 debugged has ended. All of them check to see if the program has ended; this
2656 allows the commands to be relocated without worrying about a 'line of
2657 demarcation' above which commands can be entered anytime, and below which
2660 =head4 C<n> - single step, but don't trace down into subs
2662 Done by setting C<$single> to 2, which forces subs to execute straight through
2663 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2664 so a null command knows what to re-execute.
2669 $cmd =~ /^n$/ && do {
2670 end_report(), next CMD if $finished and $level <= 1;
2672 # Single step, but don't enter subs.
2675 # Save for empty command (repeat last).
2680 =head4 C<s> - single-step, entering subs
2682 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2683 subs. Also saves C<s> as C<$lastcmd>.
2688 $cmd =~ /^s$/ && do {
2690 # Get out and restart the command loop if program
2692 end_report(), next CMD if $finished and $level <= 1;
2694 # Single step should enter subs.
2697 # Save for empty command (repeat last).
2702 =head4 C<c> - run continuously, setting an optional breakpoint
2704 Most of the code for this command is taken up with locating the optional
2705 breakpoint, which is either a subroutine name or a line number. We set
2706 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2707 in this and all call levels above this one.
2711 # c - start continuous execution.
2712 $cmd =~ /^c\b\s*([\w:]*)\s*$/ && do {
2714 # Hey, show's over. The debugged program finished
2715 # executing already.
2716 end_report(), next CMD if $finished and $level <= 1;
2718 # Capture the place to put a one-time break.
2721 # Probably not needed, since we finish an interactive
2722 # sub-session anyway...
2723 # local $filename = $filename;
2724 # local *dbline = *dbline; # XXX Would this work?!
2726 # The above question wonders if localizing the alias
2727 # to the magic array works or not. Since it's commented
2728 # out, we'll just leave that to speculation for now.
2730 # If the "subname" isn't all digits, we'll assume it
2731 # is a subroutine name, and try to find it.
2732 if ( $subname =~ /\D/ ) { # subroutine name
2733 # Qualify it to the current package unless it's
2734 # already qualified.
2735 $subname = $package . "::" . $subname
2736 unless $subname =~ /::/;
2738 # find_sub will return "file:line_number" corresponding
2739 # to where the subroutine is defined; we call find_sub,
2740 # break up the return value, and assign it in one
2742 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2744 # Force the line number to be numeric.
2747 # If we got a line number, we found the sub.
2750 # Switch all the debugger's internals around so
2751 # we're actually working with that file.
2753 *dbline = $main::{ '_<' . $filename };
2755 # Mark that there's a breakpoint in this file.
2756 $had_breakpoints{$filename} |= 1;
2758 # Scan forward to the first executable line
2759 # after the 'sub whatever' line.
2761 ++$i while $dbline[$i] == 0 && $i < $max;
2764 # We didn't find a sub by that name.
2766 print $OUT "Subroutine $subname not found.\n";
2769 } ## end if ($subname =~ /\D/)
2771 # At this point, either the subname was all digits (an
2772 # absolute line-break request) or we've scanned through
2773 # the code following the definition of the sub, looking
2774 # for an executable, which we may or may not have found.
2776 # If $i (which we set $subname from) is non-zero, we
2777 # got a request to break at some line somewhere. On
2778 # one hand, if there wasn't any real subroutine name
2779 # involved, this will be a request to break in the current
2780 # file at the specified line, so we have to check to make
2781 # sure that the line specified really is breakable.
2783 # On the other hand, if there was a subname supplied, the
2784 # preceding block has moved us to the proper file and
2785 # location within that file, and then scanned forward
2786 # looking for the next executable line. We have to make
2787 # sure that one was found.
2789 # On the gripping hand, we can't do anything unless the
2790 # current value of $i points to a valid breakable line.
2795 if ( $dbline[$i] == 0 ) {
2796 print $OUT "Line $i not breakable.\n";
2800 # Yes. Set up the one-time-break sigil.
2801 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2804 # Turn off stack tracing from here up.
2805 for ( $i = 0 ; $i <= $stack_depth ; ) {
2806 $stack[ $i++ ] &= ~1;
2811 =head4 C<r> - return from a subroutine
2813 For C<r> to work properly, the debugger has to stop execution again
2814 immediately after the return is executed. This is done by forcing
2815 single-stepping to be on in the call level above the current one. If
2816 we are printing return values when a C<r> is executed, set C<$doret>
2817 appropriately, and force us out of the command loop.
2821 # r - return from the current subroutine.
2822 $cmd =~ /^r$/ && do {
2824 # Can't do anythign if the program's over.
2825 end_report(), next CMD if $finished and $level <= 1;
2827 # Turn on stack trace.
2828 $stack[$stack_depth] |= 1;
2830 # Print return value unless the stack is empty.
2831 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2835 =head4 C<T> - stack trace
2837 Just calls C<DB::print_trace>.
2841 $cmd =~ /^T$/ && do {
2842 print_trace( $OUT, 1 ); # skip DB
2846 =head4 C<w> - List window around current line.
2848 Just calls C<DB::cmd_w>.
2852 $cmd =~ /^w\b\s*(.*)/s && do { &cmd_w( 'w', $1 ); next CMD; };
2854 =head4 C<W> - watch-expression processing.
2856 Just calls C<DB::cmd_W>.
2860 $cmd =~ /^W\b\s*(.*)/s && do { &cmd_W( 'W', $1 ); next CMD; };
2862 =head4 C</> - search forward for a string in the source
2864 We take the argument and treat it as a pattern. If it turns out to be a
2865 bad one, we return the error we got from trying to C<eval> it and exit.
2866 If not, we create some code to do the search and C<eval> it so it can't
2871 $cmd =~ /^\/(.*)$/ && do {
2873 # The pattern as a string.
2876 # Remove the final slash.
2877 $inpat =~ s:([^\\])/$:$1:;
2879 # If the pattern isn't null ...
2880 if ( $inpat ne "" ) {
2882 # Turn of warn and die procesing for a bit.
2883 local $SIG{__DIE__};
2884 local $SIG{__WARN__};
2886 # Create the pattern.
2887 eval '$inpat =~ m' . "\a$inpat\a";
2890 # Oops. Bad pattern. No biscuit.
2891 # Print the eval error and go back for more
2897 } ## end if ($inpat ne "")
2899 # Set up to stop on wrap-around.
2902 # Don't move off the current line.
2905 # Done in eval so nothing breaks if the pattern
2906 # does something weird.
2909 # Move ahead one line.
2912 # Wrap if we pass the last line.
2913 $start = 1 if ($start > $max);
2915 # Stop if we have gotten back to this line again,
2916 last if ($start == $end);
2918 # A hit! (Note, though, that we are doing
2919 # case-insensitive matching. Maybe a qr//
2920 # expression would be better, so the user could
2921 # do case-sensitive matching if desired.
2922 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2923 if ($slave_editor) {
2924 # Handle proper escaping in the slave.
2925 print $OUT "\032\032$filename:$start:0\n";
2928 # Just print the line normally.
2929 print $OUT "$start:\t",$dbline[$start],"\n";
2931 # And quit since we found something.
2936 # If we wrapped, there never was a match.
2937 print $OUT "/$pat/: not found\n" if ( $start == $end );
2941 =head4 C<?> - search backward for a string in the source
2943 Same as for C</>, except the loop runs backwards.
2947 # ? - backward pattern search.
2948 $cmd =~ /^\?(.*)$/ && do {
2950 # Get the pattern, remove trailing question mark.
2952 $inpat =~ s:([^\\])\?$:$1:;
2954 # If we've got one ...
2955 if ( $inpat ne "" ) {
2957 # Turn off die & warn handlers.
2958 local $SIG{__DIE__};
2959 local $SIG{__WARN__};
2960 eval '$inpat =~ m' . "\a$inpat\a";
2964 # Ouch. Not good. Print the error.
2969 } ## end if ($inpat ne "")
2971 # Where we are now is where to stop after wraparound.
2974 # Don't move away from this line.
2977 # Search inside the eval to prevent pattern badness
2984 # Wrap if we pass the first line.
2986 $start = $max if ($start <= 0);
2988 # Quit if we get back where we started,
2989 last if ($start == $end);
2992 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2993 if ($slave_editor) {
2994 # Yep, follow slave editor requirements.
2995 print $OUT "\032\032$filename:$start:0\n";
2998 # Yep, just print normally.
2999 print $OUT "$start:\t",$dbline[$start],"\n";
3007 # Say we failed if the loop never found anything,
3008 print $OUT "?$pat?: not found\n" if ( $start == $end );
3012 =head4 C<$rc> - Recall command
3014 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
3015 that the terminal supports history). It find the the command required, puts it
3016 into C<$cmd>, and redoes the loop to execute it.
3020 # $rc - recall command.
3021 $cmd =~ /^$rc+\s*(-)?(\d+)?$/ && do {
3023 # No arguments, take one thing off history.
3024 pop(@hist) if length($cmd) > 1;
3026 # Relative (- found)?
3027 # Y - index back from most recent (by 1 if bare minus)
3028 # N - go to that particular command slot or the last
3029 # thing if nothing following.
3030 $i = $1 ? ( $#hist - ( $2 || 1 ) ) : ( $2 || $#hist );
3032 # Pick out the command desired.
3035 # Print the command to be executed and restart the loop
3036 # with that command in the buffer.
3037 print $OUT $cmd, "\n";
3041 =head4 C<$sh$sh> - C<system()> command
3043 Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
3044 C<STDOUT> from getting messed up.
3048 # $sh$sh - run a shell command (if it's all ASCII).
3049 # Can't run shell commands with Unicode in the debugger, hmm.
3050 $cmd =~ /^$sh$sh\s*([\x00-\xff]*)/ && do {
3057 =head4 C<$rc I<pattern> $rc> - Search command history
3059 Another command to manipulate C<@hist>: this one searches it with a pattern.
3060 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
3064 # $rc pattern $rc - find a command in the history.
3065 $cmd =~ /^$rc([^$rc].*)$/ && do {
3067 # Create the pattern to use.
3070 # Toss off last entry if length is >1 (and it always is).
3071 pop(@hist) if length($cmd) > 1;
3073 # Look backward through the history.
3074 for ( $i = $#hist ; $i ; --$i ) {
3076 # Stop if we find it.
3077 last if $hist[$i] =~ /$pat/;
3083 print $OUT "No such command!\n\n";
3087 # Found it. Put it in the buffer, print it, and process it.
3089 print $OUT $cmd, "\n";
3093 =head4 C<$sh> - Invoke a shell
3095 Uses C<DB::system> to invoke a shell.
3099 # $sh - start a shell.
3100 $cmd =~ /^$sh$/ && do {
3102 # Run the user's shell. If none defined, run Bourne.
3103 # We resume execution when the shell terminates.
3104 &system( $ENV{SHELL} || "/bin/sh" );
3108 =head4 C<$sh I<command>> - Force execution of a command in a shell
3110 Like the above, but the command is passed to the shell. Again, we use
3111 C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
3115 # $sh command - start a shell and run a command in it.
3116 $cmd =~ /^$sh\s*([\x00-\xff]*)/ && do {
3118 # XXX: using csh or tcsh destroys sigint retvals!
3119 #&system($1); # use this instead
3121 # use the user's shell, or Bourne if none defined.
3122 &system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3126 =head4 C<H> - display commands in history
3128 Prints the contents of C<@hist> (if any).
3132 $cmd =~ /^H\b\s*\*/ && do {
3133 @hist = @truehist = ();
3134 print $OUT "History cleansed\n";
3138 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
3140 # Anything other than negative numbers is ignored by
3141 # the (incorrect) pattern, so this test does nothing.
3142 $end = $2 ? ( $#hist - $2 ) : 0;
3144 # Set to the minimum if less than zero.
3145 $hist = 0 if $hist < 0;
3147 # Start at the end of the array.
3148 # Stay in while we're still above the ending value.
3149 # Tick back by one each time around the loop.
3150 for ( $i = $#hist ; $i > $end ; $i-- ) {
3152 # Print the command unless it has no arguments.
3153 print $OUT "$i: ", $hist[$i], "\n"
3154 unless $hist[$i] =~ /^.?$/;
3159 =head4 C<man, doc, perldoc> - look up documentation
3161 Just calls C<runman()> to print the appropriate document.
3165 # man, perldoc, doc - show manual pages.
3166 $cmd =~ /^(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?$/ && do {
3173 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3174 the bottom of the loop.
3178 # p - print (no args): print $_.
3179 $cmd =~ s/^p$/print {\$DB::OUT} \$_/;
3181 # p - print the given expression.
3182 $cmd =~ s/^p\b/print {\$DB::OUT} /;
3184 =head4 C<=> - define command alias
3186 Manipulates C<%alias> to add or list command aliases.
3190 # = - set up a command alias.
3191 $cmd =~ s/^=\s*// && do {
3193 if ( length $cmd == 0 ) {
3195 # No args, get current aliases.
3196 @keys = sort keys %alias;
3198 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3200 # Creating a new alias. $k is alias name, $v is
3203 # can't use $_ or kill //g state
3204 for my $x ( $k, $v ) {
3206 # Escape "alarm" characters.
3210 # Substitute key for value, using alarm chars
3211 # as separators (which is why we escaped them in
3213 $alias{$k} = "s\a$k\a$v\a";
3215 # Turn off standard warn and die behavior.
3216 local $SIG{__DIE__};
3217 local $SIG{__WARN__};
3220 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3222 # Nope. Bad alias. Say so and get out.
3223 print $OUT "Can't alias $k to $v: $@\n";
3228 # We'll only list the new one.
3230 } ## end elsif (my ($k, $v) = ($cmd...
3232 # The argument is the alias to list.
3240 # Messy metaquoting: Trim the substiution code off.
3241 # We use control-G as the delimiter because it's not
3242 # likely to appear in the alias.
3243 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3246 print $OUT "$k\t= $1\n";
3248 elsif ( defined $alias{$k} ) {
3250 # Couldn't trim it off; just print the alias code.
3251 print $OUT "$k\t$alias{$k}\n";
3256 print "No alias for $k\n";
3258 } ## end for my $k (@keys)
3262 =head4 C<source> - read commands from a file.
3264 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3269 # source - read commands from a file (or pipe!) and execute.
3270 $cmd =~ /^source\s+(.*\S)/ && do {
3271 if ( open my $fh, $1 ) {
3273 # Opened OK; stick it in the list of file handles.
3279 &warn("Can't execute `$1': $!\n");
3284 =head4 C<save> - send current history to a file
3286 Takes the complete history, (not the shrunken version you see with C<H>),
3287 and saves it to the given filename, so it can be replayed using C<source>.
3289 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3293 # save source - write commands to a file for later use
3294 $cmd =~ /^save\s*(.*)$/ && do {
3295 my $file = $1 || '.perl5dbrc'; # default?
3296 if ( open my $fh, "> $file" ) {
3298 # chomp to remove extraneous newlines from source'd files
3299 chomp( my @truelist =
3300 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3302 print $fh join( "\n", @truelist );
3303 print "commands saved in $file\n";
3306 &warn("Can't save debugger commands in '$1': $!\n");
3311 =head4 C<R> - restart
3313 Restart the debugger session.
3315 =head4 C<rerun> - rerun the current session
3317 Return to any given position in the B<true>-history list
3321 # R - restart execution.
3322 # rerun - controlled restart execution.
3323 $cmd =~ /^(R|rerun\s*(.*))$/ && do {
3324 my @args = ($1 eq 'R' ? restart() : rerun($2));
3326 # Close all non-system fds for a clean restart. A more
3327 # correct method would be to close all fds that were not
3328 # open when the process started, but this seems to be
3329 # hard. See "debugger 'R'estart and open database
3330 # connections" on p5p.
3332 my $max_fd = 1024; # default if POSIX can't be loaded
3333 if (eval { require POSIX }) {
3334 $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX());
3337 if (defined $max_fd) {
3338 foreach ($^F+1 .. $max_fd-1) {
3339 next unless open FD_TO_CLOSE, "<&=$_";
3344 # And run Perl again. We use exec() to keep the
3345 # PID stable (and that way $ini_pids is still valid).
3346 exec(@args) || print $OUT "exec failed: $!\n";
3351 =head4 C<|, ||> - pipe output through the pager.
3353 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3354 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3355 pipe to the pager (restoring the output filehandles if this fails). If this
3356 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3357 set C<$signal>, sending us back into the debugger.
3359 We then trim off the pipe symbols and C<redo> the command loop at the
3360 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3365 # || - run command in the pager, with output to DB::OUT.
3366 $cmd =~ /^\|\|?\s*[^|]/ && do {
3367 if ( $pager =~ /^\|/ ) {
3369 # Default pager is into a pipe. Redirect I/O.
3370 open( SAVEOUT, ">&STDOUT" )
3371 || &warn("Can't save STDOUT");
3372 open( STDOUT, ">&OUT" )
3373 || &warn("Can't redirect STDOUT");
3374 } ## end if ($pager =~ /^\|/)
3377 # Not into a pipe. STDOUT is safe.
3378 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3381 # Fix up environment to record we have less if so.
3384 unless ( $piped = open( OUT, $pager ) ) {
3386 # Couldn't open pipe to pager.
3387 &warn("Can't pipe output to `$pager'");
3388 if ( $pager =~ /^\|/ ) {
3390 # Redirect I/O back again.
3391 open( OUT, ">&STDOUT" ) # XXX: lost message
3392 || &warn("Can't restore DB::OUT");
3393 open( STDOUT, ">&SAVEOUT" )
3394 || &warn("Can't restore STDOUT");
3396 } ## end if ($pager =~ /^\|/)
3399 # Redirect I/O. STDOUT already safe.
3400 open( OUT, ">&STDOUT" ) # XXX: lost message
3401 || &warn("Can't restore DB::OUT");
3404 } ## end unless ($piped = open(OUT,...
3406 # Set up broken-pipe handler if necessary.
3407 $SIG{PIPE} = \&DB::catch
3409 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
3411 # Save current filehandle, unbuffer out, and put it back.
3412 $selected = select(OUT);
3415 # Don't put it back if pager was a pipe.
3416 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
3418 # Trim off the pipe symbols and run the command now.
3419 $cmd =~ s/^\|+\s*//;
3423 =head3 END OF COMMAND PARSING
3425 Anything left in C<$cmd> at this point is a Perl expression that we want to
3426 evaluate. We'll always evaluate in the user's context, and fully qualify
3427 any variables we might want to address in the C<DB> package.
3431 # t - turn trace on.
3432 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3434 # s - single-step. Remember the last command was 's'.
3435 $cmd =~ s/^s\s/\$DB::single = 1;\n/ && do { $laststep = 's' };
3437 # n - single-step, but not into subs. Remember last command
3439 $cmd =~ s/^n\s/\$DB::single = 2;\n/ && do { $laststep = 'n' };
3443 # Make sure the flag that says "the debugger's running" is
3444 # still on, to make sure we get control again.
3445 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3447 # Run *our* eval that executes in the caller's context.
3450 # Turn off the one-time-dump stuff now.
3452 $onetimeDump = undef;
3453 $onetimedumpDepth = undef;
3455 elsif ( $term_pid == $$ ) {
3456 eval { # May run under miniperl, when not available...
3461 # XXX If this is the master pid, print a newline.
3464 } ## end while (($term || &setterm...
3466 =head3 POST-COMMAND PROCESSING
3468 After each command, we check to see if the command output was piped anywhere.
3469 If so, we go through the necessary code to unhook the pipe and go back to
3470 our standard filehandles for input and output.
3476 # At the end of every command:
3479 # Unhook the pipe mechanism now.
3480 if ( $pager =~ /^\|/ ) {
3482 # No error from the child.
3485 # we cannot warn here: the handle is missing --tchrist
3486 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
3488 # most of the $? crud was coping with broken cshisms
3489 # $? is explicitly set to 0, so this never runs.
3491 print SAVEOUT "Pager `$pager' failed: ";
3493 print SAVEOUT "shell returned -1\n";
3496 print SAVEOUT ( $? & 127 )
3497 ? " (SIG#" . ( $? & 127 ) . ")"
3498 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3501 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3505 # Reopen filehandle for our output (if we can) and
3506 # restore STDOUT (if we can).
3507 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3508 open( STDOUT, ">&SAVEOUT" )
3509 || &warn("Can't restore STDOUT");
3511 # Turn off pipe exception handler if necessary.
3512 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
3514 # Will stop ignoring SIGPIPE if done like nohup(1)
3515 # does SIGINT but Perl doesn't give us a choice.
3516 } ## end if ($pager =~ /^\|/)
3519 # Non-piped "pager". Just restore STDOUT.
