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.
244 &parse_options("NonStop=1 LineInfo=db.out");
245 sub afterinit { $trace = 1; }
247 The script will run without human intervention, putting trace
248 information into C<db.out>. (If you interrupt it, you had better
249 reset C<LineInfo> to something I<interactive>!)
251 =head1 INTERNALS DESCRIPTION
253 =head2 DEBUGGER INTERFACE VARIABLES
255 Perl supplies the values for C<%sub>. It effectively inserts
256 a C<&DB::DB();> in front of each place that can have a
257 breakpoint. At each subroutine call, it calls C<&DB::sub> with
258 C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
259 {require 'perl5db.pl'}> before the first line.
261 After each C<require>d file is compiled, but before it is executed, a
262 call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
263 is the expanded name of the C<require>d file (as found via C<%INC>).
265 =head3 IMPORTANT INTERNAL VARIABLES
269 Used to control when the debugger will attempt to acquire another TTY to be
274 =item * 1 - on C<fork()>
276 =item * 2 - debugger is started inside debugger
278 =item * 4 - on startup
284 The value -2 indicates that no return value should be printed.
285 Any other positive value causes C<DB::sub> to print return values.
289 The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
290 contents of C<@_> when C<DB::eval> is called.
294 Determines what messages (if any) will get printed when a subroutine (or eval)
295 is entered or exited.
299 =item * 0 - No enter/exit messages
301 =item * 1 - Print I<entering> messages on subroutine entry
303 =item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
305 =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.
307 =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.
309 =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.
313 To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
314 The debugger internally juggles the value of C<$frame> during execution to
315 protect external modules that the debugger uses from getting traced.
319 Tracks current debugger nesting level. Used to figure out how many
320 C<E<lt>E<gt>> pairs to surround the line number with when the debugger
321 outputs a prompt. Also used to help determine if the program has finished
322 during command parsing.
324 =head4 C<$onetimeDump>
326 Controls what (if anything) C<DB::eval()> will print after evaluating an
331 =item * C<undef> - don't print anything
333 =item * C<dump> - use C<dumpvar.pl> to display the value returned
335 =item * C<methods> - print the methods callable on the first item returned
339 =head4 C<$onetimeDumpDepth>
341 Controls how far down C<dumpvar.pl> will go before printing C<...> while
342 dumping a structure. Numeric. If C<undef>, print all levels.
346 Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
347 which is called before every statement, checks this and puts the user into
348 command mode if it finds C<$signal> set to a true value.
352 Controls behavior during single-stepping. Stacked in C<@stack> on entry to
353 each subroutine; popped again at the end of each subroutine.
357 =item * 0 - run continuously.
359 =item * 1 - single-step, go into subs. The C<s> command.
361 =item * 2 - single-step, don't go into subs. The C<n> command.
363 =item * 4 - print current sub depth (turned on to force this when C<too much
370 Controls the output of trace information.
374 =item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
376 =item * 2 - watch expressions are active
378 =item * 4 - user defined a C<watchfunction()> in C<afterinit()>
382 =head4 C<$slave_editor>
384 1 if C<LINEINFO> was directed to a pipe; 0 otherwise.
388 Stack of filehandles that C<DB::readline()> will read commands from.
389 Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
393 Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
394 supplied by the Perl interpreter to the debugger. Contains the source.
398 Previous values of watch expressions. First set when the expression is
399 entered; reset whenever the watch expression changes.
403 Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
404 so that the debugger can substitute safe values while it's running, and
405 restore them when it returns control.
409 Saves the current value of C<$single> on entry to a subroutine.
410 Manipulated by the C<c> command to turn off tracing in all subs above the
415 The 'watch' expressions: to be evaluated before each line is executed.
419 The typeahead buffer, used by C<DB::readline>.
423 Command aliases. Stored as character strings to be substituted for a command
426 =head4 C<%break_on_load>
428 Keys are file names, values are 1 (break when this file is loaded) or undef
429 (don't break when it is loaded).
433 Keys are line numbers, values are C<condition\0action>. If used in numeric
434 context, values are 0 if not breakable, 1 if breakable, no matter what is
435 in the actual hash entry.
437 =head4 C<%had_breakpoints>
439 Keys are file names; values are bitfields:
443 =item * 1 - file has a breakpoint in it.
445 =item * 2 - file has an action in it.
449 A zero or undefined value means this file has neither.
453 Stores the debugger options. These are character string values.
457 Saves breakpoints for code that hasn't been compiled yet.
458 Keys are subroutine names, values are:
462 =item * C<compile> - break when this sub is compiled
464 =item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
468 =head4 C<%postponed_file>
470 This hash keeps track of breakpoints that need to be set for files that have
471 not yet been compiled. Keys are filenames; values are references to hashes.
472 Each of these hashes is keyed by line number, and its values are breakpoint
473 definitions (C<condition\0action>).
475 =head1 DEBUGGER INITIALIZATION
477 The debugger's initialization actually jumps all over the place inside this
478 package. This is because there are several BEGIN blocks (which of course
479 execute immediately) spread through the code. Why is that?
481 The debugger needs to be able to change some things and set some things up
482 before the debugger code is compiled; most notably, the C<$deep> variable that
483 C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
484 debugger has to turn off warnings while the debugger code is compiled, but then
485 restore them to their original setting before the program being debugged begins
488 The first C<BEGIN> block simply turns off warnings by saving the current
489 setting of C<$^W> and then setting it to zero. The second one initializes
490 the debugger variables that are needed before the debugger begins executing.
491 The third one puts C<$^X> back to its former value.
493 We'll detail the second C<BEGIN> block later; just remember that if you need
494 to initialize something before the debugger starts really executing, that's
501 BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
503 # Debugger for Perl 5.00x; perl5db.pl patch level:
506 $header = "perl5db.pl version $VERSION";
508 =head1 DEBUGGER ROUTINES
512 This function replaces straight C<eval()> inside the debugger; it simplifies
513 the process of evaluating code in the user's context.
515 The code to be evaluated is passed via the package global variable
516 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
518 Before we do the C<eval()>, we preserve the current settings of C<$trace>,
519 C<$single>, C<$^D> and C<$usercontext>. The latter contains the
520 preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
521 user's current package, grabbed when C<DB::DB> got control. This causes the
522 proper context to be used when the eval is actually done. Afterward, we
523 restore C<$trace>, C<$single>, and C<$^D>.
525 Next we need to handle C<$@> without getting confused. We save C<$@> in a
526 local lexical, localize C<$saved[0]> (which is where C<save()> will put
527 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
528 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
529 considered sane by the debugger. If there was an C<eval()> error, we print
530 it on the debugger's output. If C<$onetimedump> is defined, we call
531 C<dumpit> if it's set to 'dump', or C<methods> if it's set to
532 'methods'. Setting it to something else causes the debugger to do the eval
533 but not print the result - handy if you want to do something else with it
534 (the "watch expressions" code does this to get the value of the watch
535 expression but not show it unless it matters).
537 In any case, we then return the list of output from C<eval> to the caller,
538 and unwinding restores the former version of C<$@> in C<@saved> as well
539 (the localization of C<$saved[0]> goes away at the end of this scope).
541 =head3 Parameters and variables influencing execution of DB::eval()
543 C<DB::eval> isn't parameterized in the standard way; this is to keep the
544 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
545 The variables listed below influence C<DB::eval()>'s execution directly.
549 =item C<$evalarg> - the thing to actually be eval'ed
551 =item C<$trace> - Current state of execution tracing
553 =item C<$single> - Current state of single-stepping
555 =item C<$onetimeDump> - what is to be displayed after the evaluation
557 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
561 The following variables are altered by C<DB::eval()> during its execution. They
562 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
566 =item C<@res> - used to capture output from actual C<eval>.
568 =item C<$otrace> - saved value of C<$trace>.
570 =item C<$osingle> - saved value of C<$single>.
572 =item C<$od> - saved value of C<$^D>.
574 =item C<$saved[0]> - saved value of C<$@>.
576 =item $\ - for output of C<$@> if there is an evaluation error.
580 =head3 The problem of lexicals
582 The context of C<DB::eval()> presents us with some problems. Obviously,
583 we want to be 'sandboxed' away from the debugger's internals when we do
584 the eval, but we need some way to control how punctuation variables and
585 debugger globals are used.
587 We can't use local, because the code inside C<DB::eval> can see localized
588 variables; and we can't use C<my> either for the same reason. The code
589 in this routine compromises and uses C<my>.
591 After this routine is over, we don't have user code executing in the debugger's
592 context, so we can use C<my> freely.
596 ############################################## Begin lexical danger zone
598 # 'my' variables used here could leak into (that is, be visible in)
599 # the context that the code being evaluated is executing in. This means that
600 # the code could modify the debugger's variables.
602 # Fiddling with the debugger's context could be Bad. We insulate things as
607 # 'my' would make it visible from user code
608 # but so does local! --tchrist
609 # Remember: this localizes @DB::res, not @main::res.
613 # Try to keep the user code from messing with us. Save these so that
614 # even if the eval'ed code changes them, we can put them back again.
615 # Needed because the user could refer directly to the debugger's
616 # package globals (and any 'my' variables in this containing scope)
617 # inside the eval(), and we want to try to stay safe.
618 local $otrace = $trace;
619 local $osingle = $single;
622 # Untaint the incoming eval() argument.
623 { ($evalarg) = $evalarg =~ /(.*)/s; }
625 # $usercontext built in DB::DB near the comment
626 # "set up the context for DB::eval ..."
627 # Evaluate and save any results.
628 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
630 # Restore those old values.
636 # Save the current value of $@, and preserve it in the debugger's copy
637 # of the saved precious globals.
640 # Since we're only saving $@, we only have to localize the array element
641 # that it will be stored in.
642 local $saved[0]; # Preserve the old value of $@
645 # Now see whether we need to report an error back to the user.
651 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
652 # are package globals.
653 elsif ($onetimeDump) {
654 if ( $onetimeDump eq 'dump' ) {
655 local $option{dumpDepth} = $onetimedumpDepth
656 if defined $onetimedumpDepth;
657 dumpit( $OUT, \@res );
659 elsif ( $onetimeDump eq 'methods' ) {
662 } ## end elsif ($onetimeDump)
666 ############################################## End lexical danger zone
668 # After this point it is safe to introduce lexicals.
669 # The code being debugged will be executing in its own context, and
670 # can't see the inside of the debugger.
672 # However, one should not overdo it: leave as much control from outside as
673 # possible. If you make something a lexical, it's not going to be addressable
674 # from outside the debugger even if you know its name.
676 # This file is automatically included if you do perl -d.
677 # It's probably not useful to include this yourself.
679 # Before venturing further into these twisty passages, it is
680 # wise to read the perldebguts man page or risk the ire of dragons.
682 # (It should be noted that perldebguts will tell you a lot about
683 # the underlying mechanics of how the debugger interfaces into the
684 # Perl interpreter, but not a lot about the debugger itself. The new
685 # comments in this code try to address this problem.)
687 # Note that no subroutine call is possible until &DB::sub is defined
688 # (for subroutines defined outside of the package DB). In fact the same is
689 # true if $deep is not defined.
691 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
693 # modified Perl debugger, to be run from Emacs in perldb-mode
694 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
695 # Johan Vromans -- upgrade to 4.0 pl 10
696 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
698 # (We have made efforts to clarify the comments in the change log
699 # in other places; some of them may seem somewhat obscure as they
700 # were originally written, and explaining them away from the code
701 # in question seems conterproductive.. -JM)
703 ########################################################################
705 # + A lot of things changed after 0.94. First of all, core now informs
706 # debugger about entry into XSUBs, overloaded operators, tied operations,
707 # BEGIN and END. Handy with `O f=2'.
708 # + This can make debugger a little bit too verbose, please be patient
709 # and report your problems promptly.
710 # + Now the option frame has 3 values: 0,1,2. XXX Document!
711 # + Note that if DESTROY returns a reference to the object (or object),
712 # the deletion of data may be postponed until the next function call,
713 # due to the need to examine the return value.
716 # + `v' command shows versions.
719 # + `v' command shows version of readline.
720 # primitive completion works (dynamic variables, subs for `b' and `l',
721 # options). Can `p %var'
722 # + Better help (`h <' now works). New commands <<, >>, {, {{.
723 # {dump|print}_trace() coded (to be able to do it from <<cmd).
724 # + `c sub' documented.
725 # + At last enough magic combined to stop after the end of debuggee.
726 # + !! should work now (thanks to Emacs bracket matching an extra
727 # `]' in a regexp is caught).
728 # + `L', `D' and `A' span files now (as documented).
729 # + Breakpoints in `require'd code are possible (used in `R').
730 # + Some additional words on internal work of debugger.
731 # + `b load filename' implemented.
732 # + `b postpone subr' implemented.
733 # + now only `q' exits debugger (overwritable on $inhibit_exit).
734 # + When restarting debugger breakpoints/actions persist.
735 # + Buglet: When restarting debugger only one breakpoint/action per
736 # autoloaded function persists.
738 # Changes: 0.97: NonStop will not stop in at_exit().
739 # + Option AutoTrace implemented.
740 # + Trace printed differently if frames are printed too.
741 # + new `inhibitExit' option.
742 # + printing of a very long statement interruptible.
743 # Changes: 0.98: New command `m' for printing possible methods
744 # + 'l -' is a synonym for `-'.
745 # + Cosmetic bugs in printing stack trace.
746 # + `frame' & 8 to print "expanded args" in stack trace.
747 # + Can list/break in imported subs.
748 # + new `maxTraceLen' option.
749 # + frame & 4 and frame & 8 granted.
751 # + nonstoppable lines do not have `:' near the line number.
752 # + `b compile subname' implemented.
753 # + Will not use $` any more.
754 # + `-' behaves sane now.
755 # Changes: 0.99: Completion for `f', `m'.
756 # + `m' will remove duplicate names instead of duplicate functions.
757 # + `b load' strips trailing whitespace.
758 # completion ignores leading `|'; takes into account current package
759 # when completing a subroutine name (same for `l').
760 # Changes: 1.07: Many fixed by tchrist 13-March-2000
762 # + Added bare minimal security checks on perldb rc files, plus
763 # comments on what else is needed.
764 # + Fixed the ornaments that made "|h" completely unusable.
765 # They are not used in print_help if they will hurt. Strip pod
766 # if we're paging to less.
767 # + Fixed mis-formatting of help messages caused by ornaments
768 # to restore Larry's original formatting.
769 # + Fixed many other formatting errors. The code is still suboptimal,
770 # and needs a lot of work at restructuring. It's also misindented
772 # + Fixed bug where trying to look at an option like your pager
774 # + Fixed some $? processing. Note: if you use csh or tcsh, you will
775 # lose. You should consider shell escapes not using their shell,
776 # or else not caring about detailed status. This should really be
777 # unified into one place, too.
778 # + Fixed bug where invisible trailing whitespace on commands hoses you,
779 # tricking Perl into thinking you weren't calling a debugger command!
780 # + Fixed bug where leading whitespace on commands hoses you. (One
781 # suggests a leading semicolon or any other irrelevant non-whitespace
782 # to indicate literal Perl code.)
783 # + Fixed bugs that ate warnings due to wrong selected handle.
784 # + Fixed a precedence bug on signal stuff.
785 # + Fixed some unseemly wording.
786 # + Fixed bug in help command trying to call perl method code.
787 # + Fixed to call dumpvar from exception handler. SIGPIPE killed us.
789 # + Added some comments. This code is still nasty spaghetti.
790 # + Added message if you clear your pre/post command stacks which was
791 # very easy to do if you just typed a bare >, <, or {. (A command
792 # without an argument should *never* be a destructive action; this
793 # API is fundamentally screwed up; likewise option setting, which
794 # is equally buggered.)
795 # + Added command stack dump on argument of "?" for >, <, or {.
796 # + Added a semi-built-in doc viewer command that calls man with the
797 # proper %Config::Config path (and thus gets caching, man -k, etc),
798 # or else perldoc on obstreperous platforms.
799 # + Added to and rearranged the help information.
800 # + Detected apparent misuse of { ... } to declare a block; this used
801 # to work but now is a command, and mysteriously gave no complaint.
803 # Changes: 1.08: Apr 25, 2001 Jon Eveland <jweveland@yahoo.com>
805 # + This patch to perl5db.pl cleans up formatting issues on the help
806 # summary (h h) screen in the debugger. Mostly columnar alignment
807 # issues, plus converted the printed text to use all spaces, since
808 # tabs don't seem to help much here.
810 # Changes: 1.09: May 19, 2001 Ilya Zakharevich <ilya@math.ohio-state.edu>
811 # Minor bugs corrected;
812 # + Support for auto-creation of new TTY window on startup, either
813 # unconditionally, or if started as a kid of another debugger session;
814 # + New `O'ption CreateTTY
815 # I<CreateTTY> bits control attempts to create a new TTY on events:
817 # 2: debugger is started inside debugger
819 # + Code to auto-create a new TTY window on OS/2 (currently one
820 # extra window per session - need named pipes to have more...);
821 # + Simplified interface for custom createTTY functions (with a backward
822 # compatibility hack); now returns the TTY name to use; return of ''
823 # means that the function reset the I/O handles itself;
824 # + Better message on the semantic of custom createTTY function;
825 # + Convert the existing code to create a TTY into a custom createTTY
827 # + Consistent support for TTY names of the form "TTYin,TTYout";
828 # + Switch line-tracing output too to the created TTY window;
829 # + make `b fork' DWIM with CORE::GLOBAL::fork;
830 # + High-level debugger API cmd_*():
831 # cmd_b_load($filenamepart) # b load filenamepart
832 # cmd_b_line($lineno [, $cond]) # b lineno [cond]
833 # cmd_b_sub($sub [, $cond]) # b sub [cond]
834 # cmd_stop() # Control-C
835 # cmd_d($lineno) # d lineno (B)
836 # The cmd_*() API returns FALSE on failure; in this case it outputs
837 # the error message to the debugging output.
838 # + Low-level debugger API
839 # break_on_load($filename) # b load filename
840 # @files = report_break_on_load() # List files with load-breakpoints
841 # breakable_line_in_filename($name, $from [, $to])
842 # # First breakable line in the
843 # # range $from .. $to. $to defaults
844 # # to $from, and may be less than
846 # breakable_line($from [, $to]) # Same for the current file
847 # break_on_filename_line($name, $lineno [, $cond])
848 # # Set breakpoint,$cond defaults to
850 # break_on_filename_line_range($name, $from, $to [, $cond])
851 # # As above, on the first
852 # # breakable line in range
853 # break_on_line($lineno [, $cond]) # As above, in the current file
854 # break_subroutine($sub [, $cond]) # break on the first breakable line
855 # ($name, $from, $to) = subroutine_filename_lines($sub)
856 # # The range of lines of the text
857 # The low-level API returns TRUE on success, and die()s on failure.
859 # Changes: 1.10: May 23, 2001 Daniel Lewart <d-lewart@uiuc.edu>
861 # + Fixed warnings generated by "perl -dWe 42"
862 # + Corrected spelling errors
863 # + Squeezed Help (h) output into 80 columns
865 # Changes: 1.11: May 24, 2001 David Dyck <dcd@tc.fluke.com>
866 # + Made "x @INC" work like it used to
868 # Changes: 1.12: May 24, 2001 Daniel Lewart <d-lewart@uiuc.edu>
869 # + Fixed warnings generated by "O" (Show debugger options)
870 # + Fixed warnings generated by "p 42" (Print expression)
871 # Changes: 1.13: Jun 19, 2001 Scott.L.Miller@compaq.com
872 # + Added windowSize option
873 # Changes: 1.14: Oct 9, 2001 multiple
874 # + Clean up after itself on VMS (Charles Lane in 12385)
875 # + Adding "@ file" syntax (Peter Scott in 12014)
876 # + Debug reloading selfloaded stuff (Ilya Zakharevich in 11457)
877 # + $^S and other debugger fixes (Ilya Zakharevich in 11120)
878 # + Forgot a my() declaration (Ilya Zakharevich in 11085)
879 # Changes: 1.15: Nov 6, 2001 Michael G Schwern <schwern@pobox.com>
880 # + Updated 1.14 change log
881 # + Added *dbline explainatory comments
882 # + Mentioning perldebguts man page
883 # Changes: 1.16: Feb 15, 2002 Mark-Jason Dominus <mjd@plover.com>
884 # + $onetimeDump improvements
885 # Changes: 1.17: Feb 20, 2002 Richard Foley <richard.foley@rfi.net>
886 # Moved some code to cmd_[.]()'s for clarity and ease of handling,
887 # rationalised the following commands and added cmd_wrapper() to
888 # enable switching between old and frighteningly consistent new
889 # behaviours for diehards: 'o CommandSet=pre580' (sigh...)
890 # a(add), A(del) # action expr (added del by line)
891 # + b(add), B(del) # break [line] (was b,D)
892 # + w(add), W(del) # watch expr (was W,W)
893 # # added del by expr
894 # + h(summary), h h(long) # help (hh) (was h h,h)
895 # + m(methods), M(modules) # ... (was m,v)
896 # + o(option) # lc (was O)
897 # + v(view code), V(view Variables) # ... (was w,V)
898 # Changes: 1.18: Mar 17, 2002 Richard Foley <richard.foley@rfi.net>
899 # + fixed missing cmd_O bug
900 # Changes: 1.19: Mar 29, 2002 Spider Boardman
901 # + Added missing local()s -- DB::DB is called recursively.
902 # Changes: 1.20: Feb 17, 2003 Richard Foley <richard.foley@rfi.net>
903 # + pre'n'post commands no longer trashed with no args
904 # + watch val joined out of eval()
905 # Changes: 1.21: Jun 04, 2003 Joe McMahon <mcmahon@ibiblio.org>
906 # + Added comments and reformatted source. No bug fixes/enhancements.
907 # + Includes cleanup by Robin Barker and Jarkko Hietaniemi.
908 # Changes: 1.22 Jun 09, 2003 Alex Vandiver <alexmv@MIT.EDU>
909 # + Flush stdout/stderr before the debugger prompt is printed.
910 # Changes: 1.23: Dec 21, 2003 Dominique Quatravaux
911 # + Fix a side-effect of bug #24674 in the perl debugger ("odd taint bug")
912 # Changes: 1.24: Mar 03, 2004 Richard Foley <richard.foley@rfi.net>
913 # + Added command to save all debugger commands for sourcing later.
914 # + Added command to display parent inheritance tree of given class.
915 # + Fixed minor newline in history bug.
916 # Changes: 1.25: Apr 17, 2004 Richard Foley <richard.foley@rfi.net>
917 # + Fixed option bug (setting invalid options + not recognising valid short forms)
918 # Changes: 1.26: Apr 22, 2004 Richard Foley <richard.foley@rfi.net>
919 # + unfork the 5.8.x and 5.9.x debuggers.
920 # + whitespace and assertions call cleanup across versions
921 # + H * deletes (resets) history
922 # + i now handles Class + blessed objects
923 # Changes: 1.27: May 09, 2004 Richard Foley <richard.foley@rfi.net>
924 # + updated pod page references - clunky.
925 # + removed windowid restriction for forking into an xterm.
926 # + more whitespace again.
927 # + wrapped restart and enabled rerun [-n] (go back n steps) command.
928 # Changes: 1.28: Oct 12, 2004 Richard Foley <richard.foley@rfi.net>
929 # + Added threads support (inc. e and E commands)
930 # Changes: 1.29: Nov 28, 2006 Bo Lindbergh <blgl@hagernas.com>
931 # + Added macosx_get_fork_TTY support
932 ########################################################################
934 =head1 DEBUGGER INITIALIZATION
936 The debugger starts up in phases.
940 First, it initializes the environment it wants to run in: turning off
941 warnings during its own compilation, defining variables which it will need
942 to avoid warnings later, setting itself up to not exit when the program
943 terminates, and defaulting to printing return values for the C<r> command.
947 # Needed for the statement after exec():
949 # This BEGIN block is simply used to switch off warnings during debugger
950 # compiliation. Probably it would be better practice to fix the warnings,
951 # but this is how it's done at the moment.
956 } # Switch compilation warnings off until another BEGIN.
958 # test if assertions are supported and actived:
960 $ini_assertion = eval "sub asserting_test : assertion {1}; 1";
962 # $ini_assertion = undef => assertions unsupported,
963 # " = 1 => assertions supported
964 # print "\$ini_assertion=$ini_assertion\n";
967 local ($^W) = 0; # Switch run-time warnings off during init.
969 =head2 THREADS SUPPORT
971 If we are running under a threaded Perl, we require threads and threads::shared
972 if the environment variable C<PERL5DB_THREADED> is set, to enable proper
973 threaded debugger control. C<-dt> can also be used to set this.
975 Each new thread will be announced and the debugger prompt will always inform
976 you of each new thread created. It will also indicate the thread id in which
977 we are currently running within the prompt like this:
981 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
982 command prompt. The prompt will show: C<[0]> when running under threads, but
983 not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
985 While running under threads, when you set or delete a breakpoint (etc.), this
986 will apply to all threads, not just the currently running one. When you are
987 in a currently executing thread, you will stay there until it completes. With
988 the current implementation it is not currently possible to hop from one thread
991 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
993 Note that threading support was built into the debugger as of Perl version
994 C<5.8.6> and debugger version C<1.2.8>.
999 # ensure we can share our non-threaded variables or no-op
1000 if ($ENV{PERL5DB_THREADED}) {
1002 require threads::shared;
1003 import threads::shared qw(share);
1007 print "Threads support enabled\n";
1014 # This would probably be better done with "use vars", but that wasn't around
1015 # when this code was originally written. (Neither was "use strict".) And on
1016 # the principle of not fiddling with something that was working, this was
1019 # These variables control the execution of 'dumpvar.pl'.
1020 $dumpvar::hashDepth,
1021 $dumpvar::arrayDepth,
1022 $dumpvar::dumpDBFiles,
1023 $dumpvar::dumpPackages,
1024 $dumpvar::quoteHighBit,
1025 $dumpvar::printUndef,
1026 $dumpvar::globPrint,
1027 $dumpvar::usageOnly,
1029 # used to save @ARGV and extract any debugger-related flags.
1032 # used to control die() reporting in diesignal()
1035 # used to prevent multiple entries to diesignal()
1036 # (if for instance diesignal() itself dies)
1039 # used to prevent the debugger from running nonstop
1045 foreach my $k (keys (%INC)) {
1046 &share(\$main::{'_<'.$filename});
1049 # Command-line + PERLLIB:
1050 # Save the contents of @INC before they are modified elsewhere.
1053 # This was an attempt to clear out the previous values of various
1054 # trapped errors. Apparently it didn't help. XXX More info needed!
1055 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
1057 # We set these variables to safe values. We don't want to blindly turn
1058 # off warnings, because other packages may still want them.
1059 $trace = $signal = $single = 0; # Uninitialized warning suppression
1060 # (local $^W cannot help - other packages!).
1062 # Default to not exiting when program finishes; print the return
1063 # value when the 'r' command is used to return from a subroutine.
1064 $inhibit_exit = $option{PrintRet} = 1;
1066 =head1 OPTION PROCESSING
1068 The debugger's options are actually spread out over the debugger itself and
1069 C<dumpvar.pl>; some of these are variables to be set, while others are
1070 subs to be called with a value. To try to make this a little easier to
1071 manage, the debugger uses a few data structures to define what options
1072 are legal and how they are to be processed.
