3 C<perl5db.pl> - the perl debugger
7 perl -d your_Perl_script
11 C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when
12 you invoke a script with C<perl -d>. This documentation tries to outline the
13 structure and services provided by C<perl5db.pl>, and to describe how you
18 The debugger can look pretty forbidding to many Perl programmers. There are
19 a number of reasons for this, many stemming out of the debugger's history.
21 When the debugger was first written, Perl didn't have a lot of its nicer
22 features - no references, no lexical variables, no closures, no object-oriented
23 programming. So a lot of the things one would normally have done using such
24 features was done using global variables, globs and the C<local()> operator
27 Some of these have survived into the current debugger; a few of the more
28 interesting and still-useful idioms are noted in this section, along with notes
29 on the comments themselves.
31 =head2 Why not use more lexicals?
33 Experienced Perl programmers will note that the debugger code tends to use
34 mostly package globals rather than lexically-scoped variables. This is done
35 to allow a significant amount of control of the debugger from outside the
38 Unfortunately, though the variables are accessible, they're not well
39 documented, so it's generally been a decision that hasn't made a lot of
40 difference to most users. Where appropriate, comments have been added to
41 make variables more accessible and usable, with the understanding that these
42 i<are> debugger internals, and are therefore subject to change. Future
43 development should probably attempt to replace the globals with a well-defined
44 API, but for now, the variables are what we've got.
46 =head2 Automated variable stacking via C<local()>
48 As you may recall from reading L<perlop>, the C<local()> operator makes a
49 temporary copy of a variable in the current scope. When the scope ends, the
50 old copy is restored. This is often used in the debugger to handle the
51 automatic stacking of variables during recursive calls:
56 # Do some stuff, then ...
60 What happens is that on entry to the subroutine, C<$some_global> is localized,
61 then altered. When the subroutine returns, Perl automatically undoes the
62 locaization, restoring the previous value. Voila, automatic stack management.
64 The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>,
65 which lets the debugger get control inside of C<eval>'ed code. The debugger
66 localizes a saved copy of C<$@> inside the subroutine, which allows it to
67 keep C<$@> safe until it C<DB::eval> returns, at which point the previous
68 value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep
69 track of C<$@> inside C<eval>s which C<eval> other C<eval's>.
71 In any case, watch for this pattern. It occurs fairly often.
75 This is used to cleverly reverse the sense of a logical test depending on
76 the value of an auxillary variable. For instance, the debugger's C<S>
77 (search for subroutines by pattern) allows you to negate the pattern
80 # Find all non-'foo' subs:
83 Boolean algebra states that the truth table for XOR looks like this:
89 (! not present and no match) --> false, don't print
93 (! not present and matches) --> true, print
97 (! present and no match) --> true, print
101 (! present and matches) --> false, don't print
105 As you can see, the first pair applies when C<!> isn't supplied, and
106 the second pair applies when it isn't. The XOR simply allows us to
107 compact a more complicated if-then-elseif-else into a more elegant
108 (but perhaps overly clever) single test. After all, it needed this
111 =head2 FLAGS, FLAGS, FLAGS
113 There is a certain C programming legacy in the debugger. Some variables,
114 such as C<$single>, C<$trace>, and C<$frame>, have "magical" values composed
115 of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces
116 of state to be stored independently in a single scalar.
122 is checking to see if the appropriate bit is on. Since each bit can be
123 "addressed" independently in this way, C<$scalar> is acting sort of like
124 an array of bits. Obviously, since the contents of C<$scalar> are just a
125 bit-pattern, we can save and restore it easily (it will just look like
128 The problem, is of course, that this tends to leave magic numbers scattered
129 all over your program whenever a bit is set, cleared, or checked. So why do
135 =item * First, doing an arithmetical or bitwise operation on a scalar is
136 just about the fastest thing you can do in Perl: C<use constant> actually
137 creates a subroutine call, and array hand hash lookups are much slower. Is
138 this over-optimization at the expense of readability? Possibly, but the
139 debugger accesses these variables a I<lot>. Any rewrite of the code will
140 probably have to benchmark alternate implementations and see which is the
141 best balance of readability and speed, and then document how it actually
144 =item * Second, it's very easy to serialize a scalar number. This is done in
145 the restart code; the debugger state variables are saved in C<%ENV> and then
146 restored when the debugger is restarted. Having them be just numbers makes
149 =item * Third, some of these variables are being shared with the Perl core
150 smack in the middle of the interpreter's execution loop. It's much faster for
151 a C program (like the interpreter) to check a bit in a scalar than to access
152 several different variables (or a Perl array).
156 =head2 What are those C<XXX> comments for?
158 Any comment containing C<XXX> means that the comment is either somewhat
159 speculative - it's not exactly clear what a given variable or chunk of
160 code is doing, or that it is incomplete - the basics may be clear, but the
161 subtleties are not completely documented.
163 Send in a patch if you can clear up, fill out, or clarify an C<XXX>.
165 =head1 DATA STRUCTURES MAINTAINED BY CORE
167 There are a number of special data structures provided to the debugger by
168 the Perl interpreter.
170 The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline> via glob
171 assignment) contains the text from C<$filename>, with each element
172 corresponding to a single line of C<$filename>.
174 The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
175 assignment) contains breakpoints and actions. The keys are line numbers;
176 you can set individual values, but not the whole hash. The Perl interpreter
177 uses this hash to determine where breakpoints have been set. Any true value is
178 considered to be a breakpoint; C<perl5db.pl> uses "$break_condition\0$action".
179 Values are magical in numeric context: 1 if the line is breakable, 0 if not.
181 The scalar ${'_<'.$filename} contains $filename XXX What?
183 =head1 DEBUGGER STARTUP
185 When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
186 non-interactive sessions, C<.perldb> for interactive ones) that can set a number
187 of options. In addition, this file may define a subroutine C<&afterinit>
188 that will be executed (in the debugger's context) after the debugger has
191 Next, it checks the C<PERLDB_OPTS> environment variable and treats its
192 contents as the argument of a debugger <C<O> command.
194 =head2 STARTUP-ONLY OPTIONS
196 The foillowing options can only be specified at startup.
197 To set them in your rcfile, add a call to
198 C<&parse_options("optionName=new_value")>.
204 the TTY to use for debugging i/o.
208 if set, goes in NonStop mode. On interrupt, if TTY is not set,
209 uses the value of noTTY or "/tmp/perldbtty$$" to find TTY using
210 Term::Rendezvous. Current variant is to have the name of TTY in this
215 If false, a dummy ReadLine is used, so you can debug
216 ReadLine applications.
220 if true, no i/o is performed until interrupt.
224 file or pipe to print line number info to. If it is a
225 pipe, a short "emacs like" message is used.
229 host:port to connect to on remote host for remote debugging.
235 &parse_options("NonStop=1 LineInfo=db.out");
236 sub afterinit { $trace = 1; }
238 The script will run without human intervention, putting trace
239 information into C<db.out>. (If you interrupt it, you had better
240 reset C<LineInfo> to something "interactive"!)
242 =head1 INTERNALS DESCRIPTION
244 =head2 DEBUGGER INTERFACE VARIABLES
246 Perl supplies the values for C<%sub>. It effectively inserts
247 a C<&DB'DB();> in front of each place that can have a
248 breakpoint. At each subroutine call, it calls C<&DB::sub> with
249 C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
250 {require 'perl5db.pl'}> before the first line.
252 After each C<require>d file is compiled, but before it is executed, a
253 call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
254 is the expanded name of the C<require>d file (as found via C<%INC>).
256 =head3 IMPORTANT INTERNAL VARIABLES
260 Used to control when the debugger will attempt to acquire another TTY to be
265 =item * 1 - on C<fork()>
267 =item * 2 - debugger is started inside debugger
269 =item * 4 - on startup
275 The value -2 indicates that no return value should be printed.
276 Any other positive value causes C<DB::sub> to print return values.
280 The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
281 contents of C<@_> when C<DB::eval> is called.
285 Determines what messages (if any) will get printed when a subroutine (or eval)
286 is entered or exited.
290 =item * 0 - No enter/exit messages
292 =item * 1 - Print "entering" messages on subroutine entry
294 =item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
296 =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.
298 =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.
300 =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.
304 To get everything, use C<$frame=30> (or C<o f-30> as a debugger command).
305 The debugger internally juggles the value of C<$frame> during execution to
306 protect external modules that the debugger uses from getting traced.
310 Tracks current debugger nesting level. Used to figure out how many
311 C<E<lt>E<gt>> pairs to surround the line number with when the debugger
312 outputs a prompt. Also used to help determine if the program has finished
313 during command parsing.
315 =head4 C<$onetimeDump>
317 Controls what (if anything) C<DB::eval()> will print after evaluating an
322 =item * C<undef> - don't print anything
324 =item * C<dump> - use C<dumpvar.pl> to display the value returned
326 =item * C<methods> - print the methods callable on the first item returned
330 =head4 C<$onetimeDumpDepth>
332 Controls how far down C<dumpvar.pl> will go before printing '...' while
333 dumping a structure. Numeric. If C<undef>, print all levels.
337 Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
338 which is called before every statement, checks this and puts the user into
339 command mode if it finds C<$signal> set to a true value.
343 Controls behavior during single-stepping. Stacked in C<@stack> on entry to
344 each subroutine; popped again at the end of each subroutine.
348 =item * 0 - run continuously.
350 =item * 1 - single-step, go into subs. The 's' command.
352 =item * 2 - single-step, don't go into subs. The 'n' command.
354 =item * 4 - print current sub depth (turned on to force this when "too much
361 Controls the output of trace information.
365 =item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
367 =item * 2 - watch expressions are active
369 =item * 4 - user defined a C<watchfunction()> in C<afterinit()>
373 =head4 C<$slave_editor>
375 1 if C<LINEINFO> was directed to a pipe; 0 otherwise.
379 Stack of filehandles that C<DB::readline()> will read commands from.
380 Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
384 Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
385 supplied by the Perl interpreter to the debugger. Contains the source.
389 Previous values of watch expressions. First set when the expression is
390 entered; reset whenever the watch expression changes.
394 Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
395 so that the debugger can substitute safe values while it's running, and
396 restore them when it returns control.
400 Saves the current value of C<$single> on entry to a subroutine.
401 Manipulated by the C<c> command to turn off tracing in all subs above the
406 The 'watch' expressions: to be evaluated before each line is executed.
410 The typeahead buffer, used by C<DB::readline>.
414 Command aliases. Stored as character strings to be substituted for a command
417 =head4 C<%break_on_load>
419 Keys are file names, values are 1 (break when this file is loaded) or undef
420 (don't break when it is loaded).
424 Keys are line numbers, values are "condition\0action". If used in numeric
425 context, values are 0 if not breakable, 1 if breakable, no matter what is
426 in the actual hash entry.
428 =head4 C<%had_breakpoints>
430 Keys are file names; values are bitfields:
434 =item * 1 - file has a breakpoint in it.
436 =item * 2 - file has an action in it.
440 A zero or undefined value means this file has neither.
444 Stores the debugger options. These are character string values.
448 Saves breakpoints for code that hasn't been compiled yet.
449 Keys are subroutine names, values are:
453 =item * 'compile' - break when this sub is compiled
455 =item * 'break +0 if <condition>' - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
459 =head4 C<%postponed_file>
461 This hash keeps track of breakpoints that need to be set for files that have
462 not yet been compiled. Keys are filenames; values are references to hashes.
463 Each of these hashes is keyed by line number, and its values are breakpoint
464 definitions ("condition\0action").
466 =head1 DEBUGGER INITIALIZATION
468 The debugger's initialization actually jumps all over the place inside this
469 package. This is because there are several BEGIN blocks (which of course
470 execute immediately) spread through the code. Why is that?
472 The debugger needs to be able to change some things and set some things up
473 before the debugger code is compiled; most notably, the C<$deep> variable that
474 C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
475 debugger has to turn off warnings while the debugger code is compiled, but then
476 restore them to their original setting before the program being debugged begins
479 The first C<BEGIN> block simply turns off warnings by saving the current
480 setting of C<$^W> and then setting it to zero. The second one initializes
481 the debugger variables that are needed before the debugger begins executing.
482 The third one puts C<$^X> back to its former value.
484 We'll detail the second C<BEGIN> block later; just remember that if you need
485 to initialize something before the debugger starts really executing, that's
492 # Debugger for Perl 5.00x; perl5db.pl patch level:
494 $header = "perl5db.pl version $VERSION";
496 =head1 DEBUGGER ROUTINES
500 This function replaces straight C<eval()> inside the debugger; it simplifies
501 the process of evaluating code in the user's context.
503 The code to be evaluated is passedd via the package global variable
504 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
506 We preserve the current settings of X<C<$trace>>, X<C<$single>>, and X<C<$^D>>;
507 add the X<C<$usercontext>> (that's the preserved values of C<$@>, C<$!>,
508 C<$^E>, C<$,>, C<$/>, C<$\>, and C<$^W>, grabbed when C<DB::DB> got control,
509 and the user's current package) and a add a newline before we do the C<eval()>.
510 This causes the proper context to be used when the eval is actually done.
511 Afterward, we restore C<$trace>, C<$single>, and C<$^D>.
513 Next we need to handle C<$@> without getting confused. We save C<$@> in a
514 local lexical, localize C<$saved[0]> (which is where C<save()> will put
515 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
516 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
517 considered sane by the debugger. If there was an C<eval()> error, we print
518 it on the debugger's output. If X<C<$onetimedump>> is defined, we call
519 X<C<dumpit>> if it's set to 'dump', or X<C<methods>> if it's set to
520 'methods'. Setting it to something else causes the debugger to do the eval
521 but not print the result - handy if you want to do something else with it
522 (the "watch expressions" code does this to get the value of the watch
523 expression but not show it unless it matters).
525 In any case, we then return the list of output from C<eval> to the caller,
526 and unwinding restores the former version of C<$@> in C<@saved> as well
527 (the localization of C<$saved[0]> goes away at the end of this scope).
529 =head3 Parameters and variables influencing execution of DB::eval()
531 C<DB::eval> isn't parameterized in the standard way; this is to keep the
532 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
533 The variables listed below influence C<DB::eval()>'s execution directly.
537 =item C<$evalarg> - the thing to actually be eval'ed
539 =item C<$trace> - Current state of execution tracing (see X<$trace>)
541 =item C<$single> - Current state of single-stepping (see X<$single>)
543 =item C<$onetimeDump> - what is to be displayed after the evaluation
545 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
549 The following variables are altered by C<DB::eval()> during its execution. They
550 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
554 =item C<@res> - used to capture output from actual C<eval>.
556 =item C<$otrace> - saved value of C<$trace>.
558 =item C<$osingle> - saved value of C<$single>.
560 =item C<$od> - saved value of C<$^D>.
562 =item C<$saved[0]> - saved value of C<$@>.
564 =item $\ - for output of C<$@> if there is an evaluation error.
568 =head3 The problem of lexicals
570 The context of C<DB::eval()> presents us with some problems. Obviously,
571 we want to be 'sandboxed' away from the debugger's internals when we do
572 the eval, but we need some way to control how punctuation variables and
573 debugger globals are used.
575 We can't use local, because the code inside C<DB::eval> can see localized
576 variables; and we can't use C<my> either for the same reason. The code
577 in this routine compromises and uses C<my>.
579 After this routine is over, we don't have user code executing in the debugger's
580 context, so we can use C<my> freely.
584 ############################################## Begin lexical danger zone
586 # 'my' variables used here could leak into (that is, be visible in)
587 # the context that the code being evaluated is executing in. This means that
588 # the code could modify the debugger's variables.
590 # Fiddling with the debugger's context could be Bad. We insulate things as
595 # 'my' would make it visible from user code
596 # but so does local! --tchrist
597 # Remember: this localizes @DB::res, not @main::res.
600 # Try to keep the user code from messing with us. Save these so that
601 # even if the eval'ed code changes them, we can put them back again.
602 # Needed because the user could refer directly to the debugger's
603 # package globals (and any 'my' variables in this containing scope)
604 # inside the eval(), and we want to try to stay safe.
605 local $otrace = $trace;
606 local $osingle = $single;
609 # Untaint the incoming eval() argument.
610 { ($evalarg) = $evalarg =~ /(.*)/s; }
612 # $usercontext built in DB::DB near the comment
613 # "set up the context for DB::eval ..."
614 # Evaluate and save any results.
616 eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
618 # Restore those old values.
624 # Save the current value of $@, and preserve it in the debugger's copy
625 # of the saved precious globals.
628 # Since we're only saving $@, we only have to localize the array element
629 # that it will be stored in.
630 local $saved[0]; # Preserve the old value of $@
633 # Now see whether we need to report an error back to the user.
639 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
640 # are package globals.
641 elsif ($onetimeDump) {
642 if ($onetimeDump eq 'dump') {
643 local $option{dumpDepth} = $onetimedumpDepth
644 if defined $onetimedumpDepth;
647 elsif ($onetimeDump eq 'methods') {
650 } ## end elsif ($onetimeDump)
654 ############################################## End lexical danger zone
656 # After this point it is safe to introduce lexicals.
657 # The code being debugged will be executing in its own context, and
658 # can't see the inside of the debugger.
660 # However, one should not overdo it: leave as much control from outside as
661 # possible. If you make something a lexical, it's not going to be addressable
662 # from outside the debugger even if you know its name.
664 # This file is automatically included if you do perl -d.
665 # It's probably not useful to include this yourself.
667 # Before venturing further into these twisty passages, it is
668 # wise to read the perldebguts man page or risk the ire of dragons.
670 # (It should be noted that perldebguts will tell you a lot about
671 # the uderlying mechanics of how the debugger interfaces into the
672 # Perl interpreter, but not a lot about the debugger itself. The new
673 # comments in this code try to address this problem.)
675 # Note that no subroutine call is possible until &DB::sub is defined
676 # (for subroutines defined outside of the package DB). In fact the same is
677 # true if $deep is not defined.
679 # $Log: perldb.pl,v $
681 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
683 # modified Perl debugger, to be run from Emacs in perldb-mode
684 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
685 # Johan Vromans -- upgrade to 4.0 pl 10
686 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
688 # (We have made efforts to clarify the comments in the change log
689 # in other places; some of them may seem somewhat obscure as they
690 # were originally written, and explaining them away from the code
691 # in question seems conterproductive.. -JM)
693 ########################################################################
695 # + A lot of things changed after 0.94. First of all, core now informs
696 # debugger about entry into XSUBs, overloaded operators, tied operations,
697 # BEGIN and END. Handy with `O f=2'.
698 # + This can make debugger a little bit too verbose, please be patient
699 # and report your problems promptly.
700 # + Now the option frame has 3 values: 0,1,2. XXX Document!
701 # + Note that if DESTROY returns a reference to the object (or object),
702 # the deletion of data may be postponed until the next function call,
703 # due to the need to examine the return value.
706 # + `v' command shows versions.
709 # + `v' command shows version of readline.
710 # primitive completion works (dynamic variables, subs for `b' and `l',
711 # options). Can `p %var'
712 # + Better help (`h <' now works). New commands <<, >>, {, {{.
713 # {dump|print}_trace() coded (to be able to do it from <<cmd).
714 # + `c sub' documented.
715 # + At last enough magic combined to stop after the end of debuggee.
716 # + !! should work now (thanks to Emacs bracket matching an extra
717 # `]' in a regexp is caught).
718 # + `L', `D' and `A' span files now (as documented).
719 # + Breakpoints in `require'd code are possible (used in `R').
720 # + Some additional words on internal work of debugger.
721 # + `b load filename' implemented.
722 # + `b postpone subr' implemented.
723 # + now only `q' exits debugger (overwritable on $inhibit_exit).
724 # + When restarting debugger breakpoints/actions persist.
725 # + Buglet: When restarting debugger only one breakpoint/action per
726 # autoloaded function persists.
728 # Changes: 0.97: NonStop will not stop in at_exit().
729 # + Option AutoTrace implemented.
730 # + Trace printed differently if frames are printed too.
731 # + new `inhibitExit' option.
732 # + printing of a very long statement interruptible.
733 # Changes: 0.98: New command `m' for printing possible methods
734 # + 'l -' is a synonym for `-'.
735 # + Cosmetic bugs in printing stack trace.
736 # + `frame' & 8 to print "expanded args" in stack trace.
737 # + Can list/break in imported subs.
738 # + new `maxTraceLen' option.
739 # + frame & 4 and frame & 8 granted.
741 # + nonstoppable lines do not have `:' near the line number.
742 # + `b compile subname' implemented.
743 # + Will not use $` any more.
744 # + `-' behaves sane now.
745 # Changes: 0.99: Completion for `f', `m'.
746 # + `m' will remove duplicate names instead of duplicate functions.
747 # + `b load' strips trailing whitespace.
748 # completion ignores leading `|'; takes into account current package
749 # when completing a subroutine name (same for `l').
750 # Changes: 1.07: Many fixed by tchrist 13-March-2000
752 # + Added bare minimal security checks on perldb rc files, plus
753 # comments on what else is needed.
754 # + Fixed the ornaments that made "|h" completely unusable.
755 # They are not used in print_help if they will hurt. Strip pod
756 # if we're paging to less.
757 # + Fixed mis-formatting of help messages caused by ornaments
758 # to restore Larry's original formatting.
759 # + Fixed many other formatting errors. The code is still suboptimal,
760 # and needs a lot of work at restructuring. It's also misindented
762 # + Fixed bug where trying to look at an option like your pager
764 # + Fixed some $? processing. Note: if you use csh or tcsh, you will
765 # lose. You should consider shell escapes not using their shell,
766 # or else not caring about detailed status. This should really be
767 # unified into one place, too.
768 # + Fixed bug where invisible trailing whitespace on commands hoses you,
769 # tricking Perl into thinking you weren't calling a debugger command!
770 # + Fixed bug where leading whitespace on commands hoses you. (One
771 # suggests a leading semicolon or any other irrelevant non-whitespace
772 # to indicate literal Perl code.)
773 # + Fixed bugs that ate warnings due to wrong selected handle.
774 # + Fixed a precedence bug on signal stuff.
775 # + Fixed some unseemly wording.
776 # + Fixed bug in help command trying to call perl method code.
777 # + Fixed to call dumpvar from exception handler. SIGPIPE killed us.
779 # + Added some comments. This code is still nasty spaghetti.
780 # + Added message if you clear your pre/post command stacks which was
781 # very easy to do if you just typed a bare >, <, or {. (A command
782 # without an argument should *never* be a destructive action; this
783 # API is fundamentally screwed up; likewise option setting, which
784 # is equally buggered.)
785 # + Added command stack dump on argument of "?" for >, <, or {.
786 # + Added a semi-built-in doc viewer command that calls man with the
787 # proper %Config::Config path (and thus gets caching, man -k, etc),
788 # or else perldoc on obstreperous platforms.
789 # + Added to and rearranged the help information.
790 # + Detected apparent misuse of { ... } to declare a block; this used
791 # to work but now is a command, and mysteriously gave no complaint.
793 # Changes: 1.08: Apr 25, 2001 Jon Eveland <jweveland@yahoo.com>
795 # + This patch to perl5db.pl cleans up formatting issues on the help
796 # summary (h h) screen in the debugger. Mostly columnar alignment
797 # issues, plus converted the printed text to use all spaces, since
798 # tabs don't seem to help much here.
800 # Changes: 1.09: May 19, 2001 Ilya Zakharevich <ilya@math.ohio-state.edu>
801 # Minor bugs corrected;
802 # + Support for auto-creation of new TTY window on startup, either
803 # unconditionally, or if started as a kid of another debugger session;
804 # + New `O'ption CreateTTY
805 # I<CreateTTY> bits control attempts to create a new TTY on events:
807 # 2: debugger is started inside debugger
809 # + Code to auto-create a new TTY window on OS/2 (currently one
810 # extra window per session - need named pipes to have more...);
811 # + Simplified interface for custom createTTY functions (with a backward
812 # compatibility hack); now returns the TTY name to use; return of ''
813 # means that the function reset the I/O handles itself;
814 # + Better message on the semantic of custom createTTY function;
815 # + Convert the existing code to create a TTY into a custom createTTY
817 # + Consistent support for TTY names of the form "TTYin,TTYout";
818 # + Switch line-tracing output too to the created TTY window;
819 # + make `b fork' DWIM with CORE::GLOBAL::fork;
820 # + High-level debugger API cmd_*():
821 # cmd_b_load($filenamepart) # b load filenamepart
822 # cmd_b_line($lineno [, $cond]) # b lineno [cond]
823 # cmd_b_sub($sub [, $cond]) # b sub [cond]
824 # cmd_stop() # Control-C
825 # cmd_d($lineno) # d lineno (B)
826 # The cmd_*() API returns FALSE on failure; in this case it outputs
827 # the error message to the debugging output.
828 # + Low-level debugger API
829 # break_on_load($filename) # b load filename
830 # @files = report_break_on_load() # List files with load-breakpoints
831 # breakable_line_in_filename($name, $from [, $to])
832 # # First breakable line in the
833 # # range $from .. $to. $to defaults
834 # # to $from, and may be less than
836 # breakable_line($from [, $to]) # Same for the current file
837 # break_on_filename_line($name, $lineno [, $cond])
838 # # Set breakpoint,$cond defaults to
840 # break_on_filename_line_range($name, $from, $to [, $cond])
841 # # As above, on the first
842 # # breakable line in range
843 # break_on_line($lineno [, $cond]) # As above, in the current file
844 # break_subroutine($sub [, $cond]) # break on the first breakable line
845 # ($name, $from, $to) = subroutine_filename_lines($sub)
846 # # The range of lines of the text
847 # The low-level API returns TRUE on success, and die()s on failure.
849 # Changes: 1.10: May 23, 2001 Daniel Lewart <d-lewart@uiuc.edu>
851 # + Fixed warnings generated by "perl -dWe 42"
852 # + Corrected spelling errors
853 # + Squeezed Help (h) output into 80 columns
855 # Changes: 1.11: May 24, 2001 David Dyck <dcd@tc.fluke.com>
856 # + Made "x @INC" work like it used to
858 # Changes: 1.12: May 24, 2001 Daniel Lewart <d-lewart@uiuc.edu>
859 # + Fixed warnings generated by "O" (Show debugger options)
860 # + Fixed warnings generated by "p 42" (Print expression)
861 # Changes: 1.13: Jun 19, 2001 Scott.L.Miller@compaq.com
862 # + Added windowSize option
863 # Changes: 1.14: Oct 9, 2001 multiple
864 # + Clean up after itself on VMS (Charles Lane in 12385)
865 # + Adding "@ file" syntax (Peter Scott in 12014)
866 # + Debug reloading selfloaded stuff (Ilya Zakharevich in 11457)
867 # + $^S and other debugger fixes (Ilya Zakharevich in 11120)
868 # + Forgot a my() declaration (Ilya Zakharevich in 11085)
869 # Changes: 1.15: Nov 6, 2001 Michael G Schwern <schwern@pobox.com>
870 # + Updated 1.14 change log
871 # + Added *dbline explainatory comments
872 # + Mentioning perldebguts man page
873 # Changes: 1.16: Feb 15, 2002 Mark-Jason Dominus <mjd@plover.com>
874 # + $onetimeDump improvements
875 # Changes: 1.17: Feb 20, 2002 Richard Foley <richard.foley@rfi.net>
876 # Moved some code to cmd_[.]()'s for clarity and ease of handling,
877 # rationalised the following commands and added cmd_wrapper() to
878 # enable switching between old and frighteningly consistent new
879 # behaviours for diehards: 'o CommandSet=pre580' (sigh...)
880 # a(add), A(del) # action expr (added del by line)
881 # + b(add), B(del) # break [line] (was b,D)
882 # + w(add), W(del) # watch expr (was W,W)
883 # # added del by expr
884 # + h(summary), h h(long) # help (hh) (was h h,h)
885 # + m(methods), M(modules) # ... (was m,v)
886 # + o(option) # lc (was O)
887 # + v(view code), V(view Variables) # ... (was w,V)
888 # Changes: 1.18: Mar 17, 2002 Richard Foley <richard.foley@rfi.net>
889 # + fixed missing cmd_O bug
890 # Changes: 1.19: Mar 29, 2002 Spider Boardman
891 # + Added missing local()s -- DB::DB is called recursively.
892 # Changes: 1.20: Feb 17, 2003 Richard Foley <richard.foley@rfi.net>
893 # + pre'n'post commands no longer trashed with no args
894 # + watch val joined out of eval()
895 # Changes: 1.21: Aug 04, 2002 Joe McMahon (mcmahon@ibiblio.org)
896 # + Added comments and reformatted source. No bug fixes/enhancements.
898 ####################################################################
900 =head1 DEBUGGER INITIALIZATION
902 The debugger starts up in phases.
906 First, it initializes the environment it wants to run in: turning off
907 warnings during its own compilation, defining variables which it will need
908 to avoid warnings later, setting itself up to not exit when the program
909 terminates, and defaulting to printing return values for the C<r> command.