3520 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3523 # Close filehandle pager was using, restore the normal one
3526 select($selected), $selected = "" unless $selected eq "";
3530 } ## end if ($piped)
3533 =head3 COMMAND LOOP TERMINATION
3535 When commands have finished executing, we come here. If the user closed the
3536 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3537 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3538 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3539 The interpreter will then execute the next line and then return control to us
3544 # No more commands? Quit.
3545 $fall_off_end = 1 unless defined $cmd; # Emulate `q' on EOF
3547 # Evaluate post-prompt commands.
3548 foreach $evalarg (@$post) {
3551 } # if ($single || $signal)
3553 # Put the user's globals back where you found them.
3554 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3558 # The following code may be executed now:
3563 C<sub> is called whenever a subroutine call happens in the program being
3564 debugged. The variable C<$DB::sub> contains the name of the subroutine
3567 The core function of this subroutine is to actually call the sub in the proper
3568 context, capturing its output. This of course causes C<DB::DB> to get called
3569 again, repeating until the subroutine ends and returns control to C<DB::sub>
3570 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3571 return value, and returns its captured copy of the return value as its own
3572 return value. The value then feeds back into the program being debugged as if
3573 C<DB::sub> hadn't been there at all.
3575 C<sub> does all the work of printing the subroutine entry and exit messages
3576 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3577 and also prints the return value if needed (for the C<r> command and if
3578 the 16 bit is set in C<$frame>).
3580 It also tracks the subroutine call depth by saving the current setting of
3581 C<$single> in the C<@stack> package global; if this exceeds the value in
3582 C<$deep>, C<sub> automatically turns on printing of the current depth by
3583 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
3584 of stop/don't stop on entry to subs set as it currently is set.
3586 =head3 C<caller()> support
3588 If C<caller()> is called from the package C<DB>, it provides some
3589 additional data, in the following order:
3595 The package name the sub was in
3597 =item * C<$filename>
3599 The filename it was defined in
3603 The line number it was defined on
3605 =item * C<$subroutine>
3607 The subroutine name; C<(eval)> if an C<eval>().
3611 1 if it has arguments, 0 if not
3613 =item * C<$wantarray>
3615 1 if array context, 0 if scalar context
3617 =item * C<$evaltext>
3619 The C<eval>() text, if any (undefined for C<eval BLOCK>)
3621 =item * C<$is_require>
3623 frame was created by a C<use> or C<require> statement
3627 pragma information; subject to change between versions
3631 pragma information; subject to change between versions
3633 =item * C<@DB::args>
3635 arguments with which the subroutine was invoked
3643 # lock ourselves under threads
3646 # Whether or not the autoloader was running, a scalar to put the
3647 # sub's return value in (if needed), and an array to put the sub's
3648 # return value in (if needed).
3649 my ( $al, $ret, @ret ) = "";
3650 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
3651 print "creating new thread\n";
3654 # If the last ten characters are '::AUTOLOAD', note we've traced
3655 # into AUTOLOAD for $sub.
3656 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3657 $al = " for $$sub" if defined $$sub;
3660 # We stack the stack pointer and then increment it to protect us
3661 # from a situation that might unwind a whole bunch of call frames
3662 # at once. Localizing the stack pointer means that it will automatically
3663 # unwind the same amount when multiple stack frames are unwound.
3664 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3667 $#stack = $stack_depth;
3669 # Save current single-step setting.
3670 $stack[-1] = $single;
3672 # Turn off all flags except single-stepping.
3675 # If we've gotten really deeply recursed, turn on the flag that will
3676 # make us stop with the 'deep recursion' message.
3677 $single |= 4 if $stack_depth == $deep;
3679 # If frame messages are on ...
3681 $frame & 4 # Extended frame entry message
3683 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3685 # Why -1? But it works! :-(
3686 # Because print_trace will call add 1 to it and then call
3687 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3689 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3691 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3693 # standard frame entry message
3697 # Determine the sub's return type,and capture approppriately.
3700 # Called in array context. call sub and capture output.
3701 # DB::DB will recursively get control again if appropriate; we'll come
3702 # back here when the sub is finished.
3705 # Pop the single-step value back off the stack.
3706 $single |= $stack[ $stack_depth-- ];
3708 # Check for exit trace messages...
3710 $frame & 4 # Extended exit message
3712 print_lineinfo( ' ' x $stack_depth, "out " ),
3713 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3715 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3717 # Standard exit message
3721 # Print the return info if we need to.
3722 if ( $doret eq $stack_depth or $frame & 16 ) {
3724 # Turn off output record separator.
3726 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3728 # Indent if we're printing because of $frame tracing.
3729 print $fh ' ' x $stack_depth if $frame & 16;
3731 # Print the return value.
3732 print $fh "list context return from $sub:\n";
3733 dumpit( $fh, \@ret );
3735 # And don't print it again.
3737 } ## end if ($doret eq $stack_depth...
3738 # And we have to return the return value now.
3740 } ## end if (wantarray)
3744 if ( defined wantarray ) {
3746 # Save the value if it's wanted at all.
3751 # Void return, explicitly.
3756 # Pop the single-step value off the stack.
3757 $single |= $stack[ $stack_depth-- ];
3759 # If we're doing exit messages...
3761 $frame & 4 # Extended messsages
3763 print_lineinfo( ' ' x $stack_depth, "out " ),
3764 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3766 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3772 # If we are supposed to show the return value... same as before.
3773 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
3775 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3776 print $fh ( ' ' x $stack_depth ) if $frame & 16;
3779 ? "scalar context return from $sub: "
3780 : "void context return from $sub\n"
3782 dumpit( $fh, $ret ) if defined wantarray;
3784 } ## end if ($doret eq $stack_depth...
3786 # Return the appropriate scalar value.
3788 } ## end else [ if (wantarray)
3793 # lock ourselves under threads
3796 # Whether or not the autoloader was running, a scalar to put the
3797 # sub's return value in (if needed), and an array to put the sub's
3798 # return value in (if needed).
3799 my ( $al, $ret, @ret ) = "";
3800 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
3801 print "creating new thread\n";
3804 # If the last ten characters are C'::AUTOLOAD', note we've traced
3805 # into AUTOLOAD for $sub.
3806 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3810 # We stack the stack pointer and then increment it to protect us
3811 # from a situation that might unwind a whole bunch of call frames
3812 # at once. Localizing the stack pointer means that it will automatically
3813 # unwind the same amount when multiple stack frames are unwound.
3814 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3817 $#stack = $stack_depth;
3819 # Save current single-step setting.
3820 $stack[-1] = $single;
3822 # Turn off all flags except single-stepping.
3825 # If we've gotten really deeply recursed, turn on the flag that will
3826 # make us stop with the 'deep recursion' message.
3827 $single |= 4 if $stack_depth == $deep;
3829 # If frame messages are on ...
3831 $frame & 4 # Extended frame entry message
3833 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3835 # Why -1? But it works! :-(
3836 # Because print_trace will call add 1 to it and then call
3837 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3839 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3841 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3843 # standard frame entry message
3847 # Pop the single-step value back off the stack.
3848 $single |= $stack[ $stack_depth-- ];
3850 # call the original lvalue sub.
3854 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
3856 In Perl 5.8.0, there was a major realignment of the commands and what they did,
3857 Most of the changes were to systematize the command structure and to eliminate
3858 commands that threw away user input without checking.
3860 The following sections describe the code added to make it easy to support
3861 multiple command sets with conflicting command names. This section is a start
3862 at unifying all command processing to make it simpler to develop commands.
3864 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
3865 number, and C<$dbline> (the current line) as arguments.
3867 Support functions in this section which have multiple modes of failure C<die>
3868 on error; the rest simply return a false value.
3870 The user-interface functions (all of the C<cmd_*> functions) just output
3875 The C<%set> hash defines the mapping from command letter to subroutine
3878 C<%set> is a two-level hash, indexed by set name and then by command name.
3879 Note that trying to set the CommandSet to C<foobar> simply results in the
3880 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
3889 'A' => 'pre580_null',
3891 'B' => 'pre580_null',
3892 'd' => 'pre580_null',
3895 'M' => 'pre580_null',
3897 'o' => 'pre580_null',
3903 '<' => 'pre590_prepost',
3904 '<<' => 'pre590_prepost',
3905 '>' => 'pre590_prepost',
3906 '>>' => 'pre590_prepost',
3907 '{' => 'pre590_prepost',
3908 '{{' => 'pre590_prepost',
3912 =head2 C<cmd_wrapper()> (API)
3914 C<cmd_wrapper()> allows the debugger to switch command sets
3915 depending on the value of the C<CommandSet> option.
3917 It tries to look up the command in the C<%set> package-level I<lexical>
3918 (which means external entities can't fiddle with it) and create the name of
3919 the sub to call based on the value found in the hash (if it's there). I<All>
3920 of the commands to be handled in a set have to be added to C<%set>; if they
3921 aren't found, the 5.8.0 equivalent is called (if there is one).
3923 This code uses symbolic references.
3930 my $dblineno = shift;
3932 # Assemble the command subroutine's name by looking up the
3933 # command set and command name in %set. If we can't find it,
3934 # default to the older version of the command.
3936 . ( $set{$CommandSet}{$cmd}
3937 || ( $cmd =~ /^[<>{]+/o ? 'prepost' : $cmd ) );
3939 # Call the command subroutine, call it by name.
3940 return &$call( $cmd, $line, $dblineno );
3941 } ## end sub cmd_wrapper
3943 =head3 C<cmd_a> (command)
3945 The C<a> command handles pre-execution actions. These are associated with a
3946 particular line, so they're stored in C<%dbline>. We default to the current
3947 line if none is specified.
3953 my $line = shift || ''; # [.|line] expr
3956 # If it's dot (here), or not all digits, use the current line.
3957 $line =~ s/^(\.|(?:[^\d]))/$dbline/;
3959 # Should be a line number followed by an expression.
3960 if ( $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
3961 my ( $lineno, $expr ) = ( $1, $2 );
3963 # If we have an expression ...
3964 if ( length $expr ) {
3966 # ... but the line isn't breakable, complain.
3967 if ( $dbline[$lineno] == 0 ) {
3969 "Line $lineno($dbline[$lineno]) does not have an action?\n";
3973 # It's executable. Record that the line has an action.
3974 $had_breakpoints{$filename} |= 2;
3976 # Remove any action, temp breakpoint, etc.
3977 $dbline{$lineno} =~ s/\0[^\0]*//;
3979 # Add the action to the line.
3980 $dbline{$lineno} .= "\0" . action($expr);
3982 } ## end if (length $expr)
3983 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
3988 "Adding an action requires an optional lineno and an expression\n"
3993 =head3 C<cmd_A> (command)
3995 Delete actions. Similar to above, except the delete code is in a separate
3996 subroutine, C<delete_action>.
4002 my $line = shift || '';
4006 $line =~ s/^\./$dbline/;
4008 # Call delete_action with a null param to delete them all.
4009 # The '1' forces the eval to be true. It'll be false only
4010 # if delete_action blows up for some reason, in which case
4011 # we print $@ and get out.
4012 if ( $line eq '*' ) {
4013 eval { &delete_action(); 1 } or print $OUT $@ and return;
4016 # There's a real line number. Pass it to delete_action.
4017 # Error trapping is as above.
4018 elsif ( $line =~ /^(\S.*)/ ) {
4019 eval { &delete_action($1); 1 } or print $OUT $@ and return;
4022 # Swing and a miss. Bad syntax.
4025 "Deleting an action requires a line number, or '*' for all\n" ; # hint
4029 =head3 C<delete_action> (API)
4031 C<delete_action> accepts either a line number or C<undef>. If a line number
4032 is specified, we check for the line being executable (if it's not, it
4033 couldn't have had an action). If it is, we just take the action off (this
4034 will get any kind of an action, including breakpoints).
4040 if ( defined($i) ) {
4043 die "Line $i has no action .\n" if $dbline[$i] == 0;
4045 # Nuke whatever's there.
4046 $dbline{$i} =~ s/\0[^\0]*//; # \^a
4047 delete $dbline{$i} if $dbline{$i} eq '';
4050 print $OUT "Deleting all actions...\n";
4051 for my $file ( keys %had_breakpoints ) {
4052 local *dbline = $main::{ '_<' . $file };
4055 for ( $i = 1 ; $i <= $max ; $i++ ) {
4056 if ( defined $dbline{$i} ) {
4057 $dbline{$i} =~ s/\0[^\0]*//;
4058 delete $dbline{$i} if $dbline{$i} eq '';
4060 unless ( $had_breakpoints{$file} &= ~2 ) {
4061 delete $had_breakpoints{$file};
4063 } ## end for ($i = 1 ; $i <= $max...
4064 } ## end for my $file (keys %had_breakpoints)
4065 } ## end else [ if (defined($i))
4066 } ## end sub delete_action
4068 =head3 C<cmd_b> (command)
4070 Set breakpoints. Since breakpoints can be set in so many places, in so many
4071 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4072 we try to parse the command type, and then shuttle it off to an appropriate
4073 subroutine to actually do the work of setting the breakpoint in the right
4080 my $line = shift; # [.|line] [cond]
4083 # Make . the current line number if it's there..
4084 $line =~ s/^\./$dbline/;
4086 # No line number, no condition. Simple break on current line.
4087 if ( $line =~ /^\s*$/ ) {
4088 &cmd_b_line( $dbline, 1 );
4091 # Break on load for a file.
4092 elsif ( $line =~ /^load\b\s*(.*)/ ) {
4098 # b compile|postpone <some sub> [<condition>]
4099 # The interpreter actually traps this one for us; we just put the
4100 # necessary condition in the %postponed hash.
4101 elsif ( $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4103 # Capture the condition if there is one. Make it true if none.
4104 my $cond = length $3 ? $3 : '1';
4106 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
4107 # if it was 'compile'.
4108 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
4110 # De-Perl4-ify the name - ' separators to ::.
4111 $subname =~ s/\'/::/g;
4113 # Qualify it into the current package unless it's already qualified.
4114 $subname = "${'package'}::" . $subname unless $subname =~ /::/;
4116 # Add main if it starts with ::.
4117 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4119 # Save the break type for this sub.
4120 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
4121 } ## end elsif ($line =~ ...
4123 # b <sub name> [<condition>]
4124 elsif ( $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4128 $cond = length $2 ? $2 : '1';
4129 &cmd_b_sub( $subname, $cond );
4132 # b <line> [<condition>].
4133 elsif ( $line =~ /^(\d*)\s*(.*)/ ) {
4135 # Capture the line. If none, it's the current line.
4136 $line = $1 || $dbline;
4138 # If there's no condition, make it '1'.
4139 $cond = length $2 ? $2 : '1';
4142 &cmd_b_line( $line, $cond );
4145 # Line didn't make sense.
4147 print "confused by line($line)?\n";
4151 =head3 C<break_on_load> (API)
4153 We want to break when this file is loaded. Mark this file in the
4154 C<%break_on_load> hash, and note that it has a breakpoint in
4155 C<%had_breakpoints>.
4161 $break_on_load{$file} = 1;
4162 $had_breakpoints{$file} |= 1;
4165 =head3 C<report_break_on_load> (API)
4167 Gives us an array of filenames that are set to break on load. Note that
4168 only files with break-on-load are in here, so simply showing the keys
4173 sub report_break_on_load {
4174 sort keys %break_on_load;
4177 =head3 C<cmd_b_load> (command)
4179 We take the file passed in and try to find it in C<%INC> (which maps modules
4180 to files they came from). We mark those files for break-on-load via
4181 C<break_on_load> and then report that it was done.
4189 # This is a block because that way we can use a redo inside it
4190 # even without there being any looping structure at all outside it.
4193 # Save short name and full path if found.
4195 push @files, $::INC{$file} if $::INC{$file};
4197 # Tack on .pm and do it again unless there was a '.' in the name
4199 $file .= '.pm', redo unless $file =~ /\./;
4202 # Do the real work here.
4203 break_on_load($_) for @files;
4205 # All the files that have break-on-load breakpoints.
4206 @files = report_break_on_load;
4208 # Normalize for the purposes of our printing this.
4211 print $OUT "Will stop on load of `@files'.\n";
4212 } ## end sub cmd_b_load
4214 =head3 C<$filename_error> (API package global)
4216 Several of the functions we need to implement in the API need to work both
4217 on the current file and on other files. We don't want to duplicate code, so
4218 C<$filename_error> is used to contain the name of the file that's being
4219 worked on (if it's not the current one).
4221 We can now build functions in pairs: the basic function works on the current
4222 file, and uses C<$filename_error> as part of its error message. Since this is
4223 initialized to C<"">, no filename will appear when we are working on the
4226 The second function is a wrapper which does the following:
4232 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4236 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4240 Calls the first function.
4242 The first function works on the I<current> file (i.e., the one we changed to),
4243 and prints C<$filename_error> in the error message (the name of the other file)
4244 if it needs to. When the functions return, C<*dbline> is restored to point
4245 to the actual current file (the one we're executing in) and
4246 C<$filename_error> is restored to C<"">. This restores everything to
4247 the way it was before the second function was called at all.
4249 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4256 $filename_error = '';
4258 =head3 breakable_line(from, to) (API)
4260 The subroutine decides whether or not a line in the current file is breakable.
4261 It walks through C<@dbline> within the range of lines specified, looking for
4262 the first line that is breakable.
4264 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4265 first line I<after> C<$to> that's breakable, if there is one.
4267 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4268 first line I<before> C<$to> that's breakable, if there is one.
4272 sub breakable_line {
4274 my ( $from, $to ) = @_;
4276 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4279 # If there are at least 2 arguments, we're trying to search a range.
4282 # $delta is positive for a forward search, negative for a backward one.
4283 my $delta = $from < $to ? +1 : -1;
4285 # Keep us from running off the ends of the file.
4286 my $limit = $delta > 0 ? $#dbline : 1;
4288 # Clever test. If you're a mathematician, it's obvious why this
4289 # test works. If not:
4290 # If $delta is positive (going forward), $limit will be $#dbline.
4291 # If $to is less than $limit, ($limit - $to) will be positive, times
4292 # $delta of 1 (positive), so the result is > 0 and we should use $to
4293 # as the stopping point.
4295 # If $to is greater than $limit, ($limit - $to) is negative,
4296 # times $delta of 1 (positive), so the result is < 0 and we should
4297 # use $limit ($#dbline) as the stopping point.
4299 # If $delta is negative (going backward), $limit will be 1.
4300 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4301 # (negative) so the result is > 0, and we use $to as the stopping
4304 # If $to is less than zero, ($limit - $to) will be positive,
4305 # times $delta of -1 (negative), so the result is not > 0, and
4306 # we use $limit (1) as the stopping point.
4308 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4309 # (negative), still giving zero; the result is not > 0, and
4310 # we use $limit (1) as the stopping point.
4312 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4313 # (negative), giving a positive (>0) value, so we'll set $limit to
4316 $limit = $to if ( $limit - $to ) * $delta > 0;
4318 # The real search loop.
4319 # $i starts at $from (the point we want to start searching from).
4320 # We move through @dbline in the appropriate direction (determined
4321 # by $delta: either -1 (back) or +1 (ahead).
4322 # We stay in as long as we haven't hit an executable line
4323 # ($dbline[$i] == 0 means not executable) and we haven't reached
4324 # the limit yet (test similar to the above).
4325 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4327 } ## end if (@_ >= 2)
4329 # If $i points to a line that is executable, return that.
4330 return $i unless $dbline[$i] == 0;
4332 # Format the message and print it: no breakable lines in range.
4333 my ( $pl, $upto ) = ( '', '' );
4334 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4336 # If there's a filename in filename_error, we'll see it.
4338 die "Line$pl $from$upto$filename_error not breakable\n";
4339 } ## end sub breakable_line
4341 =head3 breakable_line_in_filename(file, from, to) (API)
4343 Like C<breakable_line>, but look in another file.
4347 sub breakable_line_in_filename {
4349 # Capture the file name.
4352 # Swap the magic line array over there temporarily.
4353 local *dbline = $main::{ '_<' . $f };
4355 # If there's an error, it's in this other file.
4356 local $filename_error = " of `$f'";
4358 # Find the breakable line.
4361 # *dbline and $filename_error get restored when this block ends.
4363 } ## end sub breakable_line_in_filename
4365 =head3 break_on_line(lineno, [condition]) (API)
4367 Adds a breakpoint with the specified condition (or 1 if no condition was
4368 specified) to the specified line. Dies if it can't.
4373 my ( $i, $cond ) = @_;
4375 # Always true if no condition supplied.
