4 C<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<$@> inside C<eval>s which C<eval> other C<eval's>.
72 In any case, watch for this pattern. It occurs fairly often.
76 This is used to cleverly reverse the sense of a logical test depending on
77 the value of an auxiliary variable. For instance, the debugger's C<S>
78 (search for subroutines by pattern) allows you to negate the pattern
81 # Find all non-'foo' subs:
84 Boolean algebra states that the truth table for XOR looks like this:
90 (! not present and no match) --> false, don't print
94 (! not present and matches) --> true, print
98 (! present and no match) --> true, print
102 (! present and matches) --> false, don't print
106 As you can see, the first pair applies when C<!> isn't supplied, and
107 the second pair applies when it isn't. The XOR simply allows us to
108 compact a more complicated if-then-elseif-else into a more elegant
109 (but perhaps overly clever) single test. After all, it needed this
112 =head2 FLAGS, FLAGS, FLAGS
114 There is a certain C programming legacy in the debugger. Some variables,
115 such as C<$single>, C<$trace>, and C<$frame>, have "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
136 =item * First, doing an arithmetical or bitwise operation on a scalar is
137 just about the fastest thing you can do in Perl: C<use constant> actually
138 creates a subroutine call, and array hand hash lookups are much slower. Is
139 this over-optimization at the expense of readability? Possibly, but the
140 debugger accesses these variables a I<lot>. Any rewrite of the code will
141 probably have to benchmark alternate implementations and see which is the
142 best balance of readability and speed, and then document how it actually
145 =item * Second, it's very easy to serialize a scalar number. This is done in
146 the restart code; the debugger state variables are saved in C<%ENV> and then
147 restored when the debugger is restarted. Having them be just numbers makes
150 =item * Third, some of these variables are being shared with the Perl core
151 smack in the middle of the interpreter's execution loop. It's much faster for
152 a C program (like the interpreter) to check a bit in a scalar than to access
153 several different variables (or a Perl array).
157 =head2 What are those C<XXX> comments for?
159 Any comment containing C<XXX> means that the comment is either somewhat
160 speculative - it's not exactly clear what a given variable or chunk of
161 code is doing, or that it is incomplete - the basics may be clear, but the
162 subtleties are not completely documented.
164 Send in a patch if you can clear up, fill out, or clarify an C<XXX>.
166 =head1 DATA STRUCTURES MAINTAINED BY CORE
168 There are a number of special data structures provided to the debugger by
169 the Perl interpreter.
171 The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline> via glob
172 assignment) contains the text from C<$filename>, with each element
173 corresponding to a single line of C<$filename>.
175 The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
176 assignment) contains breakpoints and actions. The keys are line numbers;
177 you can set individual values, but not the whole hash. The Perl interpreter
178 uses this hash to determine where breakpoints have been set. Any true value is
179 considered to be a breakpoint; C<perl5db.pl> uses "$break_condition\0$action".
180 Values are magical in numeric context: 1 if the line is breakable, 0 if not.
182 The scalar ${'_<'.$filename} contains $filename XXX What?
184 =head1 DEBUGGER STARTUP
186 When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
187 non-interactive sessions, C<.perldb> for interactive ones) that can set a number
188 of options. In addition, this file may define a subroutine C<&afterinit>
189 that will be executed (in the debugger's context) after the debugger has
192 Next, it checks the C<PERLDB_OPTS> environment variable and treats its
193 contents as the argument of a debugger <C<o> command.
195 =head2 STARTUP-ONLY OPTIONS
197 The following options can only be specified at startup.
198 To set them in your rcfile, add a call to
199 C<&parse_options("optionName=new_value")>.
205 the TTY to use for debugging i/o.
209 if set, goes in NonStop mode. On interrupt, if TTY is not set,
210 uses the value of noTTY or "/tmp/perldbtty$$" to find TTY using
211 Term::Rendezvous. Current variant is to have the name of TTY in this
216 If false, a dummy ReadLine is used, so you can debug
217 ReadLine applications.
221 if true, no i/o is performed until interrupt.
225 file or pipe to print line number info to. If it is a
226 pipe, a short "emacs like" message is used.
230 host:port to connect to on remote host for remote debugging.
236 &parse_options("NonStop=1 LineInfo=db.out");
237 sub afterinit { $trace = 1; }
239 The script will run without human intervention, putting trace
240 information into C<db.out>. (If you interrupt it, you had better
241 reset C<LineInfo> to something "interactive"!)
243 =head1 INTERNALS DESCRIPTION
245 =head2 DEBUGGER INTERFACE VARIABLES
247 Perl supplies the values for C<%sub>. It effectively inserts
248 a C<&DB'DB();> in front of each place that can have a
249 breakpoint. At each subroutine call, it calls C<&DB::sub> with
250 C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
251 {require 'perl5db.pl'}> before the first line.
253 After each C<require>d file is compiled, but before it is executed, a
254 call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
255 is the expanded name of the C<require>d file (as found via C<%INC>).
257 =head3 IMPORTANT INTERNAL VARIABLES
261 Used to control when the debugger will attempt to acquire another TTY to be
266 =item * 1 - on C<fork()>
268 =item * 2 - debugger is started inside debugger
270 =item * 4 - on startup
276 The value -2 indicates that no return value should be printed.
277 Any other positive value causes C<DB::sub> to print return values.
281 The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
282 contents of C<@_> when C<DB::eval> is called.
286 Determines what messages (if any) will get printed when a subroutine (or eval)
287 is entered or exited.
291 =item * 0 - No enter/exit messages
293 =item * 1 - Print "entering" messages on subroutine entry
295 =item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
297 =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.
299 =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.
301 =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.
305 To get everything, use C<$frame=30> (or C<o f-30> as a debugger command).
306 The debugger internally juggles the value of C<$frame> during execution to
307 protect external modules that the debugger uses from getting traced.
311 Tracks current debugger nesting level. Used to figure out how many
312 C<E<lt>E<gt>> pairs to surround the line number with when the debugger
313 outputs a prompt. Also used to help determine if the program has finished
314 during command parsing.
316 =head4 C<$onetimeDump>
318 Controls what (if anything) C<DB::eval()> will print after evaluating an
323 =item * C<undef> - don't print anything
325 =item * C<dump> - use C<dumpvar.pl> to display the value returned
327 =item * C<methods> - print the methods callable on the first item returned
331 =head4 C<$onetimeDumpDepth>
333 Controls how far down C<dumpvar.pl> will go before printing '...' while
334 dumping a structure. Numeric. If C<undef>, print all levels.
338 Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
339 which is called before every statement, checks this and puts the user into
340 command mode if it finds C<$signal> set to a true value.
344 Controls behavior during single-stepping. Stacked in C<@stack> on entry to
345 each subroutine; popped again at the end of each subroutine.
349 =item * 0 - run continuously.
351 =item * 1 - single-step, go into subs. The 's' command.
353 =item * 2 - single-step, don't go into subs. The 'n' command.
355 =item * 4 - print current sub depth (turned on to force this when "too much
362 Controls the output of trace information.
366 =item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
368 =item * 2 - watch expressions are active
370 =item * 4 - user defined a C<watchfunction()> in C<afterinit()>
374 =head4 C<$slave_editor>
376 1 if C<LINEINFO> was directed to a pipe; 0 otherwise.
380 Stack of filehandles that C<DB::readline()> will read commands from.
381 Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
385 Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
386 supplied by the Perl interpreter to the debugger. Contains the source.
390 Previous values of watch expressions. First set when the expression is
391 entered; reset whenever the watch expression changes.
395 Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
396 so that the debugger can substitute safe values while it's running, and
397 restore them when it returns control.
401 Saves the current value of C<$single> on entry to a subroutine.
402 Manipulated by the C<c> command to turn off tracing in all subs above the
407 The 'watch' expressions: to be evaluated before each line is executed.
411 The typeahead buffer, used by C<DB::readline>.
415 Command aliases. Stored as character strings to be substituted for a command
418 =head4 C<%break_on_load>
420 Keys are file names, values are 1 (break when this file is loaded) or undef
421 (don't break when it is loaded).
425 Keys are line numbers, values are "condition\0action". If used in numeric
426 context, values are 0 if not breakable, 1 if breakable, no matter what is
427 in the actual hash entry.
429 =head4 C<%had_breakpoints>
431 Keys are file names; values are bitfields:
435 =item * 1 - file has a breakpoint in it.
437 =item * 2 - file has an action in it.
441 A zero or undefined value means this file has neither.
445 Stores the debugger options. These are character string values.
449 Saves breakpoints for code that hasn't been compiled yet.
450 Keys are subroutine names, values are:
454 =item * 'compile' - break when this sub is compiled
456 =item * 'break +0 if <condition>' - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
460 =head4 C<%postponed_file>
462 This hash keeps track of breakpoints that need to be set for files that have
463 not yet been compiled. Keys are filenames; values are references to hashes.
464 Each of these hashes is keyed by line number, and its values are breakpoint
465 definitions ("condition\0action").
467 =head1 DEBUGGER INITIALIZATION
469 The debugger's initialization actually jumps all over the place inside this
470 package. This is because there are several BEGIN blocks (which of course
471 execute immediately) spread through the code. Why is that?
473 The debugger needs to be able to change some things and set some things up
474 before the debugger code is compiled; most notably, the C<$deep> variable that
475 C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
476 debugger has to turn off warnings while the debugger code is compiled, but then
477 restore them to their original setting before the program being debugged begins
480 The first C<BEGIN> block simply turns off warnings by saving the current
481 setting of C<$^W> and then setting it to zero. The second one initializes
482 the debugger variables that are needed before the debugger begins executing.
483 The third one puts C<$^X> back to its former value.
485 We'll detail the second C<BEGIN> block later; just remember that if you need
486 to initialize something before the debugger starts really executing, that's
495 # Debugger for Perl 5.00x; perl5db.pl patch level:
498 $header = "perl5db.pl version $VERSION";
500 =head1 DEBUGGER ROUTINES
504 This function replaces straight C<eval()> inside the debugger; it simplifies
505 the process of evaluating code in the user's context.
507 The code to be evaluated is passed via the package global variable
508 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
510 We preserve the current settings of X<C<$trace>>, X<C<$single>>, and X<C<$^D>>;
511 add the X<C<$usercontext>> (that's the preserved values of C<$@>, C<$!>,
512 C<$^E>, C<$,>, C<$/>, C<$\>, and C<$^W>, grabbed when C<DB::DB> got control,
513 and the user's current package) and a add a newline before we do the C<eval()>.
514 This causes the proper context to be used when the eval is actually done.
515 Afterward, we restore C<$trace>, C<$single>, and C<$^D>.
517 Next we need to handle C<$@> without getting confused. We save C<$@> in a
518 local lexical, localize C<$saved[0]> (which is where C<save()> will put
519 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
520 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
521 considered sane by the debugger. If there was an C<eval()> error, we print
522 it on the debugger's output. If X<C<$onetimedump>> is defined, we call
523 X<C<dumpit>> if it's set to 'dump', or X<C<methods>> if it's set to
524 'methods'. Setting it to something else causes the debugger to do the eval
525 but not print the result - handy if you want to do something else with it
526 (the "watch expressions" code does this to get the value of the watch
527 expression but not show it unless it matters).
529 In any case, we then return the list of output from C<eval> to the caller,
530 and unwinding restores the former version of C<$@> in C<@saved> as well
531 (the localization of C<$saved[0]> goes away at the end of this scope).
533 =head3 Parameters and variables influencing execution of DB::eval()
535 C<DB::eval> isn't parameterized in the standard way; this is to keep the
536 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
537 The variables listed below influence C<DB::eval()>'s execution directly.
541 =item C<$evalarg> - the thing to actually be eval'ed
543 =item C<$trace> - Current state of execution tracing (see X<$trace>)
545 =item C<$single> - Current state of single-stepping (see X<$single>)
547 =item C<$onetimeDump> - what is to be displayed after the evaluation
549 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
553 The following variables are altered by C<DB::eval()> during its execution. They
554 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
558 =item C<@res> - used to capture output from actual C<eval>.
560 =item C<$otrace> - saved value of C<$trace>.
562 =item C<$osingle> - saved value of C<$single>.
564 =item C<$od> - saved value of C<$^D>.
566 =item C<$saved[0]> - saved value of C<$@>.
568 =item $\ - for output of C<$@> if there is an evaluation error.
572 =head3 The problem of lexicals
574 The context of C<DB::eval()> presents us with some problems. Obviously,
575 we want to be 'sandboxed' away from the debugger's internals when we do
576 the eval, but we need some way to control how punctuation variables and
577 debugger globals are used.
579 We can't use local, because the code inside C<DB::eval> can see localized
580 variables; and we can't use C<my> either for the same reason. The code
581 in this routine compromises and uses C<my>.
583 After this routine is over, we don't have user code executing in the debugger's
584 context, so we can use C<my> freely.
588 ############################################## Begin lexical danger zone
590 # 'my' variables used here could leak into (that is, be visible in)
591 # the context that the code being evaluated is executing in. This means that
592 # the code could modify the debugger's variables.
594 # Fiddling with the debugger's context could be Bad. We insulate things as
599 # 'my' would make it visible from user code
600 # but so does local! --tchrist
601 # Remember: this localizes @DB::res, not @main::res.
605 # Try to keep the user code from messing with us. Save these so that
606 # even if the eval'ed code changes them, we can put them back again.
607 # Needed because the user could refer directly to the debugger's
608 # package globals (and any 'my' variables in this containing scope)
609 # inside the eval(), and we want to try to stay safe.
610 local $otrace = $trace;
611 local $osingle = $single;
614 # Untaint the incoming eval() argument.
615 { ($evalarg) = $evalarg =~ /(.*)/s; }
617 # $usercontext built in DB::DB near the comment
618 # "set up the context for DB::eval ..."
619 # Evaluate and save any results.
620 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
622 # Restore those old values.
628 # Save the current value of $@, and preserve it in the debugger's copy
629 # of the saved precious globals.
632 # Since we're only saving $@, we only have to localize the array element
633 # that it will be stored in.
634 local $saved[0]; # Preserve the old value of $@
637 # Now see whether we need to report an error back to the user.
643 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
644 # are package globals.
645 elsif ($onetimeDump) {
646 if ( $onetimeDump eq 'dump' ) {
647 local $option{dumpDepth} = $onetimedumpDepth
648 if defined $onetimedumpDepth;
649 dumpit( $OUT, \@res );
651 elsif ( $onetimeDump eq 'methods' ) {
654 } ## end elsif ($onetimeDump)
658 ############################################## End lexical danger zone
660 # After this point it is safe to introduce lexicals.
661 # The code being debugged will be executing in its own context, and
662 # can't see the inside of the debugger.
664 # However, one should not overdo it: leave as much control from outside as
665 # possible. If you make something a lexical, it's not going to be addressable
666 # from outside the debugger even if you know its name.
668 # This file is automatically included if you do perl -d.
669 # It's probably not useful to include this yourself.
671 # Before venturing further into these twisty passages, it is
672 # wise to read the perldebguts man page or risk the ire of dragons.
674 # (It should be noted that perldebguts will tell you a lot about
675 # the underlying mechanics of how the debugger interfaces into the
676 # Perl interpreter, but not a lot about the debugger itself. The new
677 # comments in this code try to address this problem.)
679 # Note that no subroutine call is possible until &DB::sub is defined
680 # (for subroutines defined outside of the package DB). In fact the same is
681 # true if $deep is not defined.
683 # $Log: perldb.pl,v $
685 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
687 # modified Perl debugger, to be run from Emacs in perldb-mode
688 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
689 # Johan Vromans -- upgrade to 4.0 pl 10
690 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
692 # (We have made efforts to clarify the comments in the change log
693 # in other places; some of them may seem somewhat obscure as they
694 # were originally written, and explaining them away from the code
695 # in question seems conterproductive.. -JM)
697 ########################################################################
699 # + A lot of things changed after 0.94. First of all, core now informs
700 # debugger about entry into XSUBs, overloaded operators, tied operations,
701 # BEGIN and END. Handy with `O f=2'.
702 # + This can make debugger a little bit too verbose, please be patient
703 # and report your problems promptly.
704 # + Now the option frame has 3 values: 0,1,2. XXX Document!
705 # + Note that if DESTROY returns a reference to the object (or object),
706 # the deletion of data may be postponed until the next function call,
707 # due to the need to examine the return value.
710 # + `v' command shows versions.
713 # + `v' command shows version of readline.
714 # primitive completion works (dynamic variables, subs for `b' and `l',
715 # options). Can `p %var'
716 # + Better help (`h <' now works). New commands <<, >>, {, {{.
717 # {dump|print}_trace() coded (to be able to do it from <<cmd).
718 # + `c sub' documented.
719 # + At last enough magic combined to stop after the end of debuggee.
720 # + !! should work now (thanks to Emacs bracket matching an extra
721 # `]' in a regexp is caught).
722 # + `L', `D' and `A' span files now (as documented).
723 # + Breakpoints in `require'd code are possible (used in `R').
724 # + Some additional words on internal work of debugger.
725 # + `b load filename' implemented.
726 # + `b postpone subr' implemented.
727 # + now only `q' exits debugger (overwritable on $inhibit_exit).
728 # + When restarting debugger breakpoints/actions persist.
729 # + Buglet: When restarting debugger only one breakpoint/action per
730 # autoloaded function persists.
732 # Changes: 0.97: NonStop will not stop in at_exit().
733 # + Option AutoTrace implemented.
734 # + Trace printed differently if frames are printed too.
735 # + new `inhibitExit' option.
736 # + printing of a very long statement interruptible.
737 # Changes: 0.98: New command `m' for printing possible methods
738 # + 'l -' is a synonym for `-'.
739 # + Cosmetic bugs in printing stack trace.
740 # + `frame' & 8 to print "expanded args" in stack trace.
741 # + Can list/break in imported subs.
742 # + new `maxTraceLen' option.
743 # + frame & 4 and frame & 8 granted.
745 # + nonstoppable lines do not have `:' near the line number.
746 # + `b compile subname' implemented.
747 # + Will not use $` any more.
748 # + `-' behaves sane now.
749 # Changes: 0.99: Completion for `f', `m'.
750 # + `m' will remove duplicate names instead of duplicate functions.
751 # + `b load' strips trailing whitespace.
752 # completion ignores leading `|'; takes into account current package
753 # when completing a subroutine name (same for `l').
754 # Changes: 1.07: Many fixed by tchrist 13-March-2000
756 # + Added bare minimal security checks on perldb rc files, plus
757 # comments on what else is needed.
758 # + Fixed the ornaments that made "|h" completely unusable.
759 # They are not used in print_help if they will hurt. Strip pod
760 # if we're paging to less.
761 # + Fixed mis-formatting of help messages caused by ornaments
762 # to restore Larry's original formatting.
763 # + Fixed many other formatting errors. The code is still suboptimal,
764 # and needs a lot of work at restructuring. It's also misindented
766 # + Fixed bug where trying to look at an option like your pager
768 # + Fixed some $? processing. Note: if you use csh or tcsh, you will
769 # lose. You should consider shell escapes not using their shell,
770 # or else not caring about detailed status. This should really be
771 # unified into one place, too.
772 # + Fixed bug where invisible trailing whitespace on commands hoses you,
773 # tricking Perl into thinking you weren't calling a debugger command!
774 # + Fixed bug where leading whitespace on commands hoses you. (One
775 # suggests a leading semicolon or any other irrelevant non-whitespace
776 # to indicate literal Perl code.)
777 # + Fixed bugs that ate warnings due to wrong selected handle.
778 # + Fixed a precedence bug on signal stuff.
779 # + Fixed some unseemly wording.
780 # + Fixed bug in help command trying to call perl method code.
781 # + Fixed to call dumpvar from exception handler. SIGPIPE killed us.
783 # + Added some comments. This code is still nasty spaghetti.
784 # + Added message if you clear your pre/post command stacks which was
785 # very easy to do if you just typed a bare >, <, or {. (A command
786 # without an argument should *never* be a destructive action; this
787 # API is fundamentally screwed up; likewise option setting, which
788 # is equally buggered.)
789 # + Added command stack dump on argument of "?" for >, <, or {.
790 # + Added a semi-built-in doc viewer command that calls man with the
791 # proper %Config::Config path (and thus gets caching, man -k, etc),
792 # or else perldoc on obstreperous platforms.
793 # + Added to and rearranged the help information.
794 # + Detected apparent misuse of { ... } to declare a block; this used
795 # to work but now is a command, and mysteriously gave no complaint.
797 # Changes: 1.08: Apr 25, 2001 Jon Eveland <jweveland@yahoo.com>
799 # + This patch to perl5db.pl cleans up formatting issues on the help
800 # summary (h h) screen in the debugger. Mostly columnar alignment
801 # issues, plus converted the printed text to use all spaces, since
802 # tabs don't seem to help much here.
804 # Changes: 1.09: May 19, 2001 Ilya Zakharevich <ilya@math.ohio-state.edu>
805 # Minor bugs corrected;
806 # + Support for auto-creation of new TTY window on startup, either
807 # unconditionally, or if started as a kid of another debugger session;
808 # + New `O'ption CreateTTY
809 # I<CreateTTY> bits control attempts to create a new TTY on events:
811 # 2: debugger is started inside debugger
813 # + Code to auto-create a new TTY window on OS/2 (currently one
814 # extra window per session - need named pipes to have more...);
815 # + Simplified interface for custom createTTY functions (with a backward
816 # compatibility hack); now returns the TTY name to use; return of ''
817 # means that the function reset the I/O handles itself;
818 # + Better message on the semantic of custom createTTY function;
819 # + Convert the existing code to create a TTY into a custom createTTY
821 # + Consistent support for TTY names of the form "TTYin,TTYout";
822 # + Switch line-tracing output too to the created TTY window;
823 # + make `b fork' DWIM with CORE::GLOBAL::fork;
824 # + High-level debugger API cmd_*():
825 # cmd_b_load($filenamepart) # b load filenamepart
826 # cmd_b_line($lineno [, $cond]) # b lineno [cond]
827 # cmd_b_sub($sub [, $cond]) # b sub [cond]
828 # cmd_stop() # Control-C
829 # cmd_d($lineno) # d lineno (B)
830 # The cmd_*() API returns FALSE on failure; in this case it outputs
831 # the error message to the debugging output.
832 # + Low-level debugger API
833 # break_on_load($filename) # b load filename
834 # @files = report_break_on_load() # List files with load-breakpoints
835 # breakable_line_in_filename($name, $from [, $to])
836 # # First breakable line in the
837 # # range $from .. $to. $to defaults
838 # # to $from, and may be less than
840 # breakable_line($from [, $to]) # Same for the current file
841 # break_on_filename_line($name, $lineno [, $cond])
842 # # Set breakpoint,$cond defaults to
844 # break_on_filename_line_range($name, $from, $to [, $cond])
845 # # As above, on the first
846 # # breakable line in range
847 # break_on_line($lineno [, $cond]) # As above, in the current file
848 # break_subroutine($sub [, $cond]) # break on the first breakable line
849 # ($name, $from, $to) = subroutine_filename_lines($sub)
850 # # The range of lines of the text
851 # The low-level API returns TRUE on success, and die()s on failure.
853 # Changes: 1.10: May 23, 2001 Daniel Lewart <d-lewart@uiuc.edu>
855 # + Fixed warnings generated by "perl -dWe 42"
856 # + Corrected spelling errors
857 # + Squeezed Help (h) output into 80 columns
859 # Changes: 1.11: May 24, 2001 David Dyck <dcd@tc.fluke.com>
860 # + Made "x @INC" work like it used to
862 # Changes: 1.12: May 24, 2001 Daniel Lewart <d-lewart@uiuc.edu>
863 # + Fixed warnings generated by "O" (Show debugger options)
864 # + Fixed warnings generated by "p 42" (Print expression)
865 # Changes: 1.13: Jun 19, 2001 Scott.L.Miller@compaq.com
866 # + Added windowSize option
867 # Changes: 1.14: Oct 9, 2001 multiple
868 # + Clean up after itself on VMS (Charles Lane in 12385)
869 # + Adding "@ file" syntax (Peter Scott in 12014)
870 # + Debug reloading selfloaded stuff (Ilya Zakharevich in 11457)
871 # + $^S and other debugger fixes (Ilya Zakharevich in 11120)
872 # + Forgot a my() declaration (Ilya Zakharevich in 11085)
873 # Changes: 1.15: Nov 6, 2001 Michael G Schwern <schwern@pobox.com>
874 # + Updated 1.14 change log
875 # + Added *dbline explainatory comments
876 # + Mentioning perldebguts man page
877 # Changes: 1.16: Feb 15, 2002 Mark-Jason Dominus <mjd@plover.com>
878 # + $onetimeDump improvements
879 # Changes: 1.17: Feb 20, 2002 Richard Foley <richard.foley@rfi.net>
880 # Moved some code to cmd_[.]()'s for clarity and ease of handling,
881 # rationalised the following commands and added cmd_wrapper() to
882 # enable switching between old and frighteningly consistent new
883 # behaviours for diehards: 'o CommandSet=pre580' (sigh...)
884 # a(add), A(del) # action expr (added del by line)
885 # + b(add), B(del) # break [line] (was b,D)
886 # + w(add), W(del) # watch expr (was W,W)
887 # # added del by expr
888 # + h(summary), h h(long) # help (hh) (was h h,h)
889 # + m(methods), M(modules) # ... (was m,v)
890 # + o(option) # lc (was O)
891 # + v(view code), V(view Variables) # ... (was w,V)
892 # Changes: 1.18: Mar 17, 2002 Richard Foley <richard.foley@rfi.net>
893 # + fixed missing cmd_O bug
894 # Changes: 1.19: Mar 29, 2002 Spider Boardman
895 # + Added missing local()s -- DB::DB is called recursively.
896 # Changes: 1.20: Feb 17, 2003 Richard Foley <richard.foley@rfi.net>
897 # + pre'n'post commands no longer trashed with no args
898 # + watch val joined out of eval()
899 # Changes: 1.21: Jun 04, 2003 Joe McMahon <mcmahon@ibiblio.org>
900 # + Added comments and reformatted source. No bug fixes/enhancements.
901 # + Includes cleanup by Robin Barker and Jarkko Hietaniemi.
902 # Changes: 1.22 Jun 09, 2003 Alex Vandiver <alexmv@MIT.EDU>
903 # + Flush stdout/stderr before the debugger prompt is printed.
904 # Changes: 1.23: Dec 21, 2003 Dominique Quatravaux
905 # + Fix a side-effect of bug #24674 in the perl debugger ("odd taint bug")
906 # Changes: 1.24: Mar 03, 2004 Richard Foley <richard.foley@rfi.net>
907 # + Added command to save all debugger commands for sourcing later.
908 # + Added command to display parent inheritence tree of given class.
909 # + Fixed minor newline in history bug.
910 # Changes: 1.25: Apr 17, 2004 Richard Foley <richard.foley@rfi.net>
911 # + Fixed option bug (setting invalid options + not recognising valid short forms)
912 # Changes: 1.26: Apr 22, 2004 Richard Foley <richard.foley@rfi.net>
913 # + unfork the 5.8.x and 5.9.x debuggers.
914 # + whitespace and assertions call cleanup across versions
915 # + H * deletes (resets) history
916 # + i now handles Class + blessed objects
917 # Changes: 1.27: May 09, 2004 Richard Foley <richard.foley@rfi.net>
918 # + updated pod page references - clunky.
919 # + removed windowid restriction for forking into an xterm.
920 # + more whitespace again.
921 # + wrapped restart and enabled rerun [-n] (go back n steps) command.
922 ####################################################################
924 =head1 DEBUGGER INITIALIZATION
926 The debugger starts up in phases.
930 First, it initializes the environment it wants to run in: turning off
931 warnings during its own compilation, defining variables which it will need
932 to avoid warnings later, setting itself up to not exit when the program
933 terminates, and defaulting to printing return values for the C<r> command.
937 # Needed for the statement after exec():
939 # This BEGIN block is simply used to switch off warnings during debugger
940 # compiliation. Probably it would be better practice to fix the warnings,
941 # but this is how it's done at the moment.
946 } # Switch compilation warnings off until another BEGIN.
948 # test if assertions are supported and actived:
950 $ini_assertion = eval "sub asserting_test : assertion {1}; 1";
952 # $ini_assertion = undef => assertions unsupported,
953 # " = 1 => assertions supported
954 # print "\$ini_assertion=$ini_assertion\n";
957 local ($^W) = 0; # Switch run-time warnings off during init.
959 # This would probably be better done with "use vars", but that wasn't around
960 # when this code was originally written. (Neither was "use strict".) And on
961 # the principle of not fiddling with something that was working, this was
964 # These variables control the execution of 'dumpvar.pl'.
966 $dumpvar::arrayDepth,
967 $dumpvar::dumpDBFiles,
968 $dumpvar::dumpPackages,
969 $dumpvar::quoteHighBit,
970 $dumpvar::printUndef,
974 # used to save @ARGV and extract any debugger-related flags.
977 # used to control die() reporting in diesignal()
980 # used to prevent multiple entries to diesignal()
981 # (if for instance diesignal() itself dies)
984 # used to prevent the debugger from running nonstop
990 # Command-line + PERLLIB:
991 # Save the contents of @INC before they are modified elsewhere.
