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 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
685 # modified Perl debugger, to be run from Emacs in perldb-mode
686 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
687 # Johan Vromans -- upgrade to 4.0 pl 10
688 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
690 # (We have made efforts to clarify the comments in the change log
691 # in other places; some of them may seem somewhat obscure as they
692 # were originally written, and explaining them away from the code
693 # in question seems conterproductive.. -JM)
695 ########################################################################
697 # + A lot of things changed after 0.94. First of all, core now informs
698 # debugger about entry into XSUBs, overloaded operators, tied operations,
699 # BEGIN and END. Handy with `O f=2'.
700 # + This can make debugger a little bit too verbose, please be patient
701 # and report your problems promptly.
702 # + Now the option frame has 3 values: 0,1,2. XXX Document!
703 # + Note that if DESTROY returns a reference to the object (or object),
704 # the deletion of data may be postponed until the next function call,
705 # due to the need to examine the return value.
708 # + `v' command shows versions.
711 # + `v' command shows version of readline.
712 # primitive completion works (dynamic variables, subs for `b' and `l',
713 # options). Can `p %var'
714 # + Better help (`h <' now works). New commands <<, >>, {, {{.
715 # {dump|print}_trace() coded (to be able to do it from <<cmd).
716 # + `c sub' documented.
717 # + At last enough magic combined to stop after the end of debuggee.
718 # + !! should work now (thanks to Emacs bracket matching an extra
719 # `]' in a regexp is caught).
720 # + `L', `D' and `A' span files now (as documented).
721 # + Breakpoints in `require'd code are possible (used in `R').
722 # + Some additional words on internal work of debugger.
723 # + `b load filename' implemented.
724 # + `b postpone subr' implemented.
725 # + now only `q' exits debugger (overwritable on $inhibit_exit).
726 # + When restarting debugger breakpoints/actions persist.
727 # + Buglet: When restarting debugger only one breakpoint/action per
728 # autoloaded function persists.
730 # Changes: 0.97: NonStop will not stop in at_exit().
731 # + Option AutoTrace implemented.
732 # + Trace printed differently if frames are printed too.
733 # + new `inhibitExit' option.
734 # + printing of a very long statement interruptible.
735 # Changes: 0.98: New command `m' for printing possible methods
736 # + 'l -' is a synonym for `-'.
737 # + Cosmetic bugs in printing stack trace.
738 # + `frame' & 8 to print "expanded args" in stack trace.
739 # + Can list/break in imported subs.
740 # + new `maxTraceLen' option.
741 # + frame & 4 and frame & 8 granted.
743 # + nonstoppable lines do not have `:' near the line number.
744 # + `b compile subname' implemented.
745 # + Will not use $` any more.
746 # + `-' behaves sane now.
747 # Changes: 0.99: Completion for `f', `m'.
748 # + `m' will remove duplicate names instead of duplicate functions.
749 # + `b load' strips trailing whitespace.
750 # completion ignores leading `|'; takes into account current package
751 # when completing a subroutine name (same for `l').
752 # Changes: 1.07: Many fixed by tchrist 13-March-2000
754 # + Added bare minimal security checks on perldb rc files, plus
755 # comments on what else is needed.
756 # + Fixed the ornaments that made "|h" completely unusable.
757 # They are not used in print_help if they will hurt. Strip pod
758 # if we're paging to less.
759 # + Fixed mis-formatting of help messages caused by ornaments
760 # to restore Larry's original formatting.
761 # + Fixed many other formatting errors. The code is still suboptimal,
762 # and needs a lot of work at restructuring. It's also misindented
764 # + Fixed bug where trying to look at an option like your pager
766 # + Fixed some $? processing. Note: if you use csh or tcsh, you will
767 # lose. You should consider shell escapes not using their shell,
768 # or else not caring about detailed status. This should really be
769 # unified into one place, too.
770 # + Fixed bug where invisible trailing whitespace on commands hoses you,
771 # tricking Perl into thinking you weren't calling a debugger command!
772 # + Fixed bug where leading whitespace on commands hoses you. (One
773 # suggests a leading semicolon or any other irrelevant non-whitespace
774 # to indicate literal Perl code.)
775 # + Fixed bugs that ate warnings due to wrong selected handle.
776 # + Fixed a precedence bug on signal stuff.
777 # + Fixed some unseemly wording.
778 # + Fixed bug in help command trying to call perl method code.
779 # + Fixed to call dumpvar from exception handler. SIGPIPE killed us.
781 # + Added some comments. This code is still nasty spaghetti.
782 # + Added message if you clear your pre/post command stacks which was
783 # very easy to do if you just typed a bare >, <, or {. (A command
784 # without an argument should *never* be a destructive action; this
785 # API is fundamentally screwed up; likewise option setting, which
786 # is equally buggered.)
787 # + Added command stack dump on argument of "?" for >, <, or {.
788 # + Added a semi-built-in doc viewer command that calls man with the
789 # proper %Config::Config path (and thus gets caching, man -k, etc),
790 # or else perldoc on obstreperous platforms.
791 # + Added to and rearranged the help information.
792 # + Detected apparent misuse of { ... } to declare a block; this used
793 # to work but now is a command, and mysteriously gave no complaint.
795 # Changes: 1.08: Apr 25, 2001 Jon Eveland <jweveland@yahoo.com>
797 # + This patch to perl5db.pl cleans up formatting issues on the help
798 # summary (h h) screen in the debugger. Mostly columnar alignment
799 # issues, plus converted the printed text to use all spaces, since
800 # tabs don't seem to help much here.
802 # Changes: 1.09: May 19, 2001 Ilya Zakharevich <ilya@math.ohio-state.edu>
803 # Minor bugs corrected;
804 # + Support for auto-creation of new TTY window on startup, either
805 # unconditionally, or if started as a kid of another debugger session;
806 # + New `O'ption CreateTTY
807 # I<CreateTTY> bits control attempts to create a new TTY on events:
809 # 2: debugger is started inside debugger
811 # + Code to auto-create a new TTY window on OS/2 (currently one
812 # extra window per session - need named pipes to have more...);
813 # + Simplified interface for custom createTTY functions (with a backward
814 # compatibility hack); now returns the TTY name to use; return of ''
815 # means that the function reset the I/O handles itself;
816 # + Better message on the semantic of custom createTTY function;
817 # + Convert the existing code to create a TTY into a custom createTTY
819 # + Consistent support for TTY names of the form "TTYin,TTYout";
820 # + Switch line-tracing output too to the created TTY window;
821 # + make `b fork' DWIM with CORE::GLOBAL::fork;
822 # + High-level debugger API cmd_*():
823 # cmd_b_load($filenamepart) # b load filenamepart
824 # cmd_b_line($lineno [, $cond]) # b lineno [cond]
825 # cmd_b_sub($sub [, $cond]) # b sub [cond]
826 # cmd_stop() # Control-C
827 # cmd_d($lineno) # d lineno (B)
828 # The cmd_*() API returns FALSE on failure; in this case it outputs
829 # the error message to the debugging output.
830 # + Low-level debugger API
831 # break_on_load($filename) # b load filename
832 # @files = report_break_on_load() # List files with load-breakpoints
833 # breakable_line_in_filename($name, $from [, $to])
834 # # First breakable line in the
835 # # range $from .. $to. $to defaults
836 # # to $from, and may be less than
838 # breakable_line($from [, $to]) # Same for the current file
839 # break_on_filename_line($name, $lineno [, $cond])
840 # # Set breakpoint,$cond defaults to
842 # break_on_filename_line_range($name, $from, $to [, $cond])
843 # # As above, on the first
844 # # breakable line in range
845 # break_on_line($lineno [, $cond]) # As above, in the current file
846 # break_subroutine($sub [, $cond]) # break on the first breakable line
847 # ($name, $from, $to) = subroutine_filename_lines($sub)
848 # # The range of lines of the text
849 # The low-level API returns TRUE on success, and die()s on failure.
851 # Changes: 1.10: May 23, 2001 Daniel Lewart <d-lewart@uiuc.edu>
853 # + Fixed warnings generated by "perl -dWe 42"
854 # + Corrected spelling errors
855 # + Squeezed Help (h) output into 80 columns
857 # Changes: 1.11: May 24, 2001 David Dyck <dcd@tc.fluke.com>
858 # + Made "x @INC" work like it used to
860 # Changes: 1.12: May 24, 2001 Daniel Lewart <d-lewart@uiuc.edu>
861 # + Fixed warnings generated by "O" (Show debugger options)
862 # + Fixed warnings generated by "p 42" (Print expression)
863 # Changes: 1.13: Jun 19, 2001 Scott.L.Miller@compaq.com
864 # + Added windowSize option
865 # Changes: 1.14: Oct 9, 2001 multiple
866 # + Clean up after itself on VMS (Charles Lane in 12385)
867 # + Adding "@ file" syntax (Peter Scott in 12014)
868 # + Debug reloading selfloaded stuff (Ilya Zakharevich in 11457)
869 # + $^S and other debugger fixes (Ilya Zakharevich in 11120)
870 # + Forgot a my() declaration (Ilya Zakharevich in 11085)
871 # Changes: 1.15: Nov 6, 2001 Michael G Schwern <schwern@pobox.com>
872 # + Updated 1.14 change log
873 # + Added *dbline explainatory comments
874 # + Mentioning perldebguts man page
875 # Changes: 1.16: Feb 15, 2002 Mark-Jason Dominus <mjd@plover.com>
876 # + $onetimeDump improvements
877 # Changes: 1.17: Feb 20, 2002 Richard Foley <richard.foley@rfi.net>
878 # Moved some code to cmd_[.]()'s for clarity and ease of handling,
879 # rationalised the following commands and added cmd_wrapper() to
880 # enable switching between old and frighteningly consistent new
881 # behaviours for diehards: 'o CommandSet=pre580' (sigh...)
882 # a(add), A(del) # action expr (added del by line)
883 # + b(add), B(del) # break [line] (was b,D)
884 # + w(add), W(del) # watch expr (was W,W)
885 # # added del by expr
886 # + h(summary), h h(long) # help (hh) (was h h,h)
887 # + m(methods), M(modules) # ... (was m,v)
888 # + o(option) # lc (was O)
889 # + v(view code), V(view Variables) # ... (was w,V)
890 # Changes: 1.18: Mar 17, 2002 Richard Foley <richard.foley@rfi.net>
891 # + fixed missing cmd_O bug
892 # Changes: 1.19: Mar 29, 2002 Spider Boardman
893 # + Added missing local()s -- DB::DB is called recursively.
894 # Changes: 1.20: Feb 17, 2003 Richard Foley <richard.foley@rfi.net>
895 # + pre'n'post commands no longer trashed with no args
896 # + watch val joined out of eval()
897 # Changes: 1.21: Jun 04, 2003 Joe McMahon <mcmahon@ibiblio.org>
898 # + Added comments and reformatted source. No bug fixes/enhancements.
899 # + Includes cleanup by Robin Barker and Jarkko Hietaniemi.
900 # Changes: 1.22 Jun 09, 2003 Alex Vandiver <alexmv@MIT.EDU>
901 # + Flush stdout/stderr before the debugger prompt is printed.
902 # Changes: 1.23: Dec 21, 2003 Dominique Quatravaux
903 # + Fix a side-effect of bug #24674 in the perl debugger ("odd taint bug")
904 # Changes: 1.24: Mar 03, 2004 Richard Foley <richard.foley@rfi.net>
905 # + Added command to save all debugger commands for sourcing later.
906 # + Added command to display parent inheritence tree of given class.
907 # + Fixed minor newline in history bug.
908 # Changes: 1.25: Apr 17, 2004 Richard Foley <richard.foley@rfi.net>
909 # + Fixed option bug (setting invalid options + not recognising valid short forms)
910 # Changes: 1.26: Apr 22, 2004 Richard Foley <richard.foley@rfi.net>
911 # + unfork the 5.8.x and 5.9.x debuggers.
912 # + whitespace and assertions call cleanup across versions
913 # + H * deletes (resets) history
914 # + i now handles Class + blessed objects
915 # Changes: 1.27: May 09, 2004 Richard Foley <richard.foley@rfi.net>
916 # + updated pod page references - clunky.
917 # + removed windowid restriction for forking into an xterm.
918 # + more whitespace again.
919 # + wrapped restart and enabled rerun [-n] (go back n steps) command.
920 # Changes: 1.28: Oct 12, 2004 Richard Foley <richard.foley@rfi.net>
921 # + Added threads support (inc. e and E commands)
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 =head2 THREADS SUPPORT
961 If we are running under a threaded Perl, we require threads and threads::shared
962 if the environment variable C<PERL5DB_THREADED> is set, to enable proper
963 threaded debugger control. C<-dt> can also be used to set this.
965 Each new thread will be announced and the debugger prompt will always inform
966 you of each new thread created. It will also indicate the thread id in which
967 we are currently running within the prompt like this:
971 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
972 command prompt. The prompt will show: C<[0]> when running under threads, but
973 not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
975 While running under threads, when you set or delete a breakpoint (etc.), this
976 will apply to all threads, not just the currently running one. When you are
977 in a currently executing thread, you will stay there until it completes. With
978 the current implementation it is not currently possible to hop from one thread
981 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
983 Note that threading support was built into the debugger as of Perl version
984 C<5.8.6> and debugger version C<1.2.8>.
989 # ensure we can share our non-threaded variables or no-op
990 if ($ENV{PERL5DB_THREADED}) {
992 require threads::shared;
993 import threads::shared qw(share);
997 print "Threads support enabled\n";
1004 # This would probably be better done with "use vars", but that wasn't around
1005 # when this code was originally written. (Neither was "use strict".) And on
1006 # the principle of not fiddling with something that was working, this was
1009 # These variables control the execution of 'dumpvar.pl'.
1010 $dumpvar::hashDepth,
1011 $dumpvar::arrayDepth,
1012 $dumpvar::dumpDBFiles,
1013 $dumpvar::dumpPackages,
1014 $dumpvar::quoteHighBit,
1015 $dumpvar::printUndef,
1016 $dumpvar::globPrint,
1017 $dumpvar::usageOnly,
1019 # used to save @ARGV and extract any debugger-related flags.
1022 # used to control die() reporting in diesignal()
1025 # used to prevent multiple entries to diesignal()
1026 # (if for instance diesignal() itself dies)
1029 # used to prevent the debugger from running nonstop
1035 foreach my $k (keys (%INC)) {
1036 &share(\$main::{'_<'.$filename});
1039 # Command-line + PERLLIB:
1040 # Save the contents of @INC before they are modified elsewhere.
1043 # This was an attempt to clear out the previous values of various
1044 # trapped errors. Apparently it didn't help. XXX More info needed!
1045 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
1047 # We set these variables to safe values. We don't want to blindly turn
1048 # off warnings, because other packages may still want them.
1049 $trace = $signal = $single = 0; # Uninitialized warning suppression
1050 # (local $^W cannot help - other packages!).
1052 # Default to not exiting when program finishes; print the return
1053 # value when the 'r' command is used to return from a subroutine.
1054 $inhibit_exit = $option{PrintRet} = 1;
1056 =head1 OPTION PROCESSING
1058 The debugger's options are actually spread out over the debugger itself and
1059 C<dumpvar.pl>; some of these are variables to be set, while others are
1060 subs to be called with a value. To try to make this a little easier to
1061 manage, the debugger uses a few data structures to define what options
1062 are legal and how they are to be processed.
1064 First, the C<@options> array defines the I<names> of all the options that
1071 hashDepth arrayDepth dumpDepth
1072 DumpDBFiles DumpPackages DumpReused
1073 compactDump veryCompact quote
1074 HighBit undefPrint globPrint
1075 PrintRet UsageOnly frame
1077 ReadLine NonStop LineInfo
1078 maxTraceLen recallCommand ShellBang
1079 pager tkRunning ornaments
1080 signalLevel warnLevel dieLevel
1081 inhibit_exit ImmediateStop bareStringify
1082 CreateTTY RemotePort windowSize
1083 DollarCaretP OnlyAssertions WarnAssertions
1086 @RememberOnROptions = qw(DollarCaretP OnlyAssertions);
1090 Second, C<optionVars> lists the variables that each option uses to save its
1096 hashDepth => \$dumpvar::hashDepth,
1097 arrayDepth => \$dumpvar::arrayDepth,
1098 CommandSet => \$CommandSet,
1099 DumpDBFiles => \$dumpvar::dumpDBFiles,
1100 DumpPackages => \$dumpvar::dumpPackages,
1101 DumpReused => \$dumpvar::dumpReused,
1102 HighBit => \$dumpvar::quoteHighBit,
1103 undefPrint => \$dumpvar::printUndef,
1104 globPrint => \$dumpvar::globPrint,
1105 UsageOnly => \$dumpvar::usageOnly,
1106 CreateTTY => \$CreateTTY,
1107 bareStringify => \$dumpvar::bareStringify,
1109 AutoTrace => \$trace,
1110 inhibit_exit => \$inhibit_exit,
1111 maxTraceLen => \$maxtrace,
1112 ImmediateStop => \$ImmediateStop,
1113 RemotePort => \$remoteport,
1114 windowSize => \$window,
1115 WarnAssertions => \$warnassertions,
1120 Third, C<%optionAction> defines the subroutine to be called to process each
1126 compactDump => \&dumpvar::compactDump,
1127 veryCompact => \&dumpvar::veryCompact,
1128 quote => \&dumpvar::quote,
1131 ReadLine => \&ReadLine,
1132 NonStop => \&NonStop,
1133 LineInfo => \&LineInfo,
1134 recallCommand => \&recallCommand,
1135 ShellBang => \&shellBang,
1137 signalLevel => \&signalLevel,
1138 warnLevel => \&warnLevel,
1139 dieLevel => \&dieLevel,
1140 tkRunning => \&tkRunning,
1141 ornaments => \&ornaments,
1142 RemotePort => \&RemotePort,
1143 DollarCaretP => \&DollarCaretP,
1144 OnlyAssertions=> \&OnlyAssertions,
1149 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1154 # Note that this list is not complete: several options not listed here
1155 # actually require that dumpvar.pl be loaded for them to work, but are
1156 # not in the table. A subsequent patch will correct this problem; for
1157 # the moment, we're just recommenting, and we are NOT going to change
1160 compactDump => 'dumpvar.pl',
1161 veryCompact => 'dumpvar.pl',
1162 quote => 'dumpvar.pl',
1167 There are a number of initialization-related variables which can be set
1168 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1169 variable. These are:
1173 =item C<$rl> - readline control XXX needs more explanation
1175 =item C<$warnLevel> - whether or not debugger takes over warning handling
1177 =item C<$dieLevel> - whether or not debugger takes over die handling
1179 =item C<$signalLevel> - whether or not debugger takes over signal handling
1181 =item C<$pre> - preprompt actions (array reference)
1183 =item C<$post> - postprompt actions (array reference)
1187 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1189 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1195 # These guys may be defined in $ENV{PERL5DB} :
1196 $rl = 1 unless defined $rl;
1197 $warnLevel = 1 unless defined $warnLevel;
1198 $dieLevel = 1 unless defined $dieLevel;
1199 $signalLevel = 1 unless defined $signalLevel;
1200 $pre = [] unless defined $pre;
1201 $post = [] unless defined $post;
1202 $pretype = [] unless defined $pretype;
1203 $CreateTTY = 3 unless defined $CreateTTY;
1204 $CommandSet = '580' unless defined $CommandSet;
1209 share($signalLevel);
1219 The default C<die>, C<warn>, and C<signal> handlers are set up.
1223 warnLevel($warnLevel);
1224 dieLevel($dieLevel);
1225 signalLevel($signalLevel);
1229 The pager to be used is needed next. We try to get it from the
1230 environment first. if it's not defined there, we try to find it in
1231 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1232 then call the C<pager()> function to save the pager name.
1236 # This routine makes sure $pager is set up so that '|' can use it.
1239 # If PAGER is defined in the environment, use it.
1243 # If not, see if Config.pm defines it.
1244 : eval { require Config }
1245 && defined $Config::Config{pager}
1246 ? $Config::Config{pager}
1248 # If not, fall back to 'more'.
1251 unless defined $pager;
1255 We set up the command to be used to access the man pages, the command
1256 recall character ("!" unless otherwise defined) and the shell escape
1257 character ("!" unless otherwise defined). Yes, these do conflict, and
1258 neither works in the debugger at the moment.
1264 # Set up defaults for command recall and shell escape (note:
1265 # these currently don't work in linemode debugging).
1266 &recallCommand("!") unless defined $prc;
1267 &shellBang("!") unless defined $psh;
1271 We then set up the gigantic string containing the debugger help.
1272 We also set the limit on the number of arguments we'll display during a
1279 # If we didn't get a default for the length of eval/stack trace args,
1281 $maxtrace = 400 unless defined $maxtrace;
1283 =head2 SETTING UP THE DEBUGGER GREETING
1285 The debugger 'greeting' helps to inform the user how many debuggers are
1286 running, and whether the current debugger is the primary or a child.
1288 If we are the primary, we just hang onto our pid so we'll have it when
1289 or if we start a child debugger. If we are a child, we'll set things up
1290 so we'll have a unique greeting and so the parent will give us our own
1293 We save the current contents of the C<PERLDB_PIDS> environment variable
1294 because we mess around with it. We'll also need to hang onto it because
1295 we'll need it if we restart.
1297 Child debuggers make a label out of the current PID structure recorded in
1298 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1299 yet so the parent will give them one later via C<resetterm()>.
1303 # Save the current contents of the environment; we're about to
1304 # much with it. We'll need this if we have to restart.
1305 $ini_pids = $ENV{PERLDB_PIDS};
1307 if ( defined $ENV{PERLDB_PIDS} ) {
1309 # We're a child. Make us a label out of the current PID structure
1310 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1311 # a term yet so the parent will give us one later via resetterm().
1312 $pids = "[$ENV{PERLDB_PIDS}]";
1313 $ENV{PERLDB_PIDS} .= "->$$";
1315 } ## end if (defined $ENV{PERLDB_PIDS...
1318 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1319 # child debugger, and mark us as the parent, so we'll know to set up
1320 # more TTY's is we have to.
1321 $ENV{PERLDB_PIDS} = "$$";
1328 # Sets up $emacs as a synonym for $slave_editor.
1329 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1331 =head2 READING THE RC FILE
1333 The debugger will read a file of initialization options if supplied. If
1334 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1338 # As noted, this test really doesn't check accurately that the debugger
1339 # is running at a terminal or not.
1341 if ( -e "/dev/tty" ) { # this is the wrong metric!
1342 $rcfile = ".perldb";
1345 $rcfile = "perldb.ini";
1350 The debugger does a safety test of the file to be read. It must be owned
1351 either by the current user or root, and must only be writable by the owner.
1355 # This wraps a safety test around "do" to read and evaluate the init file.
1357 # This isn't really safe, because there's a race
1358 # between checking and opening. The solution is to
1359 # open and fstat the handle, but then you have to read and
1360 # eval the contents. But then the silly thing gets
1361 # your lexical scope, which is unfortunate at best.
1365 # Just exactly what part of the word "CORE::" don't you understand?
1366 local $SIG{__WARN__};
1367 local $SIG{__DIE__};
1369 unless ( is_safe_file($file) ) {
1370 CORE::warn <<EO_GRIPE;
1371 perldb: Must not source insecure rcfile $file.
1372 You or the superuser must be the owner, and it must not
1373 be writable by anyone but its owner.
1376 } ## end unless (is_safe_file($file...
1379 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1380 } ## end sub safe_do
1382 # This is the safety test itself.
1384 # Verifies that owner is either real user or superuser and that no
1385 # one but owner may write to it. This function is of limited use
1386 # when called on a path instead of upon a handle, because there are
1387 # no guarantees that filename (by dirent) whose file (by ino) is
1388 # eventually accessed is the same as the one tested.
1389 # Assumes that the file's existence is not in doubt.
1392 stat($path) || return; # mysteriously vaporized
1393 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1395 return 0 if $uid != 0 && $uid != $<;
1396 return 0 if $mode & 022;
1398 } ## end sub is_safe_file
1400 # If the rcfile (whichever one we decided was the right one to read)
1401 # exists, we safely do it.
1403 safe_do("./$rcfile");
1406 # If there isn't one here, try the user's home directory.
1407 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1408 safe_do("$ENV{HOME}/$rcfile");
1411 # Else try the login directory.
1412 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1413 safe_do("$ENV{LOGDIR}/$rcfile");
1416 # If the PERLDB_OPTS variable has options in it, parse those out next.
1417 if ( defined $ENV{PERLDB_OPTS} ) {
1418 parse_options( $ENV{PERLDB_OPTS} );
1423 The last thing we do during initialization is determine which subroutine is
1424 to be used to obtain a new terminal when a new debugger is started. Right now,
1425 the debugger only handles X Windows and OS/2.
1429 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1430 # Works if you're running an xterm or xterm-like window, or you're on
1431 # OS/2. This may need some expansion: for instance, this doesn't handle
1432 # OS X Terminal windows.
1435 not defined &get_fork_TTY # no routine exists,
1436 and defined $ENV{TERM} # and we know what kind
1437 # of terminal this is,
1438 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1439 # and defined $ENV{WINDOWID} # and we know what window this is, <- wrong metric
1440 and defined $ENV{DISPLAY} # and what display it's on,
1443 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1444 } ## end if (not defined &get_fork_TTY...
1445 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1446 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1449 # untaint $^O, which may have been tainted by the last statement.
1450 # see bug [perl #24674]
1454 # Here begin the unreadable code. It needs fixing.
1456 =head2 RESTART PROCESSING
1458 This section handles the restart command. When the C<R> command is invoked, it
1459 tries to capture all of the state it can into environment variables, and
1460 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1461 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1462 the R command stuffed into the environment variables.
1464 PERLDB_RESTART - flag only, contains no restart data itself.
1465 PERLDB_HIST - command history, if it's available
1466 PERLDB_ON_LOAD - breakpoints set by the rc file
1467 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1468 PERLDB_VISITED - files that had breakpoints
1469 PERLDB_FILE_... - breakpoints for a file
1470 PERLDB_OPT - active options
1471 PERLDB_INC - the original @INC
1472 PERLDB_PRETYPE - preprompt debugger actions
1473 PERLDB_PRE - preprompt Perl code
1474 PERLDB_POST - post-prompt Perl code
1475 PERLDB_TYPEAHEAD - typeahead captured by readline()
1477 We chug through all these variables and plug the values saved in them
1478 back into the appropriate spots in the debugger.
1482 if ( exists $ENV{PERLDB_RESTART} ) {
1484 # We're restarting, so we don't need the flag that says to restart anymore.
1485 delete $ENV{PERLDB_RESTART};
1488 @hist = get_list('PERLDB_HIST');
1489 %break_on_load = get_list("PERLDB_ON_LOAD");
1490 %postponed = get_list("PERLDB_POSTPONE");
1494 share(%break_on_load);
1497 # restore breakpoints/actions
1498 my @had_breakpoints = get_list("PERLDB_VISITED");
1499 for ( 0 .. $#had_breakpoints ) {
1500 my %pf = get_list("PERLDB_FILE_$_");
1501 $postponed_file{ $had_breakpoints[$_] } = \%pf if %pf;
1505 my %opt = get_list("PERLDB_OPT");
1507 while ( ( $opt, $val ) = each %opt ) {
1508 $val =~ s/[\\\']/\\$1/g;
1509 parse_options("$opt'$val'");
1512 # restore original @INC
1513 @INC = get_list("PERLDB_INC");
1516 # return pre/postprompt actions and typeahead buffer
1517 $pretype = [ get_list("PERLDB_PRETYPE") ];
1518 $pre = [ get_list("PERLDB_PRE") ];
1519 $post = [ get_list("PERLDB_POST") ];
1520 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1521 } ## end if (exists $ENV{PERLDB_RESTART...