913 # Needed for the statement after exec():
915 # This BEGIN block is simply used to switch off warnings during debugger
916 # compiliation. Probably it would be better practice to fix the warnings,
917 # but this is how it's done at the moment.
922 } # Switch compilation warnings off until another BEGIN.
924 local ($^W) = 0; # Switch run-time warnings off during init.
926 # This would probably be better done with "use vars", but that wasn't around
927 # when this code was originally written. (Neither was "use strict".) And on
928 # the principle of not fiddling with something that was working, this was
931 # These variables control the execution of 'dumpvar.pl'.
933 $dumpvar::arrayDepth,
934 $dumpvar::dumpDBFiles,
935 $dumpvar::dumpPackages,
936 $dumpvar::quoteHighBit,
937 $dumpvar::printUndef,
941 # used to save @ARGV and extract any debugger-related flags.
944 # used to control die() reporting in diesignal()
947 # used to prevent multiple entries to diesignal()
948 # (if for instance diesignal() itself dies)
951 # used to prevent the debugger from running nonstop
957 # Command-line + PERLLIB:
958 # Save the contents of @INC before they are modified elsewhere.
961 # This was an attempt to clear out the previous values of various
962 # trapped errors. Apparently it didn't help. XXX More info needed!
963 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
965 # We set these variables to safe values. We don't want to blindly turn
966 # off warnings, because other packages may still want them.
967 $trace = $signal = $single = 0; # Uninitialized warning suppression
968 # (local $^W cannot help - other packages!).
970 # Default to not exiting when program finishes; print the return
971 # value when the 'r' command is used to return from a subroutine.
972 $inhibit_exit = $option{PrintRet} = 1;
974 =head1 OPTION PROCESSING
976 The debugger's options are actually spread out over the debugger itself and
977 C<dumpvar.pl>; some of these are variables to be set, while others are
978 subs to be called with a value. To try to make this a little easier to
979 manage, the debugger uses a few data structures to define what options
980 are legal and how they are to be processed.
982 First, the C<@options> array defines the I<names> of all the options that
989 hashDepth arrayDepth dumpDepth
990 DumpDBFiles DumpPackages DumpReused
991 compactDump veryCompact quote
992 HighBit undefPrint globPrint
993 PrintRet UsageOnly frame
995 ReadLine NonStop LineInfo
996 maxTraceLen recallCommand ShellBang
997 pager tkRunning ornaments
998 signalLevel warnLevel dieLevel
999 inhibit_exit ImmediateStop bareStringify
1000 CreateTTY RemotePort windowSize
1005 Second, C<optionVars> lists the variables that each option uses to save its
1011 hashDepth => \$dumpvar::hashDepth,
1012 arrayDepth => \$dumpvar::arrayDepth,
1013 CommandSet => \$CommandSet,
1014 DumpDBFiles => \$dumpvar::dumpDBFiles,
1015 DumpPackages => \$dumpvar::dumpPackages,
1016 DumpReused => \$dumpvar::dumpReused,
1017 HighBit => \$dumpvar::quoteHighBit,
1018 undefPrint => \$dumpvar::printUndef,
1019 globPrint => \$dumpvar::globPrint,
1020 UsageOnly => \$dumpvar::usageOnly,
1021 CreateTTY => \$CreateTTY,
1022 bareStringify => \$dumpvar::bareStringify,
1024 AutoTrace => \$trace,
1025 inhibit_exit => \$inhibit_exit,
1026 maxTraceLen => \$maxtrace,
1027 ImmediateStop => \$ImmediateStop,
1028 RemotePort => \$remoteport,
1029 windowSize => \$window,
1034 Third, C<%optionAction> defines the subroutine to be called to process each
1040 compactDump => \&dumpvar::compactDump,
1041 veryCompact => \&dumpvar::veryCompact,
1042 quote => \&dumpvar::quote,
1045 ReadLine => \&ReadLine,
1046 NonStop => \&NonStop,
1047 LineInfo => \&LineInfo,
1048 recallCommand => \&recallCommand,
1049 ShellBang => \&shellBang,
1051 signalLevel => \&signalLevel,
1052 warnLevel => \&warnLevel,
1053 dieLevel => \&dieLevel,
1054 tkRunning => \&tkRunning,
1055 ornaments => \&ornaments,
1056 RemotePort => \&RemotePort,
1061 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1066 # Note that this list is not complete: several options not listed here
1067 # actually require that dumpvar.pl be loaded for them to work, but are
1068 # not in the table. A subsequent patch will correct this problem; for
1069 # the moment, we're just recommenting, and we are NOT going to change
1072 compactDump => 'dumpvar.pl',
1073 veryCompact => 'dumpvar.pl',
1074 quote => 'dumpvar.pl',
1079 There are a number of initialization-related variables which can be set
1080 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1081 variable. These are:
1085 =item C<$rl> - readline control XXX needs more explanation
1087 =item C<$warnLevel> - whether or not debugger takes over warning handling
1089 =item C<$dieLevel> - whether or not debugger takes over die handling
1091 =item C<$signalLevel> - whether or not debugger takes over signal handling
1093 =item C<$pre> - preprompt actions (array reference)
1095 =item C<$post> - postprompt actions (array reference)
1099 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1101 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1105 # These guys may be defined in $ENV{PERL5DB} :
1106 $rl = 1 unless defined $rl;
1107 $warnLevel = 1 unless defined $warnLevel;
1108 $dieLevel = 1 unless defined $dieLevel;
1109 $signalLevel = 1 unless defined $signalLevel;
1110 $pre = [] unless defined $pre;
1111 $post = [] unless defined $post;
1112 $pretype = [] unless defined $pretype;
1113 $CreateTTY = 3 unless defined $CreateTTY;
1114 $CommandSet = '580' unless defined $CommandSet;
1118 The default C<die>, C<warn>, and C<signal> handlers are set up.
1122 warnLevel($warnLevel);
1123 dieLevel($dieLevel);
1124 signalLevel($signalLevel);
1128 The pager to be used is needed next. We try to get it from the enviroment first.
1129 if it's not defined there, we try to find it in the Perl C<Config.pm>.
1130 If it's not there, we default to C<more>. We then call the C<pager()>
1131 fucntion to save the pager name.
1135 # This routine makes sure $pager is set up so that '|' can use it.
1137 # If PAGER is defined in the environment, use it.
1141 # If not, see if Config.pm defines it.
1142 : eval { require Config } && defined $Config::Config{pager}
1143 ? $Config::Config{pager}
1145 # If not, fall back to 'more'.
1148 unless defined $pager;
1152 We set up the command to be used to access the man pages, the command
1153 recall character ("!" unless otherwise defined) and the shell escape
1154 character ("!" unless otherwise defined). Yes, these do conflict, and
1155 neither works in the debugger at the moment.
1161 # Set up defaults for command recall and shell escape (note:
1162 # these currently don't work in linemode debugging).
1163 &recallCommand("!") unless defined $prc;
1164 &shellBang("!") unless defined $psh;
1168 We then set up the gigantic string containing the debugger help.
1169 We also set the limit on the number of arguments we'll display during a
1176 # If we didn't get a default for the length of eval/stack trace args,
1178 $maxtrace = 400 unless defined $maxtrace;
1180 =head2 SETTING UP THE DEBUGGER GREETING
1182 The debugger 'greeting' helps to inform the user how many debuggers are
1183 running, and whether the current debugger is the primary or a child.
1185 If we are the primary, we just hang onto our pid so we'll have it when
1186 or if we start a child debugger. If we are a child, we'll set things up
1187 so we'll have a unique greeting and so the parent will give us our own
1190 We save the current contents of the C<PERLDB_PIDS> environment variable
1191 because we mess around with it. We'll also need to hang onto it because
1192 we'll need it if we restart.
1194 Child debuggers make a label out of the current PID structure recorded in
1195 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1196 yet so the parent will give them one later via C<resetterm()>.
1200 # Save the current contents of the environment; we're about to
1201 # much with it. We'll need this if we have to restart.
1202 $ini_pids = $ENV{PERLDB_PIDS};
1204 if (defined $ENV{PERLDB_PIDS}) {
1205 # We're a child. Make us a label out of the current PID structure
1206 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1207 # a term yet so the parent will give us one later via resetterm().
1208 $pids = "[$ENV{PERLDB_PIDS}]";
1209 $ENV{PERLDB_PIDS} .= "->$$";
1211 } ## end if (defined $ENV{PERLDB_PIDS...
1213 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1214 # child debugger, and mark us as the parent, so we'll know to set up
1215 # more TTY's is we have to.
1216 $ENV{PERLDB_PIDS} = "$$";
1223 # Sets up $emacs as a synonym for $slave_editor.
1224 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1226 =head2 READING THE RC FILE
1228 The debugger will read a file of initialization options if supplied. If
1229 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1233 # As noted, this test really doesn't check accurately that the debugger
1234 # is running at a terminal or not.
1235 if (-e "/dev/tty") { # this is the wrong metric!
1236 $rcfile = ".perldb";
1239 $rcfile = "perldb.ini";
1244 The debugger does a safety test of the file to be read. It must be owned
1245 either by the current user or root, and must only be writable by the owner.
1249 # This wraps a safety test around "do" to read and evaluate the init file.
1251 # This isn't really safe, because there's a race
1252 # between checking and opening. The solution is to
1253 # open and fstat the handle, but then you have to read and
1254 # eval the contents. But then the silly thing gets
1255 # your lexical scope, which is unfortunate at best.
1259 # Just exactly what part of the word "CORE::" don't you understand?
1260 local $SIG{__WARN__};
1261 local $SIG{__DIE__};
1263 unless (is_safe_file($file)) {
1264 CORE::warn <<EO_GRIPE;
1265 perldb: Must not source insecure rcfile $file.
1266 You or the superuser must be the owner, and it must not
1267 be writable by anyone but its owner.
1270 } ## end unless (is_safe_file($file...
1273 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1274 } ## end sub safe_do
1276 # This is the safety test itself.
1278 # Verifies that owner is either real user or superuser and that no
1279 # one but owner may write to it. This function is of limited use
1280 # when called on a path instead of upon a handle, because there are
1281 # no guarantees that filename (by dirent) whose file (by ino) is
1282 # eventually accessed is the same as the one tested.
1283 # Assumes that the file's existence is not in doubt.
1286 stat($path) || return; # mysteriously vaporized
1287 my ($dev, $ino, $mode, $nlink, $uid, $gid) = stat(_);
1289 return 0 if $uid != 0 && $uid != $<;
1290 return 0 if $mode & 022;
1292 } ## end sub is_safe_file
1294 # If the rcfile (whichever one we decided was the right one to read)
1295 # exists, we safely do it.
1297 safe_do("./$rcfile");
1299 # If there isn't one here, try the user's home directory.
1300 elsif (defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile") {
1301 safe_do("$ENV{HOME}/$rcfile");
1303 # Else try the login directory.
1304 elsif (defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile") {
1305 safe_do("$ENV{LOGDIR}/$rcfile");
1308 # If the PERLDB_OPTS variable has options in it, parse those out next.
1309 if (defined $ENV{PERLDB_OPTS}) {
1310 parse_options($ENV{PERLDB_OPTS});
1315 The last thing we do during initialization is determine which subroutine is
1316 to be used to obtain a new terminal when a new debugger is started. Right now,
1317 the debugger only handles X Windows and OS/2.
1321 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1322 # Works if you're running an xterm or xterm-like window, or you're on
1323 # OS/2. This may need some expansion: for instance, this doesn't handle
1324 # OS X Terminal windows.
1326 if (not defined &get_fork_TTY # no routine exists,
1327 and defined $ENV{TERM} # and we know what kind
1328 # of terminal this is,
1329 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1330 and defined $ENV{WINDOWID} # and we know what
1332 and defined $ENV{DISPLAY}) # and what display it's
1335 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1336 } ## end if (not defined &get_fork_TTY...
1337 elsif ($^O eq 'os2') { # If this is OS/2,
1338 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1341 # "Here begin the unreadable code. It needs fixing."
1343 =head2 RESTART PROCESSING
1345 This section handles the restart command. When the C<R> command is invoked, it
1346 tries to capture all of the state it can into environment variables, and
1347 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1348 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1349 the R command stuffed into the environment variables.
1351 PERLDB_RESTART - flag only, contains no restart data itself.
1352 PERLDB_HIST - command history, if it's available
1353 PERLDB_ON_LOAD - breakpoints set by the rc file
1354 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1355 PERLDB_VISITED - files that had breakpoints
1356 PERLDB_FILE_... - breakpoints for a file
1357 PERLDB_OPT - active options
1358 PERLDB_INC - the original @INC
1359 PERLDB_PRETYPE - preprompt debugger actions
1360 PERLDB_PRE - preprompt Perl code
1361 PERLDB_POST - post-prompt Perl code
1362 PERLDB_TYPEAHEAD - typeahead captured by readline()
1364 We chug through all these variables and plug the values saved in them
1365 back into the appropriate spots in the debugger.
1369 if (exists $ENV{PERLDB_RESTART}) {
1370 # We're restarting, so we don't need the flag that says to restart anymore.
1371 delete $ENV{PERLDB_RESTART};
1373 @hist = get_list('PERLDB_HIST');
1374 %break_on_load = get_list("PERLDB_ON_LOAD");
1375 %postponed = get_list("PERLDB_POSTPONE");
1377 # restore breakpoints/actions
1378 my @had_breakpoints = get_list("PERLDB_VISITED");
1379 for (0 .. $#had_breakpoints) {
1380 my %pf = get_list("PERLDB_FILE_$_");
1381 $postponed_file{ $had_breakpoints[$_] } = \%pf if %pf;
1385 my %opt = get_list("PERLDB_OPT");
1387 while (($opt, $val) = each %opt) {
1388 $val =~ s/[\\\']/\\$1/g;
1389 parse_options("$opt'$val'");
1392 # restore original @INC
1393 @INC = get_list("PERLDB_INC");
1396 # return pre/postprompt actions and typeahead buffer
1397 $pretype = [get_list("PERLDB_PRETYPE")];
1398 $pre = [get_list("PERLDB_PRE")];
1399 $post = [get_list("PERLDB_POST")];
1400 @typeahead = get_list("PERLDB_TYPEAHEAD", @typeahead);
1401 } ## end if (exists $ENV{PERLDB_RESTART...
1403 =head2 SETTING UP THE TERMINAL
1405 Now, we'll decide how the debugger is going to interact with the user.
1406 If there's no TTY, we set the debugger to run non-stop; there's not going
1407 to be anyone there to enter commands.
1417 If there is a TTY, we have to determine who it belongs to before we can
1418 proceed. If this is a slave editor or graphical debugger (denoted by
1419 the first command-line switch being '-emacs'), we shift this off and
1420 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1425 # Is Perl being run from a slave editor or graphical debugger?
1426 # If so, don't use readline, and set $slave_editor = 1.
1428 ((defined $main::ARGV[0]) and ($main::ARGV[0] eq '-emacs'));
1429 $rl = 0, shift (@main::ARGV) if $slave_editor;
1430 #require Term::ReadLine;
1434 We then determine what the console should be on various systems:
1438 =item * Cygwin - We use C<stdin> instead of a separate device.
1443 if ($^O eq 'cygwin') {
1444 # /dev/tty is binary. use stdin for textmode
1448 =item * Unix - use C</dev/tty>.
1452 elsif (-e "/dev/tty") {
1453 $console = "/dev/tty";
1456 =item * Windows or MSDOS - use C<con>.
1460 elsif ($^O eq 'dos' or -e "con" or $^O eq 'MSWin32') {
1464 =item * MacOS - use C<Dev:Console:Perl Debug> if this is the MPW version; C<Dev:
1465 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.)
1469 elsif ($^O eq 'MacOS') {
1470 if ($MacPerl::Version !~ /MPW/) {
1472 "Dev:Console:Perl Debug"; # Separate window for application
1475 $console = "Dev:Console";
1477 } ## end elsif ($^O eq 'MacOS')
1479 =item * VMS - use C<sys$command>.
1484 # everything else is ...
1485 $console = "sys\$command";
1492 Several other systems don't use a specific console. We C<undef $console>
1493 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1494 with a slave editor, Epoc).
1498 if (($^O eq 'MSWin32') and ($slave_editor or defined $ENV{EMACS})) {
1499 # /dev/tty is binary. use stdin for textmode
1503 if ($^O eq 'NetWare') {
1504 # /dev/tty is binary. use stdin for textmode
1508 # In OS/2, we need to use STDIN to get textmode too, even though
1509 # it pretty much looks like Unix otherwise.
1510 if (defined $ENV{OS2_SHELL} and ($slave_editor or $ENV{WINDOWID}))
1514 # EPOC also falls into the 'got to use STDIN' camp.
1515 if ($^O eq 'epoc') {
1521 If there is a TTY hanging around from a parent, we use that as the console.
1525 $console = $tty if defined $tty;
1527 =head2 SOCKET HANDLING
1529 The debugger is capable of opening a socket and carrying out a debugging
1530 session over the socket.
1532 If C<RemotePort> was defined in the options, the debugger assumes that it
1533 should try to start a debugging session on that port. It builds the socket
1534 and then tries to connect the input and output filehandles to it.
1538 # Handle socket stuff.
1539 if (defined $remoteport) {
1540 # If RemotePort was defined in the options, connect input and output
1543 $OUT = new IO::Socket::INET(
1545 PeerAddr => $remoteport,
1548 if (!$OUT) { die "Unable to connect to remote host: $remoteport\n"; }
1550 } ## end if (defined $remoteport)
1554 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1555 this is probably a situation where multiple debuggers are running (for example,
1556 a backticked command that starts up another debugger). We create a new IN and
1557 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1564 # Two debuggers running (probably a system or a backtick that invokes
1565 # the debugger itself under the running one). create a new IN and OUT
1566 # filehandle, and do the necessary mojo to create a new tty if we
1567 # know how, and we can.
1568 create_IN_OUT(4) if $CreateTTY & 4;
1570 # If we have a console, check to see if there are separate ins and
1571 # outs to open. (They are assumed identiical if not.)
1572 my ($i, $o) = split /,/, $console;
1573 $o = $i unless defined $o;
1575 # read/write on in, or just read, or read on STDIN.
1578 open(IN, "<&STDIN");
1580 # read/write/create/clobber out, or write/create/clobber out,
1581 # or merge with STDERR, or merge with STDOUT.
1582 open(OUT, "+>$o") ||
1584 open(OUT, ">&STDERR") ||
1585 open(OUT, ">&STDOUT"); # so we don't dongle stdout
1587 } ## end if ($console)
1588 elsif (not defined $console) {
1589 # No console. Open STDIN.
1590 open(IN, "<&STDIN");
1592 # merge with STDERR, or with STDOUT.
1593 open(OUT, ">&STDERR") ||
1594 open(OUT, ">&STDOUT"); # so we don't dongle stdout
1596 $console = 'STDIN/OUT';
1597 } ## end elsif (not defined $console)
1599 # Keep copies of the filehandles so that when the pager runs, it
1600 # can close standard input without clobbering ours.
1601 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1602 } ## end elsif (from if(defined $remoteport))
1604 # Unbuffer DB::OUT. We need to see responses right away.
1605 my $previous = select($OUT);
1606 $| = 1; # for DB::OUT
1609 # Line info goes to debugger output unless pointed elsewhere.
1610 # Pointing elsewhere makes it possible for slave editors to
1611 # keep track of file and position. We have both a filehandle
1612 # and a I/O description to keep track of.
1613 $LINEINFO = $OUT unless defined $LINEINFO;
1614 $lineinfo = $console unless defined $lineinfo;
1618 To finish initialization, we show the debugger greeting,
1619 and then call the C<afterinit()> subroutine if there is one.
1623 # Show the debugger greeting.
1624 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1625 unless ($runnonstop) {
1628 if ($term_pid eq '-1') {
1629 print $OUT "\nDaughter DB session started...\n";
1632 print $OUT "\nLoading DB routines from $header\n";
1635 $slave_editor ? "enabled" : "available", ".\n"
1638 "\nEnter h or `h h' for help, or `$doccmd perldebug' for more help.\n\n";
1639 } ## end else [ if ($term_pid eq '-1')
1640 } ## end unless ($runnonstop)
1641 } ## end else [ if ($notty)
1643 # XXX This looks like a bug to me.
1644 # Why copy to @ARGS and then futz with @args?
1647 # Make sure backslashes before single quotes are stripped out, and
1648 # keep args unless they are numeric (XXX why?)
1650 s/(.*)/'$1'/ unless /^-?[\d.]+$/;
1653 # If there was an afterinit() sub defined, call it. It will get
1654 # executed in our scope, so it can fiddle with debugger globals.
1655 if (defined &afterinit) { # May be defined in $rcfile
1658 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1661 ############################################################ Subroutines
1667 This gigantic subroutine is the heart of the debugger. Called before every
1668 statement, its job is to determine if a breakpoint has been reached, and
1669 stop if so; read commands from the user, parse them, and execute
1670 them, and hen send execution off to the next statement.
1672 Note that the order in which the commands are processed is very important;
1673 some commands earlier in the loop will actually alter the C<$cmd> variable
1674 to create other commands to be executed later. This is all highly "optimized"
1675 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1676 see what's happening in any given command.
1682 # Check for whether we should be running continuously or not.
1683 # _After_ the perl program is compiled, $single is set to 1:
1684 if ($single and not $second_time++) {
1685 # Options say run non-stop. Run until we get an interrupt.
1686 if ($runnonstop) { # Disable until signal
1687 # If there's any call stack in place, turn off single
1688 # stepping into subs throughout the stack.
1689 for ($i = 0 ; $i <= $stack_depth ;) {
1692 # And we are now no longer in single-step mode.
1695 # If we simply returned at this point, we wouldn't get
1696 # the trace info. Fall on through.
1698 } ## end if ($runnonstop)
1700 elsif ($ImmediateStop) {
1701 # We are supposed to stop here; XXX probably a break.
1702 $ImmediateStop = 0; # We've processed it; turn it off
1703 $signal = 1; # Simulate an interrupt to force
1704 # us into the command loop
1706 } ## end if ($single and not $second_time...
1708 # If we're in single-step mode, or an interrupt (real or fake)
1709 # has occurred, turn off non-stop mode.
1710 $runnonstop = 0 if $single or $signal;
1712 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1713 # The code being debugged may have altered them.
1716 # Since DB::DB gets called after every line, we can use caller() to
1717 # figure out where we last were executing. Sneaky, eh? This works because
1718 # caller is returning all the extra information when called from the
1720 local ($package, $filename, $line) = caller;
1721 local $filename_ini = $filename;
1723 # set up the context for DB::eval, so it can properly execute
1724 # code on behalf of the user. We add the package in so that the
1725 # code is eval'ed in the proper package (not in the debugger!).
1726 local $usercontext =
1727 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' .
1728 "package $package;";
1730 # Create an alias to the active file magical array to simplify
1732 local (*dbline) = $main::{ '_<' . $filename };
1734 # we need to check for pseudofiles on Mac OS (these are files
1735 # not attached to a filename, but instead stored in Dev:Pseudo)
1736 if ($^O eq 'MacOS' && $#dbline < 0) {
1737 $filename_ini = $filename = 'Dev:Pseudo';
1738 *dbline = $main::{ '_<' . $filename };
1741 # Last line in the program.
1742 local $max = $#dbline;
1744 # if we have something here, see if we should break.
1745 if ($dbline{$line} && (($stop, $action) = split (/\0/, $dbline{$line}))) {
1746 # Stop if the stop criterion says to just stop.
1750 # It's a conditional stop; eval it in the user's context and
1751 # see if we should stop. If so, remove the one-time sigil.
1753 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1755 $dbline{$line} =~ s/;9($|\0)/$1/;
1757 } ## end if ($dbline{$line} && ...
1759 # Preserve the current stop-or-not, and see if any of the W
1760 # (watch expressions) has changed.
1761 my $was_signal = $signal;
1763 # If we have any watch expressions ...
1765 for (my $n = 0 ; $n <= $#to_watch ; $n++) {
1766 $evalarg = $to_watch[$n];
1767 local $onetimeDump; # Tell DB::eval() to not output results
1769 # Fix context DB::eval() wants to return an array, but
1770 # we need a scalar here.
1772 join ( "', '", &eval );
1773 $val = ((defined $val) ? "'$val'" : 'undef');
1776 if ($val ne $old_watch[$n]) {
1777 # Yep! Show the difference, and fake an interrupt.
1780 Watchpoint $n:\t$to_watch[$n] changed:
1781 old value:\t$old_watch[$n]
1784 $old_watch[$n] = $val;
1785 } ## end if ($val ne $old_watch...
1786 } ## end for (my $n = 0 ; $n <= ...
1787 } ## end if ($trace & 2)
1789 =head2 C<watchfunction()>
1791 C<watchfunction()> is a function that can be defined by the user; it is a
1792 function which will be run on each entry to C<DB::DB>; it gets the
1793 current package, filename, and line as its parameters.
1795 The watchfunction can do anything it likes; it is executing in the
1796 debugger's context, so it has access to all of the debugger's internal
1797 data structures and functions.
1799 C<watchfunction()> can control the debugger's actions. Any of the following
1800 will cause the debugger to return control to the user's program after
1801 C<watchfunction()> executes:
1805 =item * Returning a false value from the C<watchfunction()> itself.
1807 =item * Altering C<$single> to a false value.
1809 =item * Altering C<$signal> to a false value.
1811 =item * Turning off the '4' bit in C<$trace> (this also disables the
1812 check for C<watchfunction()>. This can be done with
1820 # If there's a user-defined DB::watchfunction, call it with the
1821 # current package, filename, and line. The function executes in
1823 if ($trace & 4) { # User-installed watch
1825 if watchfunction($package, $filename, $line)
1828 and not($trace & ~4);
1829 } ## end if ($trace & 4)
1832 # Pick up any alteration to $signal in the watchfunction, and
1833 # turn off the signal now.
1834 $was_signal = $signal;
1837 =head2 GETTING READY TO EXECUTE COMMANDS
1839 The debugger decides to take control if single-step mode is on, the
1840 C<t> command was entered, or the user generated a signal. If the program
1841 has fallen off the end, we set things up so that entering further commands
1842 won't cause trouble, and we say that the program is over.
1846 # Check to see if we should grab control ($single true,
1847 # trace set appropriately, or we got a signal).
1848 if ($single || ($trace & 1) || $was_signal) {
1849 # Yes, grab control.
1850 if ($slave_editor) {
1851 # Tell the editor to update its position.
1852 $position = "\032\032$filename:$line:0\n";
1853 print_lineinfo($position);
1858 Special check: if we're in package C<DB::fake>, we've gone through the
1859 C<END> block at least once. We set up everything so that we can continue
1860 to enter commands and have a valid context to be in.
1864 elsif ($package eq 'DB::fake') {
1865 # Fallen off the end already.
1868 Debugged program terminated. Use B<q> to quit or B<R> to restart,
1869 use B<O> I<inhibit_exit> to avoid stopping after program termination,
1870 B<h q>, B<h R> or B<h O> to get additional info.
1873 # Set the DB::eval context appropriately.
1876 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' .
1877 "package $package;"; # this won't let them modify, alas
1878 } ## end elsif ($package eq 'DB::fake')
1882 If the program hasn't finished executing, we scan forward to the
1883 next executable line, print that out, build the prompt from the file and line
1884 number information, and print that.
1889 # Still somewhere in the midst of execution. Set up the
1891 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
1892 # Perl 5 ones (sorry, we don't print Klingon
1895 $prefix = $sub =~ /::/ ? "" : "${'package'}::";
1896 $prefix .= "$sub($filename:";
1897 $after = ($dbline[$line] =~ /\n$/ ? '' : "\n");
1899 # Break up the prompt if it's really long.
1900 if (length($prefix) > 30) {
1901 $position = "$prefix$line):\n$line:\t$dbline[$line]$after";
1907 $position = "$prefix$line$infix$dbline[$line]$after";
1910 # Print current line info, indenting if necessary.
1912 print_lineinfo(' ' x $stack_depth,
1913 "$line:\t$dbline[$line]$after");
1916 print_lineinfo($position);
1919 # Scan forward, stopping at either the end or the next
1921 for ($i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i)
1924 # Drop out on null statements, block closers, and comments.
1925 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/;
1927 # Drop out if the user interrupted us.
1930 # Append a newline if the line doesn't have one. Can happen
1931 # in eval'ed text, for instance.
1932 $after = ($dbline[$i] =~ /\n$/ ? '' : "\n");
1934 # Next executable line.
1935 $incr_pos = "$prefix$i$infix$dbline[$i]$after";
1936 $position .= $incr_pos;
1938 # Print it indented if tracing is on.
1939 print_lineinfo(' ' x $stack_depth,
1940 "$i:\t$dbline[$i]$after");
1943 print_lineinfo($incr_pos);
1945 } ## end for ($i = $line + 1 ; $i...
1946 } ## end else [ if ($slave_editor)
1947 } ## end if ($single || ($trace...
1951 If there's an action to be executed for the line we stopped at, execute it.
1952 If there are any preprompt actions, execute those as well.
1956 # If there's an action, do it now.
