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 C<perlfunc>, 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<$some_global> is localized,
61 then altered. When the subroutine returns, Perl automatically undoes the
62 localization, restoring the previous value. Voila, automatic stack management.
64 The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>,
65 which lets the debugger get control inside of C<eval>'ed code. The debugger
66 localizes a saved copy of C<$@> 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<$@> inside C<eval>s which C<eval> other C<eval's>.
71 In any case, watch for this pattern. It occurs fairly often.
75 This is used to cleverly reverse the sense of a logical test depending on
76 the value of an auxiliary variable. For instance, the debugger's C<S>
77 (search for subroutines by pattern) allows you to negate the pattern
80 # Find all non-'foo' subs:
83 Boolean algebra states that the truth table for XOR looks like this:
89 (! not present and no match) --> false, don't print
93 (! not present and matches) --> true, print
97 (! present and no match) --> true, print
101 (! present and matches) --> false, don't print
105 As you can see, the first pair applies when C<!> isn't supplied, and
106 the second pair applies when it isn't. The XOR simply allows us to
107 compact a more complicated if-then-elseif-else into a more elegant
108 (but perhaps overly clever) single test. After all, it needed this
111 =head2 FLAGS, FLAGS, FLAGS
113 There is a certain C programming legacy in the debugger. Some variables,
114 such as C<$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 following 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
494 # Debugger for Perl 5.00x; perl5db.pl patch level:
497 $header = "perl5db.pl version $VERSION";
499 =head1 DEBUGGER ROUTINES
503 This function replaces straight C<eval()> inside the debugger; it simplifies
504 the process of evaluating code in the user's context.
506 The code to be evaluated is passed via the package global variable
507 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
509 We preserve the current settings of X<C<$trace>>, X<C<$single>>, and X<C<$^D>>;
510 add the X<C<$usercontext>> (that's the preserved values of C<$@>, C<$!>,
511 C<$^E>, C<$,>, C<$/>, C<$\>, and C<$^W>, grabbed when C<DB::DB> got control,
512 and the user's current package) and a add a newline before we do the C<eval()>.
513 This causes the proper context to be used when the eval is actually done.
514 Afterward, we restore C<$trace>, C<$single>, and C<$^D>.
516 Next we need to handle C<$@> without getting confused. We save C<$@> in a
517 local lexical, localize C<$saved[0]> (which is where C<save()> will put
518 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
519 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
520 considered sane by the debugger. If there was an C<eval()> error, we print
521 it on the debugger's output. If X<C<$onetimedump>> is defined, we call
522 X<C<dumpit>> if it's set to 'dump', or X<C<methods>> if it's set to
523 'methods'. Setting it to something else causes the debugger to do the eval
524 but not print the result - handy if you want to do something else with it
525 (the "watch expressions" code does this to get the value of the watch
526 expression but not show it unless it matters).
528 In any case, we then return the list of output from C<eval> to the caller,
529 and unwinding restores the former version of C<$@> in C<@saved> as well
530 (the localization of C<$saved[0]> goes away at the end of this scope).
532 =head3 Parameters and variables influencing execution of DB::eval()
534 C<DB::eval> isn't parameterized in the standard way; this is to keep the
535 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
536 The variables listed below influence C<DB::eval()>'s execution directly.
540 =item C<$evalarg> - the thing to actually be eval'ed
542 =item C<$trace> - Current state of execution tracing (see X<$trace>)
544 =item C<$single> - Current state of single-stepping (see X<$single>)
546 =item C<$onetimeDump> - what is to be displayed after the evaluation
548 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
552 The following variables are altered by C<DB::eval()> during its execution. They
553 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
557 =item C<@res> - used to capture output from actual C<eval>.
559 =item C<$otrace> - saved value of C<$trace>.
561 =item C<$osingle> - saved value of C<$single>.
563 =item C<$od> - saved value of C<$^D>.
565 =item C<$saved[0]> - saved value of C<$@>.
567 =item $\ - for output of C<$@> if there is an evaluation error.
571 =head3 The problem of lexicals
573 The context of C<DB::eval()> presents us with some problems. Obviously,
574 we want to be 'sandboxed' away from the debugger's internals when we do
575 the eval, but we need some way to control how punctuation variables and
576 debugger globals are used.
578 We can't use local, because the code inside C<DB::eval> can see localized
579 variables; and we can't use C<my> either for the same reason. The code
580 in this routine compromises and uses C<my>.
582 After this routine is over, we don't have user code executing in the debugger's
583 context, so we can use C<my> freely.
587 ############################################## Begin lexical danger zone
589 # 'my' variables used here could leak into (that is, be visible in)
590 # the context that the code being evaluated is executing in. This means that
591 # the code could modify the debugger's variables.
593 # Fiddling with the debugger's context could be Bad. We insulate things as
598 # 'my' would make it visible from user code
599 # but so does local! --tchrist
600 # Remember: this localizes @DB::res, not @main::res.
603 # Try to keep the user code from messing with us. Save these so that
604 # even if the eval'ed code changes them, we can put them back again.
605 # Needed because the user could refer directly to the debugger's
606 # package globals (and any 'my' variables in this containing scope)
607 # inside the eval(), and we want to try to stay safe.
608 local $otrace = $trace;
609 local $osingle = $single;
612 # Untaint the incoming eval() argument.
613 { ($evalarg) = $evalarg =~ /(.*)/s; }
615 # $usercontext built in DB::DB near the comment
616 # "set up the context for DB::eval ..."
617 # Evaluate and save any results.
619 eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
621 # Restore those old values.
627 # Save the current value of $@, and preserve it in the debugger's copy
628 # of the saved precious globals.
631 # Since we're only saving $@, we only have to localize the array element
632 # that it will be stored in.
633 local $saved[0]; # Preserve the old value of $@
636 # Now see whether we need to report an error back to the user.
642 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
643 # are package globals.
644 elsif ($onetimeDump) {
645 if ($onetimeDump eq 'dump') {
646 local $option{dumpDepth} = $onetimedumpDepth
647 if defined $onetimedumpDepth;
650 elsif ($onetimeDump eq 'methods') {
653 } ## end elsif ($onetimeDump)
657 ############################################## End lexical danger zone
659 # After this point it is safe to introduce lexicals
660 # The code being debugged will be executing in its own context, and
661 # can't see the inside of the debugger.
663 # However, one should not overdo it: leave as much control from outside as
664 # possible. If you make something a lexical, it's not going to be addressable
665 # from outside the debugger even if you know its name.
667 # This file is automatically included if you do perl -d.
668 # It's probably not useful to include this yourself.
670 # Before venturing further into these twisty passages, it is
671 # wise to read the perldebguts man page or risk the ire of dragons.
673 # (It should be noted that perldebguts will tell you a lot about
674 # the underlying mechanics of how the debugger interfaces into the
675 # Perl interpreter, but not a lot about the debugger itself. The new
676 # comments in this code try to address this problem.)
678 # Note that no subroutine call is possible until &DB::sub is defined
679 # (for subroutines defined outside of the package DB). In fact the same is
680 # true if $deep is not defined.
682 # $Log: perldb.pl,v $
684 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
686 # modified Perl debugger, to be run from Emacs in perldb-mode
687 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
688 # Johan Vromans -- upgrade to 4.0 pl 10
689 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
691 # (We have made efforts to clarify the comments in the change log
692 # in other places; some of them may seem somewhat obscure as they
693 # were originally written, and explaining them away from the code
694 # in question seems conterproductive.. -JM)
696 ########################################################################
698 # + A lot of things changed after 0.94. First of all, core now informs
699 # debugger about entry into XSUBs, overloaded operators, tied operations,
700 # BEGIN and END. Handy with `O f=2'.
701 # + This can make debugger a little bit too verbose, please be patient
702 # and report your problems promptly.
703 # + Now the option frame has 3 values: 0,1,2. XXX Document!
704 # + Note that if DESTROY returns a reference to the object (or object),
705 # the deletion of data may be postponed until the next function call,
706 # due to the need to examine the return value.
709 # + `v' command shows versions.
712 # + `v' command shows version of readline.
713 # primitive completion works (dynamic variables, subs for `b' and `l',
714 # options). Can `p %var'
715 # + Better help (`h <' now works). New commands <<, >>, {, {{.
716 # {dump|print}_trace() coded (to be able to do it from <<cmd).
717 # + `c sub' documented.
718 # + At last enough magic combined to stop after the end of debuggee.
719 # + !! should work now (thanks to Emacs bracket matching an extra
720 # `]' in a regexp is caught).
721 # + `L', `D' and `A' span files now (as documented).
722 # + Breakpoints in `require'd code are possible (used in `R').
723 # + Some additional words on internal work of debugger.
724 # + `b load filename' implemented.
725 # + `b postpone subr' implemented.
726 # + now only `q' exits debugger (overwritable on $inhibit_exit).
727 # + When restarting debugger breakpoints/actions persist.
728 # + Buglet: When restarting debugger only one breakpoint/action per
729 # autoloaded function persists.
731 # Changes: 0.97: NonStop will not stop in at_exit().
732 # + Option AutoTrace implemented.
733 # + Trace printed differently if frames are printed too.
734 # + new `inhibitExit' option.
735 # + printing of a very long statement interruptible.
736 # Changes: 0.98: New command `m' for printing possible methods
737 # + 'l -' is a synonym for `-'.
738 # + Cosmetic bugs in printing stack trace.
739 # + `frame' & 8 to print "expanded args" in stack trace.
740 # + Can list/break in imported subs.
741 # + new `maxTraceLen' option.
742 # + frame & 4 and frame & 8 granted.
744 # + nonstoppable lines do not have `:' near the line number.
745 # + `b compile subname' implemented.
746 # + Will not use $` any more.
747 # + `-' behaves sane now.
748 # Changes: 0.99: Completion for `f', `m'.
749 # + `m' will remove duplicate names instead of duplicate functions.
750 # + `b load' strips trailing whitespace.
751 # completion ignores leading `|'; takes into account current package
752 # when completing a subroutine name (same for `l').
753 # Changes: 1.07: Many fixed by tchrist 13-March-2000
755 # + Added bare minimal security checks on perldb rc files, plus
756 # comments on what else is needed.
757 # + Fixed the ornaments that made "|h" completely unusable.
758 # They are not used in print_help if they will hurt. Strip pod
759 # if we're paging to less.
760 # + Fixed mis-formatting of help messages caused by ornaments
761 # to restore Larry's original formatting.
762 # + Fixed many other formatting errors. The code is still suboptimal,
763 # and needs a lot of work at restructuring. It's also misindented
765 # + Fixed bug where trying to look at an option like your pager
767 # + Fixed some $? processing. Note: if you use csh or tcsh, you will
768 # lose. You should consider shell escapes not using their shell,
769 # or else not caring about detailed status. This should really be
770 # unified into one place, too.
771 # + Fixed bug where invisible trailing whitespace on commands hoses you,
772 # tricking Perl into thinking you weren't calling a debugger command!
773 # + Fixed bug where leading whitespace on commands hoses you. (One
774 # suggests a leading semicolon or any other irrelevant non-whitespace
775 # to indicate literal Perl code.)
776 # + Fixed bugs that ate warnings due to wrong selected handle.
777 # + Fixed a precedence bug on signal stuff.
778 # + Fixed some unseemly wording.
779 # + Fixed bug in help command trying to call perl method code.
780 # + Fixed to call dumpvar from exception handler. SIGPIPE killed us.
782 # + Added some comments. This code is still nasty spaghetti.
783 # + Added message if you clear your pre/post command stacks which was
784 # very easy to do if you just typed a bare >, <, or {. (A command
785 # without an argument should *never* be a destructive action; this
786 # API is fundamentally screwed up; likewise option setting, which
787 # is equally buggered.)
788 # + Added command stack dump on argument of "?" for >, <, or {.
789 # + Added a semi-built-in doc viewer command that calls man with the
790 # proper %Config::Config path (and thus gets caching, man -k, etc),
791 # or else perldoc on obstreperous platforms.
792 # + Added to and rearranged the help information.
793 # + Detected apparent misuse of { ... } to declare a block; this used
794 # to work but now is a command, and mysteriously gave no complaint.
796 # Changes: 1.08: Apr 25, 2001 Jon Eveland <jweveland@yahoo.com>
798 # + This patch to perl5db.pl cleans up formatting issues on the help
799 # summary (h h) screen in the debugger. Mostly columnar alignment
800 # issues, plus converted the printed text to use all spaces, since
801 # tabs don't seem to help much here.
803 # Changes: 1.09: May 19, 2001 Ilya Zakharevich <ilya@math.ohio-state.edu>
804 # Minor bugs corrected;
805 # + Support for auto-creation of new TTY window on startup, either
806 # unconditionally, or if started as a kid of another debugger session;
807 # + New `O'ption CreateTTY
808 # I<CreateTTY> bits control attempts to create a new TTY on events:
810 # 2: debugger is started inside debugger
812 # + Code to auto-create a new TTY window on OS/2 (currently one
813 # extra window per session - need named pipes to have more...);
814 # + Simplified interface for custom createTTY functions (with a backward
815 # compatibility hack); now returns the TTY name to use; return of ''
816 # means that the function reset the I/O handles itself;
817 # + Better message on the semantic of custom createTTY function;
818 # + Convert the existing code to create a TTY into a custom createTTY
820 # + Consistent support for TTY names of the form "TTYin,TTYout";
821 # + Switch line-tracing output too to the created TTY window;
822 # + make `b fork' DWIM with CORE::GLOBAL::fork;
823 # + High-level debugger API cmd_*():
824 # cmd_b_load($filenamepart) # b load filenamepart
825 # cmd_b_line($lineno [, $cond]) # b lineno [cond]
826 # cmd_b_sub($sub [, $cond]) # b sub [cond]
827 # cmd_stop() # Control-C
828 # cmd_d($lineno) # d lineno (B)
829 # The cmd_*() API returns FALSE on failure; in this case it outputs
830 # the error message to the debugging output.
831 # + Low-level debugger API
832 # break_on_load($filename) # b load filename
833 # @files = report_break_on_load() # List files with load-breakpoints
834 # breakable_line_in_filename($name, $from [, $to])
835 # # First breakable line in the
836 # # range $from .. $to. $to defaults
837 # # to $from, and may be less than
839 # breakable_line($from [, $to]) # Same for the current file
840 # break_on_filename_line($name, $lineno [, $cond])
841 # # Set breakpoint,$cond defaults to
843 # break_on_filename_line_range($name, $from, $to [, $cond])
844 # # As above, on the first
845 # # breakable line in range
846 # break_on_line($lineno [, $cond]) # As above, in the current file
847 # break_subroutine($sub [, $cond]) # break on the first breakable line
848 # ($name, $from, $to) = subroutine_filename_lines($sub)
849 # # The range of lines of the text
850 # The low-level API returns TRUE on success, and die()s on failure.
852 # Changes: 1.10: May 23, 2001 Daniel Lewart <d-lewart@uiuc.edu>
854 # + Fixed warnings generated by "perl -dWe 42"
855 # + Corrected spelling errors
856 # + Squeezed Help (h) output into 80 columns
858 # Changes: 1.11: May 24, 2001 David Dyck <dcd@tc.fluke.com>
859 # + Made "x @INC" work like it used to
861 # Changes: 1.12: May 24, 2001 Daniel Lewart <d-lewart@uiuc.edu>
862 # + Fixed warnings generated by "O" (Show debugger options)
863 # + Fixed warnings generated by "p 42" (Print expression)
864 # Changes: 1.13: Jun 19, 2001 Scott.L.Miller@compaq.com
865 # + Added windowSize option
866 # Changes: 1.14: Oct 9, 2001 multiple
867 # + Clean up after itself on VMS (Charles Lane in 12385)
868 # + Adding "@ file" syntax (Peter Scott in 12014)
869 # + Debug reloading selfloaded stuff (Ilya Zakharevich in 11457)
870 # + $^S and other debugger fixes (Ilya Zakharevich in 11120)
871 # + Forgot a my() declaration (Ilya Zakharevich in 11085)
872 # Changes: 1.15: Nov 6, 2001 Michael G Schwern <schwern@pobox.com>
873 # + Updated 1.14 change log
874 # + Added *dbline explainatory comments
875 # + Mentioning perldebguts man page
876 # Changes: 1.16: Feb 15, 2002 Mark-Jason Dominus <mjd@plover.com>
877 # + $onetimeDump improvements
878 # Changes: 1.17: Feb 20, 2002 Richard Foley <richard.foley@rfi.net>
879 # Moved some code to cmd_[.]()'s for clarity and ease of handling,
880 # rationalised the following commands and added cmd_wrapper() to
881 # enable switching between old and frighteningly consistent new
882 # behaviours for diehards: 'o CommandSet=pre580' (sigh...)
883 # a(add), A(del) # action expr (added del by line)
884 # + b(add), B(del) # break [line] (was b,D)
885 # + w(add), W(del) # watch expr (was W,W)
886 # # added del by expr
887 # + h(summary), h h(long) # help (hh) (was h h,h)
888 # + m(methods), M(modules) # ... (was m,v)
889 # + o(option) # lc (was O)
890 # + v(view code), V(view Variables) # ... (was w,V)
891 # Changes: 1.18: Mar 17, 2002 Richard Foley <richard.foley@rfi.net>
892 # + fixed missing cmd_O bug
893 # Changes: 1.19: Mar 29, 2002 Spider Boardman
894 # + Added missing local()s -- DB::DB is called recursively.
895 # Changes: 1.20: Feb 17, 2003 Richard Foley <richard.foley@rfi.net>
896 # + pre'n'post commands no longer trashed with no args
897 # + watch val joined out of eval()
898 # Changes: 1.21: Jun 04, 2003 Joe McMahon <mcmahon@ibiblio.org>
899 # + Added comments and reformatted source. No bug fixes/enhancements.
900 # + Includes cleanup by Robin Barker and Jarkko Hietaniemi.
901 # Changes: 1.22 Jun 09, 2003 Alex Vandiver <alexmv@MIT.EDU>
902 # + Flush stdout/stderr before the debugger prompt is printed.
903 # Changes: 1.23: Dec 21, 2003 Dominique Quatravaux
904 # + Fix a side-effect of bug #24674 in the perl debugger ("odd taint bug")
905 # Changes: 1.24: Mar 03, 2004 Richard Foley <richard.foley@rfi.net>
906 # + Added command to save all debugger commands for sourcing later.
907 # + Added command to display parent inheritence tree of given class.
908 # + Fixed minor newline in history bug.
909 # Changes: 1.25 (again :)
910 # + unfork the 5.8.x and 5.9.x debuggers.
911 # + Richard Foley and Joe McMahon
912 ####################################################################
914 =head1 DEBUGGER INITIALIZATION
916 The debugger starts up in phases.
920 First, it initializes the environment it wants to run in: turning off
921 warnings during its own compilation, defining variables which it will need
922 to avoid warnings later, setting itself up to not exit when the program
923 terminates, and defaulting to printing return values for the C<r> command.
927 # Needed for the statement after exec():
929 # This BEGIN block is simply used to switch off warnings during debugger
930 # compiliation. Probably it would be better practice to fix the warnings,
931 # but this is how it's done at the moment.
937 } # Switch compilation warnings off until another BEGIN.
939 # test if assertions are supported and actived:
942 eval "sub asserting_test : assertion {1}; 1";
943 # $ini_assertion = undef => assertions unsupported,
944 # " = 1 => assertions suported
945 # print "\$ini_assertion=$ini_assertion\n";
948 local ($^W) = 0; # Switch run-time warnings off during init.
950 # This would probably be better done with "use vars", but that wasn't around
951 # when this code was originally written. (Neither was "use strict".) And on
952 # the principle of not fiddling with something that was working, this was
955 # These variables control the execution of 'dumpvar.pl'.
957 $dumpvar::arrayDepth,
958 $dumpvar::dumpDBFiles,
959 $dumpvar::dumpPackages,
960 $dumpvar::quoteHighBit,
961 $dumpvar::printUndef,
965 # used to save @ARGV and extract any debugger-related flags.
968 # used to control die() reporting in diesignal()
971 # used to prevent multiple entries to diesignal()
972 # (if for instance diesignal() itself dies)
975 # used to prevent the debugger from running nonstop
981 # Command-line + PERLLIB:
982 # Save the contents of @INC before they are modified elsewhere.
985 # This was an attempt to clear out the previous values of various
986 # trapped errors. Apparently it didn't help. XXX More info needed!
987 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
989 # We set these variables to safe values. We don't want to blindly turn
990 # off warnings, because other packages may still want them.
991 $trace = $signal = $single = 0; # Uninitialized warning suppression
992 # (local $^W cannot help - other packages!).
994 # Default to not exiting when program finishes; print the return
995 # value when the 'r' command is used to return from a subroutine.
996 $inhibit_exit = $option{PrintRet} = 1;
998 =head1 OPTION PROCESSING
1000 The debugger's options are actually spread out over the debugger itself and
1001 C<dumpvar.pl>; some of these are variables to be set, while others are
1002 subs to be called with a value. To try to make this a little easier to
1003 manage, the debugger uses a few data structures to define what options
1004 are legal and how they are to be processed.