1523 =head2 SETTING UP THE TERMINAL
1525 Now, we'll decide how the debugger is going to interact with the user.
1526 If there's no TTY, we set the debugger to run non-stop; there's not going
1527 to be anyone there to enter commands.
1538 If there is a TTY, we have to determine who it belongs to before we can
1539 proceed. If this is a slave editor or graphical debugger (denoted by
1540 the first command-line switch being '-emacs'), we shift this off and
1541 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1547 # Is Perl being run from a slave editor or graphical debugger?
1548 # If so, don't use readline, and set $slave_editor = 1.
1550 ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) );
1551 $rl = 0, shift(@main::ARGV) if $slave_editor;
1553 #require Term::ReadLine;
1557 We then determine what the console should be on various systems:
1561 =item * Cygwin - We use C<stdin> instead of a separate device.
1565 if ( $^O eq 'cygwin' ) {
1567 # /dev/tty is binary. use stdin for textmode
1571 =item * Unix - use C</dev/tty>.
1575 elsif ( -e "/dev/tty" ) {
1576 $console = "/dev/tty";
1579 =item * Windows or MSDOS - use C<con>.
1583 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1587 =item * MacOS - use C<Dev:Console:Perl Debug> if this is the MPW version; C<Dev:
1588 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.)
1592 elsif ( $^O eq 'MacOS' ) {
1593 if ( $MacPerl::Version !~ /MPW/ ) {
1595 "Dev:Console:Perl Debug"; # Separate window for application
1598 $console = "Dev:Console";
1600 } ## end elsif ($^O eq 'MacOS')
1602 =item * VMS - use C<sys$command>.
1608 # everything else is ...
1609 $console = "sys\$command";
1616 Several other systems don't use a specific console. We C<undef $console>
1617 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1618 with a slave editor, Epoc).
1622 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1624 # /dev/tty is binary. use stdin for textmode
1628 if ( $^O eq 'NetWare' ) {
1630 # /dev/tty is binary. use stdin for textmode
1634 # In OS/2, we need to use STDIN to get textmode too, even though
1635 # it pretty much looks like Unix otherwise.
1636 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1641 # EPOC also falls into the 'got to use STDIN' camp.
1642 if ( $^O eq 'epoc' ) {
1648 If there is a TTY hanging around from a parent, we use that as the console.
1652 $console = $tty if defined $tty;
1654 =head2 SOCKET HANDLING
1656 The debugger is capable of opening a socket and carrying out a debugging
1657 session over the socket.
1659 If C<RemotePort> was defined in the options, the debugger assumes that it
1660 should try to start a debugging session on that port. It builds the socket
1661 and then tries to connect the input and output filehandles to it.
1665 # Handle socket stuff.
1667 if ( defined $remoteport ) {
1669 # If RemotePort was defined in the options, connect input and output
1672 $OUT = new IO::Socket::INET(
1674 PeerAddr => $remoteport,
1677 if ( !$OUT ) { die "Unable to connect to remote host: $remoteport\n"; }
1679 } ## end if (defined $remoteport)
1683 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1684 this is probably a situation where multiple debuggers are running (for example,
1685 a backticked command that starts up another debugger). We create a new IN and
1686 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1694 # Two debuggers running (probably a system or a backtick that invokes
1695 # the debugger itself under the running one). create a new IN and OUT
1696 # filehandle, and do the necessary mojo to create a new tty if we
1697 # know how, and we can.
1698 create_IN_OUT(4) if $CreateTTY & 4;
1701 # If we have a console, check to see if there are separate ins and
1702 # outs to open. (They are assumed identiical if not.)
1704 my ( $i, $o ) = split /,/, $console;
1705 $o = $i unless defined $o;
1707 # read/write on in, or just read, or read on STDIN.
1709 || open( IN, "<$i" )
1710 || open( IN, "<&STDIN" );
1712 # read/write/create/clobber out, or write/create/clobber out,
1713 # or merge with STDERR, or merge with STDOUT.
1715 || open( OUT, ">$o" )
1716 || open( OUT, ">&STDERR" )
1717 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1719 } ## end if ($console)
1720 elsif ( not defined $console ) {
1722 # No console. Open STDIN.
1723 open( IN, "<&STDIN" );
1725 # merge with STDERR, or with STDOUT.
1726 open( OUT, ">&STDERR" )
1727 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1728 $console = 'STDIN/OUT';
1729 } ## end elsif (not defined $console)
1731 # Keep copies of the filehandles so that when the pager runs, it
1732 # can close standard input without clobbering ours.
1733 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1734 } ## end elsif (from if(defined $remoteport))
1736 # Unbuffer DB::OUT. We need to see responses right away.
1737 my $previous = select($OUT);
1738 $| = 1; # for DB::OUT
1741 # Line info goes to debugger output unless pointed elsewhere.
1742 # Pointing elsewhere makes it possible for slave editors to
1743 # keep track of file and position. We have both a filehandle
1744 # and a I/O description to keep track of.
1745 $LINEINFO = $OUT unless defined $LINEINFO;
1746 $lineinfo = $console unless defined $lineinfo;
1747 # share($LINEINFO); # <- unable to share globs
1752 To finish initialization, we show the debugger greeting,
1753 and then call the C<afterinit()> subroutine if there is one.
1757 # Show the debugger greeting.
1758 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1759 unless ($runnonstop) {
1762 if ( $term_pid eq '-1' ) {
1763 print $OUT "\nDaughter DB session started...\n";
1766 print $OUT "\nLoading DB routines from $header\n";
1769 $slave_editor ? "enabled" : "available", ".\n"
1772 "\nEnter h or `h h' for help, or `$doccmd perldebug' for more help.\n\n";
1773 } ## end else [ if ($term_pid eq '-1')
1774 } ## end unless ($runnonstop)
1775 } ## end else [ if ($notty)
1777 # XXX This looks like a bug to me.
1778 # Why copy to @ARGS and then futz with @args?
1781 # Make sure backslashes before single quotes are stripped out, and
1782 # keep args unless they are numeric (XXX why?)
1783 # s/\'/\\\'/g; # removed while not justified understandably
1784 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1787 # If there was an afterinit() sub defined, call it. It will get
1788 # executed in our scope, so it can fiddle with debugger globals.
1789 if ( defined &afterinit ) { # May be defined in $rcfile
1793 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1796 ############################################################ Subroutines
1802 This gigantic subroutine is the heart of the debugger. Called before every
1803 statement, its job is to determine if a breakpoint has been reached, and
1804 stop if so; read commands from the user, parse them, and execute
1805 them, and hen send execution off to the next statement.
1807 Note that the order in which the commands are processed is very important;
1808 some commands earlier in the loop will actually alter the C<$cmd> variable
1809 to create other commands to be executed later. This is all highly "optimized"
1810 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1811 see what's happening in any given command.
1817 # lock the debugger and get the thread id for the prompt
1820 if ($ENV{PERL5DB_THREADED}) {
1821 $tid = eval { "[".threads->self->tid."]" };
1824 # Check for whether we should be running continuously or not.
1825 # _After_ the perl program is compiled, $single is set to 1:
1826 if ( $single and not $second_time++ ) {
1828 # Options say run non-stop. Run until we get an interrupt.
1829 if ($runnonstop) { # Disable until signal
1830 # If there's any call stack in place, turn off single
1831 # stepping into subs throughout the stack.
1832 for ( $i = 0 ; $i <= $stack_depth ; ) {
1833 $stack[ $i++ ] &= ~1;
1836 # And we are now no longer in single-step mode.
1839 # If we simply returned at this point, we wouldn't get
1840 # the trace info. Fall on through.
1842 } ## end if ($runnonstop)
1844 elsif ($ImmediateStop) {
1846 # We are supposed to stop here; XXX probably a break.
1847 $ImmediateStop = 0; # We've processed it; turn it off
1848 $signal = 1; # Simulate an interrupt to force
1849 # us into the command loop
1851 } ## end if ($single and not $second_time...
1853 # If we're in single-step mode, or an interrupt (real or fake)
1854 # has occurred, turn off non-stop mode.
1855 $runnonstop = 0 if $single or $signal;
1857 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1858 # The code being debugged may have altered them.
1861 # Since DB::DB gets called after every line, we can use caller() to
1862 # figure out where we last were executing. Sneaky, eh? This works because
1863 # caller is returning all the extra information when called from the
1865 local ( $package, $filename, $line ) = caller;
1866 local $filename_ini = $filename;
1868 # set up the context for DB::eval, so it can properly execute
1869 # code on behalf of the user. We add the package in so that the
1870 # code is eval'ed in the proper package (not in the debugger!).
1871 local $usercontext =
1872 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' . "package $package;";
1874 # Create an alias to the active file magical array to simplify
1876 local (*dbline) = $main::{ '_<' . $filename };
1878 # we need to check for pseudofiles on Mac OS (these are files
1879 # not attached to a filename, but instead stored in Dev:Pseudo)
1880 if ( $^O eq 'MacOS' && $#dbline < 0 ) {
1881 $filename_ini = $filename = 'Dev:Pseudo';
1882 *dbline = $main::{ '_<' . $filename };
1885 # Last line in the program.
1886 local $max = $#dbline;
1888 # if we have something here, see if we should break.
1890 && ( ( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1893 # Stop if the stop criterion says to just stop.
1894 if ( $stop eq '1' ) {
1898 # It's a conditional stop; eval it in the user's context and
1899 # see if we should stop. If so, remove the one-time sigil.
1901 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1903 $dbline{$line} =~ s/;9($|\0)/$1/;
1905 } ## end if ($dbline{$line} && ...
1907 # Preserve the current stop-or-not, and see if any of the W
1908 # (watch expressions) has changed.
1909 my $was_signal = $signal;
1911 # If we have any watch expressions ...
1913 for ( my $n = 0 ; $n <= $#to_watch ; $n++ ) {
1914 $evalarg = $to_watch[$n];
1915 local $onetimeDump; # Tell DB::eval() to not output results
1917 # Fix context DB::eval() wants to return an array, but
1918 # we need a scalar here.
1919 my ($val) = join( "', '", &eval );
1920 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
1923 if ( $val ne $old_watch[$n] ) {
1925 # Yep! Show the difference, and fake an interrupt.
1928 Watchpoint $n:\t$to_watch[$n] changed:
1929 old value:\t$old_watch[$n]
1932 $old_watch[$n] = $val;
1933 } ## end if ($val ne $old_watch...
1934 } ## end for (my $n = 0 ; $n <= ...
1935 } ## end if ($trace & 2)
1937 =head2 C<watchfunction()>
1939 C<watchfunction()> is a function that can be defined by the user; it is a
1940 function which will be run on each entry to C<DB::DB>; it gets the
1941 current package, filename, and line as its parameters.
1943 The watchfunction can do anything it likes; it is executing in the
1944 debugger's context, so it has access to all of the debugger's internal
1945 data structures and functions.
1947 C<watchfunction()> can control the debugger's actions. Any of the following
1948 will cause the debugger to return control to the user's program after
1949 C<watchfunction()> executes:
1953 =item * Returning a false value from the C<watchfunction()> itself.
1955 =item * Altering C<$single> to a false value.
1957 =item * Altering C<$signal> to a false value.
1959 =item * Turning off the '4' bit in C<$trace> (this also disables the
1960 check for C<watchfunction()>. This can be done with
1968 # If there's a user-defined DB::watchfunction, call it with the
1969 # current package, filename, and line. The function executes in
1971 if ( $trace & 4 ) { # User-installed watch
1973 if watchfunction( $package, $filename, $line )
1976 and not( $trace & ~4 );
1977 } ## end if ($trace & 4)
1979 # Pick up any alteration to $signal in the watchfunction, and
1980 # turn off the signal now.
1981 $was_signal = $signal;
1984 =head2 GETTING READY TO EXECUTE COMMANDS
1986 The debugger decides to take control if single-step mode is on, the
1987 C<t> command was entered, or the user generated a signal. If the program
1988 has fallen off the end, we set things up so that entering further commands
1989 won't cause trouble, and we say that the program is over.
1993 # Check to see if we should grab control ($single true,
1994 # trace set appropriately, or we got a signal).
1995 if ( $single || ( $trace & 1 ) || $was_signal ) {
1997 # Yes, grab control.
1998 if ($slave_editor) {
2000 # Tell the editor to update its position.
2001 $position = "\032\032$filename:$line:0\n";
2002 print_lineinfo($position);
2007 Special check: if we're in package C<DB::fake>, we've gone through the
2008 C<END> block at least once. We set up everything so that we can continue
2009 to enter commands and have a valid context to be in.
2013 elsif ( $package eq 'DB::fake' ) {
2015 # Fallen off the end already.
2018 Debugged program terminated. Use B<q> to quit or B<R> to restart,
2019 use B<O> I<inhibit_exit> to avoid stopping after program termination,
2020 B<h q>, B<h R> or B<h O> to get additional info.
2023 # Set the DB::eval context appropriately.
2026 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;'
2027 . "package $package;"; # this won't let them modify, alas
2028 } ## end elsif ($package eq 'DB::fake')
2032 If the program hasn't finished executing, we scan forward to the
2033 next executable line, print that out, build the prompt from the file and line
2034 number information, and print that.
2040 # Still somewhere in the midst of execution. Set up the
2042 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
2043 # Perl 5 ones (sorry, we don't print Klingon
2046 $prefix = $sub =~ /::/ ? "" : "${'package'}::";
2047 $prefix .= "$sub($filename:";
2048 $after = ( $dbline[$line] =~ /\n$/ ? '' : "\n" );
2050 # Break up the prompt if it's really long.
2051 if ( length($prefix) > 30 ) {
2052 $position = "$prefix$line):\n$line:\t$dbline[$line]$after";
2058 $position = "$prefix$line$infix$dbline[$line]$after";
2061 # Print current line info, indenting if necessary.
2063 print_lineinfo( ' ' x $stack_depth,
2064 "$line:\t$dbline[$line]$after" );
2067 print_lineinfo($position);
2070 # Scan forward, stopping at either the end or the next
2072 for ( $i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i )
2075 # Drop out on null statements, block closers, and comments.
2076 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/;
2078 # Drop out if the user interrupted us.
2081 # Append a newline if the line doesn't have one. Can happen
2082 # in eval'ed text, for instance.
2083 $after = ( $dbline[$i] =~ /\n$/ ? '' : "\n" );
2085 # Next executable line.
2086 $incr_pos = "$prefix$i$infix$dbline[$i]$after";
2087 $position .= $incr_pos;
2090 # Print it indented if tracing is on.
2091 print_lineinfo( ' ' x $stack_depth,
2092 "$i:\t$dbline[$i]$after" );
2095 print_lineinfo($incr_pos);
2097 } ## end for ($i = $line + 1 ; $i...
2098 } ## end else [ if ($slave_editor)
2099 } ## end if ($single || ($trace...
2103 If there's an action to be executed for the line we stopped at, execute it.
2104 If there are any preprompt actions, execute those as well.
2108 # If there's an action, do it now.
2109 $evalarg = $action, &eval if $action;
2111 # Are we nested another level (e.g., did we evaluate a function
2112 # that had a breakpoint in it at the debugger prompt)?
2113 if ( $single || $was_signal ) {
2115 # Yes, go down a level.
2116 local $level = $level + 1;
2118 # Do any pre-prompt actions.
2119 foreach $evalarg (@$pre) {
2123 # Complain about too much recursion if we passed the limit.
2124 print $OUT $stack_depth . " levels deep in subroutine calls!\n"
2127 # The line we're currently on. Set $incr to -1 to stay here
2128 # until we get a command that tells us to advance.
2130 $incr = -1; # for backward motion.
2132 # Tack preprompt debugger actions ahead of any actual input.
2133 @typeahead = ( @$pretype, @typeahead );
2135 =head2 WHERE ARE WE?
2137 XXX Relocate this section?
2139 The debugger normally shows the line corresponding to the current line of
2140 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2141 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2143 C<$incr> controls by how many lines the "current" line should move forward
2144 after a command is executed. If set to -1, this indicates that the "current"
2145 line shouldn't change.
2147 C<$start> is the "current" line. It is used for things like knowing where to
2148 move forwards or backwards from when doing an C<L> or C<-> command.
2150 C<$max> tells the debugger where the last line of the current file is. It's
2151 used to terminate loops most often.
2153 =head2 THE COMMAND LOOP
2155 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2160 =item * The outer part of the loop, starting at the C<CMD> label. This loop
2161 reads a command and then executes it.
2163 =item * The inner part of the loop, starting at the C<PIPE> label. This part
2164 is wholly contained inside the C<CMD> block and only executes a command.
2165 Used to handle commands running inside a pager.
2169 So why have two labels to restart the loop? Because sometimes, it's easier to
2170 have a command I<generate> another command and then re-execute the loop to do
2171 the new command. This is faster, but perhaps a bit more convoluted.
2175 # The big command dispatch loop. It keeps running until the
2176 # user yields up control again.
2178 # If we have a terminal for input, and we get something back
2179 # from readline(), keep on processing.
2183 # We have a terminal, or can get one ...
2184 ( $term || &setterm ),
2186 # ... and it belogs to this PID or we get one for this PID ...
2187 ( $term_pid == $$ or resetterm(1) ),
2189 # ... and we got a line of command input ...
2192 "$pidprompt $tid DB"
2195 . ( '>' x $level ) . " "
2202 # ... try to execute the input as debugger commands.
2204 # Don't stop running.
2207 # No signal is active.
2210 # Handle continued commands (ending with \):
2211 $cmd =~ s/\\$/\n/ && do {
2212 $cmd .= &readline(" cont: ");
2216 =head4 The null command
2218 A newline entered by itself means "re-execute the last command". We grab the
2219 command out of C<$laststep> (where it was recorded previously), and copy it
2220 back into C<$cmd> to be executed below. If there wasn't any previous command,
2221 we'll do nothing below (no command will match). If there was, we also save it
2222 in the command history and fall through to allow the command parsing to pick
2227 # Empty input means repeat the last command.
2228 $cmd =~ /^$/ && ( $cmd = $laststep );
2229 chomp($cmd); # get rid of the annoying extra newline
2230 push( @hist, $cmd ) if length($cmd) > 1;
2231 push( @truehist, $cmd );
2235 # This is a restart point for commands that didn't arrive
2236 # via direct user input. It allows us to 'redo PIPE' to
2237 # re-execute command processing without reading a new command.
2239 $cmd =~ s/^\s+//s; # trim annoying leading whitespace
2240 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace
2241 ($i) = split( /\s+/, $cmd );
2243 =head3 COMMAND ALIASES
2245 The debugger can create aliases for commands (these are stored in the
2246 C<%alias> hash). Before a command is executed, the command loop looks it up
2247 in the alias hash and substitutes the contents of the alias for the command,
2248 completely replacing it.
2252 # See if there's an alias for the command, and set it up if so.
2255 # Squelch signal handling; we want to keep control here
2256 # if something goes loco during the alias eval.
2257 local $SIG{__DIE__};
2258 local $SIG{__WARN__};
2260 # This is a command, so we eval it in the DEBUGGER's
2261 # scope! Otherwise, we can't see the special debugger
2262 # variables, or get to the debugger's subs. (Well, we
2263 # _could_, but why make it even more complicated?)
2264 eval "\$cmd =~ $alias{$i}";
2267 print $OUT "Couldn't evaluate `$i' alias: $@";
2270 } ## end if ($alias{$i})
2272 =head3 MAIN-LINE COMMANDS
2274 All of these commands work up to and after the program being debugged has
2279 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2280 try to execute further, cleaning any restart-related stuff out of the
2281 environment, and executing with the last value of C<$?>.
2285 $cmd =~ /^q$/ && do {
2293 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2297 $cmd =~ /^t$/ && do {
2300 print $OUT "Trace = "
2301 . ( ( $trace & 1 ) ? "on" : "off" ) . "\n";
2305 =head4 C<S> - list subroutines matching/not matching a pattern
2307 Walks through C<%sub>, checking to see whether or not to print the name.
2311 $cmd =~ /^S(\s+(!)?(.+))?$/ && do {
2313 $Srev = defined $2; # Reverse scan?
2314 $Spatt = $3; # The pattern (if any) to use.
2315 $Snocheck = !defined $1; # No args - print all subs.
2317 # Need to make these sane here.
2321 # Search through the debugger's magical hash of subs.
2322 # If $nocheck is true, just print the sub name.
2323 # Otherwise, check it against the pattern. We then use
2324 # the XOR trick to reverse the condition as required.
2325 foreach $subname ( sort( keys %sub ) ) {
2326 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2327 print $OUT $subname, "\n";
2333 =head4 C<X> - list variables in current package
2335 Since the C<V> command actually processes this, just change this to the
2336 appropriate C<V> command and fall through.
2340 $cmd =~ s/^X\b/V $package/;
2342 =head4 C<V> - list variables
2344 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2348 # Bare V commands get the currently-being-debugged package
2350 $cmd =~ /^V$/ && do {
2351 $cmd = "V $package";
2354 # V - show variables in package.
2355 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
2357 # Save the currently selected filehandle and
2358 # force output to debugger's filehandle (dumpvar
2359 # just does "print" for output).
2360 local ($savout) = select($OUT);
2362 # Grab package name and variables to dump.
2364 @vars = split( ' ', $2 );
2366 # If main::dumpvar isn't here, get it.
2367 do 'dumpvar.pl' unless defined &main::dumpvar;
2368 if ( defined &main::dumpvar ) {
2370 # We got it. Turn off subroutine entry/exit messages
2371 # for the moment, along with return values.
2375 # must detect sigpipe failures - not catching
2376 # then will cause the debugger to die.
2380 defined $option{dumpDepth}
2381 ? $option{dumpDepth}
2382 : -1, # assume -1 unless specified
2387 # The die doesn't need to include the $@, because
2388 # it will automatically get propagated for us.
2390 die unless $@ =~ /dumpvar print failed/;
2392 } ## end if (defined &main::dumpvar)
2395 # Couldn't load dumpvar.
2396 print $OUT "dumpvar.pl not available.\n";
2399 # Restore the output filehandle, and go round again.
2404 =head4 C<x> - evaluate and print an expression
2406 Hands the expression off to C<DB::eval>, setting it up to print the value
2407 via C<dumpvar.pl> instead of just printing it directly.
2411 $cmd =~ s/^x\b/ / && do { # Remainder gets done by DB::eval()
2412 $onetimeDump = 'dump'; # main::dumpvar shows the output
2414 # handle special "x 3 blah" syntax XXX propagate
2415 # doc back to special variables.
2416 if ( $cmd =~ s/^\s*(\d+)(?=\s)/ / ) {
2417 $onetimedumpDepth = $1;
2421 =head4 C<m> - print methods
2423 Just uses C<DB::methods> to determine what methods are available.
2427 $cmd =~ s/^m\s+([\w:]+)\s*$/ / && do {
2432 # m expr - set up DB::eval to do the work
2433 $cmd =~ s/^m\b/ / && do { # Rest gets done by DB::eval()
2434 $onetimeDump = 'methods'; # method output gets used there
2437 =head4 C<f> - switch files
2441 $cmd =~ /^f\b\s*(.*)/ && do {
2445 # help for no arguments (old-style was return from sub).
2448 "The old f command is now the r command.\n"; # hint
2449 print $OUT "The new f command switches filenames.\n";
2451 } ## end if (!$file)
2453 # if not in magic file list, try a close match.
2454 if ( !defined $main::{ '_<' . $file } ) {
2455 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2457 $try = substr( $try, 2 );
2458 print $OUT "Choosing $try matching `$file':\n";
2461 } ## end if (($try) = grep(m#^_<.*$file#...
2462 } ## end if (!defined $main::{ ...
2464 # If not successfully switched now, we failed.
2465 if ( !defined $main::{ '_<' . $file } ) {
2466 print $OUT "No file matching `$file' is loaded.\n";
2470 # We switched, so switch the debugger internals around.
2471 elsif ( $file ne $filename ) {
2472 *dbline = $main::{ '_<' . $file };
2477 } ## end elsif ($file ne $filename)
2479 # We didn't switch; say we didn't.
2481 print $OUT "Already in $file.\n";
2486 =head4 C<.> - return to last-executed line.
2488 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2489 and then we look up the line in the magical C<%dbline> hash.
2494 $cmd =~ /^\.$/ && do {
2495 $incr = -1; # stay at current line
2497 # Reset everything to the old location.
2499 $filename = $filename_ini;
2500 *dbline = $main::{ '_<' . $filename };
2504 print_lineinfo($position);
2508 =head4 C<-> - back one window
2510 We change C<$start> to be one window back; if we go back past the first line,
2511 we set it to be the first line. We ser C<$incr> to put us back at the
2512 currently-executing line, and then put a C<l $start +> (list one window from
2513 C<$start>) in C<$cmd> to be executed later.
2517 # - - back a window.
2518 $cmd =~ /^-$/ && do {
2520 # back up by a window; go to 1 if back too far.
2521 $start -= $incr + $window + 1;
2522 $start = 1 if $start <= 0;
2523 $incr = $window - 1;
2525 # Generate and execute a "l +" command (handled below).
2526 $cmd = 'l ' . ($start) . '+';
2529 =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>, {, {{>
2531 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2532 problems, most notably that the default case of several commands destroying
2533 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2534 retain the old commands for those who were used to using them or who preferred
2535 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2536 deal with them instead of processing them in-line.
2540 # All of these commands were remapped in perl 5.8.0;
2541 # we send them off to the secondary dispatcher (see below).
2542 $cmd =~ /^([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so && do {
2543 &cmd_wrapper( $1, $2, $line );
2547 =head4 C<y> - List lexicals in higher scope
2549 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2550 above the current one and then displays then using C<dumpvar.pl>.
2554 $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/ && do {
2556 # See if we've got the necessary support.
2557 eval { require PadWalker; PadWalker->VERSION(0.08) }
2560 ? "PadWalker module not found - please install\n"
2565 # Load up dumpvar if we don't have it. If we can, that is.
2566 do 'dumpvar.pl' unless defined &main::dumpvar;
2567 defined &main::dumpvar
2568 or print $OUT "dumpvar.pl not available.\n"
2571 # Got all the modules we need. Find them and print them.
2572 my @vars = split( ' ', $2 || '' );
2575 my $h = eval { PadWalker::peek_my( ( $1 || 0 ) + 1 ) };
2577 # Oops. Can't find it.
2578 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2580 # Show the desired vars with dumplex().
2581 my $savout = select($OUT);
2583 # Have dumplex dump the lexicals.
2584 dumpvar::dumplex( $_, $h->{$_},
2585 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
2592 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2594 All of the commands below this point don't work after the program being
2595 debugged has ended. All of them check to see if the program has ended; this
2596 allows the commands to be relocated without worrying about a 'line of
2597 demarcation' above which commands can be entered anytime, and below which
2600 =head4 C<n> - single step, but don't trace down into subs
2602 Done by setting C<$single> to 2, which forces subs to execute straight through
2603 when entered (see X<DB::sub>). We also save the C<n> command in C<$laststep>,
2604 so a null command knows what to re-execute.