1074 First, the C<@options> array defines the I<names> of all the options that
1081 hashDepth arrayDepth dumpDepth
1082 DumpDBFiles DumpPackages DumpReused
1083 compactDump veryCompact quote
1084 HighBit undefPrint globPrint
1085 PrintRet UsageOnly frame
1087 ReadLine NonStop LineInfo
1088 maxTraceLen recallCommand ShellBang
1089 pager tkRunning ornaments
1090 signalLevel warnLevel dieLevel
1091 inhibit_exit ImmediateStop bareStringify
1092 CreateTTY RemotePort windowSize
1093 DollarCaretP OnlyAssertions WarnAssertions
1096 @RememberOnROptions = qw(DollarCaretP OnlyAssertions);
1100 Second, C<optionVars> lists the variables that each option uses to save its
1106 hashDepth => \$dumpvar::hashDepth,
1107 arrayDepth => \$dumpvar::arrayDepth,
1108 CommandSet => \$CommandSet,
1109 DumpDBFiles => \$dumpvar::dumpDBFiles,
1110 DumpPackages => \$dumpvar::dumpPackages,
1111 DumpReused => \$dumpvar::dumpReused,
1112 HighBit => \$dumpvar::quoteHighBit,
1113 undefPrint => \$dumpvar::printUndef,
1114 globPrint => \$dumpvar::globPrint,
1115 UsageOnly => \$dumpvar::usageOnly,
1116 CreateTTY => \$CreateTTY,
1117 bareStringify => \$dumpvar::bareStringify,
1119 AutoTrace => \$trace,
1120 inhibit_exit => \$inhibit_exit,
1121 maxTraceLen => \$maxtrace,
1122 ImmediateStop => \$ImmediateStop,
1123 RemotePort => \$remoteport,
1124 windowSize => \$window,
1125 WarnAssertions => \$warnassertions,
1130 Third, C<%optionAction> defines the subroutine to be called to process each
1136 compactDump => \&dumpvar::compactDump,
1137 veryCompact => \&dumpvar::veryCompact,
1138 quote => \&dumpvar::quote,
1141 ReadLine => \&ReadLine,
1142 NonStop => \&NonStop,
1143 LineInfo => \&LineInfo,
1144 recallCommand => \&recallCommand,
1145 ShellBang => \&shellBang,
1147 signalLevel => \&signalLevel,
1148 warnLevel => \&warnLevel,
1149 dieLevel => \&dieLevel,
1150 tkRunning => \&tkRunning,
1151 ornaments => \&ornaments,
1152 RemotePort => \&RemotePort,
1153 DollarCaretP => \&DollarCaretP,
1154 OnlyAssertions=> \&OnlyAssertions,
1159 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1164 # Note that this list is not complete: several options not listed here
1165 # actually require that dumpvar.pl be loaded for them to work, but are
1166 # not in the table. A subsequent patch will correct this problem; for
1167 # the moment, we're just recommenting, and we are NOT going to change
1170 compactDump => 'dumpvar.pl',
1171 veryCompact => 'dumpvar.pl',
1172 quote => 'dumpvar.pl',
1177 There are a number of initialization-related variables which can be set
1178 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1179 variable. These are:
1183 =item C<$rl> - readline control XXX needs more explanation
1185 =item C<$warnLevel> - whether or not debugger takes over warning handling
1187 =item C<$dieLevel> - whether or not debugger takes over die handling
1189 =item C<$signalLevel> - whether or not debugger takes over signal handling
1191 =item C<$pre> - preprompt actions (array reference)
1193 =item C<$post> - postprompt actions (array reference)
1197 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1199 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1205 # These guys may be defined in $ENV{PERL5DB} :
1206 $rl = 1 unless defined $rl;
1207 $warnLevel = 1 unless defined $warnLevel;
1208 $dieLevel = 1 unless defined $dieLevel;
1209 $signalLevel = 1 unless defined $signalLevel;
1210 $pre = [] unless defined $pre;
1211 $post = [] unless defined $post;
1212 $pretype = [] unless defined $pretype;
1213 $CreateTTY = 3 unless defined $CreateTTY;
1214 $CommandSet = '580' unless defined $CommandSet;
1219 share($signalLevel);
1229 The default C<die>, C<warn>, and C<signal> handlers are set up.
1233 warnLevel($warnLevel);
1234 dieLevel($dieLevel);
1235 signalLevel($signalLevel);
1239 The pager to be used is needed next. We try to get it from the
1240 environment first. if it's not defined there, we try to find it in
1241 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1242 then call the C<pager()> function to save the pager name.
1246 # This routine makes sure $pager is set up so that '|' can use it.
1249 # If PAGER is defined in the environment, use it.
1253 # If not, see if Config.pm defines it.
1254 : eval { require Config }
1255 && defined $Config::Config{pager}
1256 ? $Config::Config{pager}
1258 # If not, fall back to 'more'.
1261 unless defined $pager;
1265 We set up the command to be used to access the man pages, the command
1266 recall character (C<!> unless otherwise defined) and the shell escape
1267 character (C<!> unless otherwise defined). Yes, these do conflict, and
1268 neither works in the debugger at the moment.
1274 # Set up defaults for command recall and shell escape (note:
1275 # these currently don't work in linemode debugging).
1276 &recallCommand("!") unless defined $prc;
1277 &shellBang("!") unless defined $psh;
1281 We then set up the gigantic string containing the debugger help.
1282 We also set the limit on the number of arguments we'll display during a
1289 # If we didn't get a default for the length of eval/stack trace args,
1291 $maxtrace = 400 unless defined $maxtrace;
1293 =head2 SETTING UP THE DEBUGGER GREETING
1295 The debugger I<greeting> helps to inform the user how many debuggers are
1296 running, and whether the current debugger is the primary or a child.
1298 If we are the primary, we just hang onto our pid so we'll have it when
1299 or if we start a child debugger. If we are a child, we'll set things up
1300 so we'll have a unique greeting and so the parent will give us our own
1303 We save the current contents of the C<PERLDB_PIDS> environment variable
1304 because we mess around with it. We'll also need to hang onto it because
1305 we'll need it if we restart.
1307 Child debuggers make a label out of the current PID structure recorded in
1308 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1309 yet so the parent will give them one later via C<resetterm()>.
1313 # Save the current contents of the environment; we're about to
1314 # much with it. We'll need this if we have to restart.
1315 $ini_pids = $ENV{PERLDB_PIDS};
1317 if ( defined $ENV{PERLDB_PIDS} ) {
1319 # We're a child. Make us a label out of the current PID structure
1320 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1321 # a term yet so the parent will give us one later via resetterm().
1323 my $env_pids = $ENV{PERLDB_PIDS};
1324 $pids = "[$env_pids]";
1326 # Unless we are on OpenVMS, all programs under the DCL shell run under
1329 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1333 $ENV{PERLDB_PIDS} .= "->$$";
1337 } ## end if (defined $ENV{PERLDB_PIDS...
1340 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1341 # child debugger, and mark us as the parent, so we'll know to set up
1342 # more TTY's is we have to.
1343 $ENV{PERLDB_PIDS} = "$$";
1350 # Sets up $emacs as a synonym for $slave_editor.
1351 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1353 =head2 READING THE RC FILE
1355 The debugger will read a file of initialization options if supplied. If
1356 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1360 # As noted, this test really doesn't check accurately that the debugger
1361 # is running at a terminal or not.
1363 if ( -e "/dev/tty" ) { # this is the wrong metric!
1364 $rcfile = ".perldb";
1367 $rcfile = "perldb.ini";
1372 The debugger does a safety test of the file to be read. It must be owned
1373 either by the current user or root, and must only be writable by the owner.
1377 # This wraps a safety test around "do" to read and evaluate the init file.
1379 # This isn't really safe, because there's a race
1380 # between checking and opening. The solution is to
1381 # open and fstat the handle, but then you have to read and
1382 # eval the contents. But then the silly thing gets
1383 # your lexical scope, which is unfortunate at best.
1387 # Just exactly what part of the word "CORE::" don't you understand?
1388 local $SIG{__WARN__};
1389 local $SIG{__DIE__};
1391 unless ( is_safe_file($file) ) {
1392 CORE::warn <<EO_GRIPE;
1393 perldb: Must not source insecure rcfile $file.
1394 You or the superuser must be the owner, and it must not
1395 be writable by anyone but its owner.
1398 } ## end unless (is_safe_file($file...
1401 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1402 } ## end sub safe_do
1404 # This is the safety test itself.
1406 # Verifies that owner is either real user or superuser and that no
1407 # one but owner may write to it. This function is of limited use
1408 # when called on a path instead of upon a handle, because there are
1409 # no guarantees that filename (by dirent) whose file (by ino) is
1410 # eventually accessed is the same as the one tested.
1411 # Assumes that the file's existence is not in doubt.
1414 stat($path) || return; # mysteriously vaporized
1415 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1417 return 0 if $uid != 0 && $uid != $<;
1418 return 0 if $mode & 022;
1420 } ## end sub is_safe_file
1422 # If the rcfile (whichever one we decided was the right one to read)
1423 # exists, we safely do it.
1425 safe_do("./$rcfile");
1428 # If there isn't one here, try the user's home directory.
1429 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1430 safe_do("$ENV{HOME}/$rcfile");
1433 # Else try the login directory.
1434 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1435 safe_do("$ENV{LOGDIR}/$rcfile");
1438 # If the PERLDB_OPTS variable has options in it, parse those out next.
1439 if ( defined $ENV{PERLDB_OPTS} ) {
1440 parse_options( $ENV{PERLDB_OPTS} );
1445 The last thing we do during initialization is determine which subroutine is
1446 to be used to obtain a new terminal when a new debugger is started. Right now,
1447 the debugger only handles X Windows, OS/2, and Mac OS X (darwin).
1451 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1452 # Works if you're running an xterm or xterm-like window, or you're on
1453 # OS/2, or on Mac OS X. This may need some expansion.
1455 if (not defined &get_fork_TTY) # only if no routine exists
1457 if (defined $ENV{TERM} # If we know what kind
1458 # of terminal this is,
1459 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1460 and defined $ENV{DISPLAY} # and what display it's on,
1463 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1465 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1466 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1468 elsif ( $^O eq 'darwin' # If this is Mac OS X
1469 and defined $ENV{TERM_PROGRAM} # and we're running inside
1470 and $ENV{TERM_PROGRAM}
1471 eq 'Apple_Terminal' # Terminal.app
1474 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1476 } ## end if (not defined &get_fork_TTY...
1478 # untaint $^O, which may have been tainted by the last statement.
1479 # see bug [perl #24674]
1483 # Here begin the unreadable code. It needs fixing.
1485 =head2 RESTART PROCESSING
1487 This section handles the restart command. When the C<R> command is invoked, it
1488 tries to capture all of the state it can into environment variables, and
1489 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1490 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1491 the R command stuffed into the environment variables.
1493 PERLDB_RESTART - flag only, contains no restart data itself.
1494 PERLDB_HIST - command history, if it's available
1495 PERLDB_ON_LOAD - breakpoints set by the rc file
1496 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1497 PERLDB_VISITED - files that had breakpoints
1498 PERLDB_FILE_... - breakpoints for a file
1499 PERLDB_OPT - active options
1500 PERLDB_INC - the original @INC
1501 PERLDB_PRETYPE - preprompt debugger actions
1502 PERLDB_PRE - preprompt Perl code
1503 PERLDB_POST - post-prompt Perl code
1504 PERLDB_TYPEAHEAD - typeahead captured by readline()
1506 We chug through all these variables and plug the values saved in them
1507 back into the appropriate spots in the debugger.
1511 if ( exists $ENV{PERLDB_RESTART} ) {
1513 # We're restarting, so we don't need the flag that says to restart anymore.
1514 delete $ENV{PERLDB_RESTART};
1517 @hist = get_list('PERLDB_HIST');
1518 %break_on_load = get_list("PERLDB_ON_LOAD");
1519 %postponed = get_list("PERLDB_POSTPONE");
1523 share(%break_on_load);
1526 # restore breakpoints/actions
1527 my @had_breakpoints = get_list("PERLDB_VISITED");
1528 for ( 0 .. $#had_breakpoints ) {
1529 my %pf = get_list("PERLDB_FILE_$_");
1530 $postponed_file{ $had_breakpoints[$_] } = \%pf if %pf;
1534 my %opt = get_list("PERLDB_OPT");
1536 while ( ( $opt, $val ) = each %opt ) {
1537 $val =~ s/[\\\']/\\$1/g;
1538 parse_options("$opt'$val'");
1541 # restore original @INC
1542 @INC = get_list("PERLDB_INC");
1545 # return pre/postprompt actions and typeahead buffer
1546 $pretype = [ get_list("PERLDB_PRETYPE") ];
1547 $pre = [ get_list("PERLDB_PRE") ];
1548 $post = [ get_list("PERLDB_POST") ];
1549 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1550 } ## end if (exists $ENV{PERLDB_RESTART...
1552 =head2 SETTING UP THE TERMINAL
1554 Now, we'll decide how the debugger is going to interact with the user.
1555 If there's no TTY, we set the debugger to run non-stop; there's not going
1556 to be anyone there to enter commands.
1567 If there is a TTY, we have to determine who it belongs to before we can
1568 proceed. If this is a slave editor or graphical debugger (denoted by
1569 the first command-line switch being '-emacs'), we shift this off and
1570 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1576 # Is Perl being run from a slave editor or graphical debugger?
1577 # If so, don't use readline, and set $slave_editor = 1.
1579 ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) );
1580 $rl = 0, shift(@main::ARGV) if $slave_editor;
1582 #require Term::ReadLine;
1586 We then determine what the console should be on various systems:
1590 =item * Cygwin - We use C<stdin> instead of a separate device.
1594 if ( $^O eq 'cygwin' ) {
1596 # /dev/tty is binary. use stdin for textmode
1600 =item * Unix - use C</dev/tty>.
1604 elsif ( -e "/dev/tty" ) {
1605 $console = "/dev/tty";
1608 =item * Windows or MSDOS - use C<con>.
1612 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1616 =item * MacOS - use C<Dev:Console:Perl Debug> if this is the MPW version; C<Dev:
1619 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.
1623 elsif ( $^O eq 'MacOS' ) {
1624 if ( $MacPerl::Version !~ /MPW/ ) {
1626 "Dev:Console:Perl Debug"; # Separate window for application
1629 $console = "Dev:Console";
1631 } ## end elsif ($^O eq 'MacOS')
1633 =item * VMS - use C<sys$command>.
1639 # everything else is ...
1640 $console = "sys\$command";
1647 Several other systems don't use a specific console. We C<undef $console>
1648 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1649 with a slave editor, Epoc).
1653 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1655 # /dev/tty is binary. use stdin for textmode
1659 if ( $^O eq 'NetWare' ) {
1661 # /dev/tty is binary. use stdin for textmode
1665 # In OS/2, we need to use STDIN to get textmode too, even though
1666 # it pretty much looks like Unix otherwise.
1667 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1672 # EPOC also falls into the 'got to use STDIN' camp.
1673 if ( $^O eq 'epoc' ) {
1679 If there is a TTY hanging around from a parent, we use that as the console.
1683 $console = $tty if defined $tty;
1685 =head2 SOCKET HANDLING
1687 The debugger is capable of opening a socket and carrying out a debugging
1688 session over the socket.
1690 If C<RemotePort> was defined in the options, the debugger assumes that it
1691 should try to start a debugging session on that port. It builds the socket
1692 and then tries to connect the input and output filehandles to it.
1696 # Handle socket stuff.
1698 if ( defined $remoteport ) {
1700 # If RemotePort was defined in the options, connect input and output
1703 $OUT = new IO::Socket::INET(
1705 PeerAddr => $remoteport,
1708 if ( !$OUT ) { die "Unable to connect to remote host: $remoteport\n"; }
1710 } ## end if (defined $remoteport)
1714 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1715 this is probably a situation where multiple debuggers are running (for example,
1716 a backticked command that starts up another debugger). We create a new IN and
1717 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1725 # Two debuggers running (probably a system or a backtick that invokes
1726 # the debugger itself under the running one). create a new IN and OUT
1727 # filehandle, and do the necessary mojo to create a new tty if we
1728 # know how, and we can.
1729 create_IN_OUT(4) if $CreateTTY & 4;
1732 # If we have a console, check to see if there are separate ins and
1733 # outs to open. (They are assumed identical if not.)
1735 my ( $i, $o ) = split /,/, $console;
1736 $o = $i unless defined $o;
1738 # read/write on in, or just read, or read on STDIN.
1740 || open( IN, "<$i" )
1741 || open( IN, "<&STDIN" );
1743 # read/write/create/clobber out, or write/create/clobber out,
1744 # or merge with STDERR, or merge with STDOUT.
1746 || open( OUT, ">$o" )
1747 || open( OUT, ">&STDERR" )
1748 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1750 } ## end if ($console)
1751 elsif ( not defined $console ) {
1753 # No console. Open STDIN.
1754 open( IN, "<&STDIN" );
1756 # merge with STDERR, or with STDOUT.
1757 open( OUT, ">&STDERR" )
1758 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1759 $console = 'STDIN/OUT';
1760 } ## end elsif (not defined $console)
1762 # Keep copies of the filehandles so that when the pager runs, it
1763 # can close standard input without clobbering ours.
1764 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1765 } ## end elsif (from if(defined $remoteport))
1767 # Unbuffer DB::OUT. We need to see responses right away.
1768 my $previous = select($OUT);
1769 $| = 1; # for DB::OUT
1772 # Line info goes to debugger output unless pointed elsewhere.
1773 # Pointing elsewhere makes it possible for slave editors to
1774 # keep track of file and position. We have both a filehandle
1775 # and a I/O description to keep track of.
1776 $LINEINFO = $OUT unless defined $LINEINFO;
1777 $lineinfo = $console unless defined $lineinfo;
1778 # share($LINEINFO); # <- unable to share globs
1783 To finish initialization, we show the debugger greeting,
1784 and then call the C<afterinit()> subroutine if there is one.
1788 # Show the debugger greeting.
1789 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1790 unless ($runnonstop) {
1793 if ( $term_pid eq '-1' ) {
1794 print $OUT "\nDaughter DB session started...\n";
1797 print $OUT "\nLoading DB routines from $header\n";
1800 $slave_editor ? "enabled" : "available", ".\n"
1803 "\nEnter h or `h h' for help, or `$doccmd perldebug' for more help.\n\n";
1804 } ## end else [ if ($term_pid eq '-1')
1805 } ## end unless ($runnonstop)
1806 } ## end else [ if ($notty)
1808 # XXX This looks like a bug to me.
1809 # Why copy to @ARGS and then futz with @args?
1812 # Make sure backslashes before single quotes are stripped out, and
1813 # keep args unless they are numeric (XXX why?)
1814 # s/\'/\\\'/g; # removed while not justified understandably
1815 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1818 # If there was an afterinit() sub defined, call it. It will get
1819 # executed in our scope, so it can fiddle with debugger globals.
1820 if ( defined &afterinit ) { # May be defined in $rcfile
1824 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1827 ############################################################ Subroutines
1833 This gigantic subroutine is the heart of the debugger. Called before every
1834 statement, its job is to determine if a breakpoint has been reached, and
1835 stop if so; read commands from the user, parse them, and execute
1836 them, and hen send execution off to the next statement.
1838 Note that the order in which the commands are processed is very important;
1839 some commands earlier in the loop will actually alter the C<$cmd> variable
1840 to create other commands to be executed later. This is all highly I<optimized>
1841 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1842 see what's happening in any given command.
1848 # lock the debugger and get the thread id for the prompt
1851 if ($ENV{PERL5DB_THREADED}) {
1852 $tid = eval { "[".threads->self->tid."]" };
1855 # Check for whether we should be running continuously or not.
1856 # _After_ the perl program is compiled, $single is set to 1:
1857 if ( $single and not $second_time++ ) {
1859 # Options say run non-stop. Run until we get an interrupt.
1860 if ($runnonstop) { # Disable until signal
1861 # If there's any call stack in place, turn off single
1862 # stepping into subs throughout the stack.
1863 for ( $i = 0 ; $i <= $stack_depth ; ) {
1864 $stack[ $i++ ] &= ~1;
1867 # And we are now no longer in single-step mode.
1870 # If we simply returned at this point, we wouldn't get
1871 # the trace info. Fall on through.
1873 } ## end if ($runnonstop)
1875 elsif ($ImmediateStop) {
1877 # We are supposed to stop here; XXX probably a break.
1878 $ImmediateStop = 0; # We've processed it; turn it off
1879 $signal = 1; # Simulate an interrupt to force
1880 # us into the command loop
1882 } ## end if ($single and not $second_time...
1884 # If we're in single-step mode, or an interrupt (real or fake)
1885 # has occurred, turn off non-stop mode.
1886 $runnonstop = 0 if $single or $signal;
1888 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1889 # The code being debugged may have altered them.
1892 # Since DB::DB gets called after every line, we can use caller() to
1893 # figure out where we last were executing. Sneaky, eh? This works because
1894 # caller is returning all the extra information when called from the
1896 local ( $package, $filename, $line ) = caller;
1897 local $filename_ini = $filename;
1899 # set up the context for DB::eval, so it can properly execute
1900 # code on behalf of the user. We add the package in so that the
1901 # code is eval'ed in the proper package (not in the debugger!).
1902 local $usercontext =
1903 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' . "package $package;";
1905 # Create an alias to the active file magical array to simplify
1907 local (*dbline) = $main::{ '_<' . $filename };
1909 # we need to check for pseudofiles on Mac OS (these are files
1910 # not attached to a filename, but instead stored in Dev:Pseudo)
1911 if ( $^O eq 'MacOS' && $#dbline < 0 ) {
1912 $filename_ini = $filename = 'Dev:Pseudo';
1913 *dbline = $main::{ '_<' . $filename };
1916 # Last line in the program.
1917 local $max = $#dbline;
1919 # if we have something here, see if we should break.
1921 && ( ( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1924 # Stop if the stop criterion says to just stop.
1925 if ( $stop eq '1' ) {
1929 # It's a conditional stop; eval it in the user's context and
1930 # see if we should stop. If so, remove the one-time sigil.
1932 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1934 $dbline{$line} =~ s/;9($|\0)/$1/;
1936 } ## end if ($dbline{$line} && ...
1938 # Preserve the current stop-or-not, and see if any of the W
1939 # (watch expressions) has changed.
1940 my $was_signal = $signal;
1942 # If we have any watch expressions ...
1944 for ( my $n = 0 ; $n <= $#to_watch ; $n++ ) {
1945 $evalarg = $to_watch[$n];
1946 local $onetimeDump; # Tell DB::eval() to not output results
1948 # Fix context DB::eval() wants to return an array, but
1949 # we need a scalar here.
1950 my ($val) = join( "', '", &eval );
1951 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
1954 if ( $val ne $old_watch[$n] ) {
1956 # Yep! Show the difference, and fake an interrupt.
1959 Watchpoint $n:\t$to_watch[$n] changed:
1960 old value:\t$old_watch[$n]
1963 $old_watch[$n] = $val;
1964 } ## end if ($val ne $old_watch...
1965 } ## end for (my $n = 0 ; $n <= ...
1966 } ## end if ($trace & 2)
1968 =head2 C<watchfunction()>
1970 C<watchfunction()> is a function that can be defined by the user; it is a
1971 function which will be run on each entry to C<DB::DB>; it gets the
1972 current package, filename, and line as its parameters.
1974 The watchfunction can do anything it likes; it is executing in the
1975 debugger's context, so it has access to all of the debugger's internal
1976 data structures and functions.
1978 C<watchfunction()> can control the debugger's actions. Any of the following
1979 will cause the debugger to return control to the user's program after
1980 C<watchfunction()> executes:
1986 Returning a false value from the C<watchfunction()> itself.
1990 Altering C<$single> to a false value.
1994 Altering C<$signal> to a false value.
1998 Turning off the C<4> bit in C<$trace> (this also disables the
1999 check for C<watchfunction()>. This can be done with
2007 # If there's a user-defined DB::watchfunction, call it with the
2008 # current package, filename, and line. The function executes in
2010 if ( $trace & 4 ) { # User-installed watch
2012 if watchfunction( $package, $filename, $line )
2015 and not( $trace & ~4 );
2016 } ## end if ($trace & 4)
2018 # Pick up any alteration to $signal in the watchfunction, and
2019 # turn off the signal now.
2020 $was_signal = $signal;
2023 =head2 GETTING READY TO EXECUTE COMMANDS
2025 The debugger decides to take control if single-step mode is on, the
2026 C<t> command was entered, or the user generated a signal. If the program
2027 has fallen off the end, we set things up so that entering further commands
2028 won't cause trouble, and we say that the program is over.
2032 # Check to see if we should grab control ($single true,
2033 # trace set appropriately, or we got a signal).
2034 if ( $single || ( $trace & 1 ) || $was_signal ) {
2036 # Yes, grab control.
2037 if ($slave_editor) {
2039 # Tell the editor to update its position.
2040 $position = "\032\032$filename:$line:0\n";
2041 print_lineinfo($position);
2046 Special check: if we're in package C<DB::fake>, we've gone through the
2047 C<END> block at least once. We set up everything so that we can continue
2048 to enter commands and have a valid context to be in.
2052 elsif ( $package eq 'DB::fake' ) {
2054 # Fallen off the end already.
2057 Debugged program terminated. Use B<q> to quit or B<R> to restart,
2058 use B<o> I<inhibit_exit> to avoid stopping after program termination,
2059 B<h q>, B<h R> or B<h o> to get additional info.
2062 # Set the DB::eval context appropriately.
2065 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;'
2066 . "package $package;"; # this won't let them modify, alas
2067 } ## end elsif ($package eq 'DB::fake')
2071 If the program hasn't finished executing, we scan forward to the
2072 next executable line, print that out, build the prompt from the file and line
2073 number information, and print that.
2079 # Still somewhere in the midst of execution. Set up the
2081 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
2082 # Perl 5 ones (sorry, we don't print Klingon
2085 $prefix = $sub =~ /::/ ? "" : "${'package'}::";
2086 $prefix .= "$sub($filename:";
2087 $after = ( $dbline[$line] =~ /\n$/ ? '' : "\n" );
2089 # Break up the prompt if it's really long.
2090 if ( length($prefix) > 30 ) {
2091 $position = "$prefix$line):\n$line:\t$dbline[$line]$after";
2097 $position = "$prefix$line$infix$dbline[$line]$after";
2100 # Print current line info, indenting if necessary.
2102 print_lineinfo( ' ' x $stack_depth,
2103 "$line:\t$dbline[$line]$after" );
2106 print_lineinfo($position);
2109 # Scan forward, stopping at either the end or the next
2111 for ( $i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i )
2114 # Drop out on null statements, block closers, and comments.
2115 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/;
2117 # Drop out if the user interrupted us.
2120 # Append a newline if the line doesn't have one. Can happen
2121 # in eval'ed text, for instance.
2122 $after = ( $dbline[$i] =~ /\n$/ ? '' : "\n" );
2124 # Next executable line.
2125 $incr_pos = "$prefix$i$infix$dbline[$i]$after";
2126 $position .= $incr_pos;
2129 # Print it indented if tracing is on.
2130 print_lineinfo( ' ' x $stack_depth,
2131 "$i:\t$dbline[$i]$after" );
2134 print_lineinfo($incr_pos);
2136 } ## end for ($i = $line + 1 ; $i...
2137 } ## end else [ if ($slave_editor)
2138 } ## end if ($single || ($trace...
2142 If there's an action to be executed for the line we stopped at, execute it.
2143 If there are any preprompt actions, execute those as well.
2147 # If there's an action, do it now.
2148 $evalarg = $action, &eval if $action;
2150 # Are we nested another level (e.g., did we evaluate a function
2151 # that had a breakpoint in it at the debugger prompt)?
2152 if ( $single || $was_signal ) {
2154 # Yes, go down a level.
2155 local $level = $level + 1;
2157 # Do any pre-prompt actions.
2158 foreach $evalarg (@$pre) {
2162 # Complain about too much recursion if we passed the limit.
2163 print $OUT $stack_depth . " levels deep in subroutine calls!\n"
2166 # The line we're currently on. Set $incr to -1 to stay here
2167 # until we get a command that tells us to advance.
2169 $incr = -1; # for backward motion.
2171 # Tack preprompt debugger actions ahead of any actual input.
2172 @typeahead = ( @$pretype, @typeahead );
2174 =head2 WHERE ARE WE?
2176 XXX Relocate this section?
2178 The debugger normally shows the line corresponding to the current line of
2179 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2180 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2182 C<$incr> controls by how many lines the I<current> line should move forward
2183 after a command is executed. If set to -1, this indicates that the I<current>
2184 line shouldn't change.
2186 C<$start> is the I<current> line. It is used for things like knowing where to
2187 move forwards or backwards from when doing an C<L> or C<-> command.
2189 C<$max> tells the debugger where the last line of the current file is. It's
2190 used to terminate loops most often.
2192 =head2 THE COMMAND LOOP
2194 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2201 The outer part of the loop, starting at the C<CMD> label. This loop
2202 reads a command and then executes it.
2206 The inner part of the loop, starting at the C<PIPE> label. This part
2207 is wholly contained inside the C<CMD> block and only executes a command.
2208 Used to handle commands running inside a pager.
2212 So why have two labels to restart the loop? Because sometimes, it's easier to
2213 have a command I<generate> another command and then re-execute the loop to do
2214 the new command. This is faster, but perhaps a bit more convoluted.
2218 # The big command dispatch loop. It keeps running until the
2219 # user yields up control again.
2221 # If we have a terminal for input, and we get something back
2222 # from readline(), keep on processing.
2226 # We have a terminal, or can get one ...
2227 ( $term || &setterm ),
2229 # ... and it belogs to this PID or we get one for this PID ...
2230 ( $term_pid == $$ or resetterm(1) ),
2232 # ... and we got a line of command input ...
2235 "$pidprompt $tid DB"
2238 . ( '>' x $level ) . " "
2245 # ... try to execute the input as debugger commands.
2247 # Don't stop running.
2250 # No signal is active.
2253 # Handle continued commands (ending with \):
2254 $cmd =~ s/\\$/\n/ && do {
2255 $cmd .= &readline(" cont: ");
2259 =head4 The null command
2261 A newline entered by itself means I<re-execute the last command>. We grab the
2262 command out of C<$laststep> (where it was recorded previously), and copy it
2263 back into C<$cmd> to be executed below. If there wasn't any previous command,
2264 we'll do nothing below (no command will match). If there was, we also save it
2265 in the command history and fall through to allow the command parsing to pick
2270 # Empty input means repeat the last command.