1006 First, the C<@options> array defines the I<names> of all the options that
1013 hashDepth arrayDepth dumpDepth
1014 DumpDBFiles DumpPackages DumpReused
1015 compactDump veryCompact quote
1016 HighBit undefPrint globPrint
1017 PrintRet UsageOnl frame
1019 ReadLine NonStop LineInfo
1020 maxTraceLen recallCommand ShellBang
1021 pager tkRunning ornaments
1022 signalLevel warnLevel dieLevel
1023 inhibit_exit ImmediateStop bareStringify
1024 CreateTTY RemotePort windowSize
1025 DollarCaretP OnlyAssertions WarnAssertions
1028 @RememberOnROptions = qw(DollarCaretP OnlyAssertions);
1032 Second, C<optionVars> lists the variables that each option uses to save its
1038 hashDepth => \$dumpvar::hashDepth,
1039 arrayDepth => \$dumpvar::arrayDepth,
1040 CommandSet => \$CommandSet,
1041 DumpDBFiles => \$dumpvar::dumpDBFiles,
1042 DumpPackages => \$dumpvar::dumpPackages,
1043 DumpReused => \$dumpvar::dumpReused,
1044 HighBit => \$dumpvar::quoteHighBit,
1045 undefPrint => \$dumpvar::printUndef,
1046 globPrint => \$dumpvar::globPrint,
1047 UsageOnly => \$dumpvar::usageOnly,
1048 CreateTTY => \$CreateTTY,
1049 bareStringify => \$dumpvar::bareStringify,
1051 AutoTrace => \$trace,
1052 inhibit_exit => \$inhibit_exit,
1053 maxTraceLen => \$maxtrace,
1054 ImmediateStop => \$ImmediateStop,
1055 RemotePort => \$remoteport,
1056 windowSize => \$window,
1057 WarnAssertions => \$warnassertions,
1062 Third, C<%optionAction> defines the subroutine to be called to process each
1068 compactDump => \&dumpvar::compactDump,
1069 veryCompact => \&dumpvar::veryCompact,
1070 quote => \&dumpvar::quote,
1073 ReadLine => \&ReadLine,
1074 NonStop => \&NonStop,
1075 LineInfo => \&LineInfo,
1076 recallCommand => \&recallCommand,
1077 ShellBang => \&shellBang,
1079 signalLevel => \&signalLevel,
1080 warnLevel => \&warnLevel,
1081 dieLevel => \&dieLevel,
1082 tkRunning => \&tkRunning,
1083 ornaments => \&ornaments,
1084 RemotePort => \&RemotePort,
1085 DollarCaretP => \&DollarCaretP,
1086 OnlyAssertions=> \&OnlyAssertions,
1091 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1096 # Note that this list is not complete: several options not listed here
1097 # actually require that dumpvar.pl be loaded for them to work, but are
1098 # not in the table. A subsequent patch will correct this problem; for
1099 # the moment, we're just recommenting, and we are NOT going to change
1102 compactDump => 'dumpvar.pl',
1103 veryCompact => 'dumpvar.pl',
1104 quote => 'dumpvar.pl',
1109 There are a number of initialization-related variables which can be set
1110 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1111 variable. These are:
1115 =item C<$rl> - readline control XXX needs more explanation
1117 =item C<$warnLevel> - whether or not debugger takes over warning handling
1119 =item C<$dieLevel> - whether or not debugger takes over die handling
1121 =item C<$signalLevel> - whether or not debugger takes over signal handling
1123 =item C<$pre> - preprompt actions (array reference)
1125 =item C<$post> - postprompt actions (array reference)
1129 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1131 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1137 # These guys may be defined in $ENV{PERL5DB} :
1138 $rl = 1 unless defined $rl;
1139 $warnLevel = 1 unless defined $warnLevel;
1140 $dieLevel = 1 unless defined $dieLevel;
1141 $signalLevel = 1 unless defined $signalLevel;
1142 $pre = [] unless defined $pre;
1143 $post = [] unless defined $post;
1144 $pretype = [] unless defined $pretype;
1145 $CreateTTY = 3 unless defined $CreateTTY;
1146 $CommandSet = '580' unless defined $CommandSet;
1150 The default C<die>, C<warn>, and C<signal> handlers are set up.
1154 warnLevel($warnLevel);
1155 dieLevel($dieLevel);
1156 signalLevel($signalLevel);
1160 The pager to be used is needed next. We try to get it from the
1161 environment first. if it's not defined there, we try to find it in
1162 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1163 then call the C<pager()> function to save the pager name.
1167 # This routine makes sure $pager is set up so that '|' can use it.
1169 # If PAGER is defined in the environment, use it.
1173 # If not, see if Config.pm defines it.
1174 : eval { require Config } && defined $Config::Config{pager}
1175 ? $Config::Config{pager}
1177 # If not, fall back to 'more'.
1180 unless defined $pager;
1184 We set up the command to be used to access the man pages, the command
1185 recall character ("!" unless otherwise defined) and the shell escape
1186 character ("!" unless otherwise defined). Yes, these do conflict, and
1187 neither works in the debugger at the moment.
1193 # Set up defaults for command recall and shell escape (note:
1194 # these currently don't work in linemode debugging).
1195 &recallCommand("!") unless defined $prc;
1196 &shellBang("!") unless defined $psh;
1200 We then set up the gigantic string containing the debugger help.
1201 We also set the limit on the number of arguments we'll display during a
1208 # If we didn't get a default for the length of eval/stack trace args,
1210 $maxtrace = 400 unless defined $maxtrace;
1212 =head2 SETTING UP THE DEBUGGER GREETING
1214 The debugger 'greeting' helps to inform the user how many debuggers are
1215 running, and whether the current debugger is the primary or a child.
1217 If we are the primary, we just hang onto our pid so we'll have it when
1218 or if we start a child debugger. If we are a child, we'll set things up
1219 so we'll have a unique greeting and so the parent will give us our own
1222 We save the current contents of the C<PERLDB_PIDS> environment variable
1223 because we mess around with it. We'll also need to hang onto it because
1224 we'll need it if we restart.
1226 Child debuggers make a label out of the current PID structure recorded in
1227 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1228 yet so the parent will give them one later via C<resetterm()>.
1232 # Save the current contents of the environment; we're about to
1233 # much with it. We'll need this if we have to restart.
1234 $ini_pids = $ENV{PERLDB_PIDS};
1236 if (defined $ENV{PERLDB_PIDS}) {
1237 # We're a child. Make us a label out of the current PID structure
1238 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1239 # a term yet so the parent will give us one later via resetterm().
1240 $pids = "[$ENV{PERLDB_PIDS}]";
1241 $ENV{PERLDB_PIDS} .= "->$$";
1243 } ## end if (defined $ENV{PERLDB_PIDS...
1245 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1246 # child debugger, and mark us as the parent, so we'll know to set up
1247 # more TTY's is we have to.
1248 $ENV{PERLDB_PIDS} = "$$";
1255 # Sets up $emacs as a synonym for $slave_editor.
1256 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1258 =head2 READING THE RC FILE
1260 The debugger will read a file of initialization options if supplied. If
1261 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1265 # As noted, this test really doesn't check accurately that the debugger
1266 # is running at a terminal or not.
1268 if (-e "/dev/tty") { # this is the wrong metric!
1272 $rcfile = "perldb.ini";
1277 The debugger does a safety test of the file to be read. It must be owned
1278 either by the current user or root, and must only be writable by the owner.
1282 # This wraps a safety test around "do" to read and evaluate the init file.
1284 # This isn't really safe, because there's a race
1285 # between checking and opening. The solution is to
1286 # open and fstat the handle, but then you have to read and
1287 # eval the contents. But then the silly thing gets
1288 # your lexical scope, which is unfortunate at best.
1292 # Just exactly what part of the word "CORE::" don't you understand?
1293 local $SIG{__WARN__};
1294 local $SIG{__DIE__};
1296 unless (is_safe_file($file)) {
1297 CORE::warn <<EO_GRIPE;
1298 perldb: Must not source insecure rcfile $file.
1299 You or the superuser must be the owner, and it must not
1300 be writable by anyone but its owner.
1303 } ## end unless (is_safe_file($file...
1306 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1307 } ## end sub safe_do
1309 # This is the safety test itself.
1311 # Verifies that owner is either real user or superuser and that no
1312 # one but owner may write to it. This function is of limited use
1313 # when called on a path instead of upon a handle, because there are
1314 # no guarantees that filename (by dirent) whose file (by ino) is
1315 # eventually accessed is the same as the one tested.
1316 # Assumes that the file's existence is not in doubt.
1319 stat($path) || return; # mysteriously vaporized
1320 my ($dev, $ino, $mode, $nlink, $uid, $gid) = stat(_);
1322 return 0 if $uid != 0 && $uid != $<;
1323 return 0 if $mode & 022;
1325 } ## end sub is_safe_file
1327 # If the rcfile (whichever one we decided was the right one to read)
1328 # exists, we safely do it.
1330 safe_do("./$rcfile");
1332 # If there isn't one here, try the user's home directory.
1333 elsif (defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile") {
1334 safe_do("$ENV{HOME}/$rcfile");
1336 # Else try the login directory.
1337 elsif (defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile") {
1338 safe_do("$ENV{LOGDIR}/$rcfile");
1341 # If the PERLDB_OPTS variable has options in it, parse those out next.
1342 if (defined $ENV{PERLDB_OPTS}) {
1343 parse_options($ENV{PERLDB_OPTS});
1348 The last thing we do during initialization is determine which subroutine is
1349 to be used to obtain a new terminal when a new debugger is started. Right now,
1350 the debugger only handles X Windows and OS/2.
1354 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1355 # Works if you're running an xterm or xterm-like window, or you're on
1356 # OS/2. This may need some expansion: for instance, this doesn't handle
1357 # OS X Terminal windows.
1360 if (not defined &get_fork_TTY
1361 and defined $ENV{TERM}
1363 and $ENV{TERM} eq 'xterm'
1364 and defined $ENV{WINDOWID}
1366 and defined $ENV{DISPLAY})
1368 *get_fork_TTY = \&xterm_get_fork_TTY;
1369 } ## end if (not defined &get_fork_TTY...
1370 elsif ($^O eq 'os2') {
1371 *get_fork_TTY = \&os2_get_fork_TTY;
1373 # untaint $^O, which may have been tainted by the last statement.
1374 # see bug [perl #24674]
1375 $^O =~ m/^(.*)\z/; $^O = $1;
1377 # Here begin the unreadable code. It needs fixing.
1379 =head2 RESTART PROCESSING
1381 This section handles the restart command. When the C<R> command is invoked, it
1382 tries to capture all of the state it can into environment variables, and
1383 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1384 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1385 the R command stuffed into the environment variables.
1387 PERLDB_RESTART - flag only, contains no restart data itself.
1388 PERLDB_HIST - command history, if it's available
1389 PERLDB_ON_LOAD - breakpoints set by the rc file
1390 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1391 PERLDB_VISITED - files that had breakpoints
1392 PERLDB_FILE_... - breakpoints for a file
1393 PERLDB_OPT - active options
1394 PERLDB_INC - the original @INC
1395 PERLDB_PRETYPE - preprompt debugger actions
1396 PERLDB_PRE - preprompt Perl code
1397 PERLDB_POST - post-prompt Perl code
1398 PERLDB_TYPEAHEAD - typeahead captured by readline()
1400 We chug through all these variables and plug the values saved in them
1401 back into the appropriate spots in the debugger.
1405 if (exists $ENV{PERLDB_RESTART}) {
1406 # We're restarting, so we don't need the flag that says to restart anymore.
1407 delete $ENV{PERLDB_RESTART};
1409 @hist = get_list('PERLDB_HIST');
1410 %break_on_load = get_list("PERLDB_ON_LOAD");
1411 %postponed = get_list("PERLDB_POSTPONE");
1413 # restore breakpoints/actions
1414 my @had_breakpoints = get_list("PERLDB_VISITED");
1415 for (0 .. $#had_breakpoints) {
1416 my %pf = get_list("PERLDB_FILE_$_");
1417 $postponed_file{ $had_breakpoints[$_] } = \%pf if %pf;
1421 my %opt = get_list("PERLDB_OPT");
1423 while (($opt, $val) = each %opt) {
1424 $val =~ s/[\\\']/\\$1/g;
1425 parse_options("$opt'$val'");
1428 # restore original @INC
1429 @INC = get_list("PERLDB_INC");
1432 # return pre/postprompt actions and typeahead buffer
1433 $pretype = [get_list("PERLDB_PRETYPE")];
1434 $pre = [get_list("PERLDB_PRE")];
1435 $post = [get_list("PERLDB_POST")];
1436 @typeahead = get_list("PERLDB_TYPEAHEAD", @typeahead);
1437 } ## end if (exists $ENV{PERLDB_RESTART...
1439 =head2 SETTING UP THE TERMINAL
1441 Now, we'll decide how the debugger is going to interact with the user.
1442 If there's no TTY, we set the debugger to run non-stop; there's not going
1443 to be anyone there to enter commands.
1453 If there is a TTY, we have to determine who it belongs to before we can
1454 proceed. If this is a slave editor or graphical debugger (denoted by
1455 the first command-line switch being '-emacs'), we shift this off and
1456 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1461 # Is Perl being run from a slave editor or graphical debugger?
1462 # If so, don't use readline, and set $slave_editor = 1.
1464 ((defined $main::ARGV[0]) and ($main::ARGV[0] eq '-emacs'));
1465 $rl = 0, shift (@main::ARGV) if $slave_editor;
1466 #require Term::ReadLine;
1470 We then determine what the console should be on various systems:
1474 =item * Cygwin - We use C<stdin> instead of a separate device.
1478 if ($^O eq 'cygwin') {
1479 # /dev/tty is binary. use stdin for textmode
1483 =item * Unix - use C</dev/tty>.
1487 elsif (-e "/dev/tty") {
1488 $console = "/dev/tty";
1491 =item * Windows or MSDOS - use C<con>.
1495 elsif ($^O eq 'dos' or -e "con" or $^O eq 'MSWin32') {
1499 =item * MacOS - use C<Dev:Console:Perl Debug> if this is the MPW version; C<Dev:
1500 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.)
1504 elsif ($^O eq 'MacOS') {
1505 if ($MacPerl::Version !~ /MPW/) {
1507 "Dev:Console:Perl Debug"; # Separate window for application
1510 $console = "Dev:Console";
1512 } ## end elsif ($^O eq 'MacOS')
1514 =item * VMS - use C<sys$command>.
1519 # everything else is ...
1520 $console = "sys\$command";
1527 Several other systems don't use a specific console. We C<undef $console>
1528 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1529 with a slave editor, Epoc).
1533 if (($^O eq 'MSWin32') and ($slave_editor or defined $ENV{EMACS})) {
1534 # /dev/tty is binary. use stdin for textmode
1538 if ($^O eq 'NetWare') {
1539 # /dev/tty is binary. use stdin for textmode
1543 # In OS/2, we need to use STDIN to get textmode too, even though
1544 # it pretty much looks like Unix otherwise.
1545 if (defined $ENV{OS2_SHELL} and ($slave_editor or $ENV{WINDOWID}))
1549 # EPOC also falls into the 'got to use STDIN' camp.
1550 if ($^O eq 'epoc') {
1556 If there is a TTY hanging around from a parent, we use that as the console.
1560 $console = $tty if defined $tty;
1562 =head2 SOCKET HANDLING
1564 The debugger is capable of opening a socket and carrying out a debugging
1565 session over the socket.
1567 If C<RemotePort> was defined in the options, the debugger assumes that it
1568 should try to start a debugging session on that port. It builds the socket
1569 and then tries to connect the input and output filehandles to it.
1573 # Handle socket stuff.
1575 if (defined $remoteport) {
1576 # If RemotePort was defined in the options, connect input and output
1579 $OUT = new IO::Socket::INET(
1581 PeerAddr => $remoteport,
1584 if (!$OUT) { die "Unable to connect to remote host: $remoteport\n"; }
1586 } ## end if (defined $remoteport)
1590 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1591 this is probably a situation where multiple debuggers are running (for example,
1592 a backticked command that starts up another debugger). We create a new IN and
1593 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1600 # Two debuggers running (probably a system or a backtick that invokes
1601 # the debugger itself under the running one). create a new IN and OUT
1602 # filehandle, and do the necessary mojo to create a new tty if we
1603 # know how, and we can.
1604 create_IN_OUT(4) if $CreateTTY & 4;
1606 # If we have a console, check to see if there are separate ins and
1607 # outs to open. (They are assumed identiical if not.)
1611 my ($i, $o) = split /,/, $console;
1612 $o = $i unless defined $o;
1613 # read/write on in, or just read, or read on STDIN.
1617 # read/write/create/clobber out, or write/create/clobber out,
1618 # or merge with STDERR, or merge with STDOUT.
1619 open(OUT, "+>$o") ||
1621 open(OUT, ">&STDERR") ||
1622 open(OUT, ">&STDOUT"); # so we don't dongle stdout
1624 } ## end if ($console)
1625 elsif (not defined $console) {
1626 # No console. Open STDIN.
1627 open(IN, "<&STDIN");
1629 # merge with STDERR, or with STDOUT.
1630 open(OUT, ">&STDERR") ||
1631 open(OUT, ">&STDOUT"); # so we don't dongle stdout
1632 $console = 'STDIN/OUT';
1633 } ## end elsif (not defined $console)
1635 # Keep copies of the filehandles so that when the pager runs, it
1636 # can close standard input without clobbering ours.
1637 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1638 } ## end elsif (from if(defined $remoteport))
1640 # Unbuffer DB::OUT. We need to see responses right away.
1641 my $previous = select($OUT);
1642 $| = 1; # for DB::OUT
1645 # Line info goes to debugger output unless pointed elsewhere.
1646 # Pointing elsewhere makes it possible for slave editors to
1647 # keep track of file and position. We have both a filehandle
1648 # and a I/O description to keep track of.
1649 $LINEINFO = $OUT unless defined $LINEINFO;
1650 $lineinfo = $console unless defined $lineinfo;
1653 To finish initialization, we show the debugger greeting,
1654 and then call the C<afterinit()> subroutine if there is one.
1658 # Show the debugger greeting.
1659 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1660 unless ($runnonstop) {
1663 if ($term_pid eq '-1') {
1664 print $OUT "\nDaughter DB session started...\n";
1667 print $OUT "\nLoading DB routines from $header\n";
1670 $slave_editor ? "enabled" : "available", ".\n"
1673 "\nEnter h or `h h' for help, or `$doccmd perldebug' for more help.\n\n";
1674 } ## end else [ if ($term_pid eq '-1')
1675 } ## end unless ($runnonstop)
1676 } ## end else [ if ($notty)
1678 # XXX This looks like a bug to me.
1679 # Why copy to @ARGS and then futz with @args?
1682 # Make sure backslashes before single quotes are stripped out, and
1683 # keep args unless they are numeric (XXX why?)
1685 s/(.*)/'$1'/ unless /^-?[\d.]+$/;
1688 # If there was an afterinit() sub defined, call it. It will get
1689 # executed in our scope, so it can fiddle with debugger globals.
1690 if (defined &afterinit) { # May be defined in $rcfile
1693 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1696 ############################################################ Subroutines
1702 This gigantic subroutine is the heart of the debugger. Called before every
1703 statement, its job is to determine if a breakpoint has been reached, and
1704 stop if so; read commands from the user, parse them, and execute
1705 them, and hen send execution off to the next statement.
1707 Note that the order in which the commands are processed is very important;
1708 some commands earlier in the loop will actually alter the C<$cmd> variable
1709 to create other commands to be executed later. This is all highly "optimized"
1710 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1711 see what's happening in any given command.
1717 # Check for whether we should be running continuously or not.
1718 # _After_ the perl program is compiled, $single is set to 1:
1719 if ($single and not $second_time++) {
1720 # Options say run non-stop. Run until we get an interrupt.
1721 if ($runnonstop) { # Disable until signal
1722 # If there's any call stack in place, turn off single
1723 # stepping into subs throughout the stack.
1724 for ($i = 0 ; $i <= $stack_depth ;) {
1727 # And we are now no longer in single-step mode.
1730 # If we simply returned at this point, we wouldn't get
1731 # the trace info. Fall on through.
1733 } ## end if ($runnonstop)
1735 elsif ($ImmediateStop) {
1736 # We are supposed to stop here; XXX probably a break.
1737 $ImmediateStop = 0; # We've processed it; turn it off
1738 $signal = 1; # Simulate an interrupt to force
1739 # us into the command loop
1741 } ## end if ($single and not $second_time...
1743 # If we're in single-step mode, or an interrupt (real or fake)
1744 # has occurred, turn off non-stop mode.
1745 $runnonstop = 0 if $single or $signal;
1747 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1748 # The code being debugged may have altered them.
1751 # Since DB::DB gets called after every line, we can use caller() to
1752 # figure out where we last were executing. Sneaky, eh? This works because
1753 # caller is returning all the extra information when called from the
1755 local($package, $filename, $line) = caller;
1756 local $filename_ini = $filename;
1758 # set up the context for DB::eval, so it can properly execute
1759 # code on behalf of the user. We add the package in so that the
1760 # code is eval'ed in the proper package (not in the debugger!).
1761 local $usercontext =
1762 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' .
1763 "package $package;";
1765 # Create an alias to the active file magical array to simplify
1767 local(*dbline) = $main::{'_<' . $filename};
1769 # we need to check for pseudofiles on Mac OS (these are files
1770 # not attached to a filename, but instead stored in Dev:Pseudo)
1771 if ($^O eq 'MacOS' && $#dbline < 0) {
1772 $filename_ini = $filename = 'Dev:Pseudo';
1773 *dbline = $main::{'_<' . $filename};
1776 # Last line in the program.
1777 local $max = $#dbline;
1779 # if we have something here, see if we should break.
1780 if ($dbline{$line} && (($stop,$action) = split(/\0/,$dbline{$line}))) {
1781 # Stop if the stop criterion says to just stop.
1785 # It's a conditional stop; eval it in the user's context and
1786 # see if we should stop. If so, remove the one-time sigil.
1788 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1790 $dbline{$line} =~ s/;9($|\0)/$1/;
1792 } ## end if ($dbline{$line} && ...
1794 # Preserve the current stop-or-not, and see if any of the W
1795 # (watch expressions) has changed.
1796 my $was_signal = $signal;
1798 # If we have any watch expressions ...
1800 for (my $n = 0; $n <= $#to_watch; $n++) {
1801 $evalarg = $to_watch[$n];
1802 local $onetimeDump; # Do not output results
1804 # Fix context DB::eval() wants to return an array, but
1805 # we need a scalar here.
1807 join("', '", &eval); # Fix context (&eval is doing array)
1808 $val = ( (defined $val) ? "'$val'" : 'undef' );
1811 if ($val ne $old_watch[$n]) {
1812 # Yep! Show the difference, and fake an interrupt.
1815 Watchpoint $n:\t$to_watch[$n] changed:
1816 old value:\t$old_watch[$n]
1819 $old_watch[$n] = $val;
1820 } ## end if ($val ne $old_watch...
1821 } ## end for (my $n = 0 ; $n <= ...
1822 } ## end if ($trace & 2)
1824 =head2 C<watchfunction()>
1826 C<watchfunction()> is a function that can be defined by the user; it is a
1827 function which will be run on each entry to C<DB::DB>; it gets the
1828 current package, filename, and line as its parameters.
1830 The watchfunction can do anything it likes; it is executing in the
1831 debugger's context, so it has access to all of the debugger's internal
1832 data structures and functions.
1834 C<watchfunction()> can control the debugger's actions. Any of the following
1835 will cause the debugger to return control to the user's program after
1836 C<watchfunction()> executes:
1840 =item * Returning a false value from the C<watchfunction()> itself.
1842 =item * Altering C<$single> to a false value.
1844 =item * Altering C<$signal> to a false value.