4376 $cond = 1 unless @_ >= 2;
4382 # Woops, not a breakable line. $filename_error allows us to say
4383 # if it was in a different file.
4384 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4386 # Mark this file as having breakpoints in it.
4387 $had_breakpoints{$filename} |= 1;
4389 # If there is an action or condition here already ...
4390 if ( $dbline{$i} ) {
4392 # ... swap this condition for the existing one.
4393 $dbline{$i} =~ s/^[^\0]*/$cond/;
4397 # Nothing here - just add the condition.
4398 $dbline{$i} = $cond;
4400 } ## end sub break_on_line
4402 =head3 cmd_b_line(line, [condition]) (command)
4404 Wrapper for C<break_on_line>. Prints the failure message if it
4410 eval { break_on_line(@_); 1 } or do {
4412 print $OUT $@ and return;
4414 } ## end sub cmd_b_line
4416 =head3 break_on_filename_line(file, line, [condition]) (API)
4418 Switches to the file specified and then calls C<break_on_line> to set
4423 sub break_on_filename_line {
4424 my ( $f, $i, $cond ) = @_;
4426 # Always true if condition left off.
4427 $cond = 1 unless @_ >= 3;
4429 # Switch the magical hash temporarily.
4430 local *dbline = $main::{ '_<' . $f };
4432 # Localize the variables that break_on_line uses to make its message.
4433 local $filename_error = " of `$f'";
4434 local $filename = $f;
4436 # Add the breakpoint.
4437 break_on_line( $i, $cond );
4438 } ## end sub break_on_filename_line
4440 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4442 Switch to another file, search the range of lines specified for an
4443 executable one, and put a breakpoint on the first one you find.
4447 sub break_on_filename_line_range {
4448 my ( $f, $from, $to, $cond ) = @_;
4450 # Find a breakable line if there is one.
4451 my $i = breakable_line_in_filename( $f, $from, $to );
4453 # Always true if missing.
4454 $cond = 1 unless @_ >= 3;
4456 # Add the breakpoint.
4457 break_on_filename_line( $f, $i, $cond );
4458 } ## end sub break_on_filename_line_range
4460 =head3 subroutine_filename_lines(subname, [condition]) (API)
4462 Search for a subroutine within a given file. The condition is ignored.
4463 Uses C<find_sub> to locate the desired subroutine.
4467 sub subroutine_filename_lines {
4468 my ( $subname, $cond ) = @_;
4470 # Returned value from find_sub() is fullpathname:startline-endline.
4471 # The match creates the list (fullpathname, start, end). Falling off
4472 # the end of the subroutine returns this implicitly.
4473 find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/;
4474 } ## end sub subroutine_filename_lines
4476 =head3 break_subroutine(subname) (API)
4478 Places a break on the first line possible in the specified subroutine. Uses
4479 C<subroutine_filename_lines> to find the subroutine, and
4480 C<break_on_filename_line_range> to place the break.
4484 sub break_subroutine {
4485 my $subname = shift;
4487 # Get filename, start, and end.
4488 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
4489 or die "Subroutine $subname not found.\n";
4491 # Null condition changes to '1' (always true).
4492 $cond = 1 unless @_ >= 2;
4494 # Put a break the first place possible in the range of lines
4495 # that make up this subroutine.
4496 break_on_filename_line_range( $file, $s, $e, @_ );
4497 } ## end sub break_subroutine
4499 =head3 cmd_b_sub(subname, [condition]) (command)
4501 We take the incoming subroutine name and fully-qualify it as best we can.
4505 =item 1. If it's already fully-qualified, leave it alone.
4507 =item 2. Try putting it in the current package.
4509 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
4511 =item 4. If it starts with '::', put it in 'main::'.
4515 After all this cleanup, we call C<break_subroutine> to try to set the
4521 my ( $subname, $cond ) = @_;
4523 # Add always-true condition if we have none.
4524 $cond = 1 unless @_ >= 2;
4526 # If the subname isn't a code reference, qualify it so that
4527 # break_subroutine() will work right.
4528 unless ( ref $subname eq 'CODE' ) {
4531 $subname =~ s/\'/::/g;
4534 # Put it in this package unless it's already qualified.
4535 $subname = "${'package'}::" . $subname
4536 unless $subname =~ /::/;
4538 # Requalify it into CORE::GLOBAL if qualifying it into this
4539 # package resulted in its not being defined, but only do so
4540 # if it really is in CORE::GLOBAL.
4541 $subname = "CORE::GLOBAL::$s"
4542 if not defined &$subname
4544 and defined &{"CORE::GLOBAL::$s"};
4546 # Put it in package 'main' if it has a leading ::.
4547 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4549 } ## end unless (ref $subname eq 'CODE')
4551 # Try to set the breakpoint.
4552 eval { break_subroutine( $subname, $cond ); 1 } or do {
4554 print $OUT $@ and return;
4556 } ## end sub cmd_b_sub
4558 =head3 C<cmd_B> - delete breakpoint(s) (command)
4560 The command mostly parses the command line and tries to turn the argument
4561 into a line spec. If it can't, it uses the current line. It then calls
4562 C<delete_breakpoint> to actually do the work.
4564 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
4565 thereby deleting all the breakpoints.
4572 # No line spec? Use dbline.
4573 # If there is one, use it if it's non-zero, or wipe it out if it is.
4574 my $line = ( $_[0] =~ /^\./ ) ? $dbline : shift || '';
4577 # If the line was dot, make the line the current one.
4578 $line =~ s/^\./$dbline/;
4580 # If it's * we're deleting all the breakpoints.
4581 if ( $line eq '*' ) {
4582 eval { &delete_breakpoint(); 1 } or print $OUT $@ and return;
4585 # If there is a line spec, delete the breakpoint on that line.
4586 elsif ( $line =~ /^(\S.*)/ ) {
4587 eval { &delete_breakpoint( $line || $dbline ); 1 } or do {
4589 print $OUT $@ and return;
4591 } ## end elsif ($line =~ /^(\S.*)/)
4596 "Deleting a breakpoint requires a line number, or '*' for all\n"
4601 =head3 delete_breakpoint([line]) (API)
4603 This actually does the work of deleting either a single breakpoint, or all
4606 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
4607 just drop out with a message saying so. If it is, we remove the condition
4608 part of the 'condition\0action' that says there's a breakpoint here. If,
4609 after we've done that, there's nothing left, we delete the corresponding
4610 line in C<%dbline> to signal that no action needs to be taken for this line.
4612 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
4613 which lists all currently-loaded files which have breakpoints. We then look
4614 at each line in each of these files, temporarily switching the C<%dbline>
4615 and C<@dbline> structures to point to the files in question, and do what
4616 we did in the single line case: delete the condition in C<@dbline>, and
4617 delete the key in C<%dbline> if nothing's left.
4619 We then wholesale delete C<%postponed>, C<%postponed_file>, and
4620 C<%break_on_load>, because these structures contain breakpoints for files
4621 and code that haven't been loaded yet. We can just kill these off because there
4622 are no magical debugger structures associated with them.
4626 sub delete_breakpoint {
4629 # If we got a line, delete just that one.
4630 if ( defined($i) ) {
4632 # Woops. This line wasn't breakable at all.
4633 die "Line $i not breakable.\n" if $dbline[$i] == 0;
4635 # Kill the condition, but leave any action.
4636 $dbline{$i} =~ s/^[^\0]*//;
4638 # Remove the entry entirely if there's no action left.
4639 delete $dbline{$i} if $dbline{$i} eq '';
4642 # No line; delete them all.
4644 print $OUT "Deleting all breakpoints...\n";
4646 # %had_breakpoints lists every file that had at least one
4648 for my $file ( keys %had_breakpoints ) {
4650 # Switch to the desired file temporarily.
4651 local *dbline = $main::{ '_<' . $file };
4656 # For all lines in this file ...
4657 for ( $i = 1 ; $i <= $max ; $i++ ) {
4659 # If there's a breakpoint or action on this line ...
4660 if ( defined $dbline{$i} ) {
4662 # ... remove the breakpoint.
4663 $dbline{$i} =~ s/^[^\0]+//;
4664 if ( $dbline{$i} =~ s/^\0?$// ) {
4666 # Remove the entry altogether if no action is there.
4669 } ## end if (defined $dbline{$i...
4670 } ## end for ($i = 1 ; $i <= $max...
4672 # If, after we turn off the "there were breakpoints in this file"
4673 # bit, the entry in %had_breakpoints for this file is zero,
4674 # we should remove this file from the hash.
4675 if ( not $had_breakpoints{$file} &= ~1 ) {
4676 delete $had_breakpoints{$file};
4678 } ## end for my $file (keys %had_breakpoints)
4680 # Kill off all the other breakpoints that are waiting for files that
4681 # haven't been loaded yet.
4683 undef %postponed_file;
4684 undef %break_on_load;
4685 } ## end else [ if (defined($i))
4686 } ## end sub delete_breakpoint
4688 =head3 cmd_stop (command)
4690 This is meant to be part of the new command API, but it isn't called or used
4691 anywhere else in the debugger. XXX It is probably meant for use in development
4696 sub cmd_stop { # As on ^C, but not signal-safy.
4700 =head3 C<cmd_e> - threads
4702 Display the current thread id:
4706 This could be how (when implemented) to send commands to this thread id (e cmd)
4707 or that thread id (e tid cmd).
4714 unless (exists($INC{'threads.pm'})) {
4715 print "threads not loaded($ENV{PERL5DB_THREADED})
4716 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4718 my $tid = threads->tid;
4719 print "thread id: $tid\n";
4723 =head3 C<cmd_E> - list of thread ids
4725 Display the list of available thread ids:
4729 This could be used (when implemented) to send commands to all threads (E cmd).
4736 unless (exists($INC{'threads.pm'})) {
4737 print "threads not loaded($ENV{PERL5DB_THREADED})
4738 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4740 my $tid = threads->tid;
4741 print "thread ids: ".join(', ',
4742 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
4747 =head3 C<cmd_h> - help command (command)
4749 Does the work of either
4755 Showing all the debugger help
4759 Showing help for a specific command
4768 # If we have no operand, assume null.
4769 my $line = shift || '';
4771 # 'h h'. Print the long-format help.
4772 if ( $line =~ /^h\s*/ ) {
4776 # 'h <something>'. Search for the command and print only its help.
4777 elsif ( $line =~ /^(\S.*)$/ ) {
4779 # support long commands; otherwise bogus errors
4780 # happen when you ask for h on <CR> for example
4781 my $asked = $1; # the command requested
4782 # (for proper error message)
4784 my $qasked = quotemeta($asked); # for searching; we don't
4785 # want to use it as a pattern.
4786 # XXX: finds CR but not <CR>
4788 # Search the help string for the command.
4790 $help =~ /^ # Start of a line
4792 (?:[IB]<) # Optional markup
4793 $qasked # The requested command
4798 # It's there; pull it out and print it.
4802 (?:[IB]<) # Optional markup
4803 $qasked # The command
4804 ([\s\S]*?) # Description line(s)
4805 \n) # End of last description line
4806 (?!\s) # Next line not starting with
4815 # Not found; not a debugger command.
4817 print_help("B<$asked> is not a debugger command.\n");
4819 } ## end elsif ($line =~ /^(\S.*)$/)
4821 # 'h' - print the summary help.
4823 print_help($summary);
4827 =head3 C<cmd_i> - inheritance display
4829 Display the (nested) parentage of the module or object given.
4836 eval { require Class::ISA };
4838 &warn( $@ =~ /locate/
4839 ? "Class::ISA module not found - please install\n"
4844 foreach my $isa ( split( /\s+/, $line ) ) {
4850 map { # snaffled unceremoniously from Class::ISA
4853 defined( ${"$_\::VERSION"} )
4854 ? ' ' . ${"$_\::VERSION"}
4856 } Class::ISA::self_and_super_path(ref($isa) || $isa)
4863 =head3 C<cmd_l> - list lines (command)
4865 Most of the command is taken up with transforming all the different line
4866 specification syntaxes into 'start-stop'. After that is done, the command
4867 runs a loop over C<@dbline> for the specified range of lines. It handles
4868 the printing of each line and any markers (C<==E<gt>> for current line,
4869 C<b> for break on this line, C<a> for action on this line, C<:> for this
4872 We save the last line listed in the C<$start> global for further listing
4878 my $current_line = $line;
4882 # If this is '-something', delete any spaces after the dash.
4883 $line =~ s/^-\s*$/-/;
4885 # If the line is '$something', assume this is a scalar containing a
4887 if ( $line =~ /^(\$.*)/s ) {
4889 # Set up for DB::eval() - evaluate in *user* context.
4894 # Ooops. Bad scalar.
4895 print( $OUT "Error: $@\n" ), next CMD if $@;
4897 # Good scalar. If it's a reference, find what it points to.
4899 print( $OUT "Interpreted as: $1 $s\n" );
4902 # Call self recursively to really do the command.
4904 } ## end if ($line =~ /^(\$.*)/s)
4906 # l name. Try to find a sub by that name.
4907 elsif ( $line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s ) {
4908 my $s = $subname = $1;
4911 $subname =~ s/\'/::/;
4913 # Put it in this package unless it starts with ::.
4914 $subname = $package . "::" . $subname unless $subname =~ /::/;
4916 # Put it in CORE::GLOBAL if t doesn't start with :: and
4917 # it doesn't live in this package and it lives in CORE::GLOBAL.
4918 $subname = "CORE::GLOBAL::$s"
4919 if not defined &$subname
4921 and defined &{"CORE::GLOBAL::$s"};
4923 # Put leading '::' names into 'main::'.
4924 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4926 # Get name:start-stop from find_sub, and break this up at
4928 @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
4930 # Pull off start-stop.
4931 $subrange = pop @pieces;
4933 # If the name contained colons, the split broke it up.
4934 # Put it back together.
4935 $file = join( ':', @pieces );
4937 # If we're not in that file, switch over to it.
4938 if ( $file ne $filename ) {
4939 print $OUT "Switching to file '$file'.\n"
4940 unless $slave_editor;
4942 # Switch debugger's magic structures.
4943 *dbline = $main::{ '_<' . $file };
4946 } ## end if ($file ne $filename)
4948 # Subrange is 'start-stop'. If this is less than a window full,
4949 # swap it to 'start+', which will list a window from the start point.
4951 if ( eval($subrange) < -$window ) {
4952 $subrange =~ s/-.*/+/;
4955 # Call self recursively to list the range.
4957 &cmd_l( 'l', $subrange );
4958 } ## end if ($subrange)
4962 print $OUT "Subroutine $subname not found.\n";
4964 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s)
4967 elsif ( $line =~ /^\s*$/ ) {
4969 # Compute new range to list.
4970 $incr = $window - 1;
4971 $line = $start . '-' . ( $start + $incr );
4974 &cmd_l( 'l', $line );
4977 # l [start]+number_of_lines
4978 elsif ( $line =~ /^(\d*)\+(\d*)$/ ) {
4980 # Don't reset start for 'l +nnn'.
4983 # Increment for list. Use window size if not specified.
4984 # (Allows 'l +' to work.)
4986 $incr = $window - 1 unless $incr;
4988 # Create a line range we'll understand, and recurse to do it.
4989 $line = $start . '-' . ( $start + $incr );
4990 &cmd_l( 'l', $line );
4991 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/)
4993 # l start-stop or l start,stop
4994 elsif ( $line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/ ) {
4996 # Determine end point; use end of file if not specified.
4997 $end = ( !defined $2 ) ? $max : ( $4 ? $4 : $2 );
4999 # Go on to the end, and then stop.
5000 $end = $max if $end > $max;
5002 # Determine start line.
5004 $i = $line if $i eq '.';
5008 # If we're running under a slave editor, force it to show the lines.
5009 if ($slave_editor) {
5010 print $OUT "\032\032$filename:$i:0\n";
5014 # We're doing it ourselves. We want to show the line and special
5016 # - the current line in execution
5017 # - whether a line is breakable or not
5018 # - whether a line has a break or not
5019 # - whether a line has an action or not
5021 for ( ; $i <= $end ; $i++ ) {
5023 # Check for breakpoints and actions.
5024 my ( $stop, $action );
5025 ( $stop, $action ) = split( /\0/, $dbline{$i} )
5028 # ==> if this is the current line in execution,
5029 # : if it's breakable.
5031 ( $i == $current_line and $filename eq $filename_ini )
5033 : ( $dbline[$i] + 0 ? ':' : ' ' );
5035 # Add break and action indicators.
5036 $arrow .= 'b' if $stop;
5037 $arrow .= 'a' if $action;
5040 print $OUT "$i$arrow\t", $dbline[$i];
5042 # Move on to the next line. Drop out on an interrupt.
5043 $i++, last if $signal;
5044 } ## end for (; $i <= $end ; $i++)
5046 # Line the prompt up; print a newline if the last line listed
5047 # didn't have a newline.
5048 print $OUT "\n" unless $dbline[ $i - 1 ] =~ /\n$/;
5049 } ## end else [ if ($slave_editor)
5051 # Save the point we last listed to in case another relative 'l'
5052 # command is desired. Don't let it run off the end.
5054 $start = $max if $start > $max;
5055 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/)
5058 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5060 To list breakpoints, the command has to look determine where all of them are
5061 first. It starts a C<%had_breakpoints>, which tells us what all files have
5062 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5063 magic source and breakpoint data structures) to the file, and then look
5064 through C<%dbline> for lines with breakpoints and/or actions, listing them
5065 out. We look through C<%postponed> not-yet-compiled subroutines that have
5066 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5067 that have breakpoints.
5069 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5076 # If no argument, list everything. Pre-5.8.0 version always lists
5078 my $arg = shift || 'abw';
5079 $arg = 'abw' unless $CommandSet eq '580'; # sigh...
5081 # See what is wanted.
5082 my $action_wanted = ( $arg =~ /a/ ) ? 1 : 0;
5083 my $break_wanted = ( $arg =~ /b/ ) ? 1 : 0;
5084 my $watch_wanted = ( $arg =~ /w/ ) ? 1 : 0;
5086 # Breaks and actions are found together, so we look in the same place
5088 if ( $break_wanted or $action_wanted ) {
5090 # Look in all the files with breakpoints...
5091 for my $file ( keys %had_breakpoints ) {
5093 # Temporary switch to this file.
5094 local *dbline = $main::{ '_<' . $file };
5096 # Set up to look through the whole file.
5098 my $was; # Flag: did we print something
5101 # For each line in the file ...
5102 for ( $i = 1 ; $i <= $max ; $i++ ) {
5104 # We've got something on this line.
5105 if ( defined $dbline{$i} ) {
5107 # Print the header if we haven't.
5108 print $OUT "$file:\n" unless $was++;
5111 print $OUT " $i:\t", $dbline[$i];
5113 # Pull out the condition and the action.
5114 ( $stop, $action ) = split( /\0/, $dbline{$i} );
5116 # Print the break if there is one and it's wanted.
5117 print $OUT " break if (", $stop, ")\n"
5121 # Print the action if there is one and it's wanted.
5122 print $OUT " action: ", $action, "\n"
5126 # Quit if the user hit interrupt.
5128 } ## end if (defined $dbline{$i...
5129 } ## end for ($i = 1 ; $i <= $max...
5130 } ## end for my $file (keys %had_breakpoints)
5131 } ## end if ($break_wanted or $action_wanted)
5133 # Look for breaks in not-yet-compiled subs:
5134 if ( %postponed and $break_wanted ) {
5135 print $OUT "Postponed breakpoints in subroutines:\n";
5137 for $subname ( keys %postponed ) {
5138 print $OUT " $subname\t$postponed{$subname}\n";
5141 } ## end if (%postponed and $break_wanted)
5143 # Find files that have not-yet-loaded breaks:
5144 my @have = map { # Combined keys
5145 keys %{ $postponed_file{$_} }
5146 } keys %postponed_file;
5148 # If there are any, list them.
5149 if ( @have and ( $break_wanted or $action_wanted ) ) {
5150 print $OUT "Postponed breakpoints in files:\n";
5151 my ( $file, $line );
5153 for $file ( keys %postponed_file ) {
5154 my $db = $postponed_file{$file};
5155 print $OUT " $file:\n";
5156 for $line ( sort { $a <=> $b } keys %$db ) {
5157 print $OUT " $line:\n";
5158 my ( $stop, $action ) = split( /\0/, $$db{$line} );
5159 print $OUT " break if (", $stop, ")\n"
5162 print $OUT " action: ", $action, "\n"
5166 } ## end for $line (sort { $a <=>...
5168 } ## end for $file (keys %postponed_file)
5169 } ## end if (@have and ($break_wanted...