994 # This was an attempt to clear out the previous values of various
995 # trapped errors. Apparently it didn't help. XXX More info needed!
996 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
998 # We set these variables to safe values. We don't want to blindly turn
999 # off warnings, because other packages may still want them.
1000 $trace = $signal = $single = 0; # Uninitialized warning suppression
1001 # (local $^W cannot help - other packages!).
1003 # Default to not exiting when program finishes; print the return
1004 # value when the 'r' command is used to return from a subroutine.
1005 $inhibit_exit = $option{PrintRet} = 1;
1007 =head1 OPTION PROCESSING
1009 The debugger's options are actually spread out over the debugger itself and
1010 C<dumpvar.pl>; some of these are variables to be set, while others are
1011 subs to be called with a value. To try to make this a little easier to
1012 manage, the debugger uses a few data structures to define what options
1013 are legal and how they are to be processed.
1015 First, the C<@options> array defines the I<names> of all the options that
1022 hashDepth arrayDepth dumpDepth
1023 DumpDBFiles DumpPackages DumpReused
1024 compactDump veryCompact quote
1025 HighBit undefPrint globPrint
1026 PrintRet UsageOnly frame
1028 ReadLine NonStop LineInfo
1029 maxTraceLen recallCommand ShellBang
1030 pager tkRunning ornaments
1031 signalLevel warnLevel dieLevel
1032 inhibit_exit ImmediateStop bareStringify
1033 CreateTTY RemotePort windowSize
1034 DollarCaretP OnlyAssertions WarnAssertions
1037 @RememberOnROptions = qw(DollarCaretP OnlyAssertions);
1041 Second, C<optionVars> lists the variables that each option uses to save its
1047 hashDepth => \$dumpvar::hashDepth,
1048 arrayDepth => \$dumpvar::arrayDepth,
1049 CommandSet => \$CommandSet,
1050 DumpDBFiles => \$dumpvar::dumpDBFiles,
1051 DumpPackages => \$dumpvar::dumpPackages,
1052 DumpReused => \$dumpvar::dumpReused,
1053 HighBit => \$dumpvar::quoteHighBit,
1054 undefPrint => \$dumpvar::printUndef,
1055 globPrint => \$dumpvar::globPrint,
1056 UsageOnly => \$dumpvar::usageOnly,
1057 CreateTTY => \$CreateTTY,
1058 bareStringify => \$dumpvar::bareStringify,
1060 AutoTrace => \$trace,
1061 inhibit_exit => \$inhibit_exit,
1062 maxTraceLen => \$maxtrace,
1063 ImmediateStop => \$ImmediateStop,
1064 RemotePort => \$remoteport,
1065 windowSize => \$window,
1066 WarnAssertions => \$warnassertions,
1071 Third, C<%optionAction> defines the subroutine to be called to process each
1077 compactDump => \&dumpvar::compactDump,
1078 veryCompact => \&dumpvar::veryCompact,
1079 quote => \&dumpvar::quote,
1082 ReadLine => \&ReadLine,
1083 NonStop => \&NonStop,
1084 LineInfo => \&LineInfo,
1085 recallCommand => \&recallCommand,
1086 ShellBang => \&shellBang,
1088 signalLevel => \&signalLevel,
1089 warnLevel => \&warnLevel,
1090 dieLevel => \&dieLevel,
1091 tkRunning => \&tkRunning,
1092 ornaments => \&ornaments,
1093 RemotePort => \&RemotePort,
1094 DollarCaretP => \&DollarCaretP,
1095 OnlyAssertions=> \&OnlyAssertions,
1100 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1105 # Note that this list is not complete: several options not listed here
1106 # actually require that dumpvar.pl be loaded for them to work, but are
1107 # not in the table. A subsequent patch will correct this problem; for
1108 # the moment, we're just recommenting, and we are NOT going to change
1111 compactDump => 'dumpvar.pl',
1112 veryCompact => 'dumpvar.pl',
1113 quote => 'dumpvar.pl',
1118 There are a number of initialization-related variables which can be set
1119 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1120 variable. These are:
1124 =item C<$rl> - readline control XXX needs more explanation
1126 =item C<$warnLevel> - whether or not debugger takes over warning handling
1128 =item C<$dieLevel> - whether or not debugger takes over die handling
1130 =item C<$signalLevel> - whether or not debugger takes over signal handling
1132 =item C<$pre> - preprompt actions (array reference)
1134 =item C<$post> - postprompt actions (array reference)
1138 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1140 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1146 # These guys may be defined in $ENV{PERL5DB} :
1147 $rl = 1 unless defined $rl;
1148 $warnLevel = 1 unless defined $warnLevel;
1149 $dieLevel = 1 unless defined $dieLevel;
1150 $signalLevel = 1 unless defined $signalLevel;
1151 $pre = [] unless defined $pre;
1152 $post = [] unless defined $post;
1153 $pretype = [] unless defined $pretype;
1154 $CreateTTY = 3 unless defined $CreateTTY;
1155 $CommandSet = '580' unless defined $CommandSet;
1159 The default C<die>, C<warn>, and C<signal> handlers are set up.
1163 warnLevel($warnLevel);
1164 dieLevel($dieLevel);
1165 signalLevel($signalLevel);
1169 The pager to be used is needed next. We try to get it from the
1170 environment first. if it's not defined there, we try to find it in
1171 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1172 then call the C<pager()> function to save the pager name.
1176 # This routine makes sure $pager is set up so that '|' can use it.
1179 # If PAGER is defined in the environment, use it.
1183 # If not, see if Config.pm defines it.
1184 : eval { require Config }
1185 && defined $Config::Config{pager}
1186 ? $Config::Config{pager}
1188 # If not, fall back to 'more'.
1191 unless defined $pager;
1195 We set up the command to be used to access the man pages, the command
1196 recall character ("!" unless otherwise defined) and the shell escape
1197 character ("!" unless otherwise defined). Yes, these do conflict, and
1198 neither works in the debugger at the moment.
1204 # Set up defaults for command recall and shell escape (note:
1205 # these currently don't work in linemode debugging).
1206 &recallCommand("!") unless defined $prc;
1207 &shellBang("!") unless defined $psh;
1211 We then set up the gigantic string containing the debugger help.
1212 We also set the limit on the number of arguments we'll display during a
1219 # If we didn't get a default for the length of eval/stack trace args,
1221 $maxtrace = 400 unless defined $maxtrace;
1223 =head2 SETTING UP THE DEBUGGER GREETING
1225 The debugger 'greeting' helps to inform the user how many debuggers are
1226 running, and whether the current debugger is the primary or a child.
1228 If we are the primary, we just hang onto our pid so we'll have it when
1229 or if we start a child debugger. If we are a child, we'll set things up
1230 so we'll have a unique greeting and so the parent will give us our own
1233 We save the current contents of the C<PERLDB_PIDS> environment variable
1234 because we mess around with it. We'll also need to hang onto it because
1235 we'll need it if we restart.
1237 Child debuggers make a label out of the current PID structure recorded in
1238 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1239 yet so the parent will give them one later via C<resetterm()>.
1243 # Save the current contents of the environment; we're about to
1244 # much with it. We'll need this if we have to restart.
1245 $ini_pids = $ENV{PERLDB_PIDS};
1247 if ( defined $ENV{PERLDB_PIDS} ) {
1249 # We're a child. Make us a label out of the current PID structure
1250 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1251 # a term yet so the parent will give us one later via resetterm().
1252 $pids = "[$ENV{PERLDB_PIDS}]";
1253 $ENV{PERLDB_PIDS} .= "->$$";
1255 } ## end if (defined $ENV{PERLDB_PIDS...
1258 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1259 # child debugger, and mark us as the parent, so we'll know to set up
1260 # more TTY's is we have to.
1261 $ENV{PERLDB_PIDS} = "$$";
1268 # Sets up $emacs as a synonym for $slave_editor.
1269 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1271 =head2 READING THE RC FILE
1273 The debugger will read a file of initialization options if supplied. If
1274 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1278 # As noted, this test really doesn't check accurately that the debugger
1279 # is running at a terminal or not.
1281 if ( -e "/dev/tty" ) { # this is the wrong metric!
1282 $rcfile = ".perldb";
1285 $rcfile = "perldb.ini";
1290 The debugger does a safety test of the file to be read. It must be owned
1291 either by the current user or root, and must only be writable by the owner.
1295 # This wraps a safety test around "do" to read and evaluate the init file.
1297 # This isn't really safe, because there's a race
1298 # between checking and opening. The solution is to
1299 # open and fstat the handle, but then you have to read and
1300 # eval the contents. But then the silly thing gets
1301 # your lexical scope, which is unfortunate at best.
1305 # Just exactly what part of the word "CORE::" don't you understand?
1306 local $SIG{__WARN__};
1307 local $SIG{__DIE__};
1309 unless ( is_safe_file($file) ) {
1310 CORE::warn <<EO_GRIPE;
1311 perldb: Must not source insecure rcfile $file.
1312 You or the superuser must be the owner, and it must not
1313 be writable by anyone but its owner.
1316 } ## end unless (is_safe_file($file...
1319 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1320 } ## end sub safe_do
1322 # This is the safety test itself.
1324 # Verifies that owner is either real user or superuser and that no
1325 # one but owner may write to it. This function is of limited use
1326 # when called on a path instead of upon a handle, because there are
1327 # no guarantees that filename (by dirent) whose file (by ino) is
1328 # eventually accessed is the same as the one tested.
1329 # Assumes that the file's existence is not in doubt.
1332 stat($path) || return; # mysteriously vaporized
1333 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1335 return 0 if $uid != 0 && $uid != $<;
1336 return 0 if $mode & 022;
1338 } ## end sub is_safe_file
1340 # If the rcfile (whichever one we decided was the right one to read)
1341 # exists, we safely do it.
1343 safe_do("./$rcfile");
1346 # If there isn't one here, try the user's home directory.
1347 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1348 safe_do("$ENV{HOME}/$rcfile");
1351 # Else try the login directory.
1352 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1353 safe_do("$ENV{LOGDIR}/$rcfile");
1356 # If the PERLDB_OPTS variable has options in it, parse those out next.
1357 if ( defined $ENV{PERLDB_OPTS} ) {
1358 parse_options( $ENV{PERLDB_OPTS} );
1363 The last thing we do during initialization is determine which subroutine is
1364 to be used to obtain a new terminal when a new debugger is started. Right now,
1365 the debugger only handles X Windows and OS/2.
1369 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1370 # Works if you're running an xterm or xterm-like window, or you're on
1371 # OS/2. This may need some expansion: for instance, this doesn't handle
1372 # OS X Terminal windows.
1375 not defined &get_fork_TTY # no routine exists,
1376 and defined $ENV{TERM} # and we know what kind
1377 # of terminal this is,
1378 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1379 # and defined $ENV{WINDOWID} # and we know what window this is, <- wrong metric
1380 and defined $ENV{DISPLAY} # and what display it's on,
1383 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1384 } ## end if (not defined &get_fork_TTY...
1385 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1386 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1389 # untaint $^O, which may have been tainted by the last statement.
1390 # see bug [perl #24674]
1394 # Here begin the unreadable code. It needs fixing.
1396 =head2 RESTART PROCESSING
1398 This section handles the restart command. When the C<R> command is invoked, it
1399 tries to capture all of the state it can into environment variables, and
1400 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1401 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1402 the R command stuffed into the environment variables.
1404 PERLDB_RESTART - flag only, contains no restart data itself.
1405 PERLDB_HIST - command history, if it's available
1406 PERLDB_ON_LOAD - breakpoints set by the rc file
1407 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1408 PERLDB_VISITED - files that had breakpoints
1409 PERLDB_FILE_... - breakpoints for a file
1410 PERLDB_OPT - active options
1411 PERLDB_INC - the original @INC
1412 PERLDB_PRETYPE - preprompt debugger actions
1413 PERLDB_PRE - preprompt Perl code
1414 PERLDB_POST - post-prompt Perl code
1415 PERLDB_TYPEAHEAD - typeahead captured by readline()
1417 We chug through all these variables and plug the values saved in them
1418 back into the appropriate spots in the debugger.
1422 if ( exists $ENV{PERLDB_RESTART} ) {
1424 # We're restarting, so we don't need the flag that says to restart anymore.
1425 delete $ENV{PERLDB_RESTART};
1428 @hist = get_list('PERLDB_HIST');
1429 %break_on_load = get_list("PERLDB_ON_LOAD");
1430 %postponed = get_list("PERLDB_POSTPONE");
1432 # restore breakpoints/actions
1433 my @had_breakpoints = get_list("PERLDB_VISITED");
1434 for ( 0 .. $#had_breakpoints ) {
1435 my %pf = get_list("PERLDB_FILE_$_");
1436 $postponed_file{ $had_breakpoints[$_] } = \%pf if %pf;
1440 my %opt = get_list("PERLDB_OPT");
1442 while ( ( $opt, $val ) = each %opt ) {
1443 $val =~ s/[\\\']/\\$1/g;
1444 parse_options("$opt'$val'");
1447 # restore original @INC
1448 @INC = get_list("PERLDB_INC");
1451 # return pre/postprompt actions and typeahead buffer
1452 $pretype = [ get_list("PERLDB_PRETYPE") ];
1453 $pre = [ get_list("PERLDB_PRE") ];
1454 $post = [ get_list("PERLDB_POST") ];
1455 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1456 } ## end if (exists $ENV{PERLDB_RESTART...
1458 =head2 SETTING UP THE TERMINAL
1460 Now, we'll decide how the debugger is going to interact with the user.
1461 If there's no TTY, we set the debugger to run non-stop; there's not going
1462 to be anyone there to enter commands.
1472 If there is a TTY, we have to determine who it belongs to before we can
1473 proceed. If this is a slave editor or graphical debugger (denoted by
1474 the first command-line switch being '-emacs'), we shift this off and
1475 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1481 # Is Perl being run from a slave editor or graphical debugger?
1482 # If so, don't use readline, and set $slave_editor = 1.
1484 ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) );
1485 $rl = 0, shift(@main::ARGV) if $slave_editor;
1487 #require Term::ReadLine;
1491 We then determine what the console should be on various systems:
1495 =item * Cygwin - We use C<stdin> instead of a separate device.
1499 if ( $^O eq 'cygwin' ) {
1501 # /dev/tty is binary. use stdin for textmode
1505 =item * Unix - use C</dev/tty>.
1509 elsif ( -e "/dev/tty" ) {
1510 $console = "/dev/tty";
1513 =item * Windows or MSDOS - use C<con>.
1517 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1521 =item * MacOS - use C<Dev:Console:Perl Debug> if this is the MPW version; C<Dev:
1522 Console> if not. (Note that Mac OS X returns 'darwin', not 'MacOS'. Also note that the debugger doesn't do anything special for 'darwin'. Maybe it should.)
1526 elsif ( $^O eq 'MacOS' ) {
1527 if ( $MacPerl::Version !~ /MPW/ ) {
1529 "Dev:Console:Perl Debug"; # Separate window for application
1532 $console = "Dev:Console";
1534 } ## end elsif ($^O eq 'MacOS')
1536 =item * VMS - use C<sys$command>.
1542 # everything else is ...
1543 $console = "sys\$command";
1550 Several other systems don't use a specific console. We C<undef $console>
1551 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1552 with a slave editor, Epoc).
1556 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1558 # /dev/tty is binary. use stdin for textmode
1562 if ( $^O eq 'NetWare' ) {
1564 # /dev/tty is binary. use stdin for textmode
1568 # In OS/2, we need to use STDIN to get textmode too, even though
1569 # it pretty much looks like Unix otherwise.
1570 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1575 # EPOC also falls into the 'got to use STDIN' camp.
1576 if ( $^O eq 'epoc' ) {
1582 If there is a TTY hanging around from a parent, we use that as the console.
1586 $console = $tty if defined $tty;
1588 =head2 SOCKET HANDLING
1590 The debugger is capable of opening a socket and carrying out a debugging
1591 session over the socket.
1593 If C<RemotePort> was defined in the options, the debugger assumes that it
1594 should try to start a debugging session on that port. It builds the socket
1595 and then tries to connect the input and output filehandles to it.
1599 # Handle socket stuff.
1601 if ( defined $remoteport ) {
1603 # If RemotePort was defined in the options, connect input and output
1606 $OUT = new IO::Socket::INET(
1608 PeerAddr => $remoteport,
1611 if ( !$OUT ) { die "Unable to connect to remote host: $remoteport\n"; }
1613 } ## end if (defined $remoteport)
1617 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1618 this is probably a situation where multiple debuggers are running (for example,
1619 a backticked command that starts up another debugger). We create a new IN and
1620 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1628 # Two debuggers running (probably a system or a backtick that invokes
1629 # the debugger itself under the running one). create a new IN and OUT
1630 # filehandle, and do the necessary mojo to create a new tty if we
1631 # know how, and we can.
1632 create_IN_OUT(4) if $CreateTTY & 4;
1635 # If we have a console, check to see if there are separate ins and
1636 # outs to open. (They are assumed identiical if not.)
1638 my ( $i, $o ) = split /,/, $console;
1639 $o = $i unless defined $o;
1641 # read/write on in, or just read, or read on STDIN.
1643 || open( IN, "<$i" )
1644 || open( IN, "<&STDIN" );
1646 # read/write/create/clobber out, or write/create/clobber out,
1647 # or merge with STDERR, or merge with STDOUT.
1649 || open( OUT, ">$o" )
1650 || open( OUT, ">&STDERR" )
1651 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1653 } ## end if ($console)
1654 elsif ( not defined $console ) {
1656 # No console. Open STDIN.
1657 open( IN, "<&STDIN" );
1659 # merge with STDERR, or with STDOUT.
1660 open( OUT, ">&STDERR" )
1661 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1662 $console = 'STDIN/OUT';
1663 } ## end elsif (not defined $console)
1665 # Keep copies of the filehandles so that when the pager runs, it
1666 # can close standard input without clobbering ours.
1667 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1668 } ## end elsif (from if(defined $remoteport))
1670 # Unbuffer DB::OUT. We need to see responses right away.
1671 my $previous = select($OUT);
1672 $| = 1; # for DB::OUT
1675 # Line info goes to debugger output unless pointed elsewhere.
1676 # Pointing elsewhere makes it possible for slave editors to
1677 # keep track of file and position. We have both a filehandle
1678 # and a I/O description to keep track of.
1679 $LINEINFO = $OUT unless defined $LINEINFO;
1680 $lineinfo = $console unless defined $lineinfo;
1684 To finish initialization, we show the debugger greeting,
1685 and then call the C<afterinit()> subroutine if there is one.
1689 # Show the debugger greeting.
1690 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1691 unless ($runnonstop) {
1694 if ( $term_pid eq '-1' ) {
1695 print $OUT "\nDaughter DB session started...\n";
1698 print $OUT "\nLoading DB routines from $header\n";
1701 $slave_editor ? "enabled" : "available", ".\n"
1704 "\nEnter h or `h h' for help, or `$doccmd perldebug' for more help.\n\n";
1705 } ## end else [ if ($term_pid eq '-1')
1706 } ## end unless ($runnonstop)
1707 } ## end else [ if ($notty)
1709 # XXX This looks like a bug to me.
1710 # Why copy to @ARGS and then futz with @args?
1713 # Make sure backslashes before single quotes are stripped out, and
1714 # keep args unless they are numeric (XXX why?)
1715 # s/\'/\\\'/g; # removed while not justified understandably
1716 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1719 # If there was an afterinit() sub defined, call it. It will get
1720 # executed in our scope, so it can fiddle with debugger globals.
1721 if ( defined &afterinit ) { # May be defined in $rcfile
1725 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1728 ############################################################ Subroutines
1734 This gigantic subroutine is the heart of the debugger. Called before every
1735 statement, its job is to determine if a breakpoint has been reached, and
1736 stop if so; read commands from the user, parse them, and execute
1737 them, and hen send execution off to the next statement.
1739 Note that the order in which the commands are processed is very important;
1740 some commands earlier in the loop will actually alter the C<$cmd> variable
1741 to create other commands to be executed later. This is all highly "optimized"
1742 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1743 see what's happening in any given command.
1749 # Check for whether we should be running continuously or not.
1750 # _After_ the perl program is compiled, $single is set to 1:
1751 if ( $single and not $second_time++ ) {
1753 # Options say run non-stop. Run until we get an interrupt.
1754 if ($runnonstop) { # Disable until signal
1755 # If there's any call stack in place, turn off single
1756 # stepping into subs throughout the stack.
1757 for ( $i = 0 ; $i <= $stack_depth ; ) {
1758 $stack[ $i++ ] &= ~1;
1761 # And we are now no longer in single-step mode.
1764 # If we simply returned at this point, we wouldn't get
1765 # the trace info. Fall on through.
1767 } ## end if ($runnonstop)
1769 elsif ($ImmediateStop) {
1771 # We are supposed to stop here; XXX probably a break.
1772 $ImmediateStop = 0; # We've processed it; turn it off
1773 $signal = 1; # Simulate an interrupt to force
1774 # us into the command loop
1776 } ## end if ($single and not $second_time...
1778 # If we're in single-step mode, or an interrupt (real or fake)
1779 # has occurred, turn off non-stop mode.
1780 $runnonstop = 0 if $single or $signal;
1782 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1783 # The code being debugged may have altered them.
1786 # Since DB::DB gets called after every line, we can use caller() to
1787 # figure out where we last were executing. Sneaky, eh? This works because
1788 # caller is returning all the extra information when called from the
1790 local ( $package, $filename, $line ) = caller;
1791 local $filename_ini = $filename;
1793 # set up the context for DB::eval, so it can properly execute
1794 # code on behalf of the user. We add the package in so that the
1795 # code is eval'ed in the proper package (not in the debugger!).
1796 local $usercontext =
1797 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' . "package $package;";
1799 # Create an alias to the active file magical array to simplify
1801 local (*dbline) = $main::{ '_<' . $filename };
1803 # we need to check for pseudofiles on Mac OS (these are files
1804 # not attached to a filename, but instead stored in Dev:Pseudo)
1805 if ( $^O eq 'MacOS' && $#dbline < 0 ) {
1806 $filename_ini = $filename = 'Dev:Pseudo';
1807 *dbline = $main::{ '_<' . $filename };
1810 # Last line in the program.
1811 local $max = $#dbline;
1813 # if we have something here, see if we should break.
1815 && ( ( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1818 # Stop if the stop criterion says to just stop.
1819 if ( $stop eq '1' ) {
1823 # It's a conditional stop; eval it in the user's context and
1824 # see if we should stop. If so, remove the one-time sigil.
1826 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1828 $dbline{$line} =~ s/;9($|\0)/$1/;
1830 } ## end if ($dbline{$line} && ...
1832 # Preserve the current stop-or-not, and see if any of the W
1833 # (watch expressions) has changed.
1834 my $was_signal = $signal;
1836 # If we have any watch expressions ...
1838 for ( my $n = 0 ; $n <= $#to_watch ; $n++ ) {
1839 $evalarg = $to_watch[$n];
1840 local $onetimeDump; # Tell DB::eval() to not output results
1842 # Fix context DB::eval() wants to return an array, but
1843 # we need a scalar here.
1844 my ($val) = join( "', '", &eval );
1845 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
1848 if ( $val ne $old_watch[$n] ) {
1850 # Yep! Show the difference, and fake an interrupt.
1853 Watchpoint $n:\t$to_watch[$n] changed:
1854 old value:\t$old_watch[$n]
1857 $old_watch[$n] = $val;
1858 } ## end if ($val ne $old_watch...
1859 } ## end for (my $n = 0 ; $n <= ...
1860 } ## end if ($trace & 2)
1862 =head2 C<watchfunction()>
1864 C<watchfunction()> is a function that can be defined by the user; it is a
1865 function which will be run on each entry to C<DB::DB>; it gets the
1866 current package, filename, and line as its parameters.
1868 The watchfunction can do anything it likes; it is executing in the
1869 debugger's context, so it has access to all of the debugger's internal
1870 data structures and functions.
1872 C<watchfunction()> can control the debugger's actions. Any of the following
1873 will cause the debugger to return control to the user's program after
1874 C<watchfunction()> executes:
1878 =item * Returning a false value from the C<watchfunction()> itself.
1880 =item * Altering C<$single> to a false value.
1882 =item * Altering C<$signal> to a false value.
1884 =item * Turning off the '4' bit in C<$trace> (this also disables the
1885 check for C<watchfunction()>. This can be done with
1893 # If there's a user-defined DB::watchfunction, call it with the
1894 # current package, filename, and line. The function executes in
1896 if ( $trace & 4 ) { # User-installed watch
1898 if watchfunction( $package, $filename, $line )
1901 and not( $trace & ~4 );
1902 } ## end if ($trace & 4)
1904 # Pick up any alteration to $signal in the watchfunction, and
1905 # turn off the signal now.
1906 $was_signal = $signal;
1909 =head2 GETTING READY TO EXECUTE COMMANDS
1911 The debugger decides to take control if single-step mode is on, the
1912 C<t> command was entered, or the user generated a signal. If the program
1913 has fallen off the end, we set things up so that entering further commands
1914 won't cause trouble, and we say that the program is over.
1918 # Check to see if we should grab control ($single true,
1919 # trace set appropriately, or we got a signal).
1920 if ( $single || ( $trace & 1 ) || $was_signal ) {
1922 # Yes, grab control.
1923 if ($slave_editor) {
1925 # Tell the editor to update its position.
1926 $position = "\032\032$filename:$line:0\n";
1927 print_lineinfo($position);
1932 Special check: if we're in package C<DB::fake>, we've gone through the
1933 C<END> block at least once. We set up everything so that we can continue
1934 to enter commands and have a valid context to be in.
1938 elsif ( $package eq 'DB::fake' ) {
1940 # Fallen off the end already.
1943 Debugged program terminated. Use B<q> to quit or B<R> to restart,
1944 use B<O> I<inhibit_exit> to avoid stopping after program termination,
1945 B<h q>, B<h R> or B<h O> to get additional info.
1948 # Set the DB::eval context appropriately.
1951 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;'
1952 . "package $package;"; # this won't let them modify, alas
1953 } ## end elsif ($package eq 'DB::fake')
1957 If the program hasn't finished executing, we scan forward to the
1958 next executable line, print that out, build the prompt from the file and line
1959 number information, and print that.
1965 # Still somewhere in the midst of execution. Set up the
1967 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
1968 # Perl 5 ones (sorry, we don't print Klingon
1971 $prefix = $sub =~ /::/ ? "" : "${'package'}::";
1972 $prefix .= "$sub($filename:";
1973 $after = ( $dbline[$line] =~ /\n$/ ? '' : "\n" );
1975 # Break up the prompt if it's really long.
1976 if ( length($prefix) > 30 ) {
1977 $position = "$prefix$line):\n$line:\t$dbline[$line]$after";
1983 $position = "$prefix$line$infix$dbline[$line]$after";
1986 # Print current line info, indenting if necessary.
1988 print_lineinfo( ' ' x $stack_depth,
1989 "$line:\t$dbline[$line]$after" );
1992 print_lineinfo($position);
1995 # Scan forward, stopping at either the end or the next
1997 for ( $i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i )
2000 # Drop out on null statements, block closers, and comments.
2001 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/;
2003 # Drop out if the user interrupted us.
2006 # Append a newline if the line doesn't have one. Can happen
2007 # in eval'ed text, for instance.
2008 $after = ( $dbline[$i] =~ /\n$/ ? '' : "\n" );
2010 # Next executable line.
2011 $incr_pos = "$prefix$i$infix$dbline[$i]$after";
2012 $position .= $incr_pos;
2015 # Print it indented if tracing is on.
2016 print_lineinfo( ' ' x $stack_depth,
2017 "$i:\t$dbline[$i]$after" );
2020 print_lineinfo($incr_pos);
2022 } ## end for ($i = $line + 1 ; $i...
2023 } ## end else [ if ($slave_editor)
2024 } ## end if ($single || ($trace...
2028 If there's an action to be executed for the line we stopped at, execute it.
2029 If there are any preprompt actions, execute those as well.
2033 # If there's an action, do it now.
2034 $evalarg = $action, &eval if $action;
2036 # Are we nested another level (e.g., did we evaluate a function
2037 # that had a breakpoint in it at the debugger prompt)?
2038 if ( $single || $was_signal ) {
2040 # Yes, go down a level.
2041 local $level = $level + 1;
2043 # Do any pre-prompt actions.
2044 foreach $evalarg (@$pre) {
2048 # Complain about too much recursion if we passed the limit.
2049 print $OUT $stack_depth . " levels deep in subroutine calls!\n"
2052 # The line we're currently on. Set $incr to -1 to stay here
2053 # until we get a command that tells us to advance.
2055 $incr = -1; # for backward motion.
2057 # Tack preprompt debugger actions ahead of any actual input.
2058 @typeahead = ( @$pretype, @typeahead );
2060 =head2 WHERE ARE WE?
2062 XXX Relocate this section?
2064 The debugger normally shows the line corresponding to the current line of
2065 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2066 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2068 C<$incr> controls by how many lines the "current" line should move forward
2069 after a command is executed. If set to -1, this indicates that the "current"
2070 line shouldn't change.