1846 =item * Turning off the '4' bit in C<$trace> (this also disables the
1847 check for C<watchfunction()>. This can be done with
1855 # If there's a user-defined DB::watchfunction, call it with the
1856 # current package, filename, and line. The function executes in
1858 if ($trace & 4) { # User-installed watch
1860 if watchfunction($package, $filename, $line)
1863 and not ($trace & ~4);
1864 } ## end if ($trace & 4)
1866 # Pick up any alteration to $signal in the watchfunction, and
1867 # turn off the signal now.
1868 $was_signal = $signal;
1871 =head2 GETTING READY TO EXECUTE COMMANDS
1873 The debugger decides to take control if single-step mode is on, the
1874 C<t> command was entered, or the user generated a signal. If the program
1875 has fallen off the end, we set things up so that entering further commands
1876 won't cause trouble, and we say that the program is over.
1880 # Check to see if we should grab control ($single true,
1881 # trace set appropriately, or we got a signal).
1882 if ($single || ($trace & 1) || $was_signal) {
1883 # Yes, grab control.
1884 if ($slave_editor) {
1885 # Tell the editor to update its position.
1886 $position = "\032\032$filename:$line:0\n";
1887 print_lineinfo($position);
1892 Special check: if we're in package C<DB::fake>, we've gone through the
1893 C<END> block at least once. We set up everything so that we can continue
1894 to enter commands and have a valid context to be in.
1899 elsif ($package eq 'DB::fake') {
1900 # Fallen off the end already.
1903 Debugged program terminated. Use B<q> to quit or B<R> to restart,
1904 use B<O> I<inhibit_exit> to avoid stopping after program termination,
1905 B<h q>, B<h R> or B<h O> to get additional info.
1907 # Set the DB::eval context appropriately.
1910 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' .
1911 "package $package;"; # this won't let them modify, alas
1912 } ## end elsif ($package eq 'DB::fake')
1916 If the program hasn't finished executing, we scan forward to the
1917 next executable line, print that out, build the prompt from the file and line
1918 number information, and print that.
1923 # Still somewhere in the midst of execution. Set up the
1925 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
1926 # Perl 5 ones (sorry, we don't print Klingon
1929 $prefix = $sub =~ /::/ ? "" : "${'package'}::";
1930 $prefix .= "$sub($filename:";
1931 $after = ($dbline[$line] =~ /\n$/ ? '' : "\n");
1933 # Break up the prompt if it's really long.
1934 if (length($prefix) > 30) {
1935 $position = "$prefix$line):\n$line:\t$dbline[$line]$after";
1941 $position = "$prefix$line$infix$dbline[$line]$after";
1944 # Print current line info, indenting if necessary.
1946 print_lineinfo(' ' x $stack_depth, "$line:\t$dbline[$line]$after");
1949 print_lineinfo($position);
1953 # Scan forward, stopping at either the end or the next
1955 for ($i = $line + 1 ; $i <= $max && $dbline[$i] == 0; ++$i)
1958 # Drop out on null statements, block closers, and comments.
1959 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/;
1961 # Drop out if the user interrupted us.
1964 # Append a newline if the line doesn't have one. Can happen
1965 # in eval'ed text, for instance.
1966 $after = ($dbline[$i] =~ /\n$/ ? '' : "\n");
1968 # Next executable line.
1969 $incr_pos = "$prefix$i$infix$dbline[$i]$after";
1970 $position .= $incr_pos;
1972 # Print it indented if tracing is on.
1973 print_lineinfo(' ' x $stack_depth,
1974 "$i:\t$dbline[$i]$after");
1977 print_lineinfo($incr_pos);
1979 } ## end for ($i = $line + 1 ; $i...
1980 } ## end else [ if ($slave_editor)
1981 } ## end if ($single || ($trace...
1985 If there's an action to be executed for the line we stopped at, execute it.
1986 If there are any preprompt actions, execute those as well.
1990 # If there's an action, do it now.
1991 $evalarg = $action, &eval if $action;
1993 # Are we nested another level (e.g., did we evaluate a function
1994 # that had a breakpoint in it at the debugger prompt)?
1995 if ($single || $was_signal) {
1996 # Yes, go down a level.
1997 local $level = $level + 1;
1999 # Do any pre-prompt actions.
2000 foreach $evalarg (@$pre) {
2004 # Complain about too much recursion if we passed the limit.
2005 print $OUT $stack_depth . " levels deep in subroutine calls!\n"
2008 # The line we're currently on. Set $incr to -1 to stay here
2009 # until we get a command that tells us to advance.
2011 $incr = -1; # for backward motion.
2013 # Tack preprompt debugger actions ahead of any actual input.
2014 @typeahead = (@$pretype, @typeahead);
2016 =head2 WHERE ARE WE?
2018 XXX Relocate this section?
2020 The debugger normally shows the line corresponding to the current line of
2021 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2022 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2024 C<$incr> controls by how many lines the "current" line should move forward
2025 after a command is executed. If set to -1, this indicates that the "current"
2026 line shouldn't change.
2028 C<$start> is the "current" line. It is used for things like knowing where to
2029 move forwards or backwards from when doing an C<L> or C<-> command.
2031 C<$max> tells the debugger where the last line of the current file is. It's
2032 used to terminate loops most often.
2034 =head2 THE COMMAND LOOP
2036 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2041 =item * The outer part of the loop, starting at the C<CMD> label. This loop
2042 reads a command and then executes it.
2044 =item * The inner part of the loop, starting at the C<PIPE> label. This part
2045 is wholly contained inside the C<CMD> block and only executes a command.
2046 Used to handle commands running inside a pager.
2050 So why have two labels to restart the loop? Because sometimes, it's easier to
2051 have a command I<generate> another command and then re-execute the loop to do
2052 the new command. This is faster, but perhaps a bit more convoluted.
2056 # The big command dispatch loop. It keeps running until the
2057 # user yields up control again.
2059 # If we have a terminal for input, and we get something back
2060 # from readline(), keep on processing.
2063 # We have a terminal, or can get one ...
2064 ($term || &setterm),
2065 # ... and it belogs to this PID or we get one for this PID ...
2066 ($term_pid == $$ or resetterm(1)),
2068 # ... and we got a line of command input ...
2070 "$pidprompt DB" . ('<' x $level) . ($#hist+1) .
2071 ('>' x $level) . " "
2076 # ... try to execute the input as debugger commands.
2078 # Don't stop running.
2081 # No signal is active.
2084 # Handle continued commands (ending with \):
2085 $cmd =~ s/\\$/\n/ && do {
2086 $cmd .= &readline(" cont: ");
2090 =head4 The null command
2092 A newline entered by itself means "re-execute the last command". We grab the
2093 command out of C<$laststep> (where it was recorded previously), and copy it
2094 back into C<$cmd> to be executed below. If there wasn't any previous command,
2095 we'll do nothing below (no command will match). If there was, we also save it
2096 in the command history and fall through to allow the command parsing to pick
2101 # Empty input means repeat the last command.
2102 $cmd =~ /^$/ && ($cmd = $laststep);
2103 chomp($cmd); # get rid of the annoying extra newline
2104 push (@hist, $cmd) if length($cmd) > 1;
2105 push (@truehist, $cmd);
2107 # This is a restart point for commands that didn't arrive
2108 # via direct user input. It allows us to 'redo PIPE' to
2109 # re-execute command processing without reading a new command.
2111 $cmd =~ s/^\s+//s; # trim annoying leading whitespace
2112 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace
2113 ($i) = split (/\s+/, $cmd);
2115 =head3 COMMAND ALIASES
2117 The debugger can create aliases for commands (these are stored in the
2118 C<%alias> hash). Before a command is executed, the command loop looks it up
2119 in the alias hash and substitutes the contents of the alias for the command,
2120 completely replacing it.
2124 # See if there's an alias for the command, and set it up if so.
2126 # Squelch signal handling; we want to keep control here
2127 # if something goes loco during the alias eval.
2128 local $SIG{__DIE__};
2129 local $SIG{__WARN__};
2131 # This is a command, so we eval it in the DEBUGGER's
2132 # scope! Otherwise, we can't see the special debugger
2133 # variables, or get to the debugger's subs. (Well, we
2134 # _could_, but why make it even more complicated?)
2135 eval "\$cmd =~ $alias{$i}";
2138 print $OUT "Couldn't evaluate `$i' alias: $@";
2141 } ## end if ($alias{$i})
2143 =head3 MAIN-LINE COMMANDS
2145 All of these commands work up to and after the program being debugged has
2150 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2151 try to execute further, cleaning any restart-related stuff out of the
2152 environment, and executing with the last value of C<$?>.
2156 $cmd =~ /^q$/ && do {
2164 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2168 $cmd =~ /^t$/ && do {
2171 print $OUT "Trace = " . (($trace & 1) ? "on" : "off" ) .
2176 =head4 C<S> - list subroutines matching/not matching a pattern
2178 Walks through C<%sub>, checking to see whether or not to print the name.
2182 $cmd =~ /^S(\s+(!)?(.+))?$/ && do {
2184 $Srev = defined $2; # Reverse scan?
2185 $Spatt = $3; # The pattern (if any) to use.
2186 $Snocheck = !defined $1; # No args - print all subs.
2188 # Need to make these sane here.
2192 # Search through the debugger's magical hash of subs.
2193 # If $nocheck is true, just print the sub name.
2194 # Otherwise, check it against the pattern. We then use
2195 # the XOR trick to reverse the condition as required.
2196 foreach $subname (sort(keys %sub)) {
2197 if ($Snocheck or $Srev^($subname =~ /$Spatt/)) {
2198 print $OUT $subname,"\n";
2204 =head4 C<X> - list variables in current package
2206 Since the C<V> command actually processes this, just change this to the
2207 appropriate C<V> command and fall through.
2211 $cmd =~ s/^X\b/V $package/;
2213 =head4 C<V> - list variables
2215 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2219 # Bare V commands get the currently-being-debugged package
2221 $cmd =~ /^V$/ && do {
2222 $cmd = "V $package";
2225 # V - show variables in package.
2226 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
2227 # Save the currently selected filehandle and
2228 # force output to debugger's filehandle (dumpvar
2229 # just does "print" for output).
2230 local ($savout) = select($OUT);
2232 # Grab package name and variables to dump.
2234 @vars = split (' ', $2);
2236 # If main::dumpvar isn't here, get it.
2237 do 'dumpvar.pl' unless defined &main::dumpvar;
2238 if (defined &main::dumpvar) {
2239 # We got it. Turn off subroutine entry/exit messages
2240 # for the moment, along with return values.
2244 # must detect sigpipe failures - not catching
2245 # then will cause the debugger to die.
2249 defined $option{dumpDepth}
2250 ? $option{dumpDepth}
2251 : -1, # assume -1 unless specified
2256 # The die doesn't need to include the $@, because
2257 # it will automatically get propagated for us.
2259 die unless $@ =~ /dumpvar print failed/;
2261 } ## end if (defined &main::dumpvar)
2263 # Couldn't load dumpvar.
2264 print $OUT "dumpvar.pl not available.\n";
2266 # Restore the output filehandle, and go round again.
2271 =head4 C<x> - evaluate and print an expression
2273 Hands the expression off to C<DB::eval>, setting it up to print the value
2274 via C<dumpvar.pl> instead of just printing it directly.
2278 $cmd =~ s/^x\b/ / && do { # Remainder gets done by DB::eval()
2279 $onetimeDump = 'dump'; # main::dumpvar shows the output
2281 # handle special "x 3 blah" syntax XXX propagate
2282 # doc back to special variables.
2283 if ($cmd =~ s/^\s*(\d+)(?=\s)/ /) {
2284 $onetimedumpDepth = $1;
2288 =head4 C<m> - print methods
2290 Just uses C<DB::methods> to determine what methods are available.
2294 $cmd =~ s/^m\s+([\w:]+)\s*$/ / && do {
2299 # m expr - set up DB::eval to do the work
2300 $cmd =~ s/^m\b/ / && do { # Rest gets done by DB::eval()
2301 $onetimeDump = 'methods'; # method output gets used there
2304 =head4 C<f> - switch files
2308 $cmd =~ /^f\b\s*(.*)/ && do {
2312 # help for no arguments (old-style was return from sub).
2314 print $OUT "The old f command is now the r command.\n"; # hint
2315 print $OUT "The new f command switches filenames.\n";
2317 } ## end if (!$file)
2319 # if not in magic file list, try a close match.
2320 if (!defined $main::{'_<' . $file}) {
2321 if (($try) = grep(m#^_<.*$file#, keys %main::)) {
2323 $try = substr($try,2);
2325 "Choosing $try matching `$file':\n";
2328 } ## end if (($try) = grep(m#^_<.*$file#...
2329 } ## end if (!defined $main::{ ...
2331 # If not successfully switched now, we failed.
2332 if (!defined $main::{'_<' . $file}) {
2333 print $OUT "No file matching `$file' is loaded.\n";
2337 # We switched, so switch the debugger internals around.
2338 elsif ($file ne $filename) {
2339 *dbline = $main::{ '_<' . $file };
2344 } ## end elsif ($file ne $filename)
2346 # We didn't switch; say we didn't.
2348 print $OUT "Already in $file.\n";
2353 =head4 C<.> - return to last-executed line.
2355 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2356 and then we look up the line in the magical C<%dbline> hash.
2361 $cmd =~ /^\.$/ && do {
2362 $incr = -1; # for backward motion.
2364 # Reset everything to the old location.
2366 $filename = $filename_ini;
2367 *dbline = $main::{'_<' . $filename};
2371 print_lineinfo($position);
2375 =head4 C<-> - back one window
2377 We change C<$start> to be one window back; if we go back past the first line,
2378 we set it to be the first line. We ser C<$incr> to put us back at the
2379 currently-executing line, and then put a C<l $start +> (list one window from
2380 C<$start>) in C<$cmd> to be executed later.
2384 # - - back a window.
2385 $cmd =~ /^-$/ && do {
2386 # back up by a window; go to 1 if back too far.
2387 $start -= $incr + $window + 1;
2388 $start = 1 if $start <= 0;
2389 $incr = $window - 1;
2391 # Generate and execute a "l +" command (handled below).
2392 $cmd = 'l ' . ($start) . '+';
2395 =head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, {, {{>
2397 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2398 problems, most notably that the default case of several commands destroying
2399 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2400 retain the old commands for those who were used to using them or who preferred
2401 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2402 deal with them instead of processing them in-line.
2406 # All of these commands were remapped in perl 5.8.0;
2407 # we send them off to the secondary dispatcher (see below).
2408 $cmd =~ /^([aAbBhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so && do {
2409 &cmd_wrapper($1, $2, $line);
2413 =head4 C<y> - List lexicals in higher scope
2415 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2416 above the current one and then displays then using C<dumpvar.pl>.
2420 $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/ && do {
2422 # See if we've got the necessary support.
2423 eval { require PadWalker; PadWalker->VERSION(0.08) }
2426 ? "PadWalker module not found - please install\n"
2431 # Load up dumpvar if we don't have it. If we can, that is.
2432 do 'dumpvar.pl' unless defined &main::dumpvar;
2433 defined &main::dumpvar
2434 or print $OUT "dumpvar.pl not available.\n"
2437 # Got all the modules we need. Find them and print them.
2438 my @vars = split (' ', $2 || '');
2441 my $h = eval { PadWalker::peek_my(($1 || 0) + 1) };
2443 # Oops. Can't find it.
2444 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2446 # Show the desired vars with dumplex().
2447 my $savout = select($OUT);
2449 # Have dumplex dump the lexicals.
2453 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
2455 ) for sort keys %$h;
2460 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2462 All of the commands below this point don't work after the program being
2463 debugged has ended. All of them check to see if the program has ended; this
2464 allows the commands to be relocated without worrying about a 'line of
2465 demarcation' above which commands can be entered anytime, and below which
2468 =head4 C<n> - single step, but don't trace down into subs
2470 Done by setting C<$single> to 2, which forces subs to execute straight through
2471 when entered (see X<DB::sub>). We also save the C<n> command in C<$laststep>,
2472 so a null command knows what to re-execute.
2477 $cmd =~ /^n$/ && do {
2478 end_report(), next CMD if $finished and $level <= 1;
2479 # Single step, but don't enter subs.
2481 # Save for empty command (repeat last).
2486 =head4 C<s> - single-step, entering subs
2488 Sets C<$single> to 1, which causes X<DB::sub> to continue tracing inside
2489 subs. Also saves C<s> as C<$lastcmd>.
2494 $cmd =~ /^s$/ && do {
2495 # Get out and restart the command loop if program
2497 end_report(), next CMD if $finished and $level <= 1;
2498 # Single step should enter subs.
2500 # Save for empty command (repeat last).
2505 =head4 C<c> - run continuously, setting an optional breakpoint
2507 Most of the code for this command is taken up with locating the optional
2508 breakpoint, which is either a subroutine name or a line number. We set
2509 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2510 in this and all call levels above this one.
2514 # c - start continuous execution.
2515 $cmd =~ /^c\b\s*([\w:]*)\s*$/ && do {
2516 # Hey, show's over. The debugged program finished
2517 # executing already.
2518 end_report(), next CMD if $finished and $level <= 1;
2520 # Capture the place to put a one-time break.
2523 # Probably not needed, since we finish an interactive
2524 # sub-session anyway...
2525 # local $filename = $filename;
2526 # local *dbline = *dbline; # XXX Would this work?!
2528 # The above question wonders if localizing the alias
2529 # to the magic array works or not. Since it's commented
2530 # out, we'll just leave that to speculation for now.
2532 # If the "subname" isn't all digits, we'll assume it
2533 # is a subroutine name, and try to find it.
2534 if ($subname =~ /\D/) { # subroutine name
2535 # Qualify it to the current package unless it's
2536 # already qualified.
2537 $subname = $package . "::" . $subname
2538 unless $subname =~ /::/;
2539 # find_sub will return "file:line_number" corresponding
2540 # to where the subroutine is defined; we call find_sub,
2541 # break up the return value, and assign it in one
2543 ($file,$i) = (find_sub($subname) =~ /^(.*):(.*)$/);
2545 # Force the line number to be numeric.
2548 # If we got a line number, we found the sub.
2550 # Switch all the debugger's internals around so
2551 # we're actually working with that file.
2553 *dbline = $main::{'_<' . $filename};
2554 # Mark that there's a breakpoint in this file.
2555 $had_breakpoints{$filename} |= 1;
2556 # Scan forward to the first executable line
2557 # after the 'sub whatever' line.
2559 ++$i while $dbline[$i] == 0 && $i < $max;
2562 # We didn't find a sub by that name.
2564 print $OUT "Subroutine $subname not found.\n";
2567 } ## end if ($subname =~ /\D/)
2569 # At this point, either the subname was all digits (an
2570 # absolute line-break request) or we've scanned through
2571 # the code following the definition of the sub, looking
2572 # for an executable, which we may or may not have found.
2574 # If $i (which we set $subname from) is non-zero, we
2575 # got a request to break at some line somewhere. On
2576 # one hand, if there wasn't any real subroutine name
2577 # involved, this will be a request to break in the current
2578 # file at the specified line, so we have to check to make
2579 # sure that the line specified really is breakable.
2581 # On the other hand, if there was a subname supplied, the
2582 # preceeding block has moved us to the proper file and
2583 # location within that file, and then scanned forward
2584 # looking for the next executable line. We have to make
2585 # sure that one was found.
2587 # On the gripping hand, we can't do anything unless the
2588 # current value of $i points to a valid breakable line.
2592 if ($dbline[$i] == 0) {
2593 print $OUT "Line $i not breakable.\n";
2596 # Yes. Set up the one-time-break sigil.
2598 s/($|\0)/;9$1/; # add one-time-only b.p.
2601 # Turn off stack tracing from here up.
2602 for ($i=0; $i <= $stack_depth; ) {
2608 =head4 C<r> - return from a subroutine
2610 For C<r> to work properly, the debugger has to stop execution again
2611 immediately after the return is executed. This is done by forcing
2612 single-stepping to be on in the call level above the current one. If
2613 we are printing return values when a C<r> is executed, set C<$doret>
2614 appropriately, and force us out of the command loop.
2618 # r - return from the current subroutine.
2619 $cmd =~ /^r$/ && do {
2620 # Can't do anythign if the program's over.
2621 end_report(), next CMD if $finished and $level <= 1;
2622 # Turn on stack trace.
2623 $stack[$stack_depth] |= 1;
2624 # Print return value unless the stack is empty.
2625 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2629 =head4 C<R> - restart
2631 Restarting the debugger is a complex operation that occurs in several phases.
2632 First, we try to reconstruct the command line that was used to invoke Perl
2637 # R - restart execution.
2638 $cmd =~ /^R$/ && do {
2639 # I may not be able to resurrect you, but here goes ...
2641 "Warning: some settings and command-line options may be lost!\n";
2642 my (@script, @flags, $cl);
2644 # If warn was on before, turn it on again.
2645 push @flags, '-w' if $ini_warn;
2646 if ($ini_assertion and @{^ASSERTING}) {
2647 push @flags, (map { /\:\^\(\?\:(.*)\)\$\)/ ?
2648 "-A$1" : "-A$_" } @{^ASSERTING});
2650 # Rebuild the -I flags that were on the initial
2653 push @flags, '-I', $_;
2656 # Turn on taint if it was on before.
2657 push @flags, '-T' if ${^TAINT};
2659 # Arrange for setting the old INC:
2660 # Save the current @init_INC in the environment.
2661 set_list("PERLDB_INC", @ini_INC);
2663 # If this was a perl one-liner, go to the "file"
2664 # corresponding to the one-liner read all the lines
2665 # out of it (except for the first one, which is going
2666 # to be added back on again when 'perl -d' runs: that's
2667 # the 'require perl5db.pl;' line), and add them back on
2668 # to the command line to be executed.
2670 for (1..$#{'::_<-e'}) { # The first line is PERL5DB
2671 chomp ($cl = ${'::_<-e'}[$_]);
2672 push @script, '-e', $cl;
2674 } ## end if ($0 eq '-e')
2676 # Otherwise we just reuse the original name we had
2684 After the command line has been reconstructed, the next step is to save
2685 the debugger's status in environment variables. The C<DB::set_list> routine
2686 is used to save aggregate variables (both hashes and arrays); scalars are
2687 just popped into environment variables directly.
2691 # If the terminal supported history, grab it and
2692 # save that in the environment.