2271 $cmd =~ /^$/ && ( $cmd = $laststep );
2272 chomp($cmd); # get rid of the annoying extra newline
2273 push( @hist, $cmd ) if length($cmd) > 1;
2274 push( @truehist, $cmd );
2278 # This is a restart point for commands that didn't arrive
2279 # via direct user input. It allows us to 'redo PIPE' to
2280 # re-execute command processing without reading a new command.
2282 $cmd =~ s/^\s+//s; # trim annoying leading whitespace
2283 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace
2284 ($i) = split( /\s+/, $cmd );
2286 =head3 COMMAND ALIASES
2288 The debugger can create aliases for commands (these are stored in the
2289 C<%alias> hash). Before a command is executed, the command loop looks it up
2290 in the alias hash and substitutes the contents of the alias for the command,
2291 completely replacing it.
2295 # See if there's an alias for the command, and set it up if so.
2298 # Squelch signal handling; we want to keep control here
2299 # if something goes loco during the alias eval.
2300 local $SIG{__DIE__};
2301 local $SIG{__WARN__};
2303 # This is a command, so we eval it in the DEBUGGER's
2304 # scope! Otherwise, we can't see the special debugger
2305 # variables, or get to the debugger's subs. (Well, we
2306 # _could_, but why make it even more complicated?)
2307 eval "\$cmd =~ $alias{$i}";
2310 print $OUT "Couldn't evaluate `$i' alias: $@";
2313 } ## end if ($alias{$i})
2315 =head3 MAIN-LINE COMMANDS
2317 All of these commands work up to and after the program being debugged has
2322 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2323 try to execute further, cleaning any restart-related stuff out of the
2324 environment, and executing with the last value of C<$?>.
2328 $cmd =~ /^q$/ && do {
2336 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2340 $cmd =~ /^t$/ && do {
2343 print $OUT "Trace = "
2344 . ( ( $trace & 1 ) ? "on" : "off" ) . "\n";
2348 =head4 C<S> - list subroutines matching/not matching a pattern
2350 Walks through C<%sub>, checking to see whether or not to print the name.
2354 $cmd =~ /^S(\s+(!)?(.+))?$/ && do {
2356 $Srev = defined $2; # Reverse scan?
2357 $Spatt = $3; # The pattern (if any) to use.
2358 $Snocheck = !defined $1; # No args - print all subs.
2360 # Need to make these sane here.
2364 # Search through the debugger's magical hash of subs.
2365 # If $nocheck is true, just print the sub name.
2366 # Otherwise, check it against the pattern. We then use
2367 # the XOR trick to reverse the condition as required.
2368 foreach $subname ( sort( keys %sub ) ) {
2369 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2370 print $OUT $subname, "\n";
2376 =head4 C<X> - list variables in current package
2378 Since the C<V> command actually processes this, just change this to the
2379 appropriate C<V> command and fall through.
2383 $cmd =~ s/^X\b/V $package/;
2385 =head4 C<V> - list variables
2387 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2391 # Bare V commands get the currently-being-debugged package
2393 $cmd =~ /^V$/ && do {
2394 $cmd = "V $package";
2397 # V - show variables in package.
2398 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
2400 # Save the currently selected filehandle and
2401 # force output to debugger's filehandle (dumpvar
2402 # just does "print" for output).
2403 local ($savout) = select($OUT);
2405 # Grab package name and variables to dump.
2407 @vars = split( ' ', $2 );
2409 # If main::dumpvar isn't here, get it.
2410 do 'dumpvar.pl' unless defined &main::dumpvar;
2411 if ( defined &main::dumpvar ) {
2413 # We got it. Turn off subroutine entry/exit messages
2414 # for the moment, along with return values.
2418 # must detect sigpipe failures - not catching
2419 # then will cause the debugger to die.
2423 defined $option{dumpDepth}
2424 ? $option{dumpDepth}
2425 : -1, # assume -1 unless specified
2430 # The die doesn't need to include the $@, because
2431 # it will automatically get propagated for us.
2433 die unless $@ =~ /dumpvar print failed/;
2435 } ## end if (defined &main::dumpvar)
2438 # Couldn't load dumpvar.
2439 print $OUT "dumpvar.pl not available.\n";
2442 # Restore the output filehandle, and go round again.
2447 =head4 C<x> - evaluate and print an expression
2449 Hands the expression off to C<DB::eval>, setting it up to print the value
2450 via C<dumpvar.pl> instead of just printing it directly.
2454 $cmd =~ s/^x\b/ / && do { # Remainder gets done by DB::eval()
2455 $onetimeDump = 'dump'; # main::dumpvar shows the output
2457 # handle special "x 3 blah" syntax XXX propagate
2458 # doc back to special variables.
2459 if ( $cmd =~ s/^\s*(\d+)(?=\s)/ / ) {
2460 $onetimedumpDepth = $1;
2464 =head4 C<m> - print methods
2466 Just uses C<DB::methods> to determine what methods are available.
2470 $cmd =~ s/^m\s+([\w:]+)\s*$/ / && do {
2475 # m expr - set up DB::eval to do the work
2476 $cmd =~ s/^m\b/ / && do { # Rest gets done by DB::eval()
2477 $onetimeDump = 'methods'; # method output gets used there
2480 =head4 C<f> - switch files
2484 $cmd =~ /^f\b\s*(.*)/ && do {
2488 # help for no arguments (old-style was return from sub).
2491 "The old f command is now the r command.\n"; # hint
2492 print $OUT "The new f command switches filenames.\n";
2494 } ## end if (!$file)
2496 # if not in magic file list, try a close match.
2497 if ( !defined $main::{ '_<' . $file } ) {
2498 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2500 $try = substr( $try, 2 );
2501 print $OUT "Choosing $try matching `$file':\n";
2504 } ## end if (($try) = grep(m#^_<.*$file#...
2505 } ## end if (!defined $main::{ ...
2507 # If not successfully switched now, we failed.
2508 if ( !defined $main::{ '_<' . $file } ) {
2509 print $OUT "No file matching `$file' is loaded.\n";
2513 # We switched, so switch the debugger internals around.
2514 elsif ( $file ne $filename ) {
2515 *dbline = $main::{ '_<' . $file };
2520 } ## end elsif ($file ne $filename)
2522 # We didn't switch; say we didn't.
2524 print $OUT "Already in $file.\n";
2529 =head4 C<.> - return to last-executed line.
2531 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2532 and then we look up the line in the magical C<%dbline> hash.
2537 $cmd =~ /^\.$/ && do {
2538 $incr = -1; # stay at current line
2540 # Reset everything to the old location.
2542 $filename = $filename_ini;
2543 *dbline = $main::{ '_<' . $filename };
2547 print_lineinfo($position);
2551 =head4 C<-> - back one window
2553 We change C<$start> to be one window back; if we go back past the first line,
2554 we set it to be the first line. We ser C<$incr> to put us back at the
2555 currently-executing line, and then put a C<l $start +> (list one window from
2556 C<$start>) in C<$cmd> to be executed later.
2560 # - - back a window.
2561 $cmd =~ /^-$/ && do {
2563 # back up by a window; go to 1 if back too far.
2564 $start -= $incr + $window + 1;
2565 $start = 1 if $start <= 0;
2566 $incr = $window - 1;
2568 # Generate and execute a "l +" command (handled below).
2569 $cmd = 'l ' . ($start) . '+';
2572 =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>, {, {{>
2574 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2575 problems, most notably that the default case of several commands destroying
2576 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2577 retain the old commands for those who were used to using them or who preferred
2578 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2579 deal with them instead of processing them in-line.
2583 # All of these commands were remapped in perl 5.8.0;
2584 # we send them off to the secondary dispatcher (see below).
2585 $cmd =~ /^([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so && do {
2586 &cmd_wrapper( $1, $2, $line );
2590 =head4 C<y> - List lexicals in higher scope
2592 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2593 above the current one and then displays then using C<dumpvar.pl>.
2597 $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/ && do {
2599 # See if we've got the necessary support.
2600 eval { require PadWalker; PadWalker->VERSION(0.08) }
2603 ? "PadWalker module not found - please install\n"
2608 # Load up dumpvar if we don't have it. If we can, that is.
2609 do 'dumpvar.pl' unless defined &main::dumpvar;
2610 defined &main::dumpvar
2611 or print $OUT "dumpvar.pl not available.\n"
2614 # Got all the modules we need. Find them and print them.
2615 my @vars = split( ' ', $2 || '' );
2618 my $h = eval { PadWalker::peek_my( ( $1 || 0 ) + 1 ) };
2620 # Oops. Can't find it.
2621 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2623 # Show the desired vars with dumplex().
2624 my $savout = select($OUT);
2626 # Have dumplex dump the lexicals.
2627 dumpvar::dumplex( $_, $h->{$_},
2628 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
2635 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2637 All of the commands below this point don't work after the program being
2638 debugged has ended. All of them check to see if the program has ended; this
2639 allows the commands to be relocated without worrying about a 'line of
2640 demarcation' above which commands can be entered anytime, and below which
2643 =head4 C<n> - single step, but don't trace down into subs
2645 Done by setting C<$single> to 2, which forces subs to execute straight through
2646 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2647 so a null command knows what to re-execute.
2652 $cmd =~ /^n$/ && do {
2653 end_report(), next CMD if $finished and $level <= 1;
2655 # Single step, but don't enter subs.
2658 # Save for empty command (repeat last).
2663 =head4 C<s> - single-step, entering subs
2665 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2666 subs. Also saves C<s> as C<$lastcmd>.
2671 $cmd =~ /^s$/ && do {
2673 # Get out and restart the command loop if program
2675 end_report(), next CMD if $finished and $level <= 1;
2677 # Single step should enter subs.
2680 # Save for empty command (repeat last).
2685 =head4 C<c> - run continuously, setting an optional breakpoint
2687 Most of the code for this command is taken up with locating the optional
2688 breakpoint, which is either a subroutine name or a line number. We set
2689 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2690 in this and all call levels above this one.
2694 # c - start continuous execution.
2695 $cmd =~ /^c\b\s*([\w:]*)\s*$/ && do {
2697 # Hey, show's over. The debugged program finished
2698 # executing already.
2699 end_report(), next CMD if $finished and $level <= 1;
2701 # Capture the place to put a one-time break.
2704 # Probably not needed, since we finish an interactive
2705 # sub-session anyway...
2706 # local $filename = $filename;
2707 # local *dbline = *dbline; # XXX Would this work?!
2709 # The above question wonders if localizing the alias
2710 # to the magic array works or not. Since it's commented
2711 # out, we'll just leave that to speculation for now.
2713 # If the "subname" isn't all digits, we'll assume it
2714 # is a subroutine name, and try to find it.
2715 if ( $subname =~ /\D/ ) { # subroutine name
2716 # Qualify it to the current package unless it's
2717 # already qualified.
2718 $subname = $package . "::" . $subname
2719 unless $subname =~ /::/;
2721 # find_sub will return "file:line_number" corresponding
2722 # to where the subroutine is defined; we call find_sub,
2723 # break up the return value, and assign it in one
2725 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2727 # Force the line number to be numeric.
2730 # If we got a line number, we found the sub.
2733 # Switch all the debugger's internals around so
2734 # we're actually working with that file.
2736 *dbline = $main::{ '_<' . $filename };
2738 # Mark that there's a breakpoint in this file.
2739 $had_breakpoints{$filename} |= 1;
2741 # Scan forward to the first executable line
2742 # after the 'sub whatever' line.
2744 ++$i while $dbline[$i] == 0 && $i < $max;
2747 # We didn't find a sub by that name.
2749 print $OUT "Subroutine $subname not found.\n";
2752 } ## end if ($subname =~ /\D/)
2754 # At this point, either the subname was all digits (an
2755 # absolute line-break request) or we've scanned through
2756 # the code following the definition of the sub, looking
2757 # for an executable, which we may or may not have found.
2759 # If $i (which we set $subname from) is non-zero, we
2760 # got a request to break at some line somewhere. On
2761 # one hand, if there wasn't any real subroutine name
2762 # involved, this will be a request to break in the current
2763 # file at the specified line, so we have to check to make
2764 # sure that the line specified really is breakable.
2766 # On the other hand, if there was a subname supplied, the
2767 # preceding block has moved us to the proper file and
2768 # location within that file, and then scanned forward
2769 # looking for the next executable line. We have to make
2770 # sure that one was found.
2772 # On the gripping hand, we can't do anything unless the
2773 # current value of $i points to a valid breakable line.
2778 if ( $dbline[$i] == 0 ) {
2779 print $OUT "Line $i not breakable.\n";
2783 # Yes. Set up the one-time-break sigil.
2784 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2787 # Turn off stack tracing from here up.
2788 for ( $i = 0 ; $i <= $stack_depth ; ) {
2789 $stack[ $i++ ] &= ~1;
2794 =head4 C<r> - return from a subroutine
2796 For C<r> to work properly, the debugger has to stop execution again
2797 immediately after the return is executed. This is done by forcing
2798 single-stepping to be on in the call level above the current one. If
2799 we are printing return values when a C<r> is executed, set C<$doret>
2800 appropriately, and force us out of the command loop.
2804 # r - return from the current subroutine.
2805 $cmd =~ /^r$/ && do {
2807 # Can't do anythign if the program's over.
2808 end_report(), next CMD if $finished and $level <= 1;
2810 # Turn on stack trace.
2811 $stack[$stack_depth] |= 1;
2813 # Print return value unless the stack is empty.
2814 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2818 =head4 C<T> - stack trace
2820 Just calls C<DB::print_trace>.
2824 $cmd =~ /^T$/ && do {
2825 print_trace( $OUT, 1 ); # skip DB
2829 =head4 C<w> - List window around current line.
2831 Just calls C<DB::cmd_w>.
2835 $cmd =~ /^w\b\s*(.*)/s && do { &cmd_w( 'w', $1 ); next CMD; };
2837 =head4 C<W> - watch-expression processing.
2839 Just calls C<DB::cmd_W>.
2843 $cmd =~ /^W\b\s*(.*)/s && do { &cmd_W( 'W', $1 ); next CMD; };
2845 =head4 C</> - search forward for a string in the source
2847 We take the argument and treat it as a pattern. If it turns out to be a
2848 bad one, we return the error we got from trying to C<eval> it and exit.
2849 If not, we create some code to do the search and C<eval> it so it can't
2854 $cmd =~ /^\/(.*)$/ && do {
2856 # The pattern as a string.
2859 # Remove the final slash.
2860 $inpat =~ s:([^\\])/$:$1:;
2862 # If the pattern isn't null ...
2863 if ( $inpat ne "" ) {
2865 # Turn of warn and die procesing for a bit.
2866 local $SIG{__DIE__};
2867 local $SIG{__WARN__};
2869 # Create the pattern.
2870 eval '$inpat =~ m' . "\a$inpat\a";
2873 # Oops. Bad pattern. No biscuit.
2874 # Print the eval error and go back for more
2880 } ## end if ($inpat ne "")
2882 # Set up to stop on wrap-around.
2885 # Don't move off the current line.
2888 # Done in eval so nothing breaks if the pattern
2889 # does something weird.
2892 # Move ahead one line.
2895 # Wrap if we pass the last line.
2896 $start = 1 if ($start > $max);
2898 # Stop if we have gotten back to this line again,
2899 last if ($start == $end);
2901 # A hit! (Note, though, that we are doing
2902 # case-insensitive matching. Maybe a qr//
2903 # expression would be better, so the user could
2904 # do case-sensitive matching if desired.
2905 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2906 if ($slave_editor) {
2907 # Handle proper escaping in the slave.
2908 print $OUT "\032\032$filename:$start:0\n";
2911 # Just print the line normally.
2912 print $OUT "$start:\t",$dbline[$start],"\n";
2914 # And quit since we found something.
2919 # If we wrapped, there never was a match.
2920 print $OUT "/$pat/: not found\n" if ( $start == $end );
2924 =head4 C<?> - search backward for a string in the source
2926 Same as for C</>, except the loop runs backwards.
2930 # ? - backward pattern search.
2931 $cmd =~ /^\?(.*)$/ && do {
2933 # Get the pattern, remove trailing question mark.
2935 $inpat =~ s:([^\\])\?$:$1:;
2937 # If we've got one ...
2938 if ( $inpat ne "" ) {
2940 # Turn off die & warn handlers.
2941 local $SIG{__DIE__};
2942 local $SIG{__WARN__};
2943 eval '$inpat =~ m' . "\a$inpat\a";
2947 # Ouch. Not good. Print the error.
2952 } ## end if ($inpat ne "")
2954 # Where we are now is where to stop after wraparound.
2957 # Don't move away from this line.
2960 # Search inside the eval to prevent pattern badness
2967 # Wrap if we pass the first line.
2969 $start = $max if ($start <= 0);
2971 # Quit if we get back where we started,
2972 last if ($start == $end);
2975 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2976 if ($slave_editor) {
2977 # Yep, follow slave editor requirements.
2978 print $OUT "\032\032$filename:$start:0\n";
2981 # Yep, just print normally.
2982 print $OUT "$start:\t",$dbline[$start],"\n";
2990 # Say we failed if the loop never found anything,
2991 print $OUT "?$pat?: not found\n" if ( $start == $end );
2995 =head4 C<$rc> - Recall command
2997 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2998 that the terminal supports history). It find the the command required, puts it
2999 into C<$cmd>, and redoes the loop to execute it.
3003 # $rc - recall command.
3004 $cmd =~ /^$rc+\s*(-)?(\d+)?$/ && do {
3006 # No arguments, take one thing off history.
3007 pop(@hist) if length($cmd) > 1;
3009 # Relative (- found)?
3010 # Y - index back from most recent (by 1 if bare minus)
3011 # N - go to that particular command slot or the last
3012 # thing if nothing following.
3013 $i = $1 ? ( $#hist - ( $2 || 1 ) ) : ( $2 || $#hist );
3015 # Pick out the command desired.
3018 # Print the command to be executed and restart the loop
3019 # with that command in the buffer.
3020 print $OUT $cmd, "\n";
3024 =head4 C<$sh$sh> - C<system()> command
3026 Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
3027 C<STDOUT> from getting messed up.
3031 # $sh$sh - run a shell command (if it's all ASCII).
3032 # Can't run shell commands with Unicode in the debugger, hmm.
3033 $cmd =~ /^$sh$sh\s*([\x00-\xff]*)/ && do {
3040 =head4 C<$rc I<pattern> $rc> - Search command history
3042 Another command to manipulate C<@hist>: this one searches it with a pattern.
3043 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
3047 # $rc pattern $rc - find a command in the history.
3048 $cmd =~ /^$rc([^$rc].*)$/ && do {
3050 # Create the pattern to use.
3053 # Toss off last entry if length is >1 (and it always is).
3054 pop(@hist) if length($cmd) > 1;
3056 # Look backward through the history.
3057 for ( $i = $#hist ; $i ; --$i ) {
3059 # Stop if we find it.
3060 last if $hist[$i] =~ /$pat/;
3066 print $OUT "No such command!\n\n";
3070 # Found it. Put it in the buffer, print it, and process it.
3072 print $OUT $cmd, "\n";
3076 =head4 C<$sh> - Invoke a shell
3078 Uses C<DB::system> to invoke a shell.
3082 # $sh - start a shell.
3083 $cmd =~ /^$sh$/ && do {
3085 # Run the user's shell. If none defined, run Bourne.
3086 # We resume execution when the shell terminates.
3087 &system( $ENV{SHELL} || "/bin/sh" );
3091 =head4 C<$sh I<command>> - Force execution of a command in a shell
3093 Like the above, but the command is passed to the shell. Again, we use
3094 C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
3098 # $sh command - start a shell and run a command in it.
3099 $cmd =~ /^$sh\s*([\x00-\xff]*)/ && do {
3101 # XXX: using csh or tcsh destroys sigint retvals!
3102 #&system($1); # use this instead
3104 # use the user's shell, or Bourne if none defined.
3105 &system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3109 =head4 C<H> - display commands in history
3111 Prints the contents of C<@hist> (if any).
3115 $cmd =~ /^H\b\s*\*/ && do {
3116 @hist = @truehist = ();
3117 print $OUT "History cleansed\n";
3121 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
3123 # Anything other than negative numbers is ignored by
3124 # the (incorrect) pattern, so this test does nothing.
3125 $end = $2 ? ( $#hist - $2 ) : 0;
3127 # Set to the minimum if less than zero.
3128 $hist = 0 if $hist < 0;
3130 # Start at the end of the array.
3131 # Stay in while we're still above the ending value.
3132 # Tick back by one each time around the loop.
3133 for ( $i = $#hist ; $i > $end ; $i-- ) {
3135 # Print the command unless it has no arguments.
3136 print $OUT "$i: ", $hist[$i], "\n"
3137 unless $hist[$i] =~ /^.?$/;
3142 =head4 C<man, doc, perldoc> - look up documentation
3144 Just calls C<runman()> to print the appropriate document.
3148 # man, perldoc, doc - show manual pages.
3149 $cmd =~ /^(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?$/ && do {
3156 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3157 the bottom of the loop.
3161 # p - print (no args): print $_.
3162 $cmd =~ s/^p$/print {\$DB::OUT} \$_/;
3164 # p - print the given expression.
3165 $cmd =~ s/^p\b/print {\$DB::OUT} /;
3167 =head4 C<=> - define command alias
3169 Manipulates C<%alias> to add or list command aliases.
3173 # = - set up a command alias.
3174 $cmd =~ s/^=\s*// && do {
3176 if ( length $cmd == 0 ) {
3178 # No args, get current aliases.
3179 @keys = sort keys %alias;
3181 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3183 # Creating a new alias. $k is alias name, $v is
3186 # can't use $_ or kill //g state
3187 for my $x ( $k, $v ) {
3189 # Escape "alarm" characters.
3193 # Substitute key for value, using alarm chars
3194 # as separators (which is why we escaped them in
3196 $alias{$k} = "s\a$k\a$v\a";
3198 # Turn off standard warn and die behavior.
3199 local $SIG{__DIE__};
3200 local $SIG{__WARN__};
3203 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3205 # Nope. Bad alias. Say so and get out.
3206 print $OUT "Can't alias $k to $v: $@\n";
3211 # We'll only list the new one.
3213 } ## end elsif (my ($k, $v) = ($cmd...
3215 # The argument is the alias to list.
3223 # Messy metaquoting: Trim the substiution code off.
3224 # We use control-G as the delimiter because it's not
3225 # likely to appear in the alias.
3226 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3229 print $OUT "$k\t= $1\n";
3231 elsif ( defined $alias{$k} ) {
3233 # Couldn't trim it off; just print the alias code.
3234 print $OUT "$k\t$alias{$k}\n";
3239 print "No alias for $k\n";
3241 } ## end for my $k (@keys)
3245 =head4 C<source> - read commands from a file.
3247 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3252 # source - read commands from a file (or pipe!) and execute.
3253 $cmd =~ /^source\s+(.*\S)/ && do {
3254 if ( open my $fh, $1 ) {
3256 # Opened OK; stick it in the list of file handles.
3262 &warn("Can't execute `$1': $!\n");
3267 =head4 C<save> - send current history to a file
3269 Takes the complete history, (not the shrunken version you see with C<H>),
3270 and saves it to the given filename, so it can be replayed using C<source>.
3272 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3276 # save source - write commands to a file for later use
3277 $cmd =~ /^save\s*(.*)$/ && do {
3278 my $file = $1 || '.perl5dbrc'; # default?
3279 if ( open my $fh, "> $file" ) {
3281 # chomp to remove extraneous newlines from source'd files
3282 chomp( my @truelist =
3283 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3285 print $fh join( "\n", @truelist );
3286 print "commands saved in $file\n";
3289 &warn("Can't save debugger commands in '$1': $!\n");
3294 =head4 C<R> - restart
3296 Restart the debugger session.
3298 =head4 C<rerun> - rerun the current session
3300 Return to any given position in the B<true>-history list
3304 # R - restart execution.
3305 # rerun - controlled restart execution.
3306 $cmd =~ /^(R|rerun\s*(.*))$/ && do {
3307 my @args = ($1 eq 'R' ? restart() : rerun($2));
3309 # Close all non-system fds for a clean restart. A more
3310 # correct method would be to close all fds that were not
3311 # open when the process started, but this seems to be
3312 # hard. See "debugger 'R'estart and open database
3313 # connections" on p5p.
3315 my $max_fd = 1024; # default if POSIX can't be loaded
3316 if (eval { require POSIX }) {
3317 $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX());
3320 if (defined $max_fd) {
3321 foreach ($^F+1 .. $max_fd-1) {
3322 next unless open FD_TO_CLOSE, "<&=$_";
3327 # And run Perl again. We use exec() to keep the
3328 # PID stable (and that way $ini_pids is still valid).
3329 exec(@args) || print $OUT "exec failed: $!\n";
3334 =head4 C<|, ||> - pipe output through the pager.
3336 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3337 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3338 pipe to the pager (restoring the output filehandles if this fails). If this
3339 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3340 set C<$signal>, sending us back into the debugger.
3342 We then trim off the pipe symbols and C<redo> the command loop at the
3343 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3348 # || - run command in the pager, with output to DB::OUT.
3349 $cmd =~ /^\|\|?\s*[^|]/ && do {
3350 if ( $pager =~ /^\|/ ) {
3352 # Default pager is into a pipe. Redirect I/O.
3353 open( SAVEOUT, ">&STDOUT" )
3354 || &warn("Can't save STDOUT");
3355 open( STDOUT, ">&OUT" )
3356 || &warn("Can't redirect STDOUT");
3357 } ## end if ($pager =~ /^\|/)
3360 # Not into a pipe. STDOUT is safe.
3361 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3364 # Fix up environment to record we have less if so.
3367 unless ( $piped = open( OUT, $pager ) ) {
3369 # Couldn't open pipe to pager.
3370 &warn("Can't pipe output to `$pager'");
3371 if ( $pager =~ /^\|/ ) {
3373 # Redirect I/O back again.
3374 open( OUT, ">&STDOUT" ) # XXX: lost message
3375 || &warn("Can't restore DB::OUT");
3376 open( STDOUT, ">&SAVEOUT" )
3377 || &warn("Can't restore STDOUT");
3379 } ## end if ($pager =~ /^\|/)
3382 # Redirect I/O. STDOUT already safe.
3383 open( OUT, ">&STDOUT" ) # XXX: lost message
3384 || &warn("Can't restore DB::OUT");
3387 } ## end unless ($piped = open(OUT,...
3389 # Set up broken-pipe handler if necessary.
3390 $SIG{PIPE} = \&DB::catch
3392 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
3394 # Save current filehandle, unbuffer out, and put it back.
3395 $selected = select(OUT);
3398 # Don't put it back if pager was a pipe.
3399 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
3401 # Trim off the pipe symbols and run the command now.
3402 $cmd =~ s/^\|+\s*//;
3406 =head3 END OF COMMAND PARSING
3408 Anything left in C<$cmd> at this point is a Perl expression that we want to
3409 evaluate. We'll always evaluate in the user's context, and fully qualify
3410 any variables we might want to address in the C<DB> package.
3414 # t - turn trace on.
3415 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3417 # s - single-step. Remember the last command was 's'.
3418 $cmd =~ s/^s\s/\$DB::single = 1;\n/ && do { $laststep = 's' };
3420 # n - single-step, but not into subs. Remember last command
3422 $cmd =~ s/^n\s/\$DB::single = 2;\n/ && do { $laststep = 'n' };
3426 # Make sure the flag that says "the debugger's running" is
3427 # still on, to make sure we get control again.
3428 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3430 # Run *our* eval that executes in the caller's context.
3433 # Turn off the one-time-dump stuff now.
3435 $onetimeDump = undef;
3436 $onetimedumpDepth = undef;
3438 elsif ( $term_pid == $$ ) {
3439 eval { # May run under miniperl, when not available...
3444 # XXX If this is the master pid, print a newline.
3447 } ## end while (($term || &setterm...
3449 =head3 POST-COMMAND PROCESSING
3451 After each command, we check to see if the command output was piped anywhere.
3452 If so, we go through the necessary code to unhook the pipe and go back to
3453 our standard filehandles for input and output.
3459 # At the end of every command:
3462 # Unhook the pipe mechanism now.
3463 if ( $pager =~ /^\|/ ) {
3465 # No error from the child.
3468 # we cannot warn here: the handle is missing --tchrist
3469 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
3471 # most of the $? crud was coping with broken cshisms
3472 # $? is explicitly set to 0, so this never runs.
3474 print SAVEOUT "Pager `$pager' failed: ";
3476 print SAVEOUT "shell returned -1\n";
3479 print SAVEOUT ( $? & 127 )
3480 ? " (SIG#" . ( $? & 127 ) . ")"
3481 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3484 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3488 # Reopen filehandle for our output (if we can) and
3489 # restore STDOUT (if we can).