1957 $evalarg = $action, &eval if $action;
1959 # Are we nested another level (e.g., did we evaluate a function
1960 # that had a breakpoint in it at the debugger prompt)?
1961 if ($single || $was_signal) {
1962 # Yes, go down a level.
1963 local $level = $level + 1;
1965 # Do any pre-prompt actions.
1966 foreach $evalarg (@$pre) {
1970 # Complain about too much recursion if we passed the limit.
1971 print $OUT $stack_depth . " levels deep in subroutine calls!\n"
1974 # The line we're currently on. Set $incr to -1 to stay here
1975 # until we get a command that tells us to advance.
1977 $incr = -1; # for backward motion.
1979 # Tack preprompt debugger actions ahead of any actual input.
1980 @typeahead = (@$pretype, @typeahead);
1982 =head2 WHERE ARE WE?
1984 XXX Relocate this section?
1986 The debugger normally shows the line corresponding to the current line of
1987 execution. Sometimes, though, we want to see the next line, or to move elsewhere
1988 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
1990 C<$incr> controls by how many lines the "current" line should move forward
1991 after a command is executed. If set to -1, this indicates that the "current"
1992 line shouldn't change.
1994 C<$start> is the "current" line. It is used for things like knowing where to
1995 move forwards or backwards from when doing an C<L> or C<-> command.
1997 C<$max> tells the debugger where the last line of the current file is. It's
1998 used to terminate loops most often.
2000 =head2 THE COMMAND LOOP
2002 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2007 =item * The outer part of the loop, starting at the C<CMD> label. This loop
2008 reads a command and then executes it.
2010 =item * The inner part of the loop, starting at the C<PIPE> label. This part
2011 is wholly contained inside the C<CMD> block and only executes a command.
2012 Used to handle commands running inside a pager.
2016 So why have two labels to restart the loop? Because sometimes, it's easier to
2017 have a command I<generate> another command and then re-execute the loop to do
2018 the new command. This is faster, but perhaps a bit more convoluted.
2022 # The big command dispatch loop. It keeps running until the
2023 # user yields up control again.
2025 # If we have a terminal for input, and we get something back
2026 # from readline(), keep on processing.
2029 # We have a terminal, or can get one ...
2030 ($term || &setterm),
2031 # ... and it belogs to this PID or we get one for this PID ...
2032 ($term_pid == $$ or resetterm(1)),
2033 # ... and we got a line of command input ...
2036 "$pidprompt DB" . ('<' x $level) . ($#hist + 1) .
2037 ('>' x $level) . " "
2042 # ... try to execute the input as debugger commands.
2044 # Don't stop running.
2047 # No signal is active.
2050 # Handle continued commands (ending with \):
2051 $cmd =~ s/\\$/\n/ && do {
2052 $cmd .= &readline(" cont: ");
2056 =head4 The null command
2058 A newline entered by itself means "re-execute the last command". We grab the
2059 command out of C<$laststep> (where it was recorded previously), and copy it
2060 back into C<$cmd> to be executed below. If there wasn't any previous command,
2061 we'll do nothing below (no command will match). If there was, we also save it
2062 in the command history and fall through to allow the command parsing to pick
2067 # Empty input means repeat the last command.
2068 $cmd =~ /^$/ && ($cmd = $laststep);
2069 push (@hist, $cmd) if length($cmd) > 1;
2072 # This is a restart point for commands that didn't arrive
2073 # via direct user input. It allows us to 'redo PIPE' to
2074 # re-execute command processing without reading a new command.
2076 $cmd =~ s/^\s+//s; # trim annoying leading whitespace
2077 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace
2078 ($i) = split (/\s+/, $cmd);
2080 =head3 COMMAND ALIASES
2082 The debugger can create aliases for commands (these are stored in the
2083 C<%alias> hash). Before a command is executed, the command loop looks it up
2084 in the alias hash and substitutes the contents of the alias for the command,
2085 completely replacing it.
2089 # See if there's an alias for the command, and set it up if so.
2091 # Squelch signal handling; we want to keep control here
2092 # if something goes loco during the alias eval.
2093 local $SIG{__DIE__};
2094 local $SIG{__WARN__};
2096 # This is a command, so we eval it in the DEBUGGER's
2097 # scope! Otherwise, we can't see the special debugger
2098 # variables, or get to the debugger's subs. (Well, we
2099 # _could_, but why make it even more complicated?)
2100 eval "\$cmd =~ $alias{$i}";
2103 print $OUT "Couldn't evaluate `$i' alias: $@";
2106 } ## end if ($alias{$i})
2108 =head3 MAIN-LINE COMMANDS
2110 All of these commands work up to and after the program being debugged has
2115 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2116 try to execute further, cleaning any restart-related stuff out of the
2117 environment, and executing with the last value of C<$?>.
2121 $cmd =~ /^q$/ && do {
2128 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2132 $cmd =~ /^t$/ && do {
2135 print $OUT "Trace = " . (($trace & 1) ? "on" : "off") .
2140 =head4 C<S> - list subroutines matching/not matching a pattern
2142 Walks through C<%sub>, checking to see whether or not to print the name.
2146 $cmd =~ /^S(\s+(!)?(.+))?$/ && do {
2148 $Srev = defined $2; # Reverse scan?
2149 $Spatt = $3; # The pattern (if any) to use.
2150 $Snocheck = !defined $1; # No args - print all subs.
2152 # Need to make these sane here.
2156 # Search through the debugger's magical hash of subs.
2157 # If $nocheck is true, just print the sub name.
2158 # Otherwise, check it against the pattern. We then use
2159 # the XOR trick to reverse the condition as required.
2160 foreach $subname (sort(keys %sub)) {
2161 if ($Snocheck or $Srev ^ ($subname =~ /$Spatt/)) {
2162 print $OUT $subname, "\n";
2168 =head4 C<X> - list variables in current package
2170 Since the C<V> command actually processes this, just change this to the
2171 appropriate C<V> command and fall through.
2175 $cmd =~ s/^X\b/V $package/;
2177 =head4 C<V> - list variables
2179 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2183 # Bare V commands get the currently-being-debugged package
2185 $cmd =~ /^V$/ && do {
2186 $cmd = "V $package";
2190 # V - show variables in package.
2191 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
2192 # Save the currently selected filehandle and
2193 # force output to debugger's filehandle (dumpvar
2194 # just does "print" for output).
2195 local ($savout) = select($OUT);
2197 # Grab package name and variables to dump.
2199 @vars = split (' ', $2);
2201 # If main::dumpvar isn't here, get it.
2202 do 'dumpvar.pl' unless defined &main::dumpvar;
2203 if (defined &main::dumpvar) {
2204 # We got it. Turn off subroutine entry/exit messages
2205 # for the moment. XXX Why do this to doret?
2209 # must detect sigpipe failures - not catching
2210 # then will cause the debugger to die.
2214 defined $option{dumpDepth}
2215 ? $option{dumpDepth}
2216 : -1, # assume -1 unless specified
2221 # The die doesn't need to include the $@, because
2222 # it will automatically get propagated for us.
2224 die unless $@ =~ /dumpvar print failed/;
2226 } ## end if (defined &main::dumpvar)
2228 # Couldn't load dumpvar.
2229 print $OUT "dumpvar.pl not available.\n";
2231 # Restore the output filehandle, and go round again.
2236 =head4 C<x> - evaluate and print an expression
2238 Hands the expression off to C<DB::eval>, setting it up to print the value
2239 via C<dumpvar.pl> instead of just printing it directly.
2243 $cmd =~ s/^x\b/ / && do { # Remainder gets done by DB::eval()
2244 $onetimeDump = 'dump'; # main::dumpvar shows the output
2246 # handle special "x 3 blah" syntax XXX propagate
2247 # doc back to special variables.
2248 if ($cmd =~ s/^\s*(\d+)(?=\s)/ /) {
2249 $onetimedumpDepth = $1;
2253 =head4 C<m> - print methods
2255 Just uses C<DB::methods> to determine what methods are available.
2259 $cmd =~ s/^m\s+([\w:]+)\s*$/ / && do {
2264 # m expr - set up DB::eval to do the work
2265 $cmd =~ s/^m\b/ / && do { # Rest gets done by DB::eval()
2266 $onetimeDump = 'methods'; # method output gets used there
2269 =head4 C<f> - switch files
2273 $cmd =~ /^f\b\s*(.*)/ && do {
2277 # help for no arguments (old-style was return from sub).
2280 "The old f command is now the r command.\n"; # hint
2281 print $OUT "The new f command switches filenames.\n";
2283 } ## end if (!$file)
2285 # if not in magic file list, try a close match.
2286 if (!defined $main::{ '_<' . $file }) {
2287 if (($try) = grep(m#^_<.*$file#, keys %main::)) {
2289 $try = substr($try, 2);
2291 "Choosing $try matching `$file':\n";
2294 } ## end if (($try) = grep(m#^_<.*$file#...
2295 } ## end if (!defined $main::{ ...
2297 # If not successfully switched now, we failed.
2298 if (!defined $main::{ '_<' . $file }) {
2299 print $OUT "No file matching `$file' is loaded.\n";
2303 # We switched, so switch the debugger internals around.
2304 elsif ($file ne $filename) {
2305 *dbline = $main::{ '_<' . $file };
2310 } ## end elsif ($file ne $filename)
2312 # We didn't switch; say we didn't.
2314 print $OUT "Already in $file.\n";
2319 =head4 C<.> - return to last-executed line.
2321 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2322 and then we look up the line in the magical C<%dbline> hash.
2327 $cmd =~ /^\.$/ && do {
2328 $incr = -1; # stay at current line
2330 # Reset everything to the old location.
2332 $filename = $filename_ini;
2333 *dbline = $main::{ '_<' . $filename };
2337 print_lineinfo($position);
2341 =head4 C<-> - back one window
2343 We change C<$start> to be one window back; if we go back past the first line,
2344 we set it to be the first line. We ser C<$incr> to put us back at the
2345 currently-executing line, and then put a C<l $start +> (list one window from
2346 C<$start>) in C<$cmd> to be executed later.
2350 # - - back a window.
2351 $cmd =~ /^-$/ && do {
2352 # back up by a window; go to 1 if back too far.
2353 $start -= $incr + $window + 1;
2354 $start = 1 if $start <= 0;
2355 $incr = $window - 1;
2357 # Generate and execute a "l +" command (handled below).
2358 $cmd = 'l ' . ($start) . '+';
2361 =head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v,
2362 w, W, E<lt>, E<lt>E<lt>, {, {{>
2364 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2365 problems, most notably that the default case of several commands destroying
2366 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2367 retain the old commands for those who were used to using them or who preferred
2368 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2369 deal with them instead of processing them in-line.
2373 # All of these commands were remapped in perl 5.8.0;
2374 # we send them off to the secondary dispatcher (see below).
2375 $cmd =~ /^([aAbBhlLMoOvwW]\b|[<>\{]{1,2})\s*(.*)/so && do {
2376 &cmd_wrapper($1, $2, $line);
2380 =head4 C<y> - List lexicals in higher scope
2382 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2383 above the current one and then displays then using C<dumpvar.pl>.
2387 $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/ && do {
2389 # See if we've got the necessary support.
2390 eval { require PadWalker; PadWalker->VERSION(0.08) }
2393 ? "PadWalker module not found - please install\n"
2398 # Load up dumpvar if we don't have it. If we can, that is.
2399 do 'dumpvar.pl' unless defined &main::dumpvar;
2400 defined &main::dumpvar
2401 or print $OUT "dumpvar.pl not available.\n"
2404 # Got all the modules we need. Find them and print them.
2405 my @vars = split (' ', $2 || '');
2408 my $h = eval { PadWalker::peek_my(($1 || 0) + 1) };
2410 # Oops. Can't find it.
2411 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2413 # Show the desired vars with dumplex().
2414 my $savout = select($OUT);
2416 # Have dumplex dump the lexicals.
2420 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
2422 ) for sort keys %$h;
2427 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2429 All of the commands below this point don't work after the program being
2430 debugged has ended. All of them check to see if the program has ended; this
2431 allows the commands to be relocated without worrying about a 'line of
2432 demarcation' above which commands can be entered anytime, and below which
2435 =head4 C<n> - single step, but don't trace down into subs
2437 Done by setting C<$single> to 2, which forces subs to execute straight through
2438 when entered (see X<DB::sub>). We also save the C<n> command in C<$laststep>,
2439 so a null command knows what to re-execute.
2444 $cmd =~ /^n$/ && do {
2445 end_report(), next CMD if $finished and $level <= 1;
2446 # Single step, but don't enter subs.
2448 # Save for empty command (repeat last).
2453 =head4 C<s> - single-step, entering subs
2455 Sets C<$single> to 1, which causes X<DB::sub> to continue tracing inside
2456 subs. Also saves C<s> as C<$lastcmd>.
2461 $cmd =~ /^s$/ && do {
2462 # Get out and restart the command loop if program
2464 end_report(), next CMD if $finished and $level <= 1;
2465 # Single step should enter subs.
2467 # Save for empty command (repeat last).
2472 =head4 C<c> - run continuously, setting an optional breakpoint
2474 Most of the code for this command is taken up with locating the optional
2475 breakpoint, which is either a subroutine name or a line number. We set
2476 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2477 in this and all call levels above this one.
2481 # c - start continuous execution.
2482 $cmd =~ /^c\b\s*([\w:]*)\s*$/ && do {
2483 # Hey, show's over. The debugged program finished
2484 # executing already.
2485 end_report(), next CMD if $finished and $level <= 1;
2487 # Capture the place to put a one-time break.
2490 # Probably not needed, since we finish an interactive
2491 # sub-session anyway...
2492 # local $filename = $filename;
2493 # local *dbline = *dbline; # XXX Would this work?!
2495 # The above question wonders if localizing the alias
2496 # to the magic array works or not. Since it's commented
2497 # out, we'll just leave that to speculation for now.
2499 # If the "subname" isn't all digits, we'll assume it
2500 # is a subroutine name, and try to find it.
2501 if ($subname =~ /\D/) { # subroutine name
2502 # Qualify it to the current package unless it's
2503 # already qualified.
2504 $subname = $package . "::" . $subname
2505 unless $subname =~ /::/;
2506 # find_sub will return "file:line_number" corresponding
2507 # to where the subroutine is defined; we call find_sub,
2508 # break up the return value, and assign it in one
2510 ($file, $i) = (find_sub($subname) =~ /^(.*):(.*)$/);
2512 # Force the line number to be numeric.
2515 # If we got a line number, we found the sub.
2517 # Switch all the debugger's internals around so
2518 # we're actually working with that file.
2520 *dbline = $main::{ '_<' . $filename };
2521 # Mark that there's a breakpoint in this file.
2522 $had_breakpoints{$filename} |= 1;
2523 # Scan forward to the first executable line
2524 # after the 'sub whatever' line.
2526 ++$i while $dbline[$i] == 0 && $i < $max;
2529 # We didn't find a sub by that name.
2531 print $OUT "Subroutine $subname not found.\n";
2534 } ## end if ($subname =~ /\D/)
2536 # At this point, either the subname was all digits (an
2537 # absolute line-break request) or we've scanned through
2538 # the code following the definition of the sub, looking
2539 # for an executable, which we may or may not have found.
2541 # If $i (which we set $subname from) is non-zero, we
2542 # got a request to break at some line somewhere. On
2543 # one hand, if there wasn't any real subroutine name
2544 # involved, this will be a request to break in the current
2545 # file at the specified line, so we have to check to make
2546 # sure that the line specified really is breakable.
2548 # On the other hand, if there was a subname supplied, the
2549 # preceeding block has moved us to the proper file and
2550 # location within that file, and then scanned forward
2551 # looking for the next executable line. We have to make
2552 # sure that one was found.
2554 # On the gripping hand, we can't do anything unless the
2555 # current value of $i points to a valid breakable line.
2559 if ($dbline[$i] == 0) {
2560 print $OUT "Line $i not breakable.\n";
2563 # Yes. Set up the one-time-break sigil.
2565 s/($|\0)/;9$1/; # add one-time-only b.p.
2568 # Turn off stack tracing from here up.
2569 for ($i = 0 ; $i <= $stack_depth ;) {
2575 =head4 C<r> - return from a subroutine
2577 For C<r> to work properly, the debugger has to stop execution again
2578 immediately after the return is executed. This is done by forcing
2579 single-stepping to be on in the call level above the current one. If
2580 we are printing return values when a C<r> is executed, set C<$doret>
2581 appropriately, and force us out of the command loop.
2585 # r - return from the current subroutine.
2586 $cmd =~ /^r$/ && do {
2587 # Can't do anythign if the program's over.
2588 end_report(), next CMD if $finished and $level <= 1;
2589 # Turn on stack trace.
2590 $stack[$stack_depth] |= 1;
2591 # XXX weird stack fram management?
2592 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2596 =head4 C<R> - restart
2598 Restarting the debugger is a complex operation that occurs in several phases.
2599 First, we try to reconstruct the command line that was used to invoke Perl
2604 # R - restart execution.
2605 $cmd =~ /^R$/ && do {
2606 # I may not be able to resurrect you, but here goes ...
2608 "Warning: some settings and command-line options may be lost!\n";
2609 my (@script, @flags, $cl);
2611 # If warn was on before, turn it on again.
2612 push @flags, '-w' if $ini_warn;
2614 # Rebuild the -I flags that were on the initial
2617 push @flags, '-I', $_;
2620 # Turn on taint if it was on before.
2621 push @flags, '-T' if ${^TAINT};
2623 # Arrange for setting the old INC:
2624 # Save the current @init_INC in the environment.
2625 set_list("PERLDB_INC", @ini_INC);
2627 # If this was a perl one-liner, go to the "file"
2628 # corresponding to the one-liner read all the lines
2629 # out of it (except for the first one, which is going
2630 # to be added back on again when 'perl -d' runs: that's
2631 # the 'require perl5db.pl;' line), and add them back on
2632 # to the command line to be executed.
2634 for (1 .. $#{'::_<-e'}) { # The first line is PERL5DB
2635 chomp($cl = ${'::_<-e'}[$_]);
2636 push @script, '-e', $cl;
2638 } ## end if ($0 eq '-e')
2640 # Otherwise we just reuse the original name we had
2648 After the command line has been reconstructed, the next step is to save
2649 the debugger's status in environment variables. The C<DB::set_list> routine
2650 is used to save aggregate variables (both hashes and arrays); scalars are
2651 just popped into environment variables directly.
2655 # If the terminal supported history, grab it and
2656 # save that in the environment.
2657 set_list("PERLDB_HIST",
2658 $term->Features->{getHistory}
2661 # Find all the files that were visited during this
2662 # session (i.e., the debugger had magic hashes
2663 # corresponding to them) and stick them in the environment.
2664 my @had_breakpoints = keys %had_breakpoints;
2665 set_list("PERLDB_VISITED", @had_breakpoints);
2667 # Save the debugger options we chose.
2668 set_list("PERLDB_OPT", %option);
2670 # Save the break-on-loads.
2671 set_list("PERLDB_ON_LOAD", %break_on_load);
2675 The most complex part of this is the saving of all of the breakpoints. They
2676 can live in an awful lot of places, and we have to go through all of them,
2677 find the breakpoints, and then save them in the appropriate environment
2678 variable via C<DB::set_list>.
2682 # Go through all the breakpoints and make sure they're
2685 for (0 .. $#had_breakpoints) {
2686 # We were in this file.
2687 my $file = $had_breakpoints[$_];
2689 # Grab that file's magic line hash.
2690 *dbline = $main::{ '_<' . $file };
2692 # Skip out if it doesn't exist, or if the breakpoint
2693 # is in a postponed file (we'll do postponed ones
2695 next unless %dbline or $postponed_file{$file};
2697 # In an eval. This is a little harder, so we'll
2698 # do more processing on that below.
2699 (push @hard, $file), next
2700 if $file =~ /^\(\w*eval/;
2701 # XXX I have no idea what this is doing. Yet.
2703 @add = %{ $postponed_file{$file} }
2704 if $postponed_file{$file};
2706 # Save the list of all the breakpoints for this file.
2707 set_list("PERLDB_FILE_$_", %dbline, @add);
2708 } ## end for (0 .. $#had_breakpoints)
2710 # The breakpoint was inside an eval. This is a little
2711 # more difficult. XXX and I don't understand it.
2713 # Get over to the eval in question.
2714 *dbline = $main::{ '_<' . $_ };
2715 my ($quoted, $sub, %subs, $line) = quotemeta $_;
2716 for $sub (keys %sub) {
2717 next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/;
2718 $subs{$sub} = [$1, $2];
2722 "No subroutines in $_, ignoring breakpoints.\n";
2725 LINES: for $line (keys %dbline) {
2727 # One breakpoint per sub only:
2728 my ($offset, $sub, $found);
2729 SUBS: for $sub (keys %subs) {
2732 $line # Not after the subroutine
2734 not defined $offset # Not caught
2740 $offset = $line - $subs{$sub}->[0];
2741 $offset = "+$offset", last SUBS
2743 } ## end if ($subs{$sub}->[1] >=...
2744 } ## end for $sub (keys %subs)
2745 if (defined $offset) {
2746 $postponed{$found} =
2747 "break $offset if $dbline{$line}";
2751 "Breakpoint in $_:$line ignored: after all the subroutines.\n";
2753 } ## end for $line (keys %dbline)
2754 } ## end for (@hard)
2756 # Save the other things that don't need to be
2758 set_list("PERLDB_POSTPONE", %postponed);
2759 set_list("PERLDB_PRETYPE", @$pretype);
2760 set_list("PERLDB_PRE", @$pre);
2761 set_list("PERLDB_POST", @$post);
2762 set_list("PERLDB_TYPEAHEAD", @typeahead);
2764 # We are oficially restarting.
2765 $ENV{PERLDB_RESTART} = 1;
2767 # We are junking all child debuggers.
2768 delete $ENV{PERLDB_PIDS}; # Restore ini state
2770 # Set this back to the initial pid.
2771 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
2775 After all the debugger status has been saved, we take the command we built
2776 up and then C<exec()> it. The debugger will spot the C<PERLDB_RESTART>
2777 environment variable and realize it needs to reload its state from the
2782 # And run Perl again. Add the "-d" flag, all the
2783 # flags we built up, the script (whether a one-liner
2784 # or a file), add on the -emacs flag for a slave editor,
2785 # and then the old arguments. We use exec() to keep the
2786 # PID stable (and that way $ini_pids is still valid).
2787 exec($^X, '-d', @flags, @script,
2788 ($slave_editor ? '-emacs' : ()), @ARGS) ||
2789 print $OUT "exec failed: $!\n";
2793 =head4 C<T> - stack trace
2795 Just calls C<DB::print_trace>.
2799 $cmd =~ /^T$/ && do {
2800 print_trace($OUT, 1); # skip DB
2804 =head4 C<w> - List window around current line.
2806 Just calls C<DB::cmd_w>.
2810 $cmd =~ /^w\b\s*(.*)/s && do { &cmd_w('w', $1); next CMD; };
2812 =head4 C<W> - watch-expression processing.
2814 Just calls C<DB::cmd_W>.
2818 $cmd =~ /^W\b\s*(.*)/s && do { &cmd_W('W', $1); next CMD; };
2820 =head4 C</> - search forward for a string in the source
2822 We take the argument and treat it as a pattern. If it turns out to be a
2823 bad one, we return the error we got from trying to C<eval> it and exit.
2824 If not, we create some code to do the search and C<eval> it so it can't
2829 $cmd =~ /^\/(.*)$/ && do {
2831 # The pattern as a string.
2834 # Remove the final slash.
2835 $inpat =~ s:([^\\])/$:$1:;
2837 # If the pattern isn't null ...
2840 # Turn of warn and die procesing for a bit.
2841 local $SIG{__DIE__};
2842 local $SIG{__WARN__};
2844 # Create the pattern.
2845 eval '$inpat =~ m' . "\a$inpat\a";
2847 # Oops. Bad pattern. No biscuit.
2848 # Print the eval error and go back for more
2854 } ## end if ($inpat ne "")
2856 # Set up to stop on wrap-around.
2859 # Don't move off the current line.
2862 # Done in eval so nothing breaks if the pattern
2863 # does something weird.
2866 # Move ahead one line.
2869 # Wrap if we pass the last line.
2870 $start = 1 if ($start > $max);
2872 # Stop if we have gotten back to this line again,
2873 last if ($start == $end);
2875 # A hit! (Note, though, that we are doing
2876 # case-insensitive matching. Maybe a qr//
2877 # expression would be better, so the user could
2878 # do case-sensitive matching if desired.
2879 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2880 if ($slave_editor) {
2881 # Handle proper escaping in the slave.
2882 print $OUT "\032\032$filename:$start:0\n";
2885 # Just print the line normally.
2886 print $OUT "$start:\t",$dbline[$start],"\n";
2888 # And quit since we found something.
2892 # If we wrapped, there never was a match.
2893 print $OUT "/$pat/: not found\n" if ($start == $end);
2897 =head4 C<?> - search backward for a string in the source
2899 Same as for C</>, except the loop runs backwards.
2903 # ? - backward pattern search.
2904 $cmd =~ /^\?(.*)$/ && do {
2906 # Get the pattern, remove trailing question mark.
2908 $inpat =~ s:([^\\])\?$:$1:;
2910 # If we've got one ...
2913 # Turn off die & warn handlers.
2914 local $SIG{__DIE__};
2915 local $SIG{__WARN__};
2916 eval '$inpat =~ m' . "\a$inpat\a";
2919 # Ouch. Not good. Print the error.
2924 } ## end if ($inpat ne "")
2926 # Where we are now is where to stop after wraparound.
2929 # Don't move away from this line.
2932 # Search inside the eval to prevent pattern badness
2939 # Wrap if we pass the first line.
2940 $start = $max if ($start <= 0);
2942 # Quit if we get back where we started,
2943 last if ($start == $end);
2946 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2947 if ($slave_editor) {
2948 # Yep, follow slave editor requirements.
2949 print $OUT "\032\032$filename:$start:0\n";
2952 # Yep, just print normally.
2953 print $OUT "$start:\t",$dbline[$start],"\n";
2961 # Say we failed if the loop never found anything,
2962 print $OUT "?$pat?: not found\n" if ($start == $end);
2966 =head4 C<$rc> - Recall command
2968 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2969 that the terminal supports history). It find the the command required, puts it
2970 into C<$cmd>, and redoes the loop to execute it.
2974 # $rc - recall command.
2975 $cmd =~ /^$rc+\s*(-)?(\d+)?$/ && do {
2977 # No arguments, take one thing off history.
2978 pop (@hist) if length($cmd) > 1;
2980 # Relative (- found)?
2981 # Y - index back from most recent (by 1 if bare minus)
2982 # N - go to that particular command slot or the last
2983 # thing if nothing following.
2984 $i = $1 ? ($#hist - ($2 || 1)) : ($2 || $#hist);
2986 # Pick out the command desired.
2989 # Print the command to be executed and restart the loop
2990 # with that command in the buffer.
2991 print $OUT $cmd, "\n";
2995 =head4 C<$sh$sh> - C<system()> command
2997 Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
2998 C<STDOUT> from getting messed up.
3002 # $sh$sh - run a shell command (if it's all ASCII).
3003 # Can't run shell commands with Unicode in the debugger, hmm.
3004 $cmd =~ /^$sh$sh\s*([\x00-\xff]*)/ && do {
3010 =head4 C<$rc I<pattern> $rc> - Search command history
3012 Another command to manipulate C<@hist>: this one searches it with a pattern.
3013 If a command is found, it is placed in C<$cmd> and executed via <redo>.
3017 # $rc pattern $rc - find a command in the history.
3018 $cmd =~ /^$rc([^$rc].*)$/ && do {
3019 # Create the pattern to use.
3022 # Toss off last entry if length is >1 (and it always is).
3023 pop (@hist) if length($cmd) > 1;
3025 # Look backward through the history.
3026 for ($i = $#hist ; $i ; --$i) {
3027 # Stop if we find it.
3028 last if $hist[$i] =~ /$pat/;
3033 print $OUT "No such command!\n\n";
3037 # Found it. Put it in the buffer, print it, and process it.
3039 print $OUT $cmd, "\n";
3043 =head4 C<$sh> - Invoke a shell
3045 Uses C<DB::system> to invoke a shell.
3049 # $sh - start a shell.
3050 $cmd =~ /^$sh$/ && do {
3051 # Run the user's shell. If none defined, run Bourne.
3052 # We resume execution when the shell terminates.
3053 &system($ENV{SHELL} || "/bin/sh");
3057 =head4 C<$sh I<command>> - Force execution of a command in a shell
3059 Like the above, but the command is passed to the shell. Again, we use
3060 C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
3064 # $sh command - start a shell and run a command in it.
3065 $cmd =~ /^$sh\s*([\x00-\xff]*)/ && do {
3066 # XXX: using csh or tcsh destroys sigint retvals!
3067 #&system($1); # use this instead
3069 # use the user's shell, or Bourne if none defined.