2693 set_list("PERLDB_HIST",
2694 $term->Features->{getHistory}
2697 # Find all the files that were visited during this
2698 # session (i.e., the debugger had magic hashes
2699 # corresponding to them) and stick them in the environment.
2700 my @had_breakpoints = keys %had_breakpoints;
2701 set_list("PERLDB_VISITED", @had_breakpoints);
2703 # Save the debugger options we chose.
2704 set_list("PERLDB_OPT", options2remember());
2706 # Save the break-on-loads.
2707 set_list("PERLDB_ON_LOAD", %break_on_load);
2711 The most complex part of this is the saving of all of the breakpoints. They
2712 can live in an awful lot of places, and we have to go through all of them,
2713 find the breakpoints, and then save them in the appropriate environment
2714 variable via C<DB::set_list>.
2718 # Go through all the breakpoints and make sure they're
2721 for (0 .. $#had_breakpoints) {
2722 # We were in this file.
2723 my $file = $had_breakpoints[$_];
2725 # Grab that file's magic line hash.
2726 *dbline = $main::{'_<' . $file};
2728 # Skip out if it doesn't exist, or if the breakpoint
2729 # is in a postponed file (we'll do postponed ones
2731 next unless %dbline or $postponed_file{$file};
2733 # In an eval. This is a little harder, so we'll
2734 # do more processing on that below.
2735 (push @hard, $file), next
2736 if $file =~ /^\(\w*eval/;
2737 # XXX I have no idea what this is doing. Yet.
2739 @add = %{$postponed_file{$file}}
2740 if $postponed_file{$file};
2742 # Save the list of all the breakpoints for this file.
2743 set_list("PERLDB_FILE_$_", %dbline, @add);
2744 } ## end for (0 .. $#had_breakpoints)
2746 # The breakpoint was inside an eval. This is a little
2747 # more difficult. XXX and I don't understand it.
2748 for (@hard) { # Yes, really-really...
2749 # Get over to the eval in question.
2750 *dbline = $main::{'_<' . $_};
2751 my ($quoted, $sub, %subs, $line) = quotemeta $_;
2752 for $sub (keys %sub) {
2753 next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/;
2754 $subs{$sub} = [$1, $2];
2758 "No subroutines in $_, ignoring breakpoints.\n";
2761 LINES: for $line (keys %dbline) {
2763 # One breakpoint per sub only:
2764 my ($offset, $sub, $found);
2765 SUBS: for $sub (keys %subs) {
2767 $subs{$sub}->[1] >= $line # Not after the subroutine
2768 and (not defined $offset # Not caught
2769 or $offset < 0 )) { # or badly caught
2771 $offset = $line - $subs{$sub}->[0];
2772 $offset = "+$offset", last SUBS if $offset >= 0;
2775 if (defined $offset) {
2776 $postponed{$found} =
2777 "break $offset if $dbline{$line}";
2779 print $OUT "Breakpoint in $_:$line ignored: after all the subroutines.\n";
2782 } ## end for $line (keys %dbline)
2783 } ## end for (@hard)
2784 # Save the other things that don't need to be
2786 set_list("PERLDB_POSTPONE", %postponed);
2787 set_list("PERLDB_PRETYPE", @$pretype);
2788 set_list("PERLDB_PRE", @$pre);
2789 set_list("PERLDB_POST", @$post);
2790 set_list("PERLDB_TYPEAHEAD", @typeahead);
2792 # We are oficially restarting.
2793 $ENV{PERLDB_RESTART} = 1;
2795 # We are junking all child debuggers.
2796 delete $ENV{PERLDB_PIDS}; # Restore ini state
2798 # Set this back to the initial pid.
2799 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
2803 After all the debugger status has been saved, we take the command we built
2804 up and then C<exec()> it. The debugger will spot the C<PERLDB_RESTART>
2805 environment variable and realize it needs to reload its state from the
2810 # And run Perl again. Add the "-d" flag, all the
2811 # flags we built up, the script (whether a one-liner
2812 # or a file), add on the -emacs flag for a slave editor,
2813 # and then the old arguments. We use exec() to keep the
2814 # PID stable (and that way $ini_pids is still valid).
2815 exec($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS) ||
2816 print $OUT "exec failed: $!\n";
2820 =head4 C<T> - stack trace
2822 Just calls C<DB::print_trace>.
2826 $cmd =~ /^T$/ && do {
2827 print_trace($OUT, 1); # skip DB
2831 =head4 C<w> - List window around current line.
2833 Just calls C<DB::cmd_w>.
2837 $cmd =~ /^w\b\s*(.*)/s && do { &cmd_w('w', $1); next CMD; };
2839 =head4 C<W> - watch-expression processing.
2841 Just calls C<DB::cmd_W>.
2845 $cmd =~ /^W\b\s*(.*)/s && do { &cmd_W('W', $1); next CMD; };
2847 =head4 C</> - search forward for a string in the source
2849 We take the argument and treat it as a pattern. If it turns out to be a
2850 bad one, we return the error we got from trying to C<eval> it and exit.
2851 If not, we create some code to do the search and C<eval> it so it can't
2856 $cmd =~ /^\/(.*)$/ && do {
2858 # The pattern as a string.
2861 # Remove the final slash.
2862 $inpat =~ s:([^\\])/$:$1:;
2864 # If the pattern isn't null ...
2867 # Turn of warn and die procesing for a bit.
2868 local $SIG{__DIE__};
2869 local $SIG{__WARN__};
2871 # Create the pattern.
2872 eval '$inpat =~ m'."\a$inpat\a";
2874 # Oops. Bad pattern. No biscuit.
2875 # Print the eval error and go back for more
2881 } ## end if ($inpat ne "")
2883 # Set up to stop on wrap-around.
2886 # Don't move off the current line.
2889 # Done in eval so nothing breaks if the pattern
2890 # does something weird.
2893 # Move ahead one line.
2896 # Wrap if we pass the last line.
2897 $start = 1 if ($start > $max);
2899 # Stop if we have gotten back to this line again,
2900 last if ($start == $end);
2902 # A hit! (Note, though, that we are doing
2903 # case-insensitive matching. Maybe a qr//
2904 # expression would be better, so the user could
2905 # do case-sensitive matching if desired.
2906 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2907 if ($slave_editor) {
2908 # Handle proper escaping in the slave.
2909 print $OUT "\032\032$filename:$start:0\n";
2912 # Just print the line normally.
2913 print $OUT "$start:\t", $dbline[$start], "\n";
2915 # And quit since we found something.
2919 # If we wrapped, there never was a match.
2920 print $OUT "/$pat/: not found\n" if ($start == $end);
2924 =head4 C<?> - search backward for a string in the source
2926 Same as for C</>, except the loop runs backwards.
2930 # ? - backward pattern search.
2931 $cmd =~ /^\?(.*)$/ && do {
2933 # Get the pattern, remove trailing question mark.
2935 $inpat =~ s:([^\\])\?$:$1:;
2937 # If we've got one ...
2940 # Turn off die & warn handlers.
2941 local $SIG{__DIE__};
2942 local $SIG{__WARN__};
2943 eval '$inpat =~ m'."\a$inpat\a";
2945 # Ouch. Not good. Print the error.
2950 } ## end if ($inpat ne "")
2951 # Where we are now is where to stop after wraparound.
2954 # Don't move away from this line.
2957 # Search inside the eval to prevent pattern badness
2965 # Wrap if we pass the first line.
2966 $start = $max if ($start <= 0);
2968 # Quit if we get back where we started,
2969 last if ($start == $end);
2972 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2973 if ($slave_editor) {
2974 # Yep, follow slave editor requirements.
2975 print $OUT "\032\032$filename:$start:0\n";
2978 # Yep, just print normally.
2979 print $OUT "$start:\t", $dbline[$start], "\n";
2986 print $OUT "?$pat?: not found\n" if ($start == $end);
2990 =head4 C<$rc> - Recall command
2992 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2993 that the terminal supports history). It find the the command required, puts it
2994 into C<$cmd>, and redoes the loop to execute it.
2998 # $rc - recall command.
2999 $cmd =~ /^$rc+\s*(-)?(\d+)?$/ && do {
3001 # No arguments, take one thing off history.
3002 pop (@hist) if length($cmd) > 1;
3004 # Relative (- found)?
3005 # Y - index back from most recent (by 1 if bare minus)
3006 # N - go to that particular command slot or the last
3007 # thing if nothing following.
3008 $i = $1 ? ($#hist-($2||1)) : ($2||$#hist);
3010 # Pick out the command desired.
3013 # Print the command to be executed and restart the loop
3014 # with that command in the buffer.
3015 print $OUT $cmd, "\n";
3019 =head4 C<$sh$sh> - C<system()> command
3021 Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
3022 C<STDOUT> from getting messed up.
3026 # $sh$sh - run a shell command (if it's all ASCII).
3027 # Can't run shell commands with Unicode in the debugger, hmm.
3028 $cmd =~ /^$sh$sh\s*([\x00-\xff]*)/ && do {
3034 =head4 C<$rc I<pattern> $rc> - Search command history
3036 Another command to manipulate C<@hist>: this one searches it with a pattern.
3037 If a command is found, it is placed in C<$cmd> and executed via <redo>.
3041 # $rc pattern $rc - find a command in the history.
3042 $cmd =~ /^$rc([^$rc].*)$/ && do {
3043 # Create the pattern to use.
3046 # Toss off last entry if length is >1 (and it always is).
3047 pop (@hist) if length($cmd) > 1;
3049 # Look backward through the history.
3050 for ($i = $#hist; $i; --$i) {
3051 # Stop if we find it.
3052 last if $hist[$i] =~ /$pat/;
3057 print $OUT "No such command!\n\n";
3061 # Found it. Put it in the buffer, print it, and process it.
3063 print $OUT $cmd, "\n";
3067 =head4 C<$sh> - Invoke a shell
3069 Uses C<DB::system> to invoke a shell.
3073 # $sh - start a shell.
3074 $cmd =~ /^$sh$/ && do {
3075 # Run the user's shell. If none defined, run Bourne.
3076 # We resume execution when the shell terminates.
3077 &system($ENV{SHELL}||"/bin/sh");
3081 =head4 C<$sh I<command>> - Force execution of a command in a shell
3083 Like the above, but the command is passed to the shell. Again, we use
3084 C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
3088 # $sh command - start a shell and run a command in it.
3089 $cmd =~ /^$sh\s*([\x00-\xff]*)/ && do {
3090 # XXX: using csh or tcsh destroys sigint retvals!
3091 #&system($1); # use this instead
3093 # use the user's shell, or Bourne if none defined.
3094 &system($ENV{SHELL}||"/bin/sh","-c",$1);
3098 =head4 C<H> - display commands in history
3100 Prints the contents of C<@hist> (if any).
3104 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
3105 # Anything other than negative numbers is ignored by
3106 # the (incorrect) pattern, so this test does nothing.
3107 $end = $2 ? ($#hist-$2) : 0;
3109 # Set to the minimum if less than zero.
3110 $hist = 0 if $hist < 0;
3112 # Start at the end of the array.
3113 # Stay in while we're still above the ending value.
3114 # Tick back by one each time around the loop.
3115 for ($i=$#hist; $i>$end; $i--) {
3117 # Print the command unless it has no arguments.
3118 print $OUT "$i: ",$hist[$i],"\n"
3119 unless $hist[$i] =~ /^.?$/;
3124 =head4 C<man, doc, perldoc> - look up documentation
3126 Just calls C<runman()> to print the appropriate document.
3130 # man, perldoc, doc - show manual pages.
3131 $cmd =~ /^(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?$/ && do {
3138 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3139 the bottom of the loop.
3143 # p - print (no args): print $_.
3144 $cmd =~ s/^p$/print {\$DB::OUT} \$_/;
3146 # p - print the given expression.
3147 $cmd =~ s/^p\b/print {\$DB::OUT} /;
3149 =head4 C<=> - define command alias
3151 Manipulates C<%alias> to add or list command aliases.
3155 # = - set up a command alias.
3156 $cmd =~ s/^=\s*// && do {
3158 if (length $cmd == 0) {
3159 # No args, get current aliases.
3160 @keys = sort keys %alias;
3161 } elsif (my($k,$v) = ($cmd =~ /^(\S+)\s+(\S.*)/)) {
3162 # Creating a new alias. $k is alias name, $v is
3165 # can't use $_ or kill //g state
3166 for my $x ($k, $v) {
3167 # Escape "alarm" characters.
3171 # Substitute key for value, using alarm chars
3172 # as separators (which is why we escaped them in
3174 $alias{$k} = "s\a$k\a$v\a";
3176 # Turn off standard warn and die behavior.
3177 local $SIG{__DIE__};
3178 local $SIG{__WARN__};
3181 unless (eval "sub { s\a$k\a$v\a }; 1") {
3182 # Nope. Bad alias. Say so and get out.
3183 print $OUT "Can't alias $k to $v: $@\n";
3187 # We'll only list the new one.
3189 } ## end elsif (my ($k, $v) = ($cmd...
3191 # The argument is the alias to list.
3198 # Messy metaquoting: Trim the substiution code off.
3199 # We use control-G as the delimiter because it's not
3200 # likely to appear in the alias.
3201 if ((my $v = $alias{$k}) =~ s
\as\a$k\a(.*)\a$
\a1
\a) {
3203 print $OUT "$k\t= $1\n";
3205 elsif (defined $alias{$k}) {
3206 # Couldn't trim it off; just print the alias code.
3207 print $OUT "$k\t$alias{$k}\n";
3211 print "No alias for $k\n";
3213 } ## end for my $k (@keys)
3217 =head4 C<source> - read commands from a file.
3219 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3224 # source - read commands from a file (or pipe!) and execute.
3225 $cmd =~ /^source\s+(.*\S)/ && do {
3226 if (open my $fh, $1) {
3227 # Opened OK; stick it in the list of file handles.
3232 &warn("Can't execute `$1': $!\n");
3237 =head4 C<save> - send current history to a file
3239 Takes the complete history, (not the shrunken version you see with C<H>),
3240 and saves it to the given filename, so it can be replayed using C<source>.
3242 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3246 # save source - write commands to a file for later use
3247 $cmd =~ /^save\s*(.*)$/ && do {
3248 my $file = $1 || '.perl5dbrc'; # default?
3249 if (open my $fh, "> $file") {
3250 # chomp to remove extraneous newlines from source'd files
3251 chomp(my @truelist = map { m/^\s*(save|source)/ ? "#$_": $_ } @truehist);
3252 print $fh join("\n", @truelist);
3253 print "commands saved in $file\n";
3255 &warn("Can't save debugger commands in '$1': $!\n");
3260 =head4 C<|, ||> - pipe output through the pager.
3262 FOR C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3263 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3264 pipe to the pager (restoring the output filehandles if this fails). If this
3265 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3266 set C<$signal>, sending us back into the debugger.
3268 We then trim off the pipe symbols and C<redo> the command loop at the
3269 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3274 # || - run command in the pager, with output to DB::OUT.
3275 $cmd =~ /^\|\|?\s*[^|]/ && do {
3276 if ($pager =~ /^\|/) {
3277 # Default pager is into a pipe. Redirect I/O.
3278 open(SAVEOUT,">&STDOUT") ||
3279 &warn("Can't save STDOUT");
3280 open(STDOUT,">&OUT") ||
3281 &warn("Can't redirect STDOUT");
3282 } ## end if ($pager =~ /^\|/)
3284 # Not into a pipe. STDOUT is safe.
3285 open(SAVEOUT,">&OUT") || &warn("Can't save DB::OUT");
3288 # Fix up environment to record we have less if so.
3291 unless ($piped=open(OUT,$pager)) {
3292 # Couldn't open pipe to pager.
3293 &warn("Can't pipe output to `$pager'");
3294 if ($pager =~ /^\|/) {
3295 # Redirect I/O back again.
3296 open(OUT,">&STDOUT") # XXX: lost message
3297 || &warn("Can't restore DB::OUT");
3298 open(STDOUT,">&SAVEOUT")
3299 || &warn("Can't restore STDOUT");
3301 } ## end if ($pager =~ /^\|/)
3303 # Redirect I/O. STDOUT already safe.
3304 open(OUT,">&STDOUT") # XXX: lost message
3305 || &warn("Can't restore DB::OUT");
3308 } ## end unless ($piped = open(OUT,...
3310 # Set up broken-pipe handler if necessary.
3311 $SIG{PIPE}= \&DB::catch
3312 if $pager =~ /^\|/ &&
3313 ("" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE});
3315 # Save current filehandle, unbuffer out, and put it back.
3316 $selected= select(OUT);
3319 # Don't put it back if pager was a pipe.
3320 select( $selected ), $selected= "" unless $cmd =~ /^\|\|/;
3322 # Trim off the pipe symbols and run the command now.
3323 $cmd =~ s/^\|+\s*//;
3327 =head3 END OF COMMAND PARSING
3329 Anything left in C<$cmd> at this point is a Perl expression that we want to
3330 evaluate. We'll always evaluate in the user's context, and fully qualify
3331 any variables we might want to address in the C<DB> package.
3335 # t - turn trace on.
3336 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3338 # s - single-step. Remember the last command was 's'.
3339 $cmd =~ s/^s\s/\$DB::single = 1;\n/ && do {$laststep = 's'};
3341 # n - single-step, but not into subs. Remember last command
3342 $cmd =~ s/^n\s/\$DB::single = 2;\n/ && do {$laststep = 'n'};
3346 # Make sure the flag that says "the debugger's running" is
3347 # still on, to make sure we get control again.
3348 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3350 # Run *our* eval that executes in the caller's context.
3353 # Turn off the one-time-dump stuff now.
3355 $onetimeDump = undef;
3356 $onetimedumpDepth = undef;
3358 elsif ($term_pid == $$) {
3361 # XXX If this is the master pid, print a newline.
3364 } ## end while (($term || &setterm...
3366 =head3 POST-COMMAND PROCESSING
3368 After each command, we check to see if the command output was piped anywhere.
3369 If so, we go through the necessary code to unhook the pipe and go back to
3370 our standard filehandles for input and output.
3376 # At the end of every command:
3378 # Unhook the pipe mechanism now.
3379 if ($pager =~ /^\|/) {
3380 # No error from the child.
3383 # we cannot warn here: the handle is missing --tchrist
3384 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
3386 # most of the $? crud was coping with broken cshisms
3387 # $? is explicitly set to 0, so this never runs.
3389 print SAVEOUT "Pager `$pager' failed: ";
3391 print SAVEOUT "shell returned -1\n";
3394 print SAVEOUT ( $? & 127 )
3395 ? " (SIG#".($?&127).")"
3396 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3399 print SAVEOUT "status ", ($? >> 8), "\n";
3403 # Reopen filehandle for our output (if we can) and
3404 # restore STDOUT (if we can).
3405 open(OUT,">&STDOUT") || &warn("Can't restore DB::OUT");
3406 open(STDOUT,">&SAVEOUT") ||
3407 &warn("Can't restore STDOUT");
3409 # Turn off pipe exception handler if necessary.
3410 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
3412 # Will stop ignoring SIGPIPE if done like nohup(1)
3413 # does SIGINT but Perl doesn't give us a choice.
3414 } ## end if ($pager =~ /^\|/)
3416 # Non-piped "pager". Just restore STDOUT.
3417 open(OUT,">&SAVEOUT") || &warn("Can't restore DB::OUT");
3420 # Close filehandle pager was using, restore the normal one
3423 select($selected), $selected= "" unless $selected eq "";
3427 } ## end if ($piped)
3430 =head3 COMMAND LOOP TERMINATION
3432 When commands have finished executing, we come here. If the user closed the
3433 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3434 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3435 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3436 The interpreter will then execute the next line and then return control to us
3441 # No more commands? Quit.
3442 $fall_off_end = 1 unless defined $cmd; # Emulate `q' on EOF
3444 # Evaluate post-prompt commands.
3445 foreach $evalarg (@$post) {
3448 } # if ($single || $signal)
3450 # Put the user's globals back where you found them.
3451 ($@, $!, $^E, $,, $/, $\, $^W) = @saved;
3455 # The following code may be executed now:
3460 C<sub> is called whenever a subroutine call happens in the program being
3461 debugged. The variable C<$DB::sub> contains the name of the subroutine
3464 The core function of this subroutine is to actually call the sub in the proper
3465 context, capturing its output. This of course causes C<DB::DB> to get called
3466 again, repeating until the subroutine ends and returns control to C<DB::sub>
3467 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3468 return value, and returns its captured copy of the return value as its own
3469 return value. The value then feeds back into the program being debugged as if
3470 C<DB::sub> hadn't been there at all.
3472 C<sub> does all the work of printing the subroutine entry and exit messages
3473 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3474 and also prints the return value if needed (for the C<r> command and if
3475 the 16 bit is set in C<$frame>).
3477 It also tracks the subroutine call depth by saving the current setting of
3478 C<$single> in the C<@stack> package global; if this exceeds the value in
3479 C<$deep>, C<sub> automatically turns on printing of the current depth by
3480 setting the 4 bit in C<$single>. In any case, it keeps the current setting
3481 of stop/don't stop on entry to subs set as it currently is set.
3483 =head3 C<caller()> support
3485 If C<caller()> is called from the package C<DB>, it provides some
3486 additional data, in the following order:
3492 The package name the sub was in
3494 =item * C<$filename>
3496 The filename it was defined in
3500 The line number it was defined on
3502 =item * C<$subroutine>
3504 The subroutine name; C<'(eval)'> if an C<eval>().
3508 1 if it has arguments, 0 if not
3510 =item * C<$wantarray>
3512 1 if array context, 0 if scalar context
3514 =item * C<$evaltext>
3516 The C<eval>() text, if any (undefined for C<eval BLOCK>)
3518 =item * C<$is_require>
3520 frame was created by a C<use> or C<require> statement
3524 pragma information; subject to change between versions
3528 pragma information: subject to change between versions
3530 =item * C<@DB::args>
3532 arguments with which the subroutine was invoked
3541 # Whether or not the autoloader was running, a scalar to put the
3542 # sub's return value in (if needed), and an array to put the sub's
3543 # return value in (if needed).
3544 my ($al, $ret, @ret) = "";
3546 # If the last ten characters are C'::AUTOLOAD', note we've traced
3547 # into AUTOLOAD for $sub.
3548 if (length($sub) > 10 && substr($sub, -10, 10) eq '::AUTOLOAD') {
3552 # We stack the stack pointer and then increment it to protect us
3553 # from a situation that might unwind a whole bunch of call frames
3554 # at once. Localizing the stack pointer means that it will automatically
3555 # unwind the same amount when multiple stack frames are unwound.