2072 C<$start> is the "current" line. It is used for things like knowing where to
2073 move forwards or backwards from when doing an C<L> or C<-> command.
2075 C<$max> tells the debugger where the last line of the current file is. It's
2076 used to terminate loops most often.
2078 =head2 THE COMMAND LOOP
2080 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2085 =item * The outer part of the loop, starting at the C<CMD> label. This loop
2086 reads a command and then executes it.
2088 =item * The inner part of the loop, starting at the C<PIPE> label. This part
2089 is wholly contained inside the C<CMD> block and only executes a command.
2090 Used to handle commands running inside a pager.
2094 So why have two labels to restart the loop? Because sometimes, it's easier to
2095 have a command I<generate> another command and then re-execute the loop to do
2096 the new command. This is faster, but perhaps a bit more convoluted.
2100 # The big command dispatch loop. It keeps running until the
2101 # user yields up control again.
2103 # If we have a terminal for input, and we get something back
2104 # from readline(), keep on processing.
2108 # We have a terminal, or can get one ...
2109 ( $term || &setterm ),
2111 # ... and it belogs to this PID or we get one for this PID ...
2112 ( $term_pid == $$ or resetterm(1) ),
2114 # ... and we got a line of command input ...
2120 . ( '>' x $level ) . " "
2126 # ... try to execute the input as debugger commands.
2128 # Don't stop running.
2131 # No signal is active.
2134 # Handle continued commands (ending with \):
2135 $cmd =~ s/\\$/\n/ && do {
2136 $cmd .= &readline(" cont: ");
2140 =head4 The null command
2142 A newline entered by itself means "re-execute the last command". We grab the
2143 command out of C<$laststep> (where it was recorded previously), and copy it
2144 back into C<$cmd> to be executed below. If there wasn't any previous command,
2145 we'll do nothing below (no command will match). If there was, we also save it
2146 in the command history and fall through to allow the command parsing to pick
2151 # Empty input means repeat the last command.
2152 $cmd =~ /^$/ && ( $cmd = $laststep );
2153 chomp($cmd); # get rid of the annoying extra newline
2154 push( @hist, $cmd ) if length($cmd) > 1;
2155 push( @truehist, $cmd );
2157 # This is a restart point for commands that didn't arrive
2158 # via direct user input. It allows us to 'redo PIPE' to
2159 # re-execute command processing without reading a new command.
2161 $cmd =~ s/^\s+//s; # trim annoying leading whitespace
2162 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace
2163 ($i) = split( /\s+/, $cmd );
2165 =head3 COMMAND ALIASES
2167 The debugger can create aliases for commands (these are stored in the
2168 C<%alias> hash). Before a command is executed, the command loop looks it up
2169 in the alias hash and substitutes the contents of the alias for the command,
2170 completely replacing it.
2174 # See if there's an alias for the command, and set it up if so.
2177 # Squelch signal handling; we want to keep control here
2178 # if something goes loco during the alias eval.
2179 local $SIG{__DIE__};
2180 local $SIG{__WARN__};
2182 # This is a command, so we eval it in the DEBUGGER's
2183 # scope! Otherwise, we can't see the special debugger
2184 # variables, or get to the debugger's subs. (Well, we
2185 # _could_, but why make it even more complicated?)
2186 eval "\$cmd =~ $alias{$i}";
2189 print $OUT "Couldn't evaluate `$i' alias: $@";
2192 } ## end if ($alias{$i})
2194 =head3 MAIN-LINE COMMANDS
2196 All of these commands work up to and after the program being debugged has
2201 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2202 try to execute further, cleaning any restart-related stuff out of the
2203 environment, and executing with the last value of C<$?>.
2207 $cmd =~ /^q$/ && do {
2215 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2219 $cmd =~ /^t$/ && do {
2222 print $OUT "Trace = "
2223 . ( ( $trace & 1 ) ? "on" : "off" ) . "\n";
2227 =head4 C<S> - list subroutines matching/not matching a pattern
2229 Walks through C<%sub>, checking to see whether or not to print the name.
2233 $cmd =~ /^S(\s+(!)?(.+))?$/ && do {
2235 $Srev = defined $2; # Reverse scan?
2236 $Spatt = $3; # The pattern (if any) to use.
2237 $Snocheck = !defined $1; # No args - print all subs.
2239 # Need to make these sane here.
2243 # Search through the debugger's magical hash of subs.
2244 # If $nocheck is true, just print the sub name.
2245 # Otherwise, check it against the pattern. We then use
2246 # the XOR trick to reverse the condition as required.
2247 foreach $subname ( sort( keys %sub ) ) {
2248 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2249 print $OUT $subname, "\n";
2255 =head4 C<X> - list variables in current package
2257 Since the C<V> command actually processes this, just change this to the
2258 appropriate C<V> command and fall through.
2262 $cmd =~ s/^X\b/V $package/;
2264 =head4 C<V> - list variables
2266 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2270 # Bare V commands get the currently-being-debugged package
2272 $cmd =~ /^V$/ && do {
2273 $cmd = "V $package";
2276 # V - show variables in package.
2277 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
2279 # Save the currently selected filehandle and
2280 # force output to debugger's filehandle (dumpvar
2281 # just does "print" for output).
2282 local ($savout) = select($OUT);
2284 # Grab package name and variables to dump.
2286 @vars = split( ' ', $2 );
2288 # If main::dumpvar isn't here, get it.
2289 do 'dumpvar.pl' unless defined &main::dumpvar;
2290 if ( defined &main::dumpvar ) {
2292 # We got it. Turn off subroutine entry/exit messages
2293 # for the moment, along with return values.
2297 # must detect sigpipe failures - not catching
2298 # then will cause the debugger to die.
2302 defined $option{dumpDepth}
2303 ? $option{dumpDepth}
2304 : -1, # assume -1 unless specified
2309 # The die doesn't need to include the $@, because
2310 # it will automatically get propagated for us.
2312 die unless $@ =~ /dumpvar print failed/;
2314 } ## end if (defined &main::dumpvar)
2317 # Couldn't load dumpvar.
2318 print $OUT "dumpvar.pl not available.\n";
2321 # Restore the output filehandle, and go round again.
2326 =head4 C<x> - evaluate and print an expression
2328 Hands the expression off to C<DB::eval>, setting it up to print the value
2329 via C<dumpvar.pl> instead of just printing it directly.
2333 $cmd =~ s/^x\b/ / && do { # Remainder gets done by DB::eval()
2334 $onetimeDump = 'dump'; # main::dumpvar shows the output
2336 # handle special "x 3 blah" syntax XXX propagate
2337 # doc back to special variables.
2338 if ( $cmd =~ s/^\s*(\d+)(?=\s)/ / ) {
2339 $onetimedumpDepth = $1;
2343 =head4 C<m> - print methods
2345 Just uses C<DB::methods> to determine what methods are available.
2349 $cmd =~ s/^m\s+([\w:]+)\s*$/ / && do {
2354 # m expr - set up DB::eval to do the work
2355 $cmd =~ s/^m\b/ / && do { # Rest gets done by DB::eval()
2356 $onetimeDump = 'methods'; # method output gets used there
2359 =head4 C<f> - switch files
2363 $cmd =~ /^f\b\s*(.*)/ && do {
2367 # help for no arguments (old-style was return from sub).
2370 "The old f command is now the r command.\n"; # hint
2371 print $OUT "The new f command switches filenames.\n";
2373 } ## end if (!$file)
2375 # if not in magic file list, try a close match.
2376 if ( !defined $main::{ '_<' . $file } ) {
2377 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2379 $try = substr( $try, 2 );
2380 print $OUT "Choosing $try matching `$file':\n";
2383 } ## end if (($try) = grep(m#^_<.*$file#...
2384 } ## end if (!defined $main::{ ...
2386 # If not successfully switched now, we failed.
2387 if ( !defined $main::{ '_<' . $file } ) {
2388 print $OUT "No file matching `$file' is loaded.\n";
2392 # We switched, so switch the debugger internals around.
2393 elsif ( $file ne $filename ) {
2394 *dbline = $main::{ '_<' . $file };
2399 } ## end elsif ($file ne $filename)
2401 # We didn't switch; say we didn't.
2403 print $OUT "Already in $file.\n";
2408 =head4 C<.> - return to last-executed line.
2410 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2411 and then we look up the line in the magical C<%dbline> hash.
2416 $cmd =~ /^\.$/ && do {
2417 $incr = -1; # stay at current line
2419 # Reset everything to the old location.
2421 $filename = $filename_ini;
2422 *dbline = $main::{ '_<' . $filename };
2426 print_lineinfo($position);
2430 =head4 C<-> - back one window
2432 We change C<$start> to be one window back; if we go back past the first line,
2433 we set it to be the first line. We ser C<$incr> to put us back at the
2434 currently-executing line, and then put a C<l $start +> (list one window from
2435 C<$start>) in C<$cmd> to be executed later.
2439 # - - back a window.
2440 $cmd =~ /^-$/ && do {
2442 # back up by a window; go to 1 if back too far.
2443 $start -= $incr + $window + 1;
2444 $start = 1 if $start <= 0;
2445 $incr = $window - 1;
2447 # Generate and execute a "l +" command (handled below).
2448 $cmd = 'l ' . ($start) . '+';
2451 =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>, {, {{>
2453 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2454 problems, most notably that the default case of several commands destroying
2455 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2456 retain the old commands for those who were used to using them or who preferred
2457 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2458 deal with them instead of processing them in-line.
2462 # All of these commands were remapped in perl 5.8.0;
2463 # we send them off to the secondary dispatcher (see below).
2464 $cmd =~ /^([aAbBhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so && do {
2465 &cmd_wrapper( $1, $2, $line );
2469 =head4 C<y> - List lexicals in higher scope
2471 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2472 above the current one and then displays then using C<dumpvar.pl>.
2476 $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/ && do {
2478 # See if we've got the necessary support.
2479 eval { require PadWalker; PadWalker->VERSION(0.08) }
2482 ? "PadWalker module not found - please install\n"
2487 # Load up dumpvar if we don't have it. If we can, that is.
2488 do 'dumpvar.pl' unless defined &main::dumpvar;
2489 defined &main::dumpvar
2490 or print $OUT "dumpvar.pl not available.\n"
2493 # Got all the modules we need. Find them and print them.
2494 my @vars = split( ' ', $2 || '' );
2497 my $h = eval { PadWalker::peek_my( ( $1 || 0 ) + 1 ) };
2499 # Oops. Can't find it.
2500 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2502 # Show the desired vars with dumplex().
2503 my $savout = select($OUT);
2505 # Have dumplex dump the lexicals.
2506 dumpvar::dumplex( $_, $h->{$_},
2507 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
2514 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2516 All of the commands below this point don't work after the program being
2517 debugged has ended. All of them check to see if the program has ended; this
2518 allows the commands to be relocated without worrying about a 'line of
2519 demarcation' above which commands can be entered anytime, and below which
2522 =head4 C<n> - single step, but don't trace down into subs
2524 Done by setting C<$single> to 2, which forces subs to execute straight through
2525 when entered (see X<DB::sub>). We also save the C<n> command in C<$laststep>,
2526 so a null command knows what to re-execute.
2531 $cmd =~ /^n$/ && do {
2532 end_report(), next CMD if $finished and $level <= 1;
2534 # Single step, but don't enter subs.
2537 # Save for empty command (repeat last).
2542 =head4 C<s> - single-step, entering subs
2544 Sets C<$single> to 1, which causes X<DB::sub> to continue tracing inside
2545 subs. Also saves C<s> as C<$lastcmd>.
2550 $cmd =~ /^s$/ && do {
2552 # Get out and restart the command loop if program
2554 end_report(), next CMD if $finished and $level <= 1;
2556 # Single step should enter subs.
2559 # Save for empty command (repeat last).
2564 =head4 C<c> - run continuously, setting an optional breakpoint
2566 Most of the code for this command is taken up with locating the optional
2567 breakpoint, which is either a subroutine name or a line number. We set
2568 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2569 in this and all call levels above this one.
2573 # c - start continuous execution.
2574 $cmd =~ /^c\b\s*([\w:]*)\s*$/ && do {
2576 # Hey, show's over. The debugged program finished
2577 # executing already.
2578 end_report(), next CMD if $finished and $level <= 1;
2580 # Capture the place to put a one-time break.
2583 # Probably not needed, since we finish an interactive
2584 # sub-session anyway...
2585 # local $filename = $filename;
2586 # local *dbline = *dbline; # XXX Would this work?!
2588 # The above question wonders if localizing the alias
2589 # to the magic array works or not. Since it's commented
2590 # out, we'll just leave that to speculation for now.
2592 # If the "subname" isn't all digits, we'll assume it
2593 # is a subroutine name, and try to find it.
2594 if ( $subname =~ /\D/ ) { # subroutine name
2595 # Qualify it to the current package unless it's
2596 # already qualified.
2597 $subname = $package . "::" . $subname
2598 unless $subname =~ /::/;
2600 # find_sub will return "file:line_number" corresponding
2601 # to where the subroutine is defined; we call find_sub,
2602 # break up the return value, and assign it in one
2604 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2606 # Force the line number to be numeric.
2609 # If we got a line number, we found the sub.
2612 # Switch all the debugger's internals around so
2613 # we're actually working with that file.
2615 *dbline = $main::{ '_<' . $filename };
2617 # Mark that there's a breakpoint in this file.
2618 $had_breakpoints{$filename} |= 1;
2620 # Scan forward to the first executable line
2621 # after the 'sub whatever' line.
2623 ++$i while $dbline[$i] == 0 && $i < $max;
2626 # We didn't find a sub by that name.
2628 print $OUT "Subroutine $subname not found.\n";
2631 } ## end if ($subname =~ /\D/)
2633 # At this point, either the subname was all digits (an
2634 # absolute line-break request) or we've scanned through
2635 # the code following the definition of the sub, looking
2636 # for an executable, which we may or may not have found.
2638 # If $i (which we set $subname from) is non-zero, we
2639 # got a request to break at some line somewhere. On
2640 # one hand, if there wasn't any real subroutine name
2641 # involved, this will be a request to break in the current
2642 # file at the specified line, so we have to check to make
2643 # sure that the line specified really is breakable.
2645 # On the other hand, if there was a subname supplied, the
2646 # preceeding block has moved us to the proper file and
2647 # location within that file, and then scanned forward
2648 # looking for the next executable line. We have to make
2649 # sure that one was found.
2651 # On the gripping hand, we can't do anything unless the
2652 # current value of $i points to a valid breakable line.
2657 if ( $dbline[$i] == 0 ) {
2658 print $OUT "Line $i not breakable.\n";
2662 # Yes. Set up the one-time-break sigil.
2663 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2666 # Turn off stack tracing from here up.
2667 for ( $i = 0 ; $i <= $stack_depth ; ) {
2668 $stack[ $i++ ] &= ~1;
2673 =head4 C<r> - return from a subroutine
2675 For C<r> to work properly, the debugger has to stop execution again
2676 immediately after the return is executed. This is done by forcing
2677 single-stepping to be on in the call level above the current one. If
2678 we are printing return values when a C<r> is executed, set C<$doret>
2679 appropriately, and force us out of the command loop.
2683 # r - return from the current subroutine.
2684 $cmd =~ /^r$/ && do {
2686 # Can't do anythign if the program's over.
2687 end_report(), next CMD if $finished and $level <= 1;
2689 # Turn on stack trace.
2690 $stack[$stack_depth] |= 1;
2692 # Print return value unless the stack is empty.
2693 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2697 =head4 C<T> - stack trace
2699 Just calls C<DB::print_trace>.
2703 $cmd =~ /^T$/ && do {
2704 print_trace( $OUT, 1 ); # skip DB
2708 =head4 C<w> - List window around current line.
2710 Just calls C<DB::cmd_w>.
2714 $cmd =~ /^w\b\s*(.*)/s && do { &cmd_w( 'w', $1 ); next CMD; };
2716 =head4 C<W> - watch-expression processing.
2718 Just calls C<DB::cmd_W>.
2722 $cmd =~ /^W\b\s*(.*)/s && do { &cmd_W( 'W', $1 ); next CMD; };
2724 =head4 C</> - search forward for a string in the source
2726 We take the argument and treat it as a pattern. If it turns out to be a
2727 bad one, we return the error we got from trying to C<eval> it and exit.
2728 If not, we create some code to do the search and C<eval> it so it can't
2733 $cmd =~ /^\/(.*)$/ && do {
2735 # The pattern as a string.
2738 # Remove the final slash.
2739 $inpat =~ s:([^\\])/$:$1:;
2741 # If the pattern isn't null ...
2742 if ( $inpat ne "" ) {
2744 # Turn of warn and die procesing for a bit.
2745 local $SIG{__DIE__};
2746 local $SIG{__WARN__};
2748 # Create the pattern.
2749 eval '$inpat =~ m' . "\a$inpat\a";
2752 # Oops. Bad pattern. No biscuit.
2753 # Print the eval error and go back for more
2759 } ## end if ($inpat ne "")
2761 # Set up to stop on wrap-around.
2764 # Don't move off the current line.
2767 # Done in eval so nothing breaks if the pattern
2768 # does something weird.
2771 # Move ahead one line.
2774 # Wrap if we pass the last line.
2775 $start = 1 if ($start > $max);
2777 # Stop if we have gotten back to this line again,
2778 last if ($start == $end);
2780 # A hit! (Note, though, that we are doing
2781 # case-insensitive matching. Maybe a qr//
2782 # expression would be better, so the user could
2783 # do case-sensitive matching if desired.
2784 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2785 if ($slave_editor) {
2786 # Handle proper escaping in the slave.
2787 print $OUT "\032\032$filename:$start:0\n";
2790 # Just print the line normally.
2791 print $OUT "$start:\t",$dbline[$start],"\n";
2793 # And quit since we found something.
2798 # If we wrapped, there never was a match.
2799 print $OUT "/$pat/: not found\n" if ( $start == $end );
2803 =head4 C<?> - search backward for a string in the source
2805 Same as for C</>, except the loop runs backwards.
2809 # ? - backward pattern search.
2810 $cmd =~ /^\?(.*)$/ && do {
2812 # Get the pattern, remove trailing question mark.
2814 $inpat =~ s:([^\\])\?$:$1:;
2816 # If we've got one ...
2817 if ( $inpat ne "" ) {
2819 # Turn off die & warn handlers.
2820 local $SIG{__DIE__};
2821 local $SIG{__WARN__};
2822 eval '$inpat =~ m' . "\a$inpat\a";
2826 # Ouch. Not good. Print the error.
2831 } ## end if ($inpat ne "")
2833 # Where we are now is where to stop after wraparound.
2836 # Don't move away from this line.
2839 # Search inside the eval to prevent pattern badness
2846 # Wrap if we pass the first line.
2848 $start = $max if ($start <= 0);
2850 # Quit if we get back where we started,
2851 last if ($start == $end);
2854 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2855 if ($slave_editor) {
2856 # Yep, follow slave editor requirements.
2857 print $OUT "\032\032$filename:$start:0\n";
2860 # Yep, just print normally.
2861 print $OUT "$start:\t",$dbline[$start],"\n";
2869 # Say we failed if the loop never found anything,
2870 print $OUT "?$pat?: not found\n" if ( $start == $end );
2874 =head4 C<$rc> - Recall command
2876 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2877 that the terminal supports history). It find the the command required, puts it
2878 into C<$cmd>, and redoes the loop to execute it.
2882 # $rc - recall command.
2883 $cmd =~ /^$rc+\s*(-)?(\d+)?$/ && do {
2885 # No arguments, take one thing off history.
2886 pop(@hist) if length($cmd) > 1;
2888 # Relative (- found)?
2889 # Y - index back from most recent (by 1 if bare minus)
2890 # N - go to that particular command slot or the last
2891 # thing if nothing following.
2892 $i = $1 ? ( $#hist - ( $2 || 1 ) ) : ( $2 || $#hist );
2894 # Pick out the command desired.
2897 # Print the command to be executed and restart the loop
2898 # with that command in the buffer.
2899 print $OUT $cmd, "\n";
2903 =head4 C<$sh$sh> - C<system()> command
2905 Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
2906 C<STDOUT> from getting messed up.
2910 # $sh$sh - run a shell command (if it's all ASCII).
2911 # Can't run shell commands with Unicode in the debugger, hmm.
2912 $cmd =~ /^$sh$sh\s*([\x00-\xff]*)/ && do {
2919 =head4 C<$rc I<pattern> $rc> - Search command history
2921 Another command to manipulate C<@hist>: this one searches it with a pattern.
2922 If a command is found, it is placed in C<$cmd> and executed via <redo>.
2926 # $rc pattern $rc - find a command in the history.
2927 $cmd =~ /^$rc([^$rc].*)$/ && do {
2929 # Create the pattern to use.
2932 # Toss off last entry if length is >1 (and it always is).
2933 pop(@hist) if length($cmd) > 1;
2935 # Look backward through the history.
2936 for ( $i = $#hist ; $i ; --$i ) {
2938 # Stop if we find it.
2939 last if $hist[$i] =~ /$pat/;
2945 print $OUT "No such command!\n\n";
2949 # Found it. Put it in the buffer, print it, and process it.
2951 print $OUT $cmd, "\n";
2955 =head4 C<$sh> - Invoke a shell
2957 Uses C<DB::system> to invoke a shell.
2961 # $sh - start a shell.
2962 $cmd =~ /^$sh$/ && do {
2964 # Run the user's shell. If none defined, run Bourne.
2965 # We resume execution when the shell terminates.
2966 &system( $ENV{SHELL} || "/bin/sh" );
2970 =head4 C<$sh I<command>> - Force execution of a command in a shell
2972 Like the above, but the command is passed to the shell. Again, we use
2973 C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
2977 # $sh command - start a shell and run a command in it.
2978 $cmd =~ /^$sh\s*([\x00-\xff]*)/ && do {
2980 # XXX: using csh or tcsh destroys sigint retvals!
2981 #&system($1); # use this instead
2983 # use the user's shell, or Bourne if none defined.
2984 &system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
2988 =head4 C<H> - display commands in history
2990 Prints the contents of C<@hist> (if any).
2994 $cmd =~ /^H\b\s*\*/ && do {
2995 @hist = @truehist = ();
2996 print $OUT "History cleansed\n";
3000 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
3002 # Anything other than negative numbers is ignored by
3003 # the (incorrect) pattern, so this test does nothing.
3004 $end = $2 ? ( $#hist - $2 ) : 0;
3006 # Set to the minimum if less than zero.
3007 $hist = 0 if $hist < 0;
3009 # Start at the end of the array.
3010 # Stay in while we're still above the ending value.
3011 # Tick back by one each time around the loop.
3012 for ( $i = $#hist ; $i > $end ; $i-- ) {
3014 # Print the command unless it has no arguments.
3015 print $OUT "$i: ", $hist[$i], "\n"
3016 unless $hist[$i] =~ /^.?$/;
3021 =head4 C<man, doc, perldoc> - look up documentation
3023 Just calls C<runman()> to print the appropriate document.
3027 # man, perldoc, doc - show manual pages.
3028 $cmd =~ /^(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?$/ && do {
3035 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3036 the bottom of the loop.
3040 # p - print (no args): print $_.
3041 $cmd =~ s/^p$/print {\$DB::OUT} \$_/;
3043 # p - print the given expression.
3044 $cmd =~ s/^p\b/print {\$DB::OUT} /;
3046 =head4 C<=> - define command alias
3048 Manipulates C<%alias> to add or list command aliases.
3052 # = - set up a command alias.
3053 $cmd =~ s/^=\s*// && do {
3055 if ( length $cmd == 0 ) {
3057 # No args, get current aliases.
3058 @keys = sort keys %alias;
3060 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3062 # Creating a new alias. $k is alias name, $v is
3065 # can't use $_ or kill //g state
3066 for my $x ( $k, $v ) {
3068 # Escape "alarm" characters.
3072 # Substitute key for value, using alarm chars
3073 # as separators (which is why we escaped them in
3075 $alias{$k} = "s\a$k\a$v\a";
3077 # Turn off standard warn and die behavior.
3078 local $SIG{__DIE__};
3079 local $SIG{__WARN__};
3082 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3084 # Nope. Bad alias. Say so and get out.
3085 print $OUT "Can't alias $k to $v: $@\n";
3090 # We'll only list the new one.
3092 } ## end elsif (my ($k, $v) = ($cmd...
3094 # The argument is the alias to list.
3102 # Messy metaquoting: Trim the substiution code off.
3103 # We use control-G as the delimiter because it's not
3104 # likely to appear in the alias.
3105 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3108 print $OUT "$k\t= $1\n";
3110 elsif ( defined $alias{$k} ) {
3112 # Couldn't trim it off; just print the alias code.
3113 print $OUT "$k\t$alias{$k}\n";
3118 print "No alias for $k\n";
3120 } ## end for my $k (@keys)
3124 =head4 C<source> - read commands from a file.
3126 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3131 # source - read commands from a file (or pipe!) and execute.
3132 $cmd =~ /^source\s+(.*\S)/ && do {
3133 if ( open my $fh, $1 ) {
3135 # Opened OK; stick it in the list of file handles.
3141 &warn("Can't execute `$1': $!\n");
3146 =head4 C<save> - send current history to a file
3148 Takes the complete history, (not the shrunken version you see with C<H>),
3149 and saves it to the given filename, so it can be replayed using C<source>.
3151 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3155 # save source - write commands to a file for later use
3156 $cmd =~ /^save\s*(.*)$/ && do {
3157 my $file = $1 || '.perl5dbrc'; # default?
3158 if ( open my $fh, "> $file" ) {
3160 # chomp to remove extraneous newlines from source'd files
3161 chomp( my @truelist =
3162 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3164 print $fh join( "\n", @truelist );
3165 print "commands saved in $file\n";
3168 &warn("Can't save debugger commands in '$1': $!\n");
3173 =head4 C<R> - restart
3175 Restart the debugger session.
3177 =head4 C<rerun> - rerun the current session
3179 Return to any given position in the B<true>-history list
3183 # R - restart execution.
3184 # rerun - controlled restart execution.
3185 $cmd =~ /^(R|rerun\s*(.*))$/ && do {
3186 my @args = ($1 eq 'R' ? restart() : rerun($2));
3188 # Close all non-system fds for a clean restart. A more
3189 # correct method would be to close all fds that were not
3190 # open when the process started, but this seems to be
3191 # hard. See "debugger 'R'estart and open database
3192 # connections" on p5p.
3194 my $max_fd = 1024; # default if POSIX can't be loaded
3195 if (eval { require POSIX }) {
3196 $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX());
3199 if (defined $max_fd) {
3200 foreach ($^F+1 .. $max_fd-1) {
3201 next unless open FD_TO_CLOSE, "<&=$_";
3206 # And run Perl again. We use exec() to keep the
3207 # PID stable (and that way $ini_pids is still valid).
3208 exec(@args) || print $OUT "exec failed: $!\n";
3213 =head4 C<|, ||> - pipe output through the pager.
3215 FOR C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3216 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3217 pipe to the pager (restoring the output filehandles if this fails). If this
3218 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3219 set C<$signal>, sending us back into the debugger.
3221 We then trim off the pipe symbols and C<redo> the command loop at the
3222 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3227 # || - run command in the pager, with output to DB::OUT.
3228 $cmd =~ /^\|\|?\s*[^|]/ && do {
3229 if ( $pager =~ /^\|/ ) {
3231 # Default pager is into a pipe. Redirect I/O.
3232 open( SAVEOUT, ">&STDOUT" )
3233 || &warn("Can't save STDOUT");
3234 open( STDOUT, ">&OUT" )
3235 || &warn("Can't redirect STDOUT");
3236 } ## end if ($pager =~ /^\|/)
3239 # Not into a pipe. STDOUT is safe.
3240 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3243 # Fix up environment to record we have less if so.
3246 unless ( $piped = open( OUT, $pager ) ) {
3248 # Couldn't open pipe to pager.
3249 &warn("Can't pipe output to `$pager'");
3250 if ( $pager =~ /^\|/ ) {
3252 # Redirect I/O back again.
3253 open( OUT, ">&STDOUT" ) # XXX: lost message
3254 || &warn("Can't restore DB::OUT");
3255 open( STDOUT, ">&SAVEOUT" )
3256 || &warn("Can't restore STDOUT");
3258 } ## end if ($pager =~ /^\|/)
3261 # Redirect I/O. STDOUT already safe.
3262 open( OUT, ">&STDOUT" ) # XXX: lost message
3263 || &warn("Can't restore DB::OUT");
3266 } ## end unless ($piped = open(OUT,...
3268 # Set up broken-pipe handler if necessary.
3269 $SIG{PIPE} = \&DB::catch
3271 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
3273 # Save current filehandle, unbuffer out, and put it back.
3274 $selected = select(OUT);
3277 # Don't put it back if pager was a pipe.
3278 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
3280 # Trim off the pipe symbols and run the command now.
3281 $cmd =~ s/^\|+\s*//;
3285 =head3 END OF COMMAND PARSING
3287 Anything left in C<$cmd> at this point is a Perl expression that we want to
3288 evaluate. We'll always evaluate in the user's context, and fully qualify
3289 any variables we might want to address in the C<DB> package.