2609 $cmd =~ /^n$/ && do {
2610 end_report(), next CMD if $finished and $level <= 1;
2612 # Single step, but don't enter subs.
2615 # Save for empty command (repeat last).
2620 =head4 C<s> - single-step, entering subs
2622 Sets C<$single> to 1, which causes X<DB::sub> to continue tracing inside
2623 subs. Also saves C<s> as C<$lastcmd>.
2628 $cmd =~ /^s$/ && do {
2630 # Get out and restart the command loop if program
2632 end_report(), next CMD if $finished and $level <= 1;
2634 # Single step should enter subs.
2637 # Save for empty command (repeat last).
2642 =head4 C<c> - run continuously, setting an optional breakpoint
2644 Most of the code for this command is taken up with locating the optional
2645 breakpoint, which is either a subroutine name or a line number. We set
2646 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2647 in this and all call levels above this one.
2651 # c - start continuous execution.
2652 $cmd =~ /^c\b\s*([\w:]*)\s*$/ && do {
2654 # Hey, show's over. The debugged program finished
2655 # executing already.
2656 end_report(), next CMD if $finished and $level <= 1;
2658 # Capture the place to put a one-time break.
2661 # Probably not needed, since we finish an interactive
2662 # sub-session anyway...
2663 # local $filename = $filename;
2664 # local *dbline = *dbline; # XXX Would this work?!
2666 # The above question wonders if localizing the alias
2667 # to the magic array works or not. Since it's commented
2668 # out, we'll just leave that to speculation for now.
2670 # If the "subname" isn't all digits, we'll assume it
2671 # is a subroutine name, and try to find it.
2672 if ( $subname =~ /\D/ ) { # subroutine name
2673 # Qualify it to the current package unless it's
2674 # already qualified.
2675 $subname = $package . "::" . $subname
2676 unless $subname =~ /::/;
2678 # find_sub will return "file:line_number" corresponding
2679 # to where the subroutine is defined; we call find_sub,
2680 # break up the return value, and assign it in one
2682 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2684 # Force the line number to be numeric.
2687 # If we got a line number, we found the sub.
2690 # Switch all the debugger's internals around so
2691 # we're actually working with that file.
2693 *dbline = $main::{ '_<' . $filename };
2695 # Mark that there's a breakpoint in this file.
2696 $had_breakpoints{$filename} |= 1;
2698 # Scan forward to the first executable line
2699 # after the 'sub whatever' line.
2701 ++$i while $dbline[$i] == 0 && $i < $max;
2704 # We didn't find a sub by that name.
2706 print $OUT "Subroutine $subname not found.\n";
2709 } ## end if ($subname =~ /\D/)
2711 # At this point, either the subname was all digits (an
2712 # absolute line-break request) or we've scanned through
2713 # the code following the definition of the sub, looking
2714 # for an executable, which we may or may not have found.
2716 # If $i (which we set $subname from) is non-zero, we
2717 # got a request to break at some line somewhere. On
2718 # one hand, if there wasn't any real subroutine name
2719 # involved, this will be a request to break in the current
2720 # file at the specified line, so we have to check to make
2721 # sure that the line specified really is breakable.
2723 # On the other hand, if there was a subname supplied, the
2724 # preceeding block has moved us to the proper file and
2725 # location within that file, and then scanned forward
2726 # looking for the next executable line. We have to make
2727 # sure that one was found.
2729 # On the gripping hand, we can't do anything unless the
2730 # current value of $i points to a valid breakable line.
2735 if ( $dbline[$i] == 0 ) {
2736 print $OUT "Line $i not breakable.\n";
2740 # Yes. Set up the one-time-break sigil.
2741 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2744 # Turn off stack tracing from here up.
2745 for ( $i = 0 ; $i <= $stack_depth ; ) {
2746 $stack[ $i++ ] &= ~1;
2751 =head4 C<r> - return from a subroutine
2753 For C<r> to work properly, the debugger has to stop execution again
2754 immediately after the return is executed. This is done by forcing
2755 single-stepping to be on in the call level above the current one. If
2756 we are printing return values when a C<r> is executed, set C<$doret>
2757 appropriately, and force us out of the command loop.
2761 # r - return from the current subroutine.
2762 $cmd =~ /^r$/ && do {
2764 # Can't do anythign if the program's over.
2765 end_report(), next CMD if $finished and $level <= 1;
2767 # Turn on stack trace.
2768 $stack[$stack_depth] |= 1;
2770 # Print return value unless the stack is empty.
2771 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2775 =head4 C<T> - stack trace
2777 Just calls C<DB::print_trace>.
2781 $cmd =~ /^T$/ && do {
2782 print_trace( $OUT, 1 ); # skip DB
2786 =head4 C<w> - List window around current line.
2788 Just calls C<DB::cmd_w>.
2792 $cmd =~ /^w\b\s*(.*)/s && do { &cmd_w( 'w', $1 ); next CMD; };
2794 =head4 C<W> - watch-expression processing.
2796 Just calls C<DB::cmd_W>.
2800 $cmd =~ /^W\b\s*(.*)/s && do { &cmd_W( 'W', $1 ); next CMD; };
2802 =head4 C</> - search forward for a string in the source
2804 We take the argument and treat it as a pattern. If it turns out to be a
2805 bad one, we return the error we got from trying to C<eval> it and exit.
2806 If not, we create some code to do the search and C<eval> it so it can't
2811 $cmd =~ /^\/(.*)$/ && do {
2813 # The pattern as a string.
2816 # Remove the final slash.
2817 $inpat =~ s:([^\\])/$:$1:;
2819 # If the pattern isn't null ...
2820 if ( $inpat ne "" ) {
2822 # Turn of warn and die procesing for a bit.
2823 local $SIG{__DIE__};
2824 local $SIG{__WARN__};
2826 # Create the pattern.
2827 eval '$inpat =~ m' . "\a$inpat\a";
2830 # Oops. Bad pattern. No biscuit.
2831 # Print the eval error and go back for more
2837 } ## end if ($inpat ne "")
2839 # Set up to stop on wrap-around.
2842 # Don't move off the current line.
2845 # Done in eval so nothing breaks if the pattern
2846 # does something weird.
2849 # Move ahead one line.
2852 # Wrap if we pass the last line.
2853 $start = 1 if ($start > $max);
2855 # Stop if we have gotten back to this line again,
2856 last if ($start == $end);
2858 # A hit! (Note, though, that we are doing
2859 # case-insensitive matching. Maybe a qr//
2860 # expression would be better, so the user could
2861 # do case-sensitive matching if desired.
2862 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2863 if ($slave_editor) {
2864 # Handle proper escaping in the slave.
2865 print $OUT "\032\032$filename:$start:0\n";
2868 # Just print the line normally.
2869 print $OUT "$start:\t",$dbline[$start],"\n";
2871 # And quit since we found something.
2876 # If we wrapped, there never was a match.
2877 print $OUT "/$pat/: not found\n" if ( $start == $end );
2881 =head4 C<?> - search backward for a string in the source
2883 Same as for C</>, except the loop runs backwards.
2887 # ? - backward pattern search.
2888 $cmd =~ /^\?(.*)$/ && do {
2890 # Get the pattern, remove trailing question mark.
2892 $inpat =~ s:([^\\])\?$:$1:;
2894 # If we've got one ...
2895 if ( $inpat ne "" ) {
2897 # Turn off die & warn handlers.
2898 local $SIG{__DIE__};
2899 local $SIG{__WARN__};
2900 eval '$inpat =~ m' . "\a$inpat\a";
2904 # Ouch. Not good. Print the error.
2909 } ## end if ($inpat ne "")
2911 # Where we are now is where to stop after wraparound.
2914 # Don't move away from this line.
2917 # Search inside the eval to prevent pattern badness
2924 # Wrap if we pass the first line.
2926 $start = $max if ($start <= 0);
2928 # Quit if we get back where we started,
2929 last if ($start == $end);
2932 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2933 if ($slave_editor) {
2934 # Yep, follow slave editor requirements.
2935 print $OUT "\032\032$filename:$start:0\n";
2938 # Yep, just print normally.
2939 print $OUT "$start:\t",$dbline[$start],"\n";
2947 # Say we failed if the loop never found anything,
2948 print $OUT "?$pat?: not found\n" if ( $start == $end );
2952 =head4 C<$rc> - Recall command
2954 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2955 that the terminal supports history). It find the the command required, puts it
2956 into C<$cmd>, and redoes the loop to execute it.
2960 # $rc - recall command.
2961 $cmd =~ /^$rc+\s*(-)?(\d+)?$/ && do {
2963 # No arguments, take one thing off history.
2964 pop(@hist) if length($cmd) > 1;
2966 # Relative (- found)?
2967 # Y - index back from most recent (by 1 if bare minus)
2968 # N - go to that particular command slot or the last
2969 # thing if nothing following.
2970 $i = $1 ? ( $#hist - ( $2 || 1 ) ) : ( $2 || $#hist );
2972 # Pick out the command desired.
2975 # Print the command to be executed and restart the loop
2976 # with that command in the buffer.
2977 print $OUT $cmd, "\n";
2981 =head4 C<$sh$sh> - C<system()> command
2983 Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
2984 C<STDOUT> from getting messed up.
2988 # $sh$sh - run a shell command (if it's all ASCII).
2989 # Can't run shell commands with Unicode in the debugger, hmm.
2990 $cmd =~ /^$sh$sh\s*([\x00-\xff]*)/ && do {
2997 =head4 C<$rc I<pattern> $rc> - Search command history
2999 Another command to manipulate C<@hist>: this one searches it with a pattern.
3000 If a command is found, it is placed in C<$cmd> and executed via <redo>.
3004 # $rc pattern $rc - find a command in the history.
3005 $cmd =~ /^$rc([^$rc].*)$/ && do {
3007 # Create the pattern to use.
3010 # Toss off last entry if length is >1 (and it always is).
3011 pop(@hist) if length($cmd) > 1;
3013 # Look backward through the history.
3014 for ( $i = $#hist ; $i ; --$i ) {
3016 # Stop if we find it.
3017 last if $hist[$i] =~ /$pat/;
3023 print $OUT "No such command!\n\n";
3027 # Found it. Put it in the buffer, print it, and process it.
3029 print $OUT $cmd, "\n";
3033 =head4 C<$sh> - Invoke a shell
3035 Uses C<DB::system> to invoke a shell.
3039 # $sh - start a shell.
3040 $cmd =~ /^$sh$/ && do {
3042 # Run the user's shell. If none defined, run Bourne.
3043 # We resume execution when the shell terminates.
3044 &system( $ENV{SHELL} || "/bin/sh" );
3048 =head4 C<$sh I<command>> - Force execution of a command in a shell
3050 Like the above, but the command is passed to the shell. Again, we use
3051 C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
3055 # $sh command - start a shell and run a command in it.
3056 $cmd =~ /^$sh\s*([\x00-\xff]*)/ && do {
3058 # XXX: using csh or tcsh destroys sigint retvals!
3059 #&system($1); # use this instead
3061 # use the user's shell, or Bourne if none defined.
3062 &system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3066 =head4 C<H> - display commands in history
3068 Prints the contents of C<@hist> (if any).
3072 $cmd =~ /^H\b\s*\*/ && do {
3073 @hist = @truehist = ();
3074 print $OUT "History cleansed\n";
3078 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
3080 # Anything other than negative numbers is ignored by
3081 # the (incorrect) pattern, so this test does nothing.
3082 $end = $2 ? ( $#hist - $2 ) : 0;
3084 # Set to the minimum if less than zero.
3085 $hist = 0 if $hist < 0;
3087 # Start at the end of the array.
3088 # Stay in while we're still above the ending value.
3089 # Tick back by one each time around the loop.
3090 for ( $i = $#hist ; $i > $end ; $i-- ) {
3092 # Print the command unless it has no arguments.
3093 print $OUT "$i: ", $hist[$i], "\n"
3094 unless $hist[$i] =~ /^.?$/;
3099 =head4 C<man, doc, perldoc> - look up documentation
3101 Just calls C<runman()> to print the appropriate document.
3105 # man, perldoc, doc - show manual pages.
3106 $cmd =~ /^(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?$/ && do {
3113 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3114 the bottom of the loop.
3118 # p - print (no args): print $_.
3119 $cmd =~ s/^p$/print {\$DB::OUT} \$_/;
3121 # p - print the given expression.
3122 $cmd =~ s/^p\b/print {\$DB::OUT} /;
3124 =head4 C<=> - define command alias
3126 Manipulates C<%alias> to add or list command aliases.
3130 # = - set up a command alias.
3131 $cmd =~ s/^=\s*// && do {
3133 if ( length $cmd == 0 ) {
3135 # No args, get current aliases.
3136 @keys = sort keys %alias;
3138 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3140 # Creating a new alias. $k is alias name, $v is
3143 # can't use $_ or kill //g state
3144 for my $x ( $k, $v ) {
3146 # Escape "alarm" characters.
3150 # Substitute key for value, using alarm chars
3151 # as separators (which is why we escaped them in
3153 $alias{$k} = "s\a$k\a$v\a";
3155 # Turn off standard warn and die behavior.
3156 local $SIG{__DIE__};
3157 local $SIG{__WARN__};
3160 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3162 # Nope. Bad alias. Say so and get out.
3163 print $OUT "Can't alias $k to $v: $@\n";
3168 # We'll only list the new one.
3170 } ## end elsif (my ($k, $v) = ($cmd...
3172 # The argument is the alias to list.
3180 # Messy metaquoting: Trim the substiution code off.
3181 # We use control-G as the delimiter because it's not
3182 # likely to appear in the alias.
3183 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3186 print $OUT "$k\t= $1\n";
3188 elsif ( defined $alias{$k} ) {
3190 # Couldn't trim it off; just print the alias code.
3191 print $OUT "$k\t$alias{$k}\n";
3196 print "No alias for $k\n";
3198 } ## end for my $k (@keys)
3202 =head4 C<source> - read commands from a file.
3204 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3209 # source - read commands from a file (or pipe!) and execute.
3210 $cmd =~ /^source\s+(.*\S)/ && do {
3211 if ( open my $fh, $1 ) {
3213 # Opened OK; stick it in the list of file handles.
3219 &warn("Can't execute `$1': $!\n");
3224 =head4 C<save> - send current history to a file
3226 Takes the complete history, (not the shrunken version you see with C<H>),
3227 and saves it to the given filename, so it can be replayed using C<source>.
3229 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3233 # save source - write commands to a file for later use
3234 $cmd =~ /^save\s*(.*)$/ && do {
3235 my $file = $1 || '.perl5dbrc'; # default?
3236 if ( open my $fh, "> $file" ) {
3238 # chomp to remove extraneous newlines from source'd files
3239 chomp( my @truelist =
3240 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3242 print $fh join( "\n", @truelist );
3243 print "commands saved in $file\n";
3246 &warn("Can't save debugger commands in '$1': $!\n");
3251 =head4 C<R> - restart
3253 Restart the debugger session.
3255 =head4 C<rerun> - rerun the current session
3257 Return to any given position in the B<true>-history list
3261 # R - restart execution.
3262 # rerun - controlled restart execution.
3263 $cmd =~ /^(R|rerun\s*(.*))$/ && do {
3264 my @args = ($1 eq 'R' ? restart() : rerun($2));
3266 # Close all non-system fds for a clean restart. A more
3267 # correct method would be to close all fds that were not
3268 # open when the process started, but this seems to be
3269 # hard. See "debugger 'R'estart and open database
3270 # connections" on p5p.
3272 my $max_fd = 1024; # default if POSIX can't be loaded
3273 if (eval { require POSIX }) {
3274 $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX());
3277 if (defined $max_fd) {
3278 foreach ($^F+1 .. $max_fd-1) {
3279 next unless open FD_TO_CLOSE, "<&=$_";
3284 # And run Perl again. We use exec() to keep the
3285 # PID stable (and that way $ini_pids is still valid).
3286 exec(@args) || print $OUT "exec failed: $!\n";
3291 =head4 C<|, ||> - pipe output through the pager.
3293 FOR C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3294 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3295 pipe to the pager (restoring the output filehandles if this fails). If this
3296 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3297 set C<$signal>, sending us back into the debugger.
3299 We then trim off the pipe symbols and C<redo> the command loop at the
3300 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3305 # || - run command in the pager, with output to DB::OUT.
3306 $cmd =~ /^\|\|?\s*[^|]/ && do {
3307 if ( $pager =~ /^\|/ ) {
3309 # Default pager is into a pipe. Redirect I/O.
3310 open( SAVEOUT, ">&STDOUT" )
3311 || &warn("Can't save STDOUT");
3312 open( STDOUT, ">&OUT" )
3313 || &warn("Can't redirect STDOUT");
3314 } ## end if ($pager =~ /^\|/)
3317 # Not into a pipe. STDOUT is safe.
3318 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3321 # Fix up environment to record we have less if so.
3324 unless ( $piped = open( OUT, $pager ) ) {
3326 # Couldn't open pipe to pager.
3327 &warn("Can't pipe output to `$pager'");
3328 if ( $pager =~ /^\|/ ) {
3330 # Redirect I/O back again.
3331 open( OUT, ">&STDOUT" ) # XXX: lost message
3332 || &warn("Can't restore DB::OUT");
3333 open( STDOUT, ">&SAVEOUT" )
3334 || &warn("Can't restore STDOUT");
3336 } ## end if ($pager =~ /^\|/)
3339 # Redirect I/O. STDOUT already safe.
3340 open( OUT, ">&STDOUT" ) # XXX: lost message
3341 || &warn("Can't restore DB::OUT");
3344 } ## end unless ($piped = open(OUT,...
3346 # Set up broken-pipe handler if necessary.
3347 $SIG{PIPE} = \&DB::catch
3349 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
3351 # Save current filehandle, unbuffer out, and put it back.
3352 $selected = select(OUT);
3355 # Don't put it back if pager was a pipe.
3356 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
3358 # Trim off the pipe symbols and run the command now.
3359 $cmd =~ s/^\|+\s*//;
3363 =head3 END OF COMMAND PARSING
3365 Anything left in C<$cmd> at this point is a Perl expression that we want to
3366 evaluate. We'll always evaluate in the user's context, and fully qualify
3367 any variables we might want to address in the C<DB> package.
3371 # t - turn trace on.
3372 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3374 # s - single-step. Remember the last command was 's'.
3375 $cmd =~ s/^s\s/\$DB::single = 1;\n/ && do { $laststep = 's' };
3377 # n - single-step, but not into subs. Remember last command
3379 $cmd =~ s/^n\s/\$DB::single = 2;\n/ && do { $laststep = 'n' };
3383 # Make sure the flag that says "the debugger's running" is
3384 # still on, to make sure we get control again.
3385 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3387 # Run *our* eval that executes in the caller's context.
3390 # Turn off the one-time-dump stuff now.
3392 $onetimeDump = undef;
3393 $onetimedumpDepth = undef;
3395 elsif ( $term_pid == $$ ) {
3399 # XXX If this is the master pid, print a newline.
3402 } ## end while (($term || &setterm...
3404 =head3 POST-COMMAND PROCESSING
3406 After each command, we check to see if the command output was piped anywhere.
3407 If so, we go through the necessary code to unhook the pipe and go back to
3408 our standard filehandles for input and output.
3414 # At the end of every command:
3417 # Unhook the pipe mechanism now.
3418 if ( $pager =~ /^\|/ ) {
3420 # No error from the child.
3423 # we cannot warn here: the handle is missing --tchrist
3424 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
3426 # most of the $? crud was coping with broken cshisms
3427 # $? is explicitly set to 0, so this never runs.
3429 print SAVEOUT "Pager `$pager' failed: ";
3431 print SAVEOUT "shell returned -1\n";
3434 print SAVEOUT ( $? & 127 )
3435 ? " (SIG#" . ( $? & 127 ) . ")"
3436 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3439 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3443 # Reopen filehandle for our output (if we can) and
3444 # restore STDOUT (if we can).
3445 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3446 open( STDOUT, ">&SAVEOUT" )
3447 || &warn("Can't restore STDOUT");
3449 # Turn off pipe exception handler if necessary.
3450 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
3452 # Will stop ignoring SIGPIPE if done like nohup(1)
3453 # does SIGINT but Perl doesn't give us a choice.
3454 } ## end if ($pager =~ /^\|/)
3457 # Non-piped "pager". Just restore STDOUT.
3458 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3461 # Close filehandle pager was using, restore the normal one
3464 select($selected), $selected = "" unless $selected eq "";
3468 } ## end if ($piped)
3471 =head3 COMMAND LOOP TERMINATION
3473 When commands have finished executing, we come here. If the user closed the
3474 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3475 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3476 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3477 The interpreter will then execute the next line and then return control to us
3482 # No more commands? Quit.
3483 $fall_off_end = 1 unless defined $cmd; # Emulate `q' on EOF
3485 # Evaluate post-prompt commands.
3486 foreach $evalarg (@$post) {
3489 } # if ($single || $signal)
3491 # Put the user's globals back where you found them.
3492 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3496 # The following code may be executed now:
3501 C<sub> is called whenever a subroutine call happens in the program being
3502 debugged. The variable C<$DB::sub> contains the name of the subroutine
3505 The core function of this subroutine is to actually call the sub in the proper
3506 context, capturing its output. This of course causes C<DB::DB> to get called
3507 again, repeating until the subroutine ends and returns control to C<DB::sub>
3508 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3509 return value, and returns its captured copy of the return value as its own
3510 return value. The value then feeds back into the program being debugged as if
3511 C<DB::sub> hadn't been there at all.
3513 C<sub> does all the work of printing the subroutine entry and exit messages
3514 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3515 and also prints the return value if needed (for the C<r> command and if
3516 the 16 bit is set in C<$frame>).
3518 It also tracks the subroutine call depth by saving the current setting of
3519 C<$single> in the C<@stack> package global; if this exceeds the value in
3520 C<$deep>, C<sub> automatically turns on printing of the current depth by
3521 setting the 4 bit in C<$single>. In any case, it keeps the current setting
3522 of stop/don't stop on entry to subs set as it currently is set.
3524 =head3 C<caller()> support
3526 If C<caller()> is called from the package C<DB>, it provides some
3527 additional data, in the following order:
3533 The package name the sub was in
3535 =item * C<$filename>
3537 The filename it was defined in
3541 The line number it was defined on
3543 =item * C<$subroutine>
3545 The subroutine name; C<'(eval)'> if an C<eval>().
3549 1 if it has arguments, 0 if not
3551 =item * C<$wantarray>
3553 1 if array context, 0 if scalar context
3555 =item * C<$evaltext>
3557 The C<eval>() text, if any (undefined for C<eval BLOCK>)
3559 =item * C<$is_require>
3561 frame was created by a C<use> or C<require> statement
3565 pragma information; subject to change between versions
3569 pragma information: subject to change between versions
3571 =item * C<@DB::args>
3573 arguments with which the subroutine was invoked
3581 # lock ourselves under threads
3584 # Whether or not the autoloader was running, a scalar to put the
3585 # sub's return value in (if needed), and an array to put the sub's
3586 # return value in (if needed).
3587 my ( $al, $ret, @ret ) = "";
3588 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
3589 print "creating new thread\n";
3592 # If the last ten characters are C'::AUTOLOAD', note we've traced
3593 # into AUTOLOAD for $sub.
3594 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3598 # We stack the stack pointer and then increment it to protect us
3599 # from a situation that might unwind a whole bunch of call frames
3600 # at once. Localizing the stack pointer means that it will automatically
3601 # unwind the same amount when multiple stack frames are unwound.
3602 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3605 $#stack = $stack_depth;
3607 # Save current single-step setting.
3608 $stack[-1] = $single;
3610 # Turn off all flags except single-stepping.
3613 # If we've gotten really deeply recursed, turn on the flag that will
3614 # make us stop with the 'deep recursion' message.
3615 $single |= 4 if $stack_depth == $deep;
3617 # If frame messages are on ...
3619 $frame & 4 # Extended frame entry message
3621 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3623 # Why -1? But it works! :-(
3624 # Because print_trace will call add 1 to it and then call
3625 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3627 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3629 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3631 # standard frame entry message
3635 # Determine the sub's return type,and capture approppriately.
3638 # Called in array context. call sub and capture output.
3639 # DB::DB will recursively get control again if appropriate; we'll come
3640 # back here when the sub is finished.
3643 eval { @ret = &$sub; };
3646 $signal = 1 unless $warnassertions;
3653 # Pop the single-step value back off the stack.
3654 $single |= $stack[ $stack_depth-- ];
3656 # Check for exit trace messages...
3658 $frame & 4 # Extended exit message
3660 print_lineinfo( ' ' x $stack_depth, "out " ),
3661 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3663 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3665 # Standard exit message
3669 # Print the return info if we need to.
3670 if ( $doret eq $stack_depth or $frame & 16 ) {
3672 # Turn off output record separator.
3674 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3676 # Indent if we're printing because of $frame tracing.
3677 print $fh ' ' x $stack_depth if $frame & 16;
3679 # Print the return value.
3680 print $fh "list context return from $sub:\n";
3681 dumpit( $fh, \@ret );
3683 # And don't print it again.
3685 } ## end if ($doret eq $stack_depth...
3686 # And we have to return the return value now.
3688 } ## end if (wantarray)
3696 # Save the value if it's wanted at all.
3701 $signal = 1 unless $warnassertions;
3703 $ret = undef unless defined wantarray;
3706 if ( defined wantarray ) {
3708 # Save the value if it's wanted at all.
3713 # Void return, explicitly.
3719 # Pop the single-step value off the stack.
3720 $single |= $stack[ $stack_depth-- ];
3722 # If we're doing exit messages...
3724 $frame & 4 # Extended messsages
3726 print_lineinfo( ' ' x $stack_depth, "out " ),
3727 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3729 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3735 # If we are supposed to show the return value... same as before.
3736 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
3738 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3739 print $fh ( ' ' x $stack_depth ) if $frame & 16;
3742 ? "scalar context return from $sub: "
3743 : "void context return from $sub\n"
3745 dumpit( $fh, $ret ) if defined wantarray;
3747 } ## end if ($doret eq $stack_depth...
3749 # Return the appropriate scalar value.
3751 } ## end else [ if (wantarray)
3754 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
3756 In Perl 5.8.0, there was a major realignment of the commands and what they did,
3757 Most of the changes were to systematize the command structure and to eliminate
3758 commands that threw away user input without checking.
3760 The following sections describe the code added to make it easy to support
3761 multiple command sets with conflicting command names. This section is a start
3762 at unifying all command processing to make it simpler to develop commands.
3764 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
3765 number, and C<$dbline> (the current line) as arguments.
3767 Support functions in this section which have multiple modes of failure C<die>
3768 on error; the rest simply return a false value.
3770 The user-interface functions (all of the C<cmd_*> functions) just output
3775 The C<%set> hash defines the mapping from command letter to subroutine
3778 C<%set> is a two-level hash, indexed by set name and then by command name.
3779 Note that trying to set the CommandSet to 'foobar' simply results in the
3780 5.8.0 command set being used, since there's no top-level entry for 'foobar'.
3789 'A' => 'pre580_null',
3791 'B' => 'pre580_null',
3792 'd' => 'pre580_null',
3795 'M' => 'pre580_null',
3797 'o' => 'pre580_null',
3803 '<' => 'pre590_prepost',
3804 '<<' => 'pre590_prepost',
3805 '>' => 'pre590_prepost',
3806 '>>' => 'pre590_prepost',
3807 '{' => 'pre590_prepost',
3808 '{{' => 'pre590_prepost',
3812 =head2 C<cmd_wrapper()> (API)
3814 C<cmd_wrapper()> allows the debugger to switch command sets
3815 depending on the value of the C<CommandSet> option.