3556 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3559 $#stack = $stack_depth;
3561 # Save current single-step setting.
3562 $stack[-1] = $single;
3564 # Turn off all flags except single-stepping.
3567 # If we've gotten really deeply recursed, turn on the flag that will
3568 # make us stop with the 'deep recursion' message.
3569 $single |= 4 if $stack_depth == $deep;
3571 # If frame messages are on ...
3573 $frame & 4 # Extended frame entry message
3574 ? ( print_lineinfo(' ' x ($stack_depth - 1), "in "),
3576 # Why -1? But it works! :-(
3577 # Because print_trace will call add 1 to it and then call
3578 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3580 print_trace($LINEINFO, -1, 1, 1, "$sub$al")
3582 : print_lineinfo(' ' x ($stack_depth - 1), "entering $sub$al\n")
3583 # standard frame entry message
3587 # Determine the sub's return type,and capture approppriately.
3589 # Called in array context. call sub and capture output.
3590 # DB::DB will recursively get control again if appropriate; we'll come
3591 # back here when the sub is finished.
3599 $signal=1 unless $warnassertions;
3606 # Pop the single-step value back off the stack.
3607 $single |= $stack[$stack_depth--];
3609 # Check for exit trace messages...
3611 $frame & 4 # Extended exit message
3612 ? ( print_lineinfo(' ' x $stack_depth, "out "),
3613 print_trace($LINEINFO, -1, 1, 1, "$sub$al")
3615 : print_lineinfo(' ' x $stack_depth, "exited $sub$al\n")
3616 # Standard exit message
3620 # Print the return info if we need to.
3621 if ($doret eq $stack_depth or $frame & 16) {
3622 # Turn off output record separator.
3624 my $fh = ($doret eq $stack_depth ? $OUT : $LINEINFO);
3626 # Indent if we're printing because of $frame tracing.
3627 print $fh ' ' x $stack_depth if $frame & 16;
3629 # Print the return value.
3630 print $fh "list context return from $sub:\n";
3631 dumpit($fh, \@ret );
3633 # And don't print it again.
3635 } ## end if ($doret eq $stack_depth...
3636 # And we have to return the return value now.
3638 } ## end if (wantarray)
3645 # Save the value if it's wanted at all.
3650 $signal=1 unless $warnassertions;
3652 $ret=undef unless defined wantarray;
3655 if (defined wantarray) {
3656 # Save the value if it's wanted at all.
3660 # Void return, explicitly.
3666 # Pop the single-step value off the stack.
3667 $single |= $stack[$stack_depth--];
3669 # If we're doing exit messages...
3671 $frame & 4 # Extended messsages
3673 print_lineinfo(' ' x $stack_depth, "out "),
3674 print_trace($LINEINFO, -1, 1, 1, "$sub$al")
3676 : print_lineinfo(' ' x $stack_depth, "exited $sub$al\n")
3681 # If we are supposed to show the return value... same as before.
3682 if ($doret eq $stack_depth or $frame & 16 and defined wantarray) {
3684 my $fh = ($doret eq $stack_depth ? $OUT : $LINEINFO);
3685 print $fh (' ' x $stack_depth) if $frame & 16;
3686 print $fh (defined wantarray
3687 ? "scalar context return from $sub: "
3688 : "void context return from $sub\n"
3690 dumpit( $fh, $ret ) if defined wantarray;
3692 } ## end if ($doret eq $stack_depth...
3694 # Return the appropriate scalar value.
3696 } ## end else [ if (wantarray)
3699 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
3701 In Perl 5.8.0, there was a major realignment of the commands and what they did,
3702 Most of the changes were to systematize the command structure and to eliminate
3703 commands that threw away user input without checking.
3705 The following sections describe the code added to make it easy to support
3706 multiple command sets with conflicting command names. This section is a start
3707 at unifying all command processing to make it simpler to develop commands.
3709 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
3710 number, and C<$dbline> (the current line) as arguments.
3712 Support functions in this section which have multiple modes of failure C<die>
3713 on error; the rest simply return a false value.
3715 The user-interface functions (all of the C<cmd_*> functions) just output
3720 The C<%set> hash defines the mapping from command letter to subroutine
3723 C<%set> is a two-level hash, indexed by set name and then by command name.
3724 Note that trying to set the CommandSet to 'foobar' simply results in the
3725 5.8.0 command set being used, since there's no top-level entry for 'foobar'.
3731 ### Functions with multiple modes of failure die on error, the rest
3732 ### returns FALSE on error.
3733 ### User-interface functions cmd_* output error message.
3735 ### Note all cmd_[a-zA-Z]'s require $cmd, $line, $dblineno as first arguments
3740 'A' => 'pre580_null',
3742 'B' => 'pre580_null',
3743 'd' => 'pre580_null',
3746 'M' => 'pre580_null',
3748 'o' => 'pre580_null',
3754 '<' => 'pre590_prepost',
3755 '<<' => 'pre590_prepost',
3756 '>' => 'pre590_prepost',
3757 '>>' => 'pre590_prepost',
3758 '{' => 'pre590_prepost',
3759 '{{' => 'pre590_prepost',
3763 =head2 C<cmd_wrapper()> (API)
3765 C<cmd_wrapper()> allows the debugger to switch command sets
3766 depending on the value of the C<CommandSet> option.
3768 It tries to look up the command in the X<C<%set>> package-level I<lexical>
3769 (which means external entities can't fiddle with it) and create the name of
3770 the sub to call based on the value found in the hash (if it's there). I<All>
3771 of the commands to be handled in a set have to be added to C<%set>; if they
3772 aren't found, the 5.8.0 equivalent is called (if there is one).
3774 This code uses symbolic references.
3781 my $dblineno = shift;
3783 # Assemble the command subroutine's name by looking up the
3784 # command set and command name in %set. If we can't find it,
3785 # default to the older version of the command.
3787 .( $set{$CommandSet}{$cmd}
3788 || ($cmd =~ /^[<>{]+/o ? 'prepost' : $cmd));
3791 # Call the command subroutine, call it by name.
3792 return &$call($cmd, $line, $dblineno);
3795 =head3 C<cmd_a> (command)
3797 The C<a> command handles pre-execution actions. These are associated with a
3798 particular line, so they're stored in C<%dbline>. We default to the current
3799 line if none is specified.
3805 my $line = shift || ''; # [.|line] expr
3808 # If it's dot (here), or not all digits, use the current line.
3809 $line =~ s/^(\.|(?:[^\d]))/$dbline/;
3811 # Should be a line number followed by an expression.
3812 if ($line =~ /^\s*(\d*)\s*(\S.+)/) {
3813 my ($lineno, $expr) = ($1, $2);
3815 # If we have an expression ...
3817 # ... but the line isn't breakable, complain.
3818 if ($dbline[$lineno] == 0) {
3820 "Line $lineno($dbline[$lineno]) does not have an action?\n";
3823 # It's executable. Record that the line has an action.
3824 $had_breakpoints{$filename} |= 2;
3826 # Remove any action, temp breakpoint, etc.
3827 $dbline{$lineno} =~ s/\0[^\0]*//;
3829 # Add the action to the line.
3830 $dbline{$lineno} .= "\0" . action($expr);
3832 } ## end if (length $expr)
3833 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
3837 "Adding an action requires an optional lineno and an expression\n"
3842 =head3 C<cmd_A> (command)
3844 Delete actions. Similar to above, except the delete code is in a separate
3845 subroutine, C<delete_action>.
3850 my $cmd = shift; # A
3851 my $line = shift || '';
3855 $line =~ s/^\./$dbline/;
3857 # Call delete_action with a null param to delete them all.
3858 # The '1' forces the eval to be true. It'll be false only
3859 # if delete_action blows up for some reason, in which case
3860 # we print $@ and get out.
3862 eval { &delete_action(); 1 } or print $OUT $@ and return;
3865 # There's a real line number. Pass it to delete_action.
3866 # Error trapping is as above.
3867 elsif ($line =~ /^(\S.*)/) {
3868 eval { &delete_action($1); 1 } or print $OUT $@ and return;
3871 # Swing and a miss. Bad syntax.
3874 "Deleting an action requires a line number, or '*' for all\n"
3879 =head3 C<delete_action> (API)
3881 C<delete_action> accepts either a line number or C<undef>. If a line number
3882 is specified, we check for the line being executable (if it's not, it
3883 couldn't have had an action). If it is, we just take the action off (this
3884 will get any kind of an action, including breakpoints).
3892 die "Line $i has no action .\n" if $dbline[$i] == 0;
3894 # Nuke whatever's there.
3895 $dbline{$i} =~ s/\0[^\0]*//; # \^a
3896 delete $dbline{$i} if $dbline{$i} eq '';
3899 print $OUT "Deleting all actions...\n";
3900 for my $file (keys %had_breakpoints) {
3901 local *dbline = $main::{'_<' . $file};
3904 for ($i = 1; $i <= $max ; $i++) {
3905 if (defined $dbline{$i}) {
3906 $dbline{$i} =~ s/\0[^\0]*//;
3907 delete $dbline{$i} if $dbline{$i} eq '';
3909 unless ($had_breakpoints{$file} &= ~2) {
3910 delete $had_breakpoints{$file};
3912 } ## end for ($i = 1 ; $i <= $max...
3913 } ## end for my $file (keys %had_breakpoints)
3914 } ## end else [ if (defined($i))
3915 } ## end sub delete_action
3917 =head3 C<cmd_b> (command)
3919 Set breakpoints. Since breakpoints can be set in so many places, in so many
3920 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
3921 we try to parse the command type, and then shuttle it off to an appropriate
3922 subroutine to actually do the work of setting the breakpoint in the right
3928 my $cmd = shift; # b
3929 my $line = shift; # [.|line] [cond]
3932 # Make . the current line number if it's there..
3933 $line =~ s/^\./$dbline/;
3935 # No line number, no condition. Simple break on current line.
3936 if ($line =~ /^\s*$/) {
3937 &cmd_b_line($dbline, 1);
3940 # Break on load for a file.
3941 elsif ($line =~ /^load\b\s*(.*)/) {
3947 # b compile|postpone <some sub> [<condition>]
3948 # The interpreter actually traps this one for us; we just put the
3949 # necessary condition in the %postponed hash.
3950 elsif ($line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/) {
3951 # Capture the condition if there is one. Make it true if none.
3952 my $cond = length $3 ? $3 : '1';
3954 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
3955 # if it was 'compile'.
3956 my ($subname, $break) = ($2, $1 eq 'postpone');
3958 # De-Perl4-ify the name - ' separators to ::.
3959 $subname =~ s/\'/::/g;
3961 # Qualify it into the current package unless it's already qualified.
3962 $subname = "${'package'}::" . $subname unless $subname =~ /::/;
3964 # Add main if it starts with ::.
3965 $subname = "main".$subname if substr($subname,0,2) eq "::";
3967 # Save the break type for this sub.
3968 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
3969 } ## end elsif ($line =~ ...
3971 # b <sub name> [<condition>]
3972 elsif ($line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/) {
3975 $cond = length $2 ? $2 : '1';
3976 &cmd_b_sub($subname, $cond);
3979 # b <line> [<condition>].
3980 elsif ($line =~ /^(\d*)\s*(.*)/) {
3981 # Capture the line. If none, it's the current line.
3982 $line = $1 || $dbline;
3984 # If there's no condition, make it '1'.
3985 $cond = length $2 ? $2 : '1';
3988 &cmd_b_line($line, $cond);
3991 # Line didn't make sense.
3993 print "confused by line($line)?\n";
3997 =head3 C<break_on_load> (API)
3999 We want to break when this file is loaded. Mark this file in the
4000 C<%break_on_load> hash, and note that it has a breakpoint in
4001 C<%had_breakpoints>.
4009 $break_on_load{$file} = 1;
4010 $had_breakpoints{$file} |= 1;
4013 =head3 C<report_break_on_load> (API)
4015 Gives us an array of filenames that are set to break on load. Note that
4016 only files with break-on-load are in here, so simply showing the keys
4021 sub report_break_on_load {
4022 sort keys %break_on_load;
4025 =head3 C<cmd_b_load> (command)
4027 We take the file passed in and try to find it in C<%INC> (which maps modules
4028 to files they came from). We mark those files for break-on-load via
4029 C<break_on_load> and then report that it was done.
4037 # This is a block because that way we can use a redo inside it
4038 # even without there being any looping structure at all outside it.
4040 # Save short name and full path if found.
4042 push @files, $::INC{$file} if $::INC{$file};
4044 # Tack on .pm and do it again unless there was a '.' in the name
4046 $file .= '.pm', redo unless $file =~ /\./;
4049 # Do the real work here.
4050 break_on_load($_) for @files;
4052 # All the files that have break-on-load breakpoints.
4053 @files = report_break_on_load;
4055 # Normalize for the purposes of our printing this.
4058 print $OUT "Will stop on load of `@files'.\n";
4061 =head3 C<$filename_error> (API package global)
4063 Several of the functions we need to implement in the API need to work both
4064 on the current file and on other files. We don't want to duplicate code, so
4065 C<$filename_error> is used to contain the name of the file that's being
4066 worked on (if it's not the current one).
4068 We can now build functions in pairs: the basic function works on the current
4069 file, and uses C<$filename_error> as part of its error message. Since this is
4070 initialized to C<''>, no filename will appear when we are working on the
4073 The second function is a wrapper which does the following:
4077 =item * Localizes C<$filename_error> and sets it to the name of the file to be processed.
4079 =item * Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4081 =item * Calls the first function.
4083 The first function works on the "current" (i.e., the one we changed to) file,
4084 and prints C<$filename_error> in the error message (the name of the other file)
4085 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
4086 restored to C<''>. This restores everything to the way it was before the
4087 second function was called at all.
4089 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4096 $filename_error = '';
4098 =head3 breakable_line($from, $to) (API)
4100 The subroutine decides whether or not a line in the current file is breakable.
4101 It walks through C<@dbline> within the range of lines specified, looking for
4102 the first line that is breakable.
4104 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4105 first line I<after> C<$to> that's breakable, if there is one.
4107 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4108 first line I<before> C<$to> that's breakable, if there is one.
4112 sub breakable_line {
4114 my ($from, $to) = @_;
4116 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4119 # If there are at least 2 arguments, we're trying to search a range.
4122 # $delta is positive for a forward search, negative for a backward one.
4123 my $delta = $from < $to ? +1 : -1;
4125 # Keep us from running off the ends of the file.
4126 my $limit = $delta > 0 ? $#dbline : 1;
4128 # Clever test. If you're a mathematician, it's obvious why this
4129 # test works. If not:
4130 # If $delta is positive (going forward), $limit will be $#dbline.
4131 # If $to is less than $limit, ($limit - $to) will be positive, times
4132 # $delta of 1 (positive), so the result is > 0 and we should use $to
4133 # as the stopping point.
4135 # If $to is greater than $limit, ($limit - $to) is negative,
4136 # times $delta of 1 (positive), so the result is < 0 and we should
4137 # use $limit ($#dbline) as the stopping point.
4139 # If $delta is negative (going backward), $limit will be 1.
4140 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4141 # (negative) so the result is > 0, and we use $to as the stopping
4144 # If $to is less than zero, ($limit - $to) will be positive,
4145 # times $delta of -1 (negative), so the result is not > 0, and
4146 # we use $limit (1) as the stopping point.
4148 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4149 # (negative), still giving zero; the result is not > 0, and
4150 # we use $limit (1) as the stopping point.
4152 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4153 # (negative), giving a positive (>0) value, so we'll set $limit to
4156 $limit = $to if ($limit - $to) * $delta > 0;
4158 # The real search loop.
4159 # $i starts at $from (the point we want to start searching from).
4160 # We move through @dbline in the appropriate direction (determined
4161 # by $delta: either -1 (back) or +1 (ahead).
4162 # We stay in as long as we haven't hit an executable line
4163 # ($dbline[$i] == 0 means not executable) and we haven't reached
4164 # the limit yet (test similar to the above).
4165 $i += $delta while $dbline[$i] == 0 and ($limit - $i) * $delta > 0;
4166 } ## end if (@_ >= 2)
4168 # If $i points to a line that is executable, return that.
4169 return $i unless $dbline[$i] == 0;
4171 # Format the message and print it: no breakable lines in range.
4172 my ($pl, $upto) = ('', '');
4173 my ($pl, $upto) = ('', '');
4174 ($pl, $upto) = ('s', "..$to") if @_ >=2 and $from != $to;
4176 # If there's a filename in filename_error, we'll see it.
4178 die "Line$pl $from$upto$filename_error not breakable\n";
4179 } ## end sub breakable_line
4181 =head3 breakable_line_in_filename($file, $from, $to) (API)
4183 Like C<breakable_line>, but look in another file.
4187 sub breakable_line_in_filename {
4188 # Capture the file name.
4191 # Swap the magic line array over there temporarily.
4192 local *dbline = $main::{'_<' . $f};
4194 # If there's an error, it's in this other file.
4195 local $filename_error = " of `$f'";
4197 # Find the breakable line.
4200 # *dbline and $filename_error get restored when this block ends.
4202 } ## end sub breakable_line_in_filename
4204 =head3 break_on_line(lineno, [condition]) (API)
4206 Adds a breakpoint with the specified condition (or 1 if no condition was
4207 specified) to the specified line. Dies if it can't.
4212 my ($i, $cond) = @_;
4214 # Always true if no condition supplied.
4215 $cond = 1 unless @_ >= 2;
4221 # Woops, not a breakable line. $filename_error allows us to say
4222 # if it was in a different file.
4223 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4225 # Mark this file as having breakpoints in it.
4226 $had_breakpoints{$filename} |= 1;
4228 # If there is an action or condition here already ...
4230 # ... swap this condition for the existing one.
4231 $dbline{$i} =~ s/^[^\0]*/$cond/;
4234 # Nothing here - just add the condition.
4235 $dbline{$i} = $cond;
4237 } ## end sub break_on_line
4239 =head3 cmd_b_line(line, [condition]) (command)
4241 Wrapper for C<break_on_line>. Prints the failure message if it
4247 eval { break_on_line(@_); 1 } or do {
4249 print $OUT $@ and return;
4251 } ## end sub cmd_b_line
4253 =head3 break_on_filename_line(file, line, [condition]) (API)
4255 Switches to the file specified and then calls C<break_on_line> to set
4260 sub break_on_filename_line {
4261 my ($f, $i, $cond) = @_;
4263 # Always true if condition left off.
4264 $cond = 1 unless @_ >= 3;
4266 # Switch the magical hash temporarily.
4267 local *dbline = $main::{'_<' . $f};
4269 # Localize the variables that break_on_line uses to make its message.
4270 local $filename_error = " of `$f'";
4271 local $filename = $f;
4273 # Add the breakpoint.
4274 break_on_line($i, $cond);
4275 } ## end sub break_on_filename_line
4277 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4279 Switch to another file, search the range of lines specified for an
4280 executable one, and put a breakpoint on the first one you find.
4284 sub break_on_filename_line_range {
4285 my ($f, $from, $to, $cond) = @_;
4287 # Find a breakable line if there is one.
4288 my $i = breakable_line_in_filename($f, $from, $to);
4290 # Find a breakable line if there is one.
4291 $cond = 1 unless @_ >= 3;
4293 # Add the breakpoint.
4294 break_on_filename_line($f,$i,$cond);
4295 } ## end sub break_on_filename_line_range
4297 =head3 subroutine_filename_lines(subname, [condition]) (API)
4299 Search for a subroutine within a given file. The condition is ignored.
4300 Uses C<find_sub> to locate the desired subroutine.
4304 sub subroutine_filename_lines {
4305 my ($subname,$cond) = @_;
4307 # Returned value from find_sub() is fullpathname:startline-endline.
4308 # The match creates the list (fullpathname, start, end). Falling off
4309 # the end of the subroutine returns this implicitly.
4310 find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/;
4311 } ## end sub subroutine_filename_lines
4313 =head3 break_subroutine(subname) (API)
4315 Places a break on the first line possible in the specified subroutine. Uses
4316 C<subroutine_filename_lines> to find the subroutine, and
4317 C<break_on_filename_line_range> to place the break.
4321 sub break_subroutine {
4322 my $subname = shift;
4324 # Get filename, start, and end.
4325 my ($file,$s,$e) = subroutine_filename_lines($subname)
4326 or die "Subroutine $subname not found.\n";
4328 # Null condition changes to '1' (always true).
4329 $cond = 1 unless @_ >= 2;
4331 # Put a break the first place possible in the range of lines
4332 # that make up this subroutine.
4333 break_on_filename_line_range($file,$s,$e,@_);
4334 } ## end sub break_subroutine
4336 =head3 cmd_b_sub(subname, [condition]) (command)
4338 We take the incoming subroutine name and fully-qualify it as best we can.
4342 =item 1. If it's already fully-qualified, leave it alone.
4344 =item 2. Try putting it in the current package.
4346 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
4348 =item 4. If it starts with '::', put it in 'main::'.
4352 After all this cleanup, we call C<break_subroutine> to try to set the
4358 my ($subname,$cond) = @_;
4360 # Add always-true condition if we have none.
4361 $cond = 1 unless @_ >= 2;
4363 # If the subname isn't a code reference, qualify it so that
4364 # break_subroutine() will work right.
4365 unless (ref $subname eq 'CODE') {
4367 $subname =~ s/\'/::/g;
4370 # Put it in this package unless it's already qualified.
4371 $subname = "${'package'}::" . $subname
4372 unless $subname =~ /::/;
4374 # Requalify it into CORE::GLOBAL if qualifying it into this
4375 # package resulted in its not being defined, but only do so
4376 # if it really is in CORE::GLOBAL.
4377 $subname = "CORE::GLOBAL::$s"
4378 if not defined &$subname
4380 and defined &{"CORE::GLOBAL::$s"};
4382 # Put it in package 'main' if it has a leading ::.
4383 $subname = "main".$subname if substr($subname,0,2) eq "::";
4385 } ## end unless (ref $subname eq 'CODE')
4387 # Try to set the breakpoint.
4388 eval { break_subroutine($subname,$cond); 1 } or do {
4390 print $OUT $@ and return;
4392 } ## end sub cmd_b_sub
4394 =head3 C<cmd_B> - delete breakpoint(s) (command)
4396 The command mostly parses the command line and tries to turn the argument
4397 into a line spec. If it can't, it uses the current line. It then calls
4398 C<delete_breakpoint> to actually do the work.
4400 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
4401 thereby deleting all the breakpoints.
4408 # No line spec? Use dbline.