3490 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3491 open( STDOUT, ">&SAVEOUT" )
3492 || &warn("Can't restore STDOUT");
3494 # Turn off pipe exception handler if necessary.
3495 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
3497 # Will stop ignoring SIGPIPE if done like nohup(1)
3498 # does SIGINT but Perl doesn't give us a choice.
3499 } ## end if ($pager =~ /^\|/)
3502 # Non-piped "pager". Just restore STDOUT.
3503 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3506 # Close filehandle pager was using, restore the normal one
3509 select($selected), $selected = "" unless $selected eq "";
3513 } ## end if ($piped)
3516 =head3 COMMAND LOOP TERMINATION
3518 When commands have finished executing, we come here. If the user closed the
3519 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3520 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3521 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3522 The interpreter will then execute the next line and then return control to us
3527 # No more commands? Quit.
3528 $fall_off_end = 1 unless defined $cmd; # Emulate `q' on EOF
3530 # Evaluate post-prompt commands.
3531 foreach $evalarg (@$post) {
3534 } # if ($single || $signal)
3536 # Put the user's globals back where you found them.
3537 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3541 # The following code may be executed now:
3546 C<sub> is called whenever a subroutine call happens in the program being
3547 debugged. The variable C<$DB::sub> contains the name of the subroutine
3550 The core function of this subroutine is to actually call the sub in the proper
3551 context, capturing its output. This of course causes C<DB::DB> to get called
3552 again, repeating until the subroutine ends and returns control to C<DB::sub>
3553 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3554 return value, and returns its captured copy of the return value as its own
3555 return value. The value then feeds back into the program being debugged as if
3556 C<DB::sub> hadn't been there at all.
3558 C<sub> does all the work of printing the subroutine entry and exit messages
3559 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3560 and also prints the return value if needed (for the C<r> command and if
3561 the 16 bit is set in C<$frame>).
3563 It also tracks the subroutine call depth by saving the current setting of
3564 C<$single> in the C<@stack> package global; if this exceeds the value in
3565 C<$deep>, C<sub> automatically turns on printing of the current depth by
3566 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
3567 of stop/don't stop on entry to subs set as it currently is set.
3569 =head3 C<caller()> support
3571 If C<caller()> is called from the package C<DB>, it provides some
3572 additional data, in the following order:
3578 The package name the sub was in
3580 =item * C<$filename>
3582 The filename it was defined in
3586 The line number it was defined on
3588 =item * C<$subroutine>
3590 The subroutine name; C<(eval)> if an C<eval>().
3594 1 if it has arguments, 0 if not
3596 =item * C<$wantarray>
3598 1 if array context, 0 if scalar context
3600 =item * C<$evaltext>
3602 The C<eval>() text, if any (undefined for C<eval BLOCK>)
3604 =item * C<$is_require>
3606 frame was created by a C<use> or C<require> statement
3610 pragma information; subject to change between versions
3614 pragma information; subject to change between versions
3616 =item * C<@DB::args>
3618 arguments with which the subroutine was invoked
3626 # lock ourselves under threads
3629 # Whether or not the autoloader was running, a scalar to put the
3630 # sub's return value in (if needed), and an array to put the sub's
3631 # return value in (if needed).
3632 my ( $al, $ret, @ret ) = "";
3633 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
3634 print "creating new thread\n";
3637 # If the last ten characters are C'::AUTOLOAD', note we've traced
3638 # into AUTOLOAD for $sub.
3639 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3643 # We stack the stack pointer and then increment it to protect us
3644 # from a situation that might unwind a whole bunch of call frames
3645 # at once. Localizing the stack pointer means that it will automatically
3646 # unwind the same amount when multiple stack frames are unwound.
3647 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3650 $#stack = $stack_depth;
3652 # Save current single-step setting.
3653 $stack[-1] = $single;
3655 # Turn off all flags except single-stepping.
3658 # If we've gotten really deeply recursed, turn on the flag that will
3659 # make us stop with the 'deep recursion' message.
3660 $single |= 4 if $stack_depth == $deep;
3662 # If frame messages are on ...
3664 $frame & 4 # Extended frame entry message
3666 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3668 # Why -1? But it works! :-(
3669 # Because print_trace will call add 1 to it and then call
3670 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3672 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3674 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3676 # standard frame entry message
3680 # Determine the sub's return type,and capture approppriately.
3683 # Called in array context. call sub and capture output.
3684 # DB::DB will recursively get control again if appropriate; we'll come
3685 # back here when the sub is finished.
3688 eval { @ret = &$sub; };
3691 $signal = 1 unless $warnassertions;
3698 # Pop the single-step value back off the stack.
3699 $single |= $stack[ $stack_depth-- ];
3701 # Check for exit trace messages...
3703 $frame & 4 # Extended exit message
3705 print_lineinfo( ' ' x $stack_depth, "out " ),
3706 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3708 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3710 # Standard exit message
3714 # Print the return info if we need to.
3715 if ( $doret eq $stack_depth or $frame & 16 ) {
3717 # Turn off output record separator.
3719 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3721 # Indent if we're printing because of $frame tracing.
3722 print $fh ' ' x $stack_depth if $frame & 16;
3724 # Print the return value.
3725 print $fh "list context return from $sub:\n";
3726 dumpit( $fh, \@ret );
3728 # And don't print it again.
3730 } ## end if ($doret eq $stack_depth...
3731 # And we have to return the return value now.
3733 } ## end if (wantarray)
3741 # Save the value if it's wanted at all.
3746 $signal = 1 unless $warnassertions;
3748 $ret = undef unless defined wantarray;
3751 if ( defined wantarray ) {
3753 # Save the value if it's wanted at all.
3758 # Void return, explicitly.
3764 # Pop the single-step value off the stack.
3765 $single |= $stack[ $stack_depth-- ];
3767 # If we're doing exit messages...
3769 $frame & 4 # Extended messsages
3771 print_lineinfo( ' ' x $stack_depth, "out " ),
3772 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3774 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3780 # If we are supposed to show the return value... same as before.
3781 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
3783 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3784 print $fh ( ' ' x $stack_depth ) if $frame & 16;
3787 ? "scalar context return from $sub: "
3788 : "void context return from $sub\n"
3790 dumpit( $fh, $ret ) if defined wantarray;
3792 } ## end if ($doret eq $stack_depth...
3794 # Return the appropriate scalar value.
3796 } ## end else [ if (wantarray)
3799 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
3801 In Perl 5.8.0, there was a major realignment of the commands and what they did,
3802 Most of the changes were to systematize the command structure and to eliminate
3803 commands that threw away user input without checking.
3805 The following sections describe the code added to make it easy to support
3806 multiple command sets with conflicting command names. This section is a start
3807 at unifying all command processing to make it simpler to develop commands.
3809 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
3810 number, and C<$dbline> (the current line) as arguments.
3812 Support functions in this section which have multiple modes of failure C<die>
3813 on error; the rest simply return a false value.
3815 The user-interface functions (all of the C<cmd_*> functions) just output
3820 The C<%set> hash defines the mapping from command letter to subroutine
3823 C<%set> is a two-level hash, indexed by set name and then by command name.
3824 Note that trying to set the CommandSet to C<foobar> simply results in the
3825 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
3834 'A' => 'pre580_null',
3836 'B' => 'pre580_null',
3837 'd' => 'pre580_null',
3840 'M' => 'pre580_null',
3842 'o' => 'pre580_null',
3848 '<' => 'pre590_prepost',
3849 '<<' => 'pre590_prepost',
3850 '>' => 'pre590_prepost',
3851 '>>' => 'pre590_prepost',
3852 '{' => 'pre590_prepost',
3853 '{{' => 'pre590_prepost',
3857 =head2 C<cmd_wrapper()> (API)
3859 C<cmd_wrapper()> allows the debugger to switch command sets
3860 depending on the value of the C<CommandSet> option.
3862 It tries to look up the command in the C<%set> package-level I<lexical>
3863 (which means external entities can't fiddle with it) and create the name of
3864 the sub to call based on the value found in the hash (if it's there). I<All>
3865 of the commands to be handled in a set have to be added to C<%set>; if they
3866 aren't found, the 5.8.0 equivalent is called (if there is one).
3868 This code uses symbolic references.
3875 my $dblineno = shift;
3877 # Assemble the command subroutine's name by looking up the
3878 # command set and command name in %set. If we can't find it,
3879 # default to the older version of the command.
3881 . ( $set{$CommandSet}{$cmd}
3882 || ( $cmd =~ /^[<>{]+/o ? 'prepost' : $cmd ) );
3884 # Call the command subroutine, call it by name.
3885 return &$call( $cmd, $line, $dblineno );
3886 } ## end sub cmd_wrapper
3888 =head3 C<cmd_a> (command)
3890 The C<a> command handles pre-execution actions. These are associated with a
3891 particular line, so they're stored in C<%dbline>. We default to the current
3892 line if none is specified.
3898 my $line = shift || ''; # [.|line] expr
3901 # If it's dot (here), or not all digits, use the current line.
3902 $line =~ s/^(\.|(?:[^\d]))/$dbline/;
3904 # Should be a line number followed by an expression.
3905 if ( $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
3906 my ( $lineno, $expr ) = ( $1, $2 );
3908 # If we have an expression ...
3909 if ( length $expr ) {
3911 # ... but the line isn't breakable, complain.
3912 if ( $dbline[$lineno] == 0 ) {
3914 "Line $lineno($dbline[$lineno]) does not have an action?\n";
3918 # It's executable. Record that the line has an action.
3919 $had_breakpoints{$filename} |= 2;
3921 # Remove any action, temp breakpoint, etc.
3922 $dbline{$lineno} =~ s/\0[^\0]*//;
3924 # Add the action to the line.
3925 $dbline{$lineno} .= "\0" . action($expr);
3927 } ## end if (length $expr)
3928 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
3933 "Adding an action requires an optional lineno and an expression\n"
3938 =head3 C<cmd_A> (command)
3940 Delete actions. Similar to above, except the delete code is in a separate
3941 subroutine, C<delete_action>.
3947 my $line = shift || '';
3951 $line =~ s/^\./$dbline/;
3953 # Call delete_action with a null param to delete them all.
3954 # The '1' forces the eval to be true. It'll be false only
3955 # if delete_action blows up for some reason, in which case
3956 # we print $@ and get out.
3957 if ( $line eq '*' ) {
3958 eval { &delete_action(); 1 } or print $OUT $@ and return;
3961 # There's a real line number. Pass it to delete_action.
3962 # Error trapping is as above.
3963 elsif ( $line =~ /^(\S.*)/ ) {
3964 eval { &delete_action($1); 1 } or print $OUT $@ and return;
3967 # Swing and a miss. Bad syntax.
3970 "Deleting an action requires a line number, or '*' for all\n" ; # hint
3974 =head3 C<delete_action> (API)
3976 C<delete_action> accepts either a line number or C<undef>. If a line number
3977 is specified, we check for the line being executable (if it's not, it
3978 couldn't have had an action). If it is, we just take the action off (this
3979 will get any kind of an action, including breakpoints).
3985 if ( defined($i) ) {
3988 die "Line $i has no action .\n" if $dbline[$i] == 0;
3990 # Nuke whatever's there.
3991 $dbline{$i} =~ s/\0[^\0]*//; # \^a
3992 delete $dbline{$i} if $dbline{$i} eq '';
3995 print $OUT "Deleting all actions...\n";
3996 for my $file ( keys %had_breakpoints ) {
3997 local *dbline = $main::{ '_<' . $file };
4000 for ( $i = 1 ; $i <= $max ; $i++ ) {
4001 if ( defined $dbline{$i} ) {
4002 $dbline{$i} =~ s/\0[^\0]*//;
4003 delete $dbline{$i} if $dbline{$i} eq '';
4005 unless ( $had_breakpoints{$file} &= ~2 ) {
4006 delete $had_breakpoints{$file};
4008 } ## end for ($i = 1 ; $i <= $max...
4009 } ## end for my $file (keys %had_breakpoints)
4010 } ## end else [ if (defined($i))
4011 } ## end sub delete_action
4013 =head3 C<cmd_b> (command)
4015 Set breakpoints. Since breakpoints can be set in so many places, in so many
4016 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4017 we try to parse the command type, and then shuttle it off to an appropriate
4018 subroutine to actually do the work of setting the breakpoint in the right
4025 my $line = shift; # [.|line] [cond]
4028 # Make . the current line number if it's there..
4029 $line =~ s/^\./$dbline/;
4031 # No line number, no condition. Simple break on current line.
4032 if ( $line =~ /^\s*$/ ) {
4033 &cmd_b_line( $dbline, 1 );
4036 # Break on load for a file.
4037 elsif ( $line =~ /^load\b\s*(.*)/ ) {
4043 # b compile|postpone <some sub> [<condition>]
4044 # The interpreter actually traps this one for us; we just put the
4045 # necessary condition in the %postponed hash.
4046 elsif ( $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4048 # Capture the condition if there is one. Make it true if none.
4049 my $cond = length $3 ? $3 : '1';
4051 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
4052 # if it was 'compile'.
4053 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
4055 # De-Perl4-ify the name - ' separators to ::.
4056 $subname =~ s/\'/::/g;
4058 # Qualify it into the current package unless it's already qualified.
4059 $subname = "${'package'}::" . $subname unless $subname =~ /::/;
4061 # Add main if it starts with ::.
4062 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4064 # Save the break type for this sub.
4065 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
4066 } ## end elsif ($line =~ ...
4068 # b <sub name> [<condition>]
4069 elsif ( $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4073 $cond = length $2 ? $2 : '1';
4074 &cmd_b_sub( $subname, $cond );
4077 # b <line> [<condition>].
4078 elsif ( $line =~ /^(\d*)\s*(.*)/ ) {
4080 # Capture the line. If none, it's the current line.
4081 $line = $1 || $dbline;
4083 # If there's no condition, make it '1'.
4084 $cond = length $2 ? $2 : '1';
4087 &cmd_b_line( $line, $cond );
4090 # Line didn't make sense.
4092 print "confused by line($line)?\n";
4096 =head3 C<break_on_load> (API)
4098 We want to break when this file is loaded. Mark this file in the
4099 C<%break_on_load> hash, and note that it has a breakpoint in
4100 C<%had_breakpoints>.
4106 $break_on_load{$file} = 1;
4107 $had_breakpoints{$file} |= 1;
4110 =head3 C<report_break_on_load> (API)
4112 Gives us an array of filenames that are set to break on load. Note that
4113 only files with break-on-load are in here, so simply showing the keys
4118 sub report_break_on_load {
4119 sort keys %break_on_load;
4122 =head3 C<cmd_b_load> (command)
4124 We take the file passed in and try to find it in C<%INC> (which maps modules
4125 to files they came from). We mark those files for break-on-load via
4126 C<break_on_load> and then report that it was done.
4134 # This is a block because that way we can use a redo inside it
4135 # even without there being any looping structure at all outside it.
4138 # Save short name and full path if found.
4140 push @files, $::INC{$file} if $::INC{$file};
4142 # Tack on .pm and do it again unless there was a '.' in the name
4144 $file .= '.pm', redo unless $file =~ /\./;
4147 # Do the real work here.
4148 break_on_load($_) for @files;
4150 # All the files that have break-on-load breakpoints.
4151 @files = report_break_on_load;
4153 # Normalize for the purposes of our printing this.
4156 print $OUT "Will stop on load of `@files'.\n";
4157 } ## end sub cmd_b_load
4159 =head3 C<$filename_error> (API package global)
4161 Several of the functions we need to implement in the API need to work both
4162 on the current file and on other files. We don't want to duplicate code, so
4163 C<$filename_error> is used to contain the name of the file that's being
4164 worked on (if it's not the current one).
4166 We can now build functions in pairs: the basic function works on the current
4167 file, and uses C<$filename_error> as part of its error message. Since this is
4168 initialized to C<"">, no filename will appear when we are working on the
4171 The second function is a wrapper which does the following:
4177 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4181 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4185 Calls the first function.
4187 The first function works on the I<current> file (i.e., the one we changed to),
4188 and prints C<$filename_error> in the error message (the name of the other file)
4189 if it needs to. When the functions return, C<*dbline> is restored to point
4190 to the actual current file (the one we're executing in) and
4191 C<$filename_error> is restored to C<"">. This restores everything to
4192 the way it was before the second function was called at all.
4194 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4201 $filename_error = '';
4203 =head3 breakable_line(from, to) (API)
4205 The subroutine decides whether or not a line in the current file is breakable.
4206 It walks through C<@dbline> within the range of lines specified, looking for
4207 the first line that is breakable.
4209 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4210 first line I<after> C<$to> that's breakable, if there is one.
4212 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4213 first line I<before> C<$to> that's breakable, if there is one.
4217 sub breakable_line {
4219 my ( $from, $to ) = @_;
4221 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4224 # If there are at least 2 arguments, we're trying to search a range.
4227 # $delta is positive for a forward search, negative for a backward one.
4228 my $delta = $from < $to ? +1 : -1;
4230 # Keep us from running off the ends of the file.
4231 my $limit = $delta > 0 ? $#dbline : 1;
4233 # Clever test. If you're a mathematician, it's obvious why this
4234 # test works. If not:
4235 # If $delta is positive (going forward), $limit will be $#dbline.
4236 # If $to is less than $limit, ($limit - $to) will be positive, times
4237 # $delta of 1 (positive), so the result is > 0 and we should use $to
4238 # as the stopping point.
4240 # If $to is greater than $limit, ($limit - $to) is negative,
4241 # times $delta of 1 (positive), so the result is < 0 and we should
4242 # use $limit ($#dbline) as the stopping point.
4244 # If $delta is negative (going backward), $limit will be 1.
4245 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4246 # (negative) so the result is > 0, and we use $to as the stopping
4249 # If $to is less than zero, ($limit - $to) will be positive,
4250 # times $delta of -1 (negative), so the result is not > 0, and
4251 # we use $limit (1) as the stopping point.
4253 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4254 # (negative), still giving zero; the result is not > 0, and
4255 # we use $limit (1) as the stopping point.
4257 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4258 # (negative), giving a positive (>0) value, so we'll set $limit to
4261 $limit = $to if ( $limit - $to ) * $delta > 0;
4263 # The real search loop.
4264 # $i starts at $from (the point we want to start searching from).
4265 # We move through @dbline in the appropriate direction (determined
4266 # by $delta: either -1 (back) or +1 (ahead).
4267 # We stay in as long as we haven't hit an executable line
4268 # ($dbline[$i] == 0 means not executable) and we haven't reached
4269 # the limit yet (test similar to the above).
4270 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4272 } ## end if (@_ >= 2)
4274 # If $i points to a line that is executable, return that.
4275 return $i unless $dbline[$i] == 0;
4277 # Format the message and print it: no breakable lines in range.
4278 my ( $pl, $upto ) = ( '', '' );
4279 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4281 # If there's a filename in filename_error, we'll see it.
4283 die "Line$pl $from$upto$filename_error not breakable\n";
4284 } ## end sub breakable_line
4286 =head3 breakable_line_in_filename(file, from, to) (API)
4288 Like C<breakable_line>, but look in another file.
4292 sub breakable_line_in_filename {
4294 # Capture the file name.
4297 # Swap the magic line array over there temporarily.
4298 local *dbline = $main::{ '_<' . $f };
4300 # If there's an error, it's in this other file.
4301 local $filename_error = " of `$f'";
4303 # Find the breakable line.
4306 # *dbline and $filename_error get restored when this block ends.
4308 } ## end sub breakable_line_in_filename
4310 =head3 break_on_line(lineno, [condition]) (API)
4312 Adds a breakpoint with the specified condition (or 1 if no condition was
4313 specified) to the specified line. Dies if it can't.
4318 my ( $i, $cond ) = @_;
4320 # Always true if no condition supplied.
4321 $cond = 1 unless @_ >= 2;
4327 # Woops, not a breakable line. $filename_error allows us to say
4328 # if it was in a different file.
4329 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4331 # Mark this file as having breakpoints in it.
4332 $had_breakpoints{$filename} |= 1;
4334 # If there is an action or condition here already ...
4335 if ( $dbline{$i} ) {
4337 # ... swap this condition for the existing one.
4338 $dbline{$i} =~ s/^[^\0]*/$cond/;
4342 # Nothing here - just add the condition.
4343 $dbline{$i} = $cond;
4345 } ## end sub break_on_line
4347 =head3 cmd_b_line(line, [condition]) (command)
4349 Wrapper for C<break_on_line>. Prints the failure message if it
4355 eval { break_on_line(@_); 1 } or do {
4357 print $OUT $@ and return;
4359 } ## end sub cmd_b_line
4361 =head3 break_on_filename_line(file, line, [condition]) (API)
4363 Switches to the file specified and then calls C<break_on_line> to set
4368 sub break_on_filename_line {
4369 my ( $f, $i, $cond ) = @_;
4371 # Always true if condition left off.
4372 $cond = 1 unless @_ >= 3;
4374 # Switch the magical hash temporarily.
4375 local *dbline = $main::{ '_<' . $f };
4377 # Localize the variables that break_on_line uses to make its message.
4378 local $filename_error = " of `$f'";
4379 local $filename = $f;
4381 # Add the breakpoint.
4382 break_on_line( $i, $cond );
4383 } ## end sub break_on_filename_line
4385 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4387 Switch to another file, search the range of lines specified for an
4388 executable one, and put a breakpoint on the first one you find.
4392 sub break_on_filename_line_range {
4393 my ( $f, $from, $to, $cond ) = @_;
4395 # Find a breakable line if there is one.
4396 my $i = breakable_line_in_filename( $f, $from, $to );
4398 # Always true if missing.
4399 $cond = 1 unless @_ >= 3;
4401 # Add the breakpoint.
4402 break_on_filename_line( $f, $i, $cond );
4403 } ## end sub break_on_filename_line_range
4405 =head3 subroutine_filename_lines(subname, [condition]) (API)
4407 Search for a subroutine within a given file. The condition is ignored.
4408 Uses C<find_sub> to locate the desired subroutine.
4412 sub subroutine_filename_lines {
4413 my ( $subname, $cond ) = @_;
4415 # Returned value from find_sub() is fullpathname:startline-endline.
4416 # The match creates the list (fullpathname, start, end). Falling off
4417 # the end of the subroutine returns this implicitly.
4418 find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/;
4419 } ## end sub subroutine_filename_lines
4421 =head3 break_subroutine(subname) (API)
4423 Places a break on the first line possible in the specified subroutine. Uses
4424 C<subroutine_filename_lines> to find the subroutine, and
4425 C<break_on_filename_line_range> to place the break.
4429 sub break_subroutine {
4430 my $subname = shift;
4432 # Get filename, start, and end.
4433 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
4434 or die "Subroutine $subname not found.\n";
4436 # Null condition changes to '1' (always true).
4437 $cond = 1 unless @_ >= 2;
4439 # Put a break the first place possible in the range of lines
4440 # that make up this subroutine.
4441 break_on_filename_line_range( $file, $s, $e, @_ );
4442 } ## end sub break_subroutine
4444 =head3 cmd_b_sub(subname, [condition]) (command)
4446 We take the incoming subroutine name and fully-qualify it as best we can.
4450 =item 1. If it's already fully-qualified, leave it alone.
4452 =item 2. Try putting it in the current package.
4454 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
4456 =item 4. If it starts with '::', put it in 'main::'.
4460 After all this cleanup, we call C<break_subroutine> to try to set the
4466 my ( $subname, $cond ) = @_;
4468 # Add always-true condition if we have none.
4469 $cond = 1 unless @_ >= 2;
4471 # If the subname isn't a code reference, qualify it so that
4472 # break_subroutine() will work right.
4473 unless ( ref $subname eq 'CODE' ) {
4476 $subname =~ s/\'/::/g;
4479 # Put it in this package unless it's already qualified.
4480 $subname = "${'package'}::" . $subname
4481 unless $subname =~ /::/;
4483 # Requalify it into CORE::GLOBAL if qualifying it into this
4484 # package resulted in its not being defined, but only do so
4485 # if it really is in CORE::GLOBAL.
4486 $subname = "CORE::GLOBAL::$s"
4487 if not defined &$subname
4489 and defined &{"CORE::GLOBAL::$s"};
4491 # Put it in package 'main' if it has a leading ::.
4492 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4494 } ## end unless (ref $subname eq 'CODE')
4496 # Try to set the breakpoint.
4497 eval { break_subroutine( $subname, $cond ); 1 } or do {
4499 print $OUT $@ and return;
4501 } ## end sub cmd_b_sub
4503 =head3 C<cmd_B> - delete breakpoint(s) (command)
4505 The command mostly parses the command line and tries to turn the argument
4506 into a line spec. If it can't, it uses the current line. It then calls
4507 C<delete_breakpoint> to actually do the work.
4509 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
4510 thereby deleting all the breakpoints.
4517 # No line spec? Use dbline.
4518 # If there is one, use it if it's non-zero, or wipe it out if it is.
4519 my $line = ( $_[0] =~ /^\./ ) ? $dbline : shift || '';
4522 # If the line was dot, make the line the current one.
4523 $line =~ s/^\./$dbline/;
4525 # If it's * we're deleting all the breakpoints.
4526 if ( $line eq '*' ) {
4527 eval { &delete_breakpoint(); 1 } or print $OUT $@ and return;
4530 # If there is a line spec, delete the breakpoint on that line.
4531 elsif ( $line =~ /^(\S.*)/ ) {
4532 eval { &delete_breakpoint( $line || $dbline ); 1 } or do {
4534 print $OUT $@ and return;
4536 } ## end elsif ($line =~ /^(\S.*)/)
4541 "Deleting a breakpoint requires a line number, or '*' for all\n"
4546 =head3 delete_breakpoint([line]) (API)
4548 This actually does the work of deleting either a single breakpoint, or all
4551 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
4552 just drop out with a message saying so. If it is, we remove the condition
4553 part of the 'condition\0action' that says there's a breakpoint here. If,
4554 after we've done that, there's nothing left, we delete the corresponding
4555 line in C<%dbline> to signal that no action needs to be taken for this line.
4557 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
4558 which lists all currently-loaded files which have breakpoints. We then look
4559 at each line in each of these files, temporarily switching the C<%dbline>
4560 and C<@dbline> structures to point to the files in question, and do what
4561 we did in the single line case: delete the condition in C<@dbline>, and
4562 delete the key in C<%dbline> if nothing's left.
4564 We then wholesale delete C<%postponed>, C<%postponed_file>, and
4565 C<%break_on_load>, because these structures contain breakpoints for files
4566 and code that haven't been loaded yet. We can just kill these off because there
4567 are no magical debugger structures associated with them.
4571 sub delete_breakpoint {
4574 # If we got a line, delete just that one.
4575 if ( defined($i) ) {
4577 # Woops. This line wasn't breakable at all.
4578 die "Line $i not breakable.\n" if $dbline[$i] == 0;
4580 # Kill the condition, but leave any action.
4581 $dbline{$i} =~ s/^[^\0]*//;
4583 # Remove the entry entirely if there's no action left.
4584 delete $dbline{$i} if $dbline{$i} eq '';
4587 # No line; delete them all.
4589 print $OUT "Deleting all breakpoints...\n";
4591 # %had_breakpoints lists every file that had at least one
4593 for my $file ( keys %had_breakpoints ) {
4595 # Switch to the desired file temporarily.
4596 local *dbline = $main::{ '_<' . $file };
4601 # For all lines in this file ...
4602 for ( $i = 1 ; $i <= $max ; $i++ ) {
4604 # If there's a breakpoint or action on this line ...
4605 if ( defined $dbline{$i} ) {
4607 # ... remove the breakpoint.
4608 $dbline{$i} =~ s/^[^\0]+//;
4609 if ( $dbline{$i} =~ s/^\0?$// ) {
4611 # Remove the entry altogether if no action is there.
4614 } ## end if (defined $dbline{$i...
4615 } ## end for ($i = 1 ; $i <= $max...
4617 # If, after we turn off the "there were breakpoints in this file"
4618 # bit, the entry in %had_breakpoints for this file is zero,
4619 # we should remove this file from the hash.
4620 if ( not $had_breakpoints{$file} &= ~1 ) {
4621 delete $had_breakpoints{$file};
4623 } ## end for my $file (keys %had_breakpoints)
4625 # Kill off all the other breakpoints that are waiting for files that
4626 # haven't been loaded yet.
4628 undef %postponed_file;
4629 undef %break_on_load;
4630 } ## end else [ if (defined($i))
4631 } ## end sub delete_breakpoint
4633 =head3 cmd_stop (command)
4635 This is meant to be part of the new command API, but it isn't called or used
4636 anywhere else in the debugger. XXX It is probably meant for use in development
4641 sub cmd_stop { # As on ^C, but not signal-safy.
4645 =head3 C<cmd_e> - threads
4647 Display the current thread id:
4651 This could be how (when implemented) to send commands to this thread id (e cmd)
4652 or that thread id (e tid cmd).