5170 if ( %break_on_load and $break_wanted ) {
5171 print $OUT "Breakpoints on load:\n";
5173 for $file ( keys %break_on_load ) {
5174 print $OUT " $file\n";
5177 } ## end if (%break_on_load and...
5178 if ($watch_wanted) {
5180 print $OUT "Watch-expressions:\n" if @to_watch;
5181 for my $expr (@to_watch) {
5182 print $OUT " $expr\n";
5185 } ## end if ($trace & 2)
5186 } ## end if ($watch_wanted)
5189 =head3 C<cmd_M> - list modules (command)
5191 Just call C<list_modules>.
5199 =head3 C<cmd_o> - options (command)
5201 If this is just C<o> by itself, we list the current settings via
5202 C<dump_option>. If there's a nonblank value following it, we pass that on to
5203 C<parse_options> for processing.
5209 my $opt = shift || ''; # opt[=val]
5211 # Nonblank. Try to parse and process.
5212 if ( $opt =~ /^(\S.*)/ ) {
5216 # Blank. List the current option settings.
5224 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5226 Advises the user that the O command has been renamed.
5231 print $OUT "The old O command is now the o command.\n"; # hint
5232 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5233 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5236 =head3 C<cmd_v> - view window (command)
5238 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5239 move back a few lines to list the selected line in context. Uses C<cmd_l>
5240 to do the actual listing after figuring out the range of line to request.
5248 # Extract the line to list around. (Astute readers will have noted that
5249 # this pattern will match whether or not a numeric line is specified,
5250 # which means that we'll always enter this loop (though a non-numeric
5251 # argument results in no action at all)).
5252 if ( $line =~ /^(\d*)$/ ) {
5254 # Total number of lines to list (a windowful).
5255 $incr = $window - 1;
5257 # Set the start to the argument given (if there was one).
5260 # Back up by the context amount.
5263 # Put together a linespec that cmd_l will like.
5264 $line = $start . '-' . ( $start + $incr );
5267 &cmd_l( 'l', $line );
5268 } ## end if ($line =~ /^(\d*)$/)
5271 =head3 C<cmd_w> - add a watch expression (command)
5273 The 5.8 version of this command adds a watch expression if one is specified;
5274 it does nothing if entered with no operands.
5276 We extract the expression, save it, evaluate it in the user's context, and
5277 save the value. We'll re-evaluate it each time the debugger passes a line,
5278 and will stop (see the code at the top of the command loop) if the value
5279 of any of the expressions changes.
5286 # Null expression if no arguments.
5287 my $expr = shift || '';
5289 # If expression is not null ...
5290 if ( $expr =~ /^(\S.*)/ ) {
5293 push @to_watch, $expr;
5295 # Parameterize DB::eval and call it to get the expression's value
5296 # in the user's context. This version can handle expressions which
5297 # return a list value.
5299 my ($val) = join( ' ', &eval );
5300 $val = ( defined $val ) ? "'$val'" : 'undef';
5302 # Save the current value of the expression.
5303 push @old_watch, $val;
5305 # We are now watching expressions.
5307 } ## end if ($expr =~ /^(\S.*)/)
5309 # You have to give one to get one.
5311 print $OUT "Adding a watch-expression requires an expression\n"; # hint
5315 =head3 C<cmd_W> - delete watch expressions (command)
5317 This command accepts either a watch expression to be removed from the list
5318 of watch expressions, or C<*> to delete them all.
5320 If C<*> is specified, we simply empty the watch expression list and the
5321 watch expression value list. We also turn off the bit that says we've got
5324 If an expression (or partial expression) is specified, we pattern-match
5325 through the expressions and remove the ones that match. We also discard
5326 the corresponding values. If no watch expressions are left, we turn off
5327 the I<watching expressions> bit.
5333 my $expr = shift || '';
5336 if ( $expr eq '*' ) {
5341 print $OUT "Deleting all watch expressions ...\n";
5344 @to_watch = @old_watch = ();
5347 # Delete one of them.
5348 elsif ( $expr =~ /^(\S.*)/ ) {
5350 # Where we are in the list.
5353 # For each expression ...
5354 foreach (@to_watch) {
5355 my $val = $to_watch[$i_cnt];
5357 # Does this one match the command argument?
5358 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
5359 # Yes. Turn it off, and its value too.
5360 splice( @to_watch, $i_cnt, 1 );
5361 splice( @old_watch, $i_cnt, 1 );
5364 } ## end foreach (@to_watch)
5366 # We don't bother to turn watching off because
5367 # a) we don't want to stop calling watchfunction() it it exists
5368 # b) foreach over a null list doesn't do anything anyway
5370 } ## end elsif ($expr =~ /^(\S.*)/)
5372 # No command arguments entered.
5375 "Deleting a watch-expression requires an expression, or '*' for all\n"
5380 ### END of the API section
5382 =head1 SUPPORT ROUTINES
5384 These are general support routines that are used in a number of places
5385 throughout the debugger.
5389 save() saves the user's versions of globals that would mess us up in C<@saved>,
5390 and installs the versions we like better.
5396 # Save eval failure, command failure, extended OS error, output field
5397 # separator, input record separator, output record separator and
5398 # the warning setting.
5399 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
5401 $, = ""; # output field separator is null string
5402 $/ = "\n"; # input record separator is newline
5403 $\ = ""; # output record separator is null string
5404 $^W = 0; # warnings are off
5407 =head2 C<print_lineinfo> - show where we are now
5409 print_lineinfo prints whatever it is that it is handed; it prints it to the
5410 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
5411 us to feed line information to a slave editor without messing up the
5416 sub print_lineinfo {
5418 # Make the terminal sensible if we're not the primary debugger.
5419 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
5423 } ## end sub print_lineinfo
5425 =head2 C<postponed_sub>
5427 Handles setting postponed breakpoints in subroutines once they're compiled.
5428 For breakpoints, we use C<DB::find_sub> to locate the source file and line
5429 range for the subroutine, then mark the file as having a breakpoint,
5430 temporarily switch the C<*dbline> glob over to the source file, and then
5431 search the given range of lines to find a breakable line. If we find one,
5432 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
5436 # The following takes its argument via $evalarg to preserve current @_
5440 # Get the subroutine name.
5441 my $subname = shift;
5443 # If this is a 'break +<n> if <condition>' ...
5444 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
5446 # If there's no offset, use '+0'.
5447 my $offset = $1 || 0;
5449 # find_sub's value is 'fullpath-filename:start-stop'. It's
5450 # possible that the filename might have colons in it too.
5451 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
5454 # We got the start line. Add the offset '+<n>' from
5455 # $postponed{subname}.
5458 # Switch to the file this sub is in, temporarily.
5459 local *dbline = $main::{ '_<' . $file };
5461 # No warnings, please.
5462 local $^W = 0; # != 0 is magical below
5464 # This file's got a breakpoint in it.
5465 $had_breakpoints{$file} |= 1;
5467 # Last line in file.
5470 # Search forward until we hit a breakable line or get to
5471 # the end of the file.
5472 ++$i until $dbline[$i] != 0 or $i >= $max;
5474 # Copy the breakpoint in and delete it from %postponed.
5475 $dbline{$i} = delete $postponed{$subname};
5478 # find_sub didn't find the sub.
5481 print $OUT "Subroutine $subname not found.\n";
5484 } ## end if ($postponed{$subname...
5485 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
5487 #print $OUT "In postponed_sub for `$subname'.\n";
5488 } ## end sub postponed_sub
5492 Called after each required file is compiled, but before it is executed;
5493 also called if the name of a just-compiled subroutine is a key of
5494 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
5495 etc.) into the just-compiled code.
5497 If this is a C<require>'d file, the incoming parameter is the glob
5498 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
5500 If it's a subroutine, the incoming parameter is the subroutine name.
5506 # If there's a break, process it.
5507 if ($ImmediateStop) {
5509 # Right, we've stopped. Turn it off.
5512 # Enter the command loop when DB::DB gets called.
5516 # If this is a subroutine, let postponed_sub() deal with it.
5517 return &postponed_sub unless ref \$_[0] eq 'GLOB';
5519 # Not a subroutine. Deal with the file.
5520 local *dbline = shift;
5521 my $filename = $dbline;
5522 $filename =~ s/^_<//;
5524 $signal = 1, print $OUT "'$filename' loaded...\n"
5525 if $break_on_load{$filename};
5526 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
5528 # Do we have any breakpoints to put in this file?
5529 return unless $postponed_file{$filename};
5531 # Yes. Mark this file as having breakpoints.
5532 $had_breakpoints{$filename} |= 1;
5534 # "Cannot be done: unsufficient magic" - we can't just put the
5535 # breakpoints saved in %postponed_file into %dbline by assigning
5536 # the whole hash; we have to do it one item at a time for the
5537 # breakpoints to be set properly.
5538 #%dbline = %{$postponed_file{$filename}};
5540 # Set the breakpoints, one at a time.
5543 for $key ( keys %{ $postponed_file{$filename} } ) {
5545 # Stash the saved breakpoint into the current file's magic line array.
5546 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
5549 # This file's been compiled; discard the stored breakpoints.
5550 delete $postponed_file{$filename};
5552 } ## end sub postponed
5556 C<dumpit> is the debugger's wrapper around dumpvar.pl.
5558 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
5559 a reference to a variable (the thing to be dumped) as its input.
5561 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
5562 the currently-selected filehandle, thank you very much). The current
5563 values of the package globals C<$single> and C<$trace> are backed up in
5564 lexicals, and they are turned off (this keeps the debugger from trying
5565 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
5566 preserve its current value and it is set to zero to prevent entry/exit
5567 messages from printing, and C<$doret> is localized as well and set to -2 to
5568 prevent return values from being shown.
5570 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
5571 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
5572 installed version in C<@INC>, yours will be used instead. Possible security
5575 It then checks to see if the subroutine C<main::dumpValue> is now defined
5576 (it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
5577 localizes the globals necessary for things to be sane when C<main::dumpValue()>
5578 is called, and picks up the variable to be dumped from the parameter list.
5580 It checks the package global C<%options> to see if there's a C<dumpDepth>
5581 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
5582 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
5583 structure: -1 means dump everything.
5585 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
5588 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
5589 and we then return to the caller.
5595 # Save the current output filehandle and switch to the one
5596 # passed in as the first parameter.
5597 local ($savout) = select(shift);
5599 # Save current settings of $single and $trace, and then turn them off.
5600 my $osingle = $single;
5601 my $otrace = $trace;
5602 $single = $trace = 0;
5604 # XXX Okay, what do $frame and $doret do, again?
5608 # Load dumpvar.pl unless we've already got the sub we need from it.
5609 unless ( defined &main::dumpValue ) {
5610 do 'dumpvar.pl' or die $@;
5613 # If the load succeeded (or we already had dumpvalue()), go ahead
5615 if ( defined &main::dumpValue ) {
5620 my $maxdepth = shift || $option{dumpDepth};
5621 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
5622 &main::dumpValue( $v, $maxdepth );
5623 } ## end if (defined &main::dumpValue)
5625 # Oops, couldn't load dumpvar.pl.
5628 print $OUT "dumpvar.pl not available.\n";
5631 # Reset $single and $trace to their old values.
5635 # Restore the old filehandle.
5639 =head2 C<print_trace>
5641 C<print_trace>'s job is to print a stack trace. It does this via the
5642 C<dump_trace> routine, which actually does all the ferreting-out of the
5643 stack trace data. C<print_trace> takes care of formatting it nicely and
5644 printing it to the proper filehandle.
5652 The filehandle to print to.
5656 How many frames to skip before starting trace.
5660 How many frames to print.
5664 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
5668 The original comment below seems to be noting that the traceback may not be
5669 correct if this routine is called in a tied method.
5673 # Tied method do not create a context, so may get wrong message:
5679 # If this is going to a slave editor, but we're not the primary
5680 # debugger, reset it first.
5682 if $fh eq $LINEINFO # slave editor
5683 and $LINEINFO eq $OUT # normal output
5684 and $term_pid != $$; # not the primary
5686 # Collect the actual trace information to be formatted.
5687 # This is an array of hashes of subroutine call info.
5688 my @sub = dump_trace( $_[0] + 1, $_[1] );
5690 # Grab the "short report" flag from @_.
5691 my $short = $_[2]; # Print short report, next one for sub name
5693 # Run through the traceback info, format it, and print it.
5695 for ( $i = 0 ; $i <= $#sub ; $i++ ) {
5697 # Drop out if the user has lost interest and hit control-C.
5700 # Set the separator so arrys print nice.
5703 # Grab and stringify the arguments if they are there.
5705 defined $sub[$i]{args}
5706 ? "(@{ $sub[$i]{args} })"
5709 # Shorten them up if $maxtrace says they're too long.
5710 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
5711 if length $args > $maxtrace;
5713 # Get the file name.
5714 my $file = $sub[$i]{file};
5716 # Put in a filename header if short is off.
5717 $file = $file eq '-e' ? $file : "file `$file'" unless $short;
5719 # Get the actual sub's name, and shorten to $maxtrace's requirement.
5721 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
5723 # Short report uses trimmed file and sub names.
5725 my $sub = @_ >= 4 ? $_[3] : $s;
5726 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
5727 } ## end if ($short)
5729 # Non-short report includes full names.
5731 print $fh "$sub[$i]{context} = $s$args"
5732 . " called from $file"
5733 . " line $sub[$i]{line}\n";
5735 } ## end for ($i = 0 ; $i <= $#sub...
5736 } ## end sub print_trace
5738 =head2 dump_trace(skip[,count])
5740 Actually collect the traceback information available via C<caller()>. It does
5741 some filtering and cleanup of the data, but mostly it just collects it to
5742 make C<print_trace()>'s job easier.
5744 C<skip> defines the number of stack frames to be skipped, working backwards
5745 from the most current. C<count> determines the total number of frames to
5746 be returned; all of them (well, the first 10^9) are returned if C<count>
5749 This routine returns a list of hashes, from most-recent to least-recent
5750 stack frame. Each has the following keys and values:
5754 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
5756 =item * C<sub> - subroutine name, or C<eval> information
5758 =item * C<args> - undef, or a reference to an array of arguments
5760 =item * C<file> - the file in which this item was defined (if any)
5762 =item * C<line> - the line on which it was defined
5770 # How many levels to skip.
5773 # How many levels to show. (1e9 is a cheap way of saying "all of them";
5774 # it's unlikely that we'll have more than a billion stack frames. If you
5775 # do, you've got an awfully big machine...)
5776 my $count = shift || 1e9;
5778 # We increment skip because caller(1) is the first level *back* from
5779 # the current one. Add $skip to the count of frames so we have a
5780 # simple stop criterion, counting from $skip to $count+$skip.
5784 # These variables are used to capture output from caller();
5785 my ( $p, $file, $line, $sub, $h, $context );
5787 my ( $e, $r, @a, @sub, $args );
5789 # XXX Okay... why'd we do that?
5790 my $nothard = not $frame & 8;
5793 # Do not want to trace this.
5794 my $otrace = $trace;
5797 # Start out at the skip count.
5798 # If we haven't reached the number of frames requested, and caller() is
5799 # still returning something, stay in the loop. (If we pass the requested
5800 # number of stack frames, or we run out - caller() returns nothing - we
5802 # Up the stack frame index to go back one more level each time.
5806 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
5811 # Go through the arguments and save them for later.
5815 if ( not defined $arg ) { # undefined parameter
5819 elsif ( $nothard and tied $arg ) { # tied parameter
5822 elsif ( $nothard and $type = ref $arg ) { # reference
5823 push @a, "ref($type)";
5825 else { # can be stringified
5827 "$arg"; # Safe to stringify now - should not call f().
5829 # Backslash any single-quotes or backslashes.
5832 # Single-quote it unless it's a number or a colon-separated
5835 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
5837 # Turn high-bit characters into meta-whatever.
5838 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
5840 # Turn control characters into ^-whatever.
5841 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
5844 } ## end else [ if (not defined $arg)
5845 } ## end for $arg (@args)
5847 # If context is true, this is array (@)context.
5848 # If context is false, this is scalar ($) context.
5849 # If neither, context isn't defined. (This is apparently a 'can't
5851 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
5853 # if the sub has args ($h true), make an anonymous array of the
5855 $args = $h ? [@a] : undef;
5857 # remove trailing newline-whitespace-semicolon-end of line sequence
5858 # from the eval text, if any.
5859 $e =~ s/\n\s*\;\s*\Z// if $e;
5861 # Escape backslashed single-quotes again if necessary.
5862 $e =~ s/([\\\'])/\\$1/g if $e;
5864 # if the require flag is true, the eval text is from a require.
5866 $sub = "require '$e'";
5869 # if it's false, the eval text is really from an eval.
5870 elsif ( defined $r ) {
5874 # If the sub is '(eval)', this is a block eval, meaning we don't
5875 # know what the eval'ed text actually was.
5876 elsif ( $sub eq '(eval)' ) {
5877 $sub = "eval {...}";
5880 # Stick the collected information into @sub as an anonymous hash.
5884 context => $context,
5892 # Stop processing frames if the user hit control-C.
5894 } ## end for ($i = $skip ; $i < ...
5896 # Restore the trace value again.
5899 } ## end sub dump_trace
5903 C<action()> takes input provided as the argument to an add-action command,
5904 either pre- or post-, and makes sure it's a complete command. It doesn't do
5905 any fancy parsing; it just keeps reading input until it gets a string
5906 without a trailing backslash.
5913 while ( $action =~ s/\\$// ) {
5915 # We have a backslash on the end. Read more.
5917 } ## end while ($action =~ s/\\$//)
5919 # Return the assembled action.
5925 This routine mostly just packages up a regular expression to be used
5926 to check that the thing it's being matched against has properly-matched
5929 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
5930 speeds things up by only creating the qr//'ed expression once; if it's
5931 already defined, we don't try to define it again. A speed hack.
5937 # I hate using globals!
5938 $balanced_brace_re ||= qr{
5941 (?> [^{}] + ) # Non-parens without backtracking
5943 (??{ $balanced_brace_re }) # Group with matching parens
5947 return $_[0] !~ m/$balanced_brace_re/;
5948 } ## end sub unbalanced
5952 C<gets()> is a primitive (very primitive) routine to read continuations.
5953 It was devised for reading continuations for actions.
5954 it just reads more input with C<readline()> and returns it.
5959 &readline("cont: ");
5962 =head2 C<DB::system()> - handle calls to<system()> without messing up the debugger
5964 The C<system()> function assumes that it can just go ahead and use STDIN and
5965 STDOUT, but under the debugger, we want it to use the debugger's input and
5968 C<DB::system()> socks away the program's STDIN and STDOUT, and then substitutes
5969 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
5970 and then puts everything back again.
5976 # We save, change, then restore STDIN and STDOUT to avoid fork() since
5977 # some non-Unix systems can do system() but have problems with fork().
5978 open( SAVEIN, "<&STDIN" ) || &warn("Can't save STDIN");
5979 open( SAVEOUT, ">&STDOUT" ) || &warn("Can't save STDOUT");
5980 open( STDIN, "<&IN" ) || &warn("Can't redirect STDIN");
5981 open( STDOUT, ">&OUT" ) || &warn("Can't redirect STDOUT");
5983 # XXX: using csh or tcsh destroys sigint retvals!
5985 open( STDIN, "<&SAVEIN" ) || &warn("Can't restore STDIN");
5986 open( STDOUT, ">&SAVEOUT" ) || &warn("Can't restore STDOUT");
5990 # most of the $? crud was coping with broken cshisms
5992 &warn( "(Command exited ", ( $? >> 8 ), ")\n" );
5996 "(Command died of SIG#",
5998 ( ( $? & 128 ) ? " -- core dumped" : "" ),
6007 =head1 TTY MANAGEMENT
6009 The subs here do some of the terminal management for multiple debuggers.
6013 Top-level function called when we want to set up a new terminal for use
6016 If the C<noTTY> debugger option was set, we'll either use the terminal
6017 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
6018 to find one. If we're a forked debugger, we call C<resetterm> to try to
6019 get a whole new terminal if we can.
6021 In either case, we set up the terminal next. If the C<ReadLine> option was
6022 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6023 the appropriate attributes. We then
6029 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6032 eval { require Term::ReadLine } or die $@;
6034 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6037 my ( $i, $o ) = split $tty, /,/;
6038 $o = $i unless defined $o;
6039 open( IN, "<$i" ) or die "Cannot open TTY `$i' for read: $!";
6040 open( OUT, ">$o" ) or die "Cannot open TTY `$o' for write: $!";
6043 my $sel = select($OUT);
6048 # We don't have a TTY - try to find one via Term::Rendezvous.