4409 # If there is one, use it if it's non-zero, or wipe it out if it is.
4410 my $line = ($_[0] =~ /^\./) ? $dbline : shift || '';
4413 # If the line was dot, make the line the current one.
4414 $line =~ s/^\./$dbline/;
4416 # If it's * we're deleting all the breakpoints.
4418 eval { &delete_breakpoint(); 1 } or print $OUT $@ and return;
4421 # If there is a line spec, delete the breakpoint on that line.
4422 elsif ($line =~ /^(\S.*)/) {
4423 eval { &delete_breakpoint($line || $dbline); 1 } or do {
4425 print $OUT $@ and return;
4427 } ## end elsif ($line =~ /^(\S.*)/)
4432 "Deleting a breakpoint requires a line number, or '*' for all\n"
4437 =head3 delete_breakpoint([line]) (API)
4439 This actually does the work of deleting either a single breakpoint, or all
4442 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
4443 just drop out with a message saying so. If it is, we remove the condition
4444 part of the 'condition\0action' that says there's a breakpoint here. If,
4445 after we've done that, there's nothing left, we delete the corresponding
4446 line in C<%dbline> to signal that no action needs to be taken for this line.
4448 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
4449 which lists all currently-loaded files which have breakpoints. We then look
4450 at each line in each of these files, temporarily switching the C<%dbline>
4451 and C<@dbline> structures to point to the files in question, and do what
4452 we did in the single line case: delete the condition in C<@dbline>, and
4453 delete the key in C<%dbline> if nothing's left.
4455 We then wholesale delete C<%postponed>, C<%postponed_file>, and
4456 C<%break_on_load>, because these structures contain breakpoints for files
4457 and code that haven't been loaded yet. We can just kill these off because there
4458 are no magical debugger structures associated with them.
4462 sub delete_breakpoint {
4465 # If we got a line, delete just that one.
4468 # Woops. This line wasn't breakable at all.
4469 die "Line $i not breakable.\n" if $dbline[$i] == 0;
4471 # Kill the condition, but leave any action.
4472 $dbline{$i} =~ s/^[^\0]*//;
4474 # Remove the entry entirely if there's no action left.
4475 delete $dbline{$i} if $dbline{$i} eq '';
4478 # No line; delete them all.
4480 print $OUT "Deleting all breakpoints...\n";
4482 # %had_breakpoints lists every file that had at least one
4484 for my $file (keys %had_breakpoints) {
4485 # Switch to the desired file temporarily.
4486 local *dbline = $main::{'_<' . $file};
4491 # For all lines in this file ...
4492 for ($i = 1; $i <= $max ; $i++) {
4493 # If there's a breakpoint or action on this line ...
4494 if (defined $dbline{$i}) {
4495 # ... remove the breakpoint.
4496 $dbline{$i} =~ s/^[^\0]+//;
4497 if ($dbline{$i} =~ s/^\0?$//) {
4498 # Remove the entry altogether if no action is there.
4501 } ## end if (defined $dbline{$i...
4502 } ## end for ($i = 1 ; $i <= $max...
4504 # If, after we turn off the "there were breakpoints in this file"
4505 # bit, the entry in %had_breakpoints for this file is zero,
4506 # we should remove this file from the hash.
4507 if (not $had_breakpoints{$file} &= ~1) {
4508 delete $had_breakpoints{$file};
4510 } ## end for my $file (keys %had_breakpoints)
4512 # Kill off all the other breakpoints that are waiting for files that
4513 # haven't been loaded yet.
4515 undef %postponed_file;
4516 undef %break_on_load;
4517 } ## end else [ if (defined($i))
4518 } ## end sub delete_breakpoint
4520 =head3 cmd_stop (command)
4522 This is meant to be part of the new command API, but it isn't called or used
4523 anywhere else in the debugger. XXX It is probably meant for use in development
4528 sub cmd_stop { # As on ^C, but not signal-safy.
4532 sub cmd_stop { # As on ^C, but not signal-safy.
4536 =head3 C<cmd_h> - help command (command)
4538 Does the work of either
4542 =item * Showing all the debugger help
4544 =item * Showing help for a specific command
4554 # If we have no operand, assume null.
4555 my $line = shift || '';
4557 # 'h h'. Print the long-format help.
4558 if ($line =~ /^h\s*/) {
4562 # 'h <something>'. Search for the command and print only its help.
4563 elsif ($line =~ /^(\S.*)$/) {
4565 # support long commands; otherwise bogus errors
4566 # happen when you ask for h on <CR> for example
4567 my $asked = $1; # the command requested
4568 # (for proper error message)
4570 my $qasked = quotemeta($asked); # for searching; we don't
4571 # want to use it as a pattern.
4572 # XXX: finds CR but not <CR>
4574 # Search the help string for the command.
4575 if ($help =~ /^ # Start of a line
4577 (?:[IB]<) # Optional markup
4578 $qasked # The requested command
4580 # It's there; pull it out and print it.
4583 (?:[IB]<) # Optional markup
4584 $qasked # The command
4585 ([\s\S]*?) # Description line(s)
4586 \n) # End of last description line
4587 (?!\s) # Next line not starting with
4594 # Not found; not a debugger command.
4596 print_help("B<$asked> is not a debugger command.\n");
4598 } ## end elsif ($line =~ /^(\S.*)$/)
4600 # 'h' - print the summary help.
4602 print_help($summary);
4606 =head3 C<cmd_i> - inheritance display
4608 Display the (nested) parentage of the module or object given.
4615 eval { require Class::ISA };
4617 &warn($@ =~ /locate/ ? "Class::ISA module not found - please install\n" : $@);
4620 foreach my $isa (split(/\s+/, $line)) {
4622 print join(', ', map { # snaffled unceremoniously from Class::ISA
4623 "$_".(defined(${"$_\::VERSION"}) ? ' '.${"$_\::VERSION"} : undef)
4624 } Class::ISA::self_and_super_path($isa));
4630 =head3 C<cmd_l> - list lines (command)
4632 Most of the command is taken up with transforming all the different line
4633 specification syntaxes into 'start-stop'. After that is done, the command
4634 runs a loop over C<@dbline> for the specified range of lines. It handles
4635 the printing of each line and any markers (C<==E<gt>> for current line,
4636 C<b> for break on this line, C<a> for action on this line, C<:> for this
4639 We save the last line listed in the C<$start> global for further listing
4645 my $current_line = $line;
4649 # If this is '-something', delete any spaces after the dash.
4650 $line =~ s/^-\s*$/-/;
4652 # If the line is '$something', assume this is a scalar containing a
4654 if ($line =~ /^(\$.*)/s) {
4656 # Set up for DB::eval() - evaluate in *user* context.
4661 # Ooops. Bad scalar.
4662 print($OUT "Error: $@\n"), next CMD if $@;
4664 # Good scalar. If it's a reference, find what it points to.
4666 print($OUT "Interpreted as: $1 $s\n");
4669 # Call self recursively to really do the command.
4671 } ## end if ($line =~ /^(\$.*)/s)
4673 # l name. Try to find a sub by that name.
4674 elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s) {
4675 my $s = $subname = $1;
4678 $subname =~ s/\'/::/;
4680 # Put it in this package unless it starts with ::.
4681 $subname = $package."::".$subname unless $subname =~ /::/;
4683 # Put it in CORE::GLOBAL if t doesn't start with :: and
4684 # it doesn't live in this package and it lives in CORE::GLOBAL.
4685 $subname = "CORE::GLOBAL::$s"
4686 if not defined &$subname
4688 and defined &{"CORE::GLOBAL::$s"};
4690 # Put leading '::' names into 'main::'.
4691 $subname = "main".$subname if substr($subname,0,2) eq "::";
4693 # Get name:start-stop from find_sub, and break this up at
4695 @pieces = split(/:/,find_sub($subname) || $sub{$subname});
4697 # Pull off start-stop.
4698 $subrange = pop @pieces;
4700 # If the name contained colons, the split broke it up.
4701 # Put it back together.
4702 $file = join(':', @pieces);
4704 # If we're not in that file, switch over to it.
4705 if ($file ne $filename) {
4706 print $OUT "Switching to file '$file'.\n"
4707 unless $slave_editor;
4709 # Switch debugger's magic structures.
4710 *dbline = $main::{'_<' . $file};
4713 } ## end if ($file ne $filename)
4715 # Subrange is 'start-stop'. If this is less than a window full,
4716 # swap it to 'start+', which will list a window from the start point.
4718 if (eval($subrange) < -$window) {
4719 $subrange =~ s/-.*/+/;
4721 # Call self recursively to list the range.
4723 &cmd_l('l', $subrange);
4724 } ## end if ($subrange)
4728 print $OUT "Subroutine $subname not found.\n";
4730 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s)
4733 elsif ($line =~ /^\s*$/) {
4734 # Compute new range to list.
4735 $incr = $window - 1;
4736 $line = $start . '-' . ($start + $incr);
4741 # l [start]+number_of_lines
4742 elsif ($line =~ /^(\d*)\+(\d*)$/) {
4743 # Don't reset start for 'l +nnn'.
4746 # Increment for list. Use window size if not specified.
4747 # (Allows 'l +' to work.)
4749 $incr = $window - 1 unless $incr;
4751 # Create a line range we'll understand, and recurse to do it.
4752 $line = $start . '-' . ($start + $incr);
4754 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/)
4756 # l start-stop or l start,stop
4757 elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/) {
4759 # Determine end point; use end of file if not specified.
4760 $end = (!defined $2) ? $max : ($4 ? $4 : $2);
4762 # Go on to the end, and then stop.
4763 $end = $max if $end > $max;
4765 # Determine start line.
4767 $i = $line if $i eq '.';
4771 # If we're running under a slave editor, force it to show the lines.
4772 if ($slave_editor) {
4773 print $OUT "\032\032$filename:$i:0\n";
4777 # We're doing it ourselves. We want to show the line and special
4779 # - the current line in execution
4780 # - whether a line is breakable or not
4781 # - whether a line has a break or not
4782 # - whether a line has an action or not
4784 for (; $i <= $end; $i++) {
4785 # Check for breakpoints and actions.
4787 ($stop,$action) = split(/\0/, $dbline{$i})
4790 # ==> if this is the current line in execution,
4791 # : if it's breakable.
4792 $arrow = ($i==$current_line and $filename eq $filename_ini)
4794 : ($dbline[$i]+0 ? ':' : ' ');
4796 # Add break and action indicators.
4797 $arrow .= 'b' if $stop;
4798 $arrow .= 'a' if $action;
4801 print $OUT "$i$arrow\t", $dbline[$i];
4803 # Move on to the next line. Drop out on an interrupt.
4804 $i++, last if $signal;
4805 } ## end for (; $i <= $end ; $i++)
4807 # Line the prompt up; print a newline if the last line listed
4808 # didn't have a newline.
4809 print $OUT "\n" unless $dbline[$i-1] =~ /\n$/;
4810 } ## end else [ if ($slave_editor)
4812 # Save the point we last listed to in case another relative 'l'
4813 # command is desired. Don't let it run off the end.
4815 $start = $max if $start > $max;
4816 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/)
4819 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
4821 To list breakpoints, the command has to look determine where all of them are
4822 first. It starts a C<%had_breakpoints>, which tells us what all files have
4823 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
4824 magic source and breakpoint data structures) to the file, and then look
4825 through C<%dbline> for lines with breakpoints and/or actions, listing them
4826 out. We look through C<%postponed> not-yet-compiled subroutines that have
4827 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
4828 that have breakpoints.
4830 Watchpoints are simpler: we just list the entries in C<@to_watch>.
4837 # If no argument, list everything. Pre-5.8.0 version always lists
4839 my $arg = shift || 'abw';
4840 $arg = 'abw' unless $CommandSet eq '580'; # sigh...
4842 # See what is wanted.
4843 my $action_wanted = ($arg =~ /a/) ? 1 : 0;
4844 my $break_wanted = ($arg =~ /b/) ? 1 : 0;
4845 my $watch_wanted = ($arg =~ /w/) ? 1 : 0;
4847 # Breaks and actions are found together, so we look in the same place
4849 if ($break_wanted or $action_wanted) {
4850 # Look in all the files with breakpoints...
4851 for my $file (keys %had_breakpoints) {
4852 # Temporary switch to this file.
4853 local *dbline = $main::{ '_<' . $file };
4855 # Set up to look through the whole file.
4857 my $was; # Flag: did we print something
4860 # For each line in the file ...
4861 for ($i = 1; $i <= $max ; $i++) {
4862 # We've got something on this line.
4863 if (defined $dbline{$i}) {
4864 # Print the header if we haven't.
4865 print $OUT "$file:\n" unless $was++;
4868 print $OUT " $i:\t", $dbline[$i];
4870 # Pull out the condition and the action.
4871 ($stop, $action) = split (/\0/, $dbline{$i});
4873 # Print the break if there is one and it's wanted.
4874 print $OUT " break if (", $stop, ")\n"
4878 # Print the action if there is one and it's wanted.
4879 print $OUT " action: ", $action, "\n"
4883 # Quit if the user hit interrupt.
4885 } ## end if (defined $dbline{$i...
4886 } ## end for ($i = 1 ; $i <= $max...
4887 } ## end for my $file (keys %had_breakpoints)
4888 } ## end if ($break_wanted or $action_wanted)
4890 # Look for breaks in not-yet-compiled subs:
4891 if (%postponed and $break_wanted) {
4892 print $OUT "Postponed breakpoints in subroutines:\n";
4894 for $subname (keys %postponed) {
4895 print $OUT " $subname\t$postponed{$subname}\n";
4898 } ## end if (%postponed and $break_wanted)
4900 # Find files that have not-yet-loaded breaks:
4901 my @have = map { # Combined keys
4902 keys %{$postponed_file{$_}}
4903 } keys %postponed_file;
4905 # If there are any, list them.
4906 if (@have and ($break_wanted or $action_wanted)) {
4907 print $OUT "Postponed breakpoints in files:\n";
4910 for $file (keys %postponed_file) {
4911 my $db = $postponed_file{$file};
4912 print $OUT " $file:\n";
4913 for $line (sort { $a <=> $b } keys %$db) {
4914 print $OUT " $line:\n";
4915 my ($stop, $action) = split (/\0/, $$db{$line});
4916 print $OUT " break if (", $stop, ")\n"
4919 print $OUT " action: ", $action, "\n"
4923 } ## end for $line (sort { $a <=>...
4925 } ## end for $file (keys %postponed_file)
4926 } ## end if (@have and ($break_wanted...
4927 if (%break_on_load and $break_wanted) {
4928 print $OUT "Breakpoints on load:\n";
4930 for $file (keys %break_on_load) {
4931 print $OUT " $file\n";
4934 } ## end if (%break_on_load and...
4935 if ($watch_wanted) {
4937 print $OUT "Watch-expressions:\n" if @to_watch;
4938 for my $expr (@to_watch) {
4939 print $OUT " $expr\n";
4942 } ## end if ($trace & 2)
4943 } ## end if ($watch_wanted)
4946 =head3 C<cmd_M> - list modules (command)
4948 Just call C<list_modules>.
4956 =head3 C<cmd_o> - options (command)
4958 If this is just C<o> by itself, we list the current settings via
4959 C<dump_option>. If there's a nonblank value following it, we pass that on to
4960 C<parse_options> for processing.
4966 my $opt = shift || ''; # opt[=val]
4968 # Nonblank. Try to parse and process.
4969 if ($opt =~ /^(\S.*)/) {
4973 # Blank. List the current option settings.
4981 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
4983 Advises the user that the O command has been renamed.
4988 print $OUT "The old O command is now the o command.\n"; # hint
4989 print $OUT "Use 'h' to get current command help synopsis or\n"; #
4990 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
4993 =head3 C<cmd_v> - view window (command)
4995 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
4996 move back a few lines to list the selected line in context. Uses C<cmd_l>
4997 to do the actual listing after figuring out the range of line to request.
5005 # Extract the line to list around. (Astute readers will have noted that
5006 # this pattern will match whether or not a numeric line is specified,
5007 # which means that we'll always enter this loop (though a non-numeric
5008 # argument results in no action at all)).
5009 if ($line =~ /^(\d*)$/) {
5010 # Total number of lines to list (a windowful).
5011 $incr = $window - 1;
5013 # Set the start to the argument given (if there was one).
5016 # Back up by the context amount.
5019 # Put together a linespec that cmd_l will like.
5020 $line = $start . '-' . ($start + $incr);
5024 } ## end if ($line =~ /^(\d*)$/)
5027 =head3 C<cmd_w> - add a watch expression (command)
5029 The 5.8 version of this command adds a watch expression if one is specified;
5030 it does nothing if entered with no operands.
5032 We extract the expression, save it, evaluate it in the user's context, and
5033 save the value. We'll re-evaluate it each time the debugger passes a line,
5034 and will stop (see the code at the top of the command loop) if the value
5035 of any of the expressions changes.
5042 # Null expression if no arguments.
5043 my $expr = shift || '';
5045 # If expression is not null ...
5046 if ($expr =~ /^(\S.*)/) {
5048 push @to_watch, $expr;
5050 # Parameterize DB::eval and call it to get the expression's value
5051 # in the user's context. This version can handle expressions which
5052 # return a list value.
5054 my ($val) = join(' ', &eval);
5055 $val = (defined $val) ? "'$val'" : 'undef';
5057 # Save the current value of the expression.
5058 push @old_watch, $val;
5060 # We are now watching expressions.
5062 } ## end if ($expr =~ /^(\S.*)/)
5064 # You have to give one to get one.
5067 "Adding a watch-expression requires an expression\n"; # hint
5071 =head3 C<cmd_W> - delete watch expressions (command)
5073 This command accepts either a watch expression to be removed from the list
5074 of watch expressions, or C<*> to delete them all.
5076 If C<*> is specified, we simply empty the watch expression list and the
5077 watch expression value list. We also turn off the bit that says we've got
5080 If an expression (or partial expression) is specified, we pattern-match
5081 through the expressions and remove the ones that match. We also discard
5082 the corresponding values. If no watch expressions are left, we turn off
5083 the 'watching expressions' bit.
5089 my $expr = shift || '';
5096 print $OUT "Deleting all watch expressions ...\n";
5099 @to_watch = @old_watch = ();
5102 # Delete one of them.
5103 elsif ($expr =~ /^(\S.*)/) {
5104 # Where we are in the list.
5107 # For each expression ...
5108 foreach (@to_watch) {
5109 my $val = $to_watch[$i_cnt];
5111 # Does this one match the command argument?
5112 if ($val eq $expr) { # =~ m/^\Q$i$/) {
5113 splice(@to_watch, $i_cnt, 1);
5116 } ## end foreach (@to_watch)
5118 # We don't bother to turn watching off because
5119 # a) we don't want to stop calling watchfunction() it it exists
5120 # b) foreach over a null list doesn't do anything anyway
5122 } ## end elsif ($expr =~ /^(\S.*)/)
5126 "Deleting a watch-expression requires an expression, or '*' for all\n"
5131 ### END of the API section
5133 =head1 SUPPORT ROUTINES
5135 These are general support routines that are used in a number of places
5136 throughout the debugger.
5140 Something to do with assertions
5145 if ($cmd =~ /^.\b\s*([+-]?)\s*(~?)\s*(\w+(\s*\|\s*\w+)*)\s*$/) {
5146 my ($how, $neg, $flags)=($1, $2, $3);
5147 my $acu=parse_DollarCaretP_flags($flags);
5149 $acu= ~$acu if $neg;
5150 if ($how eq '+') { $^P|=$acu }
5151 elsif ($how eq '-') { $^P&=~$acu }
5154 # else { print $OUT "undefined acu\n" }
5156 my $expanded=expand_DollarCaretP_flags($^P);
5157 print $OUT "Internal Perl debugger flags:\n\$^P=$expanded\n";
5163 save() saves the user's versions of globals that would mess us up in C<@saved>,
5164 and installs the versions we like better.
5169 # Save eval failure, command failure, extended OS error, output field
5170 # separator, input record separator, output record separator and
5171 # the warning setting.
5172 @saved = ($@, $!, $^E, $,, $/, $\, $^W);
5174 $, = ""; # output field separator is null string
5175 $/ = "\n"; # input record separator is newline
5176 $\ = ""; # output record separator is null string
5177 $^W = 0; # warnings are off
5180 =head2 C<print_lineinfo> - show where we are now
5182 print_lineinfo prints whatever it is that it is handed; it prints it to the
5183 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
5184 us to feed line information to a slave editor without messing up the
5189 sub print_lineinfo {
5190 # Make the terminal sensible if we're not the primary debugger.
5191 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
5195 } ## end sub print_lineinfo
5197 =head2 C<postponed_sub>
5199 Handles setting postponed breakpoints in subroutines once they're compiled.
5200 For breakpoints, we use C<DB::find_sub> to locate the source file and line
5201 range for the subroutine, then mark the file as having a breakpoint,
5202 temporarily switch the C<*dbline> glob over to the source file, and then
5203 search the given range of lines to find a breakable line. If we find one,
5204 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
5208 # The following takes its argument via $evalarg to preserve current @_
5211 # Get the subroutine name.
5212 my $subname = shift;
5214 # If this is a 'break +<n> if <condition>' ...
5215 if ($postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s//) {
5216 # If there's no offset, use '+0'.
5217 my $offset = $1 || 0;
5219 # find_sub's value is 'fullpath-filename:start-stop'. It's
5220 # possible that the filename might have colons in it too.
5221 my ($file,$i) = (find_sub($subname) =~ /^(.*):(\d+)-.*$/);
5223 # We got the start line. Add the offset '+<n>' from
5224 # $postponed{subname}.
5227 # Switch to the file this sub is in, temporarily.
5228 local *dbline = $main::{'_<' . $file};
5230 # No warnings, please.
5231 local $^W = 0; # != 0 is magical below
5233 # This file's got a breakpoint in it.
5234 $had_breakpoints{$file} |= 1;
5236 # Last line in file.
5239 # Search forward until we hit a breakable line or get to
5240 # the end of the file.
5241 ++$i until $dbline[$i] != 0 or $i >= $max;
5243 # Copy the breakpoint in and delete it from %postponed.
5244 $dbline{$i} = delete $postponed{$subname};
5247 # find_sub didn't find the sub.
5250 print $OUT "Subroutine $subname not found.\n";
5254 elsif ($postponed{$subname} eq 'compile') { $signal = 1 }
5255 #print $OUT "In postponed_sub for `$subname'.\n";
5260 Called after each required file is compiled, but before it is executed;
5261 also called if the name of a just-compiled subroutine is a key of
5262 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
5263 etc.) into the just-compiled code.