3817 It tries to look up the command in the X<C<%set>> package-level I<lexical>
3818 (which means external entities can't fiddle with it) and create the name of
3819 the sub to call based on the value found in the hash (if it's there). I<All>
3820 of the commands to be handled in a set have to be added to C<%set>; if they
3821 aren't found, the 5.8.0 equivalent is called (if there is one).
3823 This code uses symbolic references.
3830 my $dblineno = shift;
3832 # Assemble the command subroutine's name by looking up the
3833 # command set and command name in %set. If we can't find it,
3834 # default to the older version of the command.
3836 . ( $set{$CommandSet}{$cmd}
3837 || ( $cmd =~ /^[<>{]+/o ? 'prepost' : $cmd ) );
3839 # Call the command subroutine, call it by name.
3840 return &$call( $cmd, $line, $dblineno );
3841 } ## end sub cmd_wrapper
3843 =head3 C<cmd_a> (command)
3845 The C<a> command handles pre-execution actions. These are associated with a
3846 particular line, so they're stored in C<%dbline>. We default to the current
3847 line if none is specified.
3853 my $line = shift || ''; # [.|line] expr
3856 # If it's dot (here), or not all digits, use the current line.
3857 $line =~ s/^(\.|(?:[^\d]))/$dbline/;
3859 # Should be a line number followed by an expression.
3860 if ( $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
3861 my ( $lineno, $expr ) = ( $1, $2 );
3863 # If we have an expression ...
3864 if ( length $expr ) {
3866 # ... but the line isn't breakable, complain.
3867 if ( $dbline[$lineno] == 0 ) {
3869 "Line $lineno($dbline[$lineno]) does not have an action?\n";
3873 # It's executable. Record that the line has an action.
3874 $had_breakpoints{$filename} |= 2;
3876 # Remove any action, temp breakpoint, etc.
3877 $dbline{$lineno} =~ s/\0[^\0]*//;
3879 # Add the action to the line.
3880 $dbline{$lineno} .= "\0" . action($expr);
3882 } ## end if (length $expr)
3883 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
3888 "Adding an action requires an optional lineno and an expression\n"
3893 =head3 C<cmd_A> (command)
3895 Delete actions. Similar to above, except the delete code is in a separate
3896 subroutine, C<delete_action>.
3902 my $line = shift || '';
3906 $line =~ s/^\./$dbline/;
3908 # Call delete_action with a null param to delete them all.
3909 # The '1' forces the eval to be true. It'll be false only
3910 # if delete_action blows up for some reason, in which case
3911 # we print $@ and get out.
3912 if ( $line eq '*' ) {
3913 eval { &delete_action(); 1 } or print $OUT $@ and return;
3916 # There's a real line number. Pass it to delete_action.
3917 # Error trapping is as above.
3918 elsif ( $line =~ /^(\S.*)/ ) {
3919 eval { &delete_action($1); 1 } or print $OUT $@ and return;
3922 # Swing and a miss. Bad syntax.
3925 "Deleting an action requires a line number, or '*' for all\n" ; # hint
3929 =head3 C<delete_action> (API)
3931 C<delete_action> accepts either a line number or C<undef>. If a line number
3932 is specified, we check for the line being executable (if it's not, it
3933 couldn't have had an action). If it is, we just take the action off (this
3934 will get any kind of an action, including breakpoints).
3940 if ( defined($i) ) {
3943 die "Line $i has no action .\n" if $dbline[$i] == 0;
3945 # Nuke whatever's there.
3946 $dbline{$i} =~ s/\0[^\0]*//; # \^a
3947 delete $dbline{$i} if $dbline{$i} eq '';
3950 print $OUT "Deleting all actions...\n";
3951 for my $file ( keys %had_breakpoints ) {
3952 local *dbline = $main::{ '_<' . $file };
3955 for ( $i = 1 ; $i <= $max ; $i++ ) {
3956 if ( defined $dbline{$i} ) {
3957 $dbline{$i} =~ s/\0[^\0]*//;
3958 delete $dbline{$i} if $dbline{$i} eq '';
3960 unless ( $had_breakpoints{$file} &= ~2 ) {
3961 delete $had_breakpoints{$file};
3963 } ## end for ($i = 1 ; $i <= $max...
3964 } ## end for my $file (keys %had_breakpoints)
3965 } ## end else [ if (defined($i))
3966 } ## end sub delete_action
3968 =head3 C<cmd_b> (command)
3970 Set breakpoints. Since breakpoints can be set in so many places, in so many
3971 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
3972 we try to parse the command type, and then shuttle it off to an appropriate
3973 subroutine to actually do the work of setting the breakpoint in the right
3980 my $line = shift; # [.|line] [cond]
3983 # Make . the current line number if it's there..
3984 $line =~ s/^\./$dbline/;
3986 # No line number, no condition. Simple break on current line.
3987 if ( $line =~ /^\s*$/ ) {
3988 &cmd_b_line( $dbline, 1 );
3991 # Break on load for a file.
3992 elsif ( $line =~ /^load\b\s*(.*)/ ) {
3998 # b compile|postpone <some sub> [<condition>]
3999 # The interpreter actually traps this one for us; we just put the
4000 # necessary condition in the %postponed hash.
4001 elsif ( $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4003 # Capture the condition if there is one. Make it true if none.
4004 my $cond = length $3 ? $3 : '1';
4006 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
4007 # if it was 'compile'.
4008 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
4010 # De-Perl4-ify the name - ' separators to ::.
4011 $subname =~ s/\'/::/g;
4013 # Qualify it into the current package unless it's already qualified.
4014 $subname = "${'package'}::" . $subname unless $subname =~ /::/;
4016 # Add main if it starts with ::.
4017 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4019 # Save the break type for this sub.
4020 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
4021 } ## end elsif ($line =~ ...
4023 # b <sub name> [<condition>]
4024 elsif ( $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4028 $cond = length $2 ? $2 : '1';
4029 &cmd_b_sub( $subname, $cond );
4032 # b <line> [<condition>].
4033 elsif ( $line =~ /^(\d*)\s*(.*)/ ) {
4035 # Capture the line. If none, it's the current line.
4036 $line = $1 || $dbline;
4038 # If there's no condition, make it '1'.
4039 $cond = length $2 ? $2 : '1';
4042 &cmd_b_line( $line, $cond );
4045 # Line didn't make sense.
4047 print "confused by line($line)?\n";
4051 =head3 C<break_on_load> (API)
4053 We want to break when this file is loaded. Mark this file in the
4054 C<%break_on_load> hash, and note that it has a breakpoint in
4055 C<%had_breakpoints>.
4061 $break_on_load{$file} = 1;
4062 $had_breakpoints{$file} |= 1;
4065 =head3 C<report_break_on_load> (API)
4067 Gives us an array of filenames that are set to break on load. Note that
4068 only files with break-on-load are in here, so simply showing the keys
4073 sub report_break_on_load {
4074 sort keys %break_on_load;
4077 =head3 C<cmd_b_load> (command)
4079 We take the file passed in and try to find it in C<%INC> (which maps modules
4080 to files they came from). We mark those files for break-on-load via
4081 C<break_on_load> and then report that it was done.
4089 # This is a block because that way we can use a redo inside it
4090 # even without there being any looping structure at all outside it.
4093 # Save short name and full path if found.
4095 push @files, $::INC{$file} if $::INC{$file};
4097 # Tack on .pm and do it again unless there was a '.' in the name
4099 $file .= '.pm', redo unless $file =~ /\./;
4102 # Do the real work here.
4103 break_on_load($_) for @files;
4105 # All the files that have break-on-load breakpoints.
4106 @files = report_break_on_load;
4108 # Normalize for the purposes of our printing this.
4111 print $OUT "Will stop on load of `@files'.\n";
4112 } ## end sub cmd_b_load
4114 =head3 C<$filename_error> (API package global)
4116 Several of the functions we need to implement in the API need to work both
4117 on the current file and on other files. We don't want to duplicate code, so
4118 C<$filename_error> is used to contain the name of the file that's being
4119 worked on (if it's not the current one).
4121 We can now build functions in pairs: the basic function works on the current
4122 file, and uses C<$filename_error> as part of its error message. Since this is
4123 initialized to C<''>, no filename will appear when we are working on the
4126 The second function is a wrapper which does the following:
4130 =item * Localizes C<$filename_error> and sets it to the name of the file to be processed.
4132 =item * Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4134 =item * Calls the first function.
4136 The first function works on the "current" (i.e., the one we changed to) file,
4137 and prints C<$filename_error> in the error message (the name of the other file)
4138 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
4139 restored to C<''>. This restores everything to the way it was before the
4140 second function was called at all.
4142 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4149 $filename_error = '';
4151 =head3 breakable_line($from, $to) (API)
4153 The subroutine decides whether or not a line in the current file is breakable.
4154 It walks through C<@dbline> within the range of lines specified, looking for
4155 the first line that is breakable.
4157 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4158 first line I<after> C<$to> that's breakable, if there is one.
4160 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4161 first line I<before> C<$to> that's breakable, if there is one.
4165 sub breakable_line {
4167 my ( $from, $to ) = @_;
4169 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4172 # If there are at least 2 arguments, we're trying to search a range.
4175 # $delta is positive for a forward search, negative for a backward one.
4176 my $delta = $from < $to ? +1 : -1;
4178 # Keep us from running off the ends of the file.
4179 my $limit = $delta > 0 ? $#dbline : 1;
4181 # Clever test. If you're a mathematician, it's obvious why this
4182 # test works. If not:
4183 # If $delta is positive (going forward), $limit will be $#dbline.
4184 # If $to is less than $limit, ($limit - $to) will be positive, times
4185 # $delta of 1 (positive), so the result is > 0 and we should use $to
4186 # as the stopping point.
4188 # If $to is greater than $limit, ($limit - $to) is negative,
4189 # times $delta of 1 (positive), so the result is < 0 and we should
4190 # use $limit ($#dbline) as the stopping point.
4192 # If $delta is negative (going backward), $limit will be 1.
4193 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4194 # (negative) so the result is > 0, and we use $to as the stopping
4197 # If $to is less than zero, ($limit - $to) will be positive,
4198 # times $delta of -1 (negative), so the result is not > 0, and
4199 # we use $limit (1) as the stopping point.
4201 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4202 # (negative), still giving zero; the result is not > 0, and
4203 # we use $limit (1) as the stopping point.
4205 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4206 # (negative), giving a positive (>0) value, so we'll set $limit to
4209 $limit = $to if ( $limit - $to ) * $delta > 0;
4211 # The real search loop.
4212 # $i starts at $from (the point we want to start searching from).
4213 # We move through @dbline in the appropriate direction (determined
4214 # by $delta: either -1 (back) or +1 (ahead).
4215 # We stay in as long as we haven't hit an executable line
4216 # ($dbline[$i] == 0 means not executable) and we haven't reached
4217 # the limit yet (test similar to the above).
4218 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4220 } ## end if (@_ >= 2)
4222 # If $i points to a line that is executable, return that.
4223 return $i unless $dbline[$i] == 0;
4225 # Format the message and print it: no breakable lines in range.
4226 my ( $pl, $upto ) = ( '', '' );
4227 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4229 # If there's a filename in filename_error, we'll see it.
4231 die "Line$pl $from$upto$filename_error not breakable\n";
4232 } ## end sub breakable_line
4234 =head3 breakable_line_in_filename($file, $from, $to) (API)
4236 Like C<breakable_line>, but look in another file.
4240 sub breakable_line_in_filename {
4242 # Capture the file name.
4245 # Swap the magic line array over there temporarily.
4246 local *dbline = $main::{ '_<' . $f };
4248 # If there's an error, it's in this other file.
4249 local $filename_error = " of `$f'";
4251 # Find the breakable line.
4254 # *dbline and $filename_error get restored when this block ends.
4256 } ## end sub breakable_line_in_filename
4258 =head3 break_on_line(lineno, [condition]) (API)
4260 Adds a breakpoint with the specified condition (or 1 if no condition was
4261 specified) to the specified line. Dies if it can't.
4266 my ( $i, $cond ) = @_;
4268 # Always true if no condition supplied.
4269 $cond = 1 unless @_ >= 2;
4275 # Woops, not a breakable line. $filename_error allows us to say
4276 # if it was in a different file.
4277 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4279 # Mark this file as having breakpoints in it.
4280 $had_breakpoints{$filename} |= 1;
4282 # If there is an action or condition here already ...
4283 if ( $dbline{$i} ) {
4285 # ... swap this condition for the existing one.
4286 $dbline{$i} =~ s/^[^\0]*/$cond/;
4290 # Nothing here - just add the condition.
4291 $dbline{$i} = $cond;
4293 } ## end sub break_on_line
4295 =head3 cmd_b_line(line, [condition]) (command)
4297 Wrapper for C<break_on_line>. Prints the failure message if it
4303 eval { break_on_line(@_); 1 } or do {
4305 print $OUT $@ and return;
4307 } ## end sub cmd_b_line
4309 =head3 break_on_filename_line(file, line, [condition]) (API)
4311 Switches to the file specified and then calls C<break_on_line> to set
4316 sub break_on_filename_line {
4317 my ( $f, $i, $cond ) = @_;
4319 # Always true if condition left off.
4320 $cond = 1 unless @_ >= 3;
4322 # Switch the magical hash temporarily.
4323 local *dbline = $main::{ '_<' . $f };
4325 # Localize the variables that break_on_line uses to make its message.
4326 local $filename_error = " of `$f'";
4327 local $filename = $f;
4329 # Add the breakpoint.
4330 break_on_line( $i, $cond );
4331 } ## end sub break_on_filename_line
4333 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4335 Switch to another file, search the range of lines specified for an
4336 executable one, and put a breakpoint on the first one you find.
4340 sub break_on_filename_line_range {
4341 my ( $f, $from, $to, $cond ) = @_;
4343 # Find a breakable line if there is one.
4344 my $i = breakable_line_in_filename( $f, $from, $to );
4346 # Always true if missing.
4347 $cond = 1 unless @_ >= 3;
4349 # Add the breakpoint.
4350 break_on_filename_line( $f, $i, $cond );
4351 } ## end sub break_on_filename_line_range
4353 =head3 subroutine_filename_lines(subname, [condition]) (API)
4355 Search for a subroutine within a given file. The condition is ignored.
4356 Uses C<find_sub> to locate the desired subroutine.
4360 sub subroutine_filename_lines {
4361 my ( $subname, $cond ) = @_;
4363 # Returned value from find_sub() is fullpathname:startline-endline.
4364 # The match creates the list (fullpathname, start, end). Falling off
4365 # the end of the subroutine returns this implicitly.
4366 find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/;
4367 } ## end sub subroutine_filename_lines
4369 =head3 break_subroutine(subname) (API)
4371 Places a break on the first line possible in the specified subroutine. Uses
4372 C<subroutine_filename_lines> to find the subroutine, and
4373 C<break_on_filename_line_range> to place the break.
4377 sub break_subroutine {
4378 my $subname = shift;
4380 # Get filename, start, and end.
4381 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
4382 or die "Subroutine $subname not found.\n";
4384 # Null condition changes to '1' (always true).
4385 $cond = 1 unless @_ >= 2;
4387 # Put a break the first place possible in the range of lines
4388 # that make up this subroutine.
4389 break_on_filename_line_range( $file, $s, $e, @_ );
4390 } ## end sub break_subroutine
4392 =head3 cmd_b_sub(subname, [condition]) (command)
4394 We take the incoming subroutine name and fully-qualify it as best we can.
4398 =item 1. If it's already fully-qualified, leave it alone.
4400 =item 2. Try putting it in the current package.
4402 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
4404 =item 4. If it starts with '::', put it in 'main::'.
4408 After all this cleanup, we call C<break_subroutine> to try to set the
4414 my ( $subname, $cond ) = @_;
4416 # Add always-true condition if we have none.
4417 $cond = 1 unless @_ >= 2;
4419 # If the subname isn't a code reference, qualify it so that
4420 # break_subroutine() will work right.
4421 unless ( ref $subname eq 'CODE' ) {
4424 $subname =~ s/\'/::/g;
4427 # Put it in this package unless it's already qualified.
4428 $subname = "${'package'}::" . $subname
4429 unless $subname =~ /::/;
4431 # Requalify it into CORE::GLOBAL if qualifying it into this
4432 # package resulted in its not being defined, but only do so
4433 # if it really is in CORE::GLOBAL.
4434 $subname = "CORE::GLOBAL::$s"
4435 if not defined &$subname
4437 and defined &{"CORE::GLOBAL::$s"};
4439 # Put it in package 'main' if it has a leading ::.
4440 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4442 } ## end unless (ref $subname eq 'CODE')
4444 # Try to set the breakpoint.
4445 eval { break_subroutine( $subname, $cond ); 1 } or do {
4447 print $OUT $@ and return;
4449 } ## end sub cmd_b_sub
4451 =head3 C<cmd_B> - delete breakpoint(s) (command)
4453 The command mostly parses the command line and tries to turn the argument
4454 into a line spec. If it can't, it uses the current line. It then calls
4455 C<delete_breakpoint> to actually do the work.
4457 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
4458 thereby deleting all the breakpoints.
4465 # No line spec? Use dbline.
4466 # If there is one, use it if it's non-zero, or wipe it out if it is.
4467 my $line = ( $_[0] =~ /^\./ ) ? $dbline : shift || '';
4470 # If the line was dot, make the line the current one.
4471 $line =~ s/^\./$dbline/;
4473 # If it's * we're deleting all the breakpoints.
4474 if ( $line eq '*' ) {
4475 eval { &delete_breakpoint(); 1 } or print $OUT $@ and return;
4478 # If there is a line spec, delete the breakpoint on that line.
4479 elsif ( $line =~ /^(\S.*)/ ) {
4480 eval { &delete_breakpoint( $line || $dbline ); 1 } or do {
4482 print $OUT $@ and return;
4484 } ## end elsif ($line =~ /^(\S.*)/)
4489 "Deleting a breakpoint requires a line number, or '*' for all\n"
4494 =head3 delete_breakpoint([line]) (API)
4496 This actually does the work of deleting either a single breakpoint, or all
4499 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
4500 just drop out with a message saying so. If it is, we remove the condition
4501 part of the 'condition\0action' that says there's a breakpoint here. If,
4502 after we've done that, there's nothing left, we delete the corresponding
4503 line in C<%dbline> to signal that no action needs to be taken for this line.
4505 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
4506 which lists all currently-loaded files which have breakpoints. We then look
4507 at each line in each of these files, temporarily switching the C<%dbline>
4508 and C<@dbline> structures to point to the files in question, and do what
4509 we did in the single line case: delete the condition in C<@dbline>, and
4510 delete the key in C<%dbline> if nothing's left.
4512 We then wholesale delete C<%postponed>, C<%postponed_file>, and
4513 C<%break_on_load>, because these structures contain breakpoints for files
4514 and code that haven't been loaded yet. We can just kill these off because there
4515 are no magical debugger structures associated with them.
4519 sub delete_breakpoint {
4522 # If we got a line, delete just that one.
4523 if ( defined($i) ) {
4525 # Woops. This line wasn't breakable at all.
4526 die "Line $i not breakable.\n" if $dbline[$i] == 0;
4528 # Kill the condition, but leave any action.
4529 $dbline{$i} =~ s/^[^\0]*//;
4531 # Remove the entry entirely if there's no action left.
4532 delete $dbline{$i} if $dbline{$i} eq '';
4535 # No line; delete them all.
4537 print $OUT "Deleting all breakpoints...\n";
4539 # %had_breakpoints lists every file that had at least one
4541 for my $file ( keys %had_breakpoints ) {
4543 # Switch to the desired file temporarily.
4544 local *dbline = $main::{ '_<' . $file };
4549 # For all lines in this file ...
4550 for ( $i = 1 ; $i <= $max ; $i++ ) {
4552 # If there's a breakpoint or action on this line ...
4553 if ( defined $dbline{$i} ) {
4555 # ... remove the breakpoint.
4556 $dbline{$i} =~ s/^[^\0]+//;
4557 if ( $dbline{$i} =~ s/^\0?$// ) {
4559 # Remove the entry altogether if no action is there.
4562 } ## end if (defined $dbline{$i...
4563 } ## end for ($i = 1 ; $i <= $max...
4565 # If, after we turn off the "there were breakpoints in this file"
4566 # bit, the entry in %had_breakpoints for this file is zero,
4567 # we should remove this file from the hash.
4568 if ( not $had_breakpoints{$file} &= ~1 ) {
4569 delete $had_breakpoints{$file};
4571 } ## end for my $file (keys %had_breakpoints)
4573 # Kill off all the other breakpoints that are waiting for files that
4574 # haven't been loaded yet.
4576 undef %postponed_file;
4577 undef %break_on_load;
4578 } ## end else [ if (defined($i))
4579 } ## end sub delete_breakpoint
4581 =head3 cmd_stop (command)
4583 This is meant to be part of the new command API, but it isn't called or used
4584 anywhere else in the debugger. XXX It is probably meant for use in development
4589 sub cmd_stop { # As on ^C, but not signal-safy.
4593 =head3 C<cmd_e> - threads
4595 Display the current thread id:
4599 This could be how (when implemented) to send commands to this thread id (e cmd)
4600 or that thread id (e tid cmd).
4607 unless (exists($INC{'threads.pm'})) {
4608 print "threads not loaded($ENV{PERL5DB_THREADED})
4609 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4611 my $tid = threads->self->tid;
4612 print "thread id: $tid\n";
4616 =head3 C<cmd_E> - list of thread ids
4618 Display the list of available thread ids:
4622 This could be used (when implemented) to send commands to all threads (E cmd).
4629 unless (exists($INC{'threads.pm'})) {
4630 print "threads not loaded($ENV{PERL5DB_THREADED})
4631 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4633 my $tid = threads->self->tid;
4634 print "thread ids: ".join(', ',
4635 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
4640 =head3 C<cmd_h> - help command (command)
4642 Does the work of either
4646 =item * Showing all the debugger help
4648 =item * Showing help for a specific command
4657 # If we have no operand, assume null.
4658 my $line = shift || '';
4660 # 'h h'. Print the long-format help.
4661 if ( $line =~ /^h\s*/ ) {
4665 # 'h <something>'. Search for the command and print only its help.
4666 elsif ( $line =~ /^(\S.*)$/ ) {
4668 # support long commands; otherwise bogus errors
4669 # happen when you ask for h on <CR> for example
4670 my $asked = $1; # the command requested
4671 # (for proper error message)
4673 my $qasked = quotemeta($asked); # for searching; we don't
4674 # want to use it as a pattern.
4675 # XXX: finds CR but not <CR>
4677 # Search the help string for the command.
4679 $help =~ /^ # Start of a line
4681 (?:[IB]<) # Optional markup
4682 $qasked # The requested command
4687 # It's there; pull it out and print it.
4691 (?:[IB]<) # Optional markup
4692 $qasked # The command
4693 ([\s\S]*?) # Description line(s)
4694 \n) # End of last description line
4695 (?!\s) # Next line not starting with
4704 # Not found; not a debugger command.
4706 print_help("B<$asked> is not a debugger command.\n");
4708 } ## end elsif ($line =~ /^(\S.*)$/)
4710 # 'h' - print the summary help.
4712 print_help($summary);
4716 =head3 C<cmd_i> - inheritance display
4718 Display the (nested) parentage of the module or object given.
4725 eval { require Class::ISA };
4727 &warn( $@ =~ /locate/
4728 ? "Class::ISA module not found - please install\n"
4733 foreach my $isa ( split( /\s+/, $line ) ) {
4739 map { # snaffled unceremoniously from Class::ISA
4742 defined( ${"$_\::VERSION"} )
4743 ? ' ' . ${"$_\::VERSION"}
4745 } Class::ISA::self_and_super_path(ref($isa) || $isa)
4752 =head3 C<cmd_l> - list lines (command)
4754 Most of the command is taken up with transforming all the different line
4755 specification syntaxes into 'start-stop'. After that is done, the command
4756 runs a loop over C<@dbline> for the specified range of lines. It handles
4757 the printing of each line and any markers (C<==E<gt>> for current line,
4758 C<b> for break on this line, C<a> for action on this line, C<:> for this
4761 We save the last line listed in the C<$start> global for further listing
4767 my $current_line = $line;
4771 # If this is '-something', delete any spaces after the dash.
4772 $line =~ s/^-\s*$/-/;
4774 # If the line is '$something', assume this is a scalar containing a
4776 if ( $line =~ /^(\$.*)/s ) {
4778 # Set up for DB::eval() - evaluate in *user* context.
4783 # Ooops. Bad scalar.
4784 print( $OUT "Error: $@\n" ), next CMD if $@;
4786 # Good scalar. If it's a reference, find what it points to.
4788 print( $OUT "Interpreted as: $1 $s\n" );
4791 # Call self recursively to really do the command.
4793 } ## end if ($line =~ /^(\$.*)/s)
4795 # l name. Try to find a sub by that name.
4796 elsif ( $line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s ) {
4797 my $s = $subname = $1;
4800 $subname =~ s/\'/::/;
4802 # Put it in this package unless it starts with ::.
4803 $subname = $package . "::" . $subname unless $subname =~ /::/;
4805 # Put it in CORE::GLOBAL if t doesn't start with :: and
4806 # it doesn't live in this package and it lives in CORE::GLOBAL.
4807 $subname = "CORE::GLOBAL::$s"
4808 if not defined &$subname
4810 and defined &{"CORE::GLOBAL::$s"};
4812 # Put leading '::' names into 'main::'.
4813 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4815 # Get name:start-stop from find_sub, and break this up at
4817 @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
4819 # Pull off start-stop.
4820 $subrange = pop @pieces;
4822 # If the name contained colons, the split broke it up.
4823 # Put it back together.
4824 $file = join( ':', @pieces );
4826 # If we're not in that file, switch over to it.
4827 if ( $file ne $filename ) {
4828 print $OUT "Switching to file '$file'.\n"
4829 unless $slave_editor;
4831 # Switch debugger's magic structures.
4832 *dbline = $main::{ '_<' . $file };
4835 } ## end if ($file ne $filename)
4837 # Subrange is 'start-stop'. If this is less than a window full,
4838 # swap it to 'start+', which will list a window from the start point.
4840 if ( eval($subrange) < -$window ) {
4841 $subrange =~ s/-.*/+/;
4844 # Call self recursively to list the range.
4846 &cmd_l( 'l', $subrange );
4847 } ## end if ($subrange)
4851 print $OUT "Subroutine $subname not found.\n";
4853 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s)
4856 elsif ( $line =~ /^\s*$/ ) {
4858 # Compute new range to list.
4859 $incr = $window - 1;
4860 $line = $start . '-' . ( $start + $incr );
4863 &cmd_l( 'l', $line );
4866 # l [start]+number_of_lines
4867 elsif ( $line =~ /^(\d*)\+(\d*)$/ ) {
4869 # Don't reset start for 'l +nnn'.
4872 # Increment for list. Use window size if not specified.
4873 # (Allows 'l +' to work.)
4875 $incr = $window - 1 unless $incr;
4877 # Create a line range we'll understand, and recurse to do it.