3293 # t - turn trace on.
3294 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3296 # s - single-step. Remember the last command was 's'.
3297 $cmd =~ s/^s\s/\$DB::single = 1;\n/ && do { $laststep = 's' };
3299 # n - single-step, but not into subs. Remember last command
3301 $cmd =~ s/^n\s/\$DB::single = 2;\n/ && do { $laststep = 'n' };
3305 # Make sure the flag that says "the debugger's running" is
3306 # still on, to make sure we get control again.
3307 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3309 # Run *our* eval that executes in the caller's context.
3312 # Turn off the one-time-dump stuff now.
3314 $onetimeDump = undef;
3315 $onetimedumpDepth = undef;
3317 elsif ( $term_pid == $$ ) {
3321 # XXX If this is the master pid, print a newline.
3324 } ## end while (($term || &setterm...
3326 =head3 POST-COMMAND PROCESSING
3328 After each command, we check to see if the command output was piped anywhere.
3329 If so, we go through the necessary code to unhook the pipe and go back to
3330 our standard filehandles for input and output.
3336 # At the end of every command:
3339 # Unhook the pipe mechanism now.
3340 if ( $pager =~ /^\|/ ) {
3342 # No error from the child.
3345 # we cannot warn here: the handle is missing --tchrist
3346 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
3348 # most of the $? crud was coping with broken cshisms
3349 # $? is explicitly set to 0, so this never runs.
3351 print SAVEOUT "Pager `$pager' failed: ";
3353 print SAVEOUT "shell returned -1\n";
3356 print SAVEOUT ( $? & 127 )
3357 ? " (SIG#" . ( $? & 127 ) . ")"
3358 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3361 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3365 # Reopen filehandle for our output (if we can) and
3366 # restore STDOUT (if we can).
3367 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3368 open( STDOUT, ">&SAVEOUT" )
3369 || &warn("Can't restore STDOUT");
3371 # Turn off pipe exception handler if necessary.
3372 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
3374 # Will stop ignoring SIGPIPE if done like nohup(1)
3375 # does SIGINT but Perl doesn't give us a choice.
3376 } ## end if ($pager =~ /^\|/)
3379 # Non-piped "pager". Just restore STDOUT.
3380 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3383 # Close filehandle pager was using, restore the normal one
3386 select($selected), $selected = "" unless $selected eq "";
3390 } ## end if ($piped)
3393 =head3 COMMAND LOOP TERMINATION
3395 When commands have finished executing, we come here. If the user closed the
3396 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3397 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3398 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3399 The interpreter will then execute the next line and then return control to us
3404 # No more commands? Quit.
3405 $fall_off_end = 1 unless defined $cmd; # Emulate `q' on EOF
3407 # Evaluate post-prompt commands.
3408 foreach $evalarg (@$post) {
3411 } # if ($single || $signal)
3413 # Put the user's globals back where you found them.
3414 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3418 # The following code may be executed now:
3423 C<sub> is called whenever a subroutine call happens in the program being
3424 debugged. The variable C<$DB::sub> contains the name of the subroutine
3427 The core function of this subroutine is to actually call the sub in the proper
3428 context, capturing its output. This of course causes C<DB::DB> to get called
3429 again, repeating until the subroutine ends and returns control to C<DB::sub>
3430 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3431 return value, and returns its captured copy of the return value as its own
3432 return value. The value then feeds back into the program being debugged as if
3433 C<DB::sub> hadn't been there at all.
3435 C<sub> does all the work of printing the subroutine entry and exit messages
3436 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3437 and also prints the return value if needed (for the C<r> command and if
3438 the 16 bit is set in C<$frame>).
3440 It also tracks the subroutine call depth by saving the current setting of
3441 C<$single> in the C<@stack> package global; if this exceeds the value in
3442 C<$deep>, C<sub> automatically turns on printing of the current depth by
3443 setting the 4 bit in C<$single>. In any case, it keeps the current setting
3444 of stop/don't stop on entry to subs set as it currently is set.
3446 =head3 C<caller()> support
3448 If C<caller()> is called from the package C<DB>, it provides some
3449 additional data, in the following order:
3455 The package name the sub was in
3457 =item * C<$filename>
3459 The filename it was defined in
3463 The line number it was defined on
3465 =item * C<$subroutine>
3467 The subroutine name; C<'(eval)'> if an C<eval>().
3471 1 if it has arguments, 0 if not
3473 =item * C<$wantarray>
3475 1 if array context, 0 if scalar context
3477 =item * C<$evaltext>
3479 The C<eval>() text, if any (undefined for C<eval BLOCK>)
3481 =item * C<$is_require>
3483 frame was created by a C<use> or C<require> statement
3487 pragma information; subject to change between versions
3491 pragma information: subject to change between versions
3493 =item * C<@DB::args>
3495 arguments with which the subroutine was invoked
3503 # Whether or not the autoloader was running, a scalar to put the
3504 # sub's return value in (if needed), and an array to put the sub's
3505 # return value in (if needed).
3506 my ( $al, $ret, @ret ) = "";
3508 # If the last ten characters are C'::AUTOLOAD', note we've traced
3509 # into AUTOLOAD for $sub.
3510 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3514 # We stack the stack pointer and then increment it to protect us
3515 # from a situation that might unwind a whole bunch of call frames
3516 # at once. Localizing the stack pointer means that it will automatically
3517 # unwind the same amount when multiple stack frames are unwound.
3518 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3521 $#stack = $stack_depth;
3523 # Save current single-step setting.
3524 $stack[-1] = $single;
3526 # Turn off all flags except single-stepping.
3529 # If we've gotten really deeply recursed, turn on the flag that will
3530 # make us stop with the 'deep recursion' message.
3531 $single |= 4 if $stack_depth == $deep;
3533 # If frame messages are on ...
3535 $frame & 4 # Extended frame entry message
3537 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3539 # Why -1? But it works! :-(
3540 # Because print_trace will call add 1 to it and then call
3541 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3543 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3545 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3547 # standard frame entry message
3551 # Determine the sub's return type,and capture approppriately.
3554 # Called in array context. call sub and capture output.
3555 # DB::DB will recursively get control again if appropriate; we'll come
3556 # back here when the sub is finished.
3559 eval { @ret = &$sub; };
3562 $signal = 1 unless $warnassertions;
3569 # Pop the single-step value back off the stack.
3570 $single |= $stack[ $stack_depth-- ];
3572 # Check for exit trace messages...
3574 $frame & 4 # Extended exit message
3576 print_lineinfo( ' ' x $stack_depth, "out " ),
3577 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3579 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3581 # Standard exit message
3585 # Print the return info if we need to.
3586 if ( $doret eq $stack_depth or $frame & 16 ) {
3588 # Turn off output record separator.
3590 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3592 # Indent if we're printing because of $frame tracing.
3593 print $fh ' ' x $stack_depth if $frame & 16;
3595 # Print the return value.
3596 print $fh "list context return from $sub:\n";
3597 dumpit( $fh, \@ret );
3599 # And don't print it again.
3601 } ## end if ($doret eq $stack_depth...
3602 # And we have to return the return value now.
3604 } ## end if (wantarray)
3612 # Save the value if it's wanted at all.
3617 $signal = 1 unless $warnassertions;
3619 $ret = undef unless defined wantarray;
3622 if ( defined wantarray ) {
3624 # Save the value if it's wanted at all.
3629 # Void return, explicitly.
3635 # Pop the single-step value off the stack.
3636 $single |= $stack[ $stack_depth-- ];
3638 # If we're doing exit messages...
3640 $frame & 4 # Extended messsages
3642 print_lineinfo( ' ' x $stack_depth, "out " ),
3643 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3645 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3651 # If we are supposed to show the return value... same as before.
3652 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
3654 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3655 print $fh ( ' ' x $stack_depth ) if $frame & 16;
3658 ? "scalar context return from $sub: "
3659 : "void context return from $sub\n"
3661 dumpit( $fh, $ret ) if defined wantarray;
3663 } ## end if ($doret eq $stack_depth...
3665 # Return the appropriate scalar value.
3667 } ## end else [ if (wantarray)
3670 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
3672 In Perl 5.8.0, there was a major realignment of the commands and what they did,
3673 Most of the changes were to systematize the command structure and to eliminate
3674 commands that threw away user input without checking.
3676 The following sections describe the code added to make it easy to support
3677 multiple command sets with conflicting command names. This section is a start
3678 at unifying all command processing to make it simpler to develop commands.
3680 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
3681 number, and C<$dbline> (the current line) as arguments.
3683 Support functions in this section which have multiple modes of failure C<die>
3684 on error; the rest simply return a false value.
3686 The user-interface functions (all of the C<cmd_*> functions) just output
3691 The C<%set> hash defines the mapping from command letter to subroutine
3694 C<%set> is a two-level hash, indexed by set name and then by command name.
3695 Note that trying to set the CommandSet to 'foobar' simply results in the
3696 5.8.0 command set being used, since there's no top-level entry for 'foobar'.
3705 'A' => 'pre580_null',
3707 'B' => 'pre580_null',
3708 'd' => 'pre580_null',
3711 'M' => 'pre580_null',
3713 'o' => 'pre580_null',
3719 '<' => 'pre590_prepost',
3720 '<<' => 'pre590_prepost',
3721 '>' => 'pre590_prepost',
3722 '>>' => 'pre590_prepost',
3723 '{' => 'pre590_prepost',
3724 '{{' => 'pre590_prepost',
3728 =head2 C<cmd_wrapper()> (API)
3730 C<cmd_wrapper()> allows the debugger to switch command sets
3731 depending on the value of the C<CommandSet> option.
3733 It tries to look up the command in the X<C<%set>> package-level I<lexical>
3734 (which means external entities can't fiddle with it) and create the name of
3735 the sub to call based on the value found in the hash (if it's there). I<All>
3736 of the commands to be handled in a set have to be added to C<%set>; if they
3737 aren't found, the 5.8.0 equivalent is called (if there is one).
3739 This code uses symbolic references.
3746 my $dblineno = shift;
3748 # Assemble the command subroutine's name by looking up the
3749 # command set and command name in %set. If we can't find it,
3750 # default to the older version of the command.
3752 . ( $set{$CommandSet}{$cmd}
3753 || ( $cmd =~ /^[<>{]+/o ? 'prepost' : $cmd ) );
3755 # Call the command subroutine, call it by name.
3756 return &$call( $cmd, $line, $dblineno );
3757 } ## end sub cmd_wrapper
3759 =head3 C<cmd_a> (command)
3761 The C<a> command handles pre-execution actions. These are associated with a
3762 particular line, so they're stored in C<%dbline>. We default to the current
3763 line if none is specified.
3769 my $line = shift || ''; # [.|line] expr
3772 # If it's dot (here), or not all digits, use the current line.
3773 $line =~ s/^(\.|(?:[^\d]))/$dbline/;
3775 # Should be a line number followed by an expression.
3776 if ( $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
3777 my ( $lineno, $expr ) = ( $1, $2 );
3779 # If we have an expression ...
3780 if ( length $expr ) {
3782 # ... but the line isn't breakable, complain.
3783 if ( $dbline[$lineno] == 0 ) {
3785 "Line $lineno($dbline[$lineno]) does not have an action?\n";
3789 # It's executable. Record that the line has an action.
3790 $had_breakpoints{$filename} |= 2;
3792 # Remove any action, temp breakpoint, etc.
3793 $dbline{$lineno} =~ s/\0[^\0]*//;
3795 # Add the action to the line.
3796 $dbline{$lineno} .= "\0" . action($expr);
3798 } ## end if (length $expr)
3799 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
3804 "Adding an action requires an optional lineno and an expression\n"
3809 =head3 C<cmd_A> (command)
3811 Delete actions. Similar to above, except the delete code is in a separate
3812 subroutine, C<delete_action>.
3818 my $line = shift || '';
3822 $line =~ s/^\./$dbline/;
3824 # Call delete_action with a null param to delete them all.
3825 # The '1' forces the eval to be true. It'll be false only
3826 # if delete_action blows up for some reason, in which case
3827 # we print $@ and get out.
3828 if ( $line eq '*' ) {
3829 eval { &delete_action(); 1 } or print $OUT $@ and return;
3832 # There's a real line number. Pass it to delete_action.
3833 # Error trapping is as above.
3834 elsif ( $line =~ /^(\S.*)/ ) {
3835 eval { &delete_action($1); 1 } or print $OUT $@ and return;
3838 # Swing and a miss. Bad syntax.
3841 "Deleting an action requires a line number, or '*' for all\n" ; # hint
3845 =head3 C<delete_action> (API)
3847 C<delete_action> accepts either a line number or C<undef>. If a line number
3848 is specified, we check for the line being executable (if it's not, it
3849 couldn't have had an action). If it is, we just take the action off (this
3850 will get any kind of an action, including breakpoints).
3856 if ( defined($i) ) {
3859 die "Line $i has no action .\n" if $dbline[$i] == 0;
3861 # Nuke whatever's there.
3862 $dbline{$i} =~ s/\0[^\0]*//; # \^a
3863 delete $dbline{$i} if $dbline{$i} eq '';
3866 print $OUT "Deleting all actions...\n";
3867 for my $file ( keys %had_breakpoints ) {
3868 local *dbline = $main::{ '_<' . $file };
3871 for ( $i = 1 ; $i <= $max ; $i++ ) {
3872 if ( defined $dbline{$i} ) {
3873 $dbline{$i} =~ s/\0[^\0]*//;
3874 delete $dbline{$i} if $dbline{$i} eq '';
3876 unless ( $had_breakpoints{$file} &= ~2 ) {
3877 delete $had_breakpoints{$file};
3879 } ## end for ($i = 1 ; $i <= $max...
3880 } ## end for my $file (keys %had_breakpoints)
3881 } ## end else [ if (defined($i))
3882 } ## end sub delete_action
3884 =head3 C<cmd_b> (command)
3886 Set breakpoints. Since breakpoints can be set in so many places, in so many
3887 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
3888 we try to parse the command type, and then shuttle it off to an appropriate
3889 subroutine to actually do the work of setting the breakpoint in the right
3896 my $line = shift; # [.|line] [cond]
3899 # Make . the current line number if it's there..
3900 $line =~ s/^\./$dbline/;
3902 # No line number, no condition. Simple break on current line.
3903 if ( $line =~ /^\s*$/ ) {
3904 &cmd_b_line( $dbline, 1 );
3907 # Break on load for a file.
3908 elsif ( $line =~ /^load\b\s*(.*)/ ) {
3914 # b compile|postpone <some sub> [<condition>]
3915 # The interpreter actually traps this one for us; we just put the
3916 # necessary condition in the %postponed hash.
3917 elsif ( $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
3919 # Capture the condition if there is one. Make it true if none.
3920 my $cond = length $3 ? $3 : '1';
3922 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
3923 # if it was 'compile'.
3924 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
3926 # De-Perl4-ify the name - ' separators to ::.
3927 $subname =~ s/\'/::/g;
3929 # Qualify it into the current package unless it's already qualified.
3930 $subname = "${'package'}::" . $subname unless $subname =~ /::/;
3932 # Add main if it starts with ::.
3933 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
3935 # Save the break type for this sub.
3936 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
3937 } ## end elsif ($line =~ ...
3939 # b <sub name> [<condition>]
3940 elsif ( $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
3944 $cond = length $2 ? $2 : '1';
3945 &cmd_b_sub( $subname, $cond );
3948 # b <line> [<condition>].
3949 elsif ( $line =~ /^(\d*)\s*(.*)/ ) {
3951 # Capture the line. If none, it's the current line.
3952 $line = $1 || $dbline;
3954 # If there's no condition, make it '1'.
3955 $cond = length $2 ? $2 : '1';
3958 &cmd_b_line( $line, $cond );
3961 # Line didn't make sense.
3963 print "confused by line($line)?\n";
3967 =head3 C<break_on_load> (API)
3969 We want to break when this file is loaded. Mark this file in the
3970 C<%break_on_load> hash, and note that it has a breakpoint in
3971 C<%had_breakpoints>.
3977 $break_on_load{$file} = 1;
3978 $had_breakpoints{$file} |= 1;
3981 =head3 C<report_break_on_load> (API)
3983 Gives us an array of filenames that are set to break on load. Note that
3984 only files with break-on-load are in here, so simply showing the keys
3989 sub report_break_on_load {
3990 sort keys %break_on_load;
3993 =head3 C<cmd_b_load> (command)
3995 We take the file passed in and try to find it in C<%INC> (which maps modules
3996 to files they came from). We mark those files for break-on-load via
3997 C<break_on_load> and then report that it was done.
4005 # This is a block because that way we can use a redo inside it
4006 # even without there being any looping structure at all outside it.
4009 # Save short name and full path if found.
4011 push @files, $::INC{$file} if $::INC{$file};
4013 # Tack on .pm and do it again unless there was a '.' in the name
4015 $file .= '.pm', redo unless $file =~ /\./;
4018 # Do the real work here.
4019 break_on_load($_) for @files;
4021 # All the files that have break-on-load breakpoints.
4022 @files = report_break_on_load;
4024 # Normalize for the purposes of our printing this.
4027 print $OUT "Will stop on load of `@files'.\n";
4028 } ## end sub cmd_b_load
4030 =head3 C<$filename_error> (API package global)
4032 Several of the functions we need to implement in the API need to work both
4033 on the current file and on other files. We don't want to duplicate code, so
4034 C<$filename_error> is used to contain the name of the file that's being
4035 worked on (if it's not the current one).
4037 We can now build functions in pairs: the basic function works on the current
4038 file, and uses C<$filename_error> as part of its error message. Since this is
4039 initialized to C<''>, no filename will appear when we are working on the
4042 The second function is a wrapper which does the following:
4046 =item * Localizes C<$filename_error> and sets it to the name of the file to be processed.
4048 =item * Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4050 =item * Calls the first function.
4052 The first function works on the "current" (i.e., the one we changed to) file,
4053 and prints C<$filename_error> in the error message (the name of the other file)
4054 if it needs to. When the functions return, C<*dbline> is restored to point to the actual current file (the one we're executing in) and C<$filename_error> is
4055 restored to C<''>. This restores everything to the way it was before the
4056 second function was called at all.
4058 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4065 $filename_error = '';
4067 =head3 breakable_line($from, $to) (API)
4069 The subroutine decides whether or not a line in the current file is breakable.
4070 It walks through C<@dbline> within the range of lines specified, looking for
4071 the first line that is breakable.
4073 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4074 first line I<after> C<$to> that's breakable, if there is one.
4076 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4077 first line I<before> C<$to> that's breakable, if there is one.
4081 sub breakable_line {
4083 my ( $from, $to ) = @_;
4085 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4088 # If there are at least 2 arguments, we're trying to search a range.
4091 # $delta is positive for a forward search, negative for a backward one.
4092 my $delta = $from < $to ? +1 : -1;
4094 # Keep us from running off the ends of the file.
4095 my $limit = $delta > 0 ? $#dbline : 1;
4097 # Clever test. If you're a mathematician, it's obvious why this
4098 # test works. If not:
4099 # If $delta is positive (going forward), $limit will be $#dbline.
4100 # If $to is less than $limit, ($limit - $to) will be positive, times
4101 # $delta of 1 (positive), so the result is > 0 and we should use $to
4102 # as the stopping point.
4104 # If $to is greater than $limit, ($limit - $to) is negative,
4105 # times $delta of 1 (positive), so the result is < 0 and we should
4106 # use $limit ($#dbline) as the stopping point.
4108 # If $delta is negative (going backward), $limit will be 1.
4109 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4110 # (negative) so the result is > 0, and we use $to as the stopping
4113 # If $to is less than zero, ($limit - $to) will be positive,
4114 # times $delta of -1 (negative), so the result is not > 0, and
4115 # we use $limit (1) as the stopping point.
4117 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4118 # (negative), still giving zero; the result is not > 0, and
4119 # we use $limit (1) as the stopping point.
4121 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4122 # (negative), giving a positive (>0) value, so we'll set $limit to
4125 $limit = $to if ( $limit - $to ) * $delta > 0;
4127 # The real search loop.
4128 # $i starts at $from (the point we want to start searching from).
4129 # We move through @dbline in the appropriate direction (determined
4130 # by $delta: either -1 (back) or +1 (ahead).
4131 # We stay in as long as we haven't hit an executable line
4132 # ($dbline[$i] == 0 means not executable) and we haven't reached
4133 # the limit yet (test similar to the above).
4134 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4136 } ## end if (@_ >= 2)
4138 # If $i points to a line that is executable, return that.
4139 return $i unless $dbline[$i] == 0;
4141 # Format the message and print it: no breakable lines in range.
4142 my ( $pl, $upto ) = ( '', '' );
4143 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4145 # If there's a filename in filename_error, we'll see it.
4147 die "Line$pl $from$upto$filename_error not breakable\n";
4148 } ## end sub breakable_line
4150 =head3 breakable_line_in_filename($file, $from, $to) (API)
4152 Like C<breakable_line>, but look in another file.
4156 sub breakable_line_in_filename {
4158 # Capture the file name.
4161 # Swap the magic line array over there temporarily.
4162 local *dbline = $main::{ '_<' . $f };
4164 # If there's an error, it's in this other file.
4165 local $filename_error = " of `$f'";
4167 # Find the breakable line.
4170 # *dbline and $filename_error get restored when this block ends.
4172 } ## end sub breakable_line_in_filename
4174 =head3 break_on_line(lineno, [condition]) (API)
4176 Adds a breakpoint with the specified condition (or 1 if no condition was
4177 specified) to the specified line. Dies if it can't.
4182 my ( $i, $cond ) = @_;
4184 # Always true if no condition supplied.
4185 $cond = 1 unless @_ >= 2;
4191 # Woops, not a breakable line. $filename_error allows us to say
4192 # if it was in a different file.
4193 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4195 # Mark this file as having breakpoints in it.
4196 $had_breakpoints{$filename} |= 1;
4198 # If there is an action or condition here already ...
4199 if ( $dbline{$i} ) {
4201 # ... swap this condition for the existing one.
4202 $dbline{$i} =~ s/^[^\0]*/$cond/;
4206 # Nothing here - just add the condition.
4207 $dbline{$i} = $cond;
4209 } ## end sub break_on_line
4211 =head3 cmd_b_line(line, [condition]) (command)
4213 Wrapper for C<break_on_line>. Prints the failure message if it
4219 eval { break_on_line(@_); 1 } or do {
4221 print $OUT $@ and return;
4223 } ## end sub cmd_b_line
4225 =head3 break_on_filename_line(file, line, [condition]) (API)
4227 Switches to the file specified and then calls C<break_on_line> to set
4232 sub break_on_filename_line {
4233 my ( $f, $i, $cond ) = @_;
4235 # Always true if condition left off.
4236 $cond = 1 unless @_ >= 3;
4238 # Switch the magical hash temporarily.
4239 local *dbline = $main::{ '_<' . $f };
4241 # Localize the variables that break_on_line uses to make its message.
4242 local $filename_error = " of `$f'";
4243 local $filename = $f;
4245 # Add the breakpoint.
4246 break_on_line( $i, $cond );
4247 } ## end sub break_on_filename_line
4249 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4251 Switch to another file, search the range of lines specified for an
4252 executable one, and put a breakpoint on the first one you find.
4256 sub break_on_filename_line_range {
4257 my ( $f, $from, $to, $cond ) = @_;
4259 # Find a breakable line if there is one.
4260 my $i = breakable_line_in_filename( $f, $from, $to );
4262 # Always true if missing.
4263 $cond = 1 unless @_ >= 3;
4265 # Add the breakpoint.
4266 break_on_filename_line( $f, $i, $cond );
4267 } ## end sub break_on_filename_line_range
4269 =head3 subroutine_filename_lines(subname, [condition]) (API)
4271 Search for a subroutine within a given file. The condition is ignored.
4272 Uses C<find_sub> to locate the desired subroutine.
4276 sub subroutine_filename_lines {
4277 my ( $subname, $cond ) = @_;
4279 # Returned value from find_sub() is fullpathname:startline-endline.
4280 # The match creates the list (fullpathname, start, end). Falling off
4281 # the end of the subroutine returns this implicitly.
4282 find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/;
4283 } ## end sub subroutine_filename_lines
4285 =head3 break_subroutine(subname) (API)
4287 Places a break on the first line possible in the specified subroutine. Uses
4288 C<subroutine_filename_lines> to find the subroutine, and
4289 C<break_on_filename_line_range> to place the break.
4293 sub break_subroutine {
4294 my $subname = shift;
4296 # Get filename, start, and end.
4297 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
4298 or die "Subroutine $subname not found.\n";
4300 # Null condition changes to '1' (always true).
4301 $cond = 1 unless @_ >= 2;
4303 # Put a break the first place possible in the range of lines
4304 # that make up this subroutine.
4305 break_on_filename_line_range( $file, $s, $e, @_ );
4306 } ## end sub break_subroutine
4308 =head3 cmd_b_sub(subname, [condition]) (command)
4310 We take the incoming subroutine name and fully-qualify it as best we can.
4314 =item 1. If it's already fully-qualified, leave it alone.
4316 =item 2. Try putting it in the current package.
4318 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
4320 =item 4. If it starts with '::', put it in 'main::'.
4324 After all this cleanup, we call C<break_subroutine> to try to set the
4330 my ( $subname, $cond ) = @_;
4332 # Add always-true condition if we have none.
4333 $cond = 1 unless @_ >= 2;
4335 # If the subname isn't a code reference, qualify it so that
4336 # break_subroutine() will work right.
4337 unless ( ref $subname eq 'CODE' ) {
4340 $subname =~ s/\'/::/g;
4343 # Put it in this package unless it's already qualified.
4344 $subname = "${'package'}::" . $subname
4345 unless $subname =~ /::/;
4347 # Requalify it into CORE::GLOBAL if qualifying it into this
4348 # package resulted in its not being defined, but only do so
4349 # if it really is in CORE::GLOBAL.
4350 $subname = "CORE::GLOBAL::$s"
4351 if not defined &$subname
4353 and defined &{"CORE::GLOBAL::$s"};
4355 # Put it in package 'main' if it has a leading ::.
4356 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4358 } ## end unless (ref $subname eq 'CODE')
4360 # Try to set the breakpoint.
4361 eval { break_subroutine( $subname, $cond ); 1 } or do {
4363 print $OUT $@ and return;
4365 } ## end sub cmd_b_sub
4367 =head3 C<cmd_B> - delete breakpoint(s) (command)
4369 The command mostly parses the command line and tries to turn the argument
4370 into a line spec. If it can't, it uses the current line. It then calls
4371 C<delete_breakpoint> to actually do the work.
4373 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
4374 thereby deleting all the breakpoints.
4381 # No line spec? Use dbline.
4382 # If there is one, use it if it's non-zero, or wipe it out if it is.
4383 my $line = ( $_[0] =~ /^\./ ) ? $dbline : shift || '';
4386 # If the line was dot, make the line the current one.
4387 $line =~ s/^\./$dbline/;
4389 # If it's * we're deleting all the breakpoints.
4390 if ( $line eq '*' ) {
4391 eval { &delete_breakpoint(); 1 } or print $OUT $@ and return;
4394 # If there is a line spec, delete the breakpoint on that line.
4395 elsif ( $line =~ /^(\S.*)/ ) {
4396 eval { &delete_breakpoint( $line || $dbline ); 1 } or do {
4398 print $OUT $@ and return;
4400 } ## end elsif ($line =~ /^(\S.*)/)
4405 "Deleting a breakpoint requires a line number, or '*' for all\n"
4410 =head3 delete_breakpoint([line]) (API)
4412 This actually does the work of deleting either a single breakpoint, or all
4415 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
4416 just drop out with a message saying so. If it is, we remove the condition
4417 part of the 'condition\0action' that says there's a breakpoint here. If,
4418 after we've done that, there's nothing left, we delete the corresponding
4419 line in C<%dbline> to signal that no action needs to be taken for this line.
4421 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
4422 which lists all currently-loaded files which have breakpoints. We then look
4423 at each line in each of these files, temporarily switching the C<%dbline>
4424 and C<@dbline> structures to point to the files in question, and do what
4425 we did in the single line case: delete the condition in C<@dbline>, and
4426 delete the key in C<%dbline> if nothing's left.
4428 We then wholesale delete C<%postponed>, C<%postponed_file>, and
4429 C<%break_on_load>, because these structures contain breakpoints for files
4430 and code that haven't been loaded yet. We can just kill these off because there
4431 are no magical debugger structures associated with them.
4435 sub delete_breakpoint {
4438 # If we got a line, delete just that one.
4439 if ( defined($i) ) {
4441 # Woops. This line wasn't breakable at all.
4442 die "Line $i not breakable.\n" if $dbline[$i] == 0;
4444 # Kill the condition, but leave any action.
4445 $dbline{$i} =~ s/^[^\0]*//;
4447 # Remove the entry entirely if there's no action left.
4448 delete $dbline{$i} if $dbline{$i} eq '';
4451 # No line; delete them all.
4453 print $OUT "Deleting all breakpoints...\n";
4455 # %had_breakpoints lists every file that had at least one
4457 for my $file ( keys %had_breakpoints ) {
4459 # Switch to the desired file temporarily.
4460 local *dbline = $main::{ '_<' . $file };
4465 # For all lines in this file ...