5265 If this is a C<require>'d file, the incoming parameter is the glob
5266 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
5268 If it's a subroutine, the incoming parameter is the subroutine name.
5273 # If there's a break, process it.
5274 if ($ImmediateStop) {
5275 # Right, we've stopped. Turn it off.
5278 # Enter the command loop when DB::DB gets called.
5282 # If this is a subroutine, let postponed_sub() deal with it.
5283 return &postponed_sub unless ref \$_[0] eq 'GLOB'; # A subroutine is compiled.
5285 # Not a subroutine. Deal with the file.
5286 local *dbline = shift;
5287 my $filename = $dbline;
5288 $filename =~ s/^_<//;
5290 $signal = 1, print $OUT "'$filename' loaded...\n"
5291 if $break_on_load{$filename};
5292 print_lineinfo(' ' x $stack_depth, "Package $filename.\n") if $frame;
5294 # Do we have any breakpoints to put in this file?
5295 return unless $postponed_file{$filename};
5297 # Yes. Mark this file as having breakpoints.
5298 $had_breakpoints{$filename} |= 1;
5300 # "Cannot be done: unsufficient magic" - we can't just put the
5301 # breakpoints saved in %postponed_file into %dbline by assigning
5302 # the whole hash; we have to do it one item at a time for the
5303 # breakpoints to be set properly.
5304 #%dbline = %{$postponed_file{$filename}};
5306 # Set the breakpoints, one at a time.
5309 for $key (keys %{ $postponed_file{$filename} }) {
5310 # Stash the saved breakpoint into the current file's magic line array.
5311 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
5314 # This file's been compiled; discard the stored breakpoints.
5315 delete $postponed_file{$filename};
5317 } ## end sub postponed
5321 C<dumpit> is the debugger's wrapper around dumpvar.pl.
5323 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
5324 a reference to a variable (the thing to be dumped) as its input.
5326 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
5327 the currently-selected filehandle, thank you very much). The current
5328 values of the package globals C<$single> and C<$trace> are backed up in
5329 lexicals, and they are turned off (this keeps the debugger from trying
5330 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
5331 preserve its current value and it is set to zero to prevent entry/exit
5332 messages from printing, and C<$doret> is localized as well and set to -2 to
5333 prevent return values from being shown.
5335 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
5336 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
5337 installed version in @INC, yours will be used instead. Possible security
5340 It then checks to see if the subroutine C<main::dumpValue> is now defined
5341 (it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
5342 localizes the globals necessary for things to be sane when C<main::dumpValue()>
5343 is called, and picks up the variable to be dumped from the parameter list.
5345 It checks the package global C<%options> to see if there's a C<dumpDepth>
5346 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
5347 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
5348 structure: -1 means dump everything.
5350 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
5353 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
5354 and we then return to the caller.
5359 # Save the current output filehandle and switch to the one
5360 # passed in as the first parameter.
5361 local ($savout) = select(shift);
5363 # Save current settings of $single and $trace, and then turn them off.
5364 my $osingle = $single;
5365 my $otrace = $trace;
5366 $single = $trace = 0;
5368 # XXX Okay, what do $frame and $doret do, again?
5372 # Load dumpvar.pl unless we've already got the sub we need from it.
5373 unless (defined &main::dumpValue) {
5377 # If the load succeeded (or we already had dumpvalue()), go ahead
5379 if (defined &main::dumpValue) {
5384 my $maxdepth = shift || $option{dumpDepth};
5385 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
5386 &main::dumpValue($v, $maxdepth);
5387 } ## end if (defined &main::dumpValue)
5389 # Oops, couldn't load dumpvar.pl.
5392 print $OUT "dumpvar.pl not available.\n";
5395 # Reset $single and $trace to their old values.
5399 # Restore the old filehandle.
5403 =head2 C<print_trace>
5405 C<print_trace>'s job is to print a stack trace. It does this via the
5406 C<dump_trace> routine, which actually does all the ferreting-out of the
5407 stack trace data. C<print_trace> takes care of formatting it nicely and
5408 printing it to the proper filehandle.
5414 =item * The filehandle to print to.
5416 =item * How many frames to skip before starting trace.
5418 =item * How many frames to print.
5420 =item * A flag: if true, print a "short" trace without filenames, line numbers, or arguments
5424 The original comment below seems to be noting that the traceback may not be
5425 correct if this routine is called in a tied method.
5429 # Tied method do not create a context, so may get wrong message:
5434 # If this is going to a slave editor, but we're not the primary
5435 # debugger, reset it first.
5437 if $fh eq $LINEINFO # slave editor
5438 and $LINEINFO eq $OUT # normal output
5439 and $term_pid != $$; # not the primary
5441 # Collect the actual trace information to be formatted.
5442 # This is an array of hashes of subroutine call info.
5443 my @sub = dump_trace($_[0] + 1, $_[1]);
5445 # Grab the "short report" flag from @_.
5446 my $short = $_[2]; # Print short report, next one for sub name
5448 # Run through the traceback info, format it, and print it.
5450 for ($i=0; $i <= $#sub; $i++) {
5451 # Drop out if the user has lost interest and hit control-C.
5454 # Set the separator so arrys print nice.
5457 # Grab and stringify the arguments if they are there.
5459 defined $sub[$i]{args}
5460 ? "(@{ $sub[$i]{args} })"
5462 # Shorten them up if $maxtrace says they're too long.
5463 $args = (substr $args, 0, $maxtrace - 3) . '...'
5464 if length $args > $maxtrace;
5466 # Get the file name.
5467 my $file = $sub[$i]{file};
5469 # Put in a filename header if short is off.
5470 $file = $file eq '-e' ? $file : "file `$file'" unless $short;
5472 # Get the actual sub's name, and shorten to $maxtrace's requirement.
5474 $s = (substr $s, 0, $maxtrace - 3) . '...' if length $s > $maxtrace;
5476 # Short report uses trimmed file and sub names.
5478 my $sub = @_ >= 4 ? $_[3] : $s;
5480 "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
5481 } ## end if ($short)
5483 # Non-short report includes full names.
5485 print $fh "$sub[$i]{context} = $s$args" . " called from $file" .
5486 " line $sub[$i]{line}\n";
5488 } ## end for ($i = 0 ; $i <= $#sub...
5489 } ## end sub print_trace
5491 =head2 dump_trace(skip[,count])
5493 Actually collect the traceback information available via C<caller()>. It does
5494 some filtering and cleanup of the data, but mostly it just collects it to
5495 make C<print_trace()>'s job easier.
5497 C<skip> defines the number of stack frames to be skipped, working backwards
5498 from the most current. C<count> determines the total number of frames to
5499 be returned; all of them (well, the first 10^9) are returned if C<count>
5502 This routine returns a list of hashes, from most-recent to least-recent
5503 stack frame. Each has the following keys and values:
5507 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
5509 =item * C<sub> - subroutine name, or C<eval> information
5511 =item * C<args> - undef, or a reference to an array of arguments
5513 =item * C<file> - the file in which this item was defined (if any)
5515 =item * C<line> - the line on which it was defined
5523 # How many levels to skip.
5526 # How many levels to show. (1e9 is a cheap way of saying "all of them";
5527 # it's unlikely that we'll have more than a billion stack frames. If you
5528 # do, you've got an awfully big machine...)
5529 my $count = shift || 1e9;
5531 # We increment skip because caller(1) is the first level *back* from
5532 # the current one. Add $skip to the count of frames so we have a
5533 # simple stop criterion, counting from $skip to $count+$skip.
5537 # These variables are used to capture output from caller();
5538 my ($p, $file, $line, $sub, $h, $context);
5540 my ($e, $r, @a, @sub, $args);
5542 # XXX Okay... why'd we do that?
5543 my $nothard = not $frame & 8;
5546 # Do not want to trace this.
5547 my $otrace = $trace;
5550 # Start out at the skip count.
5551 # If we haven't reached the number of frames requested, and caller() is
5552 # still returning something, stay in the loop. (If we pass the requested
5553 # number of stack frames, or we run out - caller() returns nothing - we
5555 # Up the stack frame index to go back one more level each time.
5559 and ($p,$file,$line,$sub,$h,$context,$e,$r) = caller($i);
5564 # Go through the arguments and save them for later.
5568 if (not defined $arg) {
5572 elsif ($nothard and tied $arg) {
5575 elsif ($nothard and $type = ref $arg) {
5576 push @a, "ref($type)";
5580 "$arg"; # Safe to stringify now - should not call f().
5582 # Backslash any single-quotes or backslashes.
5585 # Single-quote it unless it's a number or a colon-separated
5588 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
5590 # Turn high-bit characters into meta-whatever.
5591 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
5593 # Turn control characters into ^-whatever.
5594 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
5597 } ## end else [ if (not defined $arg)
5598 } ## end for $arg (@args)
5600 # If context is true, this is array (@)context.
5601 # If context is false, this is scalar ($) context.
5602 # If neither, context isn't defined. (This is apparently a 'can't
5604 $context = $context ? '@' : (defined $context ? "\$" : '.');
5606 # if the sub has args ($h true), make an anonymous array of the
5608 $args = $h ? [@a] : undef;
5610 # remove trailing newline-whitespace-semicolon-end of line sequence
5611 # from the eval text, if any.
5612 $e =~ s/\n\s*\;\s*\Z// if $e;
5614 # Escape backslashed single-quotes again if necessary.
5615 $e =~ s/([\\\'])/\\$1/g if $e;
5617 # if the require flag is true, the eval text is from a require.
5619 $sub = "require '$e'";
5621 # if it's false, the eval text is really from an eval.
5622 elsif (defined $r) {
5626 # If the sub is '(eval)', this is a block eval, meaning we don't
5627 # know what the eval'ed text actually was.
5628 elsif ($sub eq '(eval)') {
5629 $sub = "eval {...}";
5632 # Stick the collected information into @sub as an anonymous hash.
5636 context => $context,
5644 # Stop processing frames if the user hit control-C.
5646 } ## end for ($i = $skip ; $i < ...
5648 # Restore the trace value again.
5651 } ## end sub dump_trace
5655 C<action()> takes input provided as the argument to an add-action command,
5656 either pre- or post-, and makes sure it's a complete command. It doesn't do
5657 any fancy parsing; it just keeps reading input until it gets a string
5658 without a trailing backslash.
5665 while ($action =~ s/\\$//) {
5666 # We have a backslash on the end. Read more.
5668 } ## end while ($action =~ s/\\$//)
5670 # Return the assembled action.
5676 This routine mostly just packages up a regular expression to be used
5677 to check that the thing it's being matched against has properly-matched
5680 Of note is the definition of the $balanced_brace_re global via ||=, which
5681 speeds things up by only creating the qr//'ed expression once; if it's
5682 already defined, we don't try to define it again. A speed hack.
5688 # I hate using globals!
5689 $balanced_brace_re ||= qr{
5692 (?> [^{}] + ) # Non-parens without backtracking
5694 (??{ $balanced_brace_re }) # Group with matching parens
5698 return $_[0] !~ m/$balanced_brace_re/;
5699 } ## end sub unbalanced
5703 C<gets()> is a primitive (very primitive) routine to read continuations.
5704 It was devised for reading continuations for actions.
5705 it just reads more input with X<C<readline()>> and returns it.
5710 &readline("cont: ");
5713 =head2 C<DB::system()> - handle calls to<system()> without messing up the debugger
5715 The C<system()> function assumes that it can just go ahead and use STDIN and
5716 STDOUT, but under the debugger, we want it to use the debugger's input and
5719 C<DB::system()> socks away the program's STDIN and STDOUT, and then substitutes
5720 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
5721 and then puts everything back again.
5726 # We save, change, then restore STDIN and STDOUT to avoid fork() since
5727 # some non-Unix systems can do system() but have problems with fork().
5728 open(SAVEIN,"<&STDIN") || &warn("Can't save STDIN");
5729 open(SAVEOUT,">&STDOUT") || &warn("Can't save STDOUT");
5730 open(STDIN,"<&IN") || &warn("Can't redirect STDIN");
5731 open(STDOUT,">&OUT") || &warn("Can't redirect STDOUT");
5733 # XXX: using csh or tcsh destroys sigint retvals!
5735 open(STDIN,"<&SAVEIN") || &warn("Can't restore STDIN");
5736 open(STDOUT,">&SAVEOUT") || &warn("Can't restore STDOUT");
5740 # most of the $? crud was coping with broken cshisms
5742 &warn("(Command exited ", ($? >> 8), ")\n");
5746 "(Command died of SIG#",
5748 (($? & 128) ? " -- core dumped" : ""),
5757 =head1 TTY MANAGEMENT
5759 The subs here do some of the terminal management for multiple debuggers.
5763 Top-level function called when we want to set up a new terminal for use
5766 If the C<noTTY> debugger option was set, we'll either use the terminal
5767 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
5768 to find one. If we're a forked debugger, we call C<resetterm> to try to
5769 get a whole new terminal if we can.
5771 In either case, we set up the terminal next. If the C<ReadLine> option was
5772 true, we'll get a C<Term::ReadLine> object for the current terminal and save
5773 the appropriate attributes. We then
5778 # Load Term::Readline, but quietly; don't debug it and don't trace it.
5781 eval { require Term::ReadLine } or die $@;
5783 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
5786 my ($i, $o) = split $tty, /,/;
5787 $o = $i unless defined $o;
5788 open(IN, "<$i") or die "Cannot open TTY `$i' for read: $!";
5789 open(OUT, ">$o") or die "Cannot open TTY `$o' for write: $!";
5792 my $sel = select($OUT);
5797 # We don't have a TTY - try to find one via Term::Rendezvous.
5799 eval "require Term::Rendezvous;" or die;
5800 # See if we have anything to pass to Term::Rendezvous.
5801 # Use /tmp/perldbtty$$ if not.
5802 my $rv = $ENV{PERLDB_NOTTY} || ".perldbtty$$";
5804 # Rendezvous and get the filehandles.
5805 my $term_rv = new Term::Rendezvous $rv;
5807 $OUT = $term_rv->OUT;
5808 } ## end else [ if ($tty)
5809 } ## end if ($notty)
5812 # We're a daughter debugger. Try to fork off another TTY.
5813 if ($term_pid eq '-1') { # In a TTY with another debugger
5817 # If we shouldn't use Term::ReadLine, don't.
5819 $term = new Term::ReadLine::Stub 'perldb', $IN, $OUT;
5822 # We're using Term::ReadLine. Get all the attributes for this terminal.
5824 $term = new Term::ReadLine 'perldb', $IN, $OUT;
5826 $rl_attribs = $term->Attribs;
5827 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
5828 if defined $rl_attribs->{basic_word_break_characters}
5829 and index($rl_attribs->{basic_word_break_characters}, ":") == -1;
5830 $rl_attribs->{special_prefixes} = '$@&%';
5831 $rl_attribs->{completer_word_break_characters} .= '$@&%';
5832 $rl_attribs->{completion_function} = \&db_complete;
5833 } ## end else [ if (!$rl)
5835 # Set up the LINEINFO filehandle.
5836 $LINEINFO = $OUT unless defined $LINEINFO;
5837 $lineinfo = $console unless defined $lineinfo;
5841 if ($term->Features->{setHistory} and "@hist" ne "?") {
5842 $term->SetHistory(@hist);
5845 # XXX Ornaments are turned on unconditionally, which is not
5846 # always a good thing.
5847 ornaments($ornaments) if defined $ornaments;
5849 } ## end sub setterm
5851 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
5853 When the process being debugged forks, or the process invokes a command
5854 via C<system()> which starts a new debugger, we need to be able to get a new
5855 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
5856 fight over the terminal, and you can never quite be sure who's going to get the
5857 input you're typing.
5859 C<get_fork_TTY> is a glob-aliased function which calls the real function that
5860 is tasked with doing all the necessary operating system mojo to get a new
5861 TTY (and probably another window) and to direct the new debugger to read and
5864 The debugger provides C<get_fork_TTY> functions which work for X Windows and
5865 OS/2. Other systems are not supported. You are encouraged to write
5866 C<get_fork_TTY> functions which work for I<your> platform and contribute them.
5868 =head3 C<xterm_get_fork_TTY>
5870 This function provides the C<get_fork_TTY> function for X windows. If a
5871 program running under the debugger forks, a new <xterm> window is opened and
5872 the subsidiary debugger is directed there.
5874 The C<open()> call is of particular note here. We have the new C<xterm>
5875 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
5876 command (which prints the device name of the TTY we'll want to use for input
5877 and output to STDOUT, then C<sleep> for a very long time, routing this output
5878 to file number 3. This way we can simply read from the <XT> filehandle (which
5879 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
5881 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
5886 sub xterm_get_fork_TTY {
5887 (my $name = $0) =~ s,^.*[/\\],,s;
5889 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
5892 # Get the output from 'tty' and clean it up a little.
5896 $pidprompt = ''; # Shown anyway in titlebar
5898 # There's our new TTY.
5900 } ## end sub xterm_get_fork_TTY
5902 =head3 C<os2_get_fork_TTY>
5904 XXX It behooves an OS/2 expert to write the necessary documentation for this!
5908 # This example function resets $IN, $OUT itself
5909 sub os2_get_fork_TTY {
5910 local $^F = 40; # XXXX Fixme!
5912 my ($in1, $out1, $in2, $out2);
5914 # Having -d in PERL5OPT would lead to a disaster...
5915 local $ENV{PERL5OPT} = $ENV{PERL5OPT} if $ENV{PERL5OPT};
5916 $ENV{PERL5OPT} =~ s/(?:^|(?<=\s))-d\b// if $ENV{PERL5OPT};
5917 $ENV{PERL5OPT} =~ s/(?:^|(?<=\s))-d\B/-/ if $ENV{PERL5OPT};
5918 print $OUT "Making kid PERL5OPT->`$ENV{PERL5OPT}'.\n" if $ENV{PERL5OPT};
5919 local $ENV{PERL5LIB} = $ENV{PERL5LIB} ? $ENV{PERL5LIB} : $ENV{PERLLIB};
5920 $ENV{PERL5LIB} = '' unless defined $ENV{PERL5LIB};
5921 $ENV{PERL5LIB} = join ';', @ini_INC, split /;/, $ENV{PERL5LIB};
5922 (my $name = $0) =~ s,^.*[/\\],,s;
5927 and pipe $in2, $out2
5929 # system P_SESSION will fail if there is another process
5930 # in the same session with a "dependent" asynchronous child session.
5932 $rl, fileno $in1, fileno $out2,
5933 "Daughter Perl debugger $pids $name"
5936 ($kpid = CORE::system 4, $^X, '-we',
5937 <<'ES', @args) >= 0 # P_SESSION
5938 END {sleep 5 unless $loaded}
5939 BEGIN {open STDIN, '</dev/con' or warn "reopen stdin: $!"}
5942 my ($rl, $in) = (shift, shift); # Read from $in and pass through
5944 system P_NOWAIT, $^X, '-we', <<EOS or die "Cannot start a grandkid";
5945 open IN, '<&=$in' or die "open <&=$in: \$!";
5946 \$| = 1; print while sysread IN, \$_, 1<<16;
5950 open OUT, ">&=$out" or die "Cannot open &=$out for writing: $!";
5952 require Term::ReadKey if $rl;
5953 Term::ReadKey::ReadMode(4) if $rl; # Nodelay on kbd. Pipe is automatically nodelay...
5954 print while sysread STDIN, $_, 1<<($rl ? 16 : 0);
5956 or warn "system P_SESSION: $!, $^E" and 0
5962 $pidprompt = ''; # Shown anyway in titlebar
5963 reset_IN_OUT($in2, $out1);
5965 return ''; # Indicate that reset_IN_OUT is called
5966 } ## end if (pipe $in1, $out1 and...
5968 } ## end sub os2_get_fork_TTY
5970 =head2 C<create_IN_OUT($flags)>
5972 Create a new pair of filehandles, pointing to a new TTY. If impossible,
5973 try to diagnose why.
5979 =item * 1 - Don't know how to create a new TTY.
5981 =item * 2 - Debugger has forked, but we can't get a new TTY.
5983 =item * 4 - standard debugger startup is happening.
5989 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
5991 # If we know how to get a new TTY, do it! $in will have
5992 # the TTY name if get_fork_TTY works.
5993 my $in = &get_fork_TTY if defined &get_fork_TTY;
5995 # It used to be that
5996 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
5997 if (not defined $in) {
6000 # We don't know how.
6001 print_help(<<EOP) if $why == 1;
6002 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
6006 print_help(<<EOP) if $why == 2;
6007 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
6008 This may be an asynchronous session, so the parent debugger may be active.
6011 # Note that both debuggers are fighting over the same input.
6012 print_help(<<EOP) if $why != 4;
6013 Since two debuggers fight for the same TTY, input is severely entangled.
6017 I know how to switch the output to a different window in xterms
6018 and OS/2 consoles only. For a manual switch, put the name of the created I<TTY>
6019 in B<\$DB::fork_TTY>, or define a function B<DB::get_fork_TTY()> returning this.
6021 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
6022 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
6025 } ## end if (not defined $in)
6031 $console = ''; # Indicate no need to open-from-the-console
6034 } ## end sub create_IN_OUT
6038 Handles rejiggering the prompt when we've forked off a new debugger.
6040 If the new debugger happened because of a C<system()> that invoked a
6041 program under the debugger, the arrow between the old pid and the new
6042 in the prompt has I<two> dashes instead of one.
6044 We take the current list of pids and add this one to the end. If there
6045 isn't any list yet, we make one up out of the initial pid associated with
6046 the terminal and our new pid, sticking an arrow (either one-dashed or
6047 two dashed) in between them.
6049 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
6050 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
6055 sub resetterm { # We forked, so we need a different TTY
6057 # Needs to be passed to create_IN_OUT() as well.
6060 # resetterm(2): got in here because of a system() starting a debugger.
6061 # resetterm(1): just forked.
6062 my $systemed = $in > 1 ? '-' : '';
6064 # If there's already a list of pids, add this to the end.
6066 $pids =~ s/\]/$systemed->$$]/;
6069 # No pid list. Time to make one.
6071 $pids = "[$term_pid->$$]";
6074 # The prompt we're going to be using for this debugger.
6077 # We now 0wnz this terminal.
6080 # Just return if we're not supposed to try to create a new TTY.
6081 return unless $CreateTTY & $in;
6083 # Try to create a new IN/OUT pair.