6050 eval "require Term::Rendezvous;" or die;
6052 # See if we have anything to pass to Term::Rendezvous.
6053 # Use $HOME/.perldbtty$$ if not.
6054 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6056 # Rendezvous and get the filehandles.
6057 my $term_rv = new Term::Rendezvous $rv;
6059 $OUT = $term_rv->OUT;
6060 } ## end else [ if ($tty)
6061 } ## end if ($notty)
6063 # We're a daughter debugger. Try to fork off another TTY.
6064 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6068 # If we shouldn't use Term::ReadLine, don't.
6070 $term = new Term::ReadLine::Stub 'perldb', $IN, $OUT;
6073 # We're using Term::ReadLine. Get all the attributes for this terminal.
6075 $term = new Term::ReadLine 'perldb', $IN, $OUT;
6077 $rl_attribs = $term->Attribs;
6078 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6079 if defined $rl_attribs->{basic_word_break_characters}
6080 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6081 $rl_attribs->{special_prefixes} = '$@&%';
6082 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6083 $rl_attribs->{completion_function} = \&db_complete;
6084 } ## end else [ if (!$rl)
6086 # Set up the LINEINFO filehandle.
6087 $LINEINFO = $OUT unless defined $LINEINFO;
6088 $lineinfo = $console unless defined $lineinfo;
6094 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6095 $term->SetHistory(@hist);
6098 # XXX Ornaments are turned on unconditionally, which is not
6099 # always a good thing.
6100 ornaments($ornaments) if defined $ornaments;
6102 } ## end sub setterm
6105 $histfile //= option_val("HistFile", undef);
6106 return unless defined $histfile;
6107 open my $fh, "<", $histfile or return;
6118 return unless defined $histfile;
6119 eval { require File::Path } or return;
6120 eval { require File::Basename } or return;
6121 File::Path::mkpath(File::Basename::dirname($histfile));
6122 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6123 $histsize //= option_val("HistSize",100);
6124 my @copy = grep { $_ ne '?' } @hist;
6125 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6126 for ($start .. $#copy) {
6127 print $fh "$copy[$_]\n";
6129 close $fh or die "Could not write '$histfile': $!";
6132 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6134 When the process being debugged forks, or the process invokes a command
6135 via C<system()> which starts a new debugger, we need to be able to get a new
6136 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6137 fight over the terminal, and you can never quite be sure who's going to get the
6138 input you're typing.
6140 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6141 is tasked with doing all the necessary operating system mojo to get a new
6142 TTY (and probably another window) and to direct the new debugger to read and
6145 The debugger provides C<get_fork_TTY> functions which work for X Windows,
6146 OS/2, and Mac OS X. Other systems are not supported. You are encouraged
6147 to write C<get_fork_TTY> functions which work for I<your> platform
6148 and contribute them.
6150 =head3 C<xterm_get_fork_TTY>
6152 This function provides the C<get_fork_TTY> function for X windows. If a
6153 program running under the debugger forks, a new <xterm> window is opened and
6154 the subsidiary debugger is directed there.
6156 The C<open()> call is of particular note here. We have the new C<xterm>
6157 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6158 command (which prints the device name of the TTY we'll want to use for input
6159 and output to STDOUT, then C<sleep> for a very long time, routing this output
6160 to file number 3. This way we can simply read from the <XT> filehandle (which
6161 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6163 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6168 sub xterm_get_fork_TTY {
6169 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6171 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6174 # Get the output from 'tty' and clean it up a little.
6178 $pidprompt = ''; # Shown anyway in titlebar
6180 # We need $term defined or we can not switch to the newly created xterm
6181 if ($tty ne '' && !defined $term) {
6182 eval { require Term::ReadLine } or die $@;
6184 $term = new Term::ReadLine::Stub 'perldb', $IN, $OUT;
6187 $term = new Term::ReadLine 'perldb', $IN, $OUT;
6190 # There's our new TTY.
6192 } ## end sub xterm_get_fork_TTY
6194 =head3 C<os2_get_fork_TTY>
6196 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6200 # This example function resets $IN, $OUT itself
6202 sub os2_get_fork_TTY { # A simplification of the following (and works without):
6204 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6205 my %opt = ( title => "Daughter Perl debugger $pids $name",
6206 ($rl ? (read_by_key => 1) : ()) );
6207 require OS2::Process;
6208 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
6210 $pidprompt = ''; # Shown anyway in titlebar
6211 reset_IN_OUT($in, $out);
6213 return ''; # Indicate that reset_IN_OUT is called
6214 } ## end sub os2_get_fork_TTY
6216 =head3 C<macosx_get_fork_TTY>
6218 The Mac OS X version uses AppleScript to tell Terminal.app to create
6223 # Notes about Terminal.app's AppleScript support,
6224 # (aka things that might break in future OS versions).
6226 # The "do script" command doesn't return a reference to the new window
6227 # it creates, but since it appears frontmost and windows are enumerated
6228 # front to back, we can use "first window" === "window 1".
6230 # Since "do script" is implemented by supplying the argument (plus a
6231 # return character) as terminal input, there's a potential race condition
6232 # where the debugger could beat the shell to reading the command.
6233 # To prevent this, we wait for the screen to clear before proceeding.
6236 # There's no direct accessor for the tty device name, so we fiddle
6237 # with the window title options until it says what we want.
6240 # There _is_ a direct accessor for the tty device name, _and_ there's
6241 # a new possible component of the window title (the name of the settings
6242 # set). A separate version is needed.
6244 my @script_versions=
6246 ([237, <<'__LEOPARD__'],
6247 tell application "Terminal"
6248 do script "clear;exec sleep 100000"
6249 tell first tab of first window
6251 set custom title to "forked perl debugger"
6252 set title displays custom title to true
6253 repeat while (length of first paragraph of (get contents)) > 0
6261 [100, <<'__JAGUAR_TIGER__'],
6262 tell application "Terminal"
6263 do script "clear;exec sleep 100000"
6265 set title displays shell path to false
6266 set title displays window size to false
6267 set title displays file name to false
6268 set title displays device name to true
6269 set title displays custom title to true
6270 set custom title to ""
6271 copy "/dev/" & name to thetty
6272 set custom title to "forked perl debugger"
6273 repeat while (length of first paragraph of (get contents)) > 0
6283 sub macosx_get_fork_TTY
6285 my($version,$script,$pipe,$tty);
6287 return unless $version=$ENV{TERM_PROGRAM_VERSION};
6288 foreach my $entry (@script_versions) {
6289 if ($version>=$entry->[0]) {
6290 $script=$entry->[1];
6294 return unless defined($script);
6295 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script);
6296 $tty=readline($pipe);
6298 return unless defined($tty) && $tty =~ m(^/dev/);
6303 =head2 C<create_IN_OUT($flags)>
6305 Create a new pair of filehandles, pointing to a new TTY. If impossible,
6306 try to diagnose why.
6312 =item * 1 - Don't know how to create a new TTY.
6314 =item * 2 - Debugger has forked, but we can't get a new TTY.
6316 =item * 4 - standard debugger startup is happening.
6322 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
6324 # If we know how to get a new TTY, do it! $in will have
6325 # the TTY name if get_fork_TTY works.
6326 my $in = &get_fork_TTY if defined &get_fork_TTY;
6328 # It used to be that
6329 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
6331 if ( not defined $in ) {
6334 # We don't know how.
6335 print_help(<<EOP) if $why == 1;
6336 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
6340 print_help(<<EOP) if $why == 2;
6341 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
6342 This may be an asynchronous session, so the parent debugger may be active.
6345 # Note that both debuggers are fighting over the same input.
6346 print_help(<<EOP) if $why != 4;
6347 Since two debuggers fight for the same TTY, input is severely entangled.
6351 I know how to switch the output to a different window in xterms, OS/2
6352 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
6353 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
6354 B<DB::get_fork_TTY()> returning this.
6356 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
6357 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
6360 } ## end if (not defined $in)
6361 elsif ( $in ne '' ) {
6365 $console = ''; # Indicate no need to open-from-the-console
6368 } ## end sub create_IN_OUT
6372 Handles rejiggering the prompt when we've forked off a new debugger.
6374 If the new debugger happened because of a C<system()> that invoked a
6375 program under the debugger, the arrow between the old pid and the new
6376 in the prompt has I<two> dashes instead of one.
6378 We take the current list of pids and add this one to the end. If there
6379 isn't any list yet, we make one up out of the initial pid associated with
6380 the terminal and our new pid, sticking an arrow (either one-dashed or
6381 two dashed) in between them.
6383 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
6384 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
6389 sub resetterm { # We forked, so we need a different TTY
6391 # Needs to be passed to create_IN_OUT() as well.
6394 # resetterm(2): got in here because of a system() starting a debugger.
6395 # resetterm(1): just forked.
6396 my $systemed = $in > 1 ? '-' : '';
6398 # If there's already a list of pids, add this to the end.
6400 $pids =~ s/\]/$systemed->$$]/;
6403 # No pid list. Time to make one.
6405 $pids = "[$term_pid->$$]";
6408 # The prompt we're going to be using for this debugger.
6411 # We now 0wnz this terminal.
6414 # Just return if we're not supposed to try to create a new TTY.
6415 return unless $CreateTTY & $in;
6417 # Try to create a new IN/OUT pair.
6419 } ## end sub resetterm
6423 First, we handle stuff in the typeahead buffer. If there is any, we shift off
6424 the next line, print a message saying we got it, add it to the terminal
6425 history (if possible), and return it.
6427 If there's nothing in the typeahead buffer, check the command filehandle stack.
6428 If there are any filehandles there, read from the last one, and return the line
6429 if we got one. If not, we pop the filehandle off and close it, and try the
6430 next one up the stack.
6432 If we've emptied the filehandle stack, we check to see if we've got a socket
6433 open, and we read that and return it if we do. If we don't, we just call the
6434 core C<readline()> and return its value.
6440 # Localize to prevent it from being smashed in the program being debugged.
6443 # Pull a line out of the typeahead if there's stuff there.
6446 # How many lines left.
6447 my $left = @typeahead;
6449 # Get the next line.
6450 my $got = shift @typeahead;
6452 # Print a message saying we got input from the typeahead.
6454 print $OUT "auto(-$left)", shift, $got, "\n";
6456 # Add it to the terminal history (if possible).
6457 $term->AddHistory($got)
6459 and defined $term->Features->{addHistory};
6461 } ## end if (@typeahead)
6463 # We really need to read some input. Turn off entry/exit trace and
6464 # return value printing.
6468 # If there are stacked filehandles to read from ...
6471 # Read from the last one in the stack.
6472 my $line = CORE::readline( $cmdfhs[-1] );
6474 # If we got a line ...
6476 ? ( print $OUT ">> $line" and return $line ) # Echo and return
6477 : close pop @cmdfhs; # Pop and close
6478 } ## end while (@cmdfhs)
6480 # Nothing on the filehandle stack. Socket?
6481 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
6483 # Send anyting we have to send.
6484 $OUT->write( join( '', @_ ) );
6486 # Receive anything there is to receive.
6491 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
6492 # XXX Don't know. You tell me.
6493 } while length $buf and ($stuff .= $buf) !~ /\n/;
6497 } ## end if (ref $OUT and UNIVERSAL::isa...
6499 # No socket. Just read from the terminal.
6501 $term->readline(@_);
6503 } ## end sub readline
6505 =head1 OPTIONS SUPPORT ROUTINES
6507 These routines handle listing and setting option values.
6509 =head2 C<dump_option> - list the current value of an option setting
6511 This routine uses C<option_val> to look up the value for an option.
6512 It cleans up escaped single-quotes and then displays the option and
6518 my ( $opt, $val ) = @_;
6519 $val = option_val( $opt, 'N/A' );
6520 $val =~ s/([\\\'])/\\$1/g;
6521 printf $OUT "%20s = '%s'\n", $opt, $val;
6522 } ## end sub dump_option
6524 sub options2remember {
6525 foreach my $k (@RememberOnROptions) {
6526 $option{$k} = option_val( $k, 'N/A' );
6531 =head2 C<option_val> - find the current value of an option
6533 This can't just be a simple hash lookup because of the indirect way that
6534 the option values are stored. Some are retrieved by calling a subroutine,
6535 some are just variables.
6537 You must supply a default value to be used in case the option isn't set.
6542 my ( $opt, $default ) = @_;
6545 # Does this option exist, and is it a variable?
6546 # If so, retrieve the value via the value in %optionVars.
6547 if ( defined $optionVars{$opt}
6548 and defined ${ $optionVars{$opt} } )
6550 $val = ${ $optionVars{$opt} };
6553 # Does this option exist, and it's a subroutine?
6554 # If so, call the subroutine via the ref in %optionAction
6555 # and capture the value.
6556 elsif ( defined $optionAction{$opt}
6557 and defined &{ $optionAction{$opt} } )
6559 $val = &{ $optionAction{$opt} }();
6562 # If there's an action or variable for the supplied option,
6563 # but no value was set, use the default.
6564 elsif (defined $optionAction{$opt} and not defined $option{$opt}
6565 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
6570 # Otherwise, do the simple hash lookup.
6572 $val = $option{$opt};
6575 # If the value isn't defined, use the default.
6576 # Then return whatever the value is.
6577 $val = $default unless defined $val;
6579 } ## end sub option_val
6581 =head2 C<parse_options>
6583 Handles the parsing and execution of option setting/displaying commands.
6585 An option entered by itself is assumed to be I<set me to 1> (the default value)
6586 if the option is a boolean one. If not, the user is prompted to enter a valid
6587 value or to query the current value (via C<option? >).
6589 If C<option=value> is entered, we try to extract a quoted string from the
6590 value (if it is quoted). If it's not, we just use the whole value as-is.
6592 We load any modules required to service this option, and then we set it: if
6593 it just gets stuck in a variable, we do that; if there's a subroutine to
6594 handle setting the option, we call that.
6596 Finally, if we're running in interactive mode, we display the effect of the
6597 user's command back to the terminal, skipping this if we're setting things
6598 during initialization.
6606 # These options need a value. Don't allow them to be clobbered by accident.
6607 my %opt_needs_val = map { ( $_ => 1 ) } qw{
6608 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
6609 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
6615 # Clean off excess leading whitespace.
6618 # Options are always all word characters, followed by a non-word
6620 s/^(\w+)(\W?)// or print( $OUT "Invalid option `$_'\n" ), last;
6621 my ( $opt, $sep ) = ( $1, $2 );
6623 # Make sure that such an option exists.
6624 my $matches = grep( /^\Q$opt/ && ( $option = $_ ), @options )
6625 || grep( /^\Q$opt/i && ( $option = $_ ), @options );
6627 print( $OUT "Unknown option `$opt'\n" ), next unless $matches;
6628 print( $OUT "Ambiguous option `$opt'\n" ), next if $matches > 1;
6631 # '?' as separator means query, but must have whitespace after it.
6632 if ( "?" eq $sep ) {
6633 print( $OUT "Option query `$opt?' followed by non-space `$_'\n" ),
6637 #&dump_option($opt);
6638 } ## end if ("?" eq $sep)
6640 # Separator is whitespace (or just a carriage return).
6641 # They're going for a default, which we assume is 1.
6642 elsif ( $sep !~ /\S/ ) {
6644 $val = "1"; # this is an evil default; make 'em set it!
6647 # Separator is =. Trying to set a value.
6648 elsif ( $sep eq "=" ) {
6650 # If quoted, extract a quoted string.
6651 if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
6653 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
6656 # Not quoted. Use the whole thing. Warn about 'option='.
6660 print OUT qq(Option better cleared using $opt=""\n)
6662 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
6664 } ## end elsif ($sep eq "=")
6666 # "Quoted" with [], <>, or {}.
6667 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
6669 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
6670 s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
6671 or print( $OUT "Unclosed option value `$opt$sep$_'\n" ), last;
6672 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
6673 } ## end else [ if ("?" eq $sep)
6675 # Exclude non-booleans from getting set to 1 by default.
6676 if ( $opt_needs_val{$option} && $val_defaulted ) {
6677 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
6679 "Option `$opt' is non-boolean. Use `$cmd $option=VAL' to set, `$cmd $option?' to query\n";
6681 } ## end if ($opt_needs_val{$option...
6683 # Save the option value.
6684 $option{$option} = $val if defined $val;
6686 # Load any module that this option requires.
6690 require '$optionRequire{$option}';
6692 } || die # XXX: shouldn't happen
6693 if defined $optionRequire{$option}
6697 # Stick it in the proper variable if it goes in a variable.
6698 ${ $optionVars{$option} } = $val
6699 if defined $optionVars{$option}
6702 # Call the appropriate sub if it gets set via sub.
6703 &{ $optionAction{$option} }($val)
6704 if defined $optionAction{$option}
6705 && defined &{ $optionAction{$option} }
6708 # Not initialization - echo the value we set it to.
6709 dump_option($option) unless $OUT eq \*STDERR;
6710 } ## end while (length)
6711 } ## end sub parse_options
6713 =head1 RESTART SUPPORT
6715 These routines are used to store (and restore) lists of items in environment
6716 variables during a restart.
6720 Set_list packages up items to be stored in a set of environment variables
6721 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
6722 the values). Values outside the standard ASCII charset are stored by encoding
6723 then as hexadecimal values.
6728 my ( $stem, @list ) = @_;
6731 # VAR_n: how many we have. Scalar assignment gets the number of items.
6732 $ENV{"${stem}_n"} = @list;
6734 # Grab each item in the list, escape the backslashes, encode the non-ASCII
6735 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
6736 for $i ( 0 .. $#list ) {
6738 $val =~ s/\\/\\\\/g;
6739 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
6740 $ENV{"${stem}_$i"} = $val;
6741 } ## end for $i (0 .. $#list)
6742 } ## end sub set_list
6746 Reverse the set_list operation: grab VAR_n to see how many we should be getting
6747 back, and then pull VAR_0, VAR_1. etc. back out.
6754 my $n = delete $ENV{"${stem}_n"};
6756 for $i ( 0 .. $n - 1 ) {
6757 $val = delete $ENV{"${stem}_$i"};
6758 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
6762 } ## end sub get_list
6764 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
6768 The C<catch()> subroutine is the essence of fast and low-impact. We simply
6769 set an already-existing global scalar variable to a constant value. This
6770 avoids allocating any memory possibly in the middle of something that will
6771 get all confused if we do, particularly under I<unsafe signals>.
6777 return; # Put nothing on the stack - malloc/free land!
6782 C<warn> emits a warning, by joining together its arguments and printing
6783 them, with couple of fillips.
6785 If the composited message I<doesn't> end with a newline, we automatically
6786 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
6787 to be set to the filehandle to be used to output warnings; it makes no
6788 assumptions about what filehandles are available.
6793 my ($msg) = join( "", @_ );
6794 $msg .= ": $!\n" unless $msg =~ /\n$/;
6799 =head1 INITIALIZATION TTY SUPPORT
6801 =head2 C<reset_IN_OUT>
6803 This routine handles restoring the debugger's input and output filehandles
6804 after we've tried and failed to move them elsewhere. In addition, it assigns
6805 the debugger's output filehandle to $LINEINFO if it was already open there.
6810 my $switch_li = $LINEINFO eq $OUT;
6812 # If there's a term and it's able to get a new tty, try to get one.
6813 if ( $term and $term->Features->{newTTY} ) {
6814 ( $IN, $OUT ) = ( shift, shift );
6815 $term->newTTY( $IN, $OUT );
6818 # This term can't get a new tty now. Better luck later.
6820 &warn("Too late to set IN/OUT filehandles, enabled on next `R'!\n");
6823 # Set the filehndles up as they were.
6825 ( $IN, $OUT ) = ( shift, shift );
6828 # Unbuffer the output filehandle.
6829 my $o = select $OUT;
6833 # Point LINEINFO to the same output filehandle if it was there before.
6834 $LINEINFO = $OUT if $switch_li;
6835 } ## end sub reset_IN_OUT
6837 =head1 OPTION SUPPORT ROUTINES
6839 The following routines are used to process some of the more complicated
6844 Sets the input and output filehandles to the specified files or pipes.
6845 If the terminal supports switching, we go ahead and do it. If not, and
6846 there's already a terminal in place, we save the information to take effect
6849 If there's no terminal yet (for instance, during debugger initialization),
6850 we go ahead and set C<$console> and C<$tty> to the file indicated.
6856 if ( @_ and $term and $term->Features->{newTTY} ) {
6858 # This terminal supports switching to a new TTY.