4659 unless (exists($INC{'threads.pm'})) {
4660 print "threads not loaded($ENV{PERL5DB_THREADED})
4661 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4663 my $tid = threads->self->tid;
4664 print "thread id: $tid\n";
4668 =head3 C<cmd_E> - list of thread ids
4670 Display the list of available thread ids:
4674 This could be used (when implemented) to send commands to all threads (E cmd).
4681 unless (exists($INC{'threads.pm'})) {
4682 print "threads not loaded($ENV{PERL5DB_THREADED})
4683 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4685 my $tid = threads->self->tid;
4686 print "thread ids: ".join(', ',
4687 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
4692 =head3 C<cmd_h> - help command (command)
4694 Does the work of either
4700 Showing all the debugger help
4704 Showing help for a specific command
4713 # If we have no operand, assume null.
4714 my $line = shift || '';
4716 # 'h h'. Print the long-format help.
4717 if ( $line =~ /^h\s*/ ) {
4721 # 'h <something>'. Search for the command and print only its help.
4722 elsif ( $line =~ /^(\S.*)$/ ) {
4724 # support long commands; otherwise bogus errors
4725 # happen when you ask for h on <CR> for example
4726 my $asked = $1; # the command requested
4727 # (for proper error message)
4729 my $qasked = quotemeta($asked); # for searching; we don't
4730 # want to use it as a pattern.
4731 # XXX: finds CR but not <CR>
4733 # Search the help string for the command.
4735 $help =~ /^ # Start of a line
4737 (?:[IB]<) # Optional markup
4738 $qasked # The requested command
4743 # It's there; pull it out and print it.
4747 (?:[IB]<) # Optional markup
4748 $qasked # The command
4749 ([\s\S]*?) # Description line(s)
4750 \n) # End of last description line
4751 (?!\s) # Next line not starting with
4760 # Not found; not a debugger command.
4762 print_help("B<$asked> is not a debugger command.\n");
4764 } ## end elsif ($line =~ /^(\S.*)$/)
4766 # 'h' - print the summary help.
4768 print_help($summary);
4772 =head3 C<cmd_i> - inheritance display
4774 Display the (nested) parentage of the module or object given.
4781 eval { require Class::ISA };
4783 &warn( $@ =~ /locate/
4784 ? "Class::ISA module not found - please install\n"
4789 foreach my $isa ( split( /\s+/, $line ) ) {
4795 map { # snaffled unceremoniously from Class::ISA
4798 defined( ${"$_\::VERSION"} )
4799 ? ' ' . ${"$_\::VERSION"}
4801 } Class::ISA::self_and_super_path(ref($isa) || $isa)
4808 =head3 C<cmd_l> - list lines (command)
4810 Most of the command is taken up with transforming all the different line
4811 specification syntaxes into 'start-stop'. After that is done, the command
4812 runs a loop over C<@dbline> for the specified range of lines. It handles
4813 the printing of each line and any markers (C<==E<gt>> for current line,
4814 C<b> for break on this line, C<a> for action on this line, C<:> for this
4817 We save the last line listed in the C<$start> global for further listing
4823 my $current_line = $line;
4827 # If this is '-something', delete any spaces after the dash.
4828 $line =~ s/^-\s*$/-/;
4830 # If the line is '$something', assume this is a scalar containing a
4832 if ( $line =~ /^(\$.*)/s ) {
4834 # Set up for DB::eval() - evaluate in *user* context.
4839 # Ooops. Bad scalar.
4840 print( $OUT "Error: $@\n" ), next CMD if $@;
4842 # Good scalar. If it's a reference, find what it points to.
4844 print( $OUT "Interpreted as: $1 $s\n" );
4847 # Call self recursively to really do the command.
4849 } ## end if ($line =~ /^(\$.*)/s)
4851 # l name. Try to find a sub by that name.
4852 elsif ( $line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s ) {
4853 my $s = $subname = $1;
4856 $subname =~ s/\'/::/;
4858 # Put it in this package unless it starts with ::.
4859 $subname = $package . "::" . $subname unless $subname =~ /::/;
4861 # Put it in CORE::GLOBAL if t doesn't start with :: and
4862 # it doesn't live in this package and it lives in CORE::GLOBAL.
4863 $subname = "CORE::GLOBAL::$s"
4864 if not defined &$subname
4866 and defined &{"CORE::GLOBAL::$s"};
4868 # Put leading '::' names into 'main::'.
4869 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4871 # Get name:start-stop from find_sub, and break this up at
4873 @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
4875 # Pull off start-stop.
4876 $subrange = pop @pieces;
4878 # If the name contained colons, the split broke it up.
4879 # Put it back together.
4880 $file = join( ':', @pieces );
4882 # If we're not in that file, switch over to it.
4883 if ( $file ne $filename ) {
4884 print $OUT "Switching to file '$file'.\n"
4885 unless $slave_editor;
4887 # Switch debugger's magic structures.
4888 *dbline = $main::{ '_<' . $file };
4891 } ## end if ($file ne $filename)
4893 # Subrange is 'start-stop'. If this is less than a window full,
4894 # swap it to 'start+', which will list a window from the start point.
4896 if ( eval($subrange) < -$window ) {
4897 $subrange =~ s/-.*/+/;
4900 # Call self recursively to list the range.
4902 &cmd_l( 'l', $subrange );
4903 } ## end if ($subrange)
4907 print $OUT "Subroutine $subname not found.\n";
4909 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s)
4912 elsif ( $line =~ /^\s*$/ ) {
4914 # Compute new range to list.
4915 $incr = $window - 1;
4916 $line = $start . '-' . ( $start + $incr );
4919 &cmd_l( 'l', $line );
4922 # l [start]+number_of_lines
4923 elsif ( $line =~ /^(\d*)\+(\d*)$/ ) {
4925 # Don't reset start for 'l +nnn'.
4928 # Increment for list. Use window size if not specified.
4929 # (Allows 'l +' to work.)
4931 $incr = $window - 1 unless $incr;
4933 # Create a line range we'll understand, and recurse to do it.
4934 $line = $start . '-' . ( $start + $incr );
4935 &cmd_l( 'l', $line );
4936 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/)
4938 # l start-stop or l start,stop
4939 elsif ( $line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/ ) {
4941 # Determine end point; use end of file if not specified.
4942 $end = ( !defined $2 ) ? $max : ( $4 ? $4 : $2 );
4944 # Go on to the end, and then stop.
4945 $end = $max if $end > $max;
4947 # Determine start line.
4949 $i = $line if $i eq '.';
4953 # If we're running under a slave editor, force it to show the lines.
4954 if ($slave_editor) {
4955 print $OUT "\032\032$filename:$i:0\n";
4959 # We're doing it ourselves. We want to show the line and special
4961 # - the current line in execution
4962 # - whether a line is breakable or not
4963 # - whether a line has a break or not
4964 # - whether a line has an action or not
4966 for ( ; $i <= $end ; $i++ ) {
4968 # Check for breakpoints and actions.
4969 my ( $stop, $action );
4970 ( $stop, $action ) = split( /\0/, $dbline{$i} )
4973 # ==> if this is the current line in execution,
4974 # : if it's breakable.
4976 ( $i == $current_line and $filename eq $filename_ini )
4978 : ( $dbline[$i] + 0 ? ':' : ' ' );
4980 # Add break and action indicators.
4981 $arrow .= 'b' if $stop;
4982 $arrow .= 'a' if $action;
4985 print $OUT "$i$arrow\t", $dbline[$i];
4987 # Move on to the next line. Drop out on an interrupt.
4988 $i++, last if $signal;
4989 } ## end for (; $i <= $end ; $i++)
4991 # Line the prompt up; print a newline if the last line listed
4992 # didn't have a newline.
4993 print $OUT "\n" unless $dbline[ $i - 1 ] =~ /\n$/;
4994 } ## end else [ if ($slave_editor)
4996 # Save the point we last listed to in case another relative 'l'
4997 # command is desired. Don't let it run off the end.
4999 $start = $max if $start > $max;
5000 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/)
5003 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5005 To list breakpoints, the command has to look determine where all of them are
5006 first. It starts a C<%had_breakpoints>, which tells us what all files have
5007 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5008 magic source and breakpoint data structures) to the file, and then look
5009 through C<%dbline> for lines with breakpoints and/or actions, listing them
5010 out. We look through C<%postponed> not-yet-compiled subroutines that have
5011 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5012 that have breakpoints.
5014 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5021 # If no argument, list everything. Pre-5.8.0 version always lists
5023 my $arg = shift || 'abw';
5024 $arg = 'abw' unless $CommandSet eq '580'; # sigh...
5026 # See what is wanted.
5027 my $action_wanted = ( $arg =~ /a/ ) ? 1 : 0;
5028 my $break_wanted = ( $arg =~ /b/ ) ? 1 : 0;
5029 my $watch_wanted = ( $arg =~ /w/ ) ? 1 : 0;
5031 # Breaks and actions are found together, so we look in the same place
5033 if ( $break_wanted or $action_wanted ) {
5035 # Look in all the files with breakpoints...
5036 for my $file ( keys %had_breakpoints ) {
5038 # Temporary switch to this file.
5039 local *dbline = $main::{ '_<' . $file };
5041 # Set up to look through the whole file.
5043 my $was; # Flag: did we print something
5046 # For each line in the file ...
5047 for ( $i = 1 ; $i <= $max ; $i++ ) {
5049 # We've got something on this line.
5050 if ( defined $dbline{$i} ) {
5052 # Print the header if we haven't.
5053 print $OUT "$file:\n" unless $was++;
5056 print $OUT " $i:\t", $dbline[$i];
5058 # Pull out the condition and the action.
5059 ( $stop, $action ) = split( /\0/, $dbline{$i} );
5061 # Print the break if there is one and it's wanted.
5062 print $OUT " break if (", $stop, ")\n"
5066 # Print the action if there is one and it's wanted.
5067 print $OUT " action: ", $action, "\n"
5071 # Quit if the user hit interrupt.
5073 } ## end if (defined $dbline{$i...
5074 } ## end for ($i = 1 ; $i <= $max...
5075 } ## end for my $file (keys %had_breakpoints)
5076 } ## end if ($break_wanted or $action_wanted)
5078 # Look for breaks in not-yet-compiled subs:
5079 if ( %postponed and $break_wanted ) {
5080 print $OUT "Postponed breakpoints in subroutines:\n";
5082 for $subname ( keys %postponed ) {
5083 print $OUT " $subname\t$postponed{$subname}\n";
5086 } ## end if (%postponed and $break_wanted)
5088 # Find files that have not-yet-loaded breaks:
5089 my @have = map { # Combined keys
5090 keys %{ $postponed_file{$_} }
5091 } keys %postponed_file;
5093 # If there are any, list them.
5094 if ( @have and ( $break_wanted or $action_wanted ) ) {
5095 print $OUT "Postponed breakpoints in files:\n";
5096 my ( $file, $line );
5098 for $file ( keys %postponed_file ) {
5099 my $db = $postponed_file{$file};
5100 print $OUT " $file:\n";
5101 for $line ( sort { $a <=> $b } keys %$db ) {
5102 print $OUT " $line:\n";
5103 my ( $stop, $action ) = split( /\0/, $$db{$line} );
5104 print $OUT " break if (", $stop, ")\n"
5107 print $OUT " action: ", $action, "\n"
5111 } ## end for $line (sort { $a <=>...
5113 } ## end for $file (keys %postponed_file)
5114 } ## end if (@have and ($break_wanted...
5115 if ( %break_on_load and $break_wanted ) {
5116 print $OUT "Breakpoints on load:\n";
5118 for $file ( keys %break_on_load ) {
5119 print $OUT " $file\n";
5122 } ## end if (%break_on_load and...
5123 if ($watch_wanted) {
5125 print $OUT "Watch-expressions:\n" if @to_watch;
5126 for my $expr (@to_watch) {
5127 print $OUT " $expr\n";
5130 } ## end if ($trace & 2)
5131 } ## end if ($watch_wanted)
5134 =head3 C<cmd_M> - list modules (command)
5136 Just call C<list_modules>.
5144 =head3 C<cmd_o> - options (command)
5146 If this is just C<o> by itself, we list the current settings via
5147 C<dump_option>. If there's a nonblank value following it, we pass that on to
5148 C<parse_options> for processing.
5154 my $opt = shift || ''; # opt[=val]
5156 # Nonblank. Try to parse and process.
5157 if ( $opt =~ /^(\S.*)/ ) {
5161 # Blank. List the current option settings.
5169 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5171 Advises the user that the O command has been renamed.
5176 print $OUT "The old O command is now the o command.\n"; # hint
5177 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5178 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5181 =head3 C<cmd_v> - view window (command)
5183 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5184 move back a few lines to list the selected line in context. Uses C<cmd_l>
5185 to do the actual listing after figuring out the range of line to request.
5193 # Extract the line to list around. (Astute readers will have noted that
5194 # this pattern will match whether or not a numeric line is specified,
5195 # which means that we'll always enter this loop (though a non-numeric
5196 # argument results in no action at all)).
5197 if ( $line =~ /^(\d*)$/ ) {
5199 # Total number of lines to list (a windowful).
5200 $incr = $window - 1;
5202 # Set the start to the argument given (if there was one).
5205 # Back up by the context amount.
5208 # Put together a linespec that cmd_l will like.
5209 $line = $start . '-' . ( $start + $incr );
5212 &cmd_l( 'l', $line );
5213 } ## end if ($line =~ /^(\d*)$/)
5216 =head3 C<cmd_w> - add a watch expression (command)
5218 The 5.8 version of this command adds a watch expression if one is specified;
5219 it does nothing if entered with no operands.
5221 We extract the expression, save it, evaluate it in the user's context, and
5222 save the value. We'll re-evaluate it each time the debugger passes a line,
5223 and will stop (see the code at the top of the command loop) if the value
5224 of any of the expressions changes.
5231 # Null expression if no arguments.
5232 my $expr = shift || '';
5234 # If expression is not null ...
5235 if ( $expr =~ /^(\S.*)/ ) {
5238 push @to_watch, $expr;
5240 # Parameterize DB::eval and call it to get the expression's value
5241 # in the user's context. This version can handle expressions which
5242 # return a list value.
5244 my ($val) = join( ' ', &eval );
5245 $val = ( defined $val ) ? "'$val'" : 'undef';
5247 # Save the current value of the expression.
5248 push @old_watch, $val;
5250 # We are now watching expressions.
5252 } ## end if ($expr =~ /^(\S.*)/)
5254 # You have to give one to get one.
5256 print $OUT "Adding a watch-expression requires an expression\n"; # hint
5260 =head3 C<cmd_W> - delete watch expressions (command)
5262 This command accepts either a watch expression to be removed from the list
5263 of watch expressions, or C<*> to delete them all.
5265 If C<*> is specified, we simply empty the watch expression list and the
5266 watch expression value list. We also turn off the bit that says we've got
5269 If an expression (or partial expression) is specified, we pattern-match
5270 through the expressions and remove the ones that match. We also discard
5271 the corresponding values. If no watch expressions are left, we turn off
5272 the I<watching expressions> bit.
5278 my $expr = shift || '';
5281 if ( $expr eq '*' ) {
5286 print $OUT "Deleting all watch expressions ...\n";
5289 @to_watch = @old_watch = ();
5292 # Delete one of them.
5293 elsif ( $expr =~ /^(\S.*)/ ) {
5295 # Where we are in the list.
5298 # For each expression ...
5299 foreach (@to_watch) {
5300 my $val = $to_watch[$i_cnt];
5302 # Does this one match the command argument?
5303 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
5304 # Yes. Turn it off, and its value too.
5305 splice( @to_watch, $i_cnt, 1 );
5306 splice( @old_watch, $i_cnt, 1 );
5309 } ## end foreach (@to_watch)
5311 # We don't bother to turn watching off because
5312 # a) we don't want to stop calling watchfunction() it it exists
5313 # b) foreach over a null list doesn't do anything anyway
5315 } ## end elsif ($expr =~ /^(\S.*)/)
5317 # No command arguments entered.
5320 "Deleting a watch-expression requires an expression, or '*' for all\n"
5325 ### END of the API section
5327 =head1 SUPPORT ROUTINES
5329 These are general support routines that are used in a number of places
5330 throughout the debugger.
5336 Something to do with assertions
5343 unless ($ini_assertion) {
5344 print $OUT "Assertions not supported in this Perl interpreter\n";
5346 if ( $cmd =~ /^.\b\s*([+-]?)\s*(~?)\s*(\w+(\s*\|\s*\w+)*)\s*$/ ) {
5347 my ( $how, $neg, $flags ) = ( $1, $2, $3 );
5348 my $acu = parse_DollarCaretP_flags($flags);
5349 if ( defined $acu ) {
5350 $acu = ~$acu if $neg;
5351 if ( $how eq '+' ) { $^P |= $acu }
5352 elsif ( $how eq '-' ) { $^P &= ~$acu }
5356 # else { print $OUT "undefined acu\n" }
5358 my $expanded = expand_DollarCaretP_flags($^P);
5359 print $OUT "Internal Perl debugger flags:\n\$^P=$expanded\n";
5366 save() saves the user's versions of globals that would mess us up in C<@saved>,
5367 and installs the versions we like better.
5373 # Save eval failure, command failure, extended OS error, output field
5374 # separator, input record separator, output record separator and
5375 # the warning setting.
5376 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
5378 $, = ""; # output field separator is null string
5379 $/ = "\n"; # input record separator is newline
5380 $\ = ""; # output record separator is null string
5381 $^W = 0; # warnings are off
5384 =head2 C<print_lineinfo> - show where we are now
5386 print_lineinfo prints whatever it is that it is handed; it prints it to the
5387 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
5388 us to feed line information to a slave editor without messing up the
5393 sub print_lineinfo {
5395 # Make the terminal sensible if we're not the primary debugger.
5396 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
5400 } ## end sub print_lineinfo
5402 =head2 C<postponed_sub>
5404 Handles setting postponed breakpoints in subroutines once they're compiled.
5405 For breakpoints, we use C<DB::find_sub> to locate the source file and line
5406 range for the subroutine, then mark the file as having a breakpoint,
5407 temporarily switch the C<*dbline> glob over to the source file, and then
5408 search the given range of lines to find a breakable line. If we find one,
5409 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
5413 # The following takes its argument via $evalarg to preserve current @_
5417 # Get the subroutine name.
5418 my $subname = shift;
5420 # If this is a 'break +<n> if <condition>' ...
5421 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
5423 # If there's no offset, use '+0'.
5424 my $offset = $1 || 0;
5426 # find_sub's value is 'fullpath-filename:start-stop'. It's
5427 # possible that the filename might have colons in it too.
5428 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
5431 # We got the start line. Add the offset '+<n>' from
5432 # $postponed{subname}.
5435 # Switch to the file this sub is in, temporarily.
5436 local *dbline = $main::{ '_<' . $file };
5438 # No warnings, please.
5439 local $^W = 0; # != 0 is magical below
5441 # This file's got a breakpoint in it.
5442 $had_breakpoints{$file} |= 1;
5444 # Last line in file.
5447 # Search forward until we hit a breakable line or get to
5448 # the end of the file.
5449 ++$i until $dbline[$i] != 0 or $i >= $max;
5451 # Copy the breakpoint in and delete it from %postponed.
5452 $dbline{$i} = delete $postponed{$subname};
5455 # find_sub didn't find the sub.
5458 print $OUT "Subroutine $subname not found.\n";
5461 } ## end if ($postponed{$subname...
5462 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
5464 #print $OUT "In postponed_sub for `$subname'.\n";
5465 } ## end sub postponed_sub
5469 Called after each required file is compiled, but before it is executed;
5470 also called if the name of a just-compiled subroutine is a key of
5471 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
5472 etc.) into the just-compiled code.
5474 If this is a C<require>'d file, the incoming parameter is the glob
5475 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
5477 If it's a subroutine, the incoming parameter is the subroutine name.
5483 # If there's a break, process it.
5484 if ($ImmediateStop) {
5486 # Right, we've stopped. Turn it off.
5489 # Enter the command loop when DB::DB gets called.
5493 # If this is a subroutine, let postponed_sub() deal with it.
5494 return &postponed_sub unless ref \$_[0] eq 'GLOB';
5496 # Not a subroutine. Deal with the file.
5497 local *dbline = shift;
5498 my $filename = $dbline;
5499 $filename =~ s/^_<//;
5501 $signal = 1, print $OUT "'$filename' loaded...\n"
5502 if $break_on_load{$filename};
5503 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
5505 # Do we have any breakpoints to put in this file?
5506 return unless $postponed_file{$filename};
5508 # Yes. Mark this file as having breakpoints.
5509 $had_breakpoints{$filename} |= 1;
5511 # "Cannot be done: unsufficient magic" - we can't just put the
5512 # breakpoints saved in %postponed_file into %dbline by assigning
5513 # the whole hash; we have to do it one item at a time for the
5514 # breakpoints to be set properly.
5515 #%dbline = %{$postponed_file{$filename}};
5517 # Set the breakpoints, one at a time.
5520 for $key ( keys %{ $postponed_file{$filename} } ) {
5522 # Stash the saved breakpoint into the current file's magic line array.
5523 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
5526 # This file's been compiled; discard the stored breakpoints.
5527 delete $postponed_file{$filename};
5529 } ## end sub postponed
5533 C<dumpit> is the debugger's wrapper around dumpvar.pl.
5535 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
5536 a reference to a variable (the thing to be dumped) as its input.
5538 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
5539 the currently-selected filehandle, thank you very much). The current
5540 values of the package globals C<$single> and C<$trace> are backed up in
5541 lexicals, and they are turned off (this keeps the debugger from trying
5542 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
5543 preserve its current value and it is set to zero to prevent entry/exit
5544 messages from printing, and C<$doret> is localized as well and set to -2 to
5545 prevent return values from being shown.
5547 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
5548 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
5549 installed version in C<@INC>, yours will be used instead. Possible security
5552 It then checks to see if the subroutine C<main::dumpValue> is now defined
5553 (it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
5554 localizes the globals necessary for things to be sane when C<main::dumpValue()>
5555 is called, and picks up the variable to be dumped from the parameter list.
5557 It checks the package global C<%options> to see if there's a C<dumpDepth>
5558 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
5559 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
5560 structure: -1 means dump everything.
5562 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
5565 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
5566 and we then return to the caller.
5572 # Save the current output filehandle and switch to the one
5573 # passed in as the first parameter.
5574 local ($savout) = select(shift);
5576 # Save current settings of $single and $trace, and then turn them off.
5577 my $osingle = $single;
5578 my $otrace = $trace;
5579 $single = $trace = 0;
5581 # XXX Okay, what do $frame and $doret do, again?
5585 # Load dumpvar.pl unless we've already got the sub we need from it.
5586 unless ( defined &main::dumpValue ) {
5590 # If the load succeeded (or we already had dumpvalue()), go ahead
5592 if ( defined &main::dumpValue ) {
5597 my $maxdepth = shift || $option{dumpDepth};
5598 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
5599 &main::dumpValue( $v, $maxdepth );
5600 } ## end if (defined &main::dumpValue)
5602 # Oops, couldn't load dumpvar.pl.
5605 print $OUT "dumpvar.pl not available.\n";
5608 # Reset $single and $trace to their old values.
5612 # Restore the old filehandle.
5616 =head2 C<print_trace>
5618 C<print_trace>'s job is to print a stack trace. It does this via the
5619 C<dump_trace> routine, which actually does all the ferreting-out of the
5620 stack trace data. C<print_trace> takes care of formatting it nicely and
5621 printing it to the proper filehandle.
5629 The filehandle to print to.
5633 How many frames to skip before starting trace.
5637 How many frames to print.
5641 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
5645 The original comment below seems to be noting that the traceback may not be
5646 correct if this routine is called in a tied method.
5650 # Tied method do not create a context, so may get wrong message:
5656 # If this is going to a slave editor, but we're not the primary
5657 # debugger, reset it first.
5659 if $fh eq $LINEINFO # slave editor
5660 and $LINEINFO eq $OUT # normal output
5661 and $term_pid != $$; # not the primary
5663 # Collect the actual trace information to be formatted.
5664 # This is an array of hashes of subroutine call info.
5665 my @sub = dump_trace( $_[0] + 1, $_[1] );
5667 # Grab the "short report" flag from @_.
5668 my $short = $_[2]; # Print short report, next one for sub name
5670 # Run through the traceback info, format it, and print it.
5672 for ( $i = 0 ; $i <= $#sub ; $i++ ) {
5674 # Drop out if the user has lost interest and hit control-C.
5677 # Set the separator so arrys print nice.
5680 # Grab and stringify the arguments if they are there.
5682 defined $sub[$i]{args}
5683 ? "(@{ $sub[$i]{args} })"
5686 # Shorten them up if $maxtrace says they're too long.
5687 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
5688 if length $args > $maxtrace;
5690 # Get the file name.
5691 my $file = $sub[$i]{file};
5693 # Put in a filename header if short is off.
5694 $file = $file eq '-e' ? $file : "file `$file'" unless $short;
5696 # Get the actual sub's name, and shorten to $maxtrace's requirement.
5698 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
5700 # Short report uses trimmed file and sub names.
5702 my $sub = @_ >= 4 ? $_[3] : $s;
5703 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
5704 } ## end if ($short)
5706 # Non-short report includes full names.
5708 print $fh "$sub[$i]{context} = $s$args"
5709 . " called from $file"
5710 . " line $sub[$i]{line}\n";
5712 } ## end for ($i = 0 ; $i <= $#sub...
5713 } ## end sub print_trace
5715 =head2 dump_trace(skip[,count])
5717 Actually collect the traceback information available via C<caller()>. It does
5718 some filtering and cleanup of the data, but mostly it just collects it to
5719 make C<print_trace()>'s job easier.
5721 C<skip> defines the number of stack frames to be skipped, working backwards
5722 from the most current. C<count> determines the total number of frames to
5723 be returned; all of them (well, the first 10^9) are returned if C<count>
5726 This routine returns a list of hashes, from most-recent to least-recent
5727 stack frame. Each has the following keys and values:
5731 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
5733 =item * C<sub> - subroutine name, or C<eval> information
5735 =item * C<args> - undef, or a reference to an array of arguments
5737 =item * C<file> - the file in which this item was defined (if any)
5739 =item * C<line> - the line on which it was defined
5747 # How many levels to skip.
5750 # How many levels to show. (1e9 is a cheap way of saying "all of them";
5751 # it's unlikely that we'll have more than a billion stack frames. If you
5752 # do, you've got an awfully big machine...)
5753 my $count = shift || 1e9;
5755 # We increment skip because caller(1) is the first level *back* from
5756 # the current one. Add $skip to the count of frames so we have a
5757 # simple stop criterion, counting from $skip to $count+$skip.
5761 # These variables are used to capture output from caller();
5762 my ( $p, $file, $line, $sub, $h, $context );
5764 my ( $e, $r, @a, @sub, $args );
5766 # XXX Okay... why'd we do that?
5767 my $nothard = not $frame & 8;
5770 # Do not want to trace this.
5771 my $otrace = $trace;
5774 # Start out at the skip count.
5775 # If we haven't reached the number of frames requested, and caller() is
5776 # still returning something, stay in the loop. (If we pass the requested
5777 # number of stack frames, or we run out - caller() returns nothing - we
5779 # Up the stack frame index to go back one more level each time.
5783 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
5788 # Go through the arguments and save them for later.
5792 if ( not defined $arg ) { # undefined parameter
5796 elsif ( $nothard and tied $arg ) { # tied parameter
5799 elsif ( $nothard and $type = ref $arg ) { # reference
5800 push @a, "ref($type)";
5802 else { # can be stringified
5804 "$arg"; # Safe to stringify now - should not call f().
5806 # Backslash any single-quotes or backslashes.
5809 # Single-quote it unless it's a number or a colon-separated
5812 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
5814 # Turn high-bit characters into meta-whatever.
5815 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
5817 # Turn control characters into ^-whatever.
5818 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
5821 } ## end else [ if (not defined $arg)
5822 } ## end for $arg (@args)
5824 # If context is true, this is array (@)context.
5825 # If context is false, this is scalar ($) context.
5826 # If neither, context isn't defined. (This is apparently a 'can't
5828 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
5830 # if the sub has args ($h true), make an anonymous array of the
5832 $args = $h ? [@a] : undef;
5834 # remove trailing newline-whitespace-semicolon-end of line sequence
5835 # from the eval text, if any.
5836 $e =~ s/\n\s*\;\s*\Z// if $e;
5838 # Escape backslashed single-quotes again if necessary.
5839 $e =~ s/([\\\'])/\\$1/g if $e;
5841 # if the require flag is true, the eval text is from a require.
5843 $sub = "require '$e'";
5846 # if it's false, the eval text is really from an eval.