4878 $line = $start . '-' . ( $start + $incr );
4879 &cmd_l( 'l', $line );
4880 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/)
4882 # l start-stop or l start,stop
4883 elsif ( $line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/ ) {
4885 # Determine end point; use end of file if not specified.
4886 $end = ( !defined $2 ) ? $max : ( $4 ? $4 : $2 );
4888 # Go on to the end, and then stop.
4889 $end = $max if $end > $max;
4891 # Determine start line.
4893 $i = $line if $i eq '.';
4897 # If we're running under a slave editor, force it to show the lines.
4898 if ($slave_editor) {
4899 print $OUT "\032\032$filename:$i:0\n";
4903 # We're doing it ourselves. We want to show the line and special
4905 # - the current line in execution
4906 # - whether a line is breakable or not
4907 # - whether a line has a break or not
4908 # - whether a line has an action or not
4910 for ( ; $i <= $end ; $i++ ) {
4912 # Check for breakpoints and actions.
4913 my ( $stop, $action );
4914 ( $stop, $action ) = split( /\0/, $dbline{$i} )
4917 # ==> if this is the current line in execution,
4918 # : if it's breakable.
4920 ( $i == $current_line and $filename eq $filename_ini )
4922 : ( $dbline[$i] + 0 ? ':' : ' ' );
4924 # Add break and action indicators.
4925 $arrow .= 'b' if $stop;
4926 $arrow .= 'a' if $action;
4929 print $OUT "$i$arrow\t", $dbline[$i];
4931 # Move on to the next line. Drop out on an interrupt.
4932 $i++, last if $signal;
4933 } ## end for (; $i <= $end ; $i++)
4935 # Line the prompt up; print a newline if the last line listed
4936 # didn't have a newline.
4937 print $OUT "\n" unless $dbline[ $i - 1 ] =~ /\n$/;
4938 } ## end else [ if ($slave_editor)
4940 # Save the point we last listed to in case another relative 'l'
4941 # command is desired. Don't let it run off the end.
4943 $start = $max if $start > $max;
4944 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/)
4947 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
4949 To list breakpoints, the command has to look determine where all of them are
4950 first. It starts a C<%had_breakpoints>, which tells us what all files have
4951 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
4952 magic source and breakpoint data structures) to the file, and then look
4953 through C<%dbline> for lines with breakpoints and/or actions, listing them
4954 out. We look through C<%postponed> not-yet-compiled subroutines that have
4955 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
4956 that have breakpoints.
4958 Watchpoints are simpler: we just list the entries in C<@to_watch>.
4965 # If no argument, list everything. Pre-5.8.0 version always lists
4967 my $arg = shift || 'abw';
4968 $arg = 'abw' unless $CommandSet eq '580'; # sigh...
4970 # See what is wanted.
4971 my $action_wanted = ( $arg =~ /a/ ) ? 1 : 0;
4972 my $break_wanted = ( $arg =~ /b/ ) ? 1 : 0;
4973 my $watch_wanted = ( $arg =~ /w/ ) ? 1 : 0;
4975 # Breaks and actions are found together, so we look in the same place
4977 if ( $break_wanted or $action_wanted ) {
4979 # Look in all the files with breakpoints...
4980 for my $file ( keys %had_breakpoints ) {
4982 # Temporary switch to this file.
4983 local *dbline = $main::{ '_<' . $file };
4985 # Set up to look through the whole file.
4987 my $was; # Flag: did we print something
4990 # For each line in the file ...
4991 for ( $i = 1 ; $i <= $max ; $i++ ) {
4993 # We've got something on this line.
4994 if ( defined $dbline{$i} ) {
4996 # Print the header if we haven't.
4997 print $OUT "$file:\n" unless $was++;
5000 print $OUT " $i:\t", $dbline[$i];
5002 # Pull out the condition and the action.
5003 ( $stop, $action ) = split( /\0/, $dbline{$i} );
5005 # Print the break if there is one and it's wanted.
5006 print $OUT " break if (", $stop, ")\n"
5010 # Print the action if there is one and it's wanted.
5011 print $OUT " action: ", $action, "\n"
5015 # Quit if the user hit interrupt.
5017 } ## end if (defined $dbline{$i...
5018 } ## end for ($i = 1 ; $i <= $max...
5019 } ## end for my $file (keys %had_breakpoints)
5020 } ## end if ($break_wanted or $action_wanted)
5022 # Look for breaks in not-yet-compiled subs:
5023 if ( %postponed and $break_wanted ) {
5024 print $OUT "Postponed breakpoints in subroutines:\n";
5026 for $subname ( keys %postponed ) {
5027 print $OUT " $subname\t$postponed{$subname}\n";
5030 } ## end if (%postponed and $break_wanted)
5032 # Find files that have not-yet-loaded breaks:
5033 my @have = map { # Combined keys
5034 keys %{ $postponed_file{$_} }
5035 } keys %postponed_file;
5037 # If there are any, list them.
5038 if ( @have and ( $break_wanted or $action_wanted ) ) {
5039 print $OUT "Postponed breakpoints in files:\n";
5040 my ( $file, $line );
5042 for $file ( keys %postponed_file ) {
5043 my $db = $postponed_file{$file};
5044 print $OUT " $file:\n";
5045 for $line ( sort { $a <=> $b } keys %$db ) {
5046 print $OUT " $line:\n";
5047 my ( $stop, $action ) = split( /\0/, $$db{$line} );
5048 print $OUT " break if (", $stop, ")\n"
5051 print $OUT " action: ", $action, "\n"
5055 } ## end for $line (sort { $a <=>...
5057 } ## end for $file (keys %postponed_file)
5058 } ## end if (@have and ($break_wanted...
5059 if ( %break_on_load and $break_wanted ) {
5060 print $OUT "Breakpoints on load:\n";
5062 for $file ( keys %break_on_load ) {
5063 print $OUT " $file\n";
5066 } ## end if (%break_on_load and...
5067 if ($watch_wanted) {
5069 print $OUT "Watch-expressions:\n" if @to_watch;
5070 for my $expr (@to_watch) {
5071 print $OUT " $expr\n";
5074 } ## end if ($trace & 2)
5075 } ## end if ($watch_wanted)
5078 =head3 C<cmd_M> - list modules (command)
5080 Just call C<list_modules>.
5088 =head3 C<cmd_o> - options (command)
5090 If this is just C<o> by itself, we list the current settings via
5091 C<dump_option>. If there's a nonblank value following it, we pass that on to
5092 C<parse_options> for processing.
5098 my $opt = shift || ''; # opt[=val]
5100 # Nonblank. Try to parse and process.
5101 if ( $opt =~ /^(\S.*)/ ) {
5105 # Blank. List the current option settings.
5113 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5115 Advises the user that the O command has been renamed.
5120 print $OUT "The old O command is now the o command.\n"; # hint
5121 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5122 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5125 =head3 C<cmd_v> - view window (command)
5127 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5128 move back a few lines to list the selected line in context. Uses C<cmd_l>
5129 to do the actual listing after figuring out the range of line to request.
5137 # Extract the line to list around. (Astute readers will have noted that
5138 # this pattern will match whether or not a numeric line is specified,
5139 # which means that we'll always enter this loop (though a non-numeric
5140 # argument results in no action at all)).
5141 if ( $line =~ /^(\d*)$/ ) {
5143 # Total number of lines to list (a windowful).
5144 $incr = $window - 1;
5146 # Set the start to the argument given (if there was one).
5149 # Back up by the context amount.
5152 # Put together a linespec that cmd_l will like.
5153 $line = $start . '-' . ( $start + $incr );
5156 &cmd_l( 'l', $line );
5157 } ## end if ($line =~ /^(\d*)$/)
5160 =head3 C<cmd_w> - add a watch expression (command)
5162 The 5.8 version of this command adds a watch expression if one is specified;
5163 it does nothing if entered with no operands.
5165 We extract the expression, save it, evaluate it in the user's context, and
5166 save the value. We'll re-evaluate it each time the debugger passes a line,
5167 and will stop (see the code at the top of the command loop) if the value
5168 of any of the expressions changes.
5175 # Null expression if no arguments.
5176 my $expr = shift || '';
5178 # If expression is not null ...
5179 if ( $expr =~ /^(\S.*)/ ) {
5182 push @to_watch, $expr;
5184 # Parameterize DB::eval and call it to get the expression's value
5185 # in the user's context. This version can handle expressions which
5186 # return a list value.
5188 my ($val) = join( ' ', &eval );
5189 $val = ( defined $val ) ? "'$val'" : 'undef';
5191 # Save the current value of the expression.
5192 push @old_watch, $val;
5194 # We are now watching expressions.
5196 } ## end if ($expr =~ /^(\S.*)/)
5198 # You have to give one to get one.
5200 print $OUT "Adding a watch-expression requires an expression\n"; # hint
5204 =head3 C<cmd_W> - delete watch expressions (command)
5206 This command accepts either a watch expression to be removed from the list
5207 of watch expressions, or C<*> to delete them all.
5209 If C<*> is specified, we simply empty the watch expression list and the
5210 watch expression value list. We also turn off the bit that says we've got
5213 If an expression (or partial expression) is specified, we pattern-match
5214 through the expressions and remove the ones that match. We also discard
5215 the corresponding values. If no watch expressions are left, we turn off
5216 the 'watching expressions' bit.
5222 my $expr = shift || '';
5225 if ( $expr eq '*' ) {
5230 print $OUT "Deleting all watch expressions ...\n";
5233 @to_watch = @old_watch = ();
5236 # Delete one of them.
5237 elsif ( $expr =~ /^(\S.*)/ ) {
5239 # Where we are in the list.
5242 # For each expression ...
5243 foreach (@to_watch) {
5244 my $val = $to_watch[$i_cnt];
5246 # Does this one match the command argument?
5247 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
5248 # Yes. Turn it off, and its value too.
5249 splice( @to_watch, $i_cnt, 1 );
5250 splice( @old_watch, $i_cnt, 1 );
5253 } ## end foreach (@to_watch)
5255 # We don't bother to turn watching off because
5256 # a) we don't want to stop calling watchfunction() it it exists
5257 # b) foreach over a null list doesn't do anything anyway
5259 } ## end elsif ($expr =~ /^(\S.*)/)
5261 # No command arguments entered.
5264 "Deleting a watch-expression requires an expression, or '*' for all\n"
5269 ### END of the API section
5271 =head1 SUPPORT ROUTINES
5273 These are general support routines that are used in a number of places
5274 throughout the debugger.
5278 Something to do with assertions
5283 unless ($ini_assertion) {
5284 print $OUT "Assertions not supported in this Perl interpreter\n";
5286 if ( $cmd =~ /^.\b\s*([+-]?)\s*(~?)\s*(\w+(\s*\|\s*\w+)*)\s*$/ ) {
5287 my ( $how, $neg, $flags ) = ( $1, $2, $3 );
5288 my $acu = parse_DollarCaretP_flags($flags);
5289 if ( defined $acu ) {
5290 $acu = ~$acu if $neg;
5291 if ( $how eq '+' ) { $^P |= $acu }
5292 elsif ( $how eq '-' ) { $^P &= ~$acu }
5296 # else { print $OUT "undefined acu\n" }
5298 my $expanded = expand_DollarCaretP_flags($^P);
5299 print $OUT "Internal Perl debugger flags:\n\$^P=$expanded\n";
5306 save() saves the user's versions of globals that would mess us up in C<@saved>,
5307 and installs the versions we like better.
5313 # Save eval failure, command failure, extended OS error, output field
5314 # separator, input record separator, output record separator and
5315 # the warning setting.
5316 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
5318 $, = ""; # output field separator is null string
5319 $/ = "\n"; # input record separator is newline
5320 $\ = ""; # output record separator is null string
5321 $^W = 0; # warnings are off
5324 =head2 C<print_lineinfo> - show where we are now
5326 print_lineinfo prints whatever it is that it is handed; it prints it to the
5327 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
5328 us to feed line information to a slave editor without messing up the
5333 sub print_lineinfo {
5335 # Make the terminal sensible if we're not the primary debugger.
5336 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
5340 } ## end sub print_lineinfo
5342 =head2 C<postponed_sub>
5344 Handles setting postponed breakpoints in subroutines once they're compiled.
5345 For breakpoints, we use C<DB::find_sub> to locate the source file and line
5346 range for the subroutine, then mark the file as having a breakpoint,
5347 temporarily switch the C<*dbline> glob over to the source file, and then
5348 search the given range of lines to find a breakable line. If we find one,
5349 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
5353 # The following takes its argument via $evalarg to preserve current @_
5357 # Get the subroutine name.
5358 my $subname = shift;
5360 # If this is a 'break +<n> if <condition>' ...
5361 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
5363 # If there's no offset, use '+0'.
5364 my $offset = $1 || 0;
5366 # find_sub's value is 'fullpath-filename:start-stop'. It's
5367 # possible that the filename might have colons in it too.
5368 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
5371 # We got the start line. Add the offset '+<n>' from
5372 # $postponed{subname}.
5375 # Switch to the file this sub is in, temporarily.
5376 local *dbline = $main::{ '_<' . $file };
5378 # No warnings, please.
5379 local $^W = 0; # != 0 is magical below
5381 # This file's got a breakpoint in it.
5382 $had_breakpoints{$file} |= 1;
5384 # Last line in file.
5387 # Search forward until we hit a breakable line or get to
5388 # the end of the file.
5389 ++$i until $dbline[$i] != 0 or $i >= $max;
5391 # Copy the breakpoint in and delete it from %postponed.
5392 $dbline{$i} = delete $postponed{$subname};
5395 # find_sub didn't find the sub.
5398 print $OUT "Subroutine $subname not found.\n";
5401 } ## end if ($postponed{$subname...
5402 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
5404 #print $OUT "In postponed_sub for `$subname'.\n";
5405 } ## end sub postponed_sub
5409 Called after each required file is compiled, but before it is executed;
5410 also called if the name of a just-compiled subroutine is a key of
5411 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
5412 etc.) into the just-compiled code.
5414 If this is a C<require>'d file, the incoming parameter is the glob
5415 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
5417 If it's a subroutine, the incoming parameter is the subroutine name.
5423 # If there's a break, process it.
5424 if ($ImmediateStop) {
5426 # Right, we've stopped. Turn it off.
5429 # Enter the command loop when DB::DB gets called.
5433 # If this is a subroutine, let postponed_sub() deal with it.
5434 return &postponed_sub unless ref \$_[0] eq 'GLOB';
5436 # Not a subroutine. Deal with the file.
5437 local *dbline = shift;
5438 my $filename = $dbline;
5439 $filename =~ s/^_<//;
5441 $signal = 1, print $OUT "'$filename' loaded...\n"
5442 if $break_on_load{$filename};
5443 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
5445 # Do we have any breakpoints to put in this file?
5446 return unless $postponed_file{$filename};
5448 # Yes. Mark this file as having breakpoints.
5449 $had_breakpoints{$filename} |= 1;
5451 # "Cannot be done: unsufficient magic" - we can't just put the
5452 # breakpoints saved in %postponed_file into %dbline by assigning
5453 # the whole hash; we have to do it one item at a time for the
5454 # breakpoints to be set properly.
5455 #%dbline = %{$postponed_file{$filename}};
5457 # Set the breakpoints, one at a time.
5460 for $key ( keys %{ $postponed_file{$filename} } ) {
5462 # Stash the saved breakpoint into the current file's magic line array.
5463 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
5466 # This file's been compiled; discard the stored breakpoints.
5467 delete $postponed_file{$filename};
5469 } ## end sub postponed
5473 C<dumpit> is the debugger's wrapper around dumpvar.pl.
5475 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
5476 a reference to a variable (the thing to be dumped) as its input.
5478 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
5479 the currently-selected filehandle, thank you very much). The current
5480 values of the package globals C<$single> and C<$trace> are backed up in
5481 lexicals, and they are turned off (this keeps the debugger from trying
5482 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
5483 preserve its current value and it is set to zero to prevent entry/exit
5484 messages from printing, and C<$doret> is localized as well and set to -2 to
5485 prevent return values from being shown.
5487 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
5488 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
5489 installed version in @INC, yours will be used instead. Possible security
5492 It then checks to see if the subroutine C<main::dumpValue> is now defined
5493 (it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
5494 localizes the globals necessary for things to be sane when C<main::dumpValue()>
5495 is called, and picks up the variable to be dumped from the parameter list.
5497 It checks the package global C<%options> to see if there's a C<dumpDepth>
5498 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
5499 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
5500 structure: -1 means dump everything.
5502 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
5505 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
5506 and we then return to the caller.
5512 # Save the current output filehandle and switch to the one
5513 # passed in as the first parameter.
5514 local ($savout) = select(shift);
5516 # Save current settings of $single and $trace, and then turn them off.
5517 my $osingle = $single;
5518 my $otrace = $trace;
5519 $single = $trace = 0;
5521 # XXX Okay, what do $frame and $doret do, again?
5525 # Load dumpvar.pl unless we've already got the sub we need from it.
5526 unless ( defined &main::dumpValue ) {
5530 # If the load succeeded (or we already had dumpvalue()), go ahead
5532 if ( defined &main::dumpValue ) {
5537 my $maxdepth = shift || $option{dumpDepth};
5538 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
5539 &main::dumpValue( $v, $maxdepth );
5540 } ## end if (defined &main::dumpValue)
5542 # Oops, couldn't load dumpvar.pl.
5545 print $OUT "dumpvar.pl not available.\n";
5548 # Reset $single and $trace to their old values.
5552 # Restore the old filehandle.
5556 =head2 C<print_trace>
5558 C<print_trace>'s job is to print a stack trace. It does this via the
5559 C<dump_trace> routine, which actually does all the ferreting-out of the
5560 stack trace data. C<print_trace> takes care of formatting it nicely and
5561 printing it to the proper filehandle.
5567 =item * The filehandle to print to.
5569 =item * How many frames to skip before starting trace.
5571 =item * How many frames to print.
5573 =item * A flag: if true, print a "short" trace without filenames, line numbers, or arguments
5577 The original comment below seems to be noting that the traceback may not be
5578 correct if this routine is called in a tied method.
5582 # Tied method do not create a context, so may get wrong message:
5588 # If this is going to a slave editor, but we're not the primary
5589 # debugger, reset it first.
5591 if $fh eq $LINEINFO # slave editor
5592 and $LINEINFO eq $OUT # normal output
5593 and $term_pid != $$; # not the primary
5595 # Collect the actual trace information to be formatted.
5596 # This is an array of hashes of subroutine call info.
5597 my @sub = dump_trace( $_[0] + 1, $_[1] );
5599 # Grab the "short report" flag from @_.
5600 my $short = $_[2]; # Print short report, next one for sub name
5602 # Run through the traceback info, format it, and print it.
5604 for ( $i = 0 ; $i <= $#sub ; $i++ ) {
5606 # Drop out if the user has lost interest and hit control-C.
5609 # Set the separator so arrys print nice.
5612 # Grab and stringify the arguments if they are there.
5614 defined $sub[$i]{args}
5615 ? "(@{ $sub[$i]{args} })"
5618 # Shorten them up if $maxtrace says they're too long.
5619 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
5620 if length $args > $maxtrace;
5622 # Get the file name.
5623 my $file = $sub[$i]{file};
5625 # Put in a filename header if short is off.
5626 $file = $file eq '-e' ? $file : "file `$file'" unless $short;
5628 # Get the actual sub's name, and shorten to $maxtrace's requirement.
5630 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
5632 # Short report uses trimmed file and sub names.
5634 my $sub = @_ >= 4 ? $_[3] : $s;
5635 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
5636 } ## end if ($short)
5638 # Non-short report includes full names.
5640 print $fh "$sub[$i]{context} = $s$args"
5641 . " called from $file"
5642 . " line $sub[$i]{line}\n";
5644 } ## end for ($i = 0 ; $i <= $#sub...
5645 } ## end sub print_trace
5647 =head2 dump_trace(skip[,count])
5649 Actually collect the traceback information available via C<caller()>. It does
5650 some filtering and cleanup of the data, but mostly it just collects it to
5651 make C<print_trace()>'s job easier.
5653 C<skip> defines the number of stack frames to be skipped, working backwards
5654 from the most current. C<count> determines the total number of frames to
5655 be returned; all of them (well, the first 10^9) are returned if C<count>
5658 This routine returns a list of hashes, from most-recent to least-recent
5659 stack frame. Each has the following keys and values:
5663 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
5665 =item * C<sub> - subroutine name, or C<eval> information
5667 =item * C<args> - undef, or a reference to an array of arguments
5669 =item * C<file> - the file in which this item was defined (if any)
5671 =item * C<line> - the line on which it was defined
5679 # How many levels to skip.
5682 # How many levels to show. (1e9 is a cheap way of saying "all of them";
5683 # it's unlikely that we'll have more than a billion stack frames. If you
5684 # do, you've got an awfully big machine...)
5685 my $count = shift || 1e9;
5687 # We increment skip because caller(1) is the first level *back* from
5688 # the current one. Add $skip to the count of frames so we have a
5689 # simple stop criterion, counting from $skip to $count+$skip.
5693 # These variables are used to capture output from caller();
5694 my ( $p, $file, $line, $sub, $h, $context );
5696 my ( $e, $r, @a, @sub, $args );
5698 # XXX Okay... why'd we do that?
5699 my $nothard = not $frame & 8;
5702 # Do not want to trace this.
5703 my $otrace = $trace;
5706 # Start out at the skip count.
5707 # If we haven't reached the number of frames requested, and caller() is
5708 # still returning something, stay in the loop. (If we pass the requested
5709 # number of stack frames, or we run out - caller() returns nothing - we
5711 # Up the stack frame index to go back one more level each time.
5715 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
5720 # Go through the arguments and save them for later.
5724 if ( not defined $arg ) { # undefined parameter
5728 elsif ( $nothard and tied $arg ) { # tied parameter
5731 elsif ( $nothard and $type = ref $arg ) { # reference
5732 push @a, "ref($type)";
5734 else { # can be stringified
5736 "$arg"; # Safe to stringify now - should not call f().
5738 # Backslash any single-quotes or backslashes.
5741 # Single-quote it unless it's a number or a colon-separated
5744 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
5746 # Turn high-bit characters into meta-whatever.
5747 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
5749 # Turn control characters into ^-whatever.
5750 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
5753 } ## end else [ if (not defined $arg)
5754 } ## end for $arg (@args)
5756 # If context is true, this is array (@)context.
5757 # If context is false, this is scalar ($) context.
5758 # If neither, context isn't defined. (This is apparently a 'can't
5760 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
5762 # if the sub has args ($h true), make an anonymous array of the
5764 $args = $h ? [@a] : undef;
5766 # remove trailing newline-whitespace-semicolon-end of line sequence
5767 # from the eval text, if any.
5768 $e =~ s/\n\s*\;\s*\Z// if $e;
5770 # Escape backslashed single-quotes again if necessary.
5771 $e =~ s/([\\\'])/\\$1/g if $e;
5773 # if the require flag is true, the eval text is from a require.
5775 $sub = "require '$e'";
5778 # if it's false, the eval text is really from an eval.
5779 elsif ( defined $r ) {
5783 # If the sub is '(eval)', this is a block eval, meaning we don't
5784 # know what the eval'ed text actually was.
5785 elsif ( $sub eq '(eval)' ) {
5786 $sub = "eval {...}";
5789 # Stick the collected information into @sub as an anonymous hash.
5793 context => $context,
5801 # Stop processing frames if the user hit control-C.
5803 } ## end for ($i = $skip ; $i < ...
5805 # Restore the trace value again.
5808 } ## end sub dump_trace
5812 C<action()> takes input provided as the argument to an add-action command,
5813 either pre- or post-, and makes sure it's a complete command. It doesn't do
5814 any fancy parsing; it just keeps reading input until it gets a string
5815 without a trailing backslash.
5822 while ( $action =~ s/\\$// ) {
5824 # We have a backslash on the end. Read more.
5826 } ## end while ($action =~ s/\\$//)
5828 # Return the assembled action.
5834 This routine mostly just packages up a regular expression to be used
5835 to check that the thing it's being matched against has properly-matched
5838 Of note is the definition of the $balanced_brace_re global via ||=, which
5839 speeds things up by only creating the qr//'ed expression once; if it's
5840 already defined, we don't try to define it again. A speed hack.
5846 # I hate using globals!
5847 $balanced_brace_re ||= qr{
5850 (?> [^{}] + ) # Non-parens without backtracking
5852 (??{ $balanced_brace_re }) # Group with matching parens
5856 return $_[0] !~ m/$balanced_brace_re/;
5857 } ## end sub unbalanced
5861 C<gets()> is a primitive (very primitive) routine to read continuations.
5862 It was devised for reading continuations for actions.
5863 it just reads more input with X<C<readline()>> and returns it.
5868 &readline("cont: ");
5871 =head2 C<DB::system()> - handle calls to<system()> without messing up the debugger
5873 The C<system()> function assumes that it can just go ahead and use STDIN and
5874 STDOUT, but under the debugger, we want it to use the debugger's input and
5877 C<DB::system()> socks away the program's STDIN and STDOUT, and then substitutes
5878 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
5879 and then puts everything back again.
5885 # We save, change, then restore STDIN and STDOUT to avoid fork() since
5886 # some non-Unix systems can do system() but have problems with fork().
5887 open( SAVEIN, "<&STDIN" ) || &warn("Can't save STDIN");
5888 open( SAVEOUT, ">&STDOUT" ) || &warn("Can't save STDOUT");
5889 open( STDIN, "<&IN" ) || &warn("Can't redirect STDIN");
5890 open( STDOUT, ">&OUT" ) || &warn("Can't redirect STDOUT");
5892 # XXX: using csh or tcsh destroys sigint retvals!
5894 open( STDIN, "<&SAVEIN" ) || &warn("Can't restore STDIN");
5895 open( STDOUT, ">&SAVEOUT" ) || &warn("Can't restore STDOUT");
5899 # most of the $? crud was coping with broken cshisms
5901 &warn( "(Command exited ", ( $? >> 8 ), ")\n" );
5905 "(Command died of SIG#",
5907 ( ( $? & 128 ) ? " -- core dumped" : "" ),
5916 =head1 TTY MANAGEMENT
5918 The subs here do some of the terminal management for multiple debuggers.
5922 Top-level function called when we want to set up a new terminal for use
5925 If the C<noTTY> debugger option was set, we'll either use the terminal
5926 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
5927 to find one. If we're a forked debugger, we call C<resetterm> to try to
5928 get a whole new terminal if we can.
5930 In either case, we set up the terminal next. If the C<ReadLine> option was
5931 true, we'll get a C<Term::ReadLine> object for the current terminal and save
5932 the appropriate attributes. We then
5938 # Load Term::Readline, but quietly; don't debug it and don't trace it.
5941 eval { require Term::ReadLine } or die $@;
5943 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
5946 my ( $i, $o ) = split $tty, /,/;
5947 $o = $i unless defined $o;
5948 open( IN, "<$i" ) or die "Cannot open TTY `$i' for read: $!";
5949 open( OUT, ">$o" ) or die "Cannot open TTY `$o' for write: $!";
5952 my $sel = select($OUT);
5957 # We don't have a TTY - try to find one via Term::Rendezvous.
5959 eval "require Term::Rendezvous;" or die;
5961 # See if we have anything to pass to Term::Rendezvous.
5962 # Use /tmp/perldbtty$$ if not.
5963 my $rv = $ENV{PERLDB_NOTTY} || "/tmp/perldbtty$$";
5965 # Rendezvous and get the filehandles.