6859 # Can be a list of two files, or on string containing both names,
6861 # XXX Should this perhaps be an assignment from @_?
6862 my ( $in, $out ) = shift;
6865 # Split list apart if supplied.
6866 ( $in, $out ) = split /,/, $in, 2;
6870 # Use the same file for both input and output.
6874 # Open file onto the debugger's filehandles, if you can.
6875 open IN, $in or die "cannot open `$in' for read: $!";
6876 open OUT, ">$out" or die "cannot open `$out' for write: $!";
6878 # Swap to the new filehandles.
6879 reset_IN_OUT( \*IN, \*OUT );
6881 # Save the setting for later.
6883 } ## end if (@_ and $term and $term...
6885 # Terminal doesn't support new TTY, or doesn't support readline.
6886 # Can't do it now, try restarting.
6887 &warn("Too late to set TTY, enabled on next `R'!\n") if $term and @_;
6889 # Useful if done through PERLDB_OPTS:
6890 $console = $tty = shift if @_;
6892 # Return whatever the TTY is.
6898 Sets the C<$notty> global, controlling whether or not the debugger tries to
6899 get a terminal to read from. If called after a terminal is already in place,
6900 we save the value to use it if we're restarted.
6906 &warn("Too late to set noTTY, enabled on next `R'!\n") if @_;
6908 $notty = shift if @_;
6914 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
6915 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
6916 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
6917 the value in case a restart is done so we can change it then.
6923 &warn("Too late to set ReadLine, enabled on next `R'!\n") if @_;
6927 } ## end sub ReadLine
6929 =head2 C<RemotePort>
6931 Sets the port that the debugger will try to connect to when starting up.
6932 If the terminal's already been set up, we can't do it, but we remember the
6933 setting in case the user does a restart.
6939 &warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
6941 $remoteport = shift if @_;
6943 } ## end sub RemotePort
6947 Checks with the terminal to see if C<Tk> is running, and returns true or
6948 false. Returns false if the current terminal doesn't support C<readline>.
6953 if ( ${ $term->Features }{tkRunning} ) {
6954 return $term->tkRunning(@_);
6958 print $OUT "tkRunning not supported by current ReadLine package.\n";
6961 } ## end sub tkRunning
6965 Sets nonstop mode. If a terminal's already been set up, it's too late; the
6966 debugger remembers the setting in case you restart, though.
6972 &warn("Too late to set up NonStop mode, enabled on next `R'!\n")
6975 $runnonstop = shift if @_;
6977 } ## end sub NonStop
6981 &warn("Some flag changes could not take effect until next 'R'!\n")
6984 $^P = parse_DollarCaretP_flags(shift) if @_;
6985 expand_DollarCaretP_flags($^P);
6990 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
6998 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
7005 Sets the shell escape command, and generates a printable copy to be used
7012 # If we got an argument, meta-quote it, and add '\b' if it
7013 # ends in a word character.
7015 $sh = quotemeta shift;
7016 $sh .= "\\b" if $sh =~ /\w$/;
7019 # Generate the printable version for the help:
7020 $psh = $sh; # copy it
7021 $psh =~ s/\\b$//; # Take off trailing \b if any
7022 $psh =~ s/\\(.)/$1/g; # De-escape
7023 $psh; # return the printable version
7024 } ## end sub shellBang
7028 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7029 was passed as the argument. (This means you can't override the terminal's
7035 if ( defined $term ) {
7037 # We don't want to show warning backtraces, but we do want die() ones.
7038 local ( $warnLevel, $dieLevel ) = ( 0, 1 );
7040 # No ornaments if the terminal doesn't support them.
7041 return '' unless $term->Features->{ornaments};
7042 eval { $term->ornaments(@_) } || '';
7045 # Use what was passed in if we can't determine it ourselves.
7049 } ## end sub ornaments
7051 =head2 C<recallCommand>
7053 Sets the recall command, and builds a printable version which will appear in
7060 # If there is input, metaquote it. Add '\b' if it ends with a word
7063 $rc = quotemeta shift;
7064 $rc .= "\\b" if $rc =~ /\w$/;
7067 # Build it into a printable version.
7068 $prc = $rc; # Copy it
7069 $prc =~ s/\\b$//; # Remove trailing \b
7070 $prc =~ s/\\(.)/$1/g; # Remove escapes
7071 $prc; # Return the printable version
7072 } ## end sub recallCommand
7074 =head2 C<LineInfo> - where the line number information goes
7076 Called with no arguments, returns the file or pipe that line info should go to.
7078 Called with an argument (a file or a pipe), it opens that onto the
7079 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7080 file or pipe again to the caller.
7085 return $lineinfo unless @_;
7088 # If this is a valid "thing to be opened for output", tack a
7089 # '>' onto the front.
7090 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7092 # If this is a pipe, the stream points to a slave editor.
7093 $slave_editor = ( $stream =~ /^\|/ );
7095 # Open it up and unbuffer it.
7096 open( LINEINFO, "$stream" ) || &warn("Cannot open `$stream' for write");
7097 $LINEINFO = \*LINEINFO;
7098 my $save = select($LINEINFO);
7102 # Hand the file or pipe back again.
7104 } ## end sub LineInfo
7106 =head1 COMMAND SUPPORT ROUTINES
7108 These subroutines provide functionality for various commands.
7110 =head2 C<list_modules>
7112 For the C<M> command: list modules loaded and their versions.
7113 Essentially just runs through the keys in %INC, picks each package's
7114 C<$VERSION> variable, gets the file name, and formats the information
7119 sub list_modules { # versions
7123 # keys are the "as-loaded" name, values are the fully-qualified path
7124 # to the file itself.
7126 $file = $_; # get the module name
7127 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
7128 s,/,::,g; # change '/' to '::'
7129 s/^perl5db$/DB/; # Special case: debugger
7130 # moves to package DB
7131 s/^Term::ReadLine::readline$/readline/; # simplify readline
7133 # If the package has a $VERSION package global (as all good packages
7134 # should!) decode it and save as partial message.
7135 if ( defined ${ $_ . '::VERSION' } ) {
7136 $version{$file} = "${ $_ . '::VERSION' } from ";
7139 # Finish up the message with the file the package came from.
7140 $version{$file} .= $INC{$file};
7141 } ## end for (keys %INC)
7143 # Hey, dumpit() formats a hash nicely, so why not use it?
7144 dumpit( $OUT, \%version );
7145 } ## end sub list_modules
7149 Sets up the monster string used to format and print the help.
7151 =head3 HELP MESSAGE FORMAT
7153 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
7154 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
7155 easy to parse and portable, but which still allows the help to be a little
7156 nicer than just plain text.
7158 Essentially, you define the command name (usually marked up with C<< B<> >>
7159 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
7160 newline. The descriptive text can also be marked up in the same way. If you
7161 need to continue the descriptive text to another line, start that line with
7162 just tabs and then enter the marked-up text.
7164 If you are modifying the help text, I<be careful>. The help-string parser is
7165 not very sophisticated, and if you don't follow these rules it will mangle the
7166 help beyond hope until you fix the string.
7172 # XXX: make sure there are tabs between the command and explanation,
7173 # or print_help will screw up your formatting if you have
7174 # eeevil ornaments enabled. This is an insane mess.
7177 Help is currently only available for the new 5.8 command set.
7178 No help is available for the old command set.
7179 We assume you know what you're doing if you switch to it.
7182 B<s> [I<expr>] Single step [in I<expr>].
7183 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7184 <B<CR>> Repeat last B<n> or B<s> command.
7185 B<r> Return from current subroutine.
7186 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7187 at the specified position.
7188 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7189 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7190 B<l> I<line> List single I<line>.
7191 B<l> I<subname> List first window of lines from subroutine.
7192 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7193 B<l> List next window of lines.
7194 B<-> List previous window of lines.
7195 B<v> [I<line>] View window around I<line>.
7196 B<.> Return to the executed line.
7197 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7198 I<filename> may be either the full name of the file, or a regular
7199 expression matching the full file name:
7200 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7201 Evals (with saved bodies) are considered to be filenames:
7202 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7203 (in the order of execution).
7204 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7205 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7206 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
7207 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7208 B<t> Toggle trace mode.
7209 B<t> I<expr> Trace through execution of I<expr>.
7210 B<b> Sets breakpoint on current line)
7211 B<b> [I<line>] [I<condition>]
7212 Set breakpoint; I<line> defaults to the current execution line;
7213 I<condition> breaks if it evaluates to true, defaults to '1'.
7214 B<b> I<subname> [I<condition>]
7215 Set breakpoint at first line of subroutine.
7216 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7217 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7218 B<b> B<postpone> I<subname> [I<condition>]
7219 Set breakpoint at first line of subroutine after
7221 B<b> B<compile> I<subname>
7222 Stop after the subroutine is compiled.
7223 B<B> [I<line>] Delete the breakpoint for I<line>.
7224 B<B> I<*> Delete all breakpoints.
7225 B<a> [I<line>] I<command>
7226 Set an action to be done before the I<line> is executed;
7227 I<line> defaults to the current execution line.
7228 Sequence is: check for breakpoint/watchpoint, print line
7229 if necessary, do action, prompt user if necessary,
7232 B<A> [I<line>] Delete the action for I<line>.
7233 B<A> I<*> Delete all actions.
7234 B<w> I<expr> Add a global watch-expression.
7236 B<W> I<expr> Delete a global watch-expression.
7237 B<W> I<*> Delete all watch-expressions.
7238 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7239 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7240 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7241 B<x> I<expr> Evals expression in list context, dumps the result.
7242 B<m> I<expr> Evals expression in list context, prints methods callable
7243 on the first element of the result.
7244 B<m> I<class> Prints methods callable via the given class.
7245 B<M> Show versions of loaded modules.
7246 B<i> I<class> Prints nested parents of given class.
7247 B<e> Display current thread id.
7248 B<E> Display all thread ids the current one will be identified: <n>.
7249 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7251 B<<> ? List Perl commands to run before each prompt.
7252 B<<> I<expr> Define Perl command to run before each prompt.
7253 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7254 B<< *> Delete the list of perl commands to run before each prompt.
7255 B<>> ? List Perl commands to run after each prompt.
7256 B<>> I<expr> Define Perl command to run after each prompt.
7257 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7258 B<>>B< *> Delete the list of Perl commands to run after each prompt.
7259 B<{> I<db_command> Define debugger command to run before each prompt.
7260 B<{> ? List debugger commands to run before each prompt.
7261 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7262 B<{ *> Delete the list of debugger commands to run before each prompt.
7263 B<$prc> I<number> Redo a previous command (default previous command).
7264 B<$prc> I<-number> Redo number'th-to-last command.
7265 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7266 See 'B<O> I<recallCommand>' too.
7267 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7272 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7274 See 'B<O> I<shellBang>' too.
7275 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7276 B<save> I<file> Save current debugger session (actual history) to I<file>.
7277 B<rerun> Rerun session to current position.
7278 B<rerun> I<n> Rerun session to numbered command.
7279 B<rerun> I<-n> Rerun session to number'th-to-last command.
7280 B<H> I<-number> Display last number commands (default all).
7281 B<H> I<*> Delete complete history.
7282 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7283 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7284 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7285 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7286 I<command> Execute as a perl statement in current package.
7287 B<R> Pure-man-restart of debugger, some of debugger state
7288 and command-line options may be lost.
7289 Currently the following settings are preserved:
7290 history, breakpoints and actions, debugger B<O>ptions
7291 and the following command-line options: I<-w>, I<-I>, I<-e>.
7293 B<o> [I<opt>] ... Set boolean option to true
7294 B<o> [I<opt>B<?>] Query options
7295 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7296 Set options. Use quotes if spaces in value.
7297 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7298 I<pager> program for output of \"|cmd\";
7299 I<tkRunning> run Tk while prompting (with ReadLine);
7300 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7301 I<inhibit_exit> Allows stepping off the end of the script.
7302 I<ImmediateStop> Debugger should stop as early as possible.
7303 I<RemotePort> Remote hostname:port for remote debugging
7304 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7305 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7306 I<compactDump>, I<veryCompact> change style of array and hash dump;
7307 I<globPrint> whether to print contents of globs;
7308 I<DumpDBFiles> dump arrays holding debugged files;
7309 I<DumpPackages> dump symbol tables of packages;
7310 I<DumpReused> dump contents of \"reused\" addresses;
7311 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7312 I<bareStringify> Do not print the overload-stringified value;
7313 Other options include:
7314 I<PrintRet> affects printing of return value after B<r> command,
7315 I<frame> affects printing messages on subroutine entry/exit.
7316 I<AutoTrace> affects printing messages on possible breaking points.
7317 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7318 I<ornaments> affects screen appearance of the command line.
7319 I<CreateTTY> bits control attempts to create a new TTY on events:
7320 1: on fork() 2: debugger is started inside debugger
7322 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7323 You can put additional initialization options I<TTY>, I<noTTY>,
7324 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7325 `B<R>' after you set them).
7327 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7328 B<h> Summary of debugger commands.
7329 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7330 B<h h> Long help for debugger commands
7331 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7332 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7333 Set B<\$DB::doccmd> to change viewer.
7335 Type `|h h' for a paged display if this was too hard to read.
7337 "; # Fix balance of vi % matching: }}}}
7339 # note: tabs in the following section are not-so-helpful
7340 $summary = <<"END_SUM";
7341 I<List/search source lines:> I<Control script execution:>
7342 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7343 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7344 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
7345 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7346 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7347 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
7348 I<Debugger controls:> B<L> List break/watch/actions
7349 B<o> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7350 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7351 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
7352 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7353 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
7354 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
7355 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
7356 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7357 B<q> or B<^D> Quit B<R> Attempt a restart
7358 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7359 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7360 B<p> I<expr> Print expression (uses script's current package).
7361 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7362 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7363 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
7364 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7365 B<e> Display thread id B<E> Display all thread ids.
7366 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7369 # ')}}; # Fix balance of vi % matching
7371 # and this is really numb...
7374 B<s> [I<expr>] Single step [in I<expr>].
7375 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7376 B<CR>> Repeat last B<n> or B<s> command.
7377 B<r> Return from current subroutine.
7378 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7379 at the specified position.
7380 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7381 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7382 B<l> I<line> List single I<line>.
7383 B<l> I<subname> List first window of lines from subroutine.
7384 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7385 B<l> List next window of lines.
7386 B<-> List previous window of lines.
7387 B<w> [I<line>] List window around I<line>.
7388 B<.> Return to the executed line.
7389 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7390 I<filename> may be either the full name of the file, or a regular
7391 expression matching the full file name:
7392 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7393 Evals (with saved bodies) are considered to be filenames:
7394 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7395 (in the order of execution).
7396 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7397 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7398 B<L> List all breakpoints and actions.
7399 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7400 B<t> Toggle trace mode.
7401 B<t> I<expr> Trace through execution of I<expr>.
7402 B<b> [I<line>] [I<condition>]
7403 Set breakpoint; I<line> defaults to the current execution line;
7404 I<condition> breaks if it evaluates to true, defaults to '1'.
7405 B<b> I<subname> [I<condition>]
7406 Set breakpoint at first line of subroutine.
7407 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7408 B<b> B<load> I<filename> Set breakpoint on `require'ing the given file.
7409 B<b> B<postpone> I<subname> [I<condition>]
7410 Set breakpoint at first line of subroutine after
7412 B<b> B<compile> I<subname>
7413 Stop after the subroutine is compiled.
7414 B<d> [I<line>] Delete the breakpoint for I<line>.
7415 B<D> Delete all breakpoints.
7416 B<a> [I<line>] I<command>
7417 Set an action to be done before the I<line> is executed;
7418 I<line> defaults to the current execution line.
7419 Sequence is: check for breakpoint/watchpoint, print line
7420 if necessary, do action, prompt user if necessary,
7422 B<a> [I<line>] Delete the action for I<line>.
7423 B<A> Delete all actions.
7424 B<W> I<expr> Add a global watch-expression.
7425 B<W> Delete all watch-expressions.
7426 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7427 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7428 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7429 B<x> I<expr> Evals expression in list context, dumps the result.
7430 B<m> I<expr> Evals expression in list context, prints methods callable
7431 on the first element of the result.
7432 B<m> I<class> Prints methods callable via the given class.
7434 B<<> ? List Perl commands to run before each prompt.
7435 B<<> I<expr> Define Perl command to run before each prompt.
7436 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7437 B<>> ? List Perl commands to run after each prompt.
7438 B<>> I<expr> Define Perl command to run after each prompt.
7439 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7440 B<{> I<db_command> Define debugger command to run before each prompt.
7441 B<{> ? List debugger commands to run before each prompt.
7442 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7443 B<$prc> I<number> Redo a previous command (default previous command).
7444 B<$prc> I<-number> Redo number'th-to-last command.
7445 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7446 See 'B<O> I<recallCommand>' too.
7447 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7452 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7454 See 'B<O> I<shellBang>' too.
7455 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7456 B<H> I<-number> Display last number commands (default all).
7457 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7458 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7459 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7460 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7461 I<command> Execute as a perl statement in current package.
7462 B<v> Show versions of loaded modules.
7463 B<R> Pure-man-restart of debugger, some of debugger state
7464 and command-line options may be lost.
7465 Currently the following settings are preserved:
7466 history, breakpoints and actions, debugger B<O>ptions
7467 and the following command-line options: I<-w>, I<-I>, I<-e>.
7469 B<O> [I<opt>] ... Set boolean option to true
7470 B<O> [I<opt>B<?>] Query options
7471 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7472 Set options. Use quotes if spaces in value.
7473 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7474 I<pager> program for output of \"|cmd\";
7475 I<tkRunning> run Tk while prompting (with ReadLine);
7476 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7477 I<inhibit_exit> Allows stepping off the end of the script.
7478 I<ImmediateStop> Debugger should stop as early as possible.
7479 I<RemotePort> Remote hostname:port for remote debugging
7480 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7481 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7482 I<compactDump>, I<veryCompact> change style of array and hash dump;
7483 I<globPrint> whether to print contents of globs;
7484 I<DumpDBFiles> dump arrays holding debugged files;
7485 I<DumpPackages> dump symbol tables of packages;
7486 I<DumpReused> dump contents of \"reused\" addresses;
7487 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7488 I<bareStringify> Do not print the overload-stringified value;
7489 Other options include:
7490 I<PrintRet> affects printing of return value after B<r> command,
7491 I<frame> affects printing messages on subroutine entry/exit.
7492 I<AutoTrace> affects printing messages on possible breaking points.
7493 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7494 I<ornaments> affects screen appearance of the command line.
7495 I<CreateTTY> bits control attempts to create a new TTY on events:
7496 1: on fork() 2: debugger is started inside debugger
7498 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7499 You can put additional initialization options I<TTY>, I<noTTY>,
7500 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7501 `B<R>' after you set them).
7503 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7504 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7505 B<h h> Summary of debugger commands.
7506 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7507 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7508 Set B<\$DB::doccmd> to change viewer.
7510 Type `|h' for a paged display if this was too hard to read.
7512 "; # Fix balance of vi % matching: }}}}
7514 # note: tabs in the following section are not-so-helpful
7515 $pre580_summary = <<"END_SUM";
7516 I<List/search source lines:> I<Control script execution:>
7517 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7518 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7519 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
7520 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7521 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7522 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
7523 I<Debugger controls:> B<L> List break/watch/actions
7524 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7525 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7526 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
7527 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7528 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
7529 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
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>]\".
7538 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7539 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7542 # ')}}; # Fix balance of vi % matching
7544 } ## end sub sethelp
7546 =head2 C<print_help()>
7548 Most of what C<print_help> does is just text formatting. It finds the
7549 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
7550 terminal control characters to simulate them (courtesy of
7551 C<Term::ReadLine::TermCap>).
7558 # Restore proper alignment destroyed by eeevil I<> and B<>
7559 # ornaments: A pox on both their houses!
7561 # A help command will have everything up to and including
7562 # the first tab sequence padded into a field 16 (or if indented 20)
7563 # wide. If it's wider than that, an extra space will be added.