5847 elsif ( defined $r ) {
5851 # If the sub is '(eval)', this is a block eval, meaning we don't
5852 # know what the eval'ed text actually was.
5853 elsif ( $sub eq '(eval)' ) {
5854 $sub = "eval {...}";
5857 # Stick the collected information into @sub as an anonymous hash.
5861 context => $context,
5869 # Stop processing frames if the user hit control-C.
5871 } ## end for ($i = $skip ; $i < ...
5873 # Restore the trace value again.
5876 } ## end sub dump_trace
5880 C<action()> takes input provided as the argument to an add-action command,
5881 either pre- or post-, and makes sure it's a complete command. It doesn't do
5882 any fancy parsing; it just keeps reading input until it gets a string
5883 without a trailing backslash.
5890 while ( $action =~ s/\\$// ) {
5892 # We have a backslash on the end. Read more.
5894 } ## end while ($action =~ s/\\$//)
5896 # Return the assembled action.
5902 This routine mostly just packages up a regular expression to be used
5903 to check that the thing it's being matched against has properly-matched
5906 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
5907 speeds things up by only creating the qr//'ed expression once; if it's
5908 already defined, we don't try to define it again. A speed hack.
5914 # I hate using globals!
5915 $balanced_brace_re ||= qr{
5918 (?> [^{}] + ) # Non-parens without backtracking
5920 (??{ $balanced_brace_re }) # Group with matching parens
5924 return $_[0] !~ m/$balanced_brace_re/;
5925 } ## end sub unbalanced
5929 C<gets()> is a primitive (very primitive) routine to read continuations.
5930 It was devised for reading continuations for actions.
5931 it just reads more input with C<readline()> and returns it.
5936 &readline("cont: ");
5939 =head2 C<DB::system()> - handle calls to<system()> without messing up the debugger
5941 The C<system()> function assumes that it can just go ahead and use STDIN and
5942 STDOUT, but under the debugger, we want it to use the debugger's input and
5945 C<DB::system()> socks away the program's STDIN and STDOUT, and then substitutes
5946 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
5947 and then puts everything back again.
5953 # We save, change, then restore STDIN and STDOUT to avoid fork() since
5954 # some non-Unix systems can do system() but have problems with fork().
5955 open( SAVEIN, "<&STDIN" ) || &warn("Can't save STDIN");
5956 open( SAVEOUT, ">&STDOUT" ) || &warn("Can't save STDOUT");
5957 open( STDIN, "<&IN" ) || &warn("Can't redirect STDIN");
5958 open( STDOUT, ">&OUT" ) || &warn("Can't redirect STDOUT");
5960 # XXX: using csh or tcsh destroys sigint retvals!
5962 open( STDIN, "<&SAVEIN" ) || &warn("Can't restore STDIN");
5963 open( STDOUT, ">&SAVEOUT" ) || &warn("Can't restore STDOUT");
5967 # most of the $? crud was coping with broken cshisms
5969 &warn( "(Command exited ", ( $? >> 8 ), ")\n" );
5973 "(Command died of SIG#",
5975 ( ( $? & 128 ) ? " -- core dumped" : "" ),
5984 =head1 TTY MANAGEMENT
5986 The subs here do some of the terminal management for multiple debuggers.
5990 Top-level function called when we want to set up a new terminal for use
5993 If the C<noTTY> debugger option was set, we'll either use the terminal
5994 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
5995 to find one. If we're a forked debugger, we call C<resetterm> to try to
5996 get a whole new terminal if we can.
5998 In either case, we set up the terminal next. If the C<ReadLine> option was
5999 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6000 the appropriate attributes. We then
6006 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6009 eval { require Term::ReadLine } or die $@;
6011 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6014 my ( $i, $o ) = split $tty, /,/;
6015 $o = $i unless defined $o;
6016 open( IN, "<$i" ) or die "Cannot open TTY `$i' for read: $!";
6017 open( OUT, ">$o" ) or die "Cannot open TTY `$o' for write: $!";
6020 my $sel = select($OUT);
6025 # We don't have a TTY - try to find one via Term::Rendezvous.
6027 eval "require Term::Rendezvous;" or die;
6029 # See if we have anything to pass to Term::Rendezvous.
6030 # Use $HOME/.perldbtty$$ if not.
6031 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6033 # Rendezvous and get the filehandles.
6034 my $term_rv = new Term::Rendezvous $rv;
6036 $OUT = $term_rv->OUT;
6037 } ## end else [ if ($tty)
6038 } ## end if ($notty)
6040 # We're a daughter debugger. Try to fork off another TTY.
6041 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6045 # If we shouldn't use Term::ReadLine, don't.
6047 $term = new Term::ReadLine::Stub 'perldb', $IN, $OUT;
6050 # We're using Term::ReadLine. Get all the attributes for this terminal.
6052 $term = new Term::ReadLine 'perldb', $IN, $OUT;
6054 $rl_attribs = $term->Attribs;
6055 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6056 if defined $rl_attribs->{basic_word_break_characters}
6057 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6058 $rl_attribs->{special_prefixes} = '$@&%';
6059 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6060 $rl_attribs->{completion_function} = \&db_complete;
6061 } ## end else [ if (!$rl)
6063 # Set up the LINEINFO filehandle.
6064 $LINEINFO = $OUT unless defined $LINEINFO;
6065 $lineinfo = $console unless defined $lineinfo;
6069 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6070 $term->SetHistory(@hist);
6073 # XXX Ornaments are turned on unconditionally, which is not
6074 # always a good thing.
6075 ornaments($ornaments) if defined $ornaments;
6077 } ## end sub setterm
6079 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6081 When the process being debugged forks, or the process invokes a command
6082 via C<system()> which starts a new debugger, we need to be able to get a new
6083 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6084 fight over the terminal, and you can never quite be sure who's going to get the
6085 input you're typing.
6087 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6088 is tasked with doing all the necessary operating system mojo to get a new
6089 TTY (and probably another window) and to direct the new debugger to read and
6092 The debugger provides C<get_fork_TTY> functions which work for X Windows,
6093 OS/2, and Mac OS X. Other systems are not supported. You are encouraged
6094 to write C<get_fork_TTY> functions which work for I<your> platform
6095 and contribute them.
6097 =head3 C<xterm_get_fork_TTY>
6099 This function provides the C<get_fork_TTY> function for X windows. If a
6100 program running under the debugger forks, a new <xterm> window is opened and
6101 the subsidiary debugger is directed there.
6103 The C<open()> call is of particular note here. We have the new C<xterm>
6104 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6105 command (which prints the device name of the TTY we'll want to use for input
6106 and output to STDOUT, then C<sleep> for a very long time, routing this output
6107 to file number 3. This way we can simply read from the <XT> filehandle (which
6108 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6110 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6115 sub xterm_get_fork_TTY {
6116 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6118 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6121 # Get the output from 'tty' and clean it up a little.
6125 $pidprompt = ''; # Shown anyway in titlebar
6127 # There's our new TTY.
6129 } ## end sub xterm_get_fork_TTY
6131 =head3 C<os2_get_fork_TTY>
6133 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6137 # This example function resets $IN, $OUT itself
6138 sub os2_get_fork_TTY {
6139 local $^F = 40; # XXXX Fixme!
6141 my ( $in1, $out1, $in2, $out2 );
6143 # Having -d in PERL5OPT would lead to a disaster...
6144 local $ENV{PERL5OPT} = $ENV{PERL5OPT} if $ENV{PERL5OPT};
6145 $ENV{PERL5OPT} =~ s/(?:^|(?<=\s))-d\b// if $ENV{PERL5OPT};
6146 $ENV{PERL5OPT} =~ s/(?:^|(?<=\s))-d\B/-/ if $ENV{PERL5OPT};
6147 print $OUT "Making kid PERL5OPT->`$ENV{PERL5OPT}'.\n" if $ENV{PERL5OPT};
6148 local $ENV{PERL5LIB} = $ENV{PERL5LIB} ? $ENV{PERL5LIB} : $ENV{PERLLIB};
6149 $ENV{PERL5LIB} = '' unless defined $ENV{PERL5LIB};
6150 $ENV{PERL5LIB} = join ';', @ini_INC, split /;/, $ENV{PERL5LIB};
6151 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6156 and pipe $in2, $out2
6158 # system P_SESSION will fail if there is another process
6159 # in the same session with a "dependent" asynchronous child session.
6161 $rl, fileno $in1, fileno $out2, "Daughter Perl debugger $pids $name"
6164 ( $kpid = CORE::system 4, $^X, '-we',
6165 <<'ES', @args ) >= 0 # P_SESSION
6166 END {sleep 5 unless $loaded}
6167 BEGIN {open STDIN, '</dev/con' or warn "reopen stdin: $!"}
6170 my ($rl, $in) = (shift, shift); # Read from $in and pass through
6172 system P_NOWAIT, $^X, '-we', <<EOS or die "Cannot start a grandkid";
6173 open IN, '<&=$in' or die "open <&=$in: \$!";
6174 \$| = 1; print while sysread IN, \$_, 1<<16;
6178 open OUT, ">&=$out" or die "Cannot open &=$out for writing: $!";
6180 require Term::ReadKey if $rl;
6181 Term::ReadKey::ReadMode(4) if $rl; # Nodelay on kbd. Pipe is automatically nodelay...
6182 print while sysread STDIN, $_, 1<<($rl ? 16 : 0);
6184 or warn "system P_SESSION: $!, $^E" and 0
6190 $pidprompt = ''; # Shown anyway in titlebar
6191 reset_IN_OUT( $in2, $out1 );
6193 return ''; # Indicate that reset_IN_OUT is called
6194 } ## end if (pipe $in1, $out1 and...
6196 } ## end sub os2_get_fork_TTY
6198 =head3 C<macosx_get_fork_TTY>
6200 The Mac OS X version uses AppleScript to tell Terminal.app to create
6205 # Notes about Terminal.app's AppleScript support,
6206 # (aka things that might break in future OS versions).
6208 # The "do script" command doesn't return a reference to the new window
6209 # it creates, but since it appears frontmost and windows are enumerated
6210 # front to back, we can use "first window" === "window 1".
6212 # There's no direct accessor for the tty device name, so we fiddle
6213 # with the window title options until it says what we want.
6215 # Tested and found to be functional in Mac OS X 10.3.9 and 10.4.8.
6217 sub macosx_get_fork_TTY
6221 return unless open($pipe,'-|','/usr/bin/osascript','-e',<<'__SCRIPT__');
6222 tell application "Terminal"
6223 do script "clear;exec sleep 100000"
6225 set title displays shell path to false
6226 set title displays window size to false
6227 set title displays file name to false
6228 set title displays device name to true
6229 set title displays custom title to true
6230 set custom title to ""
6231 copy name to thetitle
6232 set custom title to "forked perl debugger"
6238 $tty=readline($pipe);
6240 return unless defined($tty) && $tty =~ m(^/dev/);
6245 =head2 C<create_IN_OUT($flags)>
6247 Create a new pair of filehandles, pointing to a new TTY. If impossible,
6248 try to diagnose why.
6254 =item * 1 - Don't know how to create a new TTY.
6256 =item * 2 - Debugger has forked, but we can't get a new TTY.
6258 =item * 4 - standard debugger startup is happening.
6264 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
6266 # If we know how to get a new TTY, do it! $in will have
6267 # the TTY name if get_fork_TTY works.
6268 my $in = &get_fork_TTY if defined &get_fork_TTY;
6270 # It used to be that
6271 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
6273 if ( not defined $in ) {
6276 # We don't know how.
6277 print_help(<<EOP) if $why == 1;
6278 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
6282 print_help(<<EOP) if $why == 2;
6283 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
6284 This may be an asynchronous session, so the parent debugger may be active.
6287 # Note that both debuggers are fighting over the same input.
6288 print_help(<<EOP) if $why != 4;
6289 Since two debuggers fight for the same TTY, input is severely entangled.
6293 I know how to switch the output to a different window in xterms, OS/2
6294 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
6295 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
6296 B<DB::get_fork_TTY()> returning this.
6298 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
6299 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
6302 } ## end if (not defined $in)
6303 elsif ( $in ne '' ) {
6307 $console = ''; # Indicate no need to open-from-the-console
6310 } ## end sub create_IN_OUT
6314 Handles rejiggering the prompt when we've forked off a new debugger.
6316 If the new debugger happened because of a C<system()> that invoked a
6317 program under the debugger, the arrow between the old pid and the new
6318 in the prompt has I<two> dashes instead of one.
6320 We take the current list of pids and add this one to the end. If there
6321 isn't any list yet, we make one up out of the initial pid associated with
6322 the terminal and our new pid, sticking an arrow (either one-dashed or
6323 two dashed) in between them.
6325 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
6326 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
6331 sub resetterm { # We forked, so we need a different TTY
6333 # Needs to be passed to create_IN_OUT() as well.
6336 # resetterm(2): got in here because of a system() starting a debugger.
6337 # resetterm(1): just forked.
6338 my $systemed = $in > 1 ? '-' : '';
6340 # If there's already a list of pids, add this to the end.
6342 $pids =~ s/\]/$systemed->$$]/;
6345 # No pid list. Time to make one.
6347 $pids = "[$term_pid->$$]";
6350 # The prompt we're going to be using for this debugger.
6353 # We now 0wnz this terminal.
6356 # Just return if we're not supposed to try to create a new TTY.
6357 return unless $CreateTTY & $in;
6359 # Try to create a new IN/OUT pair.
6361 } ## end sub resetterm
6365 First, we handle stuff in the typeahead buffer. If there is any, we shift off
6366 the next line, print a message saying we got it, add it to the terminal
6367 history (if possible), and return it.
6369 If there's nothing in the typeahead buffer, check the command filehandle stack.
6370 If there are any filehandles there, read from the last one, and return the line
6371 if we got one. If not, we pop the filehandle off and close it, and try the
6372 next one up the stack.
6374 If we've emptied the filehandle stack, we check to see if we've got a socket
6375 open, and we read that and return it if we do. If we don't, we just call the
6376 core C<readline()> and return its value.
6382 # Localize to prevent it from being smashed in the program being debugged.
6385 # Pull a line out of the typeahead if there's stuff there.
6388 # How many lines left.
6389 my $left = @typeahead;
6391 # Get the next line.
6392 my $got = shift @typeahead;
6394 # Print a message saying we got input from the typeahead.
6396 print $OUT "auto(-$left)", shift, $got, "\n";
6398 # Add it to the terminal history (if possible).
6399 $term->AddHistory($got)
6401 and defined $term->Features->{addHistory};
6403 } ## end if (@typeahead)
6405 # We really need to read some input. Turn off entry/exit trace and
6406 # return value printing.
6410 # If there are stacked filehandles to read from ...
6413 # Read from the last one in the stack.
6414 my $line = CORE::readline( $cmdfhs[-1] );
6416 # If we got a line ...
6418 ? ( print $OUT ">> $line" and return $line ) # Echo and return
6419 : close pop @cmdfhs; # Pop and close
6420 } ## end while (@cmdfhs)
6422 # Nothing on the filehandle stack. Socket?
6423 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
6425 # Send anyting we have to send.
6426 $OUT->write( join( '', @_ ) );
6428 # Receive anything there is to receive.
6433 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
6434 # XXX Don't know. You tell me.
6435 } while length $buf and ($stuff .= $buf) !~ /\n/;
6439 } ## end if (ref $OUT and UNIVERSAL::isa...
6441 # No socket. Just read from the terminal.
6443 $term->readline(@_);
6445 } ## end sub readline
6447 =head1 OPTIONS SUPPORT ROUTINES
6449 These routines handle listing and setting option values.
6451 =head2 C<dump_option> - list the current value of an option setting
6453 This routine uses C<option_val> to look up the value for an option.
6454 It cleans up escaped single-quotes and then displays the option and
6460 my ( $opt, $val ) = @_;
6461 $val = option_val( $opt, 'N/A' );
6462 $val =~ s/([\\\'])/\\$1/g;
6463 printf $OUT "%20s = '%s'\n", $opt, $val;
6464 } ## end sub dump_option
6466 sub options2remember {
6467 foreach my $k (@RememberOnROptions) {
6468 $option{$k} = option_val( $k, 'N/A' );
6473 =head2 C<option_val> - find the current value of an option
6475 This can't just be a simple hash lookup because of the indirect way that
6476 the option values are stored. Some are retrieved by calling a subroutine,
6477 some are just variables.
6479 You must supply a default value to be used in case the option isn't set.
6484 my ( $opt, $default ) = @_;
6487 # Does this option exist, and is it a variable?
6488 # If so, retrieve the value via the value in %optionVars.
6489 if ( defined $optionVars{$opt}
6490 and defined ${ $optionVars{$opt} } )
6492 $val = ${ $optionVars{$opt} };
6495 # Does this option exist, and it's a subroutine?
6496 # If so, call the subroutine via the ref in %optionAction
6497 # and capture the value.
6498 elsif ( defined $optionAction{$opt}
6499 and defined &{ $optionAction{$opt} } )
6501 $val = &{ $optionAction{$opt} }();
6504 # If there's an action or variable for the supplied option,
6505 # but no value was set, use the default.
6506 elsif (defined $optionAction{$opt} and not defined $option{$opt}
6507 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
6512 # Otherwise, do the simple hash lookup.
6514 $val = $option{$opt};
6517 # If the value isn't defined, use the default.
6518 # Then return whatever the value is.
6519 $val = $default unless defined $val;
6521 } ## end sub option_val
6523 =head2 C<parse_options>
6525 Handles the parsing and execution of option setting/displaying commands.
6527 An option entered by itself is assumed to be I<set me to 1> (the default value)
6528 if the option is a boolean one. If not, the user is prompted to enter a valid
6529 value or to query the current value (via C<option? >).
6531 If C<option=value> is entered, we try to extract a quoted string from the
6532 value (if it is quoted). If it's not, we just use the whole value as-is.
6534 We load any modules required to service this option, and then we set it: if
6535 it just gets stuck in a variable, we do that; if there's a subroutine to
6536 handle setting the option, we call that.
6538 Finally, if we're running in interactive mode, we display the effect of the
6539 user's command back to the terminal, skipping this if we're setting things
6540 during initialization.
6548 # These options need a value. Don't allow them to be clobbered by accident.
6549 my %opt_needs_val = map { ( $_ => 1 ) } qw{
6550 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
6551 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
6557 # Clean off excess leading whitespace.
6560 # Options are always all word characters, followed by a non-word
6562 s/^(\w+)(\W?)// or print( $OUT "Invalid option `$_'\n" ), last;
6563 my ( $opt, $sep ) = ( $1, $2 );
6565 # Make sure that such an option exists.
6566 my $matches = grep( /^\Q$opt/ && ( $option = $_ ), @options )
6567 || grep( /^\Q$opt/i && ( $option = $_ ), @options );
6569 print( $OUT "Unknown option `$opt'\n" ), next unless $matches;
6570 print( $OUT "Ambiguous option `$opt'\n" ), next if $matches > 1;
6573 # '?' as separator means query, but must have whitespace after it.
6574 if ( "?" eq $sep ) {
6575 print( $OUT "Option query `$opt?' followed by non-space `$_'\n" ),
6579 #&dump_option($opt);
6580 } ## end if ("?" eq $sep)
6582 # Separator is whitespace (or just a carriage return).
6583 # They're going for a default, which we assume is 1.
6584 elsif ( $sep !~ /\S/ ) {
6586 $val = "1"; # this is an evil default; make 'em set it!
6589 # Separator is =. Trying to set a value.
6590 elsif ( $sep eq "=" ) {
6592 # If quoted, extract a quoted string.
6593 if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
6595 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
6598 # Not quoted. Use the whole thing. Warn about 'option='.
6602 print OUT qq(Option better cleared using $opt=""\n)
6604 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
6606 } ## end elsif ($sep eq "=")
6608 # "Quoted" with [], <>, or {}.
6609 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
6611 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
6612 s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
6613 or print( $OUT "Unclosed option value `$opt$sep$_'\n" ), last;
6614 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
6615 } ## end else [ if ("?" eq $sep)
6617 # Exclude non-booleans from getting set to 1 by default.
6618 if ( $opt_needs_val{$option} && $val_defaulted ) {
6619 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
6621 "Option `$opt' is non-boolean. Use `$cmd $option=VAL' to set, `$cmd $option?' to query\n";
6623 } ## end if ($opt_needs_val{$option...
6625 # Save the option value.
6626 $option{$option} = $val if defined $val;
6628 # Load any module that this option requires.
6632 require '$optionRequire{$option}';
6634 } || die # XXX: shouldn't happen
6635 if defined $optionRequire{$option}
6639 # Stick it in the proper variable if it goes in a variable.
6640 ${ $optionVars{$option} } = $val
6641 if defined $optionVars{$option}
6644 # Call the appropriate sub if it gets set via sub.
6645 &{ $optionAction{$option} }($val)
6646 if defined $optionAction{$option}
6647 && defined &{ $optionAction{$option} }
6650 # Not initialization - echo the value we set it to.
6651 dump_option($option) unless $OUT eq \*STDERR;
6652 } ## end while (length)
6653 } ## end sub parse_options
6655 =head1 RESTART SUPPORT
6657 These routines are used to store (and restore) lists of items in environment
6658 variables during a restart.
6662 Set_list packages up items to be stored in a set of environment variables
6663 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
6664 the values). Values outside the standard ASCII charset are stored by encoding
6665 then as hexadecimal values.
6670 my ( $stem, @list ) = @_;
6673 # VAR_n: how many we have. Scalar assignment gets the number of items.
6674 $ENV{"${stem}_n"} = @list;
6676 # Grab each item in the list, escape the backslashes, encode the non-ASCII
6677 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
6678 for $i ( 0 .. $#list ) {
6680 $val =~ s/\\/\\\\/g;
6681 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
6682 $ENV{"${stem}_$i"} = $val;
6683 } ## end for $i (0 .. $#list)
6684 } ## end sub set_list
6688 Reverse the set_list operation: grab VAR_n to see how many we should be getting
6689 back, and then pull VAR_0, VAR_1. etc. back out.
6696 my $n = delete $ENV{"${stem}_n"};
6698 for $i ( 0 .. $n - 1 ) {
6699 $val = delete $ENV{"${stem}_$i"};
6700 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
6704 } ## end sub get_list
6706 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
6710 The C<catch()> subroutine is the essence of fast and low-impact. We simply
6711 set an already-existing global scalar variable to a constant value. This
6712 avoids allocating any memory possibly in the middle of something that will
6713 get all confused if we do, particularly under I<unsafe signals>.
6719 return; # Put nothing on the stack - malloc/free land!
6724 C<warn> emits a warning, by joining together its arguments and printing
6725 them, with couple of fillips.
6727 If the composited message I<doesn't> end with a newline, we automatically
6728 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
6729 to be set to the filehandle to be used to output warnings; it makes no
6730 assumptions about what filehandles are available.
6735 my ($msg) = join( "", @_ );
6736 $msg .= ": $!\n" unless $msg =~ /\n$/;
6741 =head1 INITIALIZATION TTY SUPPORT
6743 =head2 C<reset_IN_OUT>
6745 This routine handles restoring the debugger's input and output filehandles
6746 after we've tried and failed to move them elsewhere. In addition, it assigns
6747 the debugger's output filehandle to $LINEINFO if it was already open there.
6752 my $switch_li = $LINEINFO eq $OUT;
6754 # If there's a term and it's able to get a new tty, try to get one.
6755 if ( $term and $term->Features->{newTTY} ) {
6756 ( $IN, $OUT ) = ( shift, shift );
6757 $term->newTTY( $IN, $OUT );
6760 # This term can't get a new tty now. Better luck later.
6762 &warn("Too late to set IN/OUT filehandles, enabled on next `R'!\n");
6765 # Set the filehndles up as they were.
6767 ( $IN, $OUT ) = ( shift, shift );
6770 # Unbuffer the output filehandle.
6771 my $o = select $OUT;
6775 # Point LINEINFO to the same output filehandle if it was there before.
6776 $LINEINFO = $OUT if $switch_li;
6777 } ## end sub reset_IN_OUT
6779 =head1 OPTION SUPPORT ROUTINES
6781 The following routines are used to process some of the more complicated
6786 Sets the input and output filehandles to the specified files or pipes.
6787 If the terminal supports switching, we go ahead and do it. If not, and
6788 there's already a terminal in place, we save the information to take effect
6791 If there's no terminal yet (for instance, during debugger initialization),
6792 we go ahead and set C<$console> and C<$tty> to the file indicated.
6798 # With VMS we can get here with $term undefined, so we do not
6799 # switch to this terminal. There may be a better place to make
6800 # sure that $term is defined on VMS
6801 if ( @_ and ($^O eq 'VMS') and !defined($term) ) {
6802 eval { require Term::ReadLine } or die $@;
6804 $term = new Term::ReadLine::Stub 'perldb', $IN, $OUT;
6807 $term = new Term::ReadLine 'perldb', $IN, $OUT;
6810 if ( @_ and $term and $term->Features->{newTTY} ) {
6812 # This terminal supports switching to a new TTY.
6813 # Can be a list of two files, or on string containing both names,
6815 # XXX Should this perhaps be an assignment from @_?
6816 my ( $in, $out ) = shift;
6819 # Split list apart if supplied.
6820 ( $in, $out ) = split /,/, $in, 2;
6824 # Use the same file for both input and output.
6828 # Open file onto the debugger's filehandles, if you can.
6829 open IN, $in or die "cannot open `$in' for read: $!";
6830 open OUT, ">$out" or die "cannot open `$out' for write: $!";
6832 # Swap to the new filehandles.
6833 reset_IN_OUT( \*IN, \*OUT );
6835 # Save the setting for later.
6837 } ## end if (@_ and $term and $term...
6839 # Terminal doesn't support new TTY, or doesn't support readline.
6840 # Can't do it now, try restarting.
6841 &warn("Too late to set TTY, enabled on next `R'!\n") if $term and @_;
6843 # Useful if done through PERLDB_OPTS:
6844 $console = $tty = shift if @_;
6846 # Return whatever the TTY is.
6852 Sets the C<$notty> global, controlling whether or not the debugger tries to
6853 get a terminal to read from. If called after a terminal is already in place,
6854 we save the value to use it if we're restarted.
6860 &warn("Too late to set noTTY, enabled on next `R'!\n") if @_;
6862 $notty = shift if @_;
6868 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
6869 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
6870 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
6871 the value in case a restart is done so we can change it then.
6877 &warn("Too late to set ReadLine, enabled on next `R'!\n") if @_;
6881 } ## end sub ReadLine
6883 =head2 C<RemotePort>
6885 Sets the port that the debugger will try to connect to when starting up.
6886 If the terminal's already been set up, we can't do it, but we remember the
6887 setting in case the user does a restart.
6893 &warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
6895 $remoteport = shift if @_;
6897 } ## end sub RemotePort
6901 Checks with the terminal to see if C<Tk> is running, and returns true or
6902 false. Returns false if the current terminal doesn't support C<readline>.
6907 if ( ${ $term->Features }{tkRunning} ) {
6908 return $term->tkRunning(@_);
6912 print $OUT "tkRunning not supported by current ReadLine package.\n";
6915 } ## end sub tkRunning
6919 Sets nonstop mode. If a terminal's already been set up, it's too late; the
6920 debugger remembers the setting in case you restart, though.
6926 &warn("Too late to set up NonStop mode, enabled on next `R'!\n")
6929 $runnonstop = shift if @_;
6931 } ## end sub NonStop
6935 &warn("Some flag changes could not take effect until next 'R'!\n")
6938 $^P = parse_DollarCaretP_flags(shift) if @_;
6939 expand_DollarCaretP_flags($^P);
6942 sub OnlyAssertions {
6944 &warn("Too late to set up OnlyAssertions mode, enabled on next 'R'!\n")
6948 unless ( defined $ini_assertion ) {
6950 &warn("Current Perl interpreter doesn't support assertions");
6955 unless ($ini_assertion) {
6956 print "Assertions will be active on next 'R'!\n";
6959 $^P &= ~$DollarCaretP_flags{PERLDBf_SUB};
6960 $^P |= $DollarCaretP_flags{PERLDBf_ASSERTION};
6963 $^P |= $DollarCaretP_flags{PERLDBf_SUB};
6966 !( $^P & $DollarCaretP_flags{PERLDBf_SUB} ) || 0;
6971 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
6979 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
6986 Sets the shell escape command, and generates a printable copy to be used
6993 # If we got an argument, meta-quote it, and add '\b' if it
6994 # ends in a word character.
6996 $sh = quotemeta shift;
6997 $sh .= "\\b" if $sh =~ /\w$/;
7000 # Generate the printable version for the help:
7001 $psh = $sh; # copy it
7002 $psh =~ s/\\b$//; # Take off trailing \b if any
7003 $psh =~ s/\\(.)/$1/g; # De-escape
7004 $psh; # return the printable version
7005 } ## end sub shellBang
7009 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7010 was passed as the argument. (This means you can't override the terminal's
7016 if ( defined $term ) {
7018 # We don't want to show warning backtraces, but we do want die() ones.