4466 for ( $i = 1 ; $i <= $max ; $i++ ) {
4468 # If there's a breakpoint or action on this line ...
4469 if ( defined $dbline{$i} ) {
4471 # ... remove the breakpoint.
4472 $dbline{$i} =~ s/^[^\0]+//;
4473 if ( $dbline{$i} =~ s/^\0?$// ) {
4475 # Remove the entry altogether if no action is there.
4478 } ## end if (defined $dbline{$i...
4479 } ## end for ($i = 1 ; $i <= $max...
4481 # If, after we turn off the "there were breakpoints in this file"
4482 # bit, the entry in %had_breakpoints for this file is zero,
4483 # we should remove this file from the hash.
4484 if ( not $had_breakpoints{$file} &= ~1 ) {
4485 delete $had_breakpoints{$file};
4487 } ## end for my $file (keys %had_breakpoints)
4489 # Kill off all the other breakpoints that are waiting for files that
4490 # haven't been loaded yet.
4492 undef %postponed_file;
4493 undef %break_on_load;
4494 } ## end else [ if (defined($i))
4495 } ## end sub delete_breakpoint
4497 =head3 cmd_stop (command)
4499 This is meant to be part of the new command API, but it isn't called or used
4500 anywhere else in the debugger. XXX It is probably meant for use in development
4505 sub cmd_stop { # As on ^C, but not signal-safy.
4509 =head3 C<cmd_h> - help command (command)
4511 Does the work of either
4515 =item * Showing all the debugger help
4517 =item * Showing help for a specific command
4526 # If we have no operand, assume null.
4527 my $line = shift || '';
4529 # 'h h'. Print the long-format help.
4530 if ( $line =~ /^h\s*/ ) {
4534 # 'h <something>'. Search for the command and print only its help.
4535 elsif ( $line =~ /^(\S.*)$/ ) {
4537 # support long commands; otherwise bogus errors
4538 # happen when you ask for h on <CR> for example
4539 my $asked = $1; # the command requested
4540 # (for proper error message)
4542 my $qasked = quotemeta($asked); # for searching; we don't
4543 # want to use it as a pattern.
4544 # XXX: finds CR but not <CR>
4546 # Search the help string for the command.
4548 $help =~ /^ # Start of a line
4550 (?:[IB]<) # Optional markup
4551 $qasked # The requested command
4556 # It's there; pull it out and print it.
4560 (?:[IB]<) # Optional markup
4561 $qasked # The command
4562 ([\s\S]*?) # Description line(s)
4563 \n) # End of last description line
4564 (?!\s) # Next line not starting with
4573 # Not found; not a debugger command.
4575 print_help("B<$asked> is not a debugger command.\n");
4577 } ## end elsif ($line =~ /^(\S.*)$/)
4579 # 'h' - print the summary help.
4581 print_help($summary);
4585 =head3 C<cmd_i> - inheritance display
4587 Display the (nested) parentage of the module or object given.
4594 eval { require Class::ISA };
4596 &warn( $@ =~ /locate/
4597 ? "Class::ISA module not found - please install\n"
4602 foreach my $isa ( split( /\s+/, $line ) ) {
4608 map { # snaffled unceremoniously from Class::ISA
4611 defined( ${"$_\::VERSION"} )
4612 ? ' ' . ${"$_\::VERSION"}
4614 } Class::ISA::self_and_super_path(ref($isa) || $isa)
4621 =head3 C<cmd_l> - list lines (command)
4623 Most of the command is taken up with transforming all the different line
4624 specification syntaxes into 'start-stop'. After that is done, the command
4625 runs a loop over C<@dbline> for the specified range of lines. It handles
4626 the printing of each line and any markers (C<==E<gt>> for current line,
4627 C<b> for break on this line, C<a> for action on this line, C<:> for this
4630 We save the last line listed in the C<$start> global for further listing
4636 my $current_line = $line;
4640 # If this is '-something', delete any spaces after the dash.
4641 $line =~ s/^-\s*$/-/;
4643 # If the line is '$something', assume this is a scalar containing a
4645 if ( $line =~ /^(\$.*)/s ) {
4647 # Set up for DB::eval() - evaluate in *user* context.
4652 # Ooops. Bad scalar.
4653 print( $OUT "Error: $@\n" ), next CMD if $@;
4655 # Good scalar. If it's a reference, find what it points to.
4657 print( $OUT "Interpreted as: $1 $s\n" );
4660 # Call self recursively to really do the command.
4662 } ## end if ($line =~ /^(\$.*)/s)
4664 # l name. Try to find a sub by that name.
4665 elsif ( $line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s ) {
4666 my $s = $subname = $1;
4669 $subname =~ s/\'/::/;
4671 # Put it in this package unless it starts with ::.
4672 $subname = $package . "::" . $subname unless $subname =~ /::/;
4674 # Put it in CORE::GLOBAL if t doesn't start with :: and
4675 # it doesn't live in this package and it lives in CORE::GLOBAL.
4676 $subname = "CORE::GLOBAL::$s"
4677 if not defined &$subname
4679 and defined &{"CORE::GLOBAL::$s"};
4681 # Put leading '::' names into 'main::'.
4682 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4684 # Get name:start-stop from find_sub, and break this up at
4686 @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
4688 # Pull off start-stop.
4689 $subrange = pop @pieces;
4691 # If the name contained colons, the split broke it up.
4692 # Put it back together.
4693 $file = join( ':', @pieces );
4695 # If we're not in that file, switch over to it.
4696 if ( $file ne $filename ) {
4697 print $OUT "Switching to file '$file'.\n"
4698 unless $slave_editor;
4700 # Switch debugger's magic structures.
4701 *dbline = $main::{ '_<' . $file };
4704 } ## end if ($file ne $filename)
4706 # Subrange is 'start-stop'. If this is less than a window full,
4707 # swap it to 'start+', which will list a window from the start point.
4709 if ( eval($subrange) < -$window ) {
4710 $subrange =~ s/-.*/+/;
4713 # Call self recursively to list the range.
4715 &cmd_l( 'l', $subrange );
4716 } ## end if ($subrange)
4720 print $OUT "Subroutine $subname not found.\n";
4722 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s)
4725 elsif ( $line =~ /^\s*$/ ) {
4727 # Compute new range to list.
4728 $incr = $window - 1;
4729 $line = $start . '-' . ( $start + $incr );
4732 &cmd_l( 'l', $line );
4735 # l [start]+number_of_lines
4736 elsif ( $line =~ /^(\d*)\+(\d*)$/ ) {
4738 # Don't reset start for 'l +nnn'.
4741 # Increment for list. Use window size if not specified.
4742 # (Allows 'l +' to work.)
4744 $incr = $window - 1 unless $incr;
4746 # Create a line range we'll understand, and recurse to do it.
4747 $line = $start . '-' . ( $start + $incr );
4748 &cmd_l( 'l', $line );
4749 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/)
4751 # l start-stop or l start,stop
4752 elsif ( $line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/ ) {
4754 # Determine end point; use end of file if not specified.
4755 $end = ( !defined $2 ) ? $max : ( $4 ? $4 : $2 );
4757 # Go on to the end, and then stop.
4758 $end = $max if $end > $max;
4760 # Determine start line.
4762 $i = $line if $i eq '.';
4766 # If we're running under a slave editor, force it to show the lines.
4767 if ($slave_editor) {
4768 print $OUT "\032\032$filename:$i:0\n";
4772 # We're doing it ourselves. We want to show the line and special
4774 # - the current line in execution
4775 # - whether a line is breakable or not
4776 # - whether a line has a break or not
4777 # - whether a line has an action or not
4779 for ( ; $i <= $end ; $i++ ) {
4781 # Check for breakpoints and actions.
4782 my ( $stop, $action );
4783 ( $stop, $action ) = split( /\0/, $dbline{$i} )
4786 # ==> if this is the current line in execution,
4787 # : if it's breakable.
4789 ( $i == $current_line and $filename eq $filename_ini )
4791 : ( $dbline[$i] + 0 ? ':' : ' ' );
4793 # Add break and action indicators.
4794 $arrow .= 'b' if $stop;
4795 $arrow .= 'a' if $action;
4798 print $OUT "$i$arrow\t", $dbline[$i];
4800 # Move on to the next line. Drop out on an interrupt.
4801 $i++, last if $signal;
4802 } ## end for (; $i <= $end ; $i++)
4804 # Line the prompt up; print a newline if the last line listed
4805 # didn't have a newline.
4806 print $OUT "\n" unless $dbline[ $i - 1 ] =~ /\n$/;
4807 } ## end else [ if ($slave_editor)
4809 # Save the point we last listed to in case another relative 'l'
4810 # command is desired. Don't let it run off the end.
4812 $start = $max if $start > $max;
4813 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/)
4816 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
4818 To list breakpoints, the command has to look determine where all of them are
4819 first. It starts a C<%had_breakpoints>, which tells us what all files have
4820 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
4821 magic source and breakpoint data structures) to the file, and then look
4822 through C<%dbline> for lines with breakpoints and/or actions, listing them
4823 out. We look through C<%postponed> not-yet-compiled subroutines that have
4824 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
4825 that have breakpoints.
4827 Watchpoints are simpler: we just list the entries in C<@to_watch>.
4834 # If no argument, list everything. Pre-5.8.0 version always lists
4836 my $arg = shift || 'abw';
4837 $arg = 'abw' unless $CommandSet eq '580'; # sigh...
4839 # See what is wanted.
4840 my $action_wanted = ( $arg =~ /a/ ) ? 1 : 0;
4841 my $break_wanted = ( $arg =~ /b/ ) ? 1 : 0;
4842 my $watch_wanted = ( $arg =~ /w/ ) ? 1 : 0;
4844 # Breaks and actions are found together, so we look in the same place
4846 if ( $break_wanted or $action_wanted ) {
4848 # Look in all the files with breakpoints...
4849 for my $file ( keys %had_breakpoints ) {
4851 # Temporary switch to this file.
4852 local *dbline = $main::{ '_<' . $file };
4854 # Set up to look through the whole file.
4856 my $was; # Flag: did we print something
4859 # For each line in the file ...
4860 for ( $i = 1 ; $i <= $max ; $i++ ) {
4862 # We've got something on this line.
4863 if ( defined $dbline{$i} ) {
4865 # Print the header if we haven't.
4866 print $OUT "$file:\n" unless $was++;
4869 print $OUT " $i:\t", $dbline[$i];
4871 # Pull out the condition and the action.
4872 ( $stop, $action ) = split( /\0/, $dbline{$i} );
4874 # Print the break if there is one and it's wanted.
4875 print $OUT " break if (", $stop, ")\n"
4879 # Print the action if there is one and it's wanted.
4880 print $OUT " action: ", $action, "\n"
4884 # Quit if the user hit interrupt.
4886 } ## end if (defined $dbline{$i...
4887 } ## end for ($i = 1 ; $i <= $max...
4888 } ## end for my $file (keys %had_breakpoints)
4889 } ## end if ($break_wanted or $action_wanted)
4891 # Look for breaks in not-yet-compiled subs:
4892 if ( %postponed and $break_wanted ) {
4893 print $OUT "Postponed breakpoints in subroutines:\n";
4895 for $subname ( keys %postponed ) {
4896 print $OUT " $subname\t$postponed{$subname}\n";
4899 } ## end if (%postponed and $break_wanted)
4901 # Find files that have not-yet-loaded breaks:
4902 my @have = map { # Combined keys
4903 keys %{ $postponed_file{$_} }
4904 } keys %postponed_file;
4906 # If there are any, list them.
4907 if ( @have and ( $break_wanted or $action_wanted ) ) {
4908 print $OUT "Postponed breakpoints in files:\n";
4909 my ( $file, $line );
4911 for $file ( keys %postponed_file ) {
4912 my $db = $postponed_file{$file};
4913 print $OUT " $file:\n";
4914 for $line ( sort { $a <=> $b } keys %$db ) {
4915 print $OUT " $line:\n";
4916 my ( $stop, $action ) = split( /\0/, $$db{$line} );
4917 print $OUT " break if (", $stop, ")\n"
4920 print $OUT " action: ", $action, "\n"
4924 } ## end for $line (sort { $a <=>...
4926 } ## end for $file (keys %postponed_file)
4927 } ## end if (@have and ($break_wanted...
4928 if ( %break_on_load and $break_wanted ) {
4929 print $OUT "Breakpoints on load:\n";
4931 for $file ( keys %break_on_load ) {
4932 print $OUT " $file\n";
4935 } ## end if (%break_on_load and...
4936 if ($watch_wanted) {
4938 print $OUT "Watch-expressions:\n" if @to_watch;
4939 for my $expr (@to_watch) {
4940 print $OUT " $expr\n";
4943 } ## end if ($trace & 2)
4944 } ## end if ($watch_wanted)
4947 =head3 C<cmd_M> - list modules (command)
4949 Just call C<list_modules>.
4957 =head3 C<cmd_o> - options (command)
4959 If this is just C<o> by itself, we list the current settings via
4960 C<dump_option>. If there's a nonblank value following it, we pass that on to
4961 C<parse_options> for processing.
4967 my $opt = shift || ''; # opt[=val]
4969 # Nonblank. Try to parse and process.
4970 if ( $opt =~ /^(\S.*)/ ) {
4974 # Blank. List the current option settings.
4982 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
4984 Advises the user that the O command has been renamed.
4989 print $OUT "The old O command is now the o command.\n"; # hint
4990 print $OUT "Use 'h' to get current command help synopsis or\n"; #
4991 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
4994 =head3 C<cmd_v> - view window (command)
4996 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
4997 move back a few lines to list the selected line in context. Uses C<cmd_l>
4998 to do the actual listing after figuring out the range of line to request.
5006 # Extract the line to list around. (Astute readers will have noted that
5007 # this pattern will match whether or not a numeric line is specified,
5008 # which means that we'll always enter this loop (though a non-numeric
5009 # argument results in no action at all)).
5010 if ( $line =~ /^(\d*)$/ ) {
5012 # Total number of lines to list (a windowful).
5013 $incr = $window - 1;
5015 # Set the start to the argument given (if there was one).
5018 # Back up by the context amount.
5021 # Put together a linespec that cmd_l will like.
5022 $line = $start . '-' . ( $start + $incr );
5025 &cmd_l( 'l', $line );
5026 } ## end if ($line =~ /^(\d*)$/)
5029 =head3 C<cmd_w> - add a watch expression (command)
5031 The 5.8 version of this command adds a watch expression if one is specified;
5032 it does nothing if entered with no operands.
5034 We extract the expression, save it, evaluate it in the user's context, and
5035 save the value. We'll re-evaluate it each time the debugger passes a line,
5036 and will stop (see the code at the top of the command loop) if the value
5037 of any of the expressions changes.
5044 # Null expression if no arguments.
5045 my $expr = shift || '';
5047 # If expression is not null ...
5048 if ( $expr =~ /^(\S.*)/ ) {
5051 push @to_watch, $expr;
5053 # Parameterize DB::eval and call it to get the expression's value
5054 # in the user's context. This version can handle expressions which
5055 # return a list value.
5057 my ($val) = join( ' ', &eval );
5058 $val = ( defined $val ) ? "'$val'" : 'undef';
5060 # Save the current value of the expression.
5061 push @old_watch, $val;
5063 # We are now watching expressions.
5065 } ## end if ($expr =~ /^(\S.*)/)
5067 # You have to give one to get one.
5069 print $OUT "Adding a watch-expression requires an expression\n"; # hint
5073 =head3 C<cmd_W> - delete watch expressions (command)
5075 This command accepts either a watch expression to be removed from the list
5076 of watch expressions, or C<*> to delete them all.
5078 If C<*> is specified, we simply empty the watch expression list and the
5079 watch expression value list. We also turn off the bit that says we've got
5082 If an expression (or partial expression) is specified, we pattern-match
5083 through the expressions and remove the ones that match. We also discard
5084 the corresponding values. If no watch expressions are left, we turn off
5085 the 'watching expressions' bit.
5091 my $expr = shift || '';
5094 if ( $expr eq '*' ) {
5099 print $OUT "Deleting all watch expressions ...\n";
5102 @to_watch = @old_watch = ();
5105 # Delete one of them.
5106 elsif ( $expr =~ /^(\S.*)/ ) {
5108 # Where we are in the list.
5111 # For each expression ...
5112 foreach (@to_watch) {
5113 my $val = $to_watch[$i_cnt];
5115 # Does this one match the command argument?
5116 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
5117 # Yes. Turn it off, and its value too.
5118 splice( @to_watch, $i_cnt, 1 );
5119 splice( @old_watch, $i_cnt, 1 );
5122 } ## end foreach (@to_watch)
5124 # We don't bother to turn watching off because
5125 # a) we don't want to stop calling watchfunction() it it exists
5126 # b) foreach over a null list doesn't do anything anyway
5128 } ## end elsif ($expr =~ /^(\S.*)/)
5130 # No command arguments entered.
5133 "Deleting a watch-expression requires an expression, or '*' for all\n"
5138 ### END of the API section
5140 =head1 SUPPORT ROUTINES
5142 These are general support routines that are used in a number of places
5143 throughout the debugger.
5147 Something to do with assertions
5152 unless ($ini_assertion) {
5153 print $OUT "Assertions not supported in this Perl interpreter\n";
5155 if ( $cmd =~ /^.\b\s*([+-]?)\s*(~?)\s*(\w+(\s*\|\s*\w+)*)\s*$/ ) {
5156 my ( $how, $neg, $flags ) = ( $1, $2, $3 );
5157 my $acu = parse_DollarCaretP_flags($flags);
5158 if ( defined $acu ) {
5159 $acu = ~$acu if $neg;
5160 if ( $how eq '+' ) { $^P |= $acu }
5161 elsif ( $how eq '-' ) { $^P &= ~$acu }
5165 # else { print $OUT "undefined acu\n" }
5167 my $expanded = expand_DollarCaretP_flags($^P);
5168 print $OUT "Internal Perl debugger flags:\n\$^P=$expanded\n";
5175 save() saves the user's versions of globals that would mess us up in C<@saved>,
5176 and installs the versions we like better.
5182 # Save eval failure, command failure, extended OS error, output field
5183 # separator, input record separator, output record separator and
5184 # the warning setting.
5185 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
5187 $, = ""; # output field separator is null string
5188 $/ = "\n"; # input record separator is newline
5189 $\ = ""; # output record separator is null string
5190 $^W = 0; # warnings are off
5193 =head2 C<print_lineinfo> - show where we are now
5195 print_lineinfo prints whatever it is that it is handed; it prints it to the
5196 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
5197 us to feed line information to a slave editor without messing up the
5202 sub print_lineinfo {
5204 # Make the terminal sensible if we're not the primary debugger.
5205 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
5209 } ## end sub print_lineinfo
5211 =head2 C<postponed_sub>
5213 Handles setting postponed breakpoints in subroutines once they're compiled.
5214 For breakpoints, we use C<DB::find_sub> to locate the source file and line
5215 range for the subroutine, then mark the file as having a breakpoint,
5216 temporarily switch the C<*dbline> glob over to the source file, and then
5217 search the given range of lines to find a breakable line. If we find one,
5218 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
5222 # The following takes its argument via $evalarg to preserve current @_
5226 # Get the subroutine name.
5227 my $subname = shift;
5229 # If this is a 'break +<n> if <condition>' ...
5230 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
5232 # If there's no offset, use '+0'.
5233 my $offset = $1 || 0;
5235 # find_sub's value is 'fullpath-filename:start-stop'. It's
5236 # possible that the filename might have colons in it too.
5237 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
5240 # We got the start line. Add the offset '+<n>' from
5241 # $postponed{subname}.
5244 # Switch to the file this sub is in, temporarily.
5245 local *dbline = $main::{ '_<' . $file };
5247 # No warnings, please.
5248 local $^W = 0; # != 0 is magical below
5250 # This file's got a breakpoint in it.
5251 $had_breakpoints{$file} |= 1;
5253 # Last line in file.
5256 # Search forward until we hit a breakable line or get to
5257 # the end of the file.
5258 ++$i until $dbline[$i] != 0 or $i >= $max;
5260 # Copy the breakpoint in and delete it from %postponed.
5261 $dbline{$i} = delete $postponed{$subname};
5264 # find_sub didn't find the sub.
5267 print $OUT "Subroutine $subname not found.\n";
5270 } ## end if ($postponed{$subname...
5271 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
5273 #print $OUT "In postponed_sub for `$subname'.\n";
5274 } ## end sub postponed_sub
5278 Called after each required file is compiled, but before it is executed;
5279 also called if the name of a just-compiled subroutine is a key of
5280 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
5281 etc.) into the just-compiled code.
5283 If this is a C<require>'d file, the incoming parameter is the glob
5284 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
5286 If it's a subroutine, the incoming parameter is the subroutine name.
5292 # If there's a break, process it.
5293 if ($ImmediateStop) {
5295 # Right, we've stopped. Turn it off.
5298 # Enter the command loop when DB::DB gets called.
5302 # If this is a subroutine, let postponed_sub() deal with it.
5303 return &postponed_sub unless ref \$_[0] eq 'GLOB';
5305 # Not a subroutine. Deal with the file.
5306 local *dbline = shift;
5307 my $filename = $dbline;
5308 $filename =~ s/^_<//;
5310 $signal = 1, print $OUT "'$filename' loaded...\n"
5311 if $break_on_load{$filename};
5312 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
5314 # Do we have any breakpoints to put in this file?
5315 return unless $postponed_file{$filename};
5317 # Yes. Mark this file as having breakpoints.
5318 $had_breakpoints{$filename} |= 1;
5320 # "Cannot be done: unsufficient magic" - we can't just put the
5321 # breakpoints saved in %postponed_file into %dbline by assigning
5322 # the whole hash; we have to do it one item at a time for the
5323 # breakpoints to be set properly.
5324 #%dbline = %{$postponed_file{$filename}};
5326 # Set the breakpoints, one at a time.
5329 for $key ( keys %{ $postponed_file{$filename} } ) {
5331 # Stash the saved breakpoint into the current file's magic line array.
5332 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
5335 # This file's been compiled; discard the stored breakpoints.
5336 delete $postponed_file{$filename};
5338 } ## end sub postponed
5342 C<dumpit> is the debugger's wrapper around dumpvar.pl.
5344 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
5345 a reference to a variable (the thing to be dumped) as its input.
5347 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
5348 the currently-selected filehandle, thank you very much). The current
5349 values of the package globals C<$single> and C<$trace> are backed up in
5350 lexicals, and they are turned off (this keeps the debugger from trying
5351 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
5352 preserve its current value and it is set to zero to prevent entry/exit
5353 messages from printing, and C<$doret> is localized as well and set to -2 to
5354 prevent return values from being shown.
5356 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
5357 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
5358 installed version in @INC, yours will be used instead. Possible security
5361 It then checks to see if the subroutine C<main::dumpValue> is now defined
5362 (it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
5363 localizes the globals necessary for things to be sane when C<main::dumpValue()>
5364 is called, and picks up the variable to be dumped from the parameter list.
5366 It checks the package global C<%options> to see if there's a C<dumpDepth>
5367 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
5368 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
5369 structure: -1 means dump everything.
5371 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
5374 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
5375 and we then return to the caller.
5381 # Save the current output filehandle and switch to the one
5382 # passed in as the first parameter.
5383 local ($savout) = select(shift);
5385 # Save current settings of $single and $trace, and then turn them off.
5386 my $osingle = $single;
5387 my $otrace = $trace;
5388 $single = $trace = 0;
5390 # XXX Okay, what do $frame and $doret do, again?
5394 # Load dumpvar.pl unless we've already got the sub we need from it.
5395 unless ( defined &main::dumpValue ) {
5399 # If the load succeeded (or we already had dumpvalue()), go ahead
5401 if ( defined &main::dumpValue ) {
5406 my $maxdepth = shift || $option{dumpDepth};
5407 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
5408 &main::dumpValue( $v, $maxdepth );
5409 } ## end if (defined &main::dumpValue)
5411 # Oops, couldn't load dumpvar.pl.
5414 print $OUT "dumpvar.pl not available.\n";
5417 # Reset $single and $trace to their old values.
5421 # Restore the old filehandle.
5425 =head2 C<print_trace>
5427 C<print_trace>'s job is to print a stack trace. It does this via the
5428 C<dump_trace> routine, which actually does all the ferreting-out of the
5429 stack trace data. C<print_trace> takes care of formatting it nicely and
5430 printing it to the proper filehandle.
5436 =item * The filehandle to print to.
5438 =item * How many frames to skip before starting trace.
5440 =item * How many frames to print.
5442 =item * A flag: if true, print a "short" trace without filenames, line numbers, or arguments
5446 The original comment below seems to be noting that the traceback may not be
5447 correct if this routine is called in a tied method.
5451 # Tied method do not create a context, so may get wrong message:
5457 # If this is going to a slave editor, but we're not the primary
5458 # debugger, reset it first.
5460 if $fh eq $LINEINFO # slave editor
5461 and $LINEINFO eq $OUT # normal output
5462 and $term_pid != $$; # not the primary
5464 # Collect the actual trace information to be formatted.
5465 # This is an array of hashes of subroutine call info.
5466 my @sub = dump_trace( $_[0] + 1, $_[1] );
5468 # Grab the "short report" flag from @_.
5469 my $short = $_[2]; # Print short report, next one for sub name
5471 # Run through the traceback info, format it, and print it.
5473 for ( $i = 0 ; $i <= $#sub ; $i++ ) {
5475 # Drop out if the user has lost interest and hit control-C.
5478 # Set the separator so arrys print nice.
5481 # Grab and stringify the arguments if they are there.
5483 defined $sub[$i]{args}
5484 ? "(@{ $sub[$i]{args} })"
5487 # Shorten them up if $maxtrace says they're too long.
5488 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
5489 if length $args > $maxtrace;
5491 # Get the file name.
5492 my $file = $sub[$i]{file};
5494 # Put in a filename header if short is off.
5495 $file = $file eq '-e' ? $file : "file `$file'" unless $short;
5497 # Get the actual sub's name, and shorten to $maxtrace's requirement.
5499 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
5501 # Short report uses trimmed file and sub names.
5503 my $sub = @_ >= 4 ? $_[3] : $s;
5504 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
5505 } ## end if ($short)
5507 # Non-short report includes full names.
5509 print $fh "$sub[$i]{context} = $s$args"
5510 . " called from $file"
5511 . " line $sub[$i]{line}\n";
5513 } ## end for ($i = 0 ; $i <= $#sub...
5514 } ## end sub print_trace
5516 =head2 dump_trace(skip[,count])
5518 Actually collect the traceback information available via C<caller()>. It does
5519 some filtering and cleanup of the data, but mostly it just collects it to
5520 make C<print_trace()>'s job easier.
5522 C<skip> defines the number of stack frames to be skipped, working backwards
5523 from the most current. C<count> determines the total number of frames to
5524 be returned; all of them (well, the first 10^9) are returned if C<count>
5527 This routine returns a list of hashes, from most-recent to least-recent
5528 stack frame. Each has the following keys and values:
5532 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
5534 =item * C<sub> - subroutine name, or C<eval> information
5536 =item * C<args> - undef, or a reference to an array of arguments
5538 =item * C<file> - the file in which this item was defined (if any)
5540 =item * C<line> - the line on which it was defined
5548 # How many levels to skip.
5551 # How many levels to show. (1e9 is a cheap way of saying "all of them";
5552 # it's unlikely that we'll have more than a billion stack frames. If you
5553 # do, you've got an awfully big machine...)
5554 my $count = shift || 1e9;
5556 # We increment skip because caller(1) is the first level *back* from
5557 # the current one. Add $skip to the count of frames so we have a
5558 # simple stop criterion, counting from $skip to $count+$skip.
5562 # These variables are used to capture output from caller();
5563 my ( $p, $file, $line, $sub, $h, $context );
5565 my ( $e, $r, @a, @sub, $args );
5567 # XXX Okay... why'd we do that?
5568 my $nothard = not $frame & 8;
5571 # Do not want to trace this.
5572 my $otrace = $trace;
5575 # Start out at the skip count.
5576 # If we haven't reached the number of frames requested, and caller() is
5577 # still returning something, stay in the loop. (If we pass the requested
5578 # number of stack frames, or we run out - caller() returns nothing - we
5580 # Up the stack frame index to go back one more level each time.
5584 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
5589 # Go through the arguments and save them for later.
5593 if ( not defined $arg ) { # undefined parameter
5597 elsif ( $nothard and tied $arg ) { # tied parameter
5600 elsif ( $nothard and $type = ref $arg ) { # reference
5601 push @a, "ref($type)";
5603 else { # can be stringified
5605 "$arg"; # Safe to stringify now - should not call f().
5607 # Backslash any single-quotes or backslashes.
5610 # Single-quote it unless it's a number or a colon-separated
5613 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
5615 # Turn high-bit characters into meta-whatever.
5616 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
5618 # Turn control characters into ^-whatever.
5619 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
5622 } ## end else [ if (not defined $arg)
5623 } ## end for $arg (@args)
5625 # If context is true, this is array (@)context.
5626 # If context is false, this is scalar ($) context.