7565 ^ # only matters at start of line
7566 ( \040{4} | \t )* # some subcommands are indented
7567 ( < ? # so <CR> works
7568 [BI] < [^\t\n] + ) # find an eeevil ornament
7569 ( \t+ ) # original separation, discarded
7570 ( .* ) # this will now start (no earlier) than
7573 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
7574 my $clean = $command;
7575 $clean =~ s/[BI]<([^>]*)>/$1/g;
7577 # replace with this whole string:
7578 ($leadwhite ? " " x 4 : "")
7580 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
7585 s{ # handle bold ornaments
7586 B < ( [^>] + | > ) >
7588 $Term::ReadLine::TermCap::rl_term_set[2]
7590 . $Term::ReadLine::TermCap::rl_term_set[3]
7593 s{ # handle italic ornaments
7594 I < ( [^>] + | > ) >
7596 $Term::ReadLine::TermCap::rl_term_set[0]
7598 . $Term::ReadLine::TermCap::rl_term_set[1]
7603 } ## end sub print_help
7607 This routine does a lot of gyrations to be sure that the pager is C<less>.
7608 It checks for C<less> masquerading as C<more> and records the result in
7609 C<$ENV{LESS}> so we don't have to go through doing the stats again.
7615 # We already know if this is set.
7616 return if defined $ENV{LESS} && $ENV{LESS} =~ /r/;
7618 # Pager is less for sure.
7619 my $is_less = $pager =~ /\bless\b/;
7620 if ( $pager =~ /\bmore\b/ ) {
7622 # Nope, set to more. See what's out there.
7623 my @st_more = stat('/usr/bin/more');
7624 my @st_less = stat('/usr/bin/less');
7626 # is it really less, pretending to be more?
7629 && $st_more[0] == $st_less[0]
7630 && $st_more[1] == $st_less[1];
7631 } ## end if ($pager =~ /\bmore\b/)
7633 # changes environment!
7634 # 'r' added so we don't do (slow) stats again.
7635 $ENV{LESS} .= 'r' if $is_less;
7636 } ## end sub fix_less
7638 =head1 DIE AND WARN MANAGEMENT
7642 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
7643 to debug a debugger problem.
7645 It does its best to report the error that occurred, and then forces the
7646 program, debugger, and everything to die.
7652 # No entry/exit messages.
7655 # No return value prints.
7658 # set the abort signal handling to the default (just terminate).
7659 $SIG{'ABRT'} = 'DEFAULT';
7661 # If we enter the signal handler recursively, kill myself with an
7662 # abort signal (so we just terminate).
7663 kill 'ABRT', $$ if $panic++;
7665 # If we can show detailed info, do so.
7666 if ( defined &Carp::longmess ) {
7668 # Don't recursively enter the warn handler, since we're carping.
7669 local $SIG{__WARN__} = '';
7671 # Skip two levels before reporting traceback: we're skipping
7672 # mydie and confess.
7673 local $Carp::CarpLevel = 2; # mydie + confess
7675 # Tell us all about it.
7676 &warn( Carp::longmess("Signal @_") );
7679 # No Carp. Tell us about the signal as best we can.
7682 print $DB::OUT "Got signal @_\n";
7687 } ## end sub diesignal
7691 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
7692 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
7698 # No entry/exit trace.
7701 # No return value printing.
7704 # Turn off warn and die handling to prevent recursive entries to this
7706 local $SIG{__WARN__} = '';
7707 local $SIG{__DIE__} = '';
7709 # Load Carp if we can. If $^S is false (current thing being compiled isn't
7710 # done yet), we may not be able to do a require.
7711 eval { require Carp }
7712 if defined $^S; # If error/warning during compilation,
7713 # require may be broken.
7715 # Use the core warn() unless Carp loaded OK.
7717 "\nCannot print stack trace, load with -MCarp option to see stack" ),
7719 unless defined &Carp::longmess;
7721 # Save the current values of $single and $trace, and then turn them off.
7722 my ( $mysingle, $mytrace ) = ( $single, $trace );
7726 # We can call Carp::longmess without its being "debugged" (which we
7727 # don't want - we just want to use it!). Capture this for later.
7728 my $mess = Carp::longmess(@_);
7730 # Restore $single and $trace to their original values.
7731 ( $single, $trace ) = ( $mysingle, $mytrace );
7733 # Use the debugger's own special way of printing warnings to print
7734 # the stack trace message.
7740 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
7741 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
7742 single stepping and tracing during the call to C<Carp::longmess> to avoid
7743 debugging it - we just want to use it.
7745 If C<dieLevel> is zero, we let the program being debugged handle the
7746 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
7747 the debugger takes over all exception handling, printing a backtrace and
7748 displaying the exception via its C<dbwarn()> routine.
7755 local $SIG{__DIE__} = '';
7756 local $SIG{__WARN__} = '';
7760 if ( $dieLevel > 2 ) {
7761 local $SIG{__WARN__} = \&dbwarn;
7762 &warn(@_); # Yell no matter what
7765 if ( $dieLevel < 2 ) {
7766 die @_ if $^S; # in eval propagate
7769 # The code used to check $^S to see if compiliation of the current thing
7770 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
7771 eval { require Carp };
7774 "\nCannot print stack trace, load with -MCarp option to see stack" )
7775 unless defined &Carp::longmess;
7777 # We do not want to debug this chunk (automatic disabling works
7778 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
7779 # get the stack trace from Carp::longmess (if possible), restore $signal
7780 # and $trace, and then die with the stack trace.
7781 my ( $mysingle, $mytrace ) = ( $single, $trace );
7787 package Carp; # Do not include us in the list
7788 eval { $mess = Carp::longmess(@_); };
7790 ( $single, $trace ) = ( $mysingle, $mytrace );
7794 =head2 C<warnlevel()>
7796 Set the C<$DB::warnLevel> variable that stores the value of the
7797 C<warnLevel> option. Calling C<warnLevel()> with a positive value
7798 results in the debugger taking over all warning handlers. Setting
7799 C<warnLevel> to zero leaves any warning handlers set up by the program
7800 being debugged in place.
7806 $prevwarn = $SIG{__WARN__} unless $warnLevel;
7809 $SIG{__WARN__} = \&DB::dbwarn;
7812 $SIG{__WARN__} = $prevwarn;
7814 undef $SIG{__WARN__};
7818 } ## end sub warnLevel
7822 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
7823 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
7824 zero lets you use your own C<die()> handler.
7831 $prevdie = $SIG{__DIE__} unless $dieLevel;
7835 # Always set it to dbdie() for non-zero values.
7836 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
7838 # No longer exists, so don't try to use it.
7839 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
7841 # If we've finished initialization, mention that stack dumps
7842 # are enabled, If dieLevel is 1, we won't stack dump if we die
7844 print $OUT "Stack dump during die enabled",
7845 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
7848 # XXX This is probably obsolete, given that diehard() is gone.
7849 print $OUT "Dump printed too.\n" if $dieLevel > 2;
7850 } ## end if ($dieLevel)
7852 # Put the old one back if there was one.
7854 $SIG{__DIE__} = $prevdie;
7855 print $OUT "Default die handler restored.\n";
7857 undef $SIG{__DIE__};
7858 print $OUT "Die handler removed.\n";
7862 } ## end sub dieLevel
7864 =head2 C<signalLevel>
7866 Number three in a series: set C<signalLevel> to zero to keep your own
7867 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
7868 takes over and handles them with C<DB::diesignal()>.
7874 $prevsegv = $SIG{SEGV} unless $signalLevel;
7875 $prevbus = $SIG{BUS} unless $signalLevel;
7876 $signalLevel = shift;
7878 $SIG{SEGV} = \&DB::diesignal;
7879 $SIG{BUS} = \&DB::diesignal;
7882 $SIG{SEGV} = $prevsegv;
7883 $SIG{BUS} = $prevbus;
7887 } ## end sub signalLevel
7889 =head1 SUBROUTINE DECODING SUPPORT
7891 These subroutines are used during the C<x> and C<X> commands to try to
7892 produce as much information as possible about a code reference. They use
7893 L<Devel::Peek> to try to find the glob in which this code reference lives
7894 (if it does) - this allows us to actually code references which correspond
7895 to named subroutines (including those aliased via glob assignment).
7897 =head2 C<CvGV_name()>
7899 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
7900 via that routine. If this fails, return the reference again (when the
7901 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
7907 my $name = CvGV_name_or_bust($in);
7908 defined $name ? $name : $in;
7911 =head2 C<CvGV_name_or_bust> I<coderef>
7913 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
7914 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
7915 find a glob for this ref.
7917 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
7921 sub CvGV_name_or_bust {
7923 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
7924 return unless ref $in;
7925 $in = \&$in; # Hard reference...
7926 eval { require Devel::Peek; 1 } or return;
7927 my $gv = Devel::Peek::CvGV($in) or return;
7928 *$gv{PACKAGE} . '::' . *$gv{NAME};
7929 } ## end sub CvGV_name_or_bust
7933 A utility routine used in various places; finds the file where a subroutine
7934 was defined, and returns that filename and a line-number range.
7936 Tries to use C<@sub> first; if it can't find it there, it tries building a
7937 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
7938 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
7939 this way, it brute-force searches C<%sub>, checking for identical references.
7946 return unless defined &$subr;
7947 my $name = CvGV_name_or_bust($subr);
7949 $data = $sub{$name} if defined $name;
7950 return $data if defined $data;
7953 $subr = \&$subr; # Hard reference
7956 $s = $_, last if $subr eq \&$_;
7960 } ## end sub find_sub
7964 A subroutine that uses the utility function C<methods_via> to find all the
7965 methods in the class corresponding to the current reference and in
7972 # Figure out the class - either this is the class or it's a reference
7973 # to something blessed into that class.
7975 $class = ref $class if ref $class;
7979 # Show the methods that this class has.
7980 methods_via( $class, '', 1 );
7982 # Show the methods that UNIVERSAL has.
7983 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
7984 } ## end sub methods
7986 =head2 C<methods_via($class, $prefix, $crawl_upward)>
7988 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
7989 all the parent class methods. C<$class> is the name of the next class to
7990 try; C<$prefix> is the message prefix, which gets built up as we go up the
7991 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
7992 higher in the C<@ISA> tree, 0 if we should stop.
7998 # If we've processed this class already, just quit.
8000 return if $seen{$class}++;
8002 # This is a package that is contributing the methods we're about to print.
8004 my $prepend = $prefix ? "via $prefix: " : '';
8007 # Extract from all the symbols in this class.
8008 while (my ($name, $glob) = each %{"${class}::"}) {
8009 # references directly in the symbol table are Proxy Constant
8010 # Subroutines, and are by their very nature defined
8011 # Otherwise, check if the thing is a typeglob, and if it is, it decays
8012 # to a subroutine reference, which can be tested by defined.
8013 # $glob might also be the value -1 (from sub foo;)
8014 # or (say) '$$' (from sub foo ($$);)
8015 # \$glob will be SCALAR in both cases.
8016 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob))
8017 && !$seen{$name}++) {
8018 push @to_print, "$prepend$name\n";
8025 print $DB::OUT $_ foreach sort @to_print;
8028 # If the $crawl_upward argument is false, just quit here.
8029 return unless shift;
8031 # $crawl_upward true: keep going up the tree.
8032 # Find all the classes this one is a subclass of.
8033 for $name ( @{"${class}::ISA"} ) {
8035 # Set up the new prefix.
8036 $prepend = $prefix ? $prefix . " -> $name" : $name;
8038 # Crawl up the tree and keep trying to crawl up.
8039 methods_via( $name, $prepend, 1 );
8041 } ## end sub methods_via
8043 =head2 C<setman> - figure out which command to use to show documentation
8045 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8050 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|MacOS|NetWare)\z/s
8051 ? "man" # O Happy Day!
8052 : "perldoc"; # Alas, poor unfortunates
8055 =head2 C<runman> - run the appropriate command to show documentation
8057 Accepts a man page name; runs the appropriate command to display it (set up
8058 during debugger initialization). Uses C<DB::system> to avoid mucking up the
8059 program's STDIN and STDOUT.
8066 &system("$doccmd $doccmd");
8070 # this way user can override, like with $doccmd="man -Mwhatever"
8071 # or even just "man " to disable the path check.
8072 unless ( $doccmd eq 'man' ) {
8073 &system("$doccmd $page");
8077 $page = 'perl' if lc($page) eq 'help';
8080 my $man1dir = $Config::Config{'man1dir'};
8081 my $man3dir = $Config::Config{'man3dir'};
8082 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
8084 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
8085 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
8086 chop $manpath if $manpath;
8088 # harmless if missing, I figure
8089 my $oldpath = $ENV{MANPATH};
8090 $ENV{MANPATH} = $manpath if $manpath;
8091 my $nopathopt = $^O =~ /dunno what goes here/;
8096 # I just *know* there are men without -M
8097 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8102 unless ( $page =~ /^perl\w/ ) {
8103 # do it this way because its easier to slurp in to keep up to date - clunky though.
8241 if (grep { $page eq $_ } @pods) {
8243 CORE::system( $doccmd,
8244 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8246 } ## end if (grep { $page eq $_...
8247 } ## end unless ($page =~ /^perl\w/)
8248 } ## end if (CORE::system($doccmd...
8249 if ( defined $oldpath ) {
8250 $ENV{MANPATH} = $manpath;
8253 delete $ENV{MANPATH};
8257 #use Carp; # This did break, left for debugging
8259 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
8261 Because of the way the debugger interface to the Perl core is designed, any
8262 debugger package globals that C<DB::sub()> requires have to be defined before
8263 any subroutines can be called. These are defined in the second C<BEGIN> block.
8265 This block sets things up so that (basically) the world is sane
8266 before the debugger starts executing. We set up various variables that the
8267 debugger has to have set up before the Perl core starts running:
8273 The debugger's own filehandles (copies of STD and STDOUT for now).
8277 Characters for shell escapes, the recall command, and the history command.
8281 The maximum recursion depth.
8285 The size of a C<w> command's window.
8289 The before-this-line context to be printed in a C<v> (view a window around this line) command.
8293 The fact that we're not in a sub at all right now.
8297 The default SIGINT handler for the debugger.
8301 The appropriate value of the flag in C<$^D> that says the debugger is running
8305 The current debugger recursion level
8309 The list of postponed items and the C<$single> stack (XXX define this)
8313 That we want no return values and no subroutine entry/exit trace.
8319 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
8321 BEGIN { # This does not compile, alas. (XXX eh?)
8322 $IN = \*STDIN; # For bugs before DB::OUT has been opened
8323 $OUT = \*STDERR; # For errors before DB::OUT has been opened
8325 # Define characters used by command parsing.
8326 $sh = '!'; # Shell escape (does not work)
8327 $rc = ','; # Recall command (does not work)
8328 @hist = ('?'); # Show history (does not work)
8329 @truehist = (); # Can be saved for replay (per session)
8331 # This defines the point at which you get the 'deep recursion'
8332 # warning. It MUST be defined or the debugger will not load.
8335 # Number of lines around the current one that are shown in the
8339 # How much before-the-current-line context the 'v' command should
8340 # use in calculating the start of the window it will display.
8343 # We're not in any sub yet, but we need this to be a defined value.
8346 # Set up the debugger's interrupt handler. It simply sets a flag
8347 # ($signal) that DB::DB() will check before each command is executed.
8348 $SIG{INT} = \&DB::catch;
8350 # The following lines supposedly, if uncommented, allow the debugger to
8351 # debug itself. Perhaps we can try that someday.
8352 # This may be enabled to debug debugger:
8353 #$warnLevel = 1 unless defined $warnLevel;
8354 #$dieLevel = 1 unless defined $dieLevel;
8355 #$signalLevel = 1 unless defined $signalLevel;
8357 # This is the flag that says "a debugger is running, please call
8358 # DB::DB and DB::sub". We will turn it on forcibly before we try to
8359 # execute anything in the user's context, because we always want to
8361 $db_stop = 0; # Compiler warning ...
8362 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
8364 # This variable records how many levels we're nested in debugging. Used
8365 # Used in the debugger prompt, and in determining whether it's all over or
8367 $level = 0; # Level of recursive debugging
8369 # "Triggers bug (?) in perl if we postpone this until runtime."
8370 # XXX No details on this yet, or whether we should fix the bug instead
8371 # of work around it. Stay tuned.
8372 @postponed = @stack = (0);
8374 # Used to track the current stack depth using the auto-stacked-variable
8376 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
8378 # Don't print return values on exiting a subroutine.
8381 # No extry/exit tracing.
8386 BEGIN { $^W = $ini_warn; } # Switch warnings back
8388 =head1 READLINE SUPPORT - COMPLETION FUNCTION
8392 C<readline> support - adds command completion to basic C<readline>.
8394 Returns a list of possible completions to C<readline> when invoked. C<readline>
8395 will print the longest common substring following the text already entered.
8397 If there is only a single possible completion, C<readline> will use it in full.
8399 This code uses C<map> and C<grep> heavily to create lists of possible
8400 completion. Think LISP in this section.
8406 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
8407 # $text is the text to be completed.
8408 # $line is the incoming line typed by the user.
8409 # $start is the start of the text to be completed in the incoming line.
8410 my ( $text, $line, $start ) = @_;
8412 # Save the initial text.
8413 # The search pattern is current package, ::, extract the next qualifier
8414 # Prefix and pack are set to undef.
8415 my ( $itext, $search, $prefix, $pack ) =
8416 ( $text, "^\Q${'package'}::\E([^:]+)\$" );
8418 =head3 C<b postpone|compile>
8424 Find all the subroutines that might match in this package
8428 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
8432 Include all the rest of the subs that are known
8436 C<grep> out the ones that match the text we have so far
8440 Return this as the list of possible completions
8446 return sort grep /^\Q$text/, ( keys %sub ),
8447 qw(postpone load compile), # subroutines
8448 ( map { /$search/ ? ($1) : () } keys %sub )
8449 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
8453 Get all the possible files from C<@INC> as it currently stands and
8454 select the ones that match the text so far.
8458 return sort grep /^\Q$text/, values %INC # files
8459 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
8461 =head3 C<V> (list variable) and C<m> (list modules)
8463 There are two entry points for these commands:
8465 =head4 Unqualified package names
8467 Get the top-level packages and grab everything that matches the text
8468 so far. For each match, recursively complete the partial packages to
8469 get all possible matching packages. Return this sorted list.
8473 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8474 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
8475 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
8477 =head4 Qualified package names
8479 Take a partially-qualified package and find all subpackages for it
8480 by getting all the subpackages for the package so far, matching all
8481 the subpackages against the text, and discarding all of them which
8482 start with 'main::'. Return this list.
8486 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8487 grep !/^main::/, grep /^\Q$text/,
8488 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () } keys %{ $prefix . '::' }
8489 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
8490 and $text =~ /^(.*[^:])::?(\w*)$/
8493 =head3 C<f> - switch files
8495 Here, we want to get a fully-qualified filename for the C<f> command.
8500 =item 1. The original source file itself
8502 =item 2. A file from C<@INC>
8504 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
8510 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
8511 # We might possibly want to switch to an eval (which has a "filename"
8512 # like '(eval 9)'), so we may need to clean up the completion text
8513 # before proceeding.
8514 $prefix = length($1) - length($text);
8519 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
8520 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
8521 out of C<%main::>, add the initial source file, and extract the ones that
8522 match the completion text so far.
8527 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
8529 } ## end if ($line =~ /^\|*f\s+(.*)/)
8531 =head3 Subroutine name completion
8533 We look through all of the defined subs (the keys of C<%sub>) and
8534 return both all the possible matches to the subroutine name plus
8535 all the matches qualified to the current package.
8539 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
8540 $text = substr $text, 1;
8542 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
8544 map { /$search/ ? ($1) : () }
8547 } ## end if ((substr $text, 0, ...
8549 =head3 Scalar, array, and hash completion: partially qualified package
8551 Much like the above, except we have to do a little more cleanup:
8555 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
8563 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
8567 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
8573 Figure out the prefix vs. what needs completing.
8577 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
8584 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
8588 my @out = map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
8595 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.
8599 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8600 return db_complete( $out[0], $line, $start );
8603 # Return the list of possibles.
8606 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
8612 =head3 Symbol completion: current package or package C<main>.
8616 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
8623 If it's C<main>, delete main to just get C<::> leading.
8627 $pack = ( $package eq 'main' ? '' : $package ) . '::';
8633 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
8637 $prefix = substr $text, 0, 1;
8638 $text = substr $text, 1;
8646 We look for the lexical scope above DB::DB and auto-complete lexical variables
8647 if PadWalker could be loaded.
8651 if (not $text =~ /::/ and eval "require PadWalker; 1" and not $@ ) {
8654 my @info = caller($level);
8658 last if $info[3] eq 'DB::DB';
8661 my $lexicals = PadWalker::peek_my($level);
8662 push @out, grep /^\Q$prefix$text/, keys %$lexicals;
8670 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
8674 push @out, map "$prefix$_", grep /^\Q$text/,
8675 ( grep /^_?[a-zA-Z]/, keys %$pack ),
8676 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
8680 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
8686 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8687 return db_complete( $out[0], $line, $start );
8690 # Return the list of possibles.