5966 my $term_rv = new Term::Rendezvous $rv;
5968 $OUT = $term_rv->OUT;
5969 } ## end else [ if ($tty)
5970 } ## end if ($notty)
5972 # We're a daughter debugger. Try to fork off another TTY.
5973 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
5977 # If we shouldn't use Term::ReadLine, don't.
5979 $term = new Term::ReadLine::Stub 'perldb', $IN, $OUT;
5982 # We're using Term::ReadLine. Get all the attributes for this terminal.
5984 $term = new Term::ReadLine 'perldb', $IN, $OUT;
5986 $rl_attribs = $term->Attribs;
5987 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
5988 if defined $rl_attribs->{basic_word_break_characters}
5989 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
5990 $rl_attribs->{special_prefixes} = '$@&%';
5991 $rl_attribs->{completer_word_break_characters} .= '$@&%';
5992 $rl_attribs->{completion_function} = \&db_complete;
5993 } ## end else [ if (!$rl)
5995 # Set up the LINEINFO filehandle.
5996 $LINEINFO = $OUT unless defined $LINEINFO;
5997 $lineinfo = $console unless defined $lineinfo;
6001 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6002 $term->SetHistory(@hist);
6005 # XXX Ornaments are turned on unconditionally, which is not
6006 # always a good thing.
6007 ornaments($ornaments) if defined $ornaments;
6009 } ## end sub setterm
6011 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6013 When the process being debugged forks, or the process invokes a command
6014 via C<system()> which starts a new debugger, we need to be able to get a new
6015 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6016 fight over the terminal, and you can never quite be sure who's going to get the
6017 input you're typing.
6019 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6020 is tasked with doing all the necessary operating system mojo to get a new
6021 TTY (and probably another window) and to direct the new debugger to read and
6024 The debugger provides C<get_fork_TTY> functions which work for X Windows and
6025 OS/2. Other systems are not supported. You are encouraged to write
6026 C<get_fork_TTY> functions which work for I<your> platform and contribute them.
6028 =head3 C<xterm_get_fork_TTY>
6030 This function provides the C<get_fork_TTY> function for X windows. If a
6031 program running under the debugger forks, a new <xterm> window is opened and
6032 the subsidiary debugger is directed there.
6034 The C<open()> call is of particular note here. We have the new C<xterm>
6035 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6036 command (which prints the device name of the TTY we'll want to use for input
6037 and output to STDOUT, then C<sleep> for a very long time, routing this output
6038 to file number 3. This way we can simply read from the <XT> filehandle (which
6039 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6041 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6046 sub xterm_get_fork_TTY {
6047 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6049 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6052 # Get the output from 'tty' and clean it up a little.
6056 $pidprompt = ''; # Shown anyway in titlebar
6058 # There's our new TTY.
6060 } ## end sub xterm_get_fork_TTY
6062 =head3 C<os2_get_fork_TTY>
6064 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6068 # This example function resets $IN, $OUT itself
6069 sub os2_get_fork_TTY {
6070 local $^F = 40; # XXXX Fixme!
6072 my ( $in1, $out1, $in2, $out2 );
6074 # Having -d in PERL5OPT would lead to a disaster...
6075 local $ENV{PERL5OPT} = $ENV{PERL5OPT} if $ENV{PERL5OPT};
6076 $ENV{PERL5OPT} =~ s/(?:^|(?<=\s))-d\b// if $ENV{PERL5OPT};
6077 $ENV{PERL5OPT} =~ s/(?:^|(?<=\s))-d\B/-/ if $ENV{PERL5OPT};
6078 print $OUT "Making kid PERL5OPT->`$ENV{PERL5OPT}'.\n" if $ENV{PERL5OPT};
6079 local $ENV{PERL5LIB} = $ENV{PERL5LIB} ? $ENV{PERL5LIB} : $ENV{PERLLIB};
6080 $ENV{PERL5LIB} = '' unless defined $ENV{PERL5LIB};
6081 $ENV{PERL5LIB} = join ';', @ini_INC, split /;/, $ENV{PERL5LIB};
6082 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6087 and pipe $in2, $out2
6089 # system P_SESSION will fail if there is another process
6090 # in the same session with a "dependent" asynchronous child session.
6092 $rl, fileno $in1, fileno $out2, "Daughter Perl debugger $pids $name"
6095 ( $kpid = CORE::system 4, $^X, '-we',
6096 <<'ES', @args ) >= 0 # P_SESSION
6097 END {sleep 5 unless $loaded}
6098 BEGIN {open STDIN, '</dev/con' or warn "reopen stdin: $!"}
6101 my ($rl, $in) = (shift, shift); # Read from $in and pass through
6103 system P_NOWAIT, $^X, '-we', <<EOS or die "Cannot start a grandkid";
6104 open IN, '<&=$in' or die "open <&=$in: \$!";
6105 \$| = 1; print while sysread IN, \$_, 1<<16;
6109 open OUT, ">&=$out" or die "Cannot open &=$out for writing: $!";
6111 require Term::ReadKey if $rl;
6112 Term::ReadKey::ReadMode(4) if $rl; # Nodelay on kbd. Pipe is automatically nodelay...
6113 print while sysread STDIN, $_, 1<<($rl ? 16 : 0);
6115 or warn "system P_SESSION: $!, $^E" and 0
6121 $pidprompt = ''; # Shown anyway in titlebar
6122 reset_IN_OUT( $in2, $out1 );
6124 return ''; # Indicate that reset_IN_OUT is called
6125 } ## end if (pipe $in1, $out1 and...
6127 } ## end sub os2_get_fork_TTY
6129 =head2 C<create_IN_OUT($flags)>
6131 Create a new pair of filehandles, pointing to a new TTY. If impossible,
6132 try to diagnose why.
6138 =item * 1 - Don't know how to create a new TTY.
6140 =item * 2 - Debugger has forked, but we can't get a new TTY.
6142 =item * 4 - standard debugger startup is happening.
6148 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
6150 # If we know how to get a new TTY, do it! $in will have
6151 # the TTY name if get_fork_TTY works.
6152 my $in = &get_fork_TTY if defined &get_fork_TTY;
6154 # It used to be that
6155 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
6157 if ( not defined $in ) {
6160 # We don't know how.
6161 print_help(<<EOP) if $why == 1;
6162 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
6166 print_help(<<EOP) if $why == 2;
6167 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
6168 This may be an asynchronous session, so the parent debugger may be active.
6171 # Note that both debuggers are fighting over the same input.
6172 print_help(<<EOP) if $why != 4;
6173 Since two debuggers fight for the same TTY, input is severely entangled.
6177 I know how to switch the output to a different window in xterms
6178 and OS/2 consoles only. For a manual switch, put the name of the created I<TTY>
6179 in B<\$DB::fork_TTY>, or define a function B<DB::get_fork_TTY()> returning this.
6181 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
6182 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
6185 } ## end if (not defined $in)
6186 elsif ( $in ne '' ) {
6190 $console = ''; # Indicate no need to open-from-the-console
6193 } ## end sub create_IN_OUT
6197 Handles rejiggering the prompt when we've forked off a new debugger.
6199 If the new debugger happened because of a C<system()> that invoked a
6200 program under the debugger, the arrow between the old pid and the new
6201 in the prompt has I<two> dashes instead of one.
6203 We take the current list of pids and add this one to the end. If there
6204 isn't any list yet, we make one up out of the initial pid associated with
6205 the terminal and our new pid, sticking an arrow (either one-dashed or
6206 two dashed) in between them.
6208 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
6209 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
6214 sub resetterm { # We forked, so we need a different TTY
6216 # Needs to be passed to create_IN_OUT() as well.
6219 # resetterm(2): got in here because of a system() starting a debugger.
6220 # resetterm(1): just forked.
6221 my $systemed = $in > 1 ? '-' : '';
6223 # If there's already a list of pids, add this to the end.
6225 $pids =~ s/\]/$systemed->$$]/;
6228 # No pid list. Time to make one.
6230 $pids = "[$term_pid->$$]";
6233 # The prompt we're going to be using for this debugger.
6236 # We now 0wnz this terminal.
6239 # Just return if we're not supposed to try to create a new TTY.
6240 return unless $CreateTTY & $in;
6242 # Try to create a new IN/OUT pair.
6244 } ## end sub resetterm
6248 First, we handle stuff in the typeahead buffer. If there is any, we shift off
6249 the next line, print a message saying we got it, add it to the terminal
6250 history (if possible), and return it.
6252 If there's nothing in the typeahead buffer, check the command filehandle stack.
6253 If there are any filehandles there, read from the last one, and return the line
6254 if we got one. If not, we pop the filehandle off and close it, and try the
6255 next one up the stack.
6257 If we've emptied the filehandle stack, we check to see if we've got a socket
6258 open, and we read that and return it if we do. If we don't, we just call the
6259 core C<readline()> and return its value.
6265 # Localize to prevent it from being smashed in the program being debugged.
6268 # Pull a line out of the typeahead if there's stuff there.
6271 # How many lines left.
6272 my $left = @typeahead;
6274 # Get the next line.
6275 my $got = shift @typeahead;
6277 # Print a message saying we got input from the typeahead.
6279 print $OUT "auto(-$left)", shift, $got, "\n";
6281 # Add it to the terminal history (if possible).
6282 $term->AddHistory($got)
6284 and defined $term->Features->{addHistory};
6286 } ## end if (@typeahead)
6288 # We really need to read some input. Turn off entry/exit trace and
6289 # return value printing.
6293 # If there are stacked filehandles to read from ...
6296 # Read from the last one in the stack.
6297 my $line = CORE::readline( $cmdfhs[-1] );
6299 # If we got a line ...
6301 ? ( print $OUT ">> $line" and return $line ) # Echo and return
6302 : close pop @cmdfhs; # Pop and close
6303 } ## end while (@cmdfhs)
6305 # Nothing on the filehandle stack. Socket?
6306 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
6308 # Send anyting we have to send.
6309 $OUT->write( join( '', @_ ) );
6311 # Receive anything there is to receive.
6313 $IN->recv( $stuff, 2048 ); # XXX "what's wrong with sysread?"
6314 # XXX Don't know. You tell me.
6318 } ## end if (ref $OUT and UNIVERSAL::isa...
6320 # No socket. Just read from the terminal.
6322 $term->readline(@_);
6324 } ## end sub readline
6326 =head1 OPTIONS SUPPORT ROUTINES
6328 These routines handle listing and setting option values.
6330 =head2 C<dump_option> - list the current value of an option setting
6332 This routine uses C<option_val> to look up the value for an option.
6333 It cleans up escaped single-quotes and then displays the option and
6339 my ( $opt, $val ) = @_;
6340 $val = option_val( $opt, 'N/A' );
6341 $val =~ s/([\\\'])/\\$1/g;
6342 printf $OUT "%20s = '%s'\n", $opt, $val;
6343 } ## end sub dump_option
6345 sub options2remember {
6346 foreach my $k (@RememberOnROptions) {
6347 $option{$k} = option_val( $k, 'N/A' );
6352 =head2 C<option_val> - find the current value of an option
6354 This can't just be a simple hash lookup because of the indirect way that
6355 the option values are stored. Some are retrieved by calling a subroutine,
6356 some are just variables.
6358 You must supply a default value to be used in case the option isn't set.
6363 my ( $opt, $default ) = @_;
6366 # Does this option exist, and is it a variable?
6367 # If so, retrieve the value via the value in %optionVars.
6368 if ( defined $optionVars{$opt}
6369 and defined ${ $optionVars{$opt} } )
6371 $val = ${ $optionVars{$opt} };
6374 # Does this option exist, and it's a subroutine?
6375 # If so, call the subroutine via the ref in %optionAction
6376 # and capture the value.
6377 elsif ( defined $optionAction{$opt}
6378 and defined &{ $optionAction{$opt} } )
6380 $val = &{ $optionAction{$opt} }();
6383 # If there's an action or variable for the supplied option,
6384 # but no value was set, use the default.
6385 elsif (defined $optionAction{$opt} and not defined $option{$opt}
6386 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
6391 # Otherwise, do the simple hash lookup.
6393 $val = $option{$opt};
6396 # If the value isn't defined, use the default.
6397 # Then return whatever the value is.
6398 $val = $default unless defined $val;
6400 } ## end sub option_val
6402 =head2 C<parse_options>
6404 Handles the parsing and execution of option setting/displaying commands.
6406 An option entered by itself is assumed to be 'set me to 1' (the default value)
6407 if the option is a boolean one. If not, the user is prompted to enter a valid
6408 value or to query the current value (via 'option? ').
6410 If 'option=value' is entered, we try to extract a quoted string from the
6411 value (if it is quoted). If it's not, we just use the whole value as-is.
6413 We load any modules required to service this option, and then we set it: if
6414 it just gets stuck in a variable, we do that; if there's a subroutine to
6415 handle setting the option, we call that.
6417 Finally, if we're running in interactive mode, we display the effect of the
6418 user's command back to the terminal, skipping this if we're setting things
6419 during initialization.
6427 # These options need a value. Don't allow them to be clobbered by accident.
6428 my %opt_needs_val = map { ( $_ => 1 ) } qw{
6429 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
6430 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
6436 # Clean off excess leading whitespace.
6439 # Options are always all word characters, followed by a non-word
6441 s/^(\w+)(\W?)// or print( $OUT "Invalid option `$_'\n" ), last;
6442 my ( $opt, $sep ) = ( $1, $2 );
6444 # Make sure that such an option exists.
6445 my $matches = grep( /^\Q$opt/ && ( $option = $_ ), @options )
6446 || grep( /^\Q$opt/i && ( $option = $_ ), @options );
6448 print( $OUT "Unknown option `$opt'\n" ), next unless $matches;
6449 print( $OUT "Ambiguous option `$opt'\n" ), next if $matches > 1;
6452 # '?' as separator means query, but must have whitespace after it.
6453 if ( "?" eq $sep ) {
6454 print( $OUT "Option query `$opt?' followed by non-space `$_'\n" ),
6458 #&dump_option($opt);
6459 } ## end if ("?" eq $sep)
6461 # Separator is whitespace (or just a carriage return).
6462 # They're going for a default, which we assume is 1.
6463 elsif ( $sep !~ /\S/ ) {
6465 $val = "1"; # this is an evil default; make 'em set it!
6468 # Separator is =. Trying to set a value.
6469 elsif ( $sep eq "=" ) {
6471 # If quoted, extract a quoted string.
6472 if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
6474 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
6477 # Not quoted. Use the whole thing. Warn about 'option='.
6481 print OUT qq(Option better cleared using $opt=""\n)
6483 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
6485 } ## end elsif ($sep eq "=")
6487 # "Quoted" with [], <>, or {}.
6488 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
6490 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
6491 s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
6492 or print( $OUT "Unclosed option value `$opt$sep$_'\n" ), last;
6493 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
6494 } ## end else [ if ("?" eq $sep)
6496 # Exclude non-booleans from getting set to 1 by default.
6497 if ( $opt_needs_val{$option} && $val_defaulted ) {
6498 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
6500 "Option `$opt' is non-boolean. Use `$cmd $option=VAL' to set, `$cmd $option?' to query\n";
6502 } ## end if ($opt_needs_val{$option...
6504 # Save the option value.
6505 $option{$option} = $val if defined $val;
6507 # Load any module that this option requires.
6511 require '$optionRequire{$option}';
6513 } || die # XXX: shouldn't happen
6514 if defined $optionRequire{$option}
6518 # Stick it in the proper variable if it goes in a variable.
6519 ${ $optionVars{$option} } = $val
6520 if defined $optionVars{$option}
6523 # Call the appropriate sub if it gets set via sub.
6524 &{ $optionAction{$option} }($val)
6525 if defined $optionAction{$option}
6526 && defined &{ $optionAction{$option} }
6529 # Not initialization - echo the value we set it to.
6530 dump_option($option) unless $OUT eq \*STDERR;
6531 } ## end while (length)
6532 } ## end sub parse_options
6534 =head1 RESTART SUPPORT
6536 These routines are used to store (and restore) lists of items in environment
6537 variables during a restart.
6541 Set_list packages up items to be stored in a set of environment variables
6542 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
6543 the values). Values outside the standard ASCII charset are stored by encoding
6544 then as hexadecimal values.
6549 my ( $stem, @list ) = @_;
6552 # VAR_n: how many we have. Scalar assignment gets the number of items.
6553 $ENV{"${stem}_n"} = @list;
6555 # Grab each item in the list, escape the backslashes, encode the non-ASCII
6556 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
6557 for $i ( 0 .. $#list ) {
6559 $val =~ s/\\/\\\\/g;
6560 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
6561 $ENV{"${stem}_$i"} = $val;
6562 } ## end for $i (0 .. $#list)
6563 } ## end sub set_list
6567 Reverse the set_list operation: grab VAR_n to see how many we should be getting
6568 back, and then pull VAR_0, VAR_1. etc. back out.
6575 my $n = delete $ENV{"${stem}_n"};
6577 for $i ( 0 .. $n - 1 ) {
6578 $val = delete $ENV{"${stem}_$i"};
6579 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
6583 } ## end sub get_list
6585 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
6589 The C<catch()> subroutine is the essence of fast and low-impact. We simply
6590 set an already-existing global scalar variable to a constant value. This
6591 avoids allocating any memory possibly in the middle of something that will
6592 get all confused if we do.
6598 return; # Put nothing on the stack - malloc/free land!
6603 C<warn> emits a warning, by joining together its arguments and printing
6604 them, with couple of fillips.
6606 If the composited message I<doesn't> end with a newline, we automatically
6607 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
6608 to be set to the filehandle to be used to output warnings; it makes no
6609 assumptions about what filehandles are available.
6614 my ($msg) = join( "", @_ );
6615 $msg .= ": $!\n" unless $msg =~ /\n$/;
6620 =head1 INITIALIZATION TTY SUPPORT
6622 =head2 C<reset_IN_OUT>
6624 This routine handles restoring the debugger's input and output filehandles
6625 after we've tried and failed to move them elsewhere. In addition, it assigns
6626 the debugger's output filehandle to $LINEINFO if it was already open there.
6631 my $switch_li = $LINEINFO eq $OUT;
6633 # If there's a term and it's able to get a new tty, try to get one.
6634 if ( $term and $term->Features->{newTTY} ) {
6635 ( $IN, $OUT ) = ( shift, shift );
6636 $term->newTTY( $IN, $OUT );
6639 # This term can't get a new tty now. Better luck later.
6641 &warn("Too late to set IN/OUT filehandles, enabled on next `R'!\n");
6644 # Set the filehndles up as they were.
6646 ( $IN, $OUT ) = ( shift, shift );
6649 # Unbuffer the output filehandle.
6650 my $o = select $OUT;
6654 # Point LINEINFO to the same output filehandle if it was there before.
6655 $LINEINFO = $OUT if $switch_li;
6656 } ## end sub reset_IN_OUT
6658 =head1 OPTION SUPPORT ROUTINES
6660 The following routines are used to process some of the more complicated
6665 Sets the input and output filehandles to the specified files or pipes.
6666 If the terminal supports switching, we go ahead and do it. If not, and
6667 there's already a terminal in place, we save the information to take effect
6670 If there's no terminal yet (for instance, during debugger initialization),
6671 we go ahead and set C<$console> and C<$tty> to the file indicated.
6676 if ( @_ and $term and $term->Features->{newTTY} ) {
6678 # This terminal supports switching to a new TTY.
6679 # Can be a list of two files, or on string containing both names,
6681 # XXX Should this perhaps be an assignment from @_?
6682 my ( $in, $out ) = shift;
6685 # Split list apart if supplied.
6686 ( $in, $out ) = split /,/, $in, 2;
6690 # Use the same file for both input and output.
6694 # Open file onto the debugger's filehandles, if you can.
6695 open IN, $in or die "cannot open `$in' for read: $!";
6696 open OUT, ">$out" or die "cannot open `$out' for write: $!";
6698 # Swap to the new filehandles.
6699 reset_IN_OUT( \*IN, \*OUT );
6701 # Save the setting for later.
6703 } ## end if (@_ and $term and $term...
6705 # Terminal doesn't support new TTY, or doesn't support readline.
6706 # Can't do it now, try restarting.
6707 &warn("Too late to set TTY, enabled on next `R'!\n") if $term and @_;
6709 # Useful if done through PERLDB_OPTS:
6710 $console = $tty = shift if @_;
6712 # Return whatever the TTY is.
6718 Sets the C<$notty> global, controlling whether or not the debugger tries to
6719 get a terminal to read from. If called after a terminal is already in place,
6720 we save the value to use it if we're restarted.
6726 &warn("Too late to set noTTY, enabled on next `R'!\n") if @_;
6728 $notty = shift if @_;
6734 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
6735 (essentially, no C<readline> processing on this "terminal"). Otherwise, we
6736 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
6737 the value in case a restart is done so we can change it then.
6743 &warn("Too late to set ReadLine, enabled on next `R'!\n") if @_;
6747 } ## end sub ReadLine
6749 =head2 C<RemotePort>
6751 Sets the port that the debugger will try to connect to when starting up.
6752 If the terminal's already been set up, we can't do it, but we remember the
6753 setting in case the user does a restart.
6759 &warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
6761 $remoteport = shift if @_;
6763 } ## end sub RemotePort
6767 Checks with the terminal to see if C<Tk> is running, and returns true or
6768 false. Returns false if the current terminal doesn't support C<readline>.
6773 if ( ${ $term->Features }{tkRunning} ) {
6774 return $term->tkRunning(@_);
6778 print $OUT "tkRunning not supported by current ReadLine package.\n";
6781 } ## end sub tkRunning
6785 Sets nonstop mode. If a terminal's already been set up, it's too late; the
6786 debugger remembers the setting in case you restart, though.
6792 &warn("Too late to set up NonStop mode, enabled on next `R'!\n")
6795 $runnonstop = shift if @_;
6797 } ## end sub NonStop
6801 &warn("Some flag changes could not take effect until next 'R'!\n")
6804 $^P = parse_DollarCaretP_flags(shift) if @_;
6805 expand_DollarCaretP_flags($^P);
6808 sub OnlyAssertions {
6810 &warn("Too late to set up OnlyAssertions mode, enabled on next 'R'!\n")
6814 unless ( defined $ini_assertion ) {
6816 &warn("Current Perl interpreter doesn't support assertions");
6821 unless ($ini_assertion) {
6822 print "Assertions will be active on next 'R'!\n";
6825 $^P &= ~$DollarCaretP_flags{PERLDBf_SUB};
6826 $^P |= $DollarCaretP_flags{PERLDBf_ASSERTION};
6829 $^P |= $DollarCaretP_flags{PERLDBf_SUB};
6832 !( $^P & $DollarCaretP_flags{PERLDBf_SUB} ) || 0;
6837 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
6845 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
6852 Sets the shell escape command, and generates a printable copy to be used
6859 # If we got an argument, meta-quote it, and add '\b' if it
6860 # ends in a word character.
6862 $sh = quotemeta shift;
6863 $sh .= "\\b" if $sh =~ /\w$/;
6866 # Generate the printable version for the help:
6867 $psh = $sh; # copy it
6868 $psh =~ s/\\b$//; # Take off trailing \b if any
6869 $psh =~ s/\\(.)/$1/g; # De-escape
6870 $psh; # return the printable version
6871 } ## end sub shellBang
6875 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
6876 was passed as the argument. (This means you can't override the terminal's
6882 if ( defined $term ) {
6884 # We don't want to show warning backtraces, but we do want die() ones.
6885 local ( $warnLevel, $dieLevel ) = ( 0, 1 );
6887 # No ornaments if the terminal doesn't support them.
6888 return '' unless $term->Features->{ornaments};
6889 eval { $term->ornaments(@_) } || '';
6892 # Use what was passed in if we can't determine it ourselves.
6896 } ## end sub ornaments
6898 =head2 C<recallCommand>
6900 Sets the recall command, and builds a printable version which will appear in
6907 # If there is input, metaquote it. Add '\b' if it ends with a word
6910 $rc = quotemeta shift;
6911 $rc .= "\\b" if $rc =~ /\w$/;
6914 # Build it into a printable version.
6915 $prc = $rc; # Copy it
6916 $prc =~ s/\\b$//; # Remove trailing \b
6917 $prc =~ s/\\(.)/$1/g; # Remove escapes
6918 $prc; # Return the printable version
6919 } ## end sub recallCommand
6921 =head2 C<LineInfo> - where the line number information goes
6923 Called with no arguments, returns the file or pipe that line info should go to.
6925 Called with an argument (a file or a pipe), it opens that onto the
6926 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
6927 file or pipe again to the caller.
6932 return $lineinfo unless @_;
6935 # If this is a valid "thing to be opened for output", tack a
6936 # '>' onto the front.
6937 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
6939 # If this is a pipe, the stream points to a slave editor.
6940 $slave_editor = ( $stream =~ /^\|/ );
6942 # Open it up and unbuffer it.
6943 open( LINEINFO, "$stream" ) || &warn("Cannot open `$stream' for write");
6944 $LINEINFO = \*LINEINFO;
6945 my $save = select($LINEINFO);
6949 # Hand the file or pipe back again.
6951 } ## end sub LineInfo
6953 =head1 COMMAND SUPPORT ROUTINES
6955 These subroutines provide functionality for various commands.
6957 =head2 C<list_modules>
6959 For the C<M> command: list modules loaded and their versions.
6960 Essentially just runs through the keys in %INC, picks up the
6961 $VERSION package globals from each package, gets the file name, and formats the
6962 information for output.
6966 sub list_modules { # versions
6970 # keys are the "as-loaded" name, values are the fully-qualified path
6971 # to the file itself.
6973 $file = $_; # get the module name
6974 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
6975 s,/,::,g; # change '/' to '::'
6976 s/^perl5db$/DB/; # Special case: debugger
6977 # moves to package DB
6978 s/^Term::ReadLine::readline$/readline/; # simplify readline
6980 # If the package has a $VERSION package global (as all good packages
6981 # should!) decode it and save as partial message.
6982 if ( defined ${ $_ . '::VERSION' } ) {
6983 $version{$file} = "${ $_ . '::VERSION' } from ";
6986 # Finish up the message with the file the package came from.
6987 $version{$file} .= $INC{$file};
6988 } ## end for (keys %INC)
6990 # Hey, dumpit() formats a hash nicely, so why not use it?
6991 dumpit( $OUT, \%version );
6992 } ## end sub list_modules
6996 Sets up the monster string used to format and print the help.
6998 =head3 HELP MESSAGE FORMAT
7000 The help message is a peculiar format unto itself; it mixes C<pod> 'ornaments'
7001 (BE<lt>E<gt>, IE<gt>E<lt>) with tabs to come up with a format that's fairly
7002 easy to parse and portable, but which still allows the help to be a little
7003 nicer than just plain text.
7005 Essentially, you define the command name (usually marked up with BE<gt>E<lt>
7006 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
7007 need to continue the descriptive text to another line, start that line with
7008 just tabs and then enter the marked-up text.
7010 If you are modifying the help text, I<be careful>. The help-string parser is
7011 not very sophisticated, and if you don't follow these rules it will mangle the
7012 help beyond hope until you fix the string.
7018 # XXX: make sure there are tabs between the command and explanation,
7019 # or print_help will screw up your formatting if you have
7020 # eeevil ornaments enabled. This is an insane mess.