5627 # If neither, context isn't defined. (This is apparently a 'can't
5629 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
5631 # if the sub has args ($h true), make an anonymous array of the
5633 $args = $h ? [@a] : undef;
5635 # remove trailing newline-whitespace-semicolon-end of line sequence
5636 # from the eval text, if any.
5637 $e =~ s/\n\s*\;\s*\Z// if $e;
5639 # Escape backslashed single-quotes again if necessary.
5640 $e =~ s/([\\\'])/\\$1/g if $e;
5642 # if the require flag is true, the eval text is from a require.
5644 $sub = "require '$e'";
5647 # if it's false, the eval text is really from an eval.
5648 elsif ( defined $r ) {
5652 # If the sub is '(eval)', this is a block eval, meaning we don't
5653 # know what the eval'ed text actually was.
5654 elsif ( $sub eq '(eval)' ) {
5655 $sub = "eval {...}";
5658 # Stick the collected information into @sub as an anonymous hash.
5662 context => $context,
5670 # Stop processing frames if the user hit control-C.
5672 } ## end for ($i = $skip ; $i < ...
5674 # Restore the trace value again.
5677 } ## end sub dump_trace
5681 C<action()> takes input provided as the argument to an add-action command,
5682 either pre- or post-, and makes sure it's a complete command. It doesn't do
5683 any fancy parsing; it just keeps reading input until it gets a string
5684 without a trailing backslash.
5691 while ( $action =~ s/\\$// ) {
5693 # We have a backslash on the end. Read more.
5695 } ## end while ($action =~ s/\\$//)
5697 # Return the assembled action.
5703 This routine mostly just packages up a regular expression to be used
5704 to check that the thing it's being matched against has properly-matched
5707 Of note is the definition of the $balanced_brace_re global via ||=, which
5708 speeds things up by only creating the qr//'ed expression once; if it's
5709 already defined, we don't try to define it again. A speed hack.
5715 # I hate using globals!
5716 $balanced_brace_re ||= qr{
5719 (?> [^{}] + ) # Non-parens without backtracking
5721 (??{ $balanced_brace_re }) # Group with matching parens
5725 return $_[0] !~ m/$balanced_brace_re/;
5726 } ## end sub unbalanced
5730 C<gets()> is a primitive (very primitive) routine to read continuations.
5731 It was devised for reading continuations for actions.
5732 it just reads more input with X<C<readline()>> and returns it.
5737 &readline("cont: ");
5740 =head2 C<DB::system()> - handle calls to<system()> without messing up the debugger
5742 The C<system()> function assumes that it can just go ahead and use STDIN and
5743 STDOUT, but under the debugger, we want it to use the debugger's input and
5746 C<DB::system()> socks away the program's STDIN and STDOUT, and then substitutes
5747 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
5748 and then puts everything back again.
5754 # We save, change, then restore STDIN and STDOUT to avoid fork() since
5755 # some non-Unix systems can do system() but have problems with fork().
5756 open( SAVEIN, "<&STDIN" ) || &warn("Can't save STDIN");
5757 open( SAVEOUT, ">&STDOUT" ) || &warn("Can't save STDOUT");
5758 open( STDIN, "<&IN" ) || &warn("Can't redirect STDIN");
5759 open( STDOUT, ">&OUT" ) || &warn("Can't redirect STDOUT");
5761 # XXX: using csh or tcsh destroys sigint retvals!
5763 open( STDIN, "<&SAVEIN" ) || &warn("Can't restore STDIN");
5764 open( STDOUT, ">&SAVEOUT" ) || &warn("Can't restore STDOUT");
5768 # most of the $? crud was coping with broken cshisms
5770 &warn( "(Command exited ", ( $? >> 8 ), ")\n" );
5774 "(Command died of SIG#",
5776 ( ( $? & 128 ) ? " -- core dumped" : "" ),
5785 =head1 TTY MANAGEMENT
5787 The subs here do some of the terminal management for multiple debuggers.
5791 Top-level function called when we want to set up a new terminal for use
5794 If the C<noTTY> debugger option was set, we'll either use the terminal
5795 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
5796 to find one. If we're a forked debugger, we call C<resetterm> to try to
5797 get a whole new terminal if we can.
5799 In either case, we set up the terminal next. If the C<ReadLine> option was
5800 true, we'll get a C<Term::ReadLine> object for the current terminal and save
5801 the appropriate attributes. We then
5807 # Load Term::Readline, but quietly; don't debug it and don't trace it.
5810 eval { require Term::ReadLine } or die $@;
5812 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
5815 my ( $i, $o ) = split $tty, /,/;
5816 $o = $i unless defined $o;
5817 open( IN, "<$i" ) or die "Cannot open TTY `$i' for read: $!";
5818 open( OUT, ">$o" ) or die "Cannot open TTY `$o' for write: $!";
5821 my $sel = select($OUT);
5826 # We don't have a TTY - try to find one via Term::Rendezvous.
5828 eval "require Term::Rendezvous;" or die;
5830 # See if we have anything to pass to Term::Rendezvous.
5831 # Use /tmp/perldbtty$$ if not.
5832 my $rv = $ENV{PERLDB_NOTTY} || "/tmp/perldbtty$$";
5834 # Rendezvous and get the filehandles.
5835 my $term_rv = new Term::Rendezvous $rv;
5837 $OUT = $term_rv->OUT;
5838 } ## end else [ if ($tty)
5839 } ## end if ($notty)
5841 # We're a daughter debugger. Try to fork off another TTY.
5842 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
5846 # If we shouldn't use Term::ReadLine, don't.
5848 $term = new Term::ReadLine::Stub 'perldb', $IN, $OUT;
5851 # We're using Term::ReadLine. Get all the attributes for this terminal.
5853 $term = new Term::ReadLine 'perldb', $IN, $OUT;
5855 $rl_attribs = $term->Attribs;
5856 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
5857 if defined $rl_attribs->{basic_word_break_characters}
5858 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
5859 $rl_attribs->{special_prefixes} = '$@&%';
5860 $rl_attribs->{completer_word_break_characters} .= '$@&%';
5861 $rl_attribs->{completion_function} = \&db_complete;
5862 } ## end else [ if (!$rl)
5864 # Set up the LINEINFO filehandle.
5865 $LINEINFO = $OUT unless defined $LINEINFO;
5866 $lineinfo = $console unless defined $lineinfo;
5870 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
5871 $term->SetHistory(@hist);
5874 # XXX Ornaments are turned on unconditionally, which is not
5875 # always a good thing.
5876 ornaments($ornaments) if defined $ornaments;
5878 } ## end sub setterm
5880 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
5882 When the process being debugged forks, or the process invokes a command
5883 via C<system()> which starts a new debugger, we need to be able to get a new
5884 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
5885 fight over the terminal, and you can never quite be sure who's going to get the
5886 input you're typing.
5888 C<get_fork_TTY> is a glob-aliased function which calls the real function that
5889 is tasked with doing all the necessary operating system mojo to get a new
5890 TTY (and probably another window) and to direct the new debugger to read and
5893 The debugger provides C<get_fork_TTY> functions which work for X Windows and
5894 OS/2. Other systems are not supported. You are encouraged to write
5895 C<get_fork_TTY> functions which work for I<your> platform and contribute them.
5897 =head3 C<xterm_get_fork_TTY>
5899 This function provides the C<get_fork_TTY> function for X windows. If a
5900 program running under the debugger forks, a new <xterm> window is opened and
5901 the subsidiary debugger is directed there.
5903 The C<open()> call is of particular note here. We have the new C<xterm>
5904 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
5905 command (which prints the device name of the TTY we'll want to use for input
5906 and output to STDOUT, then C<sleep> for a very long time, routing this output
5907 to file number 3. This way we can simply read from the <XT> filehandle (which
5908 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
5910 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
5915 sub xterm_get_fork_TTY {
5916 ( my $name = $0 ) =~ s,^.*[/\\],,s;
5918 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
5921 # Get the output from 'tty' and clean it up a little.
5925 $pidprompt = ''; # Shown anyway in titlebar
5927 # There's our new TTY.
5929 } ## end sub xterm_get_fork_TTY
5931 =head3 C<os2_get_fork_TTY>
5933 XXX It behooves an OS/2 expert to write the necessary documentation for this!
5937 # This example function resets $IN, $OUT itself
5938 sub os2_get_fork_TTY {
5939 local $^F = 40; # XXXX Fixme!
5941 my ( $in1, $out1, $in2, $out2 );
5943 # Having -d in PERL5OPT would lead to a disaster...
5944 local $ENV{PERL5OPT} = $ENV{PERL5OPT} if $ENV{PERL5OPT};
5945 $ENV{PERL5OPT} =~ s/(?:^|(?<=\s))-d\b// if $ENV{PERL5OPT};
5946 $ENV{PERL5OPT} =~ s/(?:^|(?<=\s))-d\B/-/ if $ENV{PERL5OPT};
5947 print $OUT "Making kid PERL5OPT->`$ENV{PERL5OPT}'.\n" if $ENV{PERL5OPT};
5948 local $ENV{PERL5LIB} = $ENV{PERL5LIB} ? $ENV{PERL5LIB} : $ENV{PERLLIB};
5949 $ENV{PERL5LIB} = '' unless defined $ENV{PERL5LIB};
5950 $ENV{PERL5LIB} = join ';', @ini_INC, split /;/, $ENV{PERL5LIB};
5951 ( my $name = $0 ) =~ s,^.*[/\\],,s;
5956 and pipe $in2, $out2
5958 # system P_SESSION will fail if there is another process
5959 # in the same session with a "dependent" asynchronous child session.
5961 $rl, fileno $in1, fileno $out2, "Daughter Perl debugger $pids $name"
5964 ( $kpid = CORE::system 4, $^X, '-we',
5965 <<'ES', @args ) >= 0 # P_SESSION
5966 END {sleep 5 unless $loaded}
5967 BEGIN {open STDIN, '</dev/con' or warn "reopen stdin: $!"}
5970 my ($rl, $in) = (shift, shift); # Read from $in and pass through
5972 system P_NOWAIT, $^X, '-we', <<EOS or die "Cannot start a grandkid";
5973 open IN, '<&=$in' or die "open <&=$in: \$!";
5974 \$| = 1; print while sysread IN, \$_, 1<<16;
5978 open OUT, ">&=$out" or die "Cannot open &=$out for writing: $!";
5980 require Term::ReadKey if $rl;
5981 Term::ReadKey::ReadMode(4) if $rl; # Nodelay on kbd. Pipe is automatically nodelay...
5982 print while sysread STDIN, $_, 1<<($rl ? 16 : 0);
5984 or warn "system P_SESSION: $!, $^E" and 0
5990 $pidprompt = ''; # Shown anyway in titlebar
5991 reset_IN_OUT( $in2, $out1 );
5993 return ''; # Indicate that reset_IN_OUT is called
5994 } ## end if (pipe $in1, $out1 and...
5996 } ## end sub os2_get_fork_TTY
5998 =head2 C<create_IN_OUT($flags)>
6000 Create a new pair of filehandles, pointing to a new TTY. If impossible,
6001 try to diagnose why.
6007 =item * 1 - Don't know how to create a new TTY.
6009 =item * 2 - Debugger has forked, but we can't get a new TTY.
6011 =item * 4 - standard debugger startup is happening.
6017 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
6019 # If we know how to get a new TTY, do it! $in will have
6020 # the TTY name if get_fork_TTY works.
6021 my $in = &get_fork_TTY if defined &get_fork_TTY;
6023 # It used to be that
6024 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
6026 if ( not defined $in ) {
6029 # We don't know how.
6030 print_help(<<EOP) if $why == 1;
6031 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
6035 print_help(<<EOP) if $why == 2;
6036 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
6037 This may be an asynchronous session, so the parent debugger may be active.
6040 # Note that both debuggers are fighting over the same input.
6041 print_help(<<EOP) if $why != 4;
6042 Since two debuggers fight for the same TTY, input is severely entangled.
6046 I know how to switch the output to a different window in xterms
6047 and OS/2 consoles only. For a manual switch, put the name of the created I<TTY>
6048 in B<\$DB::fork_TTY>, or define a function B<DB::get_fork_TTY()> returning this.
6050 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
6051 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
6054 } ## end if (not defined $in)
6055 elsif ( $in ne '' ) {
6059 $console = ''; # Indicate no need to open-from-the-console
6062 } ## end sub create_IN_OUT
6066 Handles rejiggering the prompt when we've forked off a new debugger.
6068 If the new debugger happened because of a C<system()> that invoked a
6069 program under the debugger, the arrow between the old pid and the new
6070 in the prompt has I<two> dashes instead of one.
6072 We take the current list of pids and add this one to the end. If there
6073 isn't any list yet, we make one up out of the initial pid associated with
6074 the terminal and our new pid, sticking an arrow (either one-dashed or
6075 two dashed) in between them.
6077 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
6078 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
6083 sub resetterm { # We forked, so we need a different TTY
6085 # Needs to be passed to create_IN_OUT() as well.
6088 # resetterm(2): got in here because of a system() starting a debugger.
6089 # resetterm(1): just forked.
6090 my $systemed = $in > 1 ? '-' : '';
6092 # If there's already a list of pids, add this to the end.
6094 $pids =~ s/\]/$systemed->$$]/;
6097 # No pid list. Time to make one.
6099 $pids = "[$term_pid->$$]";
6102 # The prompt we're going to be using for this debugger.
6105 # We now 0wnz this terminal.
6108 # Just return if we're not supposed to try to create a new TTY.
6109 return unless $CreateTTY & $in;
6111 # Try to create a new IN/OUT pair.
6113 } ## end sub resetterm
6117 First, we handle stuff in the typeahead buffer. If there is any, we shift off
6118 the next line, print a message saying we got it, add it to the terminal
6119 history (if possible), and return it.
6121 If there's nothing in the typeahead buffer, check the command filehandle stack.
6122 If there are any filehandles there, read from the last one, and return the line
6123 if we got one. If not, we pop the filehandle off and close it, and try the
6124 next one up the stack.
6126 If we've emptied the filehandle stack, we check to see if we've got a socket
6127 open, and we read that and return it if we do. If we don't, we just call the
6128 core C<readline()> and return its value.
6134 # Localize to prevent it from being smashed in the program being debugged.
6137 # Pull a line out of the typeahead if there's stuff there.
6140 # How many lines left.
6141 my $left = @typeahead;
6143 # Get the next line.
6144 my $got = shift @typeahead;
6146 # Print a message saying we got input from the typeahead.
6148 print $OUT "auto(-$left)", shift, $got, "\n";
6150 # Add it to the terminal history (if possible).
6151 $term->AddHistory($got)
6153 and defined $term->Features->{addHistory};
6155 } ## end if (@typeahead)
6157 # We really need to read some input. Turn off entry/exit trace and
6158 # return value printing.
6162 # If there are stacked filehandles to read from ...
6165 # Read from the last one in the stack.
6166 my $line = CORE::readline( $cmdfhs[-1] );
6168 # If we got a line ...
6170 ? ( print $OUT ">> $line" and return $line ) # Echo and return
6171 : close pop @cmdfhs; # Pop and close
6172 } ## end while (@cmdfhs)
6174 # Nothing on the filehandle stack. Socket?
6175 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
6177 # Send anyting we have to send.
6178 $OUT->write( join( '', @_ ) );
6180 # Receive anything there is to receive.
6182 $IN->recv( $stuff, 2048 ); # XXX "what's wrong with sysread?"
6183 # XXX Don't know. You tell me.
6187 } ## end if (ref $OUT and UNIVERSAL::isa...
6189 # No socket. Just read from the terminal.
6191 $term->readline(@_);
6193 } ## end sub readline
6195 =head1 OPTIONS SUPPORT ROUTINES
6197 These routines handle listing and setting option values.
6199 =head2 C<dump_option> - list the current value of an option setting
6201 This routine uses C<option_val> to look up the value for an option.
6202 It cleans up escaped single-quotes and then displays the option and
6208 my ( $opt, $val ) = @_;
6209 $val = option_val( $opt, 'N/A' );
6210 $val =~ s/([\\\'])/\\$1/g;
6211 printf $OUT "%20s = '%s'\n", $opt, $val;
6212 } ## end sub dump_option
6214 sub options2remember {
6215 foreach my $k (@RememberOnROptions) {
6216 $option{$k} = option_val( $k, 'N/A' );
6221 =head2 C<option_val> - find the current value of an option
6223 This can't just be a simple hash lookup because of the indirect way that
6224 the option values are stored. Some are retrieved by calling a subroutine,
6225 some are just variables.
6227 You must supply a default value to be used in case the option isn't set.
6232 my ( $opt, $default ) = @_;
6235 # Does this option exist, and is it a variable?
6236 # If so, retrieve the value via the value in %optionVars.
6237 if ( defined $optionVars{$opt}
6238 and defined ${ $optionVars{$opt} } )
6240 $val = ${ $optionVars{$opt} };
6243 # Does this option exist, and it's a subroutine?
6244 # If so, call the subroutine via the ref in %optionAction
6245 # and capture the value.
6246 elsif ( defined $optionAction{$opt}
6247 and defined &{ $optionAction{$opt} } )
6249 $val = &{ $optionAction{$opt} }();
6252 # If there's an action or variable for the supplied option,
6253 # but no value was set, use the default.
6254 elsif (defined $optionAction{$opt} and not defined $option{$opt}
6255 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
6260 # Otherwise, do the simple hash lookup.
6262 $val = $option{$opt};
6265 # If the value isn't defined, use the default.
6266 # Then return whatever the value is.
6267 $val = $default unless defined $val;
6269 } ## end sub option_val
6271 =head2 C<parse_options>
6273 Handles the parsing and execution of option setting/displaying commands.
6275 An option entered by itself is assumed to be 'set me to 1' (the default value)
6276 if the option is a boolean one. If not, the user is prompted to enter a valid
6277 value or to query the current value (via 'option? ').
6279 If 'option=value' is entered, we try to extract a quoted string from the
6280 value (if it is quoted). If it's not, we just use the whole value as-is.
6282 We load any modules required to service this option, and then we set it: if
6283 it just gets stuck in a variable, we do that; if there's a subroutine to
6284 handle setting the option, we call that.
6286 Finally, if we're running in interactive mode, we display the effect of the
6287 user's command back to the terminal, skipping this if we're setting things
6288 during initialization.
6296 # These options need a value. Don't allow them to be clobbered by accident.
6297 my %opt_needs_val = map { ( $_ => 1 ) } qw{
6298 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
6299 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
6305 # Clean off excess leading whitespace.
6308 # Options are always all word characters, followed by a non-word
6310 s/^(\w+)(\W?)// or print( $OUT "Invalid option `$_'\n" ), last;
6311 my ( $opt, $sep ) = ( $1, $2 );
6313 # Make sure that such an option exists.
6314 my $matches = grep( /^\Q$opt/ && ( $option = $_ ), @options )
6315 || grep( /^\Q$opt/i && ( $option = $_ ), @options );
6317 print( $OUT "Unknown option `$opt'\n" ), next unless $matches;
6318 print( $OUT "Ambiguous option `$opt'\n" ), next if $matches > 1;
6321 # '?' as separator means query, but must have whitespace after it.
6322 if ( "?" eq $sep ) {
6323 print( $OUT "Option query `$opt?' followed by non-space `$_'\n" ),
6327 #&dump_option($opt);
6328 } ## end if ("?" eq $sep)
6330 # Separator is whitespace (or just a carriage return).
6331 # They're going for a default, which we assume is 1.
6332 elsif ( $sep !~ /\S/ ) {
6334 $val = "1"; # this is an evil default; make 'em set it!
6337 # Separator is =. Trying to set a value.
6338 elsif ( $sep eq "=" ) {
6340 # If quoted, extract a quoted string.
6341 if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
6343 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
6346 # Not quoted. Use the whole thing. Warn about 'option='.
6350 print OUT qq(Option better cleared using $opt=""\n)
6352 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
6354 } ## end elsif ($sep eq "=")
6356 # "Quoted" with [], <>, or {}.
6357 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
6359 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
6360 s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
6361 or print( $OUT "Unclosed option value `$opt$sep$_'\n" ), last;
6362 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
6363 } ## end else [ if ("?" eq $sep)
6365 # Exclude non-booleans from getting set to 1 by default.
6366 if ( $opt_needs_val{$option} && $val_defaulted ) {
6367 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
6369 "Option `$opt' is non-boolean. Use `$cmd $option=VAL' to set, `$cmd $option?' to query\n";
6371 } ## end if ($opt_needs_val{$option...
6373 # Save the option value.
6374 $option{$option} = $val if defined $val;
6376 # Load any module that this option requires.
6380 require '$optionRequire{$option}';
6382 } || die # XXX: shouldn't happen
6383 if defined $optionRequire{$option}
6387 # Stick it in the proper variable if it goes in a variable.
6388 ${ $optionVars{$option} } = $val
6389 if defined $optionVars{$option}
6392 # Call the appropriate sub if it gets set via sub.
6393 &{ $optionAction{$option} }($val)
6394 if defined $optionAction{$option}
6395 && defined &{ $optionAction{$option} }
6398 # Not initialization - echo the value we set it to.
6399 dump_option($option) unless $OUT eq \*STDERR;
6400 } ## end while (length)
6401 } ## end sub parse_options
6403 =head1 RESTART SUPPORT
6405 These routines are used to store (and restore) lists of items in environment
6406 variables during a restart.
6410 Set_list packages up items to be stored in a set of environment variables
6411 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
6412 the values). Values outside the standard ASCII charset are stored by encoding
6413 then as hexadecimal values.
6418 my ( $stem, @list ) = @_;
6421 # VAR_n: how many we have. Scalar assignment gets the number of items.
6422 $ENV{"${stem}_n"} = @list;
6424 # Grab each item in the list, escape the backslashes, encode the non-ASCII
6425 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
6426 for $i ( 0 .. $#list ) {
6428 $val =~ s/\\/\\\\/g;
6429 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
6430 $ENV{"${stem}_$i"} = $val;
6431 } ## end for $i (0 .. $#list)
6432 } ## end sub set_list
6436 Reverse the set_list operation: grab VAR_n to see how many we should be getting
6437 back, and then pull VAR_0, VAR_1. etc. back out.
6444 my $n = delete $ENV{"${stem}_n"};
6446 for $i ( 0 .. $n - 1 ) {
6447 $val = delete $ENV{"${stem}_$i"};
6448 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
6452 } ## end sub get_list
6454 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
6458 The C<catch()> subroutine is the essence of fast and low-impact. We simply
6459 set an already-existing global scalar variable to a constant value. This
6460 avoids allocating any memory possibly in the middle of something that will
6461 get all confused if we do.
6467 return; # Put nothing on the stack - malloc/free land!
6472 C<warn> emits a warning, by joining together its arguments and printing
6473 them, with couple of fillips.
6475 If the composited message I<doesn't> end with a newline, we automatically
6476 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
6477 to be set to the filehandle to be used to output warnings; it makes no
6478 assumptions about what filehandles are available.
6483 my ($msg) = join( "", @_ );
6484 $msg .= ": $!\n" unless $msg =~ /\n$/;
6489 =head1 INITIALIZATION TTY SUPPORT
6491 =head2 C<reset_IN_OUT>
6493 This routine handles restoring the debugger's input and output filehandles
6494 after we've tried and failed to move them elsewhere. In addition, it assigns
6495 the debugger's output filehandle to $LINEINFO if it was already open there.
6500 my $switch_li = $LINEINFO eq $OUT;
6502 # If there's a term and it's able to get a new tty, try to get one.
6503 if ( $term and $term->Features->{newTTY} ) {
6504 ( $IN, $OUT ) = ( shift, shift );
6505 $term->newTTY( $IN, $OUT );
6508 # This term can't get a new tty now. Better luck later.
6510 &warn("Too late to set IN/OUT filehandles, enabled on next `R'!\n");
6513 # Set the filehndles up as they were.
6515 ( $IN, $OUT ) = ( shift, shift );
6518 # Unbuffer the output filehandle.
6519 my $o = select $OUT;
6523 # Point LINEINFO to the same output filehandle if it was there before.
6524 $LINEINFO = $OUT if $switch_li;
6525 } ## end sub reset_IN_OUT
6527 =head1 OPTION SUPPORT ROUTINES
6529 The following routines are used to process some of the more complicated
6534 Sets the input and output filehandles to the specified files or pipes.
6535 If the terminal supports switching, we go ahead and do it. If not, and
6536 there's already a terminal in place, we save the information to take effect
6539 If there's no terminal yet (for instance, during debugger initialization),
6540 we go ahead and set C<$console> and C<$tty> to the file indicated.
6545 if ( @_ and $term and $term->Features->{newTTY} ) {
6547 # This terminal supports switching to a new TTY.
6548 # Can be a list of two files, or on string containing both names,
6550 # XXX Should this perhaps be an assignment from @_?
6551 my ( $in, $out ) = shift;
6554 # Split list apart if supplied.
6555 ( $in, $out ) = split /,/, $in, 2;
6559 # Use the same file for both input and output.
6563 # Open file onto the debugger's filehandles, if you can.
6564 open IN, $in or die "cannot open `$in' for read: $!";
6565 open OUT, ">$out" or die "cannot open `$out' for write: $!";
6567 # Swap to the new filehandles.
6568 reset_IN_OUT( \*IN, \*OUT );
6570 # Save the setting for later.
6572 } ## end if (@_ and $term and $term...
6574 # Terminal doesn't support new TTY, or doesn't support readline.
6575 # Can't do it now, try restarting.
6576 &warn("Too late to set TTY, enabled on next `R'!\n") if $term and @_;
6578 # Useful if done through PERLDB_OPTS:
6579 $console = $tty = shift if @_;
6581 # Return whatever the TTY is.
6587 Sets the C<$notty> global, controlling whether or not the debugger tries to
6588 get a terminal to read from. If called after a terminal is already in place,
6589 we save the value to use it if we're restarted.
6595 &warn("Too late to set noTTY, enabled on next `R'!\n") if @_;
6597 $notty = shift if @_;
6603 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
6604 (essentially, no C<readline> processing on this "terminal"). Otherwise, we
6605 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
6606 the value in case a restart is done so we can change it then.
6612 &warn("Too late to set ReadLine, enabled on next `R'!\n") if @_;
6616 } ## end sub ReadLine
6618 =head2 C<RemotePort>
6620 Sets the port that the debugger will try to connect to when starting up.
6621 If the terminal's already been set up, we can't do it, but we remember the
6622 setting in case the user does a restart.
6628 &warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
6630 $remoteport = shift if @_;
6632 } ## end sub RemotePort
6636 Checks with the terminal to see if C<Tk> is running, and returns true or
6637 false. Returns false if the current terminal doesn't support C<readline>.
6642 if ( ${ $term->Features }{tkRunning} ) {
6643 return $term->tkRunning(@_);
6647 print $OUT "tkRunning not supported by current ReadLine package.\n";
6650 } ## end sub tkRunning
6654 Sets nonstop mode. If a terminal's already been set up, it's too late; the
6655 debugger remembers the setting in case you restart, though.
6661 &warn("Too late to set up NonStop mode, enabled on next `R'!\n")
6664 $runnonstop = shift if @_;
6666 } ## end sub NonStop
6670 &warn("Some flag changes could not take effect until next 'R'!\n")
6673 $^P = parse_DollarCaretP_flags(shift) if @_;
6674 expand_DollarCaretP_flags($^P);
6677 sub OnlyAssertions {
6679 &warn("Too late to set up OnlyAssertions mode, enabled on next 'R'!\n")
6683 unless ( defined $ini_assertion ) {
6685 &warn("Current Perl interpreter doesn't support assertions");
6690 unless ($ini_assertion) {
6691 print "Assertions will be active on next 'R'!\n";
6694 $^P &= ~$DollarCaretP_flags{PERLDBf_SUB};
6695 $^P |= $DollarCaretP_flags{PERLDBf_ASSERTION};
6698 $^P |= $DollarCaretP_flags{PERLDBf_SUB};
6701 !( $^P & $DollarCaretP_flags{PERLDBf_SUB} ) || 0;
6706 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
6714 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
6721 Sets the shell escape command, and generates a printable copy to be used
6728 # If we got an argument, meta-quote it, and add '\b' if it
6729 # ends in a word character.
6731 $sh = quotemeta shift;
6732 $sh .= "\\b" if $sh =~ /\w$/;
6735 # Generate the printable version for the help:
6736 $psh = $sh; # copy it
6737 $psh =~ s/\\b$//; # Take off trailing \b if any
6738 $psh =~ s/\\(.)/$1/g; # De-escape
6739 $psh; # return the printable version
6740 } ## end sub shellBang
6744 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
6745 was passed as the argument. (This means you can't override the terminal's
6751 if ( defined $term ) {
6753 # We don't want to show warning backtraces, but we do want die() ones.
6754 local ( $warnLevel, $dieLevel ) = ( 0, 1 );
6756 # No ornaments if the terminal doesn't support them.
6757 return '' unless $term->Features->{ornaments};
6758 eval { $term->ornaments(@_) } || '';
6761 # Use what was passed in if we can't determine it ourselves.
6765 } ## end sub ornaments
6767 =head2 C<recallCommand>
6769 Sets the recall command, and builds a printable version which will appear in
6776 # If there is input, metaquote it. Add '\b' if it ends with a word
6779 $rc = quotemeta shift;
6780 $rc .= "\\b" if $rc =~ /\w$/;
6783 # Build it into a printable version.