3070 &system($ENV{SHELL} || "/bin/sh", "-c", $1);
3074 =head4 C<H> - display commands in history
3076 Prints the contents of C<@hist> (if any).
3080 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
3081 # Anything other than negative numbers is ignored by
3082 # the (incorrect) pattern, so this test does nothing.
3083 $end = $2 ? ($#hist - $2) : 0;
3085 # Set to the minimum if less than zero.
3086 $hist = 0 if $hist < 0;
3088 # Start at the end of the array.
3089 # Stay in while we're still above the ending value.
3090 # Tick back by one each time around the loop.
3091 for ($i = $#hist ; $i > $end ; $i--) {
3093 # Print the command unless it has no arguments.
3094 print $OUT "$i: ", $hist[$i], "\n"
3095 unless $hist[$i] =~ /^.?$/;
3100 =head4 C<man, doc, perldoc> - look up documentation
3102 Just calls C<runman()> to print the appropriate document.
3106 # man, perldoc, doc - show manual pages.
3107 $cmd =~ /^(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?$/ && do {
3114 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3115 the bottom of the loop.
3119 # p - print (no args): print $_.
3120 $cmd =~ s/^p$/print {\$DB::OUT} \$_/;
3122 # p - print the given expression.
3123 $cmd =~ s/^p\b/print {\$DB::OUT} /;
3125 =head4 C<=> - define command alias
3127 Manipulates C<%alias> to add or list command aliases.
3131 # = - set up a command alias.
3132 $cmd =~ s/^=\s*// && do {
3134 if (length $cmd == 0) {
3135 # No args, get current aliases.
3136 @keys = sort keys %alias;
3138 elsif (my ($k, $v) = ($cmd =~ /^(\S+)\s+(\S.*)/)) {
3139 # Creating a new alias. $k is alias name, $v is
3142 # can't use $_ or kill //g state
3143 for my $x ($k, $v) {
3144 # Escape "alarm" characters.
3148 # Substitute key for value, using alarm chars
3149 # as separators (which is why we escaped them in
3151 $alias{$k} = "s\a$k\a$v\a";
3153 # Turn off standard warn and die behavior.
3154 local $SIG{__DIE__};
3155 local $SIG{__WARN__};
3158 unless (eval "sub { s\a$k\a$v\a }; 1") {
3159 # Nope. Bad alias. Say so and get out.
3160 print $OUT "Can't alias $k to $v: $@\n";
3164 # We'll only list the new one.
3166 } ## end elsif (my ($k, $v) = ($cmd...
3168 # The argument is the alias to list.
3175 # Messy metaquoting: Trim the substiution code off.
3176 # We use control-G as the delimiter because it's not
3177 # likely to appear in the alias.
3178 if ((my $v = $alias{$k}) =~ s
\as\a$k\a(.*)\a$
\a1
\a) {
3180 print $OUT "$k\t= $1\n";
3182 elsif (defined $alias{$k}) {
3183 # Couldn't trim it off; just print the alias code.
3184 print $OUT "$k\t$alias{$k}\n";
3188 print "No alias for $k\n";
3190 } ## end for my $k (@keys)
3194 =head4 C<source> - read commands from a file.
3196 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3201 # source - read commands from a file (or pipe!) and execute.
3202 $cmd =~ /^source\s+(.*\S)/ && do {
3203 if (open my $fh, $1) {
3204 # Opened OK; stick it in the list of file handles.
3209 &warn("Can't execute `$1': $!\n");
3214 =head4 C<|, ||> - pipe output through the pager.
3216 FOR C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3217 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3218 pipe to the pager (restoring the output filehandles if this fails). If this
3219 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3220 set C<$signal>, sending us back into the debugger.
3222 We then trim off the pipe symbols and C<redo> the command loop at the
3223 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3228 # || - run command in the pager, with output to DB::OUT.
3229 $cmd =~ /^\|\|?\s*[^|]/ && do {
3230 if ($pager =~ /^\|/) {
3231 # Default pager is into a pipe. Redirect I/O.
3232 open(SAVEOUT, ">&STDOUT") ||
3233 &warn("Can't save STDOUT");
3234 open(STDOUT, ">&OUT") ||
3235 &warn("Can't redirect STDOUT");
3236 } ## end if ($pager =~ /^\|/)
3238 # Not into a pipe. STDOUT is safe.
3239 open(SAVEOUT, ">&OUT") || &warn("Can't save DB::OUT");
3242 # Fix up environment to record we have less if so.
3245 unless ($piped = open(OUT, $pager)) {
3246 # Couldn't open pipe to pager.
3247 &warn("Can't pipe output to `$pager'");
3248 if ($pager =~ /^\|/) {
3249 # Redirect I/O back again.
3250 open(OUT, ">&STDOUT") # XXX: lost message
3251 || &warn("Can't restore DB::OUT");
3252 open(STDOUT, ">&SAVEOUT") ||
3253 &warn("Can't restore STDOUT");
3255 } ## end if ($pager =~ /^\|/)
3257 # Redirect I/O. STDOUT already safe.
3258 open(OUT, ">&STDOUT") # XXX: lost message
3259 || &warn("Can't restore DB::OUT");
3262 } ## end unless ($piped = open(OUT,...
3264 # Set up broken-pipe handler if necessary.
3265 $SIG{PIPE} = \&DB::catch
3266 if $pager =~ /^\|/ &&
3267 ("" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE});
3269 # Save current filehandle, unbuffer out, and put it back.
3270 $selected = select(OUT);
3273 # Don't put it back if pager was a pipe.
3274 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
3276 # Trim off the pipe symbols and run the command now.
3277 $cmd =~ s/^\|+\s*//;
3282 =head3 END OF COMMAND PARSING
3284 Anything left in C<$cmd> at this point is a Perl expression that we want to
3285 evaluate. We'll always evaluate in the user's context, and fully qualify
3286 any variables we might want to address in the C<DB> package.
3290 # t - turn trace on.
3291 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3293 # s - single-step. Remember the last command was 's'.
3294 $cmd =~ s/^s\s/\$DB::single = 1;\n/ && do { $laststep = 's' };
3296 # n - single-step, but not into subs. Remember last command
3298 $cmd =~ s/^n\s/\$DB::single = 2;\n/ && do { $laststep = 'n' };
3302 # Make sure the flag that says "the debugger's running" is
3303 # still on, to make sure we get control again.
3304 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3306 # Run *our* eval that executes in the caller's context.
3309 # Turn off the one-time-dump stuff now.
3311 $onetimeDump = undef;
3312 $onetimedumpDepth = undef;
3314 elsif ($term_pid == $$) {
3315 # XXX If this is the master pid, print a newline.
3318 } ## end while (($term || &setterm...
3320 =head3 POST-COMMAND PROCESSING
3322 After each command, we check to see if the command output was piped anywhere.
3323 If so, we go through the necessary code to unhook the pipe and go back to
3324 our standard filehandles for input and output.
3330 # At the end of every command:
3332 # Unhook the pipe mechanism now.
3333 if ($pager =~ /^\|/) {
3334 # No error from the child.
3337 # we cannot warn here: the handle is missing --tchrist
3338 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
3340 # most of the $? crud was coping with broken cshisms
3341 # $? is explicitly set to 0, so this never runs.
3343 print SAVEOUT "Pager `$pager' failed: ";
3345 print SAVEOUT "shell returned -1\n";
3348 print SAVEOUT ($? & 127)
3349 ? " (SIG#" . ($? & 127) . ")"
3350 : "", ($? & 128) ? " -- core dumped" : "", "\n";
3353 print SAVEOUT "status ", ($? >> 8), "\n";
3357 # Reopen filehandle for our output (if we can) and
3358 # restore STDOUT (if we can).
3359 open(OUT, ">&STDOUT") || &warn("Can't restore DB::OUT");
3360 open(STDOUT, ">&SAVEOUT") ||
3361 &warn("Can't restore STDOUT");
3363 # Turn off pipe exception handler if necessary.
3364 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
3366 # Will stop ignoring SIGPIPE if done like nohup(1)
3367 # does SIGINT but Perl doesn't give us a choice.
3368 } ## end if ($pager =~ /^\|/)
3370 # Non-piped "pager". Just restore STDOUT.
3371 open(OUT, ">&SAVEOUT") || &warn("Can't restore DB::OUT");
3374 # Close filehandle pager was using, restore the normal one
3377 select($selected), $selected = "" unless $selected eq "";
3381 } ## end if ($piped)
3384 =head3 COMMAND LOOP TERMINATION
3386 When commands have finished executing, we come here. If the user closed the
3387 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3388 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3389 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3390 The interpreter will then execute the next line and then return control to us
3395 # No more commands? Quit.
3396 $fall_off_end = 1 unless defined $cmd; # Emulate `q' on EOF
3398 # Evaluate post-prompt commands.
3399 foreach $evalarg (@$post) {
3402 } # if ($single || $signal)
3404 # Put the user's globals back where you found them.
3405 ($@, $!, $^E, $,, $/, $\, $^W) = @saved;
3409 # The following code may be executed now:
3414 C<sub> is called whenever a subroutine call happens in the program being
3415 debugged. The variable C<$DB::sub> contains the name of the subroutine
3418 The core function of this subroutine is to actually call the sub in the proper
3419 context, capturing its output. This of course causes C<DB::DB> to get called
3420 again, repeating until the subroutine ends and returns control to C<DB::sub>
3421 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3422 return value, and returns its captured copy of the return value as its own
3423 return value. The value then feeds back into the program being debugged as if
3424 C<DB::sub> hadn't been there at all.
3426 C<sub> does all the work of printing the subroutine entry and exit messages
3427 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3428 and also prints the return value if needed (for the C<r> command and if
3429 the 16 bit is set in C<$frame>).
3431 It also tracks the subroutine call depth by saving the current setting of
3432 C<$single> in the C<@stack> package global; if this exceeds the value in
3433 C<$deep>, C<sub> automatically turns on printing of the current depth by
3434 setting the 4 bit in C<$single>. In any case, it keeps the current setting
3435 of stop/don't stop on entry to subs set as it currently is set.
3437 =head3 C<caller()> support
3439 If C<caller()> is called from the package C<DB>, it provides some
3440 additional data, in the following order:
3446 The package name the sub was in
3448 =item * C<$filename>
3450 The filename it was defined in
3454 The line number it was defined on
3456 =item * C<$subroutine>
3458 The subroutine name; C<'(eval)'> if an C<eval>().
3462 1 if it has arguments, 0 if not
3464 =item * C<$wantarray>
3466 1 if array context, 0 if scalar context
3468 =item * C<$evaltext>
3470 The C<eval>() text, if any (undefined for C<eval BLOCK>)
3472 =item * C<$is_require>
3474 frame was created by a C<use> or C<require> statement
3478 pragma information; subject to change between versions
3482 pragma information: subject to change between versions
3484 =item * C<@DB::args>
3486 arguments with which the subroutine was invoked
3494 # Whether or not the autoloader was running, a scalar to put the
3495 # sub's return value in (if needed), and an array to put the sub's
3496 # return value in (if needed).
3497 my ($al, $ret, @ret) = "";
3499 # If the last ten characters are C'::AUTOLOAD', note we've traced
3500 # into AUTOLOAD for $sub.
3501 if (length($sub) > 10 && substr($sub, -10, 10) eq '::AUTOLOAD') {
3505 # We stack the stack pointer and then increment it to protect us
3506 # from a situation that might unwind a whole bunch of call frames
3507 # at once. Localizing the stack pointer means that it will automatically
3508 # unwind the same amount when multiple stack frames are unwound.
3509 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3512 $#stack = $stack_depth;
3514 # Save current single-step setting.
3515 $stack[-1] = $single;
3517 # Turn off all flags except single-stepping.
3520 # If we've gotten really deeply recursed, turn on the flag that will
3521 # make us stop with the 'deep recursion' message.
3522 $single |= 4 if $stack_depth == $deep;
3524 # If frame messages are on ...
3526 $frame & 4 # Extended frame entry message
3528 print_lineinfo(' ' x ($stack_depth - 1), "in "),
3530 # Why -1? But it works! :-(
3531 # Because print_trace will call add 1 to it and then call
3532 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3534 print_trace($LINEINFO, -1, 1, 1, "$sub$al")
3536 : print_lineinfo(' ' x ($stack_depth - 1), "entering $sub$al\n")
3537 # standard frame entry message
3541 # Determine the sub's return type,and capture approppriately.
3543 # Called in array context. call sub and capture output.
3544 # DB::DB will recursively get control again if appropriate; we'll come
3545 # back here when the sub is finished.
3548 # Pop the single-step value back off the stack.
3549 $single |= $stack[$stack_depth--];
3551 # Check for exit trace messages...
3553 $frame & 4 # Extended exit message
3555 print_lineinfo(' ' x $stack_depth, "out "),
3556 print_trace($LINEINFO, -1, 1, 1, "$sub$al")
3558 : print_lineinfo(' ' x $stack_depth, "exited $sub$al\n")
3559 # Standard exit message
3563 # Print the return info if we need to.
3564 if ($doret eq $stack_depth or $frame & 16) {
3565 # Turn off output record separator.
3567 my $fh = ($doret eq $stack_depth ? $OUT : $LINEINFO);
3569 # Indent if we're printing because of $frame tracing.
3570 print $fh ' ' x $stack_depth if $frame & 16;
3572 # Print the return value.
3573 print $fh "list context return from $sub:\n";
3576 # And don't print it again.
3578 } ## end if ($doret eq $stack_depth...
3579 # And we have to return the return value now.
3582 } ## end if (wantarray)
3586 if (defined wantarray) {
3587 # Save the value if it's wanted at all.
3591 # Void return, explicitly.
3596 # Pop the single-step value off the stack.
3597 $single |= $stack[$stack_depth--];
3599 # If we're doing exit messages...
3601 $frame & 4 # Extended messsages
3603 print_lineinfo(' ' x $stack_depth, "out "),
3604 print_trace($LINEINFO, -1, 1, 1, "$sub$al")
3606 : print_lineinfo(' ' x $stack_depth, "exited $sub$al\n")
3611 # If we are supposed to show the return value... same as before.
3612 if ($doret eq $stack_depth or $frame & 16 and defined wantarray) {
3614 my $fh = ($doret eq $stack_depth ? $OUT : $LINEINFO);
3615 print $fh (' ' x $stack_depth) if $frame & 16;
3618 ? "scalar context return from $sub: "
3619 : "void context return from $sub\n"
3621 dumpit($fh, $ret) if defined wantarray;
3623 } ## end if ($doret eq $stack_depth...
3625 # Return the appropriate scalar value.
3627 } ## end else [ if (wantarray)
3630 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
3632 In Perl 5.8.0, there was a major realignment of the commands and what they did,
3633 Most of the changes were to systematize the command structure and to eliminate
3634 commands that threw away user input without checking.
3636 The following sections describe the code added to make it easy to support
3637 multiple command sets with conflicting command names. This section is a start
3638 at unifying all command processing to make it simpler to develop commands.
3640 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
3641 number, and C<$dbline> (the current line) as arguments.
3643 Support functions in this section which have multiple modes of failure C<die>
3644 on error; the rest simply return a false value.
3646 The user-interface functions (all of the C<cmd_*> functions) just output
3651 The C<%set> hash defines the mapping from command letter to subroutine
3654 C<%set> is a two-level hash, indexed by set name and then by command name.
3655 Note that trying to set the CommandSet to 'foobar' simply results in the
3656 5.8.0 command set being used, since there's no top-level entry for 'foobar'.
3665 'A' => 'pre580_null',
3667 'B' => 'pre580_null',
3668 'd' => 'pre580_null',
3671 'M' => 'pre580_null',
3673 'o' => 'pre580_null',
3679 '<' => 'pre590_prepost',
3680 '<<' => 'pre590_prepost',
3681 '>' => 'pre590_prepost',
3682 '>>' => 'pre590_prepost',
3683 '{' => 'pre590_prepost',
3684 '{{' => 'pre590_prepost',
3688 =head2 C<cmd_wrapper()> (API)
3690 C<cmd_wrapper()> allows the debugger to switch command sets
3691 depending on the value of the C<CommandSet> option.
3693 It tries to look up the command in the X<C<%set>> package-level I<lexical>
3694 (which means external entities can't fiddle with it) and create the name of
3695 the sub to call based on the value found in the hash (if it's there). I<All>
3696 of the commands to be handled in a set have to be added to C<%set>; if they
3697 aren't found, the 5.8.0 equivalent is called (if there is one).
3699 This code uses symbolic references.
3706 my $dblineno = shift;
3708 # Assemble the command subroutine's name by looking up the
3709 # command set and command name in %set. If we can't find it,
3710 # default to the older version of the command.
3712 . ( $set{$CommandSet}{$cmd}
3713 || ( $cmd =~ /^[<>{]+/o ? 'prepost' : $cmd ) );
3715 # Call the command subroutine, call it by name.
3716 return &$call($cmd, $line, $dblineno);
3717 } ## end sub cmd_wrapper
3719 =head3 C<cmd_a> (command)
3721 The C<a> command handles pre-execution actions. These are associated with a
3722 particular line, so they're stored in C<%dbline>. We default to the current
3723 line if none is specified.
3729 my $line = shift || ''; # [.|line] expr
3732 # If it's dot (here), or not all digits, use the current line.
3733 $line =~ s/^(\.|(?:[^\d]))/$dbline/;
3735 # Should be a line number followed by an expression.
3736 if ($line =~ /^\s*(\d*)\s*(\S.+)/) {
3737 my ($lineno, $expr) = ($1, $2);
3739 # If we have an expression ...
3741 # ... but the line isn't breakable, complain.
3742 if ($dbline[$lineno] == 0) {
3744 "Line $lineno($dbline[$lineno]) does not have an action?\n";
3747 # It's executable. Record that the line has an action.
3748 $had_breakpoints{$filename} |= 2;
3750 # Remove any action, temp breakpoint, etc.
3751 $dbline{$lineno} =~ s/\0[^\0]*//;
3753 # Add the action to the line.
3754 $dbline{$lineno} .= "\0" . action($expr);
3756 } ## end if (length $expr)
3757 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
3761 "Adding an action requires an optional lineno and an expression\n"
3766 =head3 C<cmd_A> (command)
3768 Delete actions. Similar to above, except the delete code is in a separate
3769 subroutine, C<delete_action>.
3775 my $line = shift || '';
3779 $line =~ s/^\./$dbline/;
3781 # Call delete_action with a null param to delete them all.
3782 # The '1' forces the eval to be true. It'll be false only
3783 # if delete_action blows up for some reason, in which case
3784 # we print $@ and get out.
3786 eval { &delete_action(); 1 } or print $OUT $@ and return;
3789 # There's a real line number. Pass it to delete_action.
3790 # Error trapping is as above.
3791 elsif ($line =~ /^(\S.*)/) {
3792 eval { &delete_action($1); 1 } or print $OUT $@ and return;
3795 # Swing and a miss. Bad syntax.
3798 "Deleting an action requires a line number, or '*' for all\n"
3803 =head3 C<delete_action> (API)
3805 C<delete_action> accepts either a line number or C<undef>. If a line number
3806 is specified, we check for the line being executable (if it's not, it
3807 couldn't have had an action). If it is, we just take the action off (this
3808 will get any kind of an action, including breakpoints).
3816 die "Line $i has no action .\n" if $dbline[$i] == 0;
3818 # Nuke whatever's there.
3819 $dbline{$i} =~ s/\0[^\0]*//; # \^a
3820 delete $dbline{$i} if $dbline{$i} eq '';
3823 print $OUT "Deleting all actions...\n";
3824 for my $file (keys %had_breakpoints) {
3825 local *dbline = $main::{ '_<' . $file };
3828 for ($i = 1 ; $i <= $max ; $i++) {
3829 if (defined $dbline{$i}) {
3830 $dbline{$i} =~ s/\0[^\0]*//;
3831 delete $dbline{$i} if $dbline{$i} eq '';
3833 unless ($had_breakpoints{$file} &= ~2) {
3834 delete $had_breakpoints{$file};
3836 } ## end for ($i = 1 ; $i <= $max...
3837 } ## end for my $file (keys %had_breakpoints)
3838 } ## end else [ if (defined($i))
3839 } ## end sub delete_action
3841 =head3 C<cmd_b> (command)
3843 Set breakpoints. Since breakpoints can be set in so many places, in so many
3844 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
3845 we try to parse the command type, and then shuttle it off to an appropriate
3846 subroutine to actually do the work of setting the breakpoint in the right
3853 my $line = shift; # [.|line] [cond]
3856 # Make . the current line number if it's there..
3857 $line =~ s/^\./$dbline/;
3859 # No line number, no condition. Simple break on current line.
3860 if ($line =~ /^\s*$/) {
3861 &cmd_b_line($dbline, 1);
3864 # Break on load for a file.
3865 elsif ($line =~ /^load\b\s*(.*)/) {
3871 # b compile|postpone <some sub> [<condition>]
3872 # The interpreter actually traps this one for us; we just put the
3873 # necessary condition in the %postponed hash.
3874 elsif ($line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/) {
3875 # Capture the condition if there is one. Make it true if none.
3876 my $cond = length $3 ? $3 : '1';
3878 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
3879 # if it was 'compile'.
3880 my ($subname, $break) = ($2, $1 eq 'postpone');
3882 # De-Perl4-ify the name - ' separators to ::.
3883 $subname =~ s/\'/::/g;
3885 # Qualify it into the current package unless it's already qualified.
3886 $subname = "${'package'}::" . $subname unless $subname =~ /::/;
3888 # Add main if it starts with ::.
3889 $subname = "main" . $subname if substr($subname, 0, 2) eq "::";
3891 # Save the break type for this sub.
3892 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
3893 } ## end elsif ($line =~ ...
3895 # b <sub name> [<condition>]
3896 elsif ($line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/) {
3899 $cond = length $2 ? $2 : '1';
3900 &cmd_b_sub($subname, $cond);
3903 # b <line> [<condition>].
3904 elsif ($line =~ /^(\d*)\s*(.*)/) {
3905 # Capture the line. If none, it's the current line.
3906 $line = $1 || $dbline;
3908 # If there's no condition, make it '1'.
3909 $cond = length $2 ? $2 : '1';
3912 &cmd_b_line($line, $cond);
3915 # Line didn't make sense.
3917 print "confused by line($line)?\n";
3921 =head3 C<break_on_load> (API)
3923 We want to break when this file is loaded. Mark this file in the
3924 C<%break_on_load> hash, and note that it has a breakpoint in
3925 C<%had_breakpoints>.
3931 $break_on_load{$file} = 1;
3932 $had_breakpoints{$file} |= 1;
3935 =head3 C<report_break_on_load> (API)
3937 Gives us an array of filenames that are set to break on load. Note that
3938 only files with break-on-load are in here, so simply showing the keys
3943 sub report_break_on_load {
3944 sort keys %break_on_load;
3947 =head3 C<cmd_b_load> (command)
3949 We take the file passed in and try to find it in C<%INC> (which maps modules
3950 to files they came from). We mark those files for break-on-load via
3951 C<break_on_load> and then report that it was done.
3959 # This is a block because that way we can use a redo inside it
3960 # even without there being any looping structure at all outside it.
3962 # Save short name and full path if found.
3964 push @files, $::INC{$file} if $::INC{$file};
3966 # Tack on .pm and do it again unless there was a '.' in the name
3968 $file .= '.pm', redo unless $file =~ /\./;
3971 # Do the real work here.
3972 break_on_load($_) for @files;
3974 # All the files that have break-on-load breakpoints.
3975 @files = report_break_on_load;
3977 # Normalize for the purposes of our printing this.
3980 print $OUT "Will stop on load of `@files'.\n";
3981 } ## end sub cmd_b_load
3983 =head3 C<$filename_error> (API package global)
3985 Several of the functions we need to implement in the API need to work both
3986 on the current file and on other files. We don't want to duplicate code, so
3987 C<$filename_error> is used to contain the name of the file that's being
3988 worked on (if it's not the current one).
3990 We can now build functions in pairs: the basic function works on the current
3991 file, and uses C<$filename_error> as part of its error message. Since this is
3992 initialized to C<''>, no filename will appear when we are working on the
3995 The second function is a wrapper which does the following:
3999 =item * Localizes C<$filename_error> and sets it to the name of the file to be processed.
4001 =item * Locaizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4003 =item * Calls the first function.
4005 The first function works on the "current" (i.e., the one we changed to) file,
4006 and prints C<$filename_error> in the error message (the name of the other file)
4007 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
4008 restored to C<''>. This restores everything to the way it was before the
4009 second function was called at all.
4011 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4016 $filename_error = '';
4018 =head3 breakable_line($from, $to) (API)
4020 The subroutine decides whether or not a line in the current file is breakable.
4021 It walks through C<@dbline> within the range of lines specified, looking for
4022 the first line that is breakable.
4024 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4025 first line I<after> C<$to> that's breakable, if there is one.
4027 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4028 first line I<before> C<$to> that's breakable, if there is one.
4032 sub breakable_line {
4034 my ($from, $to) = @_;
4036 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4039 # If there are at least 2 arguments, we're trying to search a range.
4042 # $delta is positive for a forward search, negative for a backward one.
4043 my $delta = $from < $to ? +1 : -1;
4045 # Keep us from running off the ends of the file.
4046 my $limit = $delta > 0 ? $#dbline : 1;
4048 # Clever test. If you're a mathematician, it's obvious why this
4049 # test works. If not:
4050 # If $delta is positive (going forward), $limit will be $#dbline.
4051 # If $to is less than $limit, ($limit - $to) will be positive, times
4052 # $delta of 1 (positive), so the result is > 0 and we should use $to
4053 # as the stopping point.
4055 # If $to is greater than $limit, ($limit - $to) is negative,
4056 # times $delta of 1 (positive), so the result is < 0 and we should
4057 # use $limit ($#dbline) as the stopping point.
4059 # If $delta is negative (going backward), $limit will be 1.
4060 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4061 # (negative) so the result is > 0, and we use $to as the stopping
4064 # If $to is less than zero, ($limit - $to) will be positive,
4065 # times $delta of -1 (negative), so the result is not > 0, and
4066 # we use $limit (1) as the stopping point.
4068 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4069 # (negative), still giving zero; the result is not > 0, and
4070 # we use $limit (1) as the stopping point.
4072 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4073 # (negative), giving a positive (>0) value, so we'll set $limit to
4076 $limit = $to if ($limit - $to) * $delta > 0;
4078 # The real search loop.
4079 # $i starts at $from (the point we want to start searching from).
4080 # We move through @dbline in the appropriate direction (determined
4081 # by $delta: either -1 (back) or +1 (ahead).
4082 # We stay in as long as we haven't hit an executable line
4083 # ($dbline[$i] == 0 means not executable) and we haven't reached
4084 # the limit yet (test similar to the above).
4085 $i += $delta while $dbline[$i] == 0 and ($limit - $i) * $delta > 0;
4087 } ## end if (@_ >= 2)
4089 # If $i points to a line that is executable, return that.
4090 return $i unless $dbline[$i] == 0;
4092 # Format the message and print it: no breakable lines in range.
4093 my ($pl, $upto) = ('', '');
4094 ($pl, $upto) = ('s', "..$to") if @_ >= 2 and $from != $to;
4096 # If there's a filename in filename_error, we'll see it.
4098 die "Line$pl $from$upto$filename_error not breakable\n";
4099 } ## end sub breakable_line
4101 =head3 breakable_line_in_filename($file, $from, $to) (API)
4103 Like C<breakable_line>, but look in another file.
4107 sub breakable_line_in_filename {
4108 # Capture the file name.
4111 # Swap the magic line array over there temporarily.
4112 local *dbline = $main::{ '_<' . $f };
4114 # If there's an error, it's in this other file.
4115 local $filename_error = " of `$f'";
4117 # Find the breakable line.
4120 # *dbline and $filename_error get restored when this block ends.
4122 } ## end sub breakable_line_in_filename
4124 =head3 break_on_line(lineno, [condition]) (API)
4126 Adds a breakpoint with the specified codition (or 1 if no condition was
4127 specified) to the specified line. Dies if it can't.
4132 my ($i, $cond) = @_;
4134 # Always true if no condition supplied.
4135 $cond = 1 unless @_ >= 2;
4141 # Woops, not a breakable line. $filename_error allows us to say
4142 # if it was in a different file.
4143 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4145 # Mark this file as having breakpoints in it.
4146 $had_breakpoints{$filename} |= 1;
4148 # If there is an action or condition here already ...
4150 # ... swap this condition for the existing one.
4151 $dbline{$i} =~ s/^[^\0]*/$cond/;
4154 # Nothing here - just add the condition.
4155 $dbline{$i} = $cond;
4157 } ## end sub break_on_line
4159 =head3 cmd_b_line(line, [condition]) (command)
4161 Wrapper for C<break_on_line>. Prints the failure message if it
4167 eval { break_on_line(@_); 1 } or do {
4169 print $OUT $@ and return;
4171 } ## end sub cmd_b_line
4173 =head3 break_on_filename_line(file, line, [condition]) (API)
4175 Switches to the file specified and then calls C<break_on_line> to set
4180 sub break_on_filename_line {
4181 my ($f, $i, $cond) = @_;
4183 # Always true if condition left off.