7019 local ( $warnLevel, $dieLevel ) = ( 0, 1 );
7021 # No ornaments if the terminal doesn't support them.
7022 return '' unless $term->Features->{ornaments};
7023 eval { $term->ornaments(@_) } || '';
7026 # Use what was passed in if we can't determine it ourselves.
7030 } ## end sub ornaments
7032 =head2 C<recallCommand>
7034 Sets the recall command, and builds a printable version which will appear in
7041 # If there is input, metaquote it. Add '\b' if it ends with a word
7044 $rc = quotemeta shift;
7045 $rc .= "\\b" if $rc =~ /\w$/;
7048 # Build it into a printable version.
7049 $prc = $rc; # Copy it
7050 $prc =~ s/\\b$//; # Remove trailing \b
7051 $prc =~ s/\\(.)/$1/g; # Remove escapes
7052 $prc; # Return the printable version
7053 } ## end sub recallCommand
7055 =head2 C<LineInfo> - where the line number information goes
7057 Called with no arguments, returns the file or pipe that line info should go to.
7059 Called with an argument (a file or a pipe), it opens that onto the
7060 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7061 file or pipe again to the caller.
7066 return $lineinfo unless @_;
7069 # If this is a valid "thing to be opened for output", tack a
7070 # '>' onto the front.
7071 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7073 # If this is a pipe, the stream points to a slave editor.
7074 $slave_editor = ( $stream =~ /^\|/ );
7076 # Open it up and unbuffer it.
7077 open( LINEINFO, "$stream" ) || &warn("Cannot open `$stream' for write");
7078 $LINEINFO = \*LINEINFO;
7079 my $save = select($LINEINFO);
7083 # Hand the file or pipe back again.
7085 } ## end sub LineInfo
7087 =head1 COMMAND SUPPORT ROUTINES
7089 These subroutines provide functionality for various commands.
7091 =head2 C<list_modules>
7093 For the C<M> command: list modules loaded and their versions.
7094 Essentially just runs through the keys in %INC, picks each package's
7095 C<$VERSION> variable, gets the file name, and formats the information
7100 sub list_modules { # versions
7104 # keys are the "as-loaded" name, values are the fully-qualified path
7105 # to the file itself.
7107 $file = $_; # get the module name
7108 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
7109 s,/,::,g; # change '/' to '::'
7110 s/^perl5db$/DB/; # Special case: debugger
7111 # moves to package DB
7112 s/^Term::ReadLine::readline$/readline/; # simplify readline
7114 # If the package has a $VERSION package global (as all good packages
7115 # should!) decode it and save as partial message.
7116 if ( defined ${ $_ . '::VERSION' } ) {
7117 $version{$file} = "${ $_ . '::VERSION' } from ";
7120 # Finish up the message with the file the package came from.
7121 $version{$file} .= $INC{$file};
7122 } ## end for (keys %INC)
7124 # Hey, dumpit() formats a hash nicely, so why not use it?
7125 dumpit( $OUT, \%version );
7126 } ## end sub list_modules
7130 Sets up the monster string used to format and print the help.
7132 =head3 HELP MESSAGE FORMAT
7134 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
7135 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
7136 easy to parse and portable, but which still allows the help to be a little
7137 nicer than just plain text.
7139 Essentially, you define the command name (usually marked up with C<< B<> >>
7140 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
7141 newline. The descriptive text can also be marked up in the same way. If you
7142 need to continue the descriptive text to another line, start that line with
7143 just tabs and then enter the marked-up text.
7145 If you are modifying the help text, I<be careful>. The help-string parser is
7146 not very sophisticated, and if you don't follow these rules it will mangle the
7147 help beyond hope until you fix the string.
7153 # XXX: make sure there are tabs between the command and explanation,
7154 # or print_help will screw up your formatting if you have
7155 # eeevil ornaments enabled. This is an insane mess.
7158 Help is currently only available for the new 5.8 command set.
7159 No help is available for the old command set.
7160 We assume you know what you're doing if you switch to it.
7163 B<s> [I<expr>] Single step [in I<expr>].
7164 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7165 <B<CR>> Repeat last B<n> or B<s> command.
7166 B<r> Return from current subroutine.
7167 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7168 at the specified position.
7169 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7170 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7171 B<l> I<line> List single I<line>.
7172 B<l> I<subname> List first window of lines from subroutine.
7173 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7174 B<l> List next window of lines.
7175 B<-> List previous window of lines.
7176 B<v> [I<line>] View window around I<line>.
7177 B<.> Return to the executed line.
7178 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7179 I<filename> may be either the full name of the file, or a regular
7180 expression matching the full file name:
7181 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7182 Evals (with saved bodies) are considered to be filenames:
7183 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7184 (in the order of execution).
7185 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7186 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7187 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
7188 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7189 B<t> Toggle trace mode.
7190 B<t> I<expr> Trace through execution of I<expr>.
7191 B<b> Sets breakpoint on current line)
7192 B<b> [I<line>] [I<condition>]
7193 Set breakpoint; I<line> defaults to the current execution line;
7194 I<condition> breaks if it evaluates to true, defaults to '1'.
7195 B<b> I<subname> [I<condition>]
7196 Set breakpoint at first line of subroutine.
7197 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7198 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7199 B<b> B<postpone> I<subname> [I<condition>]
7200 Set breakpoint at first line of subroutine after
7202 B<b> B<compile> I<subname>
7203 Stop after the subroutine is compiled.
7204 B<B> [I<line>] Delete the breakpoint for I<line>.
7205 B<B> I<*> Delete all breakpoints.
7206 B<a> [I<line>] I<command>
7207 Set an action to be done before the I<line> is executed;
7208 I<line> defaults to the current execution line.
7209 Sequence is: check for breakpoint/watchpoint, print line
7210 if necessary, do action, prompt user if necessary,
7213 B<A> [I<line>] Delete the action for I<line>.
7214 B<A> I<*> Delete all actions.
7215 B<w> I<expr> Add a global watch-expression.
7217 B<W> I<expr> Delete a global watch-expression.
7218 B<W> I<*> Delete all watch-expressions.
7219 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7220 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7221 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7222 B<x> I<expr> Evals expression in list context, dumps the result.
7223 B<m> I<expr> Evals expression in list context, prints methods callable
7224 on the first element of the result.
7225 B<m> I<class> Prints methods callable via the given class.
7226 B<M> Show versions of loaded modules.
7227 B<i> I<class> Prints nested parents of given class.
7228 B<e> Display current thread id.
7229 B<E> Display all thread ids the current one will be identified: <n>.
7230 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7231 B<P> Something to do with assertions...
7233 B<<> ? List Perl commands to run before each prompt.
7234 B<<> I<expr> Define Perl command to run before each prompt.
7235 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7236 B<< *> Delete the list of perl commands to run before each prompt.
7237 B<>> ? List Perl commands to run after each prompt.
7238 B<>> I<expr> Define Perl command to run after each prompt.
7239 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7240 B<>>B< *> Delete the list of Perl commands to run after each prompt.
7241 B<{> I<db_command> Define debugger command to run before each prompt.
7242 B<{> ? List debugger commands to run before each prompt.
7243 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7244 B<{ *> Delete the list of debugger commands to run before each prompt.
7245 B<$prc> I<number> Redo a previous command (default previous command).
7246 B<$prc> I<-number> Redo number'th-to-last command.
7247 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7248 See 'B<O> I<recallCommand>' too.
7249 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7254 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7256 See 'B<O> I<shellBang>' too.
7257 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7258 B<save> I<file> Save current debugger session (actual history) to I<file>.
7259 B<rerun> Rerun session to current position.
7260 B<rerun> I<n> Rerun session to numbered command.
7261 B<rerun> I<-n> Rerun session to number'th-to-last command.
7262 B<H> I<-number> Display last number commands (default all).
7263 B<H> I<*> Delete complete history.
7264 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7265 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7266 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7267 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7268 I<command> Execute as a perl statement in current package.
7269 B<R> Pure-man-restart of debugger, some of debugger state
7270 and command-line options may be lost.
7271 Currently the following settings are preserved:
7272 history, breakpoints and actions, debugger B<O>ptions
7273 and the following command-line options: I<-w>, I<-I>, I<-e>.
7275 B<o> [I<opt>] ... Set boolean option to true
7276 B<o> [I<opt>B<?>] Query options
7277 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7278 Set options. Use quotes in spaces in value.
7279 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7280 I<pager> program for output of \"|cmd\";
7281 I<tkRunning> run Tk while prompting (with ReadLine);
7282 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7283 I<inhibit_exit> Allows stepping off the end of the script.
7284 I<ImmediateStop> Debugger should stop as early as possible.
7285 I<RemotePort> Remote hostname:port for remote debugging
7286 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7287 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7288 I<compactDump>, I<veryCompact> change style of array and hash dump;
7289 I<globPrint> whether to print contents of globs;
7290 I<DumpDBFiles> dump arrays holding debugged files;
7291 I<DumpPackages> dump symbol tables of packages;
7292 I<DumpReused> dump contents of \"reused\" addresses;
7293 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7294 I<bareStringify> Do not print the overload-stringified value;
7295 Other options include:
7296 I<PrintRet> affects printing of return value after B<r> command,
7297 I<frame> affects printing messages on subroutine entry/exit.
7298 I<AutoTrace> affects printing messages on possible breaking points.
7299 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7300 I<ornaments> affects screen appearance of the command line.
7301 I<CreateTTY> bits control attempts to create a new TTY on events:
7302 1: on fork() 2: debugger is started inside debugger
7304 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7305 You can put additional initialization options I<TTY>, I<noTTY>,
7306 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7307 `B<R>' after you set them).
7309 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7310 B<h> Summary of debugger commands.
7311 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7312 B<h h> Long help for debugger commands
7313 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7314 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7315 Set B<\$DB::doccmd> to change viewer.
7317 Type `|h h' for a paged display if this was too hard to read.
7319 "; # Fix balance of vi % matching: }}}}
7321 # note: tabs in the following section are not-so-helpful
7322 $summary = <<"END_SUM";
7323 I<List/search source lines:> I<Control script execution:>
7324 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7325 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7326 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
7327 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7328 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7329 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
7330 I<Debugger controls:> B<L> List break/watch/actions
7331 B<o> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7332 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7333 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
7334 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7335 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
7336 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
7337 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
7338 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7339 B<q> or B<^D> Quit B<R> Attempt a restart
7340 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7341 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7342 B<p> I<expr> Print expression (uses script's current package).
7343 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7344 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7345 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
7346 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7347 B<e> Display thread id B<E> Display all thread ids.
7348 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7351 # ')}}; # Fix balance of vi % matching
7353 # and this is really numb...
7356 B<s> [I<expr>] Single step [in I<expr>].
7357 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7358 B<CR>> Repeat last B<n> or B<s> command.
7359 B<r> Return from current subroutine.
7360 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7361 at the specified position.
7362 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7363 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7364 B<l> I<line> List single I<line>.
7365 B<l> I<subname> List first window of lines from subroutine.
7366 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7367 B<l> List next window of lines.
7368 B<-> List previous window of lines.
7369 B<w> [I<line>] List window around I<line>.
7370 B<.> Return to the executed line.
7371 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7372 I<filename> may be either the full name of the file, or a regular
7373 expression matching the full file name:
7374 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7375 Evals (with saved bodies) are considered to be filenames:
7376 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7377 (in the order of execution).
7378 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7379 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7380 B<L> List all breakpoints and actions.
7381 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7382 B<t> Toggle trace mode.
7383 B<t> I<expr> Trace through execution of I<expr>.
7384 B<b> [I<line>] [I<condition>]
7385 Set breakpoint; I<line> defaults to the current execution line;
7386 I<condition> breaks if it evaluates to true, defaults to '1'.
7387 B<b> I<subname> [I<condition>]
7388 Set breakpoint at first line of subroutine.
7389 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7390 B<b> B<load> I<filename> Set breakpoint on `require'ing the given file.
7391 B<b> B<postpone> I<subname> [I<condition>]
7392 Set breakpoint at first line of subroutine after
7394 B<b> B<compile> I<subname>
7395 Stop after the subroutine is compiled.
7396 B<d> [I<line>] Delete the breakpoint for I<line>.
7397 B<D> Delete all breakpoints.
7398 B<a> [I<line>] I<command>
7399 Set an action to be done before the I<line> is executed;
7400 I<line> defaults to the current execution line.
7401 Sequence is: check for breakpoint/watchpoint, print line
7402 if necessary, do action, prompt user if necessary,
7404 B<a> [I<line>] Delete the action for I<line>.
7405 B<A> Delete all actions.
7406 B<W> I<expr> Add a global watch-expression.
7407 B<W> Delete all watch-expressions.
7408 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7409 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7410 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7411 B<x> I<expr> Evals expression in list context, dumps the result.
7412 B<m> I<expr> Evals expression in list context, prints methods callable
7413 on the first element of the result.
7414 B<m> I<class> Prints methods callable via the given class.
7416 B<<> ? List Perl commands to run before each prompt.
7417 B<<> I<expr> Define Perl command to run before each prompt.
7418 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7419 B<>> ? List Perl commands to run after each prompt.
7420 B<>> I<expr> Define Perl command to run after each prompt.
7421 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7422 B<{> I<db_command> Define debugger command to run before each prompt.
7423 B<{> ? List debugger commands to run before each prompt.
7424 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7425 B<$prc> I<number> Redo a previous command (default previous command).
7426 B<$prc> I<-number> Redo number'th-to-last command.
7427 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7428 See 'B<O> I<recallCommand>' too.
7429 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7434 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7436 See 'B<O> I<shellBang>' too.
7437 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7438 B<H> I<-number> Display last number commands (default all).
7439 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7440 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7441 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7442 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7443 I<command> Execute as a perl statement in current package.
7444 B<v> Show versions of loaded modules.
7445 B<R> Pure-man-restart of debugger, some of debugger state
7446 and command-line options may be lost.
7447 Currently the following settings are preserved:
7448 history, breakpoints and actions, debugger B<O>ptions
7449 and the following command-line options: I<-w>, I<-I>, I<-e>.
7451 B<O> [I<opt>] ... Set boolean option to true
7452 B<O> [I<opt>B<?>] Query options
7453 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7454 Set options. Use quotes in spaces in value.
7455 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7456 I<pager> program for output of \"|cmd\";
7457 I<tkRunning> run Tk while prompting (with ReadLine);
7458 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7459 I<inhibit_exit> Allows stepping off the end of the script.
7460 I<ImmediateStop> Debugger should stop as early as possible.
7461 I<RemotePort> Remote hostname:port for remote debugging
7462 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7463 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7464 I<compactDump>, I<veryCompact> change style of array and hash dump;
7465 I<globPrint> whether to print contents of globs;
7466 I<DumpDBFiles> dump arrays holding debugged files;
7467 I<DumpPackages> dump symbol tables of packages;
7468 I<DumpReused> dump contents of \"reused\" addresses;
7469 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7470 I<bareStringify> Do not print the overload-stringified value;
7471 Other options include:
7472 I<PrintRet> affects printing of return value after B<r> command,
7473 I<frame> affects printing messages on subroutine entry/exit.
7474 I<AutoTrace> affects printing messages on possible breaking points.
7475 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7476 I<ornaments> affects screen appearance of the command line.
7477 I<CreateTTY> bits control attempts to create a new TTY on events:
7478 1: on fork() 2: debugger is started inside debugger
7480 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7481 You can put additional initialization options I<TTY>, I<noTTY>,
7482 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7483 `B<R>' after you set them).
7485 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7486 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7487 B<h h> Summary of debugger commands.
7488 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7489 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7490 Set B<\$DB::doccmd> to change viewer.
7492 Type `|h' for a paged display if this was too hard to read.
7494 "; # Fix balance of vi % matching: }}}}
7496 # note: tabs in the following section are not-so-helpful
7497 $pre580_summary = <<"END_SUM";
7498 I<List/search source lines:> I<Control script execution:>
7499 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7500 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7501 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
7502 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7503 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7504 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
7505 I<Debugger controls:> B<L> List break/watch/actions
7506 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7507 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7508 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
7509 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7510 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
7511 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
7512 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7513 B<q> or B<^D> Quit B<R> Attempt a restart
7514 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7515 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7516 B<p> I<expr> Print expression (uses script's current package).
7517 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7518 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7519 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
7520 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7521 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7524 # ')}}; # Fix balance of vi % matching
7526 } ## end sub sethelp
7528 =head2 C<print_help()>
7530 Most of what C<print_help> does is just text formatting. It finds the
7531 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
7532 terminal control characters to simulate them (courtesy of
7533 C<Term::ReadLine::TermCap>).
7540 # Restore proper alignment destroyed by eeevil I<> and B<>
7541 # ornaments: A pox on both their houses!
7543 # A help command will have everything up to and including
7544 # the first tab sequence padded into a field 16 (or if indented 20)
7545 # wide. If it's wider than that, an extra space will be added.
7547 ^ # only matters at start of line
7548 ( \040{4} | \t )* # some subcommands are indented
7549 ( < ? # so <CR> works
7550 [BI] < [^\t\n] + ) # find an eeevil ornament
7551 ( \t+ ) # original separation, discarded
7552 ( .* ) # this will now start (no earlier) than
7555 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
7556 my $clean = $command;
7557 $clean =~ s/[BI]<([^>]*)>/$1/g;
7559 # replace with this whole string:
7560 ($leadwhite ? " " x 4 : "")
7562 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
7567 s{ # handle bold ornaments
7568 B < ( [^>] + | > ) >
7570 $Term::ReadLine::TermCap::rl_term_set[2]
7572 . $Term::ReadLine::TermCap::rl_term_set[3]
7575 s{ # handle italic ornaments
7576 I < ( [^>] + | > ) >
7578 $Term::ReadLine::TermCap::rl_term_set[0]
7580 . $Term::ReadLine::TermCap::rl_term_set[1]
7585 } ## end sub print_help
7589 This routine does a lot of gyrations to be sure that the pager is C<less>.
7590 It checks for C<less> masquerading as C<more> and records the result in
7591 C<$ENV{LESS}> so we don't have to go through doing the stats again.
7597 # We already know if this is set.
7598 return if defined $ENV{LESS} && $ENV{LESS} =~ /r/;
7600 # Pager is less for sure.
7601 my $is_less = $pager =~ /\bless\b/;
7602 if ( $pager =~ /\bmore\b/ ) {
7604 # Nope, set to more. See what's out there.
7605 my @st_more = stat('/usr/bin/more');
7606 my @st_less = stat('/usr/bin/less');
7608 # is it really less, pretending to be more?
7611 && $st_more[0] == $st_less[0]
7612 && $st_more[1] == $st_less[1];
7613 } ## end if ($pager =~ /\bmore\b/)
7615 # changes environment!
7616 # 'r' added so we don't do (slow) stats again.
7617 $ENV{LESS} .= 'r' if $is_less;
7618 } ## end sub fix_less
7620 =head1 DIE AND WARN MANAGEMENT
7624 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
7625 to debug a debugger problem.
7627 It does its best to report the error that occurred, and then forces the
7628 program, debugger, and everything to die.
7634 # No entry/exit messages.
7637 # No return value prints.
7640 # set the abort signal handling to the default (just terminate).
7641 $SIG{'ABRT'} = 'DEFAULT';
7643 # If we enter the signal handler recursively, kill myself with an
7644 # abort signal (so we just terminate).
7645 kill 'ABRT', $$ if $panic++;
7647 # If we can show detailed info, do so.
7648 if ( defined &Carp::longmess ) {
7650 # Don't recursively enter the warn handler, since we're carping.
7651 local $SIG{__WARN__} = '';
7653 # Skip two levels before reporting traceback: we're skipping
7654 # mydie and confess.
7655 local $Carp::CarpLevel = 2; # mydie + confess
7657 # Tell us all about it.
7658 &warn( Carp::longmess("Signal @_") );
7661 # No Carp. Tell us about the signal as best we can.
7664 print $DB::OUT "Got signal @_\n";
7669 } ## end sub diesignal
7673 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
7674 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
7680 # No entry/exit trace.
7683 # No return value printing.
7686 # Turn off warn and die handling to prevent recursive entries to this
7688 local $SIG{__WARN__} = '';
7689 local $SIG{__DIE__} = '';
7691 # Load Carp if we can. If $^S is false (current thing being compiled isn't
7692 # done yet), we may not be able to do a require.
7693 eval { require Carp }
7694 if defined $^S; # If error/warning during compilation,
7695 # require may be broken.
7697 # Use the core warn() unless Carp loaded OK.
7699 "\nCannot print stack trace, load with -MCarp option to see stack" ),
7701 unless defined &Carp::longmess;
7703 # Save the current values of $single and $trace, and then turn them off.
7704 my ( $mysingle, $mytrace ) = ( $single, $trace );
7708 # We can call Carp::longmess without its being "debugged" (which we
7709 # don't want - we just want to use it!). Capture this for later.
7710 my $mess = Carp::longmess(@_);
7712 # Restore $single and $trace to their original values.
7713 ( $single, $trace ) = ( $mysingle, $mytrace );
7715 # Use the debugger's own special way of printing warnings to print
7716 # the stack trace message.
7722 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
7723 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
7724 single stepping and tracing during the call to C<Carp::longmess> to avoid
7725 debugging it - we just want to use it.
7727 If C<dieLevel> is zero, we let the program being debugged handle the
7728 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
7729 the debugger takes over all exception handling, printing a backtrace and
7730 displaying the exception via its C<dbwarn()> routine.
7737 local $SIG{__DIE__} = '';
7738 local $SIG{__WARN__} = '';
7742 if ( $dieLevel > 2 ) {
7743 local $SIG{__WARN__} = \&dbwarn;
7744 &warn(@_); # Yell no matter what
7747 if ( $dieLevel < 2 ) {
7748 die @_ if $^S; # in eval propagate
7751 # The code used to check $^S to see if compiliation of the current thing
7752 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
7753 eval { require Carp };
7756 "\nCannot print stack trace, load with -MCarp option to see stack" )
7757 unless defined &Carp::longmess;
7759 # We do not want to debug this chunk (automatic disabling works
7760 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
7761 # get the stack trace from Carp::longmess (if possible), restore $signal
7762 # and $trace, and then die with the stack trace.
7763 my ( $mysingle, $mytrace ) = ( $single, $trace );
7769 package Carp; # Do not include us in the list
7770 eval { $mess = Carp::longmess(@_); };
7772 ( $single, $trace ) = ( $mysingle, $mytrace );
7776 =head2 C<warnlevel()>
7778 Set the C<$DB::warnLevel> variable that stores the value of the
7779 C<warnLevel> option. Calling C<warnLevel()> with a positive value
7780 results in the debugger taking over all warning handlers. Setting
7781 C<warnLevel> to zero leaves any warning handlers set up by the program
7782 being debugged in place.
7788 $prevwarn = $SIG{__WARN__} unless $warnLevel;
7791 $SIG{__WARN__} = \&DB::dbwarn;
7794 $SIG{__WARN__} = $prevwarn;
7798 } ## end sub warnLevel
7802 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
7803 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
7804 zero lets you use your own C<die()> handler.
7811 $prevdie = $SIG{__DIE__} unless $dieLevel;
7815 # Always set it to dbdie() for non-zero values.
7816 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
7818 # No longer exists, so don't try to use it.
7819 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
7821 # If we've finished initialization, mention that stack dumps
7822 # are enabled, If dieLevel is 1, we won't stack dump if we die
7824 print $OUT "Stack dump during die enabled",
7825 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
7828 # XXX This is probably obsolete, given that diehard() is gone.
7829 print $OUT "Dump printed too.\n" if $dieLevel > 2;
7830 } ## end if ($dieLevel)
7832 # Put the old one back if there was one.
7834 $SIG{__DIE__} = $prevdie;
7835 print $OUT "Default die handler restored.\n";
7839 } ## end sub dieLevel
7841 =head2 C<signalLevel>
7843 Number three in a series: set C<signalLevel> to zero to keep your own
7844 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
7845 takes over and handles them with C<DB::diesignal()>.
7851 $prevsegv = $SIG{SEGV} unless $signalLevel;
7852 $prevbus = $SIG{BUS} unless $signalLevel;
7853 $signalLevel = shift;
7855 $SIG{SEGV} = \&DB::diesignal;
7856 $SIG{BUS} = \&DB::diesignal;
7859 $SIG{SEGV} = $prevsegv;
7860 $SIG{BUS} = $prevbus;
7864 } ## end sub signalLevel
7866 =head1 SUBROUTINE DECODING SUPPORT
7868 These subroutines are used during the C<x> and C<X> commands to try to
7869 produce as much information as possible about a code reference. They use
7870 L<Devel::Peek> to try to find the glob in which this code reference lives
7871 (if it does) - this allows us to actually code references which correspond
7872 to named subroutines (including those aliased via glob assignment).
7874 =head2 C<CvGV_name()>
7876 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
7877 via that routine. If this fails, return the reference again (when the
7878 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
7884 my $name = CvGV_name_or_bust($in);
7885 defined $name ? $name : $in;
7888 =head2 C<CvGV_name_or_bust> I<coderef>
7890 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
7891 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
7892 find a glob for this ref.
7894 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
7898 sub CvGV_name_or_bust {
7900 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
7901 return unless ref $in;
7902 $in = \&$in; # Hard reference...
7903 eval { require Devel::Peek; 1 } or return;
7904 my $gv = Devel::Peek::CvGV($in) or return;
7905 *$gv{PACKAGE} . '::' . *$gv{NAME};
7906 } ## end sub CvGV_name_or_bust
7910 A utility routine used in various places; finds the file where a subroutine
7911 was defined, and returns that filename and a line-number range.
7913 Tries to use C<@sub> first; if it can't find it there, it tries building a
7914 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
7915 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
7916 this way, it brute-force searches C<%sub>, checking for identical references.
7923 return unless defined &$subr;
7924 my $name = CvGV_name_or_bust($subr);
7926 $data = $sub{$name} if defined $name;
7927 return $data if defined $data;
7930 $subr = \&$subr; # Hard reference
7933 $s = $_, last if $subr eq \&$_;
7937 } ## end sub find_sub
7941 A subroutine that uses the utility function C<methods_via> to find all the
7942 methods in the class corresponding to the current reference and in
7949 # Figure out the class - either this is the class or it's a reference
7950 # to something blessed into that class.
7952 $class = ref $class if ref $class;
7956 # Show the methods that this class has.
7957 methods_via( $class, '', 1 );
7959 # Show the methods that UNIVERSAL has.
7960 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
7961 } ## end sub methods
7963 =head2 C<methods_via($class, $prefix, $crawl_upward)>
7965 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
7966 all the parent class methods. C<$class> is the name of the next class to
7967 try; C<$prefix> is the message prefix, which gets built up as we go up the
7968 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
7969 higher in the C<@ISA> tree, 0 if we should stop.
7975 # If we've processed this class already, just quit.
7977 return if $seen{$class}++;
7979 # This is a package that is contributing the methods we're about to print.
7981 my $prepend = $prefix ? "via $prefix: " : '';
7986 # Keep if this is a defined subroutine in this class.
7987 grep { defined &{ ${"${class}::"}{$_} } }
7989 # Extract from all the symbols in this class.
7990 sort keys %{"${class}::"}
7994 # If we printed this already, skip it.
7995 next if $seen{$name}++;
7997 # Print the new method name.
8000 print $DB::OUT "$prepend$name\n";
8001 } ## end for $name (grep { defined...
8003 # If the $crawl_upward argument is false, just quit here.
8004 return unless shift;
8006 # $crawl_upward true: keep going up the tree.
8007 # Find all the classes this one is a subclass of.
8008 for $name ( @{"${class}::ISA"} ) {
8010 # Set up the new prefix.
8011 $prepend = $prefix ? $prefix . " -> $name" : $name;
8013 # Crawl up the tree and keep trying to crawl up.
8014 methods_via( $name, $prepend, 1 );
8016 } ## end sub methods_via
8018 =head2 C<setman> - figure out which command to use to show documentation
8020 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8025 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|MacOS|NetWare)\z/s
8026 ? "man" # O Happy Day!
8027 : "perldoc"; # Alas, poor unfortunates
8030 =head2 C<runman> - run the appropriate command to show documentation
8032 Accepts a man page name; runs the appropriate command to display it (set up
8033 during debugger initialization). Uses C<DB::system> to avoid mucking up the
8034 program's STDIN and STDOUT.
8041 &system("$doccmd $doccmd");
8045 # this way user can override, like with $doccmd="man -Mwhatever"
8046 # or even just "man " to disable the path check.