8692 } ## end if ($text =~ /^[\$@%]/)
8696 We use C<option_val()> to look up the current value of the option. If there's
8697 only a single value, we complete the command in such a way that it is a
8698 complete command for setting the option in question. If there are multiple
8699 possible values, we generate a command consisting of the option plus a trailing
8700 question mark, which, if executed, will list the current value of the option.
8704 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
8705 { # Options after space
8706 # We look for the text to be matched in the list of possible options,
8707 # and fetch the current value.
8708 my @out = grep /^\Q$text/, @options;
8709 my $val = option_val( $out[0], undef );
8711 # Set up a 'query option's value' command.
8713 if ( not defined $val or $val =~ /[\n\r]/ ) {
8715 # There's really nothing else we can do.
8718 # We have a value. Create a proper option-setting command.
8719 elsif ( $val =~ /\s/ ) {
8721 # XXX This may be an extraneous variable.
8724 # We'll want to quote the string (because of the embedded
8725 # whtespace), but we want to make sure we don't end up with
8726 # mismatched quote characters. We try several possibilities.
8727 foreach $l ( split //, qq/\"\'\#\|/ ) {
8729 # If we didn't find this quote character in the value,
8730 # quote it using this quote character.
8731 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
8733 } ## end elsif ($val =~ /\s/)
8735 # Don't need any quotes.
8740 # If there were multiple possible values, return '? ', which
8741 # makes the command into a query command. If there was just one,
8742 # have readline append that.
8743 $rl_attribs->{completer_terminator_character} =
8744 ( @out == 1 ? $out : '? ' );
8746 # Return list of possibilities.
8748 } ## end if ((substr $line, 0, ...
8750 =head3 Filename completion
8752 For entering filenames. We simply call C<readline>'s C<filename_list()>
8753 method with the completion text to get the possible completions.
8757 return $term->filename_list($text); # filenames
8759 } ## end sub db_complete
8761 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
8763 Functions that possibly ought to be somewhere else.
8773 print $OUT "Use `q' to quit or `R' to restart. `h q' for details.\n";
8778 If we have $ini_pids, save it in the environment; else remove it from the
8779 environment. Used by the C<R> (restart) command.
8784 if ( defined($ini_pids) ) {
8785 $ENV{PERLDB_PIDS} = $ini_pids;
8788 delete( $ENV{PERLDB_PIDS} );
8790 } ## end sub clean_ENV
8792 # PERLDBf_... flag names from perl.h
8793 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
8796 %DollarCaretP_flags = (
8797 PERLDBf_SUB => 0x01, # Debug sub enter/exit
8798 PERLDBf_LINE => 0x02, # Keep line #
8799 PERLDBf_NOOPT => 0x04, # Switch off optimizations
8800 PERLDBf_INTER => 0x08, # Preserve more data
8801 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
8802 PERLDBf_SINGLE => 0x20, # Start with single-step on
8803 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
8804 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
8805 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
8806 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
8807 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"}
8808 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO
8810 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger
8811 # doesn't need to set it. It's provided for the benefit of profilers and
8812 # other code analysers.
8814 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
8817 sub parse_DollarCaretP_flags {
8822 foreach my $f ( split /\s*\|\s*/, $flags ) {
8824 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
8827 elsif ( $f =~ /^(\d+)$/ ) {
8830 elsif ( $f =~ /^DEFAULT$/i ) {
8831 $value = $DollarCaretP_flags{PERLDB_ALL};
8834 $f =~ /^(?:PERLDBf_)?(.*)$/i;
8835 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
8836 unless ( defined $value ) {
8838 "Unrecognized \$^P flag '$f'!\n",
8839 "Acceptable flags are: "
8840 . join( ', ', sort keys %DollarCaretP_flags ),
8841 ", and hexadecimal and decimal numbers.\n"
8851 sub expand_DollarCaretP_flags {
8852 my $DollarCaretP = shift;
8855 my $n = ( 1 << $_ );
8856 ( $DollarCaretP & $n )
8857 ? ( $DollarCaretP_flags_r{$n}
8858 || sprintf( '0x%x', $n ) )
8862 return @bits ? join( '|', @bits ) : 0;
8869 Rerun the current session to:
8871 rerun current position
8873 rerun 4 command number 4
8875 rerun -4 current command minus 4 (go back 4 steps)
8877 Whether this always makes sense, in the current context is unknowable, and is
8878 in part left as a useful exersize for the reader. This sub returns the
8879 appropriate arguments to rerun the current session.
8886 pop(@truehist); # strim
8887 unless (defined $truehist[$i]) {
8888 print "Unable to return to non-existent command: $i\n";
8890 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
8891 my @temp = @truehist; # store
8892 push(@DB::typeahead, @truehist); # saved
8893 @truehist = @hist = (); # flush
8894 @args = &restart(); # setup
8895 &get_list("PERLDB_HIST"); # clean
8896 &set_list("PERLDB_HIST", @temp); # reset
8903 Restarting the debugger is a complex operation that occurs in several phases.
8904 First, we try to reconstruct the command line that was used to invoke Perl
8910 # I may not be able to resurrect you, but here goes ...
8912 "Warning: some settings and command-line options may be lost!\n";
8913 my ( @script, @flags, $cl );
8915 # If warn was on before, turn it on again.
8916 push @flags, '-w' if $ini_warn;
8918 # Rebuild the -I flags that were on the initial
8921 push @flags, '-I', $_;
8924 # Turn on taint if it was on before.
8925 push @flags, '-T' if ${^TAINT};
8927 # Arrange for setting the old INC:
8928 # Save the current @init_INC in the environment.
8929 set_list( "PERLDB_INC", @ini_INC );
8931 # If this was a perl one-liner, go to the "file"
8932 # corresponding to the one-liner read all the lines
8933 # out of it (except for the first one, which is going
8934 # to be added back on again when 'perl -d' runs: that's
8935 # the 'require perl5db.pl;' line), and add them back on
8936 # to the command line to be executed.
8938 for ( 1 .. $#{'::_<-e'} ) { # The first line is PERL5DB
8939 chomp( $cl = ${'::_<-e'}[$_] );
8940 push @script, '-e', $cl;
8942 } ## end if ($0 eq '-e')
8944 # Otherwise we just reuse the original name we had
8952 After the command line has been reconstructed, the next step is to save
8953 the debugger's status in environment variables. The C<DB::set_list> routine
8954 is used to save aggregate variables (both hashes and arrays); scalars are
8955 just popped into environment variables directly.
8959 # If the terminal supported history, grab it and
8960 # save that in the environment.
8961 set_list( "PERLDB_HIST",
8962 $term->Features->{getHistory}
8966 # Find all the files that were visited during this
8967 # session (i.e., the debugger had magic hashes
8968 # corresponding to them) and stick them in the environment.
8969 my @had_breakpoints = keys %had_breakpoints;
8970 set_list( "PERLDB_VISITED", @had_breakpoints );
8972 # Save the debugger options we chose.
8973 set_list( "PERLDB_OPT", %option );
8974 # set_list( "PERLDB_OPT", options2remember() );
8976 # Save the break-on-loads.
8977 set_list( "PERLDB_ON_LOAD", %break_on_load );
8981 The most complex part of this is the saving of all of the breakpoints. They
8982 can live in an awful lot of places, and we have to go through all of them,
8983 find the breakpoints, and then save them in the appropriate environment
8984 variable via C<DB::set_list>.
8988 # Go through all the breakpoints and make sure they're
8991 for ( 0 .. $#had_breakpoints ) {
8993 # We were in this file.
8994 my $file = $had_breakpoints[$_];
8996 # Grab that file's magic line hash.
8997 *dbline = $main::{ '_<' . $file };
8999 # Skip out if it doesn't exist, or if the breakpoint
9000 # is in a postponed file (we'll do postponed ones
9002 next unless %dbline or $postponed_file{$file};
9004 # In an eval. This is a little harder, so we'll
9005 # do more processing on that below.
9006 ( push @hard, $file ), next
9007 if $file =~ /^\(\w*eval/;
9009 # XXX I have no idea what this is doing. Yet.
9011 @add = %{ $postponed_file{$file} }
9012 if $postponed_file{$file};
9014 # Save the list of all the breakpoints for this file.
9015 set_list( "PERLDB_FILE_$_", %dbline, @add );
9016 } ## end for (0 .. $#had_breakpoints)
9018 # The breakpoint was inside an eval. This is a little
9019 # more difficult. XXX and I don't understand it.
9021 # Get over to the eval in question.
9022 *dbline = $main::{ '_<' . $_ };
9023 my ( $quoted, $sub, %subs, $line ) = quotemeta $_;
9024 for $sub ( keys %sub ) {
9025 next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/;
9026 $subs{$sub} = [ $1, $2 ];
9030 "No subroutines in $_, ignoring breakpoints.\n";
9033 LINES: for $line ( keys %dbline ) {
9035 # One breakpoint per sub only:
9036 my ( $offset, $sub, $found );
9037 SUBS: for $sub ( keys %subs ) {
9040 $line # Not after the subroutine
9042 not defined $offset # Not caught
9048 $offset = $line - $subs{$sub}->[0];
9049 $offset = "+$offset", last SUBS
9051 } ## end if ($subs{$sub}->[1] >=...
9052 } ## end for $sub (keys %subs)
9053 if ( defined $offset ) {
9054 $postponed{$found} =
9055 "break $offset if $dbline{$line}";
9059 "Breakpoint in $_:$line ignored: after all the subroutines.\n";
9061 } ## end for $line (keys %dbline)
9062 } ## end for (@hard)
9064 # Save the other things that don't need to be
9066 set_list( "PERLDB_POSTPONE", %postponed );
9067 set_list( "PERLDB_PRETYPE", @$pretype );
9068 set_list( "PERLDB_PRE", @$pre );
9069 set_list( "PERLDB_POST", @$post );
9070 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9072 # We are oficially restarting.
9073 $ENV{PERLDB_RESTART} = 1;
9075 # We are junking all child debuggers.
9076 delete $ENV{PERLDB_PIDS}; # Restore ini state
9078 # Set this back to the initial pid.
9079 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9083 After all the debugger status has been saved, we take the command we built up
9084 and then return it, so we can C<exec()> it. The debugger will spot the
9085 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9086 from the environment.
9090 # And run Perl again. Add the "-d" flag, all the
9091 # flags we built up, the script (whether a one-liner
9092 # or a file), add on the -emacs flag for a slave editor,
9093 # and then the old arguments.
9095 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9101 =head1 END PROCESSING - THE C<END> BLOCK
9103 Come here at the very end of processing. We want to go into a
9104 loop where we allow the user to enter commands and interact with the
9105 debugger, but we don't want anything else to execute.
9107 First we set the C<$finished> variable, so that some commands that
9108 shouldn't be run after the end of program quit working.
9110 We then figure out whether we're truly done (as in the user entered a C<q>
9111 command, or we finished execution while running nonstop). If we aren't,
9112 we set C<$single> to 1 (causing the debugger to get control again).
9114 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9115 message and returns control to the debugger. Repeat.
9117 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9118 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9119 break, run to completion.).
9124 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9125 $fall_off_end = 1 unless $inhibit_exit;
9127 # Do not stop in at_exit() and destructors on exit:
9128 if ($fall_off_end or $runnonstop) {
9132 DB::fake::at_exit();
9136 =head1 PRE-5.8 COMMANDS
9138 Some of the commands changed function quite a bit in the 5.8 command
9139 realignment, so much so that the old code had to be replaced completely.
9140 Because we wanted to retain the option of being able to go back to the
9141 former command set, we moved the old code off to this section.
9143 There's an awful lot of duplicated code here. We've duplicated the
9144 comments to keep things clear.
9148 Does nothing. Used to I<turn off> commands.
9152 sub cmd_pre580_null {
9157 =head2 Old C<a> command.
9159 This version added actions if you supplied them, and deleted them
9168 # Argument supplied. Add the action.
9169 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9171 # If the line isn't there, use the current line.
9175 # If there is an action ...
9178 # ... but the line isn't breakable, skip it.
9179 if ( $dbline[$i] == 0 ) {
9180 print $OUT "Line $i may not have an action.\n";
9184 # ... and the line is breakable:
9185 # Mark that there's an action in this file.
9186 $had_breakpoints{$filename} |= 2;
9188 # Delete any current action.
9189 $dbline{$i} =~ s/\0[^\0]*//;
9191 # Add the new action, continuing the line as needed.
9192 $dbline{$i} .= "\0" . action($j);
9194 } ## end if (length $j)
9196 # No action supplied.
9199 # Delete the action.
9200 $dbline{$i} =~ s/\0[^\0]*//;
9202 # Mark as having no break or action if nothing's left.
9203 delete $dbline{$i} if $dbline{$i} eq '';
9205 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
9206 } ## end sub cmd_pre580_a
9208 =head2 Old C<b> command
9220 if ( $cmd =~ /^load\b\s*(.*)/ ) {
9226 # b compile|postpone <some sub> [<condition>]
9227 # The interpreter actually traps this one for us; we just put the
9228 # necessary condition in the %postponed hash.
9229 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
9231 # Capture the condition if there is one. Make it true if none.
9232 my $cond = length $3 ? $3 : '1';
9234 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
9235 # if it was 'compile'.
9236 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
9238 # De-Perl4-ify the name - ' separators to ::.
9239 $subname =~ s/\'/::/g;
9241 # Qualify it into the current package unless it's already qualified.
9242 $subname = "${'package'}::" . $subname
9243 unless $subname =~ /::/;
9245 # Add main if it starts with ::.
9246 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
9248 # Save the break type for this sub.
9249 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
9250 } ## end elsif ($cmd =~ ...
9252 # b <sub name> [<condition>]
9253 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
9255 my $cond = length $2 ? $2 : '1';
9256 &cmd_b_sub( $subname, $cond );
9259 # b <line> [<condition>].
9260 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9261 my $i = $1 || $dbline;
9262 my $cond = length $2 ? $2 : '1';
9263 &cmd_b_line( $i, $cond );
9265 } ## end sub cmd_pre580_b
9267 =head2 Old C<D> command.
9269 Delete all breakpoints unconditionally.
9276 if ( $cmd =~ /^\s*$/ ) {
9277 print $OUT "Deleting all breakpoints...\n";
9279 # %had_breakpoints lists every file that had at least one
9282 for $file ( keys %had_breakpoints ) {
9284 # Switch to the desired file temporarily.
9285 local *dbline = $main::{ '_<' . $file };
9290 # For all lines in this file ...
9291 for ( $i = 1 ; $i <= $max ; $i++ ) {
9293 # If there's a breakpoint or action on this line ...
9294 if ( defined $dbline{$i} ) {
9296 # ... remove the breakpoint.
9297 $dbline{$i} =~ s/^[^\0]+//;
9298 if ( $dbline{$i} =~ s/^\0?$// ) {
9300 # Remove the entry altogether if no action is there.
9303 } ## end if (defined $dbline{$i...
9304 } ## end for ($i = 1 ; $i <= $max...
9306 # If, after we turn off the "there were breakpoints in this file"
9307 # bit, the entry in %had_breakpoints for this file is zero,
9308 # we should remove this file from the hash.
9309 if ( not $had_breakpoints{$file} &= ~1 ) {
9310 delete $had_breakpoints{$file};
9312 } ## end for $file (keys %had_breakpoints)
9314 # Kill off all the other breakpoints that are waiting for files that
9315 # haven't been loaded yet.
9317 undef %postponed_file;
9318 undef %break_on_load;
9319 } ## end if ($cmd =~ /^\s*$/)
9320 } ## end sub cmd_pre580_D
9322 =head2 Old C<h> command
9324 Print help. Defaults to printing the long-form help; the 5.8 version
9325 prints the summary by default.
9333 # Print the *right* help, long format.
9334 if ( $cmd =~ /^\s*$/ ) {
9335 print_help($pre580_help);
9338 # 'h h' - explicitly-requested summary.
9339 elsif ( $cmd =~ /^h\s*/ ) {
9340 print_help($pre580_summary);
9343 # Find and print a command's help.
9344 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
9345 my $asked = $1; # for proper errmsg
9346 my $qasked = quotemeta($asked); # for searching
9347 # XXX: finds CR but not <CR>
9351 (?:[IB]<) # Optional markup
9352 $qasked # The command name
9359 ( # The command help:
9361 (?:[IB]<) # Optional markup
9362 $qasked # The command name
9363 ([\s\S]*?) # Lines starting with tabs
9367 ) # Line not starting with space
9368 # (Next command's help)
9372 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
9376 print_help("B<$asked> is not a debugger command.\n");
9378 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
9379 } ## end sub cmd_pre580_h
9381 =head2 Old C<W> command
9383 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
9391 # Delete all watch expressions.
9392 if ( $cmd =~ /^$/ ) {
9394 # No watching is going on.
9397 # Kill all the watch expressions and values.
9398 @to_watch = @old_watch = ();
9401 # Add a watch expression.
9402 elsif ( $cmd =~ /^(.*)/s ) {
9404 # add it to the list to be watched.
9407 # Get the current value of the expression.
9408 # Doesn't handle expressions returning list values!
9411 $val = ( defined $val ) ? "'$val'" : 'undef';
9414 push @old_watch, $val;
9416 # We're watching stuff.
9419 } ## end elsif ($cmd =~ /^(.*)/s)
9420 } ## end sub cmd_pre580_W
9422 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
9424 The debugger used to have a bunch of nearly-identical code to handle
9425 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
9426 C<cmd_prepost> unify all this into one set of code to handle the
9427 appropriate actions.
9429 =head2 C<cmd_pre590_prepost>
9431 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
9432 do something destructive. In pre 5.8 debuggers, the default action was to
9433 delete all the actions.
9437 sub cmd_pre590_prepost {
9439 my $line = shift || '*';
9442 return &cmd_prepost( $cmd, $line, $dbline );
9443 } ## end sub cmd_pre590_prepost
9445 =head2 C<cmd_prepost>
9447 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
9448 Since the lists of actions are all held in arrays that are pointed to by
9449 references anyway, all we have to do is pick the right array reference and
9450 then use generic code to all, delete, or list actions.
9457 # No action supplied defaults to 'list'.
9458 my $line = shift || '?';
9460 # Figure out what to put in the prompt.
9463 # Make sure we have some array or another to address later.
9464 # This means that if ssome reason the tests fail, we won't be
9465 # trying to stash actions or delete them from the wrong place.
9468 # < - Perl code to run before prompt.
9469 if ( $cmd =~ /^\</o ) {
9470 $which = 'pre-perl';
9474 # > - Perl code to run after prompt.
9475 elsif ( $cmd =~ /^\>/o ) {
9476 $which = 'post-perl';
9480 # { - first check for properly-balanced braces.
9481 elsif ( $cmd =~ /^\{/o ) {
9482 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
9484 "$cmd is now a debugger command\nuse `;$cmd' if you mean Perl code\n";
9487 # Properly balanced. Pre-prompt debugger actions.
9489 $which = 'pre-debugger';
9492 } ## end elsif ( $cmd =~ /^\{/o )
9494 # Did we find something that makes sense?
9496 print $OUT "Confused by command: $cmd\n";
9503 if ( $line =~ /^\s*\?\s*$/o ) {
9506 # Nothing there. Complain.
9507 print $OUT "No $which actions.\n";
9511 # List the actions in the selected list.
9512 print $OUT "$which commands:\n";
9513 foreach my $action (@$aref) {
9514 print $OUT "\t$cmd -- $action\n";
9517 } ## end if ( $line =~ /^\s*\?\s*$/o)
9519 # Might be a delete.
9521 if ( length($cmd) == 1 ) {
9522 if ( $line =~ /^\s*\*\s*$/o ) {
9524 # It's a delete. Get rid of the old actions in the
9527 print $OUT "All $cmd actions cleared.\n";
9531 # Replace all the actions. (This is a <, >, or {).
9532 @$aref = action($line);
9534 } ## end if ( length($cmd) == 1)
9535 elsif ( length($cmd) == 2 ) {
9537 # Add the action to the line. (This is a <<, >>, or {{).
9538 push @$aref, action($line);
9542 # <<<, >>>>, {{{{{{ ... something not a command.
9544 "Confused by strange length of $which command($cmd)...\n";
9546 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
9548 } ## end sub cmd_prepost
9552 Contains the C<at_exit> routine that the debugger uses to issue the
9553 C<Debugged program terminated ...> message after the program completes. See
9554 the C<END> block documentation for more details.
9561 "Debugged program terminated. Use `q' to quit or `R' to restart.";
9564 package DB; # Do not trace this 1; below!
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