7023 Help is currently only available for the new 5.8 command set.
7024 No help is available for the old command set.
7025 We assume you know what you're doing if you switch to it.
7028 B<s> [I<expr>] Single step [in I<expr>].
7029 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7030 <B<CR>> Repeat last B<n> or B<s> command.
7031 B<r> Return from current subroutine.
7032 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7033 at the specified position.
7034 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7035 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7036 B<l> I<line> List single I<line>.
7037 B<l> I<subname> List first window of lines from subroutine.
7038 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7039 B<l> List next window of lines.
7040 B<-> List previous window of lines.
7041 B<v> [I<line>] View window around I<line>.
7042 B<.> Return to the executed line.
7043 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7044 I<filename> may be either the full name of the file, or a regular
7045 expression matching the full file name:
7046 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7047 Evals (with saved bodies) are considered to be filenames:
7048 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7049 (in the order of execution).
7050 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7051 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7052 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
7053 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7054 B<t> Toggle trace mode.
7055 B<t> I<expr> Trace through execution of I<expr>.
7056 B<b> Sets breakpoint on current line)
7057 B<b> [I<line>] [I<condition>]
7058 Set breakpoint; I<line> defaults to the current execution line;
7059 I<condition> breaks if it evaluates to true, defaults to '1'.
7060 B<b> I<subname> [I<condition>]
7061 Set breakpoint at first line of subroutine.
7062 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7063 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7064 B<b> B<postpone> I<subname> [I<condition>]
7065 Set breakpoint at first line of subroutine after
7067 B<b> B<compile> I<subname>
7068 Stop after the subroutine is compiled.
7069 B<B> [I<line>] Delete the breakpoint for I<line>.
7070 B<B> I<*> Delete all breakpoints.
7071 B<a> [I<line>] I<command>
7072 Set an action to be done before the I<line> is executed;
7073 I<line> defaults to the current execution line.
7074 Sequence is: check for breakpoint/watchpoint, print line
7075 if necessary, do action, prompt user if necessary,
7078 B<A> [I<line>] Delete the action for I<line>.
7079 B<A> I<*> Delete all actions.
7080 B<w> I<expr> Add a global watch-expression.
7082 B<W> I<expr> Delete a global watch-expression.
7083 B<W> I<*> Delete all watch-expressions.
7084 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7085 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7086 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7087 B<x> I<expr> Evals expression in list context, dumps the result.
7088 B<m> I<expr> Evals expression in list context, prints methods callable
7089 on the first element of the result.
7090 B<m> I<class> Prints methods callable via the given class.
7091 B<M> Show versions of loaded modules.
7092 B<i> I<class> Prints nested parents of given class.
7093 B<e> Display current thread id.
7094 B<E> Display all thread ids the current one will be identified: <n>.
7095 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7096 B<P> Something to do with assertions...
7098 B<<> ? List Perl commands to run before each prompt.
7099 B<<> I<expr> Define Perl command to run before each prompt.
7100 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7101 B<< *> Delete the list of perl commands to run before each prompt.
7102 B<>> ? List Perl commands to run after each prompt.
7103 B<>> I<expr> Define Perl command to run after each prompt.
7104 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7105 B<>>B< *> Delete the list of Perl commands to run after each prompt.
7106 B<{> I<db_command> Define debugger command to run before each prompt.
7107 B<{> ? List debugger commands to run before each prompt.
7108 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7109 B<{ *> Delete the list of debugger commands to run before each prompt.
7110 B<$prc> I<number> Redo a previous command (default previous command).
7111 B<$prc> I<-number> Redo number'th-to-last command.
7112 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7113 See 'B<O> I<recallCommand>' too.
7114 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7119 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7121 See 'B<O> I<shellBang>' too.
7122 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7123 B<save> I<file> Save current debugger session (actual history) to I<file>.
7124 B<rerun> Rerun session to current position.
7125 B<rerun> I<n> Rerun session to numbered command.
7126 B<rerun> I<-n> Rerun session to number'th-to-last command.
7127 B<H> I<-number> Display last number commands (default all).
7128 B<H> I<*> Delete complete history.
7129 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7130 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7131 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7132 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7133 I<command> Execute as a perl statement in current package.
7134 B<R> Pure-man-restart of debugger, some of debugger state
7135 and command-line options may be lost.
7136 Currently the following settings are preserved:
7137 history, breakpoints and actions, debugger B<O>ptions
7138 and the following command-line options: I<-w>, I<-I>, I<-e>.
7140 B<o> [I<opt>] ... Set boolean option to true
7141 B<o> [I<opt>B<?>] Query options
7142 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7143 Set options. Use quotes in spaces in value.
7144 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7145 I<pager> program for output of \"|cmd\";
7146 I<tkRunning> run Tk while prompting (with ReadLine);
7147 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7148 I<inhibit_exit> Allows stepping off the end of the script.
7149 I<ImmediateStop> Debugger should stop as early as possible.
7150 I<RemotePort> Remote hostname:port for remote debugging
7151 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7152 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7153 I<compactDump>, I<veryCompact> change style of array and hash dump;
7154 I<globPrint> whether to print contents of globs;
7155 I<DumpDBFiles> dump arrays holding debugged files;
7156 I<DumpPackages> dump symbol tables of packages;
7157 I<DumpReused> dump contents of \"reused\" addresses;
7158 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7159 I<bareStringify> Do not print the overload-stringified value;
7160 Other options include:
7161 I<PrintRet> affects printing of return value after B<r> command,
7162 I<frame> affects printing messages on subroutine entry/exit.
7163 I<AutoTrace> affects printing messages on possible breaking points.
7164 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7165 I<ornaments> affects screen appearance of the command line.
7166 I<CreateTTY> bits control attempts to create a new TTY on events:
7167 1: on fork() 2: debugger is started inside debugger
7169 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7170 You can put additional initialization options I<TTY>, I<noTTY>,
7171 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7172 `B<R>' after you set them).
7174 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7175 B<h> Summary of debugger commands.
7176 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7177 B<h h> Long help for debugger commands
7178 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7179 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7180 Set B<\$DB::doccmd> to change viewer.
7182 Type `|h h' for a paged display if this was too hard to read.
7184 "; # Fix balance of vi % matching: }}}}
7186 # note: tabs in the following section are not-so-helpful
7187 $summary = <<"END_SUM";
7188 I<List/search source lines:> I<Control script execution:>
7189 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7190 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7191 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
7192 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7193 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7194 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
7195 I<Debugger controls:> B<L> List break/watch/actions
7196 B<o> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7197 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7198 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
7199 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7200 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
7201 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
7202 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
7203 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7204 B<q> or B<^D> Quit B<R> Attempt a restart
7205 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7206 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7207 B<p> I<expr> Print expression (uses script's current package).
7208 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7209 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7210 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
7211 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7212 B<e> Display thread id B<E> Display all thread ids.
7213 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7216 # ')}}; # Fix balance of vi % matching
7218 # and this is really numb...
7221 B<s> [I<expr>] Single step [in I<expr>].
7222 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7223 B<CR>> Repeat last B<n> or B<s> command.
7224 B<r> Return from current subroutine.
7225 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7226 at the specified position.
7227 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7228 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7229 B<l> I<line> List single I<line>.
7230 B<l> I<subname> List first window of lines from subroutine.
7231 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7232 B<l> List next window of lines.
7233 B<-> List previous window of lines.
7234 B<w> [I<line>] List window around I<line>.
7235 B<.> Return to the executed line.
7236 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7237 I<filename> may be either the full name of the file, or a regular
7238 expression matching the full file name:
7239 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7240 Evals (with saved bodies) are considered to be filenames:
7241 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7242 (in the order of execution).
7243 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7244 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7245 B<L> List all breakpoints and actions.
7246 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7247 B<t> Toggle trace mode.
7248 B<t> I<expr> Trace through execution of I<expr>.
7249 B<b> [I<line>] [I<condition>]
7250 Set breakpoint; I<line> defaults to the current execution line;
7251 I<condition> breaks if it evaluates to true, defaults to '1'.
7252 B<b> I<subname> [I<condition>]
7253 Set breakpoint at first line of subroutine.
7254 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7255 B<b> B<load> I<filename> Set breakpoint on `require'ing the given file.
7256 B<b> B<postpone> I<subname> [I<condition>]
7257 Set breakpoint at first line of subroutine after
7259 B<b> B<compile> I<subname>
7260 Stop after the subroutine is compiled.
7261 B<d> [I<line>] Delete the breakpoint for I<line>.
7262 B<D> Delete all breakpoints.
7263 B<a> [I<line>] I<command>
7264 Set an action to be done before the I<line> is executed;
7265 I<line> defaults to the current execution line.
7266 Sequence is: check for breakpoint/watchpoint, print line
7267 if necessary, do action, prompt user if necessary,
7269 B<a> [I<line>] Delete the action for I<line>.
7270 B<A> Delete all actions.
7271 B<W> I<expr> Add a global watch-expression.
7272 B<W> Delete all watch-expressions.
7273 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7274 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7275 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7276 B<x> I<expr> Evals expression in list context, dumps the result.
7277 B<m> I<expr> Evals expression in list context, prints methods callable
7278 on the first element of the result.
7279 B<m> I<class> Prints methods callable via the given class.
7281 B<<> ? List Perl commands to run before each prompt.
7282 B<<> I<expr> Define Perl command to run before each prompt.
7283 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7284 B<>> ? List Perl commands to run after each prompt.
7285 B<>> I<expr> Define Perl command to run after each prompt.
7286 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7287 B<{> I<db_command> Define debugger command to run before each prompt.
7288 B<{> ? List debugger commands to run before each prompt.
7289 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7290 B<$prc> I<number> Redo a previous command (default previous command).
7291 B<$prc> I<-number> Redo number'th-to-last command.
7292 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7293 See 'B<O> I<recallCommand>' too.
7294 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7299 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7301 See 'B<O> I<shellBang>' too.
7302 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7303 B<H> I<-number> Display last number commands (default all).
7304 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7305 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7306 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7307 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7308 I<command> Execute as a perl statement in current package.
7309 B<v> Show versions of loaded modules.
7310 B<R> Pure-man-restart of debugger, some of debugger state
7311 and command-line options may be lost.
7312 Currently the following settings are preserved:
7313 history, breakpoints and actions, debugger B<O>ptions
7314 and the following command-line options: I<-w>, I<-I>, I<-e>.
7316 B<O> [I<opt>] ... Set boolean option to true
7317 B<O> [I<opt>B<?>] Query options
7318 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7319 Set options. Use quotes in spaces in value.
7320 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7321 I<pager> program for output of \"|cmd\";
7322 I<tkRunning> run Tk while prompting (with ReadLine);
7323 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7324 I<inhibit_exit> Allows stepping off the end of the script.
7325 I<ImmediateStop> Debugger should stop as early as possible.
7326 I<RemotePort> Remote hostname:port for remote debugging
7327 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7328 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7329 I<compactDump>, I<veryCompact> change style of array and hash dump;
7330 I<globPrint> whether to print contents of globs;
7331 I<DumpDBFiles> dump arrays holding debugged files;
7332 I<DumpPackages> dump symbol tables of packages;
7333 I<DumpReused> dump contents of \"reused\" addresses;
7334 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7335 I<bareStringify> Do not print the overload-stringified value;
7336 Other options include:
7337 I<PrintRet> affects printing of return value after B<r> command,
7338 I<frame> affects printing messages on subroutine entry/exit.
7339 I<AutoTrace> affects printing messages on possible breaking points.
7340 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7341 I<ornaments> affects screen appearance of the command line.
7342 I<CreateTTY> bits control attempts to create a new TTY on events:
7343 1: on fork() 2: debugger is started inside debugger
7345 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7346 You can put additional initialization options I<TTY>, I<noTTY>,
7347 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7348 `B<R>' after you set them).
7350 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7351 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7352 B<h h> Summary of debugger commands.
7353 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7354 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7355 Set B<\$DB::doccmd> to change viewer.
7357 Type `|h' for a paged display if this was too hard to read.
7359 "; # Fix balance of vi % matching: }}}}
7361 # note: tabs in the following section are not-so-helpful
7362 $pre580_summary = <<"END_SUM";
7363 I<List/search source lines:> I<Control script execution:>
7364 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7365 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7366 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
7367 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7368 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7369 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
7370 I<Debugger controls:> B<L> List break/watch/actions
7371 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7372 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7373 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
7374 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7375 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
7376 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
7377 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7378 B<q> or B<^D> Quit B<R> Attempt a restart
7379 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7380 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7381 B<p> I<expr> Print expression (uses script's current package).
7382 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7383 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7384 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
7385 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7386 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7389 # ')}}; # Fix balance of vi % matching
7391 } ## end sub sethelp
7393 =head2 C<print_help()>
7395 Most of what C<print_help> does is just text formatting. It finds the
7396 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
7397 terminal control characters to simulate them (courtesy of
7398 <Term::ReadLine::TermCap>).
7405 # Restore proper alignment destroyed by eeevil I<> and B<>
7406 # ornaments: A pox on both their houses!
7408 # A help command will have everything up to and including
7409 # the first tab sequence padded into a field 16 (or if indented 20)
7410 # wide. If it's wider than that, an extra space will be added.
7412 ^ # only matters at start of line
7413 ( \040{4} | \t )* # some subcommands are indented
7414 ( < ? # so <CR> works
7415 [BI] < [^\t\n] + ) # find an eeevil ornament
7416 ( \t+ ) # original separation, discarded
7417 ( .* ) # this will now start (no earlier) than
7420 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
7421 my $clean = $command;
7422 $clean =~ s/[BI]<([^>]*)>/$1/g;
7424 # replace with this whole string:
7425 ($leadwhite ? " " x 4 : "")
7427 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
7432 s{ # handle bold ornaments
7433 B < ( [^>] + | > ) >
7435 $Term::ReadLine::TermCap::rl_term_set[2]
7437 . $Term::ReadLine::TermCap::rl_term_set[3]
7440 s{ # handle italic ornaments
7441 I < ( [^>] + | > ) >
7443 $Term::ReadLine::TermCap::rl_term_set[0]
7445 . $Term::ReadLine::TermCap::rl_term_set[1]
7450 } ## end sub print_help
7454 This routine does a lot of gyrations to be sure that the pager is C<less>.
7455 It checks for C<less> masquerading as C<more> and records the result in
7456 C<$ENV{LESS}> so we don't have to go through doing the stats again.
7462 # We already know if this is set.
7463 return if defined $ENV{LESS} && $ENV{LESS} =~ /r/;
7465 # Pager is less for sure.
7466 my $is_less = $pager =~ /\bless\b/;
7467 if ( $pager =~ /\bmore\b/ ) {
7469 # Nope, set to more. See what's out there.
7470 my @st_more = stat('/usr/bin/more');
7471 my @st_less = stat('/usr/bin/less');
7473 # is it really less, pretending to be more?
7476 && $st_more[0] == $st_less[0]
7477 && $st_more[1] == $st_less[1];
7478 } ## end if ($pager =~ /\bmore\b/)
7480 # changes environment!
7481 # 'r' added so we don't do (slow) stats again.
7482 $ENV{LESS} .= 'r' if $is_less;
7483 } ## end sub fix_less
7485 =head1 DIE AND WARN MANAGEMENT
7489 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
7490 to debug a debugger problem.
7492 It does its best to report the error that occurred, and then forces the
7493 program, debugger, and everything to die.
7499 # No entry/exit messages.
7502 # No return value prints.
7505 # set the abort signal handling to the default (just terminate).
7506 $SIG{'ABRT'} = 'DEFAULT';
7508 # If we enter the signal handler recursively, kill myself with an
7509 # abort signal (so we just terminate).
7510 kill 'ABRT', $$ if $panic++;
7512 # If we can show detailed info, do so.
7513 if ( defined &Carp::longmess ) {
7515 # Don't recursively enter the warn handler, since we're carping.
7516 local $SIG{__WARN__} = '';
7518 # Skip two levels before reporting traceback: we're skipping
7519 # mydie and confess.
7520 local $Carp::CarpLevel = 2; # mydie + confess
7522 # Tell us all about it.
7523 &warn( Carp::longmess("Signal @_") );
7526 # No Carp. Tell us about the signal as best we can.
7529 print $DB::OUT "Got signal @_\n";
7534 } ## end sub diesignal
7538 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
7539 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
7545 # No entry/exit trace.
7548 # No return value printing.
7551 # Turn off warn and die handling to prevent recursive entries to this
7553 local $SIG{__WARN__} = '';
7554 local $SIG{__DIE__} = '';
7556 # Load Carp if we can. If $^S is false (current thing being compiled isn't
7557 # done yet), we may not be able to do a require.
7558 eval { require Carp }
7559 if defined $^S; # If error/warning during compilation,
7560 # require may be broken.
7562 # Use the core warn() unless Carp loaded OK.
7564 "\nCannot print stack trace, load with -MCarp option to see stack" ),
7566 unless defined &Carp::longmess;
7568 # Save the current values of $single and $trace, and then turn them off.
7569 my ( $mysingle, $mytrace ) = ( $single, $trace );
7573 # We can call Carp::longmess without its being "debugged" (which we
7574 # don't want - we just want to use it!). Capture this for later.
7575 my $mess = Carp::longmess(@_);
7577 # Restore $single and $trace to their original values.
7578 ( $single, $trace ) = ( $mysingle, $mytrace );
7580 # Use the debugger's own special way of printing warnings to print
7581 # the stack trace message.
7587 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
7588 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
7589 single stepping and tracing during the call to C<Carp::longmess> to avoid
7590 debugging it - we just want to use it.
7592 If C<dieLevel> is zero, we let the program being debugged handle the
7593 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
7594 the debugger takes over all exception handling, printing a backtrace and
7595 displaying the exception via its C<dbwarn()> routine.
7602 local $SIG{__DIE__} = '';
7603 local $SIG{__WARN__} = '';
7607 if ( $dieLevel > 2 ) {
7608 local $SIG{__WARN__} = \&dbwarn;
7609 &warn(@_); # Yell no matter what
7612 if ( $dieLevel < 2 ) {
7613 die @_ if $^S; # in eval propagate
7616 # The code used to check $^S to see if compiliation of the current thing
7617 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
7618 eval { require Carp };
7621 "\nCannot print stack trace, load with -MCarp option to see stack" )
7622 unless defined &Carp::longmess;
7624 # We do not want to debug this chunk (automatic disabling works
7625 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
7626 # get the stack trace from Carp::longmess (if possible), restore $signal
7627 # and $trace, and then die with the stack trace.
7628 my ( $mysingle, $mytrace ) = ( $single, $trace );
7634 package Carp; # Do not include us in the list
7635 eval { $mess = Carp::longmess(@_); };
7637 ( $single, $trace ) = ( $mysingle, $mytrace );
7641 =head2 C<warnlevel()>
7643 Set the C<$DB::warnLevel> variable that stores the value of the
7644 C<warnLevel> option. Calling C<warnLevel()> with a positive value
7645 results in the debugger taking over all warning handlers. Setting
7646 C<warnLevel> to zero leaves any warning handlers set up by the program
7647 being debugged in place.
7653 $prevwarn = $SIG{__WARN__} unless $warnLevel;
7656 $SIG{__WARN__} = \&DB::dbwarn;
7659 $SIG{__WARN__} = $prevwarn;
7663 } ## end sub warnLevel
7667 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
7668 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
7669 zero lets you use your own C<die()> handler.
7676 $prevdie = $SIG{__DIE__} unless $dieLevel;
7680 # Always set it to dbdie() for non-zero values.
7681 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
7683 # No longer exists, so don't try to use it.
7684 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
7686 # If we've finished initialization, mention that stack dumps
7687 # are enabled, If dieLevel is 1, we won't stack dump if we die
7689 print $OUT "Stack dump during die enabled",
7690 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
7693 # XXX This is probably obsolete, given that diehard() is gone.
7694 print $OUT "Dump printed too.\n" if $dieLevel > 2;
7695 } ## end if ($dieLevel)
7697 # Put the old one back if there was one.
7699 $SIG{__DIE__} = $prevdie;
7700 print $OUT "Default die handler restored.\n";
7704 } ## end sub dieLevel
7706 =head2 C<signalLevel>
7708 Number three in a series: set C<signalLevel> to zero to keep your own
7709 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
7710 takes over and handles them with C<DB::diesignal()>.
7716 $prevsegv = $SIG{SEGV} unless $signalLevel;
7717 $prevbus = $SIG{BUS} unless $signalLevel;
7718 $signalLevel = shift;
7720 $SIG{SEGV} = \&DB::diesignal;
7721 $SIG{BUS} = \&DB::diesignal;
7724 $SIG{SEGV} = $prevsegv;
7725 $SIG{BUS} = $prevbus;
7729 } ## end sub signalLevel
7731 =head1 SUBROUTINE DECODING SUPPORT
7733 These subroutines are used during the C<x> and C<X> commands to try to
7734 produce as much information as possible about a code reference. They use
7735 L<Devel::Peek> to try to find the glob in which this code reference lives
7736 (if it does) - this allows us to actually code references which correspond
7737 to named subroutines (including those aliased via glob assignment).
7739 =head2 C<CvGV_name()>
7741 Wrapper for X<CvGV_name_or_bust>; tries to get the name of a reference
7742 via that routine. If this fails, return the reference again (when the
7743 reference is stringified, it'll come out as "SOMETHING(0X...)").
7749 my $name = CvGV_name_or_bust($in);
7750 defined $name ? $name : $in;
7753 =head2 C<CvGV_name_or_bust> I<coderef>
7755 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
7756 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
7757 find a glob for this ref.
7759 Returns "I<package>::I<glob name>" if the code ref is found in a glob.
7763 sub CvGV_name_or_bust {
7765 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
7766 return unless ref $in;
7767 $in = \&$in; # Hard reference...
7768 eval { require Devel::Peek; 1 } or return;
7769 my $gv = Devel::Peek::CvGV($in) or return;
7770 *$gv{PACKAGE} . '::' . *$gv{NAME};
7771 } ## end sub CvGV_name_or_bust
7775 A utility routine used in various places; finds the file where a subroutine
7776 was defined, and returns that filename and a line-number range.
7778 Tries to use X<@sub> first; if it can't find it there, it tries building a
7779 reference to the subroutine and uses X<CvGV_name_or_bust> to locate it,
7780 loading it into X<@sub> as a side effect (XXX I think). If it can't find it
7781 this way, it brute-force searches X<%sub>, checking for identical references.
7788 return unless defined &$subr;
7789 my $name = CvGV_name_or_bust($subr);
7791 $data = $sub{$name} if defined $name;
7792 return $data if defined $data;
7795 $subr = \&$subr; # Hard reference
7798 $s = $_, last if $subr eq \&$_;
7802 } ## end sub find_sub
7806 A subroutine that uses the utility function X<methods_via> to find all the
7807 methods in the class corresponding to the current reference and in
7814 # Figure out the class - either this is the class or it's a reference
7815 # to something blessed into that class.
7817 $class = ref $class if ref $class;
7821 # Show the methods that this class has.
7822 methods_via( $class, '', 1 );
7824 # Show the methods that UNIVERSAL has.
7825 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
7826 } ## end sub methods
7828 =head2 C<methods_via($class, $prefix, $crawl_upward)>
7830 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
7831 all the parent class methods. C<$class> is the name of the next class to
7832 try; C<$prefix> is the message prefix, which gets built up as we go up the
7833 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
7834 higher in the C<@ISA> tree, 0 if we should stop.
7840 # If we've processed this class already, just quit.
7842 return if $seen{$class}++;
7844 # This is a package that is contributing the methods we're about to print.
7846 my $prepend = $prefix ? "via $prefix: " : '';
7851 # Keep if this is a defined subroutine in this class.
7852 grep { defined &{ ${"${class}::"}{$_} } }
7854 # Extract from all the symbols in this class.
7855 sort keys %{"${class}::"}
7859 # If we printed this already, skip it.
7860 next if $seen{$name}++;
7862 # Print the new method name.
7865 print $DB::OUT "$prepend$name\n";
7866 } ## end for $name (grep { defined...
7868 # If the $crawl_upward argument is false, just quit here.
7869 return unless shift;
7871 # $crawl_upward true: keep going up the tree.
7872 # Find all the classes this one is a subclass of.
7873 for $name ( @{"${class}::ISA"} ) {
7875 # Set up the new prefix.
7876 $prepend = $prefix ? $prefix . " -> $name" : $name;
7878 # Crawl up the tree and keep trying to crawl up.
7879 methods_via( $name, $prepend, 1 );
7881 } ## end sub methods_via
7883 =head2 C<setman> - figure out which command to use to show documentation
7885 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
7890 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|MacOS|NetWare)\z/s
7891 ? "man" # O Happy Day!
7892 : "perldoc"; # Alas, poor unfortunates
7895 =head2 C<runman> - run the appropriate command to show documentation
7897 Accepts a man page name; runs the appropriate command to display it (set up
7898 during debugger initialization). Uses C<DB::system> to avoid mucking up the
7899 program's STDIN and STDOUT.
7906 &system("$doccmd $doccmd");
7910 # this way user can override, like with $doccmd="man -Mwhatever"
7911 # or even just "man " to disable the path check.
7912 unless ( $doccmd eq 'man' ) {
7913 &system("$doccmd $page");
7917 $page = 'perl' if lc($page) eq 'help';
7920 my $man1dir = $Config::Config{'man1dir'};
7921 my $man3dir = $Config::Config{'man3dir'};
7922 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
7924 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
7925 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
7926 chop $manpath if $manpath;
7928 # harmless if missing, I figure
7929 my $oldpath = $ENV{MANPATH};
7930 $ENV{MANPATH} = $manpath if $manpath;
7931 my $nopathopt = $^O =~ /dunno what goes here/;
7936 # I just *know* there are men without -M
7937 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
7942 unless ( $page =~ /^perl\w/ ) {
7943 # do it this way because its easier to slurp in to keep up to date - clunky though.
8082 if (grep { $page eq $_ } @pods) {
8084 CORE::system( $doccmd,
8085 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8087 } ## end if (grep { $page eq $_...
8088 } ## end unless ($page =~ /^perl\w/)
8089 } ## end if (CORE::system($doccmd...
8090 if ( defined $oldpath ) {
8091 $ENV{MANPATH} = $manpath;
8094 delete $ENV{MANPATH};
8098 #use Carp; # This did break, left for debugging
8100 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
8102 Because of the way the debugger interface to the Perl core is designed, any
8103 debugger package globals that C<DB::sub()> requires have to be defined before
8104 any subroutines can be called. These are defined in the second C<BEGIN> block.
8106 This block sets things up so that (basically) the world is sane
8107 before the debugger starts executing. We set up various variables that the
8108 debugger has to have set up before the Perl core starts running:
8112 =item * The debugger's own filehandles (copies of STD and STDOUT for now).
8114 =item * Characters for shell escapes, the recall command, and the history command.
8116 =item * The maximum recursion depth.
8118 =item * The size of a C<w> command's window.
8120 =item * The before-this-line context to be printed in a C<v> (view a window around this line) command.
8122 =item * The fact that we're not in a sub at all right now.
8124 =item * The default SIGINT handler for the debugger.
8126 =item * The appropriate value of the flag in C<$^D> that says the debugger is running
8128 =item * The current debugger recursion level
8130 =item * The list of postponed (XXX define) items and the C<$single> stack
8132 =item * That we want no return values and no subroutine entry/exit trace.