8047 unless ( $doccmd eq 'man' ) {
8048 &system("$doccmd $page");
8052 $page = 'perl' if lc($page) eq 'help';
8055 my $man1dir = $Config::Config{'man1dir'};
8056 my $man3dir = $Config::Config{'man3dir'};
8057 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
8059 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
8060 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
8061 chop $manpath if $manpath;
8063 # harmless if missing, I figure
8064 my $oldpath = $ENV{MANPATH};
8065 $ENV{MANPATH} = $manpath if $manpath;
8066 my $nopathopt = $^O =~ /dunno what goes here/;
8071 # I just *know* there are men without -M
8072 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8077 unless ( $page =~ /^perl\w/ ) {
8078 # do it this way because its easier to slurp in to keep up to date - clunky though.
8217 if (grep { $page eq $_ } @pods) {
8219 CORE::system( $doccmd,
8220 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8222 } ## end if (grep { $page eq $_...
8223 } ## end unless ($page =~ /^perl\w/)
8224 } ## end if (CORE::system($doccmd...
8225 if ( defined $oldpath ) {
8226 $ENV{MANPATH} = $manpath;
8229 delete $ENV{MANPATH};
8233 #use Carp; # This did break, left for debugging
8235 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
8237 Because of the way the debugger interface to the Perl core is designed, any
8238 debugger package globals that C<DB::sub()> requires have to be defined before
8239 any subroutines can be called. These are defined in the second C<BEGIN> block.
8241 This block sets things up so that (basically) the world is sane
8242 before the debugger starts executing. We set up various variables that the
8243 debugger has to have set up before the Perl core starts running:
8249 The debugger's own filehandles (copies of STD and STDOUT for now).
8253 Characters for shell escapes, the recall command, and the history command.
8257 The maximum recursion depth.
8261 The size of a C<w> command's window.
8265 The before-this-line context to be printed in a C<v> (view a window around this line) command.
8269 The fact that we're not in a sub at all right now.
8273 The default SIGINT handler for the debugger.
8277 The appropriate value of the flag in C<$^D> that says the debugger is running
8281 The current debugger recursion level
8285 The list of postponed items and the C<$single> stack (XXX define this)
8289 That we want no return values and no subroutine entry/exit trace.
8295 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
8297 BEGIN { # This does not compile, alas. (XXX eh?)
8298 $IN = \*STDIN; # For bugs before DB::OUT has been opened
8299 $OUT = \*STDERR; # For errors before DB::OUT has been opened
8301 # Define characters used by command parsing.
8302 $sh = '!'; # Shell escape (does not work)
8303 $rc = ','; # Recall command (does not work)
8304 @hist = ('?'); # Show history (does not work)
8305 @truehist = (); # Can be saved for replay (per session)
8307 # This defines the point at which you get the 'deep recursion'
8308 # warning. It MUST be defined or the debugger will not load.
8311 # Number of lines around the current one that are shown in the
8315 # How much before-the-current-line context the 'v' command should
8316 # use in calculating the start of the window it will display.
8319 # We're not in any sub yet, but we need this to be a defined value.
8322 # Set up the debugger's interrupt handler. It simply sets a flag
8323 # ($signal) that DB::DB() will check before each command is executed.
8324 $SIG{INT} = \&DB::catch;
8326 # The following lines supposedly, if uncommented, allow the debugger to
8327 # debug itself. Perhaps we can try that someday.
8328 # This may be enabled to debug debugger:
8329 #$warnLevel = 1 unless defined $warnLevel;
8330 #$dieLevel = 1 unless defined $dieLevel;
8331 #$signalLevel = 1 unless defined $signalLevel;
8333 # This is the flag that says "a debugger is running, please call
8334 # DB::DB and DB::sub". We will turn it on forcibly before we try to
8335 # execute anything in the user's context, because we always want to
8337 $db_stop = 0; # Compiler warning ...
8338 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
8340 # This variable records how many levels we're nested in debugging. Used
8341 # Used in the debugger prompt, and in determining whether it's all over or
8343 $level = 0; # Level of recursive debugging
8345 # "Triggers bug (?) in perl if we postpone this until runtime."
8346 # XXX No details on this yet, or whether we should fix the bug instead
8347 # of work around it. Stay tuned.
8348 @postponed = @stack = (0);
8350 # Used to track the current stack depth using the auto-stacked-variable
8352 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
8354 # Don't print return values on exiting a subroutine.
8357 # No extry/exit tracing.
8362 BEGIN { $^W = $ini_warn; } # Switch warnings back
8364 =head1 READLINE SUPPORT - COMPLETION FUNCTION
8368 C<readline> support - adds command completion to basic C<readline>.
8370 Returns a list of possible completions to C<readline> when invoked. C<readline>
8371 will print the longest common substring following the text already entered.
8373 If there is only a single possible completion, C<readline> will use it in full.
8375 This code uses C<map> and C<grep> heavily to create lists of possible
8376 completion. Think LISP in this section.
8382 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
8383 # $text is the text to be completed.
8384 # $line is the incoming line typed by the user.
8385 # $start is the start of the text to be completed in the incoming line.
8386 my ( $text, $line, $start ) = @_;
8388 # Save the initial text.
8389 # The search pattern is current package, ::, extract the next qualifier
8390 # Prefix and pack are set to undef.
8391 my ( $itext, $search, $prefix, $pack ) =
8392 ( $text, "^\Q${'package'}::\E([^:]+)\$" );
8394 =head3 C<b postpone|compile>
8400 Find all the subroutines that might match in this package
8404 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
8408 Include all the rest of the subs that are known
8412 C<grep> out the ones that match the text we have so far
8416 Return this as the list of possible completions
8422 return sort grep /^\Q$text/, ( keys %sub ),
8423 qw(postpone load compile), # subroutines
8424 ( map { /$search/ ? ($1) : () } keys %sub )
8425 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
8429 Get all the possible files from C<@INC> as it currently stands and
8430 select the ones that match the text so far.
8434 return sort grep /^\Q$text/, values %INC # files
8435 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
8437 =head3 C<V> (list variable) and C<m> (list modules)
8439 There are two entry points for these commands:
8441 =head4 Unqualified package names
8443 Get the top-level packages and grab everything that matches the text
8444 so far. For each match, recursively complete the partial packages to
8445 get all possible matching packages. Return this sorted list.
8449 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8450 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
8451 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
8453 =head4 Qualified package names
8455 Take a partially-qualified package and find all subpackages for it
8456 by getting all the subpackages for the package so far, matching all
8457 the subpackages against the text, and discarding all of them which
8458 start with 'main::'. Return this list.
8462 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8463 grep !/^main::/, grep /^\Q$text/,
8464 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () } keys %{ $prefix . '::' }
8465 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
8466 and $text =~ /^(.*[^:])::?(\w*)$/
8469 =head3 C<f> - switch files
8471 Here, we want to get a fully-qualified filename for the C<f> command.
8476 =item 1. The original source file itself
8478 =item 2. A file from C<@INC>
8480 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
8486 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
8487 # We might possibly want to switch to an eval (which has a "filename"
8488 # like '(eval 9)'), so we may need to clean up the completion text
8489 # before proceeding.
8490 $prefix = length($1) - length($text);
8495 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
8496 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
8497 out of C<%main::>, add the initial source file, and extract the ones that
8498 match the completion text so far.
8503 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
8505 } ## end if ($line =~ /^\|*f\s+(.*)/)
8507 =head3 Subroutine name completion
8509 We look through all of the defined subs (the keys of C<%sub>) and
8510 return both all the possible matches to the subroutine name plus
8511 all the matches qualified to the current package.
8515 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
8516 $text = substr $text, 1;
8518 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
8520 map { /$search/ ? ($1) : () }
8523 } ## end if ((substr $text, 0, ...
8525 =head3 Scalar, array, and hash completion: partially qualified package
8527 Much like the above, except we have to do a little more cleanup:
8531 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
8539 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
8543 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
8549 Figure out the prefix vs. what needs completing.
8553 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
8560 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
8564 my @out = map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
8571 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.
8575 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8576 return db_complete( $out[0], $line, $start );
8579 # Return the list of possibles.
8582 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
8588 =head3 Symbol completion: current package or package C<main>.
8592 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
8600 If it's C<main>, delete main to just get C<::> leading.
8604 $pack = ( $package eq 'main' ? '' : $package ) . '::';
8610 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
8614 $prefix = substr $text, 0, 1;
8615 $text = substr $text, 1;
8621 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
8625 my @out = map "$prefix$_", grep /^\Q$text/,
8626 ( grep /^_?[a-zA-Z]/, keys %$pack ),
8627 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
8631 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
8637 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8638 return db_complete( $out[0], $line, $start );
8641 # Return the list of possibles.
8643 } ## end if ($text =~ /^[\$@%]/)
8647 We use C<option_val()> to look up the current value of the option. If there's
8648 only a single value, we complete the command in such a way that it is a
8649 complete command for setting the option in question. If there are multiple
8650 possible values, we generate a command consisting of the option plus a trailing
8651 question mark, which, if executed, will list the current value of the option.
8655 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
8656 { # Options after space
8657 # We look for the text to be matched in the list of possible options,
8658 # and fetch the current value.
8659 my @out = grep /^\Q$text/, @options;
8660 my $val = option_val( $out[0], undef );
8662 # Set up a 'query option's value' command.
8664 if ( not defined $val or $val =~ /[\n\r]/ ) {
8666 # There's really nothing else we can do.
8669 # We have a value. Create a proper option-setting command.
8670 elsif ( $val =~ /\s/ ) {
8672 # XXX This may be an extraneous variable.
8675 # We'll want to quote the string (because of the embedded
8676 # whtespace), but we want to make sure we don't end up with
8677 # mismatched quote characters. We try several possibilities.
8678 foreach $l ( split //, qq/\"\'\#\|/ ) {
8680 # If we didn't find this quote character in the value,
8681 # quote it using this quote character.
8682 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
8684 } ## end elsif ($val =~ /\s/)
8686 # Don't need any quotes.
8691 # If there were multiple possible values, return '? ', which
8692 # makes the command into a query command. If there was just one,
8693 # have readline append that.
8694 $rl_attribs->{completer_terminator_character} =
8695 ( @out == 1 ? $out : '? ' );
8697 # Return list of possibilities.
8699 } ## end if ((substr $line, 0, ...
8701 =head3 Filename completion
8703 For entering filenames. We simply call C<readline>'s C<filename_list()>
8704 method with the completion text to get the possible completions.
8708 return $term->filename_list($text); # filenames
8710 } ## end sub db_complete
8712 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
8714 Functions that possibly ought to be somewhere else.
8724 print $OUT "Use `q' to quit or `R' to restart. `h q' for details.\n";
8729 If we have $ini_pids, save it in the environment; else remove it from the
8730 environment. Used by the C<R> (restart) command.
8735 if ( defined($ini_pids) ) {
8736 $ENV{PERLDB_PIDS} = $ini_pids;
8739 delete( $ENV{PERLDB_PIDS} );
8741 } ## end sub clean_ENV
8743 # PERLDBf_... flag names from perl.h
8744 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
8747 %DollarCaretP_flags = (
8748 PERLDBf_SUB => 0x01, # Debug sub enter/exit
8749 PERLDBf_LINE => 0x02, # Keep line #
8750 PERLDBf_NOOPT => 0x04, # Switch off optimizations
8751 PERLDBf_INTER => 0x08, # Preserve more data
8752 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
8753 PERLDBf_SINGLE => 0x20, # Start with single-step on
8754 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
8755 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
8756 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
8757 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
8758 PERLDBf_ASSERTION => 0x400, # Debug assertion subs enter/exit
8759 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO, _ASSERTION
8762 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
8765 sub parse_DollarCaretP_flags {
8770 foreach my $f ( split /\s*\|\s*/, $flags ) {
8772 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
8775 elsif ( $f =~ /^(\d+)$/ ) {
8778 elsif ( $f =~ /^DEFAULT$/i ) {
8779 $value = $DollarCaretP_flags{PERLDB_ALL};
8782 $f =~ /^(?:PERLDBf_)?(.*)$/i;
8783 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
8784 unless ( defined $value ) {
8786 "Unrecognized \$^P flag '$f'!\n",
8787 "Acceptable flags are: "
8788 . join( ', ', sort keys %DollarCaretP_flags ),
8789 ", and hexadecimal and decimal numbers.\n"
8799 sub expand_DollarCaretP_flags {
8800 my $DollarCaretP = shift;
8803 my $n = ( 1 << $_ );
8804 ( $DollarCaretP & $n )
8805 ? ( $DollarCaretP_flags_r{$n}
8806 || sprintf( '0x%x', $n ) )
8810 return @bits ? join( '|', @bits ) : 0;
8817 Rerun the current session to:
8819 rerun current position
8821 rerun 4 command number 4
8823 rerun -4 current command minus 4 (go back 4 steps)
8825 Whether this always makes sense, in the current context is unknowable, and is
8826 in part left as a useful exersize for the reader. This sub returns the
8827 appropriate arguments to rerun the current session.
8834 pop(@truehist); # strim
8835 unless (defined $truehist[$i]) {
8836 print "Unable to return to non-existent command: $i\n";
8838 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
8839 my @temp = @truehist; # store
8840 push(@DB::typeahead, @truehist); # saved
8841 @truehist = @hist = (); # flush
8842 @args = &restart(); # setup
8843 &get_list("PERLDB_HIST"); # clean
8844 &set_list("PERLDB_HIST", @temp); # reset
8851 Restarting the debugger is a complex operation that occurs in several phases.
8852 First, we try to reconstruct the command line that was used to invoke Perl
8858 # I may not be able to resurrect you, but here goes ...
8860 "Warning: some settings and command-line options may be lost!\n";
8861 my ( @script, @flags, $cl );
8863 # If warn was on before, turn it on again.
8864 push @flags, '-w' if $ini_warn;
8865 if ( $ini_assertion and @{^ASSERTING} ) {
8867 ( map { /\:\^\(\?\:(.*)\)\$\)/ ? "-A$1" : "-A$_" }
8871 # Rebuild the -I flags that were on the initial
8874 push @flags, '-I', $_;
8877 # Turn on taint if it was on before.
8878 push @flags, '-T' if ${^TAINT};
8880 # Arrange for setting the old INC:
8881 # Save the current @init_INC in the environment.
8882 set_list( "PERLDB_INC", @ini_INC );
8884 # If this was a perl one-liner, go to the "file"
8885 # corresponding to the one-liner read all the lines
8886 # out of it (except for the first one, which is going
8887 # to be added back on again when 'perl -d' runs: that's
8888 # the 'require perl5db.pl;' line), and add them back on
8889 # to the command line to be executed.
8891 for ( 1 .. $#{'::_<-e'} ) { # The first line is PERL5DB
8892 chomp( $cl = ${'::_<-e'}[$_] );
8893 push @script, '-e', $cl;
8895 } ## end if ($0 eq '-e')
8897 # Otherwise we just reuse the original name we had
8905 After the command line has been reconstructed, the next step is to save
8906 the debugger's status in environment variables. The C<DB::set_list> routine
8907 is used to save aggregate variables (both hashes and arrays); scalars are
8908 just popped into environment variables directly.
8912 # If the terminal supported history, grab it and
8913 # save that in the environment.
8914 set_list( "PERLDB_HIST",
8915 $term->Features->{getHistory}
8919 # Find all the files that were visited during this
8920 # session (i.e., the debugger had magic hashes
8921 # corresponding to them) and stick them in the environment.
8922 my @had_breakpoints = keys %had_breakpoints;
8923 set_list( "PERLDB_VISITED", @had_breakpoints );
8925 # Save the debugger options we chose.
8926 set_list( "PERLDB_OPT", %option );
8927 # set_list( "PERLDB_OPT", options2remember() );
8929 # Save the break-on-loads.
8930 set_list( "PERLDB_ON_LOAD", %break_on_load );
8934 The most complex part of this is the saving of all of the breakpoints. They
8935 can live in an awful lot of places, and we have to go through all of them,
8936 find the breakpoints, and then save them in the appropriate environment
8937 variable via C<DB::set_list>.
8941 # Go through all the breakpoints and make sure they're
8944 for ( 0 .. $#had_breakpoints ) {
8946 # We were in this file.
8947 my $file = $had_breakpoints[$_];
8949 # Grab that file's magic line hash.
8950 *dbline = $main::{ '_<' . $file };
8952 # Skip out if it doesn't exist, or if the breakpoint
8953 # is in a postponed file (we'll do postponed ones
8955 next unless %dbline or $postponed_file{$file};
8957 # In an eval. This is a little harder, so we'll
8958 # do more processing on that below.
8959 ( push @hard, $file ), next
8960 if $file =~ /^\(\w*eval/;
8962 # XXX I have no idea what this is doing. Yet.
8964 @add = %{ $postponed_file{$file} }
8965 if $postponed_file{$file};
8967 # Save the list of all the breakpoints for this file.
8968 set_list( "PERLDB_FILE_$_", %dbline, @add );
8969 } ## end for (0 .. $#had_breakpoints)
8971 # The breakpoint was inside an eval. This is a little
8972 # more difficult. XXX and I don't understand it.
8974 # Get over to the eval in question.
8975 *dbline = $main::{ '_<' . $_ };
8976 my ( $quoted, $sub, %subs, $line ) = quotemeta $_;
8977 for $sub ( keys %sub ) {
8978 next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/;
8979 $subs{$sub} = [ $1, $2 ];
8983 "No subroutines in $_, ignoring breakpoints.\n";
8986 LINES: for $line ( keys %dbline ) {
8988 # One breakpoint per sub only:
8989 my ( $offset, $sub, $found );
8990 SUBS: for $sub ( keys %subs ) {
8993 $line # Not after the subroutine
8995 not defined $offset # Not caught
9001 $offset = $line - $subs{$sub}->[0];
9002 $offset = "+$offset", last SUBS
9004 } ## end if ($subs{$sub}->[1] >=...
9005 } ## end for $sub (keys %subs)
9006 if ( defined $offset ) {
9007 $postponed{$found} =
9008 "break $offset if $dbline{$line}";
9012 "Breakpoint in $_:$line ignored: after all the subroutines.\n";
9014 } ## end for $line (keys %dbline)
9015 } ## end for (@hard)
9017 # Save the other things that don't need to be
9019 set_list( "PERLDB_POSTPONE", %postponed );
9020 set_list( "PERLDB_PRETYPE", @$pretype );
9021 set_list( "PERLDB_PRE", @$pre );
9022 set_list( "PERLDB_POST", @$post );
9023 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9025 # We are oficially restarting.
9026 $ENV{PERLDB_RESTART} = 1;
9028 # We are junking all child debuggers.
9029 delete $ENV{PERLDB_PIDS}; # Restore ini state
9031 # Set this back to the initial pid.
9032 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9036 After all the debugger status has been saved, we take the command we built up
9037 and then return it, so we can C<exec()> it. The debugger will spot the
9038 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9039 from the environment.
9043 # And run Perl again. Add the "-d" flag, all the
9044 # flags we built up, the script (whether a one-liner
9045 # or a file), add on the -emacs flag for a slave editor,
9046 # and then the old arguments.
9048 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9054 =head1 END PROCESSING - THE C<END> BLOCK
9056 Come here at the very end of processing. We want to go into a
9057 loop where we allow the user to enter commands and interact with the
9058 debugger, but we don't want anything else to execute.
9060 First we set the C<$finished> variable, so that some commands that
9061 shouldn't be run after the end of program quit working.
9063 We then figure out whether we're truly done (as in the user entered a C<q>
9064 command, or we finished execution while running nonstop). If we aren't,
9065 we set C<$single> to 1 (causing the debugger to get control again).
9067 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9068 message and returns control to the debugger. Repeat.
9070 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9071 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9072 break, run to completion.).
9077 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9078 $fall_off_end = 1 unless $inhibit_exit;
9080 # Do not stop in at_exit() and destructors on exit:
9081 $DB::single = !$fall_off_end && !$runnonstop;
9082 DB::fake::at_exit() unless $fall_off_end or $runnonstop;
9085 =head1 PRE-5.8 COMMANDS
9087 Some of the commands changed function quite a bit in the 5.8 command
9088 realignment, so much so that the old code had to be replaced completely.
9089 Because we wanted to retain the option of being able to go back to the
9090 former command set, we moved the old code off to this section.
9092 There's an awful lot of duplicated code here. We've duplicated the
9093 comments to keep things clear.
9097 Does nothing. Used to I<turn off> commands.
9101 sub cmd_pre580_null {
9106 =head2 Old C<a> command.
9108 This version added actions if you supplied them, and deleted them
9117 # Argument supplied. Add the action.
9118 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9120 # If the line isn't there, use the current line.
9124 # If there is an action ...
9127 # ... but the line isn't breakable, skip it.
9128 if ( $dbline[$i] == 0 ) {
9129 print $OUT "Line $i may not have an action.\n";
9133 # ... and the line is breakable:
9134 # Mark that there's an action in this file.
9135 $had_breakpoints{$filename} |= 2;
9137 # Delete any current action.
9138 $dbline{$i} =~ s/\0[^\0]*//;
9140 # Add the new action, continuing the line as needed.
9141 $dbline{$i} .= "\0" . action($j);
9143 } ## end if (length $j)
9145 # No action supplied.
9148 # Delete the action.
9149 $dbline{$i} =~ s/\0[^\0]*//;
9151 # Mark as having no break or action if nothing's left.
9152 delete $dbline{$i} if $dbline{$i} eq '';
9154 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
9155 } ## end sub cmd_pre580_a
9157 =head2 Old C<b> command
9169 if ( $cmd =~ /^load\b\s*(.*)/ ) {
9175 # b compile|postpone <some sub> [<condition>]
9176 # The interpreter actually traps this one for us; we just put the
9177 # necessary condition in the %postponed hash.
9178 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
9180 # Capture the condition if there is one. Make it true if none.
9181 my $cond = length $3 ? $3 : '1';
9183 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
9184 # if it was 'compile'.
9185 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
9187 # De-Perl4-ify the name - ' separators to ::.
9188 $subname =~ s/\'/::/g;
9190 # Qualify it into the current package unless it's already qualified.
9191 $subname = "${'package'}::" . $subname
9192 unless $subname =~ /::/;
9194 # Add main if it starts with ::.
9195 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
9197 # Save the break type for this sub.
9198 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
9199 } ## end elsif ($cmd =~ ...
9201 # b <sub name> [<condition>]
9202 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
9204 my $cond = length $2 ? $2 : '1';
9205 &cmd_b_sub( $subname, $cond );
9208 # b <line> [<condition>].
9209 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9210 my $i = $1 || $dbline;
9211 my $cond = length $2 ? $2 : '1';
9212 &cmd_b_line( $i, $cond );
9214 } ## end sub cmd_pre580_b
9216 =head2 Old C<D> command.
9218 Delete all breakpoints unconditionally.
9225 if ( $cmd =~ /^\s*$/ ) {
9226 print $OUT "Deleting all breakpoints...\n";
9228 # %had_breakpoints lists every file that had at least one
9231 for $file ( keys %had_breakpoints ) {
9233 # Switch to the desired file temporarily.
9234 local *dbline = $main::{ '_<' . $file };
9239 # For all lines in this file ...
9240 for ( $i = 1 ; $i <= $max ; $i++ ) {
9242 # If there's a breakpoint or action on this line ...
9243 if ( defined $dbline{$i} ) {
9245 # ... remove the breakpoint.
9246 $dbline{$i} =~ s/^[^\0]+//;
9247 if ( $dbline{$i} =~ s/^\0?$// ) {
9249 # Remove the entry altogether if no action is there.
9252 } ## end if (defined $dbline{$i...
9253 } ## end for ($i = 1 ; $i <= $max...
9255 # If, after we turn off the "there were breakpoints in this file"
9256 # bit, the entry in %had_breakpoints for this file is zero,
9257 # we should remove this file from the hash.
9258 if ( not $had_breakpoints{$file} &= ~1 ) {
9259 delete $had_breakpoints{$file};
9261 } ## end for $file (keys %had_breakpoints)
9263 # Kill off all the other breakpoints that are waiting for files that
9264 # haven't been loaded yet.
9266 undef %postponed_file;
9267 undef %break_on_load;
9268 } ## end if ($cmd =~ /^\s*$/)
9269 } ## end sub cmd_pre580_D
9271 =head2 Old C<h> command
9273 Print help. Defaults to printing the long-form help; the 5.8 version
9274 prints the summary by default.
9282 # Print the *right* help, long format.
9283 if ( $cmd =~ /^\s*$/ ) {
9284 print_help($pre580_help);
9287 # 'h h' - explicitly-requested summary.
9288 elsif ( $cmd =~ /^h\s*/ ) {
9289 print_help($pre580_summary);
9292 # Find and print a command's help.
9293 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
9294 my $asked = $1; # for proper errmsg
9295 my $qasked = quotemeta($asked); # for searching
9296 # XXX: finds CR but not <CR>
9300 (?:[IB]<) # Optional markup
9301 $qasked # The command name
9308 ( # The command help:
9310 (?:[IB]<) # Optional markup
9311 $qasked # The command name
9312 ([\s\S]*?) # Lines starting with tabs
9316 ) # Line not starting with space
9317 # (Next command's help)
9321 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
9325 print_help("B<$asked> is not a debugger command.\n");
9327 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
9328 } ## end sub cmd_pre580_h
9330 =head2 Old C<W> command
9332 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
9340 # Delete all watch expressions.
9341 if ( $cmd =~ /^$/ ) {
9343 # No watching is going on.
9346 # Kill all the watch expressions and values.
9347 @to_watch = @old_watch = ();
9350 # Add a watch expression.
9351 elsif ( $cmd =~ /^(.*)/s ) {
9353 # add it to the list to be watched.
9356 # Get the current value of the expression.
9357 # Doesn't handle expressions returning list values!
9360 $val = ( defined $val ) ? "'$val'" : 'undef';
9363 push @old_watch, $val;
9365 # We're watching stuff.
9368 } ## end elsif ($cmd =~ /^(.*)/s)
9369 } ## end sub cmd_pre580_W
9371 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
9373 The debugger used to have a bunch of nearly-identical code to handle
9374 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
9375 C<cmd_prepost> unify all this into one set of code to handle the
9376 appropriate actions.
9378 =head2 C<cmd_pre590_prepost>
9380 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
9381 do something destructive. In pre 5.8 debuggers, the default action was to
9382 delete all the actions.
9386 sub cmd_pre590_prepost {
9388 my $line = shift || '*';
9391 return &cmd_prepost( $cmd, $line, $dbline );
9392 } ## end sub cmd_pre590_prepost
9394 =head2 C<cmd_prepost>
9396 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
9397 Since the lists of actions are all held in arrays that are pointed to by
9398 references anyway, all we have to do is pick the right array reference and
9399 then use generic code to all, delete, or list actions.
9406 # No action supplied defaults to 'list'.
9407 my $line = shift || '?';
9409 # Figure out what to put in the prompt.
9412 # Make sure we have some array or another to address later.
9413 # This means that if ssome reason the tests fail, we won't be
9414 # trying to stash actions or delete them from the wrong place.
9417 # < - Perl code to run before prompt.
9418 if ( $cmd =~ /^\</o ) {
9419 $which = 'pre-perl';
9423 # > - Perl code to run after prompt.
9424 elsif ( $cmd =~ /^\>/o ) {
9425 $which = 'post-perl';
9429 # { - first check for properly-balanced braces.
9430 elsif ( $cmd =~ /^\{/o ) {
9431 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
9433 "$cmd is now a debugger command\nuse `;$cmd' if you mean Perl code\n";
9436 # Properly balanced. Pre-prompt debugger actions.
9438 $which = 'pre-debugger';
9441 } ## end elsif ( $cmd =~ /^\{/o )
9443 # Did we find something that makes sense?
9445 print $OUT "Confused by command: $cmd\n";
9452 if ( $line =~ /^\s*\?\s*$/o ) {
9455 # Nothing there. Complain.
9456 print $OUT "No $which actions.\n";
9460 # List the actions in the selected list.
9461 print $OUT "$which commands:\n";
9462 foreach my $action (@$aref) {
9463 print $OUT "\t$cmd -- $action\n";
9466 } ## end if ( $line =~ /^\s*\?\s*$/o)
9468 # Might be a delete.
9470 if ( length($cmd) == 1 ) {
9471 if ( $line =~ /^\s*\*\s*$/o ) {
9473 # It's a delete. Get rid of the old actions in the
9476 print $OUT "All $cmd actions cleared.\n";
9480 # Replace all the actions. (This is a <, >, or {).
9481 @$aref = action($line);
9483 } ## end if ( length($cmd) == 1)
9484 elsif ( length($cmd) == 2 ) {
9486 # Add the action to the line. (This is a <<, >>, or {{).
9487 push @$aref, action($line);
9491 # <<<, >>>>, {{{{{{ ... something not a command.
9493 "Confused by strange length of $which command($cmd)...\n";
9495 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
9497 } ## end sub cmd_prepost
9501 Contains the C<at_exit> routine that the debugger uses to issue the
9502 C<Debugged program terminated ...> message after the program completes. See
9503 the C<END> block documentation for more details.
9510 "Debugged program terminated. Use `q' to quit or `R' to restart.";
9513 package DB; # Do not trace this 1; below!
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