4184 $cond = 1 unless @_ >= 3;
4186 # Switch the magical hash temporarily.
4187 local *dbline = $main::{ '_<' . $f };
4189 # Localize the variables that break_on_line uses to make its message.
4190 local $filename_error = " of `$f'";
4191 local $filename = $f;
4193 # Add the breakpoint.
4194 break_on_line($i, $cond);
4195 } ## end sub break_on_filename_line
4197 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4199 Switch to another file, search the range of lines specified for an
4200 executable one, and put a breakpoint on the first one you find.
4204 sub break_on_filename_line_range {
4205 my ($f, $from, $to, $cond) = @_;
4207 # Find a breakable line if there is one.
4208 my $i = breakable_line_in_filename($f, $from, $to);
4210 # Always true if missing.
4211 $cond = 1 unless @_ >= 3;
4213 # Add the breakpoint.
4214 break_on_filename_line($f, $i, $cond);
4215 } ## end sub break_on_filename_line_range
4217 =head3 subroutine_filename_lines(subname, [condition]) (API)
4219 Search for a subroutine within a given file. The condition is ignored.
4220 Uses C<find_sub> to locate the desired subroutine.
4224 sub subroutine_filename_lines {
4225 my ($subname, $cond) = @_;
4227 # Returned value from find_sub() is fullpathname:startline-endline.
4228 # The match creates the list (fullpathname, start, end). Falling off
4229 # the end of the subroutine returns this implicitly.
4230 find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/;
4231 } ## end sub subroutine_filename_lines
4233 =head3 break_subroutine(subname) (API)
4235 Places a break on the first line possible in the specified subroutine. Uses
4236 C<subroutine_filename_lines> to find the subroutine, and
4237 C<break_on_filename_line_range> to place the break.
4241 sub break_subroutine {
4242 my $subname = shift;
4244 # Get filename, start, and end.
4245 my ($file, $s, $e) = subroutine_filename_lines($subname)
4246 or die "Subroutine $subname not found.\n";
4248 # Null condition changes to '1' (always true).
4249 $cond = 1 unless @_ >= 2;
4251 # Put a break the first place possible in the range of lines
4252 # that make up this subroutine.
4253 break_on_filename_line_range($file, $s, $e, @_);
4254 } ## end sub break_subroutine
4256 =head3 cmd_b_sub(subname, [condition]) (command)
4258 We take the incoming subroutine name and fully-qualify it as best we can.
4262 =item 1. If it's already fully-qualified, leave it alone.
4264 =item 2. Try putting it in the current package.
4266 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
4268 =item 4. If it starts with '::', put it in 'main::'.
4272 After all this cleanup, we call C<break_subroutine> to try to set the
4278 my ($subname, $cond) = @_;
4280 # Add always-true condition if we have none.
4281 $cond = 1 unless @_ >= 2;
4283 # If the subname isn't a code reference, qualify it so that
4284 # break_subroutine() will work right.
4285 unless (ref $subname eq 'CODE') {
4287 $subname =~ s/\'/::/g;
4290 # Put it in this package unless it's already qualified.
4291 $subname = "${'package'}::" . $subname
4292 unless $subname =~ /::/;
4294 # Requalify it into CORE::GLOBAL if qualifying it into this
4295 # package resulted in its not being defined, but only do so
4296 # if it really is in CORE::GLOBAL.
4297 $subname = "CORE::GLOBAL::$s"
4298 if not defined &$subname
4300 and defined &{"CORE::GLOBAL::$s"};
4302 # Put it in package 'main' if it has a leading ::.
4303 $subname = "main" . $subname if substr($subname, 0, 2) eq "::";
4305 } ## end unless (ref $subname eq 'CODE')
4307 # Try to set the breakpoint.
4308 eval { break_subroutine($subname, $cond); 1 } or do {
4310 print $OUT $@ and return;
4312 } ## end sub cmd_b_sub
4314 =head3 C<cmd_B> - delete breakpoint(s) (command)
4316 The command mostly parses the command line and tries to turn the argument
4317 into a line spec. If it can't, it uses the current line. It then calls
4318 C<delete_breakpoint> to actually do the work.
4320 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
4321 thereby deleting all the breakpoints.
4328 # No line spec? Use dbline.
4329 # If there is one, use it if it's non-zero, or wipe it out if it is.
4330 my $line = ($_[0] =~ /^\./) ? $dbline : shift || '';
4333 # If the line was dot, make the line the current one.
4334 $line =~ s/^\./$dbline/;
4336 # If it's * we're deleting all the breakpoints.
4338 eval { &delete_breakpoint(); 1 } or print $OUT $@ and return;
4341 # If there is a line spec, delete the breakpoint on that line.
4342 elsif ($line =~ /^(\S.*)/) {
4343 eval { &delete_breakpoint($line || $dbline); 1 } or do {
4345 print $OUT $@ and return;
4347 } ## end elsif ($line =~ /^(\S.*)/)
4352 "Deleting a breakpoint requires a line number, or '*' for all\n"
4357 =head3 delete_breakpoint([line]) (API)
4359 This actually does the work of deleting either a single breakpoint, or all
4362 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
4363 just drop out with a message saying so. If it is, we remove the condition
4364 part of the 'condition\0action' that says there's a breakpoint here. If,
4365 after we've done that, there's nothing left, we delete the corresponding
4366 line in C<%dbline> to signal that no action needs to be taken for this line.
4368 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
4369 which lists all currently-loaded files which have breakpoints. We then look
4370 at each line in each of these files, temporarily switching the C<%dbline>
4371 and C<@dbline> structures to point to the files in question, and do what
4372 we did in the single line case: delete the condition in C<@dbline>, and
4373 delete the key in C<%dbline> if nothing's left.
4375 We then wholesale delete C<%postponed>, C<%postponed_file>, and
4376 C<%break_on_load>, because these structures contain breakpoints for files
4377 and code that haven't been loaded yet. We can just kill these off because there
4378 are no magical debugger structures associated with them.
4382 sub delete_breakpoint {
4385 # If we got a line, delete just that one.
4388 # Woops. This line wasn't breakable at all.
4389 die "Line $i not breakable.\n" if $dbline[$i] == 0;
4391 # Kill the condition, but leave any action.
4392 $dbline{$i} =~ s/^[^\0]*//;
4394 # Remove the entry entirely if there's no action left.
4395 delete $dbline{$i} if $dbline{$i} eq '';
4398 # No line; delete them all.
4400 print $OUT "Deleting all breakpoints...\n";
4402 # %had_breakpoints lists every file that had at least one
4404 for my $file (keys %had_breakpoints) {
4405 # Switch to the desired file temporarily.
4406 local *dbline = $main::{ '_<' . $file };
4411 # For all lines in this file ...
4412 for ($i = 1 ; $i <= $max ; $i++) {
4413 # If there's a breakpoint or action on this line ...
4414 if (defined $dbline{$i}) {
4415 # ... remove the breakpoint.
4416 $dbline{$i} =~ s/^[^\0]+//;
4417 if ($dbline{$i} =~ s/^\0?$//) {
4418 # Remove the entry altogether if no action is there.
4421 } ## end if (defined $dbline{$i...
4422 } ## end for ($i = 1 ; $i <= $max...
4424 # If, after we turn off the "there were breakpoints in this file"
4425 # bit, the entry in %had_breakpoints for this file is zero,
4426 # we should remove this file from the hash.
4427 if (not $had_breakpoints{$file} &= ~1) {
4428 delete $had_breakpoints{$file};
4430 } ## end for my $file (keys %had_breakpoints)
4432 # Kill off all the other breakpoints that are waiting for files that
4433 # haven't been loaded yet.
4435 undef %postponed_file;
4436 undef %break_on_load;
4437 } ## end else [ if (defined($i))
4438 } ## end sub delete_breakpoint
4440 =head3 cmd_stop (command)
4442 This is meant to be part of the new command API, but it isn't called or used
4443 anywhere else in the debugger. XXX It is probably meant for use in development
4448 sub cmd_stop { # As on ^C, but not signal-safy.
4452 =head3 C<cmd_h> - help command (command)
4454 Does the work of either
4458 =item * Showing all the debugger help
4460 =item * Showing help for a specific command
4469 # If we have no operand, assume null.
4470 my $line = shift || '';
4472 # 'h h'. Print the long-format help.
4473 if ($line =~ /^h\s*/) {
4477 # 'h <something>'. Search for the command and print only its help.
4478 elsif ($line =~ /^(\S.*)$/) {
4480 # support long commands; otherwise bogus errors
4481 # happen when you ask for h on <CR> for example
4482 my $asked = $1; # the command requested
4483 # (for proper error message)
4485 my $qasked = quotemeta($asked); # for searching; we don't
4486 # want to use it as a pattern.
4487 # XXX: finds CR but not <CR>
4489 # Search the help string for the command.
4490 if ($help =~ /^ # Start of a line
4492 (?:[IB]<) # Optional markup
4493 $qasked # The requested command
4495 # It's there; pull it out and print it.
4498 (?:[IB]<) # Optional markup
4499 $qasked # The command
4500 ([\s\S]*?) # Description line(s)
4501 \n) # End of last description line
4502 (?!\s) # Next line not starting with
4509 # Not found; not a debugger command.
4511 print_help("B<$asked> is not a debugger command.\n");
4513 } ## end elsif ($line =~ /^(\S.*)$/)
4515 # 'h' - print the summary help.
4517 print_help($summary);
4521 =head3 C<cmd_l> - list lines (command)
4523 Most of the command is taken up with transforming all the different line
4524 specification syntaxes into 'start-stop'. After that is done, the command
4525 runs a loop over C<@dbline> for the specified range of lines. It handles
4526 the printing of each line and any markers (C<==E<gt>> for current line,
4527 C<b> for break on this line, C<a> for action on this line, C<:> for this
4530 We save the last line listed in the C<$start> global for further listing
4536 my $current_line = shift;
4539 # If this is '-something', delete any spaces after the dash.
4540 $line =~ s/^-\s*$/-/;
4542 # If the line is '$something', assume this is a scalar containing a
4544 if ($line =~ /^(\$.*)/s) {
4546 # Set up for DB::eval() - evaluate in *user* context.
4550 # Ooops. Bad scalar.
4551 print($OUT "Error: $@\n"), next CMD if $@;
4553 # Good scalar. If it's a reference, find what it points to.
4555 print($OUT "Interpreted as: $1 $s\n");
4558 # Call self recursively to really do the command.
4560 } ## end if ($line =~ /^(\$.*)/s)
4562 # l name. Try to find a sub by that name.
4563 elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s) {
4564 my $s = $subname = $1;
4567 $subname =~ s/\'/::/;
4569 # Put it in this package unless it starts with ::.
4570 $subname = $package . "::" . $subname unless $subname =~ /::/;
4572 # Put it in CORE::GLOBAL if t doesn't start with :: and
4573 # it doesn't live in this package and it lives in CORE::GLOBAL.
4574 $subname = "CORE::GLOBAL::$s"
4575 if not defined &$subname
4577 and defined &{"CORE::GLOBAL::$s"};
4579 # Put leading '::' names into 'main::'.
4580 $subname = "main" . $subname if substr($subname, 0, 2) eq "::";
4582 # Get name:start-stop from find_sub, and break this up at
4584 @pieces = split (/:/, find_sub($subname) || $sub{$subname});
4586 # Pull off start-stop.
4587 $subrange = pop @pieces;
4589 # If the name contained colons, the split broke it up.
4590 # Put it back together.
4591 $file = join (':', @pieces);
4593 # If we're not in that file, switch over to it.
4594 if ($file ne $filename) {
4595 print $OUT "Switching to file '$file'.\n"
4596 unless $slave_editor;
4598 # Switch debugger's magic structures.
4599 *dbline = $main::{ '_<' . $file };
4602 } ## end if ($file ne $filename)
4604 # Subrange is 'start-stop'. If this is less than a window full,
4605 # swap it to 'start+', which will list a window from the start point.
4607 if (eval($subrange) < -$window) {
4608 $subrange =~ s/-.*/+/;
4610 # Call self recursively to list the range.
4612 &cmd_l('l', $subrange);
4613 } ## end if ($subrange)
4617 print $OUT "Subroutine $subname not found.\n";
4619 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s)
4622 elsif ($line =~ /^\s*$/) {
4623 # Compute new range to list.
4624 $incr = $window - 1;
4625 $line = $start . '-' . ($start + $incr);
4630 # l [start]+number_of_lines
4631 elsif ($line =~ /^(\d*)\+(\d*)$/) {
4632 # Don't reset start for 'l +nnn'.
4635 # Increment for list. Use window size if not specified.
4636 # (Allows 'l +' to work.)
4638 $incr = $window - 1 unless $incr;
4640 # Create a line range we'll understand, and recurse to do it.
4641 $line = $start . '-' . ($start + $incr);
4643 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/)
4645 # l start-stop or l start,stop
4646 elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/) {
4648 # Determine end point; use end of file if not specified.
4649 $end = (!defined $2) ? $max : ($4 ? $4 : $2);
4651 # Go on to the end, and then stop.
4652 $end = $max if $end > $max;
4654 # Determine start line.
4656 $i = $line if $i eq '.';
4660 # If we're running under a slave editor, force it to show the lines.
4661 if ($slave_editor) {
4662 print $OUT "\032\032$filename:$i:0\n";
4666 # We're doing it ourselves. We want to show the line and special
4668 # - the current line in execution
4669 # - whether a line is breakable or not
4670 # - whether a line has a break or not
4671 # - whether a line has an action or not
4673 for (; $i <= $end ; $i++) {
4674 # Check for breakpoints and actions.
4675 my ($stop, $action);
4676 ($stop, $action) = split (/\0/, $dbline{$i})
4679 # ==> if this is the current line in execution,
4680 # : if it's breakable.
4682 ($i == $current_line and $filename eq $filename_ini)
4684 : ($dbline[$i] + 0 ? ':' : ' ');
4686 # Add break and action indicators.
4687 $arrow .= 'b' if $stop;
4688 $arrow .= 'a' if $action;
4691 print $OUT "$i$arrow\t", $dbline[$i];
4693 # Move on to the next line. Drop out on an interrupt.
4694 $i++, last if $signal;
4695 } ## end for (; $i <= $end ; $i++)
4697 # Line the prompt up; print a newline if the last line listed
4698 # didn't have a newline.
4699 print $OUT "\n" unless $dbline[$i - 1] =~ /\n$/;
4700 } ## end else [ if ($slave_editor)
4702 # Save the point we last listed to in case another relative 'l'
4703 # command is desired. Don't let it run off the end.
4705 $start = $max if $start > $max;
4706 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/)
4709 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
4711 To list breakpoints, the command has to look determine where all of them are
4712 first. It starts a C<%had_breakpoints>, which tells us what all files have
4713 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
4714 magic source and breakpoint data structures) to the file, and then look
4715 through C<%dbline> for lines with breakpoints and/or actions, listing them
4716 out. We look through C<%postponed> not-yet-compiled subroutines that have
4717 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
4718 that have breakpoints.
4720 Watchpoints are simpler: we just list the entries in C<@to_watch>.
4727 # If no argument, list everything. Pre-5.8.0 version always lists
4729 my $arg = shift || 'abw';
4730 $arg = 'abw' unless $CommandSet eq '580'; # sigh...
4732 # See what is wanted.
4733 my $action_wanted = ($arg =~ /a/) ? 1 : 0;
4734 my $break_wanted = ($arg =~ /b/) ? 1 : 0;
4735 my $watch_wanted = ($arg =~ /w/) ? 1 : 0;
4737 # Breaks and actions are found together, so we look in the same place
4739 if ($break_wanted or $action_wanted) {
4740 # Look in all the files with breakpoints...
4741 for my $file (keys %had_breakpoints) {
4742 # Temporary switch to this file.
4743 local *dbline = $main::{ '_<' . $file };
4745 # Set up to look through the whole file.
4747 my $was; # Flag: did we print something
4750 # For each line in the file ...
4751 for ($i = 1 ; $i <= $max ; $i++) {
4752 # We've got something on this line.
4753 if (defined $dbline{$i}) {
4754 # Print the header if we haven't.
4755 print $OUT "$file:\n" unless $was++;
4758 print $OUT " $i:\t", $dbline[$i];
4760 # Pull out the condition and the action.
4761 ($stop, $action) = split (/\0/, $dbline{$i});
4763 # Print the break if there is one and it's wanted.
4764 print $OUT " break if (", $stop, ")\n"
4768 # Print the action if there is one and it's wanted.
4769 print $OUT " action: ", $action, "\n"
4773 # Quit if the user hit interrupt.
4775 } ## end if (defined $dbline{$i...
4776 } ## end for ($i = 1 ; $i <= $max...
4777 } ## end for my $file (keys %had_breakpoints)
4778 } ## end if ($break_wanted or $action_wanted)
4780 # Look for breaks in not-yet-compiled subs:
4781 if (%postponed and $break_wanted) {
4782 print $OUT "Postponed breakpoints in subroutines:\n";
4784 for $subname (keys %postponed) {
4785 print $OUT " $subname\t$postponed{$subname}\n";
4788 } ## end if (%postponed and $break_wanted)
4790 # Find files that have not-yet-loaded breaks:
4791 my @have = map { # Combined keys
4792 keys %{ $postponed_file{$_} }
4793 } keys %postponed_file;
4795 # If there are any, list them.
4796 if (@have and ($break_wanted or $action_wanted)) {
4797 print $OUT "Postponed breakpoints in files:\n";
4800 for $file (keys %postponed_file) {
4801 my $db = $postponed_file{$file};
4802 print $OUT " $file:\n";
4803 for $line (sort { $a <=> $b } keys %$db) {
4804 print $OUT " $line:\n";
4805 my ($stop, $action) = split (/\0/, $$db{$line});
4806 print $OUT " break if (", $stop, ")\n"
4809 print $OUT " action: ", $action, "\n"
4813 } ## end for $line (sort { $a <=>...
4815 } ## end for $file (keys %postponed_file)
4816 } ## end if (@have and ($break_wanted...
4817 if (%break_on_load and $break_wanted) {
4818 print $OUT "Breakpoints on load:\n";
4820 for $file (keys %break_on_load) {
4821 print $OUT " $file\n";
4824 } ## end if (%break_on_load and...
4825 if ($watch_wanted) {
4827 print $OUT "Watch-expressions:\n" if @to_watch;
4828 for my $expr (@to_watch) {
4829 print $OUT " $expr\n";
4832 } ## end if ($trace & 2)
4833 } ## end if ($watch_wanted)
4836 =head3 C<cmd_M> - list modules (command)
4838 Just call C<list_modules>.
4846 =head3 C<cmd_o> - options (command)
4848 If this is just C<o> by itself, we list the current settings via
4849 C<dump_option>. If there's a nonblank value following it, we pass that on to
4850 C<parse_options> for processing.
4856 my $opt = shift || ''; # opt[=val]
4858 # Nonblank. Try to parse and process.
4859 if ($opt =~ /^(\S.*)/) {
4863 # Blank. List the current option settings.
4871 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
4873 Advises the user that the O command has been renamed.
4878 print $OUT "The old O command is now the o command.\n"; # hint
4879 print $OUT "Use 'h' to get current command help synopsis or\n"; #
4880 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
4883 =head3 C<cmd_v> - view window (command)
4885 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
4886 move back a few lines to list the selected line in context. Uses C<cmd_l>
4887 to do the actual listing after figuting out the range of line to request.
4895 # Extract the line to list around. (Astute readers will have noted that
4896 # this pattern will match whether or not a numeric line is specified,
4897 # which means that we'll always enter this loop (though a non-numeric
4898 # argument results in no action at all)).
4899 if ($line =~ /^(\d*)$/) {
4900 # Total number of lines to list (a windowful).
4901 $incr = $window - 1;
4903 # Set the start to the argument given (if there was one).
4906 # Back up by the context amount.
4909 # Put together a linespec that cmd_l will like.
4910 $line = $start . '-' . ($start + $incr);
4914 } ## end if ($line =~ /^(\d*)$/)
4917 =head3 C<cmd_w> - add a watch expression (command)
4919 The 5.8 version of this command adds a watch expression if one is specified;
4920 it does nothing if entered with no operands.
4922 We extract the expression, save it, evaluate it in the user's context, and
4923 save the value. We'll re-evaluate it each time the debugger passes a line,
4924 and will stop (see the code at the top of the command loop) if the value
4925 of any of the expressions changes.
4932 # Null expression if no arguments.
4933 my $expr = shift || '';
4935 # If expression is not null ...
4936 if ($expr =~ /^(\S.*)/) {
4938 push @to_watch, $expr;
4940 # Parameterize DB::eval and call it to get the expression's value
4941 # in the user's context. This version can handle expressions which
4942 # return a list value.
4944 my ($val) = join(' ', &eval);
4945 $val = (defined $val) ? "'$val'" : 'undef';
4947 # Save the current value of the expression.
4948 push @old_watch, $val;
4950 # We are now watching expressions.
4952 } ## end if ($expr =~ /^(\S.*)/)
4954 # You have to give one to get one.
4957 "Adding a watch-expression requires an expression\n"; # hint
4961 =head3 C<cmd_W> - delete watch expressions (command)
4963 This command accepts either a watch expression to be removed from the list
4964 of watch expressions, or C<*> to delete them all.
4966 If C<*> is specified, we simply empty the watch expression list and the
4967 watch expression value list. We also turn off the bit that says we've got
4970 If an expression (or partial expression) is specified, we pattern-match
4971 through the expressions and remove the ones that match. We also discard
4972 the corresponding values. If no watch expressions are left, we turn off
4973 the 'watching expressions' bit.
4979 my $expr = shift || '';
4986 print $OUT "Deleting all watch expressions ...\n";
4989 @to_watch = @old_watch = ();
4992 # Delete one of them.
4993 elsif ($expr =~ /^(\S.*)/) {
4994 # Where we are in the list.
4997 # For each expression ...
4998 foreach (@to_watch) {
4999 my $val = $to_watch[$i_cnt];
5001 # Does this one match the command argument?
5002 if ($val eq $expr) { # =~ m/^\Q$i$/) {
5004 splice(@to_watch, $i_cnt, 1);
5005 # We ought to kill the value too, oughtn't we?
5006 # But we don't. XXX This is a bug.
5009 } ## end foreach (@to_watch)
5011 # We probably should see if they're all gone. But we don't.
5012 # No bug shows up for this because the 'check watch expressions'
5013 # code iterates over the @to_watch array. Since it's empty, nothing
5015 } ## end elsif ($expr =~ /^(\S.*)/)
5017 # No command arguments entered.
5020 "Deleting a watch-expression requires an expression, or '*' for all\n"
5025 ### END of the API section
5027 =head1 SUPPORT ROUTINES
5029 These are general support routines that are used in a number of places
5030 throughout the debugger.
5034 save() saves the user's versions of globals that would mess us up in C<@saved>,
5035 and installs the versions we like better.
5040 # Save eval failure, command failure, extended OS error, output field
5041 # separator, input record separator, output record separator and
5042 # the warning setting.
5043 @saved = ($@, $!, $^E, $,, $/, $\, $^W);
5045 $, = ""; # output field separator is null string
5046 $/ = "\n"; # input record separator is newline
5047 $\ = ""; # output record separator is null string
5048 $^W = 0; # warnings are off
5051 =head2 C<print_lineinfo> - show where we are now
5053 print_lineinfo prints whatever it is that it is handed; it prints it to the
5054 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
5055 us to feed line information to a slave editor without messing up the
5060 sub print_lineinfo {
5061 # Make the terminal sensible if we're not the primary debugger.
5062 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
5066 } ## end sub print_lineinfo
5068 =head2 C<postponed_sub>
5070 Handles setting postponed breakpoints in subroutines once they're compiled.
5071 For breakpoints, we use C<DB::find_sub> to locate the source file and line
5072 range for the subroutine, then mark the file as having a breakpoint,
5073 temporarily switch the C<*dbline> glob over to the source file, and then
5074 search the given range of lines to find a breakable line. If we find one,
5075 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
5079 # The following takes its argument via $evalarg to preserve current @_
5082 # Get the subroutine name.
5083 my $subname = shift;
5085 # If this is a 'break +<n> if <condition>' ...
5086 if ($postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s//) {
5087 # If there's no offset, use '+0'.
5088 my $offset = $1 || 0;
5090 # find_sub's value is 'fullpath-filename:start-stop'. It's
5091 # possible that the filename might have colons in it too.
5092 my ($file, $i) = (find_sub($subname) =~ /^(.*):(\d+)-.*$/);
5094 # We got the start line. Add the offset '+<n>' from
5095 # $postponed{subname}.
5098 # Switch to the file this sub is in, temporarily.
5099 local *dbline = $main::{ '_<' . $file };
5101 # No warnings, please.
5102 local $^W = 0; # != 0 is magical below
5104 # This file's got a breakpoint in it.
5105 $had_breakpoints{$file} |= 1;
5107 # Last line in file.
5110 # Search forward until we hit a breakable line or get to
5111 # the end of the file.
5112 ++$i until $dbline[$i] != 0 or $i >= $max;
5114 # Copy the breakpoint in and delete it from %postponed.
5115 $dbline{$i} = delete $postponed{$subname};
5118 # find_sub didn't find the sub.
5121 print $OUT "Subroutine $subname not found.\n";
5124 } ## end if ($postponed{$subname...
5125 elsif ($postponed{$subname} eq 'compile') { $signal = 1 }
5127 #print $OUT "In postponed_sub for `$subname'.\n";
5128 } ## end sub postponed_sub
5132 Called after each required file is compiled, but before it is executed;
5133 also called if the name of a just-compiled subroutine is a key of
5134 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
5135 etc.) into the just-compiled code.
5137 If this is a C<require>'d file, the incoming parameter is the glob
5138 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
5140 If it's a subroutine, the incoming parameter is the subroutine name.
5145 # If there's a break, process it.
5146 if ($ImmediateStop) {
5147 # Right, we've stopped. Turn it off.
5150 # Enter the command loop when DB::DB gets called.
5154 # If this is a subroutine, let postponed_sub() deal with it.
5155 return &postponed_sub unless ref \$_[0] eq 'GLOB';
5157 # Not a subroutine. Deal with the file.
5158 local *dbline = shift;
5159 my $filename = $dbline;
5160 $filename =~ s/^_<//;
5162 $signal = 1, print $OUT "'$filename' loaded...\n"
5163 if $break_on_load{$filename};
5164 print_lineinfo(' ' x $stack_depth, "Package $filename.\n") if $frame;
5166 # Do we have any breakpoints to put in this file?
5167 return unless $postponed_file{$filename};
5169 # Yes. Mark this file as having breakpoints.
5170 $had_breakpoints{$filename} |= 1;
5172 # "Cannot be done: unsufficient magic" - we can't just put the
5173 # breakpoints saved in %postponed_file into %dbline by assigning
5174 # the whole hash; we have to do it one item at a time for the
5175 # breakpoints to be set properly.
5176 #%dbline = %{$postponed_file{$filename}};
5178 # Set the breakpoints, one at a time.
5181 for $key (keys %{ $postponed_file{$filename} }) {
5182 # Stash the saved breakpoint into the current file's magic line array.
5183 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
5186 # This file's been compiled; discard the stored breakpoints.
5187 delete $postponed_file{$filename};
5189 } ## end sub postponed
5193 C<dumpit> is the debugger's wrapper around dumpvar.pl.
5195 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
5196 a reference to a variable (the thing to be dumped) as its input.
5198 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
5199 the currently-selected filehandle, thank you very much). The current
5200 values of the package globals C<$single> and C<$trace> are backed up in
5201 lexicals, and they are turned off (this keeps the debugger from trying
5202 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
5203 preserve its current value and it is set to zero to prevent entry/exit
5204 messages from printing, and C<$doret> is localized as well and set to -2 to
5205 prevent return values from being shown.
5207 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
5208 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
5209 installed version in @INC, yours will be used instead. Possible security
5212 It then checks to see if the subroutine C<main::dumpValue> is now defined
5213 (it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
5214 localizes the globals necessary for things to be sane when C<main::dumpValue()>
5215 is called, and picks up the variable to be dumped from the parameter list.
5217 It checks the package global C<%options> to see if there's a C<dumpDepth>
5218 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
5219 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
5220 structure: -1 means dump everything.
5222 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
5225 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
5226 and we then return to the caller.
5231 # Save the current output filehandle and switch to the one
5232 # passed in as the first parameter.
5233 local ($savout) = select(shift);
5235 # Save current settings of $single and $trace, and then turn them off.
5236 my $osingle = $single;
5237 my $otrace = $trace;
5238 $single = $trace = 0;
5240 # XXX Okay, what do $frame and $doret do, again?
5244 # Load dumpvar.pl unless we've already got the sub we need from it.