8138 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
8140 BEGIN { # This does not compile, alas. (XXX eh?)
8141 $IN = \*STDIN; # For bugs before DB::OUT has been opened
8142 $OUT = \*STDERR; # For errors before DB::OUT has been opened
8144 # Define characters used by command parsing.
8145 $sh = '!'; # Shell escape (does not work)
8146 $rc = ','; # Recall command (does not work)
8147 @hist = ('?'); # Show history (does not work)
8148 @truehist = (); # Can be saved for replay (per session)
8150 # This defines the point at which you get the 'deep recursion'
8151 # warning. It MUST be defined or the debugger will not load.
8154 # Number of lines around the current one that are shown in the
8158 # How much before-the-current-line context the 'v' command should
8159 # use in calculating the start of the window it will display.
8162 # We're not in any sub yet, but we need this to be a defined value.
8165 # Set up the debugger's interrupt handler. It simply sets a flag
8166 # ($signal) that DB::DB() will check before each command is executed.
8167 $SIG{INT} = \&DB::catch;
8169 # The following lines supposedly, if uncommented, allow the debugger to
8170 # debug itself. Perhaps we can try that someday.
8171 # This may be enabled to debug debugger:
8172 #$warnLevel = 1 unless defined $warnLevel;
8173 #$dieLevel = 1 unless defined $dieLevel;
8174 #$signalLevel = 1 unless defined $signalLevel;
8176 # This is the flag that says "a debugger is running, please call
8177 # DB::DB and DB::sub". We will turn it on forcibly before we try to
8178 # execute anything in the user's context, because we always want to
8180 $db_stop = 0; # Compiler warning ...
8181 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
8183 # This variable records how many levels we're nested in debugging. Used
8184 # Used in the debugger prompt, and in determining whether it's all over or
8186 $level = 0; # Level of recursive debugging
8188 # "Triggers bug (?) in perl if we postpone this until runtime."
8189 # XXX No details on this yet, or whether we should fix the bug instead
8190 # of work around it. Stay tuned.
8191 @postponed = @stack = (0);
8193 # Used to track the current stack depth using the auto-stacked-variable
8195 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
8197 # Don't print return values on exiting a subroutine.
8200 # No extry/exit tracing.
8205 BEGIN { $^W = $ini_warn; } # Switch warnings back
8207 =head1 READLINE SUPPORT - COMPLETION FUNCTION
8211 C<readline> support - adds command completion to basic C<readline>.
8213 Returns a list of possible completions to C<readline> when invoked. C<readline>
8214 will print the longest common substring following the text already entered.
8216 If there is only a single possible completion, C<readline> will use it in full.
8218 This code uses C<map> and C<grep> heavily to create lists of possible
8219 completion. Think LISP in this section.
8225 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
8226 # $text is the text to be completed.
8227 # $line is the incoming line typed by the user.
8228 # $start is the start of the text to be completed in the incoming line.
8229 my ( $text, $line, $start ) = @_;
8231 # Save the initial text.
8232 # The search pattern is current package, ::, extract the next qualifier
8233 # Prefix and pack are set to undef.
8234 my ( $itext, $search, $prefix, $pack ) =
8235 ( $text, "^\Q${'package'}::\E([^:]+)\$" );
8237 =head3 C<b postpone|compile>
8241 =item * Find all the subroutines that might match in this package
8243 =item * Add "postpone", "load", and "compile" as possibles (we may be completing the keyword itself
8245 =item * Include all the rest of the subs that are known
8247 =item * C<grep> out the ones that match the text we have so far
8249 =item * Return this as the list of possible completions
8255 return sort grep /^\Q$text/, ( keys %sub ),
8256 qw(postpone load compile), # subroutines
8257 ( map { /$search/ ? ($1) : () } keys %sub )
8258 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
8262 Get all the possible files from @INC as it currently stands and
8263 select the ones that match the text so far.
8267 return sort grep /^\Q$text/, values %INC # files
8268 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
8270 =head3 C<V> (list variable) and C<m> (list modules)
8272 There are two entry points for these commands:
8274 =head4 Unqualified package names
8276 Get the top-level packages and grab everything that matches the text
8277 so far. For each match, recursively complete the partial packages to
8278 get all possible matching packages. Return this sorted list.
8282 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8283 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
8284 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
8286 =head4 Qualified package names
8288 Take a partially-qualified package and find all subpackages for it
8289 by getting all the subpackages for the package so far, matching all
8290 the subpackages against the text, and discarding all of them which
8291 start with 'main::'. Return this list.
8295 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8296 grep !/^main::/, grep /^\Q$text/,
8297 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () } keys %{ $prefix . '::' }
8298 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
8299 and $text =~ /^(.*[^:])::?(\w*)$/
8302 =head3 C<f> - switch files
8304 Here, we want to get a fully-qualified filename for the C<f> command.
8309 =item 1. The original source file itself
8311 =item 2. A file from C<@INC>
8313 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
8319 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
8320 # We might possibly want to switch to an eval (which has a "filename"
8321 # like '(eval 9)'), so we may need to clean up the completion text
8322 # before proceeding.
8323 $prefix = length($1) - length($text);
8328 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
8329 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
8330 out of C<%main::>, add the initial source file, and extract the ones that
8331 match the completion text so far.
8336 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
8338 } ## end if ($line =~ /^\|*f\s+(.*)/)
8340 =head3 Subroutine name completion
8342 We look through all of the defined subs (the keys of C<%sub>) and
8343 return both all the possible matches to the subroutine name plus
8344 all the matches qualified to the current package.
8348 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
8349 $text = substr $text, 1;
8351 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
8353 map { /$search/ ? ($1) : () }
8356 } ## end if ((substr $text, 0, ...
8358 =head3 Scalar, array, and hash completion: partially qualified package
8360 Much like the above, except we have to do a little more cleanup:
8364 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
8370 =item * Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
8374 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
8378 =item * Figure out the prefix vs. what needs completing.
8382 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
8387 =item * Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
8391 my @out = map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
8396 =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.
8400 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8401 return db_complete( $out[0], $line, $start );
8404 # Return the list of possibles.
8407 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
8413 =head3 Symbol completion: current package or package C<main>.
8417 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
8423 =item * If it's C<main>, delete main to just get C<::> leading.
8427 $pack = ( $package eq 'main' ? '' : $package ) . '::';
8431 =item * We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
8435 $prefix = substr $text, 0, 1;
8436 $text = substr $text, 1;
8440 =item * If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
8444 my @out = map "$prefix$_", grep /^\Q$text/,
8445 ( grep /^_?[a-zA-Z]/, keys %$pack ),
8446 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
8448 =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.
8454 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8455 return db_complete( $out[0], $line, $start );
8458 # Return the list of possibles.
8460 } ## end if ($text =~ /^[\$@%]/)
8464 We use C<option_val()> to look up the current value of the option. If there's
8465 only a single value, we complete the command in such a way that it is a
8466 complete command for setting the option in question. If there are multiple
8467 possible values, we generate a command consisting of the option plus a trailing
8468 question mark, which, if executed, will list the current value of the option.
8472 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
8473 { # Options after space
8474 # We look for the text to be matched in the list of possible options,
8475 # and fetch the current value.
8476 my @out = grep /^\Q$text/, @options;
8477 my $val = option_val( $out[0], undef );
8479 # Set up a 'query option's value' command.
8481 if ( not defined $val or $val =~ /[\n\r]/ ) {
8483 # There's really nothing else we can do.
8486 # We have a value. Create a proper option-setting command.
8487 elsif ( $val =~ /\s/ ) {
8489 # XXX This may be an extraneous variable.
8492 # We'll want to quote the string (because of the embedded
8493 # whtespace), but we want to make sure we don't end up with
8494 # mismatched quote characters. We try several possibilities.
8495 foreach $l ( split //, qq/\"\'\#\|/ ) {
8497 # If we didn't find this quote character in the value,
8498 # quote it using this quote character.
8499 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
8501 } ## end elsif ($val =~ /\s/)
8503 # Don't need any quotes.
8508 # If there were multiple possible values, return '? ', which
8509 # makes the command into a query command. If there was just one,
8510 # have readline append that.
8511 $rl_attribs->{completer_terminator_character} =
8512 ( @out == 1 ? $out : '? ' );
8514 # Return list of possibilities.
8516 } ## end if ((substr $line, 0, ...
8518 =head3 Filename completion
8520 For entering filenames. We simply call C<readline>'s C<filename_list()>
8521 method with the completion text to get the possible completions.
8525 return $term->filename_list($text); # filenames
8527 } ## end sub db_complete
8529 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
8531 Functions that possibly ought to be somewhere else.
8541 print $OUT "Use `q' to quit or `R' to restart. `h q' for details.\n";
8546 If we have $ini_pids, save it in the environment; else remove it from the
8547 environment. Used by the C<R> (restart) command.
8552 if ( defined($ini_pids) ) {
8553 $ENV{PERLDB_PIDS} = $ini_pids;
8556 delete( $ENV{PERLDB_PIDS} );
8558 } ## end sub clean_ENV
8560 # PERLDBf_... flag names from perl.h
8561 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
8564 %DollarCaretP_flags = (
8565 PERLDBf_SUB => 0x01, # Debug sub enter/exit
8566 PERLDBf_LINE => 0x02, # Keep line #
8567 PERLDBf_NOOPT => 0x04, # Switch off optimizations
8568 PERLDBf_INTER => 0x08, # Preserve more data
8569 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
8570 PERLDBf_SINGLE => 0x20, # Start with single-step on
8571 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
8572 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
8573 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
8574 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
8575 PERLDBf_ASSERTION => 0x400, # Debug assertion subs enter/exit
8576 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO, _ASSERTION
8579 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
8582 sub parse_DollarCaretP_flags {
8587 foreach my $f ( split /\s*\|\s*/, $flags ) {
8589 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
8592 elsif ( $f =~ /^(\d+)$/ ) {
8595 elsif ( $f =~ /^DEFAULT$/i ) {
8596 $value = $DollarCaretP_flags{PERLDB_ALL};
8599 $f =~ /^(?:PERLDBf_)?(.*)$/i;
8600 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
8601 unless ( defined $value ) {
8603 "Unrecognized \$^P flag '$f'!\n",
8604 "Acceptable flags are: "
8605 . join( ', ', sort keys %DollarCaretP_flags ),
8606 ", and hexadecimal and decimal numbers.\n"
8616 sub expand_DollarCaretP_flags {
8617 my $DollarCaretP = shift;
8620 my $n = ( 1 << $_ );
8621 ( $DollarCaretP & $n )
8622 ? ( $DollarCaretP_flags_r{$n}
8623 || sprintf( '0x%x', $n ) )
8627 return @bits ? join( '|', @bits ) : 0;
8632 Rerun the current session to:
8634 rerun current position
8636 rerun 4 command number 4
8638 rerun -4 current command minus 4 (go back 4 steps)
8640 Whether this always makes sense, in the current context is unknowable, and is
8641 in part left as a useful exersize for the reader. This sub returns the
8642 appropriate arguments to rerun the current session.
8649 pop(@truehist); # strim
8650 unless (defined $truehist[$i]) {
8651 print "Unable to return to non-existent command: $i\n";
8653 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
8654 my @temp = @truehist; # store
8655 push(@DB::typeahead, @truehist); # saved
8656 @truehist = @hist = (); # flush
8657 @args = &restart(); # setup
8658 &get_list("PERLDB_HIST"); # clean
8659 &set_list("PERLDB_HIST", @temp); # reset
8666 Restarting the debugger is a complex operation that occurs in several phases.
8667 First, we try to reconstruct the command line that was used to invoke Perl
8673 # I may not be able to resurrect you, but here goes ...
8675 "Warning: some settings and command-line options may be lost!\n";
8676 my ( @script, @flags, $cl );
8678 # If warn was on before, turn it on again.
8679 push @flags, '-w' if $ini_warn;
8680 if ( $ini_assertion and @{^ASSERTING} ) {
8682 ( map { /\:\^\(\?\:(.*)\)\$\)/ ? "-A$1" : "-A$_" }
8686 # Rebuild the -I flags that were on the initial
8689 push @flags, '-I', $_;
8692 # Turn on taint if it was on before.
8693 push @flags, '-T' if ${^TAINT};
8695 # Arrange for setting the old INC:
8696 # Save the current @init_INC in the environment.
8697 set_list( "PERLDB_INC", @ini_INC );
8699 # If this was a perl one-liner, go to the "file"
8700 # corresponding to the one-liner read all the lines
8701 # out of it (except for the first one, which is going
8702 # to be added back on again when 'perl -d' runs: that's
8703 # the 'require perl5db.pl;' line), and add them back on
8704 # to the command line to be executed.
8706 for ( 1 .. $#{'::_<-e'} ) { # The first line is PERL5DB
8707 chomp( $cl = ${'::_<-e'}[$_] );
8708 push @script, '-e', $cl;
8710 } ## end if ($0 eq '-e')
8712 # Otherwise we just reuse the original name we had
8720 After the command line has been reconstructed, the next step is to save
8721 the debugger's status in environment variables. The C<DB::set_list> routine
8722 is used to save aggregate variables (both hashes and arrays); scalars are
8723 just popped into environment variables directly.
8727 # If the terminal supported history, grab it and
8728 # save that in the environment.
8729 set_list( "PERLDB_HIST",
8730 $term->Features->{getHistory}
8734 # Find all the files that were visited during this
8735 # session (i.e., the debugger had magic hashes
8736 # corresponding to them) and stick them in the environment.
8737 my @had_breakpoints = keys %had_breakpoints;
8738 set_list( "PERLDB_VISITED", @had_breakpoints );
8740 # Save the debugger options we chose.
8741 set_list( "PERLDB_OPT", %option );
8742 # set_list( "PERLDB_OPT", options2remember() );
8744 # Save the break-on-loads.
8745 set_list( "PERLDB_ON_LOAD", %break_on_load );
8749 The most complex part of this is the saving of all of the breakpoints. They
8750 can live in an awful lot of places, and we have to go through all of them,
8751 find the breakpoints, and then save them in the appropriate environment
8752 variable via C<DB::set_list>.
8756 # Go through all the breakpoints and make sure they're
8759 for ( 0 .. $#had_breakpoints ) {
8761 # We were in this file.
8762 my $file = $had_breakpoints[$_];
8764 # Grab that file's magic line hash.
8765 *dbline = $main::{ '_<' . $file };
8767 # Skip out if it doesn't exist, or if the breakpoint
8768 # is in a postponed file (we'll do postponed ones
8770 next unless %dbline or $postponed_file{$file};
8772 # In an eval. This is a little harder, so we'll
8773 # do more processing on that below.
8774 ( push @hard, $file ), next
8775 if $file =~ /^\(\w*eval/;
8777 # XXX I have no idea what this is doing. Yet.
8779 @add = %{ $postponed_file{$file} }
8780 if $postponed_file{$file};
8782 # Save the list of all the breakpoints for this file.
8783 set_list( "PERLDB_FILE_$_", %dbline, @add );
8784 } ## end for (0 .. $#had_breakpoints)
8786 # The breakpoint was inside an eval. This is a little
8787 # more difficult. XXX and I don't understand it.
8789 # Get over to the eval in question.
8790 *dbline = $main::{ '_<' . $_ };
8791 my ( $quoted, $sub, %subs, $line ) = quotemeta $_;
8792 for $sub ( keys %sub ) {
8793 next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/;
8794 $subs{$sub} = [ $1, $2 ];
8798 "No subroutines in $_, ignoring breakpoints.\n";
8801 LINES: for $line ( keys %dbline ) {
8803 # One breakpoint per sub only:
8804 my ( $offset, $sub, $found );
8805 SUBS: for $sub ( keys %subs ) {
8808 $line # Not after the subroutine
8810 not defined $offset # Not caught
8816 $offset = $line - $subs{$sub}->[0];
8817 $offset = "+$offset", last SUBS
8819 } ## end if ($subs{$sub}->[1] >=...
8820 } ## end for $sub (keys %subs)
8821 if ( defined $offset ) {
8822 $postponed{$found} =
8823 "break $offset if $dbline{$line}";
8827 "Breakpoint in $_:$line ignored: after all the subroutines.\n";
8829 } ## end for $line (keys %dbline)
8830 } ## end for (@hard)
8832 # Save the other things that don't need to be
8834 set_list( "PERLDB_POSTPONE", %postponed );
8835 set_list( "PERLDB_PRETYPE", @$pretype );
8836 set_list( "PERLDB_PRE", @$pre );
8837 set_list( "PERLDB_POST", @$post );
8838 set_list( "PERLDB_TYPEAHEAD", @typeahead );
8840 # We are oficially restarting.
8841 $ENV{PERLDB_RESTART} = 1;
8843 # We are junking all child debuggers.
8844 delete $ENV{PERLDB_PIDS}; # Restore ini state
8846 # Set this back to the initial pid.
8847 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
8851 After all the debugger status has been saved, we take the command we built up
8852 and then return it, so we can C<exec()> it. The debugger will spot the
8853 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
8854 from the environment.
8858 # And run Perl again. Add the "-d" flag, all the
8859 # flags we built up, the script (whether a one-liner
8860 # or a file), add on the -emacs flag for a slave editor,
8861 # and then the old arguments.
8863 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
8867 =head1 END PROCESSING - THE C<END> BLOCK
8869 Come here at the very end of processing. We want to go into a
8870 loop where we allow the user to enter commands and interact with the
8871 debugger, but we don't want anything else to execute.
8873 First we set the C<$finished> variable, so that some commands that
8874 shouldn't be run after the end of program quit working.
8876 We then figure out whether we're truly done (as in the user entered a C<q>
8877 command, or we finished execution while running nonstop). If we aren't,
8878 we set C<$single> to 1 (causing the debugger to get control again).
8880 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...">
8881 message and returns control to the debugger. Repeat.
8883 When the user finally enters a C<q> command, C<$fall_off_end> is set to
8884 1 and the C<END> block simply exits with C<$single> set to 0 (don't
8885 break, run to completion.).
8890 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
8891 $fall_off_end = 1 unless $inhibit_exit;
8893 # Do not stop in at_exit() and destructors on exit:
8894 $DB::single = !$fall_off_end && !$runnonstop;
8895 DB::fake::at_exit() unless $fall_off_end or $runnonstop;
8898 =head1 PRE-5.8 COMMANDS
8900 Some of the commands changed function quite a bit in the 5.8 command
8901 realignment, so much so that the old code had to be replaced completely.
8902 Because we wanted to retain the option of being able to go back to the
8903 former command set, we moved the old code off to this section.
8905 There's an awful lot of duplicated code here. We've duplicated the
8906 comments to keep things clear.
8910 Does nothing. Used to 'turn off' commands.
8914 sub cmd_pre580_null {
8919 =head2 Old C<a> command.
8921 This version added actions if you supplied them, and deleted them
8930 # Argument supplied. Add the action.
8931 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
8933 # If the line isn't there, use the current line.
8937 # If there is an action ...
8940 # ... but the line isn't breakable, skip it.
8941 if ( $dbline[$i] == 0 ) {
8942 print $OUT "Line $i may not have an action.\n";
8946 # ... and the line is breakable:
8947 # Mark that there's an action in this file.
8948 $had_breakpoints{$filename} |= 2;
8950 # Delete any current action.
8951 $dbline{$i} =~ s/\0[^\0]*//;
8953 # Add the new action, continuing the line as needed.
8954 $dbline{$i} .= "\0" . action($j);
8956 } ## end if (length $j)
8958 # No action supplied.
8961 # Delete the action.
8962 $dbline{$i} =~ s/\0[^\0]*//;
8964 # Mark as having no break or action if nothing's left.
8965 delete $dbline{$i} if $dbline{$i} eq '';
8967 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
8968 } ## end sub cmd_pre580_a
8970 =head2 Old C<b> command
8982 if ( $cmd =~ /^load\b\s*(.*)/ ) {
8988 # b compile|postpone <some sub> [<condition>]
8989 # The interpreter actually traps this one for us; we just put the
8990 # necessary condition in the %postponed hash.
8991 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
8993 # Capture the condition if there is one. Make it true if none.
8994 my $cond = length $3 ? $3 : '1';
8996 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
8997 # if it was 'compile'.
8998 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
9000 # De-Perl4-ify the name - ' separators to ::.
9001 $subname =~ s/\'/::/g;
9003 # Qualify it into the current package unless it's already qualified.
9004 $subname = "${'package'}::" . $subname
9005 unless $subname =~ /::/;
9007 # Add main if it starts with ::.
9008 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
9010 # Save the break type for this sub.
9011 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
9012 } ## end elsif ($cmd =~ ...
9014 # b <sub name> [<condition>]
9015 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
9017 my $cond = length $2 ? $2 : '1';
9018 &cmd_b_sub( $subname, $cond );
9021 # b <line> [<condition>].
9022 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9023 my $i = $1 || $dbline;
9024 my $cond = length $2 ? $2 : '1';
9025 &cmd_b_line( $i, $cond );
9027 } ## end sub cmd_pre580_b
9029 =head2 Old C<D> command.
9031 Delete all breakpoints unconditionally.
9038 if ( $cmd =~ /^\s*$/ ) {
9039 print $OUT "Deleting all breakpoints...\n";
9041 # %had_breakpoints lists every file that had at least one
9044 for $file ( keys %had_breakpoints ) {
9046 # Switch to the desired file temporarily.
9047 local *dbline = $main::{ '_<' . $file };
9052 # For all lines in this file ...
9053 for ( $i = 1 ; $i <= $max ; $i++ ) {
9055 # If there's a breakpoint or action on this line ...
9056 if ( defined $dbline{$i} ) {
9058 # ... remove the breakpoint.
9059 $dbline{$i} =~ s/^[^\0]+//;
9060 if ( $dbline{$i} =~ s/^\0?$// ) {
9062 # Remove the entry altogether if no action is there.
9065 } ## end if (defined $dbline{$i...
9066 } ## end for ($i = 1 ; $i <= $max...
9068 # If, after we turn off the "there were breakpoints in this file"
9069 # bit, the entry in %had_breakpoints for this file is zero,
9070 # we should remove this file from the hash.
9071 if ( not $had_breakpoints{$file} &= ~1 ) {
9072 delete $had_breakpoints{$file};
9074 } ## end for $file (keys %had_breakpoints)
9076 # Kill off all the other breakpoints that are waiting for files that
9077 # haven't been loaded yet.
9079 undef %postponed_file;
9080 undef %break_on_load;
9081 } ## end if ($cmd =~ /^\s*$/)
9082 } ## end sub cmd_pre580_D
9084 =head2 Old C<h> command
9086 Print help. Defaults to printing the long-form help; the 5.8 version
9087 prints the summary by default.
9095 # Print the *right* help, long format.
9096 if ( $cmd =~ /^\s*$/ ) {
9097 print_help($pre580_help);
9100 # 'h h' - explicitly-requested summary.
9101 elsif ( $cmd =~ /^h\s*/ ) {
9102 print_help($pre580_summary);
9105 # Find and print a command's help.
9106 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
9107 my $asked = $1; # for proper errmsg
9108 my $qasked = quotemeta($asked); # for searching
9109 # XXX: finds CR but not <CR>
9113 (?:[IB]<) # Optional markup
9114 $qasked # The command name
9121 ( # The command help:
9123 (?:[IB]<) # Optional markup
9124 $qasked # The command name
9125 ([\s\S]*?) # Lines starting with tabs
9129 ) # Line not starting with space
9130 # (Next command's help)
9134 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
9138 print_help("B<$asked> is not a debugger command.\n");
9140 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
9141 } ## end sub cmd_pre580_h
9143 =head2 Old C<W> command
9145 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
9153 # Delete all watch expressions.
9154 if ( $cmd =~ /^$/ ) {
9156 # No watching is going on.
9159 # Kill all the watch expressions and values.
9160 @to_watch = @old_watch = ();
9163 # Add a watch expression.
9164 elsif ( $cmd =~ /^(.*)/s ) {
9166 # add it to the list to be watched.
9169 # Get the current value of the expression.
9170 # Doesn't handle expressions returning list values!
9173 $val = ( defined $val ) ? "'$val'" : 'undef';
9176 push @old_watch, $val;
9178 # We're watching stuff.
9181 } ## end elsif ($cmd =~ /^(.*)/s)
9182 } ## end sub cmd_pre580_W
9184 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
9186 The debugger used to have a bunch of nearly-identical code to handle
9187 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
9188 C<cmd_prepost> unify all this into one set of code to handle the
9189 appropriate actions.
9191 =head2 C<cmd_pre590_prepost>
9193 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
9194 do something destructive. In pre 5.8 debuggers, the default action was to
9195 delete all the actions.
9199 sub cmd_pre590_prepost {
9201 my $line = shift || '*';
9204 return &cmd_prepost( $cmd, $line, $dbline );
9205 } ## end sub cmd_pre590_prepost
9207 =head2 C<cmd_prepost>
9209 Actually does all the handling foe C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
9210 Since the lists of actions are all held in arrays that are pointed to by
9211 references anyway, all we have to do is pick the right array reference and
9212 then use generic code to all, delete, or list actions.
9219 # No action supplied defaults to 'list'.
9220 my $line = shift || '?';
9222 # Figure out what to put in the prompt.
9225 # Make sure we have some array or another to address later.
9226 # This means that if ssome reason the tests fail, we won't be
9227 # trying to stash actions or delete them from the wrong place.
9230 # < - Perl code to run before prompt.
9231 if ( $cmd =~ /^\</o ) {
9232 $which = 'pre-perl';
9236 # > - Perl code to run after prompt.
9237 elsif ( $cmd =~ /^\>/o ) {
9238 $which = 'post-perl';
9242 # { - first check for properly-balanced braces.
9243 elsif ( $cmd =~ /^\{/o ) {
9244 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
9246 "$cmd is now a debugger command\nuse `;$cmd' if you mean Perl code\n";
9249 # Properly balanced. Pre-prompt debugger actions.
9251 $which = 'pre-debugger';
9254 } ## end elsif ( $cmd =~ /^\{/o )
9256 # Did we find something that makes sense?
9258 print $OUT "Confused by command: $cmd\n";
9265 if ( $line =~ /^\s*\?\s*$/o ) {
9268 # Nothing there. Complain.
9269 print $OUT "No $which actions.\n";
9273 # List the actions in the selected list.
9274 print $OUT "$which commands:\n";
9275 foreach my $action (@$aref) {
9276 print $OUT "\t$cmd -- $action\n";
9279 } ## end if ( $line =~ /^\s*\?\s*$/o)
9281 # Might be a delete.
9283 if ( length($cmd) == 1 ) {
9284 if ( $line =~ /^\s*\*\s*$/o ) {
9286 # It's a delete. Get rid of the old actions in the
9289 print $OUT "All $cmd actions cleared.\n";
9293 # Replace all the actions. (This is a <, >, or {).
9294 @$aref = action($line);
9296 } ## end if ( length($cmd) == 1)
9297 elsif ( length($cmd) == 2 ) {
9299 # Add the action to the line. (This is a <<, >>, or {{).
9300 push @$aref, action($line);
9304 # <<<, >>>>, {{{{{{ ... something not a command.
9306 "Confused by strange length of $which command($cmd)...\n";
9308 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
9310 } ## end sub cmd_prepost
9314 Contains the C<at_exit> routine that the debugger uses to issue the
9315 C<Debugged program terminated ...> message after the program completes. See
9316 the C<END> block documentation for more details.
9323 "Debugged program terminated. Use `q' to quit or `R' to restart.";
9326 package DB; # Do not trace this 1; below!