6784 $prc = $rc; # Copy it
6785 $prc =~ s/\\b$//; # Remove trailing \b
6786 $prc =~ s/\\(.)/$1/g; # Remove escapes
6787 $prc; # Return the printable version
6788 } ## end sub recallCommand
6790 =head2 C<LineInfo> - where the line number information goes
6792 Called with no arguments, returns the file or pipe that line info should go to.
6794 Called with an argument (a file or a pipe), it opens that onto the
6795 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
6796 file or pipe again to the caller.
6801 return $lineinfo unless @_;
6804 # If this is a valid "thing to be opened for output", tack a
6805 # '>' onto the front.
6806 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
6808 # If this is a pipe, the stream points to a slave editor.
6809 $slave_editor = ( $stream =~ /^\|/ );
6811 # Open it up and unbuffer it.
6812 open( LINEINFO, "$stream" ) || &warn("Cannot open `$stream' for write");
6813 $LINEINFO = \*LINEINFO;
6814 my $save = select($LINEINFO);
6818 # Hand the file or pipe back again.
6820 } ## end sub LineInfo
6822 =head1 COMMAND SUPPORT ROUTINES
6824 These subroutines provide functionality for various commands.
6826 =head2 C<list_modules>
6828 For the C<M> command: list modules loaded and their versions.
6829 Essentially just runs through the keys in %INC, picks up the
6830 $VERSION package globals from each package, gets the file name, and formats the
6831 information for output.
6835 sub list_modules { # versions
6839 # keys are the "as-loaded" name, values are the fully-qualified path
6840 # to the file itself.
6842 $file = $_; # get the module name
6843 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
6844 s,/,::,g; # change '/' to '::'
6845 s/^perl5db$/DB/; # Special case: debugger
6846 # moves to package DB
6847 s/^Term::ReadLine::readline$/readline/; # simplify readline
6849 # If the package has a $VERSION package global (as all good packages
6850 # should!) decode it and save as partial message.
6851 if ( defined ${ $_ . '::VERSION' } ) {
6852 $version{$file} = "${ $_ . '::VERSION' } from ";
6855 # Finish up the message with the file the package came from.
6856 $version{$file} .= $INC{$file};
6857 } ## end for (keys %INC)
6859 # Hey, dumpit() formats a hash nicely, so why not use it?
6860 dumpit( $OUT, \%version );
6861 } ## end sub list_modules
6865 Sets up the monster string used to format and print the help.
6867 =head3 HELP MESSAGE FORMAT
6869 The help message is a peculiar format unto itself; it mixes C<pod> 'ornaments'
6870 (BE<lt>E<gt>, IE<gt>E<lt>) with tabs to come up with a format that's fairly
6871 easy to parse and portable, but which still allows the help to be a little
6872 nicer than just plain text.
6874 Essentially, you define the command name (usually marked up with BE<gt>E<lt>
6875 and IE<gt>E<lt>), followed by a tab, and then the descriptive text, ending in a newline. The descriptive text can also be marked up in the same way. If you
6876 need to continue the descriptive text to another line, start that line with
6877 just tabs and then enter the marked-up text.
6879 If you are modifying the help text, I<be careful>. The help-string parser is
6880 not very sophisticated, and if you don't follow these rules it will mangle the
6881 help beyond hope until you fix the string.
6887 # XXX: make sure there are tabs between the command and explanation,
6888 # or print_help will screw up your formatting if you have
6889 # eeevil ornaments enabled. This is an insane mess.
6892 Help is currently only available for the new 5.8 command set.
6893 No help is available for the old command set.
6894 We assume you know what you're doing if you switch to it.
6897 B<s> [I<expr>] Single step [in I<expr>].
6898 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
6899 <B<CR>> Repeat last B<n> or B<s> command.
6900 B<r> Return from current subroutine.
6901 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
6902 at the specified position.
6903 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
6904 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
6905 B<l> I<line> List single I<line>.
6906 B<l> I<subname> List first window of lines from subroutine.
6907 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
6908 B<l> List next window of lines.
6909 B<-> List previous window of lines.
6910 B<v> [I<line>] View window around I<line>.
6911 B<.> Return to the executed line.
6912 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
6913 I<filename> may be either the full name of the file, or a regular
6914 expression matching the full file name:
6915 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
6916 Evals (with saved bodies) are considered to be filenames:
6917 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
6918 (in the order of execution).
6919 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
6920 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
6921 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
6922 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
6923 B<t> Toggle trace mode.
6924 B<t> I<expr> Trace through execution of I<expr>.
6925 B<b> Sets breakpoint on current line)
6926 B<b> [I<line>] [I<condition>]
6927 Set breakpoint; I<line> defaults to the current execution line;
6928 I<condition> breaks if it evaluates to true, defaults to '1'.
6929 B<b> I<subname> [I<condition>]
6930 Set breakpoint at first line of subroutine.
6931 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
6932 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
6933 B<b> B<postpone> I<subname> [I<condition>]
6934 Set breakpoint at first line of subroutine after
6936 B<b> B<compile> I<subname>
6937 Stop after the subroutine is compiled.
6938 B<B> [I<line>] Delete the breakpoint for I<line>.
6939 B<B> I<*> Delete all breakpoints.
6940 B<a> [I<line>] I<command>
6941 Set an action to be done before the I<line> is executed;
6942 I<line> defaults to the current execution line.
6943 Sequence is: check for breakpoint/watchpoint, print line
6944 if necessary, do action, prompt user if necessary,
6947 B<A> [I<line>] Delete the action for I<line>.
6948 B<A> I<*> Delete all actions.
6949 B<w> I<expr> Add a global watch-expression.
6951 B<W> I<expr> Delete a global watch-expression.
6952 B<W> I<*> Delete all watch-expressions.
6953 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
6954 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
6955 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
6956 B<x> I<expr> Evals expression in list context, dumps the result.
6957 B<m> I<expr> Evals expression in list context, prints methods callable
6958 on the first element of the result.
6959 B<m> I<class> Prints methods callable via the given class.
6960 B<M> Show versions of loaded modules.
6961 B<i> I<class> Prints nested parents of given class.
6962 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
6963 B<P> Something to do with assertions...
6965 B<<> ? List Perl commands to run before each prompt.
6966 B<<> I<expr> Define Perl command to run before each prompt.
6967 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
6968 B<< *> Delete the list of perl commands to run before each prompt.
6969 B<>> ? List Perl commands to run after each prompt.
6970 B<>> I<expr> Define Perl command to run after each prompt.
6971 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
6972 B<>>B< *> Delete the list of Perl commands to run after each prompt.
6973 B<{> I<db_command> Define debugger command to run before each prompt.
6974 B<{> ? List debugger commands to run before each prompt.
6975 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
6976 B<{ *> Delete the list of debugger commands to run before each prompt.
6977 B<$prc> I<number> Redo a previous command (default previous command).
6978 B<$prc> I<-number> Redo number'th-to-last command.
6979 B<$prc> I<pattern> Redo last command that started with I<pattern>.
6980 See 'B<O> I<recallCommand>' too.
6981 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
6986 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
6988 See 'B<O> I<shellBang>' too.
6989 B<source> I<file> Execute I<file> containing debugger commands (may nest).
6990 B<save> I<file> Save current debugger session (actual history) to I<file>.
6991 B<rerun> Rerun session to current position.
6992 B<rerun> I<n> Rerun session to numbered command.
6993 B<rerun> I<-n> Rerun session to number'th-to-last command.
6994 B<H> I<-number> Display last number commands (default all).
6995 B<H> I<*> Delete complete history.
6996 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
6997 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
6998 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
6999 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7000 I<command> Execute as a perl statement in current package.
7001 B<R> Pure-man-restart of debugger, some of debugger state
7002 and command-line options may be lost.
7003 Currently the following settings are preserved:
7004 history, breakpoints and actions, debugger B<O>ptions
7005 and the following command-line options: I<-w>, I<-I>, I<-e>.
7007 B<o> [I<opt>] ... Set boolean option to true
7008 B<o> [I<opt>B<?>] Query options
7009 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7010 Set options. Use quotes in spaces in value.
7011 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7012 I<pager> program for output of \"|cmd\";
7013 I<tkRunning> run Tk while prompting (with ReadLine);
7014 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7015 I<inhibit_exit> Allows stepping off the end of the script.
7016 I<ImmediateStop> Debugger should stop as early as possible.
7017 I<RemotePort> Remote hostname:port for remote debugging
7018 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7019 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7020 I<compactDump>, I<veryCompact> change style of array and hash dump;
7021 I<globPrint> whether to print contents of globs;
7022 I<DumpDBFiles> dump arrays holding debugged files;
7023 I<DumpPackages> dump symbol tables of packages;
7024 I<DumpReused> dump contents of \"reused\" addresses;
7025 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7026 I<bareStringify> Do not print the overload-stringified value;
7027 Other options include:
7028 I<PrintRet> affects printing of return value after B<r> command,
7029 I<frame> affects printing messages on subroutine entry/exit.
7030 I<AutoTrace> affects printing messages on possible breaking points.
7031 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7032 I<ornaments> affects screen appearance of the command line.
7033 I<CreateTTY> bits control attempts to create a new TTY on events:
7034 1: on fork() 2: debugger is started inside debugger
7036 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7037 You can put additional initialization options I<TTY>, I<noTTY>,
7038 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7039 `B<R>' after you set them).
7041 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7042 B<h> Summary of debugger commands.
7043 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7044 B<h h> Long help for debugger commands
7045 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7046 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7047 Set B<\$DB::doccmd> to change viewer.
7049 Type `|h h' for a paged display if this was too hard to read.
7051 "; # Fix balance of vi % matching: }}}}
7053 # note: tabs in the following section are not-so-helpful
7054 $summary = <<"END_SUM";
7055 I<List/search source lines:> I<Control script execution:>
7056 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7057 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7058 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
7059 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7060 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7061 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
7062 I<Debugger controls:> B<L> List break/watch/actions
7063 B<o> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7064 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7065 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
7066 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7067 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
7068 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
7069 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
7070 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7071 B<q> or B<^D> Quit B<R> Attempt a restart
7072 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7073 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7074 B<p> I<expr> Print expression (uses script's current package).
7075 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7076 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7077 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
7078 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7079 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7082 # ')}}; # Fix balance of vi % matching
7084 # and this is really numb...
7087 B<s> [I<expr>] Single step [in I<expr>].
7088 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7089 B<CR>> Repeat last B<n> or B<s> command.
7090 B<r> Return from current subroutine.
7091 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7092 at the specified position.
7093 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7094 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7095 B<l> I<line> List single I<line>.
7096 B<l> I<subname> List first window of lines from subroutine.
7097 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7098 B<l> List next window of lines.
7099 B<-> List previous window of lines.
7100 B<w> [I<line>] List window around I<line>.
7101 B<.> Return to the executed line.
7102 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7103 I<filename> may be either the full name of the file, or a regular
7104 expression matching the full file name:
7105 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7106 Evals (with saved bodies) are considered to be filenames:
7107 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7108 (in the order of execution).
7109 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7110 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7111 B<L> List all breakpoints and actions.
7112 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7113 B<t> Toggle trace mode.
7114 B<t> I<expr> Trace through execution of I<expr>.
7115 B<b> [I<line>] [I<condition>]
7116 Set breakpoint; I<line> defaults to the current execution line;
7117 I<condition> breaks if it evaluates to true, defaults to '1'.
7118 B<b> I<subname> [I<condition>]
7119 Set breakpoint at first line of subroutine.
7120 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7121 B<b> B<load> I<filename> Set breakpoint on `require'ing the given file.
7122 B<b> B<postpone> I<subname> [I<condition>]
7123 Set breakpoint at first line of subroutine after
7125 B<b> B<compile> I<subname>
7126 Stop after the subroutine is compiled.
7127 B<d> [I<line>] Delete the breakpoint for I<line>.
7128 B<D> Delete all breakpoints.
7129 B<a> [I<line>] I<command>
7130 Set an action to be done before the I<line> is executed;
7131 I<line> defaults to the current execution line.
7132 Sequence is: check for breakpoint/watchpoint, print line
7133 if necessary, do action, prompt user if necessary,
7135 B<a> [I<line>] Delete the action for I<line>.
7136 B<A> Delete all actions.
7137 B<W> I<expr> Add a global watch-expression.
7138 B<W> Delete all watch-expressions.
7139 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7140 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7141 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7142 B<x> I<expr> Evals expression in list context, dumps the result.
7143 B<m> I<expr> Evals expression in list context, prints methods callable
7144 on the first element of the result.
7145 B<m> I<class> Prints methods callable via the given class.
7147 B<<> ? List Perl commands to run before each prompt.
7148 B<<> I<expr> Define Perl command to run before each prompt.
7149 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7150 B<>> ? List Perl commands to run after each prompt.
7151 B<>> I<expr> Define Perl command to run after each prompt.
7152 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7153 B<{> I<db_command> Define debugger command to run before each prompt.
7154 B<{> ? List debugger commands to run before each prompt.
7155 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7156 B<$prc> I<number> Redo a previous command (default previous command).
7157 B<$prc> I<-number> Redo number'th-to-last command.
7158 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7159 See 'B<O> I<recallCommand>' too.
7160 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7165 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7167 See 'B<O> I<shellBang>' too.
7168 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7169 B<H> I<-number> Display last number commands (default all).
7170 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7171 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7172 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7173 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7174 I<command> Execute as a perl statement in current package.
7175 B<v> Show versions of loaded modules.
7176 B<R> Pure-man-restart of debugger, some of debugger state
7177 and command-line options may be lost.
7178 Currently the following settings are preserved:
7179 history, breakpoints and actions, debugger B<O>ptions
7180 and the following command-line options: I<-w>, I<-I>, I<-e>.
7182 B<O> [I<opt>] ... Set boolean option to true
7183 B<O> [I<opt>B<?>] Query options
7184 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7185 Set options. Use quotes in spaces in value.
7186 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7187 I<pager> program for output of \"|cmd\";
7188 I<tkRunning> run Tk while prompting (with ReadLine);
7189 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7190 I<inhibit_exit> Allows stepping off the end of the script.
7191 I<ImmediateStop> Debugger should stop as early as possible.
7192 I<RemotePort> Remote hostname:port for remote debugging
7193 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7194 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7195 I<compactDump>, I<veryCompact> change style of array and hash dump;
7196 I<globPrint> whether to print contents of globs;
7197 I<DumpDBFiles> dump arrays holding debugged files;
7198 I<DumpPackages> dump symbol tables of packages;
7199 I<DumpReused> dump contents of \"reused\" addresses;
7200 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7201 I<bareStringify> Do not print the overload-stringified value;
7202 Other options include:
7203 I<PrintRet> affects printing of return value after B<r> command,
7204 I<frame> affects printing messages on subroutine entry/exit.
7205 I<AutoTrace> affects printing messages on possible breaking points.
7206 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7207 I<ornaments> affects screen appearance of the command line.
7208 I<CreateTTY> bits control attempts to create a new TTY on events:
7209 1: on fork() 2: debugger is started inside debugger
7211 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7212 You can put additional initialization options I<TTY>, I<noTTY>,
7213 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7214 `B<R>' after you set them).
7216 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7217 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7218 B<h h> Summary of debugger commands.
7219 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7220 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7221 Set B<\$DB::doccmd> to change viewer.
7223 Type `|h' for a paged display if this was too hard to read.
7225 "; # Fix balance of vi % matching: }}}}
7227 # note: tabs in the following section are not-so-helpful
7228 $pre580_summary = <<"END_SUM";
7229 I<List/search source lines:> I<Control script execution:>
7230 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7231 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7232 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
7233 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7234 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7235 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
7236 I<Debugger controls:> B<L> List break/watch/actions
7237 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7238 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7239 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
7240 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7241 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
7242 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
7243 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7244 B<q> or B<^D> Quit B<R> Attempt a restart
7245 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7246 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7247 B<p> I<expr> Print expression (uses script's current package).
7248 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7249 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7250 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
7251 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7252 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7255 # ')}}; # Fix balance of vi % matching
7257 } ## end sub sethelp
7259 =head2 C<print_help()>
7261 Most of what C<print_help> does is just text formatting. It finds the
7262 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
7263 terminal control characters to simulate them (courtesy of
7264 <Term::ReadLine::TermCap>).
7271 # Restore proper alignment destroyed by eeevil I<> and B<>
7272 # ornaments: A pox on both their houses!
7274 # A help command will have everything up to and including
7275 # the first tab sequence padded into a field 16 (or if indented 20)
7276 # wide. If it's wider than that, an extra space will be added.
7278 ^ # only matters at start of line
7279 ( \040{4} | \t )* # some subcommands are indented
7280 ( < ? # so <CR> works
7281 [BI] < [^\t\n] + ) # find an eeevil ornament
7282 ( \t+ ) # original separation, discarded
7283 ( .* ) # this will now start (no earlier) than
7286 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
7287 my $clean = $command;
7288 $clean =~ s/[BI]<([^>]*)>/$1/g;
7290 # replace with this whole string:
7291 ($leadwhite ? " " x 4 : "")
7293 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
7298 s{ # handle bold ornaments
7299 B < ( [^>] + | > ) >
7301 $Term::ReadLine::TermCap::rl_term_set[2]
7303 . $Term::ReadLine::TermCap::rl_term_set[3]
7306 s{ # handle italic ornaments
7307 I < ( [^>] + | > ) >
7309 $Term::ReadLine::TermCap::rl_term_set[0]
7311 . $Term::ReadLine::TermCap::rl_term_set[1]
7316 } ## end sub print_help
7320 This routine does a lot of gyrations to be sure that the pager is C<less>.
7321 It checks for C<less> masquerading as C<more> and records the result in
7322 C<$ENV{LESS}> so we don't have to go through doing the stats again.
7328 # We already know if this is set.
7329 return if defined $ENV{LESS} && $ENV{LESS} =~ /r/;
7331 # Pager is less for sure.
7332 my $is_less = $pager =~ /\bless\b/;
7333 if ( $pager =~ /\bmore\b/ ) {
7335 # Nope, set to more. See what's out there.
7336 my @st_more = stat('/usr/bin/more');
7337 my @st_less = stat('/usr/bin/less');
7339 # is it really less, pretending to be more?
7342 && $st_more[0] == $st_less[0]
7343 && $st_more[1] == $st_less[1];
7344 } ## end if ($pager =~ /\bmore\b/)
7346 # changes environment!
7347 # 'r' added so we don't do (slow) stats again.
7348 $ENV{LESS} .= 'r' if $is_less;
7349 } ## end sub fix_less
7351 =head1 DIE AND WARN MANAGEMENT
7355 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
7356 to debug a debugger problem.
7358 It does its best to report the error that occurred, and then forces the
7359 program, debugger, and everything to die.
7365 # No entry/exit messages.
7368 # No return value prints.
7371 # set the abort signal handling to the default (just terminate).
7372 $SIG{'ABRT'} = 'DEFAULT';
7374 # If we enter the signal handler recursively, kill myself with an
7375 # abort signal (so we just terminate).
7376 kill 'ABRT', $$ if $panic++;
7378 # If we can show detailed info, do so.
7379 if ( defined &Carp::longmess ) {
7381 # Don't recursively enter the warn handler, since we're carping.
7382 local $SIG{__WARN__} = '';
7384 # Skip two levels before reporting traceback: we're skipping
7385 # mydie and confess.
7386 local $Carp::CarpLevel = 2; # mydie + confess
7388 # Tell us all about it.
7389 &warn( Carp::longmess("Signal @_") );
7392 # No Carp. Tell us about the signal as best we can.
7395 print $DB::OUT "Got signal @_\n";
7400 } ## end sub diesignal
7404 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
7405 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
7411 # No entry/exit trace.
7414 # No return value printing.
7417 # Turn off warn and die handling to prevent recursive entries to this
7419 local $SIG{__WARN__} = '';
7420 local $SIG{__DIE__} = '';
7422 # Load Carp if we can. If $^S is false (current thing being compiled isn't
7423 # done yet), we may not be able to do a require.
7424 eval { require Carp }
7425 if defined $^S; # If error/warning during compilation,
7426 # require may be broken.
7428 # Use the core warn() unless Carp loaded OK.
7430 "\nCannot print stack trace, load with -MCarp option to see stack" ),
7432 unless defined &Carp::longmess;
7434 # Save the current values of $single and $trace, and then turn them off.
7435 my ( $mysingle, $mytrace ) = ( $single, $trace );
7439 # We can call Carp::longmess without its being "debugged" (which we
7440 # don't want - we just want to use it!). Capture this for later.
7441 my $mess = Carp::longmess(@_);
7443 # Restore $single and $trace to their original values.
7444 ( $single, $trace ) = ( $mysingle, $mytrace );
7446 # Use the debugger's own special way of printing warnings to print
7447 # the stack trace message.
7453 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
7454 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
7455 single stepping and tracing during the call to C<Carp::longmess> to avoid
7456 debugging it - we just want to use it.
7458 If C<dieLevel> is zero, we let the program being debugged handle the
7459 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
7460 the debugger takes over all exception handling, printing a backtrace and
7461 displaying the exception via its C<dbwarn()> routine.
7468 local $SIG{__DIE__} = '';
7469 local $SIG{__WARN__} = '';
7473 if ( $dieLevel > 2 ) {
7474 local $SIG{__WARN__} = \&dbwarn;
7475 &warn(@_); # Yell no matter what
7478 if ( $dieLevel < 2 ) {
7479 die @_ if $^S; # in eval propagate
7482 # The code used to check $^S to see if compiliation of the current thing
7483 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
7484 eval { require Carp };
7487 "\nCannot print stack trace, load with -MCarp option to see stack" )
7488 unless defined &Carp::longmess;
7490 # We do not want to debug this chunk (automatic disabling works
7491 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
7492 # get the stack trace from Carp::longmess (if possible), restore $signal
7493 # and $trace, and then die with the stack trace.
7494 my ( $mysingle, $mytrace ) = ( $single, $trace );
7500 package Carp; # Do not include us in the list
7501 eval { $mess = Carp::longmess(@_); };
7503 ( $single, $trace ) = ( $mysingle, $mytrace );
7507 =head2 C<warnlevel()>
7509 Set the C<$DB::warnLevel> variable that stores the value of the
7510 C<warnLevel> option. Calling C<warnLevel()> with a positive value
7511 results in the debugger taking over all warning handlers. Setting
7512 C<warnLevel> to zero leaves any warning handlers set up by the program
7513 being debugged in place.
7519 $prevwarn = $SIG{__WARN__} unless $warnLevel;
7522 $SIG{__WARN__} = \&DB::dbwarn;
7525 $SIG{__WARN__} = $prevwarn;
7529 } ## end sub warnLevel
7533 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
7534 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
7535 zero lets you use your own C<die()> handler.
7542 $prevdie = $SIG{__DIE__} unless $dieLevel;
7546 # Always set it to dbdie() for non-zero values.
7547 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
7549 # No longer exists, so don't try to use it.
7550 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
7552 # If we've finished initialization, mention that stack dumps
7553 # are enabled, If dieLevel is 1, we won't stack dump if we die
7555 print $OUT "Stack dump during die enabled",
7556 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
7559 # XXX This is probably obsolete, given that diehard() is gone.
7560 print $OUT "Dump printed too.\n" if $dieLevel > 2;
7561 } ## end if ($dieLevel)
7563 # Put the old one back if there was one.
7565 $SIG{__DIE__} = $prevdie;
7566 print $OUT "Default die handler restored.\n";
7570 } ## end sub dieLevel
7572 =head2 C<signalLevel>
7574 Number three in a series: set C<signalLevel> to zero to keep your own
7575 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
7576 takes over and handles them with C<DB::diesignal()>.
7582 $prevsegv = $SIG{SEGV} unless $signalLevel;
7583 $prevbus = $SIG{BUS} unless $signalLevel;
7584 $signalLevel = shift;
7586 $SIG{SEGV} = \&DB::diesignal;
7587 $SIG{BUS} = \&DB::diesignal;
7590 $SIG{SEGV} = $prevsegv;
7591 $SIG{BUS} = $prevbus;
7595 } ## end sub signalLevel
7597 =head1 SUBROUTINE DECODING SUPPORT
7599 These subroutines are used during the C<x> and C<X> commands to try to
7600 produce as much information as possible about a code reference. They use
7601 L<Devel::Peek> to try to find the glob in which this code reference lives
7602 (if it does) - this allows us to actually code references which correspond
7603 to named subroutines (including those aliased via glob assignment).
7605 =head2 C<CvGV_name()>
7607 Wrapper for X<CvGV_name_or_bust>; tries to get the name of a reference
7608 via that routine. If this fails, return the reference again (when the
7609 reference is stringified, it'll come out as "SOMETHING(0X...)").
7615 my $name = CvGV_name_or_bust($in);
7616 defined $name ? $name : $in;
7619 =head2 C<CvGV_name_or_bust> I<coderef>
7621 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
7622 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
7623 find a glob for this ref.
7625 Returns "I<package>::I<glob name>" if the code ref is found in a glob.
7629 sub CvGV_name_or_bust {
7631 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
7632 return unless ref $in;
7633 $in = \&$in; # Hard reference...
7634 eval { require Devel::Peek; 1 } or return;
7635 my $gv = Devel::Peek::CvGV($in) or return;
7636 *$gv{PACKAGE} . '::' . *$gv{NAME};
7637 } ## end sub CvGV_name_or_bust
7641 A utility routine used in various places; finds the file where a subroutine
7642 was defined, and returns that filename and a line-number range.
7644 Tries to use X<@sub> first; if it can't find it there, it tries building a
7645 reference to the subroutine and uses X<CvGV_name_or_bust> to locate it,
7646 loading it into X<@sub> as a side effect (XXX I think). If it can't find it
7647 this way, it brute-force searches X<%sub>, checking for identical references.
7654 return unless defined &$subr;
7655 my $name = CvGV_name_or_bust($subr);
7657 $data = $sub{$name} if defined $name;
7658 return $data if defined $data;
7661 $subr = \&$subr; # Hard reference
7664 $s = $_, last if $subr eq \&$_;
7668 } ## end sub find_sub
7672 A subroutine that uses the utility function X<methods_via> to find all the
7673 methods in the class corresponding to the current reference and in
7680 # Figure out the class - either this is the class or it's a reference
7681 # to something blessed into that class.
7683 $class = ref $class if ref $class;
7687 # Show the methods that this class has.
7688 methods_via( $class, '', 1 );
7690 # Show the methods that UNIVERSAL has.
7691 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
7692 } ## end sub methods
7694 =head2 C<methods_via($class, $prefix, $crawl_upward)>
7696 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
7697 all the parent class methods. C<$class> is the name of the next class to
7698 try; C<$prefix> is the message prefix, which gets built up as we go up the
7699 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
7700 higher in the C<@ISA> tree, 0 if we should stop.
7706 # If we've processed this class already, just quit.
7708 return if $seen{$class}++;
7710 # This is a package that is contributing the methods we're about to print.
7712 my $prepend = $prefix ? "via $prefix: " : '';
7717 # Keep if this is a defined subroutine in this class.
7718 grep { defined &{ ${"${class}::"}{$_} } }
7720 # Extract from all the symbols in this class.
7721 sort keys %{"${class}::"}
7725 # If we printed this already, skip it.
7726 next if $seen{$name}++;
7728 # Print the new method name.
7731 print $DB::OUT "$prepend$name\n";
7732 } ## end for $name (grep { defined...
7734 # If the $crawl_upward argument is false, just quit here.
7735 return unless shift;
7737 # $crawl_upward true: keep going up the tree.
7738 # Find all the classes this one is a subclass of.
7739 for $name ( @{"${class}::ISA"} ) {
7741 # Set up the new prefix.
7742 $prepend = $prefix ? $prefix . " -> $name" : $name;
7744 # Crawl up the tree and keep trying to crawl up.
7745 methods_via( $name, $prepend, 1 );
7747 } ## end sub methods_via
7749 =head2 C<setman> - figure out which command to use to show documentation
7751 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
7756 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|MacOS|NetWare)\z/s
7757 ? "man" # O Happy Day!
7758 : "perldoc"; # Alas, poor unfortunates
7761 =head2 C<runman> - run the appropriate command to show documentation
7763 Accepts a man page name; runs the appropriate command to display it (set up
7764 during debugger initialization). Uses C<DB::system> to avoid mucking up the
7765 program's STDIN and STDOUT.
7772 &system("$doccmd $doccmd");
7776 # this way user can override, like with $doccmd="man -Mwhatever"
7777 # or even just "man " to disable the path check.
7778 unless ( $doccmd eq 'man' ) {
7779 &system("$doccmd $page");
7783 $page = 'perl' if lc($page) eq 'help';
7786 my $man1dir = $Config::Config{'man1dir'};
7787 my $man3dir = $Config::Config{'man3dir'};
7788 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
7790 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
7791 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
7792 chop $manpath if $manpath;
7794 # harmless if missing, I figure
7795 my $oldpath = $ENV{MANPATH};
7796 $ENV{MANPATH} = $manpath if $manpath;
7797 my $nopathopt = $^O =~ /dunno what goes here/;
7802 # I just *know* there are men without -M
7803 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
7808 unless ( $page =~ /^perl\w/ ) {
7809 # do it this way because its easier to slurp in to keep up to date - clunky though.