5245 unless (defined &main::dumpValue) {
5249 # If the load succeeded (or we already had dumpvalue()), go ahead
5251 if (defined &main::dumpValue) {
5256 my $maxdepth = shift || $option{dumpDepth};
5257 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
5258 &main::dumpValue($v, $maxdepth);
5259 } ## end if (defined &main::dumpValue)
5261 # Oops, couldn't load dumpvar.pl.
5264 print $OUT "dumpvar.pl not available.\n";
5267 # Reset $single and $trace to their old values.
5271 # Restore the old filehandle.
5275 =head2 C<print_trace>
5277 C<print_trace>'s job is to print a stack trace. It does this via the
5278 C<dump_trace> routine, which actually does all the ferreting-out of the
5279 stack trace data. C<print_trace> takes care of formatting it nicely and
5280 printing it to the proper filehandle.
5286 =item * The filehandle to print to.
5288 =item * How many frames to skip before starting trace.
5290 =item * How many frames to print.
5292 =item * A flag: if true, print a "short" trace without filenames, line numbers, or arguments
5296 The original comment below seems to be noting that the traceback may not be
5297 correct if this routine is called in a tied method.
5301 # Tied method do not create a context, so may get wrong message:
5306 # If this is going to a slave editor, but we're not the primary
5307 # debugger, reset it first.
5309 if $fh eq $LINEINFO # slave editor
5310 and $LINEINFO eq $OUT # normal output
5311 and $term_pid != $$; # not the primary
5313 # Collect the actual trace information to be formatted.
5314 # This is an array of hashes of subroutine call info.
5315 my @sub = dump_trace($_[0] + 1, $_[1]);
5317 # Grab the "short report" flag from @_.
5318 my $short = $_[2]; # Print short report, next one for sub name
5320 # Run through the traceback info, format it, and print it.
5322 for ($i = 0 ; $i <= $#sub ; $i++) {
5323 # Drop out if the user has lost interest and hit control-C.
5326 # Set the separator so arrys print nice.
5329 # Grab and stringify the arguments if they are there.
5331 defined $sub[$i]{args}
5332 ? "(@{ $sub[$i]{args} })"
5334 # Shorten them up if $maxtrace says they're too long.
5335 $args = (substr $args, 0, $maxtrace - 3) . '...'
5336 if length $args > $maxtrace;
5338 # Get the file name.
5339 my $file = $sub[$i]{file};
5341 # Put in a filename header if short is off.
5342 $file = $file eq '-e' ? $file : "file `$file'" unless $short;
5344 # Get the actual sub's name, and shorten to $maxtrace's requirement.
5346 $s = (substr $s, 0, $maxtrace - 3) . '...' if length $s > $maxtrace;
5348 # Short report uses trimmed file and sub names.
5350 my $sub = @_ >= 4 ? $_[3] : $s;
5352 "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
5353 } ## end if ($short)
5355 # Non-short report includes full names.
5357 print $fh "$sub[$i]{context} = $s$args" . " called from $file" .
5358 " line $sub[$i]{line}\n";
5360 } ## end for ($i = 0 ; $i <= $#sub...
5361 } ## end sub print_trace
5363 =head2 dump_trace(skip[,count])
5365 Actually collect the traceback information available via C<caller()>. It does
5366 some filtering and cleanup of the data, but mostly it just collects it to
5367 make C<print_trace()>'s job easier.
5369 C<skip> defines the number of stack frames to be skipped, working backwards
5370 from the most current. C<count> determines the total number of frames to
5371 be returned; all of them (well, the first 10^9) are returned if C<count>
5374 This routine returns a list of hashes, from most-recent to least-recent
5375 stack frame. Each has the following keys and values:
5379 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
5381 =item * C<sub> - subroutine name, or C<eval> information
5383 =item * C<args> - undef, or a reference to an array of arguments
5385 =item * C<file> - the file in which this item was defined (if any)
5387 =item * C<line> - the line on which it was defined
5395 # How many levels to skip.
5398 # How many levels to show. (1e9 is a cheap way of saying "all of them";
5399 # it's unlikely that we'll have more than a billion stack frames. If you
5400 # do, you've got an awfully big machine...)
5401 my $count = shift || 1e9;
5403 # We increment skip because caller(1) is the first level *back* from
5404 # the current one. Add $skip to the count of frames so we have a
5405 # simple stop criterion, counting from $skip to $count+$skip.
5409 # These variables are used to capture output from caller();
5410 my ($p, $file, $line, $sub, $h, $context);
5412 my ($e, $r, @a, @sub, $args);
5414 # XXX Okay... why'd we do that?
5415 my $nothard = not $frame & 8;
5418 # Do not want to trace this.
5419 my $otrace = $trace;
5422 # Start out at the skip count.
5423 # If we haven't reached the number of frames requested, and caller() is
5424 # still returning something, stay in the loop. (If we pass the requested
5425 # number of stack frames, or we run out - caller() returns nothing - we
5427 # Up the stack frame index to go back one more level each time.
5431 and ($p, $file, $line, $sub, $h, $context, $e, $r) = caller($i) ;
5436 # Go through the arguments and save them for later.
5440 if (not defined $arg) { # undefined parameter
5444 elsif ($nothard and tied $arg) { # tied parameter
5447 elsif ($nothard and $type = ref $arg) { # reference
5448 push @a, "ref($type)";
5450 else { # can be stringified
5452 "$arg"; # Safe to stringify now - should not call f().
5454 # Backslash any single-quotes or backslashes.
5457 # Single-quote it unless it's a number or a colon-separated
5460 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
5462 # Turn high-bit characters into meta-whatever.
5463 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
5465 # Turn control characters into ^-whatever.
5466 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
5469 } ## end else [ if (not defined $arg)
5470 } ## end for $arg (@args)
5472 # If context is true, this is array (@)context.
5473 # If context is false, this is scalar ($) context.
5474 # If neither, context isn't defined. (This is apparently a 'can't
5476 $context = $context ? '@' : (defined $context ? "\$" : '.');
5478 # if the sub has args ($h true), make an anonymous array of the
5480 $args = $h ? [@a] : undef;
5482 # remove trailing newline-whitespace-semicolon-end of line sequence
5483 # from the eval text, if any.
5484 $e =~ s/\n\s*\;\s*\Z// if $e;
5486 # Escape backslashed single-quotes again if necessary.
5487 $e =~ s/([\\\'])/\\$1/g if $e;
5489 # if the require flag is true, the eval text is from a require.
5491 $sub = "require '$e'";
5493 # if it's false, the eval text is really from an eval.
5494 elsif (defined $r) {
5498 # If the sub is '(eval)', this is a block eval, meaning we don't
5499 # know what the eval'ed text actually was.
5500 elsif ($sub eq '(eval)') {
5501 $sub = "eval {...}";
5504 # Stick the collected information into @sub as an anonymous hash.
5508 context => $context,
5516 # Stop processing frames if the user hit control-C.
5518 } ## end for ($i = $skip ; $i < ...
5520 # Restore the trace value again.
5523 } ## end sub dump_trace
5527 C<action()> takes input provided as the argument to an add-action command,
5528 either pre- or post-, and makes sure it's a complete command. It doesn't do
5529 any fancy parsing; it just keeps reading input until it gets a string
5530 without a traiing backslash.
5537 while ($action =~ s/\\$//) {
5538 # We have a backslash on the end. Read more.
5540 } ## end while ($action =~ s/\\$//)
5542 # Return the assembled action.
5548 This routine mostly just packages up a regular expression to be used
5549 to check that the thing it's being matched against has properly-matched
5552 Of note is the definition of the $balanced_brace_re global via ||=, which
5553 speeds things up by only creating the qr//'ed expression once; if it's
5554 already defined, we don't try to define it again. A speed hack.
5560 # I hate using globals!
5561 $balanced_brace_re ||= qr{
5564 (?> [^{}] + ) # Non-parens without backtracking
5566 (??{ $balanced_brace_re }) # Group with matching parens
5570 return $_[0] !~ m/$balanced_brace_re/;
5571 } ## end sub unbalanced
5575 C<gets()> is a primitive (very primitive) routine to read continuations.
5576 It was devised for reading continuations for actions.
5577 it just reads more input with X<C<readline()>> and returns it.
5582 &readline("cont: ");
5585 =head2 C<DB::system()> - handle calls to<system()> without messing up the debugger
5587 The C<system()> function assumes that it can just go ahead and use STDIN and
5588 STDOUT, but under the debugger, we want it to use the debugger's input and
5591 C<DB::system()> socks away the program's STDIN and STDOUT, and then substitutes
5592 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
5593 and then puts everything back again.
5599 # We save, change, then restore STDIN and STDOUT to avoid fork() since
5600 # some non-Unix systems can do system() but have problems with fork().
5601 open(SAVEIN, "<&STDIN") || &warn("Can't save STDIN");
5602 open(SAVEOUT, ">&STDOUT") || &warn("Can't save STDOUT");
5603 open(STDIN, "<&IN") || &warn("Can't redirect STDIN");
5604 open(STDOUT, ">&OUT") || &warn("Can't redirect STDOUT");
5606 # XXX: using csh or tcsh destroys sigint retvals!
5608 open(STDIN, "<&SAVEIN") || &warn("Can't restore STDIN");
5609 open(STDOUT, ">&SAVEOUT") || &warn("Can't restore STDOUT");
5613 # most of the $? crud was coping with broken cshisms
5615 &warn("(Command exited ", ($? >> 8), ")\n");
5619 "(Command died of SIG#",
5621 (($? & 128) ? " -- core dumped" : ""),
5630 =head1 TTY MANAGEMENT
5632 The subs here do some of the terminal management for multiple debuggers.
5636 Top-level function called when we want to set up a new terminal for use
5639 If the C<noTTY> debugger option was set, we'll either use the terminal
5640 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
5641 to find one. If we're a forked debugger, we call C<resetterm> to try to
5642 get a whole new terminal if we can.
5644 In either case, we set up the terminal next. If the C<ReadLine> option was
5645 true, we'll get a C<Term::ReadLine> object for the current terminal and save
5646 the appropriate attributes. We then
5651 # Load Term::Readline, but quietly; don't debug it and don't trace it.
5654 eval { require Term::ReadLine } or die $@;
5656 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
5659 my ($i, $o) = split $tty, /,/;
5660 $o = $i unless defined $o;
5661 open(IN, "<$i") or die "Cannot open TTY `$i' for read: $!";
5662 open(OUT, ">$o") or die "Cannot open TTY `$o' for write: $!";
5665 my $sel = select($OUT);
5670 # We don't have a TTY - try to find one via Term::Rendezvous.
5672 eval "require Term::Rendezvous;" or die;
5673 # See if we have anything to pass to Term::Rendezvous.
5674 # Use /tmp/perldbtty$$ if not.
5675 my $rv = $ENV{PERLDB_NOTTY} || "/tmp/perldbtty$$";
5677 # Rendezvous and get the filehandles.
5678 my $term_rv = new Term::Rendezvous $rv;
5680 $OUT = $term_rv->OUT;
5681 } ## end else [ if ($tty)
5682 } ## end if ($notty)
5685 # We're a daughter debugger. Try to fork off another TTY.
5686 if ($term_pid eq '-1') { # In a TTY with another debugger
5690 # If we shouldn't use Term::ReadLine, don't.
5692 $term = new Term::ReadLine::Stub 'perldb', $IN, $OUT;
5695 # We're using Term::ReadLine. Get all the attributes for this terminal.
5697 $term = new Term::ReadLine 'perldb', $IN, $OUT;
5699 $rl_attribs = $term->Attribs;
5700 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
5701 if defined $rl_attribs->{basic_word_break_characters}
5702 and index($rl_attribs->{basic_word_break_characters}, ":") == -1;
5703 $rl_attribs->{special_prefixes} = '$@&%';
5704 $rl_attribs->{completer_word_break_characters} .= '$@&%';
5705 $rl_attribs->{completion_function} = \&db_complete;
5706 } ## end else [ if (!$rl)
5708 # Set up the LINEINFO filehandle.
5709 $LINEINFO = $OUT unless defined $LINEINFO;
5710 $lineinfo = $console unless defined $lineinfo;
5714 if ($term->Features->{setHistory} and "@hist" ne "?") {
5715 $term->SetHistory(@hist);
5718 # XXX Ornaments are turned on unconditionally, which is not
5719 # always a good thing.
5720 ornaments($ornaments) if defined $ornaments;
5722 } ## end sub setterm
5724 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
5726 When the process being debugged forks, or the process invokes a command
5727 via C<system()> which starts a new debugger, we need to be able to get a new
5728 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
5729 fight over the terminal, and you can never quite be sure who's going to get the
5730 input you're typing.
5732 C<get_fork_TTY> is a glob-aliased function which calls the real function that
5733 is tasked with doing all the necessary operating system mojo to get a new
5734 TTY (and probably another window) and to direct the new debugger to read and
5737 The debugger provides C<get_fork_TTY> functions which work for X Windows and
5738 OS/2. Other systems are not supported. You are encouraged to write
5739 C<get_fork_TTY> functions which work for I<your> platform and contribute them.
5741 =head3 C<xterm_get_fork_TTY>
5743 This function provides the C<get_fork_TTY> function for X windows. If a
5744 program running under the debugger forks, a new <xterm> window is opened and
5745 the subsidiary debugger is directed there.
5747 The C<open()> call is of particular note here. We have the new C<xterm>
5748 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
5749 command (which prints the device name of the TTY we'll want to use for input
5750 and output to STDOUT, then C<sleep> for a very long time, routing this output
5751 to file number 3. This way we can simply read from the <XT> filehandle (which
5752 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
5754 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
5759 sub xterm_get_fork_TTY {
5760 (my $name = $0) =~ s,^.*[/\\],,s;
5762 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
5765 # Get the output from 'tty' and clean it up a little.
5769 $pidprompt = ''; # Shown anyway in titlebar
5771 # There's our new TTY.
5773 } ## end sub xterm_get_fork_TTY
5775 =head3 C<os2_get_fork_TTY>
5777 XXX It behooves an OS/2 expert to write the necessary documentation for this!
5781 # This example function resets $IN, $OUT itself
5782 sub os2_get_fork_TTY {
5783 local $^F = 40; # XXXX Fixme!
5785 my ($in1, $out1, $in2, $out2);
5787 # Having -d in PERL5OPT would lead to a disaster...
5788 local $ENV{PERL5OPT} = $ENV{PERL5OPT} if $ENV{PERL5OPT};
5789 $ENV{PERL5OPT} =~ s/(?:^|(?<=\s))-d\b// if $ENV{PERL5OPT};
5790 $ENV{PERL5OPT} =~ s/(?:^|(?<=\s))-d\B/-/ if $ENV{PERL5OPT};
5791 print $OUT "Making kid PERL5OPT->`$ENV{PERL5OPT}'.\n" if $ENV{PERL5OPT};
5792 local $ENV{PERL5LIB} = $ENV{PERL5LIB} ? $ENV{PERL5LIB} : $ENV{PERLLIB};
5793 $ENV{PERL5LIB} = '' unless defined $ENV{PERL5LIB};
5794 $ENV{PERL5LIB} = join ';', @ini_INC, split /;/, $ENV{PERL5LIB};
5795 (my $name = $0) =~ s,^.*[/\\],,s;
5800 and pipe $in2, $out2
5802 # system P_SESSION will fail if there is another process
5803 # in the same session with a "dependent" asynchronous child session.
5805 $rl, fileno $in1, fileno $out2,
5806 "Daughter Perl debugger $pids $name"
5809 ($kpid = CORE::system 4, $^X, '-we',
5810 <<'ES', @args) >= 0 # P_SESSION
5811 END {sleep 5 unless $loaded}
5812 BEGIN {open STDIN, '</dev/con' or warn "reopen stdin: $!"}
5815 my ($rl, $in) = (shift, shift); # Read from $in and pass through
5817 system P_NOWAIT, $^X, '-we', <<EOS or die "Cannot start a grandkid";
5818 open IN, '<&=$in' or die "open <&=$in: \$!";
5819 \$| = 1; print while sysread IN, \$_, 1<<16;
5823 open OUT, ">&=$out" or die "Cannot open &=$out for writing: $!";
5825 require Term::ReadKey if $rl;
5826 Term::ReadKey::ReadMode(4) if $rl; # Nodelay on kbd. Pipe is automatically nodelay...
5827 print while sysread STDIN, $_, 1<<($rl ? 16 : 0);
5829 or warn "system P_SESSION: $!, $^E" and 0
5835 $pidprompt = ''; # Shown anyway in titlebar
5836 reset_IN_OUT($in2, $out1);
5838 return ''; # Indicate that reset_IN_OUT is called
5839 } ## end if (pipe $in1, $out1 and...
5841 } ## end sub os2_get_fork_TTY
5843 =head2 C<create_IN_OUT($flags)>
5845 Create a new pair of filehandles, pointing to a new TTY. If impossible,
5846 try to diagnose why.
5852 =item * 1 - Don't know how to create a new TTY.
5854 =item * 2 - Debugger has forked, but we can't get a new TTY.
5856 =item * 4 - standard debugger startup is happening.
5862 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
5864 # If we know how to get a new TTY, do it! $in will have
5865 # the TTY name if get_fork_TTY works.
5866 my $in = &get_fork_TTY if defined &get_fork_TTY;
5868 # It used to be that
5869 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
5871 if (not defined $in) {
5874 # We don't know how.
5875 print_help(<<EOP) if $why == 1;
5876 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
5880 print_help(<<EOP) if $why == 2;
5881 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
5882 This may be an asynchronous session, so the parent debugger may be active.
5885 # Note that both debuggers are fighting over the same input.
5886 print_help(<<EOP) if $why != 4;
5887 Since two debuggers fight for the same TTY, input is severely entangled.
5891 I know how to switch the output to a different window in xterms
5892 and OS/2 consoles only. For a manual switch, put the name of the created I<TTY>
5893 in B<\$DB::fork_TTY>, or define a function B<DB::get_fork_TTY()> returning this.
5895 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
5896 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
5899 } ## end if (not defined $in)
5904 $console = ''; # Indicate no need to open-from-the-console
5907 } ## end sub create_IN_OUT
5911 Handles rejiggering the prompt when we've forked off a new debugger.
5913 If the new debugger happened because of a C<system()> that invoked a
5914 program under the debugger, the arrow between the old pid and the new
5915 in the prompt has I<two> dashes instead of one.
5917 We take the current list of pids and add this one to the end. If there
5918 isn't any list yet, we make one up out of the initial pid associated with
5919 the terminal and our new pid, sticking an arrow (either one-dashed or
5920 two dashed) in between them.
5922 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
5923 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
5928 sub resetterm { # We forked, so we need a different TTY
5930 # Needs to be passed to create_IN_OUT() as well.
5933 # resetterm(2): got in here because of a system() starting a debugger.
5934 # resetterm(1): just forked.
5935 my $systemed = $in > 1 ? '-' : '';
5937 # If there's already a list of pids, add this to the end.
5939 $pids =~ s/\]/$systemed->$$]/;
5942 # No pid list. Time to make one.
5944 $pids = "[$term_pid->$$]";
5947 # The prompt we're going to be using for this debugger.
5950 # We now 0wnz this terminal.
5953 # Just return if we're not supposed to try to create a new TTY.
5954 return unless $CreateTTY & $in;
5956 # Try to create a new IN/OUT pair.
5958 } ## end sub resetterm
5962 First, we handle stuff in the typeahead buffer. If there is any, we shift off
5963 the next line, print a message saying we got it, add it to the terminal
5964 history (if possible), and return it.
5966 If there's nothing in the typeahead buffer, check the command filehandle stack.
5967 If there are any filehandles there, read from the last one, and return the line
5968 if we got one. If not, we pop the filehandle off and close it, and try the
5969 next one up the stack.
5971 If we've emptied the filehandle stack, we check to see if we've got a socket
5972 open, and we read that and return it if we do. If we don't, we just call the
5973 core C<readline()> and return its value.
5979 # Localize to prevent it from being smashed in the program being debugged.
5982 # Pull a line out of the typeahead if there's stuff there.
5984 # How many lines left.
5985 my $left = @typeahead;
5987 # Get the next line.
5988 my $got = shift @typeahead;
5990 # Print a message saying we got input from the typeahead.
5992 print $OUT "auto(-$left)", shift, $got, "\n";
5994 # Add it to the terminal history (if possible).
5995 $term->AddHistory($got)
5997 and defined $term->Features->{addHistory};
5999 } ## end if (@typeahead)
6001 # We really need to read some input. Turn off entry/exit trace and
6002 # return value printing.
6006 # If there are stacked filehandles to read from ...
6008 # Read from the last one in the stack.
6009 my $line = CORE::readline($cmdfhs[-1]);
6010 # If we got a line ...
6012 ? (print $OUT ">> $line" and return $line) # Echo and return
6013 : close pop @cmdfhs; # Pop and close
6014 } ## end while (@cmdfhs)
6016 # Nothing on the filehandle stack. Socket?
6017 if (ref $OUT and UNIVERSAL::isa($OUT, 'IO::Socket::INET')) {
6018 # Send anyting we have to send.
6019 $OUT->write(join ('', @_));
6021 # Receive anything there is to receive.
6023 $IN->recv($stuff, 2048); # XXX "what's wrong with sysread?"
6024 # XXX Don't know. You tell me.
6028 } ## end if (ref $OUT and UNIVERSAL::isa...
6030 # No socket. Just read from the terminal.
6032 $term->readline(@_);
6034 } ## end sub readline
6036 =head1 OPTIONS SUPPORT ROUTINES
6038 These routines handle listing and setting option values.
6040 =head2 C<dump_option> - list the current value of an option setting
6042 This routine uses C<option_val> to look up the value for an option.
6043 It cleans up escaped single-quotes and then displays the option and
6049 my ($opt, $val) = @_;
6050 $val = option_val($opt, 'N/A');
6051 $val =~ s/([\\\'])/\\$1/g;
6052 printf $OUT "%20s = '%s'\n", $opt, $val;
6053 } ## end sub dump_option
6055 =head2 C<option_val> - find the current value of an option
6057 This can't just be a simple hash lookup because of the indirect way that
6058 the option values are stored. Some are retrieved by calling a subroutine,
6059 some are just variables.
6061 You must supply a default value to be used in case the option isn't set.
6066 my ($opt, $default) = @_;
6069 # Does this option exist, and is it a variable?
6070 # If so, retrieve the value via the value in %optionVars.
6071 if ( defined $optionVars{$opt}
6072 and defined ${ $optionVars{$opt} }) {
6073 $val = ${ $optionVars{$opt} };
6076 # Does this option exist, and it's a subroutine?
6077 # If so, call the subroutine via the ref in %optionAction
6078 # and capture the value.
6079 elsif ( defined $optionAction{$opt}
6080 and defined &{ $optionAction{$opt} }) {
6081 $val = &{ $optionAction{$opt} }();
6084 # If there's an action or variable for the supplied option,
6085 # but no value was set, use the default.
6086 elsif (defined $optionAction{$opt} and not defined $option{$opt}
6087 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} })
6092 # Otherwise, do the simple hash lookup.
6094 $val = $option{$opt};
6097 # If the value isn't defined, use the default.
6098 # Then return whatever the value is.
6099 $val = $default unless defined $val;
6101 } ## end sub option_val
6103 =head2 C<parse_options>
6105 Handles the parsing and execution of option setting/displaying commands.
6107 An option entered by itself is assumed to be 'set me to 1' (the default value)
6108 if the option is a boolean one. If not, the user is prompted to enter a valid
6109 value or to query the current value (via 'option? ').
6111 If 'option=value' is entered, we try to extract a quoted string from the
6112 value (if it is quoted). If it's not, we just use the whole value as-is.
6114 We load any modules required to service this option, and then we set it: if
6115 it just gets stuck in a variable, we do that; if there's a subroutine to
6116 handle setting the option, we call that.
6118 Finally, if we're running in interactive mode, we display the effect of the
6119 user's command back to the terminal, skipping this if we're setting things
6120 during initialization.
6128 # These options need a value. Don't allow them to be clobbered by accident.
6129 my %opt_needs_val = map { ($_ => 1) } qw{
6130 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
6131 pager quote ReadLine recallCommand RemotePort ShellBang TTY
6137 # Clean off excess leading whitespace.
6140 # Options are always all word characters, followed by a non-word
6142 s/^(\w+)(\W?)// or print($OUT "Invalid option `$_'\n"), last;
6143 my ($opt, $sep) = ($1, $2);
6147 # '?' as separator means query, but must have whitespace after it.
6149 print($OUT "Option query `$opt?' followed by non-space `$_'\n"),
6153 #&dump_option($opt);
6154 } ## end if ("?" eq $sep)
6156 # Separator is whitespace (or just a carriage return).
6157 # They're going for a default, which we assume is 1.
6158 elsif ($sep !~ /\S/) {
6160 $val = "1"; # this is an evil default; make 'em set it!
6163 # Separator is =. Trying to set a value.
6164 elsif ($sep eq "=") {
6165 # If quoted, extract a quoted string.
6166 if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
6168 ($val = $2) =~ s/\\([$quote\\])/$1/g;
6171 # Not quoted. Use the whole thing. Warn about 'option='.
6172 # XXX Spurious messages about clearing nonexistent options
6173 # XXX can be created, e.g., 'o googleWhack='.
6177 print OUT qq(Option better cleared using $opt=""\n)
6179 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
6181 } ## end elsif ($sep eq "=")
6183 # "Quoted" with [], <>, or {}.
6184 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
6185 my ($end) = "\\" . substr(")]>}$sep", index("([<{", $sep), 1); #}
6186 s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
6187 or print($OUT "Unclosed option value `$opt$sep$_'\n"), last;
6188 ($val = $1) =~ s/\\([\\$end])/$1/g;
6189 } ## end else [ if ("?" eq $sep)
6193 # Make sure that such an option exists.
6194 my $matches = grep(/^\Q$opt/ && ($option = $_), @options) ||
6195 grep(/^\Q$opt/i && ($option = $_), @options);
6197 print($OUT "Unknown option `$opt'\n"), next unless $matches;
6198 print($OUT "Ambiguous option `$opt'\n"), next if $matches > 1;
6200 # Exclude non-booleans from getting set to 1 by default.
6201 if ($opt_needs_val{$option} && $val_defaulted) {
6202 my $cmd = ($CommandSet eq '580') ? 'o' : 'O';
6204 "Option `$opt' is non-boolean. Use `$cmd $option=VAL' to set, `$cmd $option?' to query\n";
6206 } ## end if ($opt_needs_val{$option...
6208 # Save the option value.
6209 $option{$option} = $val if defined $val;
6211 # Load any module that this option requires.
6215 require '$optionRequire{$option}';
6217 } || die # XXX: shouldn't happen
6218 if defined $optionRequire{$option} &&
6222 # Stick it in the proper variable if it goes in a variable.
6223 ${ $optionVars{$option} } = $val
6224 if defined $optionVars{$option} &&
6227 # Call the appropriate sub if it gets set via sub.
6228 &{ $optionAction{$option} }($val)
6229 if defined $optionAction{$option} &&
6230 defined &{ $optionAction{$option} } &&
6233 # Not initialization - echo the value we set it to.
6234 dump_option($option) unless $OUT eq \*STDERR;
6235 } ## end while (length)
6236 } ## end sub parse_options
6238 =head1 RESTART SUPPORT
6240 These routines are used to store (and restore) lists of items in environment
6241 variables during a restart.
6245 Set_list packages up items to be stored in a set of environment variables
6246 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
6247 the values). Values outside the standard ASCII charset are stored by encoding
6248 then as hexadecimal values.
6253 my ($stem, @list) = @_;
6256 # VAR_n: how many we have. Scalar assignment gets the number of items.
6257 $ENV{"${stem}_n"} = @list;
6259 # Grab each item in the list, escape the backslashes, encode the non-ASCII
6260 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
6261 for $i (0 .. $#list) {
6263 $val =~ s/\\/\\\\/g;
6264 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
6265 $ENV{"${stem}_$i"} = $val;
6266 } ## end for $i (0 .. $#list)
6267 } ## end sub set_list
6271 Reverse the set_list operation: grab VAR_n to see how many we should be getting
6272 back, and then pull VAR_0, VAR_1. etc. back out.
6279 my $n = delete $ENV{"${stem}_n"};
6281 for $i (0 .. $n - 1) {
6282 $val = delete $ENV{"${stem}_$i"};
6283 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
6287 } ## end sub get_list
6289 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
6293 The C<catch()> subroutine is the essence of fast and low-impact. We simply
6294 set an already-existing global scalar variable to a constant value. This
6295 avoids allocating any memory possibly in the middle of something that will
6296 get all confused if we do.
6302 return; # Put nothing on the stack - malloc/free land!
6307 C<warn> emits a warning, by joining together its arguments and printing
6308 them, with couple of fillips.
6310 If the composited message I<doesn't> end with a newline, we automatically
6311 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
6312 to be set to the filehandle to be used to output warnings; it makes no
6313 assumptions about what filehandles are available.
6318 my ($msg) = join ("", @_);
6319 $msg .= ": $!\n" unless $msg =~ /\n$/;
6324 =head1 INITIALIZATION TTY SUPPORT
6326 =head2 C<reset_IN_OUT>
6328 This routine handles restoring the debugger's input and output filehandles
6329 after we've tried and failed to move them elsewhere. In addition, it assigns
6330 the debugger's output filehandle to $LINEINFO if it was already open there.
6335 my $switch_li = $LINEINFO eq $OUT;
6337 # If there's a term and it's able to get a new tty, try to get one.
6338 if ($term and $term->Features->{newTTY}) {
6339 ($IN, $OUT) = (shift, shift);
6340 $term->newTTY($IN, $OUT);
6343 # This term can't get a new tty now. Better luck later.
6345 &warn("Too late to set IN/OUT filehandles, enabled on next `R'!\n");
6348 # Set the filehndles up as they were.
6350 ($IN, $OUT) = (shift, shift);
6353 # Unbuffer the output filehandle.
6354 my $o = select $OUT;
6358 # Point LINEINFO to the same output filehandle if it was there before.
6359 $LINEINFO = $OUT if $switch_li;
6360 } ## end sub reset_IN_OUT
6362 =head1 OPTION SUPPORT ROUTINES
6364 The following routines are used to process some of the more complicated
6369 Sets the input and output filehandles to the specified files or pipes.
6370 If the terminal supports switching, we go ahead and do it. If not, and
6371 there's already a terminal in place, we save the infomation to take effect
6374 If there's no terminal yet (for instance, during debugger initialization),
6375 we go ahead and set C<$console> and C<$tty> to the file indicated.
6380 if (@_ and $term and $term->Features->{newTTY}) {
6381 # This terminal supports switching to a new TTY.
6382 # Can be a list of two files, or on string containing both names,
6384 # XXX Should this perhaps be an assignment from @_?
6385 my ($in, $out) = shift;
6387 # Split list apart if supplied.
6388 ($in, $out) = split /,/, $in, 2;
6391 # Use the same file for both input and output.
6395 # Open file onto the debugger's filehandles, if you can.
6396 open IN, $in or die "cannot open `$in' for read: $!";
6397 open OUT, ">$out" or die "cannot open `$out' for write: $!";
6399 # Swap to the new filehandles.
6400 reset_IN_OUT(\*IN, \*OUT);
6402 # Save the setting for later.
6404 } ## end if (@_ and $term and $term...
6406 # Terminal doesn't support new TTY, or doesn't support readline.
6407 # Can't do it now, try restarting.
6408 &warn("Too late to set TTY, enabled on next `R'!\n") if $term and @_;
6410 # Useful if done through PERLDB_OPTS:
6411 $console = $tty = shift if @_;
6413 # Return whatever the TTY is.
6419 Sets the C<$notty> global, controlling whether or not the debugger tries to
6420 get a terminal to read from. If called after a terminal is already in place,
6421 we save the value to use it if we're restarted.
6427 &warn("Too late to set noTTY, enabled on next `R'!\n") if @_;
6429 $notty = shift if @_;
6435 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
6436 (essentially, no C<readline> processing on this "terminal"). Otherwise, we
6437 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
6438 the value in case a restart is done so we can change it then.
6444 &warn("Too late to set ReadLine, enabled on next `R'!\n") if @_;
6448 } ## end sub ReadLine
6450 =head2 C<RemotePort>
6452 Sets the port that the debugger will try to connect to when starting up.
6453 If the terminal's already been set up, we can't do it, but we remember the
6454 setting in case the user does a restart.
6460 &warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
6462 $remoteport = shift if @_;
6464 } ## end sub RemotePort
6468 Checks with the terminal to see if C<Tk> is running, and returns true or
6469 false. Returns false if the current terminal doesn't support C<readline>.
6474 if (${ $term->Features }{tkRunning}) {
6475 return $term->tkRunning(@_);
6479 print $OUT "tkRunning not supported by current ReadLine package.\n";
6482 } ## end sub tkRunning
6486 Sets nonstop mode. If a terminal's already been set up, it's too late; the
6487 debugger remembers the setting in case you restart, though.
6493 &warn("Too late to set up NonStop mode, enabled on next `R'!\n")
6496 $runnonstop = shift if @_;
6498 } ## end sub NonStop
6502 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
6510 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
6517 Sets the shell escape command, and generates a printable copy to be used
6524 # If we got an argument, meta-quote it, and add '\b' if it
6525 # ends in a word character.
6527 $sh = quotemeta shift;
6528 $sh .= "\\b" if $sh =~ /\w$/;
6531 # Generate the printable version for the help:
6532 $psh = $sh; # copy it
6533 $psh =~ s/\\b$//; # Take off trailing \b if any
6534 $psh =~ s/\\(.)/$1/g; # De-escape
6535 $psh; # return the printable version
6536 } ## end sub shellBang
6540 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
6541 was passed as the argument. (This means you can't override the terminal's
6547 if (defined $term) {
6548 # We don't want to show warning backtraces, but we do want die() ones.
6549 local ($warnLevel, $dieLevel) = (0, 1);
6551 # No ornaments if the terminal doesn't support them.
6552 return '' unless $term->Features->{ornaments};
6553 eval { $term->ornaments(@_) } || '';
6556 # Use what was passed in if we can't determine it ourselves.
6560 } ## end sub ornaments
6562 =head2 C<recallCommand>
6564 Sets the recall command, and builds a printable version which will appear in
6571 # If there is input, metaquote it. Add '\b' if it ends with a word
6574 $rc = quotemeta shift;
6575 $rc .= "\\b" if $rc =~ /\w$/;
6578 # Build it into a printable version.
6579 $prc = $rc; # Copy it
6580 $prc =~ s/\\b$//; # Remove trailing \b
6581 $prc =~ s/\\(.)/$1/g; # Remove escapes
6582 $prc; # Return the printable version
6583 } ## end sub recallCommand
6585 =head2 C<LineInfo> - where the line number information goes
6587 Called with no arguments, returns the file or pipe that line info should go to.
6589 Called with an argument (a file or a pipe), it opens that onto the
6590 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
6591 file or pipe again to the caller.
6596 return $lineinfo unless @_;
6599 # If this is a valid "thing to be opened for output", tack a
6600 # '>' onto the front.
6601 my $stream = ($lineinfo =~ /^(\+?\>|\|)/) ? $lineinfo : ">$lineinfo";
6603 # If this is a pipe, the stream points to a slave editor.
6604 $slave_editor = ($stream =~ /^\|/);
6606 # Open it up and unbuffer it.
6607 open(LINEINFO, "$stream") || &warn("Cannot open `$stream' for write");
6608 $LINEINFO = \*LINEINFO;
6609 my $save = select($LINEINFO);
6613 # Hand the file or pipe back again.
6615 } ## end sub LineInfo
6617 =head1 COMMAND SUPPORT ROUTINES
6619 These subroutines provide functionality for various commands.
6621 =head2 C<list_modules>
6623 For the C<M> command: list modules loaded and their versions.
6624 Essentially just runs through the keys in %INC, picks up the
6625 $VERSION package globals from each package, gets the file name, and formats the
6626 information for output.
6630 sub list_modules { # versions
6633 # keys are the "as-loaded" name, values are the fully-qualified path
6634 # to the file itself.
6636 $file = $_; # get the module name
6637 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
6638 s,/,::,g; # change '/' to '::'
6639 s/^perl5db$/DB/; # Special case: debugger
6640 # moves to package DB
6641 s/^Term::ReadLine::readline$/readline/; # simplify readline
6643 # If the package has a $VERSION package global (as all good packages
6644 # should!) decode it and save as partial message.
6645 if (defined ${ $_ . '::VERSION' }) {
6646 $version{$file} = "${ $_ . '::VERSION' } from ";
6649 # Finish up the message with the file the package came from.
6650 $version{$file} .= $INC{$file};
6651 } ## end for (keys %INC)
6653 # Hey, dumpit() formats a hash nicely, so why not use it?
6654 dumpit($OUT, \%version);
6655 } ## end sub list_modules
6659 Sets up the monster string used to format and print the help.
6661 =head3 HELP MESSAGE FORMAT
6663 The help message is a peculiar format unto itself; it mixes C<pod> 'ornaments'
6664 (BE<lt>E<gt>, IE<gt>E<lt>) with tabs to come up with a format that's fairly
6665 easy to parse and portable, but which still allows the help to be a little
6666 nicer than just plain text.
6668 Essentially, you define the command name (usually marked up with BE<gt>E<lt>
6669 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
6670 need to continue the descriptive text to another line, start that line with
6671 just tabs and then enter the marked-up text.
6673 If you are modifying the help text, I<be careful>. The help-string parser is
6674 not very sophisticated, and if you don't follow these rules it will mangle the
6675 help beyond hope until you fix the string.
6681 # XXX: make sure there are tabs between the command and explanation,
6682 # or print_help will screw up your formatting if you have
6683 # eeevil ornaments enabled. This is an insane mess.
6686 Help is currently only available for the new 5.8 command set.
6687 No help is available for the old command set.
6688 We assume you know what you're doing if you switch to it.
6691 B<s> [I<expr>] Single step [in I<expr>].
6692 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
6693 <B<CR>> Repeat last B<n> or B<s> command.
6694 B<r> Return from current subroutine.
6695 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
6696 at the specified position.
6697 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
6698 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
6699 B<l> I<line> List single I<line>.
6700 B<l> I<subname> List first window of lines from subroutine.
6701 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
6702 B<l> List next window of lines.
6703 B<-> List previous window of lines.
6704 B<v> [I<line>] View window around I<line>.
6705 B<.> Return to the executed line.
6706 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
6707 I<filename> may be either the full name of the file, or a regular
6708 expression matching the full file name:
6709 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
6710 Evals (with saved bodies) are considered to be filenames:
6711 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
6712 (in the order of execution).
6713 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
6714 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
6715 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
6716 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
6717 B<t> Toggle trace mode.
6718 B<t> I<expr> Trace through execution of I<expr>.
6719 B<b> Sets breakpoint on current line)
6720 B<b> [I<line>] [I<condition>]
6721 Set breakpoint; I<line> defaults to the current execution line;
6722 I<condition> breaks if it evaluates to true, defaults to '1'.
6723 B<b> I<subname> [I<condition>]
6724 Set breakpoint at first line of subroutine.
6725 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
6726 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
6727 B<b> B<postpone> I<subname> [I<condition>]
6728 Set breakpoint at first line of subroutine after
6730 B<b> B<compile> I<subname>
6731 Stop after the subroutine is compiled.
6732 B<B> [I<line>] Delete the breakpoint for I<line>.
6733 B<B> I<*> Delete all breakpoints.
6734 B<a> [I<line>] I<command>
6735 Set an action to be done before the I<line> is executed;
6736 I<line> defaults to the current execution line.
6737 Sequence is: check for breakpoint/watchpoint, print line
6738 if necessary, do action, prompt user if necessary,
6741 B<A> [I<line>] Delete the action for I<line>.
6742 B<A> I<*> Delete all actions.
6743 B<w> I<expr> Add a global watch-expression.
6745 B<W> I<expr> Delete a global watch-expression.
6746 B<W> I<*> Delete all watch-expressions.
6747 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
6748 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
6749 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
6750 B<x> I<expr> Evals expression in list context, dumps the result.
6751 B<m> I<expr> Evals expression in list context, prints methods callable
6752 on the first element of the result.
6753 B<m> I<class> Prints methods callable via the given class.
6754 B<M> Show versions of loaded modules.
6755 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
6757 B<<> ? List Perl commands to run before each prompt.
6758 B<<> I<expr> Define Perl command to run before each prompt.
6759 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
6760 B<< *> Delete the list of perl commands to run before each prompt.
6761 B<>> ? List Perl commands to run after each prompt.
6762 B<>> I<expr> Define Perl command to run after each prompt.
6763 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
6764 B<>>B< *> Delete the list of Perl commands to run after each prompt.
6765 B<{> I<db_command> Define debugger command to run before each prompt.
6766 B<{> ? List debugger commands to run before each prompt.
6767 B<{ *> Delete the list of debugger commands to run before each prompt.
6768 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
6769 B<$prc> I<number> Redo a previous command (default previous command).
6770 B<$prc> I<-number> Redo number'th-to-last command.
6771 B<$prc> I<pattern> Redo last command that started with I<pattern>.
6772 See 'B<O> I<recallCommand>' too.
6773 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
6778 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
6781 See 'B<O> I<shellBang>' too.
6782 B<source> I<file> Execute I<file> containing debugger commands (may nest).
6783 B<H> I<-number> Display last number commands (default all).
6784 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
6785 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
6786 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
6787 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
6788 I<command> Execute as a perl statement in current package.
6789 B<R> Pure-man-restart of debugger, some of debugger state
6790 and command-line options may be lost.
6791 Currently the following settings are preserved:
6792 history, breakpoints and actions, debugger B<O>ptions
6793 and the following command-line options: I<-w>, I<-I>, I<-e>.
6795 B<o> [I<opt>] ... Set boolean option to true
6796 B<o> [I<opt>B<?>] Query options
6797 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
6798 Set options. Use quotes in spaces in value.
6799 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
6800 I<pager> program for output of \"|cmd\";
6801 I<tkRunning> run Tk while prompting (with ReadLine);
6802 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
6803 I<inhibit_exit> Allows stepping off the end of the script.
6804 I<ImmediateStop> Debugger should stop as early as possible.
6805 I<RemotePort> Remote hostname:port for remote debugging
6806 The following options affect what happens with B<V>, B<X>, and B<x> commands:
6807 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
6808 I<compactDump>, I<veryCompact> change style of array and hash dump;
6809 I<globPrint> whether to print contents of globs;
6810 I<DumpDBFiles> dump arrays holding debugged files;
6811 I<DumpPackages> dump symbol tables of packages;
6812 I<DumpReused> dump contents of \"reused\" addresses;
6813 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
6814 I<bareStringify> Do not print the overload-stringified value;
6815 Other options include:
6816 I<PrintRet> affects printing of return value after B<r> command,
6817 I<frame> affects printing messages on subroutine entry/exit.
6818 I<AutoTrace> affects printing messages on possible breaking points.
6819 I<maxTraceLen> gives max length of evals/args listed in stack trace.
6820 I<ornaments> affects screen appearance of the command line.
6821 I<CreateTTY> bits control attempts to create a new TTY on events:
6822 1: on fork() 2: debugger is started inside debugger
6824 During startup options are initialized from \$ENV{PERLDB_OPTS}.
6825 You can put additional initialization options I<TTY>, I<noTTY>,
6826 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
6827 `B<R>' after you set them).
6829 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
6830 B<h> Summary of debugger commands.
6831 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
6832 B<h h> Long help for debugger commands
6833 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
6834 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
6835 Set B<\$DB::doccmd> to change viewer.
6837 Type `|h h' for a paged display if this was too hard to read.
6839 "; # Fix balance of vi % matching: }}}}
6841 # note: tabs in the following section are not-so-helpful
6842 $summary = <<"END_SUM";
6843 I<List/search source lines:> I<Control script execution:>
6844 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
6845 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
6846 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
6847 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
6848 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
6849 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
6850 I<Debugger controls:> B<L> List break/watch/actions
6851 B<o> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
6852 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
6853 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
6854 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
6855 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
6856 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
6857 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
6858 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
6859 B<q> or B<^D> Quit B<R> Attempt a restart
6860 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
6861 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
6862 B<p> I<expr> Print expression (uses script's current package).
6863 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
6864 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
6865 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
6866 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
6867 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
6870 # ')}}; # Fix balance of vi % matching
6872 # and this is really numb...
6875 B<s> [I<expr>] Single step [in I<expr>].
6876 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
6877 B<CR>> Repeat last B<n> or B<s> command.
6878 B<r> Return from current subroutine.
6879 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
6880 at the specified position.
6881 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
6882 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
6883 B<l> I<line> List single I<line>.
6884 B<l> I<subname> List first window of lines from subroutine.
6885 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
6886 B<l> List next window of lines.
6887 B<-> List previous window of lines.
6888 B<w> [I<line>] List window around I<line>.
6889 B<.> Return to the executed line.
6890 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
6891 I<filename> may be either the full name of the file, or a regular
6892 expression matching the full file name:
6893 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
6894 Evals (with saved bodies) are considered to be filenames:
6895 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
6896 (in the order of execution).
6897 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
6898 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
6899 B<L> List all breakpoints and actions.
6900 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
6901 B<t> Toggle trace mode.
6902 B<t> I<expr> Trace through execution of I<expr>.
6903 B<b> [I<line>] [I<condition>]
6904 Set breakpoint; I<line> defaults to the current execution line;
6905 I<condition> breaks if it evaluates to true, defaults to '1'.
6906 B<b> I<subname> [I<condition>]
6907 Set breakpoint at first line of subroutine.
6908 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
6909 B<b> B<load> I<filename> Set breakpoint on `require'ing the given file.
6910 B<b> B<postpone> I<subname> [I<condition>]
6911 Set breakpoint at first line of subroutine after
6913 B<b> B<compile> I<subname>
6914 Stop after the subroutine is compiled.
6915 B<d> [I<line>] Delete the breakpoint for I<line>.
6916 B<D> Delete all breakpoints.
6917 B<a> [I<line>] I<command>
6918 Set an action to be done before the I<line> is executed;
6919 I<line> defaults to the current execution line.
6920 Sequence is: check for breakpoint/watchpoint, print line
6921 if necessary, do action, prompt user if necessary,
6923 B<a> [I<line>] Delete the action for I<line>.
6924 B<A> Delete all actions.
6925 B<W> I<expr> Add a global watch-expression.
6926 B<W> Delete all watch-expressions.
6927 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
6928 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
6929 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
6930 B<x> I<expr> Evals expression in list context, dumps the result.
6931 B<m> I<expr> Evals expression in list context, prints methods callable
6932 on the first element of the result.
6933 B<m> I<class> Prints methods callable via the given class.
6935 B<<> ? List Perl commands to run before each prompt.
6936 B<<> I<expr> Define Perl command to run before each prompt.
6937 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
6938 B<>> ? List Perl commands to run after each prompt.
6939 B<>> I<expr> Define Perl command to run after each prompt.
6940 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
6941 B<{> I<db_command> Define debugger command to run before each prompt.
6942 B<{> ? List debugger commands to run before each prompt.
6943 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
6944 B<$prc> I<number> Redo a previous command (default previous command).
6945 B<$prc> I<-number> Redo number'th-to-last command.
6946 B<$prc> I<pattern> Redo last command that started with I<pattern>.
6947 See 'B<O> I<recallCommand>' too.
6948 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
6953 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
6956 See 'B<O> I<shellBang>' too.
6957 B<source> I<file> Execute I<file> containing debugger commands (may nest).
6958 B<H> I<-number> Display last number commands (default all).
6959 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
6960 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
6961 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
6962 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
6963 I<command> Execute as a perl statement in current package.
6964 B<v> Show versions of loaded modules.
6965 B<R> Pure-man-restart of debugger, some of debugger state
6966 and command-line options may be lost.
6967 Currently the following settings are preserved:
6968 history, breakpoints and actions, debugger B<O>ptions
6969 and the following command-line options: I<-w>, I<-I>, I<-e>.
6971 B<O> [I<opt>] ... Set boolean option to true
6972 B<O> [I<opt>B<?>] Query options
6973 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
6974 Set options. Use quotes in spaces in value.
6975 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
6976 I<pager> program for output of \"|cmd\";
6977 I<tkRunning> run Tk while prompting (with ReadLine);
6978 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
6979 I<inhibit_exit> Allows stepping off the end of the script.
6980 I<ImmediateStop> Debugger should stop as early as possible.
6981 I<RemotePort> Remote hostname:port for remote debugging
6982 The following options affect what happens with B<V>, B<X>, and B<x> commands:
6983 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
6984 I<compactDump>, I<veryCompact> change style of array and hash dump;
6985 I<globPrint> whether to print contents of globs;
6986 I<DumpDBFiles> dump arrays holding debugged files;
6987 I<DumpPackages> dump symbol tables of packages;
6988 I<DumpReused> dump contents of \"reused\" addresses;
6989 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
6990 I<bareStringify> Do not print the overload-stringified value;
6991 Other options include:
6992 I<PrintRet> affects printing of return value after B<r> command,
6993 I<frame> affects printing messages on subroutine entry/exit.
6994 I<AutoTrace> affects printing messages on possible breaking points.
6995 I<maxTraceLen> gives max length of evals/args listed in stack trace.
6996 I<ornaments> affects screen appearance of the command line.
6997 I<CreateTTY> bits control attempts to create a new TTY on events:
6998 1: on fork() 2: debugger is started inside debugger
7000 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7001 You can put additional initialization options I<TTY>, I<noTTY>,
7002 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7003 `B<R>' after you set them).
7005 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7006 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7007 B<h h> Summary of debugger commands.
7008 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7009 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7010 Set B<\$DB::doccmd> to change viewer.
7012 Type `|h' for a paged display if this was too hard to read.
7014 "; # Fix balance of vi % matching: }}}}
7016 # note: tabs in the following section are not-so-helpful
7017 $pre580_summary = <<"END_SUM";
7018 I<List/search source lines:> I<Control script execution:>
7019 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7020 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7021 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
7022 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7023 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7024 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
7025 I<Debugger controls:> B<L> List break/watch/actions
7026 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7027 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7028 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
7029 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7030 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
7031 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
7032 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7033 B<q> or B<^D> Quit B<R> Attempt a restart
7034 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7035 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7036 B<p> I<expr> Print expression (uses script's current package).
7037 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7038 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7039 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
7040 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7041 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7044 # ')}}; # Fix balance of vi % matching
7046 } ## end sub sethelp
7048 =head2 C<print_help()>
7050 Most of what C<print_help_ does is just text formatting. It finds the
7051 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
7052 terminal control characters to simulate them (courtesy of
7053 <Term::ReadLine::TermCap>).
7060 # Restore proper alignment destroyed by eeevil I<> and B<>
7061 # ornaments: A pox on both their houses!
7063 # A help command will have everything up to and including
7064 # the first tab sequence padded into a field 16 (or if indented 20)
7065 # wide. If it's wider than that, an extra space will be added.
7067 ^ # only matters at start of line
7068 ( \040{4} | \t )* # some subcommands are indented
7069 ( < ? # so <CR> works
7070 [BI] < [^\t\n] + ) # find an eeevil ornament
7071 ( \t+ ) # original separation, discarded
7072 ( .* ) # this will now start (no earlier) than
7075 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
7076 my $clean = $command;
7077 $clean =~ s/[BI]<([^>]*)>/$1/g;
7079 # replace with this whole string:
7080 ($leadwhite ? " " x 4 : "")
7082 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
7087 s{ # handle bold ornaments
7088 B < ( [^>] + | > ) >
7090 $Term::ReadLine::TermCap::rl_term_set[2]
7092 . $Term::ReadLine::TermCap::rl_term_set[3]
7095 s{ # handle italic ornaments
7096 I < ( [^>] + | > ) >
7098 $Term::ReadLine::TermCap::rl_term_set[0]
7100 . $Term::ReadLine::TermCap::rl_term_set[1]
7105 } ## end sub print_help
7109 This routine does a lot of gyrations to be sure that the pager is C<less>.
7110 It checks for C<less> masquerading as C<more> and records the result in
7111 C<$ENV{LESS}> so we don't have to go through doing the stats again.
7117 # We already know if this is set.
7118 return if defined $ENV{LESS} && $ENV{LESS} =~ /r/;
7120 # Pager is less for sure.
7121 my $is_less = $pager =~ /\bless\b/;
7122 if ($pager =~ /\bmore\b/) {
7123 # Nope, set to more. See what's out there.
7124 my @st_more = stat('/usr/bin/more');
7125 my @st_less = stat('/usr/bin/less');
7127 # is it really less, pretending to be more?
7128 $is_less = @st_more &&
7130 $st_more[0] == $st_less[0] &&
7131 $st_more[1] == $st_less[1];
7132 } ## end if ($pager =~ /\bmore\b/)
7134 # changes environment!
7135 # 'r' added so we don't do (slow) stats again.
7136 $ENV{LESS} .= 'r' if $is_less;
7137 } ## end sub fix_less
7139 =head1 DIE AND WARN MANAGEMENT
7143 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
7144 to debug a debugger problem.
7146 It does its best to report the error that occurred, and then forces the
7147 program, debugger, and everything to die.
7152 # No entry/exit messages.
7155 # No return value prints.
7158 # set the abort signal handling to the default (just terminate).
7159 $SIG{'ABRT'} = 'DEFAULT';
7161 # If we enter the signal handler recursively, kill myself with an
7162 # abort signal (so we just terminate).
7163 kill 'ABRT', $$ if $panic++;
7165 # If we can show detailed info, do so.
7166 if (defined &Carp::longmess) {
7167 # Don't recursively enter the warn handler, since we're carping.
7168 local $SIG{__WARN__} = '';
7170 # Skip two levels before reporting traceback: we're skipping
7171 # mydie and confess.
7172 local $Carp::CarpLevel = 2; # mydie + confess
7174 # Tell us all about it.
7175 &warn(Carp::longmess("Signal @_"));
7178 # No Carp. Tell us about the signal as best we can.
7181 print $DB::OUT "Got signal @_\n";
7186 } ## end sub diesignal
7190 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
7191 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
7196 # No entry/exit trace.
7199 # No return value printing.
7202 # Turn off warn and die handling to prevent recursive entries to this
7204 local $SIG{__WARN__} = '';
7205 local $SIG{__DIE__} = '';
7207 # Load Carp if we can. If $^S is false (current thing being compiled isn't
7208 # done yet), we may not be able to do a require.
7209 eval { require Carp }
7210 if defined $^S; # If error/warning during compilation,
7211 # require may be broken.
7213 # Use the core warn() unless Carp loaded OK.
7215 "\nCannot print stack trace, load with -MCarp option to see stack"),
7217 unless defined &Carp::longmess;
7219 # Save the current values of $single and $trace, and then turn them off.
7220 my ($mysingle, $mytrace) = ($single, $trace);
7224 # We can call Carp::longmess without its being "debugged" (which we
7225 # don't want - we just want to use it!). Capture this for later.
7226 my $mess = Carp::longmess(@_);
7228 # Restore $single and $trace to their original values.
7229 ($single, $trace) = ($mysingle, $mytrace);
7231 # Use the debugger's own special way of printing warnings to print
7232 # the stack trace message.
7238 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
7239 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
7240 single stepping and tracing during the call to C<Carp::longmess> to avoid
7241 debugging it - we just want to use it.
7243 If C<dieLevel> is zero, we let the program being debugged handle the
7244 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
7245 the debugger takes over all exception handling, printing a backtrace and
7246 displaying the exception via its C<dbwarn()> routine.
7253 local $SIG{__DIE__} = '';
7254 local $SIG{__WARN__} = '';
7258 if ($dieLevel > 2) {
7259 local $SIG{__WARN__} = \&dbwarn;
7260 &warn(@_); # Yell no matter what
7263 if ($dieLevel < 2) {
7264 die @_ if $^S; # in eval propagate
7267 # The code used to check $^S to see if compiliation of the current thing
7268 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
7269 eval { require Carp };
7272 "\nCannot print stack trace, load with -MCarp option to see stack")
7273 unless defined &Carp::longmess;
7275 # We do not want to debug this chunk (automatic disabling works
7276 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
7277 # get the stack trace from Carp::longmess (if possible), restore $signal
7278 # and $trace, and then die with the stack trace.
7279 my ($mysingle, $mytrace) = ($single, $trace);
7285 package Carp; # Do not include us in the list
7286 eval { $mess = Carp::longmess(@_); };
7288 ($single, $trace) = ($mysingle, $mytrace);
7292 =head2 C<warnlevel()>
7294 Set the C<$DB::warnLevel> variable that stores the value of the C<warnLevel>
7295 option. Calling C<warnLevel()> with a positive value results in the debugger taking over all warning handlers.Setting C<warnLevel> to zero leaves any warning
7296 handlers set up by the program being debugged in place.
7302 $prevwarn = $SIG{__WARN__} unless $warnLevel;
7305 $SIG{__WARN__} = \&DB::dbwarn;
7308 $SIG{__WARN__} = $prevwarn;
7312 } ## end sub warnLevel
7316 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
7317 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
7318 zero lets you use your own C<die()> handler.
7325 $prevdie = $SIG{__DIE__} unless $dieLevel;
7328 # Always set it to dbdie() for non-zero values.
7329 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
7331 # No longer exists, so don't try to use it.
7332 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
7334 # If we've finished initialization, mention that stack dumps
7335 # are enabled, If dieLevel is 1, we won't stack dump if we die
7337 print $OUT "Stack dump during die enabled",
7338 ($dieLevel == 1 ? " outside of evals" : ""), ".\n"
7341 # XXX This is probably obsolete, given that diehard() is gone.
7342 print $OUT "Dump printed too.\n" if $dieLevel > 2;
7343 } ## end if ($dieLevel)
7345 # Put the old one back if there was one.