7948 if (grep { $page eq $_ } @pods) {
7950 CORE::system( $doccmd,
7951 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
7953 } ## end if (grep { $page eq $_...
7954 } ## end unless ($page =~ /^perl\w/)
7955 } ## end if (CORE::system($doccmd...
7956 if ( defined $oldpath ) {
7957 $ENV{MANPATH} = $manpath;
7960 delete $ENV{MANPATH};
7964 #use Carp; # This did break, left for debugging
7966 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
7968 Because of the way the debugger interface to the Perl core is designed, any
7969 debugger package globals that C<DB::sub()> requires have to be defined before
7970 any subroutines can be called. These are defined in the second C<BEGIN> block.
7972 This block sets things up so that (basically) the world is sane
7973 before the debugger starts executing. We set up various variables that the
7974 debugger has to have set up before the Perl core starts running:
7978 =item * The debugger's own filehandles (copies of STD and STDOUT for now).
7980 =item * Characters for shell escapes, the recall command, and the history command.
7982 =item * The maximum recursion depth.
7984 =item * The size of a C<w> command's window.
7986 =item * The before-this-line context to be printed in a C<v> (view a window around this line) command.
7988 =item * The fact that we're not in a sub at all right now.
7990 =item * The default SIGINT handler for the debugger.
7992 =item * The appropriate value of the flag in C<$^D> that says the debugger is running
7994 =item * The current debugger recursion level
7996 =item * The list of postponed (XXX define) items and the C<$single> stack
7998 =item * That we want no return values and no subroutine entry/exit trace.
8004 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
8006 BEGIN { # This does not compile, alas. (XXX eh?)
8007 $IN = \*STDIN; # For bugs before DB::OUT has been opened
8008 $OUT = \*STDERR; # For errors before DB::OUT has been opened
8010 # Define characters used by command parsing.
8011 $sh = '!'; # Shell escape (does not work)
8012 $rc = ','; # Recall command (does not work)
8013 @hist = ('?'); # Show history (does not work)
8014 @truehist = (); # Can be saved for replay (per session)
8016 # This defines the point at which you get the 'deep recursion'
8017 # warning. It MUST be defined or the debugger will not load.
8020 # Number of lines around the current one that are shown in the
8024 # How much before-the-current-line context the 'v' command should
8025 # use in calculating the start of the window it will display.
8028 # We're not in any sub yet, but we need this to be a defined value.
8031 # Set up the debugger's interrupt handler. It simply sets a flag
8032 # ($signal) that DB::DB() will check before each command is executed.
8033 $SIG{INT} = \&DB::catch;
8035 # The following lines supposedly, if uncommented, allow the debugger to
8036 # debug itself. Perhaps we can try that someday.
8037 # This may be enabled to debug debugger:
8038 #$warnLevel = 1 unless defined $warnLevel;
8039 #$dieLevel = 1 unless defined $dieLevel;
8040 #$signalLevel = 1 unless defined $signalLevel;
8042 # This is the flag that says "a debugger is running, please call
8043 # DB::DB and DB::sub". We will turn it on forcibly before we try to
8044 # execute anything in the user's context, because we always want to
8046 $db_stop = 0; # Compiler warning ...
8047 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
8049 # This variable records how many levels we're nested in debugging. Used
8050 # Used in the debugger prompt, and in determining whether it's all over or
8052 $level = 0; # Level of recursive debugging
8054 # "Triggers bug (?) in perl if we postpone this until runtime."
8055 # XXX No details on this yet, or whether we should fix the bug instead
8056 # of work around it. Stay tuned.
8057 @postponed = @stack = (0);
8059 # Used to track the current stack depth using the auto-stacked-variable
8061 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
8063 # Don't print return values on exiting a subroutine.
8066 # No extry/exit tracing.
8071 BEGIN { $^W = $ini_warn; } # Switch warnings back
8073 =head1 READLINE SUPPORT - COMPLETION FUNCTION
8077 C<readline> support - adds command completion to basic C<readline>.
8079 Returns a list of possible completions to C<readline> when invoked. C<readline>
8080 will print the longest common substring following the text already entered.
8082 If there is only a single possible completion, C<readline> will use it in full.
8084 This code uses C<map> and C<grep> heavily to create lists of possible
8085 completion. Think LISP in this section.
8091 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
8092 # $text is the text to be completed.
8093 # $line is the incoming line typed by the user.
8094 # $start is the start of the text to be completed in the incoming line.
8095 my ( $text, $line, $start ) = @_;
8097 # Save the initial text.
8098 # The search pattern is current package, ::, extract the next qualifier
8099 # Prefix and pack are set to undef.
8100 my ( $itext, $search, $prefix, $pack ) =
8101 ( $text, "^\Q${'package'}::\E([^:]+)\$" );
8103 =head3 C<b postpone|compile>
8107 =item * Find all the subroutines that might match in this package
8109 =item * Add "postpone", "load", and "compile" as possibles (we may be completing the keyword itself
8111 =item * Include all the rest of the subs that are known
8113 =item * C<grep> out the ones that match the text we have so far
8115 =item * Return this as the list of possible completions
8121 return sort grep /^\Q$text/, ( keys %sub ),
8122 qw(postpone load compile), # subroutines
8123 ( map { /$search/ ? ($1) : () } keys %sub )
8124 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
8128 Get all the possible files from @INC as it currently stands and
8129 select the ones that match the text so far.
8133 return sort grep /^\Q$text/, values %INC # files
8134 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
8136 =head3 C<V> (list variable) and C<m> (list modules)
8138 There are two entry points for these commands:
8140 =head4 Unqualified package names
8142 Get the top-level packages and grab everything that matches the text
8143 so far. For each match, recursively complete the partial packages to
8144 get all possible matching packages. Return this sorted list.
8148 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8149 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
8150 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
8152 =head4 Qualified package names
8154 Take a partially-qualified package and find all subpackages for it
8155 by getting all the subpackages for the package so far, matching all
8156 the subpackages against the text, and discarding all of them which
8157 start with 'main::'. Return this list.
8161 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8162 grep !/^main::/, grep /^\Q$text/,
8163 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () } keys %{ $prefix . '::' }
8164 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
8165 and $text =~ /^(.*[^:])::?(\w*)$/
8168 =head3 C<f> - switch files
8170 Here, we want to get a fully-qualified filename for the C<f> command.
8175 =item 1. The original source file itself
8177 =item 2. A file from C<@INC>
8179 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
8185 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
8186 # We might possibly want to switch to an eval (which has a "filename"
8187 # like '(eval 9)'), so we may need to clean up the completion text
8188 # before proceeding.
8189 $prefix = length($1) - length($text);
8194 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
8195 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
8196 out of C<%main::>, add the initial source file, and extract the ones that
8197 match the completion text so far.
8202 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
8204 } ## end if ($line =~ /^\|*f\s+(.*)/)
8206 =head3 Subroutine name completion
8208 We look through all of the defined subs (the keys of C<%sub>) and
8209 return both all the possible matches to the subroutine name plus
8210 all the matches qualified to the current package.
8214 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
8215 $text = substr $text, 1;
8217 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
8219 map { /$search/ ? ($1) : () }
8222 } ## end if ((substr $text, 0, ...
8224 =head3 Scalar, array, and hash completion: partially qualified package
8226 Much like the above, except we have to do a little more cleanup:
8230 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
8236 =item * Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
8240 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
8244 =item * Figure out the prefix vs. what needs completing.
8248 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
8253 =item * Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
8257 my @out = map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
8262 =item * 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.
8266 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8267 return db_complete( $out[0], $line, $start );
8270 # Return the list of possibles.
8273 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
8279 =head3 Symbol completion: current package or package C<main>.
8283 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
8289 =item * If it's C<main>, delete main to just get C<::> leading.
8293 $pack = ( $package eq 'main' ? '' : $package ) . '::';
8297 =item * We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
8301 $prefix = substr $text, 0, 1;
8302 $text = substr $text, 1;
8306 =item * If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
8310 my @out = map "$prefix$_", grep /^\Q$text/,
8311 ( grep /^_?[a-zA-Z]/, keys %$pack ),
8312 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
8314 =item * If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
8320 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8321 return db_complete( $out[0], $line, $start );
8324 # Return the list of possibles.
8326 } ## end if ($text =~ /^[\$@%]/)
8330 We use C<option_val()> to look up the current value of the option. If there's
8331 only a single value, we complete the command in such a way that it is a
8332 complete command for setting the option in question. If there are multiple
8333 possible values, we generate a command consisting of the option plus a trailing
8334 question mark, which, if executed, will list the current value of the option.
8338 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
8339 { # Options after space
8340 # We look for the text to be matched in the list of possible options,
8341 # and fetch the current value.
8342 my @out = grep /^\Q$text/, @options;
8343 my $val = option_val( $out[0], undef );
8345 # Set up a 'query option's value' command.
8347 if ( not defined $val or $val =~ /[\n\r]/ ) {
8349 # There's really nothing else we can do.
8352 # We have a value. Create a proper option-setting command.
8353 elsif ( $val =~ /\s/ ) {
8355 # XXX This may be an extraneous variable.
8358 # We'll want to quote the string (because of the embedded
8359 # whtespace), but we want to make sure we don't end up with
8360 # mismatched quote characters. We try several possibilities.
8361 foreach $l ( split //, qq/\"\'\#\|/ ) {
8363 # If we didn't find this quote character in the value,
8364 # quote it using this quote character.
8365 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
8367 } ## end elsif ($val =~ /\s/)
8369 # Don't need any quotes.
8374 # If there were multiple possible values, return '? ', which
8375 # makes the command into a query command. If there was just one,
8376 # have readline append that.
8377 $rl_attribs->{completer_terminator_character} =
8378 ( @out == 1 ? $out : '? ' );
8380 # Return list of possibilities.
8382 } ## end if ((substr $line, 0, ...
8384 =head3 Filename completion
8386 For entering filenames. We simply call C<readline>'s C<filename_list()>
8387 method with the completion text to get the possible completions.
8391 return $term->filename_list($text); # filenames
8393 } ## end sub db_complete
8395 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
8397 Functions that possibly ought to be somewhere else.
8407 print $OUT "Use `q' to quit or `R' to restart. `h q' for details.\n";
8412 If we have $ini_pids, save it in the environment; else remove it from the
8413 environment. Used by the C<R> (restart) command.
8418 if ( defined($ini_pids) ) {
8419 $ENV{PERLDB_PIDS} = $ini_pids;
8422 delete( $ENV{PERLDB_PIDS} );
8424 } ## end sub clean_ENV
8426 # PERLDBf_... flag names from perl.h
8427 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
8430 %DollarCaretP_flags = (
8431 PERLDBf_SUB => 0x01, # Debug sub enter/exit
8432 PERLDBf_LINE => 0x02, # Keep line #
8433 PERLDBf_NOOPT => 0x04, # Switch off optimizations
8434 PERLDBf_INTER => 0x08, # Preserve more data
8435 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
8436 PERLDBf_SINGLE => 0x20, # Start with single-step on
8437 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
8438 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
8439 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
8440 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
8441 PERLDBf_ASSERTION => 0x400, # Debug assertion subs enter/exit
8442 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO, _ASSERTION
8445 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
8448 sub parse_DollarCaretP_flags {
8453 foreach my $f ( split /\s*\|\s*/, $flags ) {
8455 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
8458 elsif ( $f =~ /^(\d+)$/ ) {
8461 elsif ( $f =~ /^DEFAULT$/i ) {
8462 $value = $DollarCaretP_flags{PERLDB_ALL};
8465 $f =~ /^(?:PERLDBf_)?(.*)$/i;
8466 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
8467 unless ( defined $value ) {
8469 "Unrecognized \$^P flag '$f'!\n",
8470 "Acceptable flags are: "
8471 . join( ', ', sort keys %DollarCaretP_flags ),
8472 ", and hexadecimal and decimal numbers.\n"
8482 sub expand_DollarCaretP_flags {
8483 my $DollarCaretP = shift;
8486 my $n = ( 1 << $_ );
8487 ( $DollarCaretP & $n )
8488 ? ( $DollarCaretP_flags_r{$n}
8489 || sprintf( '0x%x', $n ) )
8493 return @bits ? join( '|', @bits ) : 0;
8498 Rerun the current session to:
8500 rerun current position
8502 rerun 4 command number 4
8504 rerun -4 current command minus 4 (go back 4 steps)
8506 Whether this always makes sense, in the current context is unknowable, and is
8507 in part left as a useful exersize for the reader. This sub returns the
8508 appropriate arguments to rerun the current session.
8515 pop(@truehist); # strim
8516 unless (defined $truehist[$i]) {
8517 print "Unable to return to non-existent command: $i\n";
8519 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
8520 my @temp = @truehist; # store
8521 push(@DB::typeahead, @truehist); # saved
8522 @truehist = @hist = (); # flush
8523 @args = &restart(); # setup
8524 &get_list("PERLDB_HIST"); # clean
8525 &set_list("PERLDB_HIST", @temp); # reset
8532 Restarting the debugger is a complex operation that occurs in several phases.
8533 First, we try to reconstruct the command line that was used to invoke Perl
8539 # I may not be able to resurrect you, but here goes ...
8541 "Warning: some settings and command-line options may be lost!\n";
8542 my ( @script, @flags, $cl );
8544 # If warn was on before, turn it on again.
8545 push @flags, '-w' if $ini_warn;
8546 if ( $ini_assertion and @{^ASSERTING} ) {
8548 ( map { /\:\^\(\?\:(.*)\)\$\)/ ? "-A$1" : "-A$_" }
8552 # Rebuild the -I flags that were on the initial
8555 push @flags, '-I', $_;
8558 # Turn on taint if it was on before.
8559 push @flags, '-T' if ${^TAINT};
8561 # Arrange for setting the old INC:
8562 # Save the current @init_INC in the environment.
8563 set_list( "PERLDB_INC", @ini_INC );
8565 # If this was a perl one-liner, go to the "file"
8566 # corresponding to the one-liner read all the lines
8567 # out of it (except for the first one, which is going
8568 # to be added back on again when 'perl -d' runs: that's
8569 # the 'require perl5db.pl;' line), and add them back on
8570 # to the command line to be executed.
8572 for ( 1 .. $#{'::_<-e'} ) { # The first line is PERL5DB
8573 chomp( $cl = ${'::_<-e'}[$_] );
8574 push @script, '-e', $cl;
8576 } ## end if ($0 eq '-e')
8578 # Otherwise we just reuse the original name we had
8586 After the command line has been reconstructed, the next step is to save
8587 the debugger's status in environment variables. The C<DB::set_list> routine
8588 is used to save aggregate variables (both hashes and arrays); scalars are
8589 just popped into environment variables directly.
8593 # If the terminal supported history, grab it and
8594 # save that in the environment.
8595 set_list( "PERLDB_HIST",
8596 $term->Features->{getHistory}
8600 # Find all the files that were visited during this
8601 # session (i.e., the debugger had magic hashes
8602 # corresponding to them) and stick them in the environment.
8603 my @had_breakpoints = keys %had_breakpoints;
8604 set_list( "PERLDB_VISITED", @had_breakpoints );
8606 # Save the debugger options we chose.
8607 set_list( "PERLDB_OPT", %option );
8608 # set_list( "PERLDB_OPT", options2remember() );
8610 # Save the break-on-loads.
8611 set_list( "PERLDB_ON_LOAD", %break_on_load );
8615 The most complex part of this is the saving of all of the breakpoints. They
8616 can live in an awful lot of places, and we have to go through all of them,
8617 find the breakpoints, and then save them in the appropriate environment
8618 variable via C<DB::set_list>.
8622 # Go through all the breakpoints and make sure they're
8625 for ( 0 .. $#had_breakpoints ) {
8627 # We were in this file.
8628 my $file = $had_breakpoints[$_];
8630 # Grab that file's magic line hash.
8631 *dbline = $main::{ '_<' . $file };
8633 # Skip out if it doesn't exist, or if the breakpoint
8634 # is in a postponed file (we'll do postponed ones
8636 next unless %dbline or $postponed_file{$file};
8638 # In an eval. This is a little harder, so we'll
8639 # do more processing on that below.
8640 ( push @hard, $file ), next
8641 if $file =~ /^\(\w*eval/;
8643 # XXX I have no idea what this is doing. Yet.
8645 @add = %{ $postponed_file{$file} }
8646 if $postponed_file{$file};
8648 # Save the list of all the breakpoints for this file.
8649 set_list( "PERLDB_FILE_$_", %dbline, @add );
8650 } ## end for (0 .. $#had_breakpoints)
8652 # The breakpoint was inside an eval. This is a little
8653 # more difficult. XXX and I don't understand it.
8655 # Get over to the eval in question.
8656 *dbline = $main::{ '_<' . $_ };
8657 my ( $quoted, $sub, %subs, $line ) = quotemeta $_;
8658 for $sub ( keys %sub ) {
8659 next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/;
8660 $subs{$sub} = [ $1, $2 ];
8664 "No subroutines in $_, ignoring breakpoints.\n";
8667 LINES: for $line ( keys %dbline ) {
8669 # One breakpoint per sub only:
8670 my ( $offset, $sub, $found );
8671 SUBS: for $sub ( keys %subs ) {
8674 $line # Not after the subroutine
8676 not defined $offset # Not caught
8682 $offset = $line - $subs{$sub}->[0];
8683 $offset = "+$offset", last SUBS
8685 } ## end if ($subs{$sub}->[1] >=...
8686 } ## end for $sub (keys %subs)
8687 if ( defined $offset ) {
8688 $postponed{$found} =
8689 "break $offset if $dbline{$line}";
8693 "Breakpoint in $_:$line ignored: after all the subroutines.\n";
8695 } ## end for $line (keys %dbline)
8696 } ## end for (@hard)
8698 # Save the other things that don't need to be
8700 set_list( "PERLDB_POSTPONE", %postponed );
8701 set_list( "PERLDB_PRETYPE", @$pretype );
8702 set_list( "PERLDB_PRE", @$pre );
8703 set_list( "PERLDB_POST", @$post );
8704 set_list( "PERLDB_TYPEAHEAD", @typeahead );
8706 # We are oficially restarting.
8707 $ENV{PERLDB_RESTART} = 1;
8709 # We are junking all child debuggers.
8710 delete $ENV{PERLDB_PIDS}; # Restore ini state
8712 # Set this back to the initial pid.
8713 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
8717 After all the debugger status has been saved, we take the command we built up
8718 and then return it, so we can C<exec()> it. The debugger will spot the
8719 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
8720 from the environment.
8724 # And run Perl again. Add the "-d" flag, all the
8725 # flags we built up, the script (whether a one-liner
8726 # or a file), add on the -emacs flag for a slave editor,
8727 # and then the old arguments.
8729 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
8733 =head1 END PROCESSING - THE C<END> BLOCK
8735 Come here at the very end of processing. We want to go into a
8736 loop where we allow the user to enter commands and interact with the
8737 debugger, but we don't want anything else to execute.
8739 First we set the C<$finished> variable, so that some commands that
8740 shouldn't be run after the end of program quit working.
8742 We then figure out whether we're truly done (as in the user entered a C<q>
8743 command, or we finished execution while running nonstop). If we aren't,
8744 we set C<$single> to 1 (causing the debugger to get control again).
8746 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...">
8747 message and returns control to the debugger. Repeat.
8749 When the user finally enters a C<q> command, C<$fall_off_end> is set to
8750 1 and the C<END> block simply exits with C<$single> set to 0 (don't
8751 break, run to completion.).
8756 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
8757 $fall_off_end = 1 unless $inhibit_exit;
8759 # Do not stop in at_exit() and destructors on exit:
8760 $DB::single = !$fall_off_end && !$runnonstop;
8761 DB::fake::at_exit() unless $fall_off_end or $runnonstop;
8764 =head1 PRE-5.8 COMMANDS
8766 Some of the commands changed function quite a bit in the 5.8 command
8767 realignment, so much so that the old code had to be replaced completely.
8768 Because we wanted to retain the option of being able to go back to the
8769 former command set, we moved the old code off to this section.
8771 There's an awful lot of duplicated code here. We've duplicated the
8772 comments to keep things clear.
8776 Does nothing. Used to 'turn off' commands.
8780 sub cmd_pre580_null {
8785 =head2 Old C<a> command.
8787 This version added actions if you supplied them, and deleted them
8796 # Argument supplied. Add the action.
8797 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
8799 # If the line isn't there, use the current line.
8803 # If there is an action ...
8806 # ... but the line isn't breakable, skip it.
8807 if ( $dbline[$i] == 0 ) {
8808 print $OUT "Line $i may not have an action.\n";
8812 # ... and the line is breakable:
8813 # Mark that there's an action in this file.
8814 $had_breakpoints{$filename} |= 2;
8816 # Delete any current action.
8817 $dbline{$i} =~ s/\0[^\0]*//;
8819 # Add the new action, continuing the line as needed.
8820 $dbline{$i} .= "\0" . action($j);
8822 } ## end if (length $j)
8824 # No action supplied.
8827 # Delete the action.
8828 $dbline{$i} =~ s/\0[^\0]*//;
8830 # Mark as having no break or action if nothing's left.
8831 delete $dbline{$i} if $dbline{$i} eq '';
8833 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
8834 } ## end sub cmd_pre580_a
8836 =head2 Old C<b> command
8848 if ( $cmd =~ /^load\b\s*(.*)/ ) {
8854 # b compile|postpone <some sub> [<condition>]
8855 # The interpreter actually traps this one for us; we just put the
8856 # necessary condition in the %postponed hash.
8857 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
8859 # Capture the condition if there is one. Make it true if none.
8860 my $cond = length $3 ? $3 : '1';
8862 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
8863 # if it was 'compile'.
8864 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
8866 # De-Perl4-ify the name - ' separators to ::.
8867 $subname =~ s/\'/::/g;
8869 # Qualify it into the current package unless it's already qualified.
8870 $subname = "${'package'}::" . $subname
8871 unless $subname =~ /::/;
8873 # Add main if it starts with ::.
8874 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
8876 # Save the break type for this sub.
8877 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
8878 } ## end elsif ($cmd =~ ...
8880 # b <sub name> [<condition>]
8881 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
8883 my $cond = length $2 ? $2 : '1';
8884 &cmd_b_sub( $subname, $cond );
8887 # b <line> [<condition>].
8888 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
8889 my $i = $1 || $dbline;
8890 my $cond = length $2 ? $2 : '1';
8891 &cmd_b_line( $i, $cond );
8893 } ## end sub cmd_pre580_b
8895 =head2 Old C<D> command.
8897 Delete all breakpoints unconditionally.
8904 if ( $cmd =~ /^\s*$/ ) {
8905 print $OUT "Deleting all breakpoints...\n";
8907 # %had_breakpoints lists every file that had at least one
8910 for $file ( keys %had_breakpoints ) {
8912 # Switch to the desired file temporarily.
8913 local *dbline = $main::{ '_<' . $file };
8918 # For all lines in this file ...
8919 for ( $i = 1 ; $i <= $max ; $i++ ) {
8921 # If there's a breakpoint or action on this line ...
8922 if ( defined $dbline{$i} ) {
8924 # ... remove the breakpoint.
8925 $dbline{$i} =~ s/^[^\0]+//;
8926 if ( $dbline{$i} =~ s/^\0?$// ) {
8928 # Remove the entry altogether if no action is there.
8931 } ## end if (defined $dbline{$i...
8932 } ## end for ($i = 1 ; $i <= $max...
8934 # If, after we turn off the "there were breakpoints in this file"
8935 # bit, the entry in %had_breakpoints for this file is zero,
8936 # we should remove this file from the hash.
8937 if ( not $had_breakpoints{$file} &= ~1 ) {
8938 delete $had_breakpoints{$file};
8940 } ## end for $file (keys %had_breakpoints)
8942 # Kill off all the other breakpoints that are waiting for files that
8943 # haven't been loaded yet.
8945 undef %postponed_file;
8946 undef %break_on_load;
8947 } ## end if ($cmd =~ /^\s*$/)
8948 } ## end sub cmd_pre580_D
8950 =head2 Old C<h> command
8952 Print help. Defaults to printing the long-form help; the 5.8 version
8953 prints the summary by default.
8961 # Print the *right* help, long format.
8962 if ( $cmd =~ /^\s*$/ ) {
8963 print_help($pre580_help);
8966 # 'h h' - explicitly-requested summary.
8967 elsif ( $cmd =~ /^h\s*/ ) {
8968 print_help($pre580_summary);
8971 # Find and print a command's help.
8972 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
8973 my $asked = $1; # for proper errmsg
8974 my $qasked = quotemeta($asked); # for searching
8975 # XXX: finds CR but not <CR>
8979 (?:[IB]<) # Optional markup
8980 $qasked # The command name
8987 ( # The command help:
8989 (?:[IB]<) # Optional markup
8990 $qasked # The command name
8991 ([\s\S]*?) # Lines starting with tabs
8995 ) # Line not starting with space
8996 # (Next command's help)
9000 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
9004 print_help("B<$asked> is not a debugger command.\n");
9006 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
9007 } ## end sub cmd_pre580_h
9009 =head2 Old C<W> command
9011 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
9019 # Delete all watch expressions.
9020 if ( $cmd =~ /^$/ ) {
9022 # No watching is going on.
9025 # Kill all the watch expressions and values.
9026 @to_watch = @old_watch = ();
9029 # Add a watch expression.
9030 elsif ( $cmd =~ /^(.*)/s ) {
9032 # add it to the list to be watched.
9035 # Get the current value of the expression.
9036 # Doesn't handle expressions returning list values!
9039 $val = ( defined $val ) ? "'$val'" : 'undef';
9042 push @old_watch, $val;
9044 # We're watching stuff.
9047 } ## end elsif ($cmd =~ /^(.*)/s)
9048 } ## end sub cmd_pre580_W
9050 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
9052 The debugger used to have a bunch of nearly-identical code to handle
9053 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
9054 C<cmd_prepost> unify all this into one set of code to handle the
9055 appropriate actions.
9057 =head2 C<cmd_pre590_prepost>
9059 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
9060 do something destructive. In pre 5.8 debuggers, the default action was to
9061 delete all the actions.
9065 sub cmd_pre590_prepost {
9067 my $line = shift || '*';
9070 return &cmd_prepost( $cmd, $line, $dbline );
9071 } ## end sub cmd_pre590_prepost
9073 =head2 C<cmd_prepost>
9075 Actually does all the handling foe C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
9076 Since the lists of actions are all held in arrays that are pointed to by
9077 references anyway, all we have to do is pick the right array reference and
9078 then use generic code to all, delete, or list actions.
9085 # No action supplied defaults to 'list'.
9086 my $line = shift || '?';
9088 # Figure out what to put in the prompt.
9091 # Make sure we have some array or another to address later.
9092 # This means that if ssome reason the tests fail, we won't be
9093 # trying to stash actions or delete them from the wrong place.
9096 # < - Perl code to run before prompt.
9097 if ( $cmd =~ /^\</o ) {
9098 $which = 'pre-perl';
9102 # > - Perl code to run after prompt.
9103 elsif ( $cmd =~ /^\>/o ) {
9104 $which = 'post-perl';
9108 # { - first check for properly-balanced braces.
9109 elsif ( $cmd =~ /^\{/o ) {
9110 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
9112 "$cmd is now a debugger command\nuse `;$cmd' if you mean Perl code\n";
9115 # Properly balanced. Pre-prompt debugger actions.
9117 $which = 'pre-debugger';
9120 } ## end elsif ( $cmd =~ /^\{/o )
9122 # Did we find something that makes sense?
9124 print $OUT "Confused by command: $cmd\n";
9131 if ( $line =~ /^\s*\?\s*$/o ) {
9134 # Nothing there. Complain.
9135 print $OUT "No $which actions.\n";
9139 # List the actions in the selected list.
9140 print $OUT "$which commands:\n";
9141 foreach my $action (@$aref) {
9142 print $OUT "\t$cmd -- $action\n";
9145 } ## end if ( $line =~ /^\s*\?\s*$/o)
9147 # Might be a delete.
9149 if ( length($cmd) == 1 ) {
9150 if ( $line =~ /^\s*\*\s*$/o ) {
9152 # It's a delete. Get rid of the old actions in the
9155 print $OUT "All $cmd actions cleared.\n";
9159 # Replace all the actions. (This is a <, >, or {).
9160 @$aref = action($line);
9162 } ## end if ( length($cmd) == 1)
9163 elsif ( length($cmd) == 2 ) {
9165 # Add the action to the line. (This is a <<, >>, or {{).
9166 push @$aref, action($line);
9170 # <<<, >>>>, {{{{{{ ... something not a command.
9172 "Confused by strange length of $which command($cmd)...\n";
9174 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
9176 } ## end sub cmd_prepost
9180 Contains the C<at_exit> routine that the debugger uses to issue the
9181 C<Debugged program terminated ...> message after the program completes. See
9182 the C<END> block documentation for more details.
9189 "Debugged program terminated. Use `q' to quit or `R' to restart.";
9192 package DB; # Do not trace this 1; below!