7347 $SIG{__DIE__} = $prevdie;
7348 print $OUT "Default die handler restored.\n";
7352 } ## end sub dieLevel
7354 =head2 C<signalLevel>
7356 Number three in a series: set C<signalLevel> to zero to keep your own
7357 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Oherwise, the debugger
7358 takes over and handles them with C<DB::diesignal()>.
7364 $prevsegv = $SIG{SEGV} unless $signalLevel;
7365 $prevbus = $SIG{BUS} unless $signalLevel;
7366 $signalLevel = shift;
7368 $SIG{SEGV} = \&DB::diesignal;
7369 $SIG{BUS} = \&DB::diesignal;
7372 $SIG{SEGV} = $prevsegv;
7373 $SIG{BUS} = $prevbus;
7377 } ## end sub signalLevel
7379 =head1 SUBROUTINE DECODING SUPPORT
7381 These subroutines are used duting the C<x> and C<X> commands to try to
7382 produce as much information as possible about a code reference. They use
7383 L<Devel::Peek> to try to find the glob in which this code reference lives
7384 (if it does) - this allows us to actually code references which correspond
7385 to named subroutines (including those aliased via glob assignment).
7387 =head2 C<CvGV_name()>
7389 Wrapper for X<CvGV_name_or_bust>; tries to get the name of a reference
7390 via that routine. If this fails, return the reference again (when the
7391 reference is stringified, it'll come out as "SOMETHING(0X...)").
7397 my $name = CvGV_name_or_bust($in);
7398 defined $name ? $name : $in;
7401 =head2 C<CvGV_name_or_bust> I<coderef>
7403 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
7404 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
7405 find a glob for this ref.
7407 Returns "I<package>::I<glob name>" if the code ref is found in a glob.
7411 sub CvGV_name_or_bust {
7413 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
7414 return unless ref $in;
7415 $in = \&$in; # Hard reference...
7416 eval { require Devel::Peek; 1 } or return;
7417 my $gv = Devel::Peek::CvGV($in) or return;
7418 *$gv{PACKAGE} . '::' . *$gv{NAME};
7419 } ## end sub CvGV_name_or_bust
7423 A utility routine used in various places; finds the file where a subroutine
7424 was defined, and returns that filename and a line-number range.
7426 Tries to use X<@sub> first; if it can't find it there, it tries building a
7427 reference to the subroutine and uses X<CvGV_name_or_bust> to locate it,
7428 loading it into X<@sub> as a side effect (XXX I think). If it can't find it
7429 this way, it brute-force searches X<%sub>, checking for identical references.
7436 return unless defined &$subr;
7437 my $name = CvGV_name_or_bust($subr);
7439 $data = $sub{$name} if defined $name;
7440 return $data if defined $data;
7443 $subr = \&$subr; # Hard reference
7446 $s = $_, last if $subr eq \&$_;
7450 } ## end sub find_sub
7454 A subroutine that uses the utility function X<methods_via> to find all the
7455 methods in the class corresponding to the current reference and in
7462 # Figure out the class - either this is the class or it's a reference
7463 # to something blessed into that class.
7465 $class = ref $class if ref $class;
7470 # Show the methods that this class has.
7471 methods_via($class, '', 1);
7473 # Show the methods that UNIVERSAL has.
7474 methods_via('UNIVERSAL', 'UNIVERSAL', 0);
7475 } ## end sub methods
7477 =head2 C<methods_via($class, $prefix, $crawl_upward)>
7479 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
7480 all the parent class methods. C<$class> is the name of the next class to
7481 try; C<$prefix> is the message prefix, which gets built up as we go up the
7482 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
7483 higher in the C<@ISA> tree, 0 if we should stop.
7488 # If we've processed this class already, just quit.
7491 # XXX This may be a bug - no other references to %packs.
7492 return if $packs{$class}++;
7494 # This is a package that is contributing the methods we're about to print.
7496 my $prepend = $prefix ? "via $prefix: " : '';
7500 # Keep if this is a defined subroutine in this class.
7501 grep { defined &{ ${"${class}::"}{$_} } }
7502 # Extract from all the symbols in this class.
7503 sort keys %{"${class}::"}
7505 # XXX This should probably be %packs (or %packs should be %seen).
7506 next if $seen{$name}++;
7509 print $DB::OUT "$prepend$name\n";
7510 } ## end for $name (grep { defined...
7512 # If the $crawl_upward argument is false, just quit here.
7513 return unless shift;
7515 # $crawl_upward true: keep going up the tree.
7516 # Find all the classes this one is a subclass of.
7517 for $name (@{"${class}::ISA"}) {
7518 # Set up the new prefix.
7519 $prepend = $prefix ? $prefix . " -> $name" : $name;
7520 # Crawl up the tree and keep trying to crawl up.
7521 methods_via($name, $prepend, 1);
7523 } ## end sub methods_via
7525 =head2 C<setman> - figure out which command to use to show documentation
7527 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
7533 $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|MacOS|NetWare)\z/s
7534 ? "man" # O Happy Day!
7535 : "perldoc"; # Alas, poor unfortunates
7538 =head2 C<runman> - run the appropriate command to show documentation
7540 Accepts a man page name; runs the appropriate command to display it (set up
7541 during debugger initialization). Uses C<DB::system> to avoid mucking up the
7542 program's STDIN and STDOUT.
7549 &system("$doccmd $doccmd");
7553 # this way user can override, like with $doccmd="man -Mwhatever"
7554 # or even just "man " to disable the path check.
7555 unless ($doccmd eq 'man') {
7556 &system("$doccmd $page");
7560 $page = 'perl' if lc($page) eq 'help';
7563 my $man1dir = $Config::Config{'man1dir'};
7564 my $man3dir = $Config::Config{'man3dir'};
7565 for ($man1dir, $man3dir) { s#/[^/]*\z## if /\S/ }
7567 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
7568 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
7569 chop $manpath if $manpath;
7571 # harmless if missing, I figure
7572 my $oldpath = $ENV{MANPATH};
7573 $ENV{MANPATH} = $manpath if $manpath;
7574 my $nopathopt = $^O =~ /dunno what goes here/;
7579 # I just *know* there are men without -M
7580 (($manpath && !$nopathopt) ? ("-M", $manpath) : ()),
7585 unless ($page =~ /^perl\w/) {
7587 grep { $page eq $_ }
7589 5004delta 5005delta amiga api apio book boot bot call compile
7590 cygwin data dbmfilter debug debguts delta diag doc dos dsc embed
7591 faq faq1 faq2 faq3 faq4 faq5 faq6 faq7 faq8 faq9 filter fork
7592 form func guts hack hist hpux intern ipc lexwarn locale lol mod
7593 modinstall modlib number obj op opentut os2 os390 pod port
7594 ref reftut run sec style sub syn thrtut tie toc todo toot tootc
7595 trap unicode var vms win32 xs xstut
7600 CORE::system($doccmd,
7601 (($manpath && !$nopathopt) ? ("-M", $manpath) : ()),
7603 } ## end if (grep { $page eq $_...
7604 } ## end unless ($page =~ /^perl\w/)
7605 } ## end if (CORE::system($doccmd...
7606 if (defined $oldpath) {
7607 $ENV{MANPATH} = $manpath;
7610 delete $ENV{MANPATH};
7614 #use Carp; # This did break, left for debugging
7616 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
7618 Because of the way the debugger interface to the Perl core is designed, any
7619 debugger package globals that C<DB::sub()> requires have to be defined before
7620 any subroutines can be called. These are defined in the second C<BEGIN> block.
7622 This block sets things up so that (basically) the world is sane
7623 before the debugger starts executing. We set up various variables that the
7624 debugger has to have set up before the Perl core starts running:
7628 =item * The debugger's own filehandles (copies of STD and STDOUT for now).
7630 =item * Characters for shell escapes, the recall command, and the history command.
7632 =item * The maximum recursion depth.
7634 =item * The size of a C<w> command's window.
7636 =item * The before-this-line context to be printed in a C<v> (view a window around this line) command.
7638 =item * The fact that we're not in a sub at all right now.
7640 =item * The default SIGINT handler for the debugger.
7642 =item * The appropriate value of the flag in C<$^D> that says the debugger is running
7644 =item * The current debugger recursion level
7646 =item * The list of postponed (XXX define) items and the C<$single> stack
7648 =item * That we want no return values and no subroutine entry/exit trace.
7652 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
7654 BEGIN { # This does not compile, alas. (XXX eh?)
7655 $IN = \*STDIN; # For bugs before DB::OUT has been opened
7656 $OUT = \*STDERR; # For errors before DB::OUT has been opened
7658 # Define characters used by command parsing.
7659 $sh = '!'; # Shell escape (does not work)
7660 $rc = ','; # Recall command (does not work)
7661 @hist = ('?'); # Show history (does not work)
7663 # This defines the point at which you get the 'deep recursion'
7664 # warning. It MUST be defined or the debugger will not load.
7667 # Number of lines around the current one that are shown in the
7671 # How much before-the-current-line context the 'v' command should
7672 # use in calculating the start of the window it will display.
7675 # We're not in any sub yet, but we need this to be a defined value.
7678 # Set up the debugger's interrupt handler. It simply sets a flag
7679 # ($signal) that DB::DB() will check before each command is executed.
7680 $SIG{INT} = \&DB::catch;
7682 # The following lines supposedly, if uncommented, allow the debugger to
7683 # debug itself. Perhaps we can try that someday.
7684 # This may be enabled to debug debugger:
7685 #$warnLevel = 1 unless defined $warnLevel;
7686 #$dieLevel = 1 unless defined $dieLevel;
7687 #$signalLevel = 1 unless defined $signalLevel;
7689 # This is the flag that says "a debugger is running, please call
7690 # DB::DB and DB::sub". We will turn it on forcibly before we try to
7691 # execute anything in the user's context, because we always want to
7693 $db_stop = 0; # Compiler warning ...
7694 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
7696 # This variable records how many levels we're nested in debugging. Used
7697 # Used in the debugger prompt, and in determining whether it's all over or
7699 $level = 0; # Level of recursive debugging
7701 # "Triggers bug (?) in perl if we postpone this until runtime."
7702 # XXX No details on this yet, or whether we should fix the bug instead
7703 # of work around it. Stay tuned.
7704 @postponed = @stack = (0);
7706 # Used to track the current stack depth using the auto-stacked-variable
7708 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
7710 # Don't print return values on exiting a subroutine.
7713 # No extry/exit tracing.
7718 BEGIN { $^W = $ini_warn; } # Switch warnings back
7720 =head1 READLINE SUPPORT - COMPLETION FUNCTION
7724 C<readline> support - adds command completion to basic C<readline>.
7726 Returns a list of possible completions to C<readline> when invoked. C<readline>
7727 will print the longest common substring following the text already entered.
7729 If there is only a single possible completion, C<readline> will use it in full.
7731 This code uses C<map> and C<grep> heavily to create lists of possible
7732 completion. Think LISP in this section.
7738 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
7739 # $text is the text to be completed.
7740 # $line is the incoming line typed by the user.
7741 # $start is the start of the text to be completed in the incoming line.
7742 my ($text, $line, $start) = @_;
7744 # Save the initial text.
7745 # The search pattern is current package, ::, extract the next qualifier
7746 # Prefix and pack are set to undef.
7747 my ($itext, $search, $prefix, $pack) =
7748 ($text, "^\Q${'package'}::\E([^:]+)\$");
7750 =head3 C<b postpone|compile>
7754 =item * Find all the subroutines that might match in this package
7756 =item * Add "postpone", "load", and "compile" as possibles (we may be completing the keyword itself
7758 =item * Include all the rest of the subs that are known
7760 =item * C<grep> out the ones that match the text we have so far
7762 =item * Return this as the list of possible completions
7766 return sort grep /^\Q$text/, (keys %sub),
7767 qw(postpone load compile), # subroutines
7768 (map { /$search/ ? ($1) : () } keys %sub)
7769 if (substr $line, 0, $start) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
7773 Get all the possible files from @INC as it currently stands and
7774 select the ones that match the text so far.
7778 return sort grep /^\Q$text/, values %INC # files
7779 if (substr $line, 0, $start) =~ /^\|*b\s+load\s+$/;
7781 =head3 C<V> (list variable) and C<m> (list modules)
7783 There are two entry points for these commands:
7785 =head4 Unqualified package names
7787 Get the top-level packages and grab everything that matches the text
7788 so far. For each match, recursively complete the partial packages to
7789 get all possible matching packages. Return this sorted list.
7793 return sort map { ($_, db_complete($_ . "::", "V ", 2)) }
7794 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
7795 if (substr $line, 0, $start) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
7797 =head4 Qualified package names
7799 Take a partially-qualified package and find all subpackages for it
7800 by getting all the subpackages for the package so far, matching all
7801 the subpackages against the text, and discarding all of them which
7802 start with 'main::'. Return this list.
7806 return sort map { ($_, db_complete($_ . "::", "V ", 2)) }
7807 grep !/^main::/, grep /^\Q$text/,
7808 map { /^(.*)::$/ ? ($prefix . "::$1") : () } keys %{ $prefix . '::' }
7809 if (substr $line, 0, $start) =~ /^\|*[Vm]\s+$/
7810 and $text =~ /^(.*[^:])::?(\w*)$/
7813 =head3 C<f> - switch files
7815 Here, we want to get a fully-qualified filename for the C<f> command.
7820 =item 1. The original source file itself
7822 =item 2. A file from C<@INC>
7824 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
7828 if ($line =~ /^\|*f\s+(.*)/) { # Loaded files
7829 # We might possibly want to switch to an eval (which has a "filename"
7830 # like '(eval 9)'), so we may need to clean up the completion text
7831 # before proceeding.
7832 $prefix = length($1) - length($text);
7837 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
7838 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
7839 out of C<%main::>, add the initial source file, and extract the ones that
7840 match the completion text so far.
7845 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, (keys %main::),
7847 } ## end if ($line =~ /^\|*f\s+(.*)/)
7849 =head3 Subroutine name completion
7851 We look through all of the defined subs (the keys of C<%sub>) and
7852 return both all the possible matches to the subroutine name plus
7853 all the matches qualified to the current package.
7857 if ((substr $text, 0, 1) eq '&') { # subroutines
7858 $text = substr $text, 1;
7860 return sort map "$prefix$_", grep /^\Q$text/, (keys %sub),
7862 map { /$search/ ? ($1) : () }
7865 } ## end if ((substr $text, 0, ...
7867 =head3 Scalar,array, and hash completion: partially qualified package
7869 Much like the above, except we have to do a little more cleanup:
7875 if ($text =~ /^[\$@%](.*)::(.*)/) { # symbols in a package
7879 =item * Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
7883 $pack = ($1 eq 'main' ? '' : $1) . '::';
7887 =item * Figure out the prefix vs. what needs completing.
7891 $prefix = (substr $text, 0, 1) . $1 . '::';
7896 =item * Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
7900 my @out = map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
7905 =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.
7909 if (@out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext) {
7910 return db_complete($out[0], $line, $start);
7913 # Return the list of possibles.
7916 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
7922 =head3 Symbol completion: current package or package C<main>.
7929 if ($text =~ /^[\$@%]/) { # symbols (in $package + packages in main)
7933 =item * If it's C<main>, delete main to just get C<::> leading.
7937 $pack = ($package eq 'main' ? '' : $package) . '::';
7941 =item * We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
7944 $prefix = substr $text, 0, 1;
7945 $text = substr $text, 1;
7949 =item * If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
7953 my @out = map "$prefix$_", grep /^\Q$text/,
7954 (grep /^_?[a-zA-Z]/, keys %$pack),
7955 ($pack eq '::' ? () : (grep /::$/, keys %::));
7957 =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.
7963 if (@out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext) {
7964 return db_complete($out[0], $line, $start);
7967 # Return the list of possibles.
7969 } ## end if ($text =~ /^[\$@%]/)
7973 We use C<option_val()> to look up the current value of the option. If there's
7974 only a single value, we complete the command in such a way that it is a
7975 complete command for setting the option in question. If there are multiple
7976 possible values, we generate a command consisting of the option plus a trailing
7977 question mark, which, if executed, will list the current value of the option.
7981 # Say, didn't the option command's character change?)
7982 # XXX Yes it did. Fix the following pattern match to correct the problem.
7983 # XXX This is a bug.
7984 if ((substr $line, 0, $start) =~ /^\|*O\b.*\s$/) { # Options after a space
7985 # We look for the text to be matched in the list of possible options,
7986 # and fetch the current value.
7987 my @out = grep /^\Q$text/, @options;
7988 my $val = option_val($out[0], undef);
7990 # Set up a 'query option's value' command.
7992 if (not defined $val or $val =~ /[\n\r]/) {
7993 # There's really nothing else we can do.
7996 # We have a value. Create a proper option-setting command.
7997 elsif ($val =~ /\s/) {
7998 # XXX This may be an extraneous variable.
8001 # We'll want to quote the string (because of the embedded
8002 # whtespace), but we want to make sure we don't end up with
8003 # mismatched quote characters. We try several possibilities.
8004 foreach $l (split //, qq/\"\'\#\|/) {
8005 # If we didn't find this quote character in the value,
8006 # quote it using this quote character.
8007 $out = "$l$val$l ", last if (index $val, $l) == -1;
8009 } ## end elsif ($val =~ /\s/)
8011 # Don't need any quotes.
8016 # If there were multiple possible values, return '? ', which
8017 # makes the command into a query command. If there was just one,
8018 # have readline append that.
8019 $rl_attribs->{completer_terminator_character} =
8020 (@out == 1 ? $out : '? ');
8022 # Return list of possibilities.
8024 } ## end if ((substr $line, 0, ...
8026 =head3 Filename completion
8028 For entering filenames. We simply call C<readline>'s C<filename_list()>
8029 method with the completion text to get the possible completions.
8033 return $term->filename_list($text); # filenames
8035 } ## end sub db_complete
8037 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
8039 Functions that possibly ought to be somewhere else.
8049 print $OUT "Use `q' to quit or `R' to restart. `h q' for details.\n";
8054 If we have $ini_pids, save it in the environment; else remove it from the
8055 environment. Used by the C<R> (restart) command.
8060 if (defined($ini_pids)) {
8061 $ENV{PERLDB_PIDS} = $ini_pids;
8064 delete($ENV{PERLDB_PIDS});
8066 } ## end sub clean_ENV
8068 =head1 END PROCESSING - THE C<END> BLOCK
8070 Come here at the very end of processing. We want to go into a
8071 loop where we allow the user to enter commands and interact with the
8072 debugger, but we don't want anything else to execute.
8074 First we set the C<$finished> variable, so that some commands that
8075 shouldn't be run after the end of program quit working.
8077 We then figure out whether we're truly done (as in the user entered a C<q>
8078 command, or we finished exection while running nonstop). If we aren't,
8079 we set C<$single> to 1 (causing the debugger to get control again).
8081 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...">
8082 message and returns control to the debugger. Repeat.
8084 When the user finally enters a C<q> command, C<$fall_off_end> is set to
8085 1 and the C<END> block simply exits with C<$single> set to 0 (don't
8086 break, run to completion.).
8091 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
8092 $fall_off_end = 1 unless $inhibit_exit;
8094 # Do not stop in at_exit() and destructors on exit:
8095 $DB::single = !$fall_off_end && !$runnonstop;
8096 DB::fake::at_exit() unless $fall_off_end or $runnonstop;
8099 =head1 PRE-5.8 COMMANDS
8101 Some of the commands changed function quite a bit in the 5.8 command
8102 realignment, so much so that the old code had to be replaced completely.
8103 Because we wanted to retain the option of being able to go back to the
8104 former command set, we moved the old code off to this section.
8106 There's an awful lot of duplicated code here. We've duplicated the
8107 comments to keep things clear.
8111 Does nothing. Used to 'turn off' commands.
8115 sub cmd_pre580_null {
8120 =head2 Old C<a> command.
8122 This version added actions if you supplied them, and deleted them
8131 # Argument supplied. Add the action.
8132 if ($cmd =~ /^(\d*)\s*(.*)/) {
8134 # If the line isn't there, use the current line.
8138 # If there is an action ...
8141 # ... but the line isn't breakable, skip it.
8142 if ($dbline[$i] == 0) {
8143 print $OUT "Line $i may not have an action.\n";
8146 # ... and the line is breakable:
8147 # Mark that there's an action in this file.
8148 $had_breakpoints{$filename} |= 2;
8150 # Delete any current action.
8151 $dbline{$i} =~ s/\0[^\0]*//;
8153 # Add the new action, continuing the line as needed.
8154 $dbline{$i} .= "\0" . action($j);
8156 } ## end if (length $j)
8158 # No action supplied.
8160 # Delete the action.
8161 $dbline{$i} =~ s/\0[^\0]*//;
8162 # Mark as having no break or action if nothing's left.
8163 delete $dbline{$i} if $dbline{$i} eq '';
8165 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
8166 } ## end sub cmd_pre580_a
8168 =head2 Old C<b> command
8180 if ($cmd =~ /^load\b\s*(.*)/) {
8186 # b compile|postpone <some sub> [<condition>]
8187 # The interpreter actually traps this one for us; we just put the
8188 # necessary condition in the %postponed hash.
8189 elsif ($cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/) {
8190 # Capture the condition if there is one. Make it true if none.
8191 my $cond = length $3 ? $3 : '1';
8193 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
8194 # if it was 'compile'.
8195 my ($subname, $break) = ($2, $1 eq 'postpone');
8197 # De-Perl4-ify the name - ' separators to ::.
8198 $subname =~ s/\'/::/g;
8200 # Qualify it into the current package unless it's already qualified.
8201 $subname = "${'package'}::" . $subname
8202 unless $subname =~ /::/;
8204 # Add main if it starts with ::.
8205 $subname = "main" . $subname if substr($subname, 0, 2) eq "::";
8207 # Save the break type for this sub.
8208 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
8209 } ## end elsif ($cmd =~ ...
8211 # b <sub name> [<condition>]
8212 elsif ($cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/) {
8214 my $cond = length $2 ? $2 : '1';
8215 &cmd_b_sub($subname, $cond);
8218 # b <line> [<condition>].
8219 elsif ($cmd =~ /^(\d*)\s*(.*)/) {
8220 my $i = $1 || $dbline;
8221 my $cond = length $2 ? $2 : '1';
8222 &cmd_b_line($i, $cond);
8224 } ## end sub cmd_pre580_b
8226 =head2 Old C<D> command.
8228 Delete all breakpoints unconditionally.
8235 if ($cmd =~ /^\s*$/) {
8236 print $OUT "Deleting all breakpoints...\n";
8238 # %had_breakpoints lists every file that had at least one
8241 for $file (keys %had_breakpoints) {
8242 # Switch to the desired file temporarily.
8243 local *dbline = $main::{ '_<' . $file };
8248 # For all lines in this file ...
8249 for ($i = 1 ; $i <= $max ; $i++) {
8250 # If there's a breakpoint or action on this line ...
8251 if (defined $dbline{$i}) {
8252 # ... remove the breakpoint.
8253 $dbline{$i} =~ s/^[^\0]+//;
8254 if ($dbline{$i} =~ s/^\0?$//) {
8255 # Remove the entry altogether if no action is there.
8258 } ## end if (defined $dbline{$i...
8259 } ## end for ($i = 1 ; $i <= $max...
8261 # If, after we turn off the "there were breakpoints in this file"
8262 # bit, the entry in %had_breakpoints for this file is zero,
8263 # we should remove this file from the hash.
8264 if (not $had_breakpoints{$file} &= ~1) {
8265 delete $had_breakpoints{$file};
8267 } ## end for $file (keys %had_breakpoints)
8269 # Kill off all the other breakpoints that are waiting for files that
8270 # haven't been loaded yet.
8272 undef %postponed_file;
8273 undef %break_on_load;
8274 } ## end if ($cmd =~ /^\s*$/)
8275 } ## end sub cmd_pre580_D
8277 =head2 Old C<h> command
8279 Print help. Defaults to printing the long-form help; the 5.8 version
8280 prints the summary by default.
8288 # Print the *right* help, long format.
8289 if ($cmd =~ /^\s*$/) {
8290 print_help($pre580_help);
8293 # 'h h' - explicitly-requested summary.
8294 elsif ($cmd =~ /^h\s*/) {
8295 print_help($pre580_summary);
8298 # Find and print a command's help.
8299 elsif ($cmd =~ /^h\s+(\S.*)$/) {
8300 my $asked = $1; # for proper errmsg
8301 my $qasked = quotemeta($asked); # for searching
8302 # XXX: finds CR but not <CR>
8303 if ($pre580_help =~ /^
8305 (?:[IB]<) # Optional markup
8306 $qasked # The command name
8311 ( # The command help:
8313 (?:[IB]<) # Optional markup
8314 $qasked # The command name
8315 ([\s\S]*?) # Lines starting with tabs
8318 (?!\s)/mgx) # Line not starting with space
8319 # (Next command's help)
8323 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
8327 print_help("B<$asked> is not a debugger command.\n");
8329 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
8330 } ## end sub cmd_pre580_h
8332 =head2 Old C<W> command
8334 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
8342 # Delete all watch expressions.
8344 # No watching is going on.
8346 # Kill all the watch expressions and values.
8347 @to_watch = @old_watch = ();
8350 # Add a watch expression.
8351 elsif ($cmd =~ /^(.*)/s) {
8352 # add it to the list to be watched.
8355 # Get the current value of the expression.
8356 # Doesn't handle expressions returning list values!
8359 $val = (defined $val) ? "'$val'" : 'undef';
8362 push @old_watch, $val;
8364 # We're watching stuff.
8367 } ## end elsif ($cmd =~ /^(.*)/s)
8368 } ## end sub cmd_pre580_W
8370 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
8372 The debugger used to have a bunch of nearly-identical code to handle
8373 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
8374 C<cmd_prepost> unify all this into one set of code to handle the
8375 appropriate actions.
8377 =head2 C<cmd_pre590_prepost>
8379 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
8380 do something destructive. In pre 5.8 debuggers, the default action was to
8381 delete all the actions.
8385 sub cmd_pre590_prepost {
8387 my $line = shift || '*';
8390 return &cmd_prepost( $cmd, $line, $dbline );
8391 } ## end sub cmd_pre590_prepost
8393 =head2 C<cmd_prepost>
8395 Actually does all the handling foe C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
8396 Since the lists of actions are all held in arrays that are pointed to by
8397 references anyway, all we have to do is pick the right array reference and
8398 then use generic code to all, delete, or list actions.
8402 sub cmd_prepost { my $cmd = shift;
8404 # No action supplied defaults to 'list'.
8405 my $line = shift || '?';
8407 # Figure out what to put in the prompt.
8410 # Make sure we have some array or another to address later.
8411 # This means that if ssome reason the tests fail, we won't be
8412 # trying to stash actions or delete them from the wrong place.
8415 # < - Perl code to run before prompt.
8416 if ( $cmd =~ /^\</o ) {
8417 $which = 'pre-perl';
8421 # > - Perl code to run after prompt.
8422 elsif ( $cmd =~ /^\>/o ) {
8423 $which = 'post-perl';
8427 # { - first check for properly-balanced braces.
8428 elsif ( $cmd =~ /^\{/o ) {
8429 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
8431 "$cmd is now a debugger command\nuse `;$cmd' if you mean Perl code\n";
8434 # Properly balanced. Pre-prompt debugger actions.
8436 $which = 'pre-debugger';
8439 } ## end elsif ( $cmd =~ /^\{/o )
8441 # Did we find something that makes sense?
8443 print $OUT "Confused by command: $cmd\n";
8449 if ( $line =~ /^\s*\?\s*$/o ) {
8451 # Nothing there. Complain.
8452 print $OUT "No $which actions.\n";
8455 # List the actions in the selected list.
8456 print $OUT "$which commands:\n";
8457 foreach my $action (@$aref) {
8458 print $OUT "\t$cmd -- $action\n";
8461 } ## end if ( $line =~ /^\s*\?\s*$/o)
8463 # Might be a delete.
8465 if ( length($cmd) == 1 ) {
8466 if ( $line =~ /^\s*\*\s*$/o ) {
8467 # It's a delete. Get rid of the old actions in the
8470 print $OUT "All $cmd actions cleared.\n";
8473 # Replace all the actions. (This is a <, >, or {).
8474 @$aref = action($line);
8476 } ## end if ( length($cmd) == 1)
8477 elsif ( length($cmd) == 2 ) {
8478 # Add the action to the line. (This is a <<, >>, or {{).
8479 push @$aref, action($line);
8482 # <<<, >>>>, {{{{{{ ... something not a command.
8484 "Confused by strange length of $which command($cmd)...\n";
8486 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
8488 } ## end sub cmd_prepost
8493 Contains the C<at_exit> routine that the debugger uses to issue the
8494 C<Debugged program terminated ...> message after the program completes. See
8495 the C<END> block documentation for more details.
8502 "Debugged program terminated. Use `q' to quit or `R' to restart.";
8505 package DB; # Do not trace this 1; below!
projects / p5sagit/p5-mst-13.2.git / blob