6085 } ## end sub resetterm
6089 First, we handle stuff in the typeahead buffer. If there is any, we shift off
6090 the next line, print a message saying we got it, add it to the terminal
6091 history (if possible), and return it.
6093 If there's nothing in the typeahead buffer, check the command filehandle stack.
6094 If there are any filehandles there, read from the last one, and return the line
6095 if we got one. If not, we pop the filehandle off and close it, and try the
6096 next one up the stack.
6098 If we've emptied the filehandle stack, we check to see if we've got a socket
6099 open, and we read that and return it if we do. If we don't, we just call the
6100 core C<readline()> and return its value.
6106 # Localize to prevent it from being smashed in the program being debugged.
6109 # Pull a line out of the typeahead if there's stuff there.
6111 # How many lines left.
6112 my $left = @typeahead;
6114 # Get the next line.
6115 my $got = shift @typeahead;
6117 # Print a message saying we got input from the typeahead.
6119 print $OUT "auto(-$left)", shift, $got, "\n";
6121 # Add it to the terminal history (if possible).
6122 $term->AddHistory($got)
6124 and defined $term->Features->{addHistory};
6126 } ## end if (@typeahead)
6128 # We really need to read some input. Turn off entry/exit trace and
6129 # return value printing.
6133 # If there are stacked filehandles to read from ...
6135 # Read from the last one in the stack.
6136 my $line = CORE::readline($cmdfhs[-1]);
6137 # If we got a line ...
6139 ? (print $OUT ">> $line" and return $line)
6140 : close pop @cmdfhs;
6141 } ## end while (@cmdfhs)
6143 # Nothing on the filehandle stack. Socket?
6144 if (ref $OUT and UNIVERSAL::isa($OUT, 'IO::Socket::INET')) {
6145 # Send anyting we have to send.
6146 $OUT->write(join('', @_));
6148 # Receive anything there is to receive.
6150 $IN->recv( $stuff, 2048 ); # XXX: what's wrong with sysread?
6154 } ## end if (ref $OUT and UNIVERSAL::isa...
6156 # No socket. Just read from the terminal.
6158 $term->readline(@_);
6160 } ## end sub readline
6162 =head1 OPTIONS SUPPORT ROUTINES
6164 These routines handle listing and setting option values.
6166 =head2 C<dump_option> - list the current value of an option setting
6168 This routine uses C<option_val> to look up the value for an option.
6169 It cleans up escaped single-quotes and then displays the option and
6175 my ($opt, $val)= @_;
6176 $val = option_val($opt,'N/A');
6177 $val =~ s/([\\\'])/\\$1/g;
6178 printf $OUT "%20s = '%s'\n", $opt, $val;
6179 } ## end sub dump_option
6182 sub options2remember {
6183 foreach my $k (@RememberOnROptions) {
6184 $option{$k}=option_val($k, 'N/A');
6189 =head2 C<option_val> - find the current value of an option
6191 This can't just be a simple hash lookup because of the indirect way that
6192 the option values are stored. Some are retrieved by calling a subroutine,
6193 some are just variables.
6195 You must supply a default value to be used in case the option isn't set.
6200 my ($opt, $default) = @_;
6203 # Does this option exist, and is it a variable?
6204 # If so, retrieve the value via the value in %optionVars.
6205 if (defined $optionVars{$opt}
6206 and defined ${ $optionVars{$opt} }) {
6207 $val = ${ $optionVars{$opt} };
6210 # Does this option exist, and it's a subroutine?
6211 # If so, call the subroutine via the ref in %optionAction
6212 # and capture the value.
6213 elsif (defined $optionAction{$opt}
6214 and defined &{$optionAction{$opt}}) {
6215 $val = &{$optionAction{$opt}}();
6218 # If there's an action or variable for the supplied option,
6219 # but no value was set, use the default.
6220 elsif (defined $optionAction{$opt} and not defined $option{$opt}
6221 or defined $optionVars{$opt} and not defined ${$optionVars{$opt}})
6226 # Otherwise, do the simple hash lookup.
6228 $val = $option{$opt};
6231 # If the value isn't defined, use the default.
6232 # Then return whatever the value is.
6233 $val = $default unless defined $val;
6235 } ## end sub option_val
6237 =head2 C<parse_options>
6239 Handles the parsing and execution of option setting/displaying commands.
6241 An option entered by itself is assumed to be 'set me to 1' (the default value)
6242 if the option is a boolean one. If not, the user is prompted to enter a valid
6243 value or to query the current value (via 'option? ').
6245 If 'option=value' is entered, we try to extract a quoted string from the
6246 value (if it is quoted). If it's not, we just use the whole value as-is.
6248 We load any modules required to service this option, and then we set it: if
6249 it just gets stuck in a variable, we do that; if there's a subroutine to
6250 handle setting the option, we call that.
6252 Finally, if we're running in interactive mode, we display the effect of the
6253 user's command back to the terminal, skipping this if we're setting things
6254 during initialization.
6262 # These options need a value. Don't allow them to be clobbered by accident.
6263 my %opt_needs_val = map { ($_ => 1) } qw{
6264 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
6265 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
6271 # Clean off excess leading whitespace.
6274 # Options are always all word characters, followed by a non-word
6276 s/^(\w+)(\W?)// or print($OUT "Invalid option `$_'\n"), last;
6277 my ($opt,$sep) = ($1,$2);
6281 # '?' as separator means query, but must have whitespace after it.
6283 print($OUT "Option query `$opt?' followed by non-space `$_'\n"), last
6286 #&dump_option($opt);
6287 } ## end if ("?" eq $sep)
6289 # Separator is whitespace (or just a carriage return).
6290 # They're going for a default, which we assume is 1.
6291 elsif ($sep !~ /\S/) {
6293 $val = "1"; # this is an evil default; make 'em set it!
6296 # Separator is =. Trying to set a value.
6297 elsif ($sep eq "=") {
6298 # If quoted, extract a quoted string.
6299 if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
6301 ($val = $2) =~ s/\\([$quote\\])/$1/g;
6304 # Not quoted. Use the whole thing. Warn about 'option='.
6308 print OUT qq(Option better cleared using $opt=""\n)
6310 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
6312 } ## end elsif ($sep eq "=")
6314 # "Quoted" with [], <>, or {}.
6315 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
6316 my ($end) = "\\" . substr( ")]>}$sep", index("([<{",$sep), 1 ); #}
6317 s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
6318 or print($OUT "Unclosed option value `$opt$sep$_'\n"), last;
6319 ($val = $1) =~ s/\\([\\$end])/$1/g;
6320 } ## end else [ if ("?" eq $sep)
6323 my $matches = grep( /^\Q$opt/ && ($option = $_), @options )
6324 || grep( /^\Q$opt/i && ($option = $_), @options );
6326 print($OUT "Unknown option `$opt'\n"), next unless $matches;
6327 print($OUT "Ambiguous option `$opt'\n"), next if $matches > 1;
6329 # Exclude non-booleans from getting set to 1 by default.
6330 if ($opt_needs_val{$option} && $val_defaulted) {
6331 my $cmd = ($CommandSet eq '580') ? 'o' : 'O';
6332 print $OUT "Option `$opt' is non-boolean. Use `$cmd $option=VAL' to set, `$cmd $option?' to query\n";
6334 } ## end if ($opt_needs_val{$option...
6336 # Save the option value.
6337 $option{$option} = $val if defined $val;
6339 # Load any module that this option requires.
6343 require '$optionRequire{$option}';
6345 } || die # XXX: shouldn't happen
6346 if defined $optionRequire{$option} &&
6350 # Stick it in the proper variable if it goes in a variable.
6351 ${$optionVars{$option}} = $val
6352 if defined $optionVars{$option} &&
6355 # Call the appropriate sub if it gets set via sub.
6356 &{$optionAction{$option}} ($val)
6357 if defined $optionAction{$option} &&
6358 defined &{$optionAction{$option}} &&
6361 # Not initialization - echo the value we set it to.
6362 dump_option($option) unless $OUT eq \*STDERR;
6363 } ## end while (length)
6364 } ## end sub parse_options
6366 =head1 RESTART SUPPORT
6368 These routines are used to store (and restore) lists of items in environment
6369 variables during a restart.
6373 Set_list packages up items to be stored in a set of environment variables
6374 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
6375 the values). Values outside the standard ASCII charset are stored by encoding
6376 then as hexadecimal values.
6381 my ($stem, @list) = @_;
6384 # VAR_n: how many we have. Scalar assignment gets the number of items.
6385 $ENV{"${stem}_n"} = @list;
6387 # Grab each item in the list, escape the backslashes, encode the non-ASCII
6388 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
6389 for $i (0 .. $#list) {
6391 $val =~ s/\\/\\\\/g;
6392 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
6393 $ENV{"${stem}_$i"} = $val;
6394 } ## end for $i (0 .. $#list)
6395 } ## end sub set_list
6399 Reverse the set_list operation: grab VAR_n to see how many we should be getting
6400 back, and then pull VAR_0, VAR_1. etc. back out.
6407 my $n = delete $ENV{"${stem}_n"};
6409 for $i (0 .. $n - 1) {
6410 $val = delete $ENV{"${stem}_$i"};
6411 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
6415 } ## end sub get_list
6417 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
6421 The C<catch()> subroutine is the essence of fast and low-impact. We simply
6422 set an already-existing global scalar variable to a constant value. This
6423 avoids allocating any memory possibly in the middle of something that will
6424 get all confused if we do.
6430 return; # Put nothing on the stack - malloc/free land!
6435 C<warn> emits a warning, by joining together its arguments and printing
6436 them, with couple of fillips.
6438 If the composited message I<doesn't> end with a newline, we automatically
6439 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
6440 to be set to the filehandle to be used to output warnings; it makes no
6441 assumptions about what filehandles are available.
6446 my ($msg) = join ("", @_);
6447 $msg .= ": $!\n" unless $msg =~ /\n$/;
6452 =head1 INITIALIZATION TTY SUPPORT
6454 =head2 C<reset_IN_OUT>
6456 This routine handles restoring the debugger's input and output filehandles
6457 after we've tried and failed to move them elsewhere. In addition, it assigns
6458 the debugger's output filehandle to $LINEINFO if it was already open there.
6463 my $switch_li = $LINEINFO eq $OUT;
6465 # If there's a term and it's able to get a new tty, try to get one.
6466 if ($term and $term->Features->{newTTY}) {
6467 ($IN, $OUT) = (shift, shift);
6468 $term->newTTY($IN, $OUT);
6471 # This term can't get a new tty now. Better luck later.
6473 &warn("Too late to set IN/OUT filehandles, enabled on next `R'!\n");
6476 # Set the filehndles up as they were.
6478 ($IN, $OUT) = (shift, shift);
6481 # Unbuffer the output filehandle.
6482 my $o = select $OUT;
6486 # Point LINEINFO to the same output filehandle if it was there before.
6487 $LINEINFO = $OUT if $switch_li;
6488 } ## end sub reset_IN_OUT
6490 =head1 OPTION SUPPORT ROUTINES
6492 The following routines are used to process some of the more complicated
6497 Sets the input and output filehandles to the specified files or pipes.
6498 If the terminal supports switching, we go ahead and do it. If not, and
6499 there's already a terminal in place, we save the information to take effect
6502 If there's no terminal yet (for instance, during debugger initialization),
6503 we go ahead and set C<$console> and C<$tty> to the file indicated.
6508 if (@_ and $term and $term->Features->{newTTY}) {
6509 # This terminal supports switching to a new TTY.
6510 # Can be a list of two files, or on string containing both names,
6512 # XXX Should this perhaps be an assignment from @_?
6513 my ($in, $out) = shift;
6515 # Split list apart if supplied.
6516 ($in, $out) = split /,/, $in, 2;
6519 # Use the same file for both input and output.
6523 # Open file onto the debugger's filehandles, if you can.
6524 open IN, $in or die "cannot open `$in' for read: $!";
6525 open OUT, ">$out" or die "cannot open `$out' for write: $!";
6527 # Swap to the new filehandles.
6528 reset_IN_OUT(\*IN,\*OUT);
6530 # Save the setting for later.
6532 } ## end if (@_ and $term and $term...
6534 # Terminal doesn't support new TTY, or doesn't support readline.
6535 # Can't do it now, try restarting.
6536 &warn("Too late to set TTY, enabled on next `R'!\n") if $term and @_;
6538 # Useful if done through PERLDB_OPTS:
6539 # Useful if done through PERLDB_OPTS:
6540 $console = $tty = shift if @_;
6542 # Return whatever the TTY is.
6548 Sets the C<$notty> global, controlling whether or not the debugger tries to
6549 get a terminal to read from. If called after a terminal is already in place,
6550 we save the value to use it if we're restarted.
6556 &warn("Too late to set noTTY, enabled on next `R'!\n") if @_;
6558 $notty = shift if @_;
6564 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
6565 (essentially, no C<readline> processing on this "terminal"). Otherwise, we
6566 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
6567 the value in case a restart is done so we can change it then.
6573 &warn("Too late to set ReadLine, enabled on next `R'!\n") if @_;
6577 } ## end sub ReadLine
6579 =head2 C<RemotePort>
6581 Sets the port that the debugger will try to connect to when starting up.
6582 If the terminal's already been set up, we can't do it, but we remember the
6583 setting in case the user does a restart.
6589 &warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
6591 $remoteport = shift if @_;
6593 } ## end sub RemotePort
6597 Checks with the terminal to see if C<Tk> is running, and returns true or
6598 false. Returns false if the current terminal doesn't support C<readline>.
6603 if (${ $term->Features }{tkRunning}) {
6604 return $term->tkRunning(@_);
6608 print $OUT "tkRunning not supported by current ReadLine package.\n";
6611 } ## end sub tkRunning
6615 Sets nonstop mode. If a terminal's already been set up, it's too late; the
6616 debugger remembers the setting in case you restart, though.
6622 &warn("Too late to set up NonStop mode, enabled on next `R'!\n")
6625 $runnonstop = shift if @_;
6627 } ## end sub NonStop
6632 &warn("Some flag changes could not take effect until next 'R'!\n") if @_;
6634 $^P = parse_DollarCaretP_flags(shift) if @_;
6635 expand_DollarCaretP_flags($^P)
6638 sub OnlyAssertions {
6640 &warn("Too late to set up OnlyAssertions mode, enabled on next 'R'!\n") if @_;
6643 unless (defined $ini_assertion) {
6645 &warn("Current Perl interpreter doesn't support assertions");
6650 unless ($ini_assertion) {
6651 print "Assertions will be active on next 'R'!\n";
6654 $^P&= ~$DollarCaretP_flags{PERLDBf_SUB};
6655 $^P|=$DollarCaretP_flags{PERLDBf_ASSERTION};
6658 $^P|=$DollarCaretP_flags{PERLDBf_SUB};
6661 !($^P & $DollarCaretP_flags{PERLDBf_SUB}) || 0;
6666 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
6674 $pager="|".$pager unless $pager =~ /^(\+?\>|\|)/;
6681 Sets the shell escape command, and generates a printable copy to be used
6688 # If we got an argument, meta-quote it, and add '\b' if it
6689 # ends in a word character.
6691 $sh = quotemeta shift;
6692 $sh .= "\\b" if $sh =~ /\w$/;
6695 # Generate the printable version for the help:
6696 $psh = $sh; # copy it
6697 $psh =~ s/\\b$//; # Take off trailing \b if any
6698 $psh =~ s/\\(.)/$1/g; # De-escape
6699 $psh; # return the printable version
6700 } ## end sub shellBang
6704 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
6705 was passed as the argument. (This means you can't override the terminal's
6711 if (defined $term) {
6712 # We don't want to show warning backtraces, but we do want die() ones.
6713 local ($warnLevel,$dieLevel) = (0, 1);
6715 # No ornaments if the terminal doesn't support them.
6716 return '' unless $term->Features->{ornaments};
6717 eval { $term->ornaments(@_) } || '';
6720 # Use what was passed in if we can't determine it ourselves.
6724 } ## end sub ornaments
6726 =head2 C<recallCommand>
6728 Sets the recall command, and builds a printable version which will appear in
6735 # If there is input, metaquote it. Add '\b' if it ends with a word
6738 $rc = quotemeta shift;
6739 $rc .= "\\b" if $rc =~ /\w$/;
6742 # Build it into a printable version.
6743 $prc = $rc; # Copy it
6744 $prc =~ s/\\b$//; # Remove trailing \b
6745 $prc =~ s/\\(.)/$1/g; # Remove escapes
6746 $prc; # Return the printable version
6747 } ## end sub recallCommand
6749 =head2 C<LineInfo> - where the line number information goes
6751 Called with no arguments, returns the file or pipe that line info should go to.
6753 Called with an argument (a file or a pipe), it opens that onto the
6754 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
6755 file or pipe again to the caller.
6760 return $lineinfo unless @_;
6763 # If this is a valid "thing to be opened for output", tack a
6764 # '>' onto the front.
6765 my $stream = ($lineinfo =~ /^(\+?\>|\|)/) ? $lineinfo : ">$lineinfo";
6767 # If this is a pipe, the stream points to a slave editor.
6768 $slave_editor = ($stream =~ /^\|/);
6770 # Open it up and unbuffer it.
6771 open(LINEINFO, "$stream") || &warn("Cannot open `$stream' for write");
6772 $LINEINFO = \*LINEINFO;
6773 my $save = select($LINEINFO);
6777 # Hand the file or pipe back again.
6779 } ## end sub LineInfo
6781 =head1 COMMAND SUPPORT ROUTINES
6783 These subroutines provide functionality for various commands.
6785 =head2 C<list_modules>
6787 For the C<M> command: list modules loaded and their versions.
6788 Essentially just runs through the keys in %INC, picks up the
6789 $VERSION package globals from each package, gets the file name, and formats the
6790 information for output.
6795 sub list_modules { # versions
6798 # keys are the "as-loaded" name, values are the fully-qualified path
6799 # to the file itself.
6805 s/^Term::ReadLine::readline$/readline/;
6806 # If the package has a $VERSION package global (as all good packages
6807 # should!) decode it and save as partial message.
6808 if (defined ${ $_ . '::VERSION' }) {
6809 $version{$file} = "${ $_ . '::VERSION' } from ";
6812 # Finish up the message with the file the package came from.
6813 $version{$file} .= $INC{$file};
6814 } ## end for (keys %INC)
6816 # Hey, dumpit() formats a hash nicely, so why not use it?
6817 dumpit($OUT,\%version);
6818 } ## end sub list_modules
6822 Sets up the monster string used to format and print the help.
6824 =head3 HELP MESSAGE FORMAT
6826 The help message is a peculiar format unto itself; it mixes C<pod> 'ornaments'
6827 (BE<lt>E<gt>, IE<gt>E<lt>) with tabs to come up with a format that's fairly
6828 easy to parse and portable, but which still allows the help to be a little
6829 nicer than just plain text.
6831 Essentially, you define the command name (usually marked up with BE<gt>E<lt>
6832 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
6833 need to continue the descriptive text to another line, start that line with
6834 just tabs and then enter the marked-up text.
6836 If you are modifying the help text, I<be careful>. The help-string parser is
6837 not very sophisticated, and if you don't follow these rules it will mangle the
6838 help beyond hope until you fix the string.
6844 # XXX: make sure there are tabs between the command and explanation,
6845 # or print_help will screw up your formatting if you have
6846 # eeevil ornaments enabled. This is an insane mess.
6849 Help is currently only available for the new 580 CommandSet,
6850 if you really want old behaviour, presumably you know what
6854 B<s> [I<expr>] Single step [in I<expr>].
6855 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
6856 <B<CR>> Repeat last B<n> or B<s> command.
6857 B<r> Return from current subroutine.
6858 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
6859 at the specified position.
6860 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
6861 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
6862 B<l> I<line> List single I<line>.
6863 B<l> I<subname> List first window of lines from subroutine.
6864 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
6865 B<l> List next window of lines.
6866 B<-> List previous window of lines.
6867 B<v> [I<line>] View window around I<line>.
6868 B<.> Return to the executed line.
6869 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
6870 I<filename> may be either the full name of the file, or a regular
6871 expression matching the full file name:
6872 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
6873 Evals (with saved bodies) are considered to be filenames:
6874 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
6875 (in the order of execution).
6876 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
6877 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
6878 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
6879 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
6880 B<t> Toggle trace mode.
6881 B<t> I<expr> Trace through execution of I<expr>.
6882 B<b> Sets breakpoint on current line)
6883 B<b> [I<line>] [I<condition>]
6884 Set breakpoint; I<line> defaults to the current execution line;
6885 I<condition> breaks if it evaluates to true, defaults to '1'.
6886 B<b> I<subname> [I<condition>]
6887 Set breakpoint at first line of subroutine.
6888 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
6889 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
6890 B<b> B<postpone> I<subname> [I<condition>]
6891 Set breakpoint at first line of subroutine after
6893 B<b> B<compile> I<subname>
6894 Stop after the subroutine is compiled.
6895 B<B> [I<line>] Delete the breakpoint for I<line>.
6896 B<B> I<*> Delete all breakpoints.
6897 B<a> [I<line>] I<command>
6898 Set an action to be done before the I<line> is executed;
6899 I<line> defaults to the current execution line.
6900 Sequence is: check for breakpoint/watchpoint, print line
6901 if necessary, do action, prompt user if necessary,
6904 B<A> [I<line>] Delete the action for I<line>.
6905 B<A> I<*> Delete all actions.
6906 B<w> I<expr> Add a global watch-expression.
6908 B<W> I<expr> Delete a global watch-expression.
6909 B<W> I<*> Delete all watch-expressions.
6910 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
6911 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
6912 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
6913 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
6914 B<x> I<expr> Evals expression in list context, dumps the result.
6915 B<m> I<expr> Evals expression in list context, prints methods callable
6916 on the first element of the result.
6917 B<m> I<class> Prints methods callable via the given class.
6918 B<M> Show versions of loaded modules.
6919 B<i> I<class> Prints nested parents of given class.
6920 B<y> [I<n> [I<vars>]] List lexical variables I<n> levels up from current sub
6922 B<<> ? List Perl commands to run before each prompt.
6923 B<<> I<expr> Define Perl command to run before each prompt.
6924 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
6925 B<< *> Delete the list of perl commands to run before each prompt.
6926 B<>> ? List Perl commands to run after each prompt.
6927 B<>> I<expr> Define Perl command to run after each prompt.
6928 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
6929 B<>>B< *> Delete the list of Perl commands to run after each prompt.
6930 B<{> I<db_command> Define debugger command to run before each prompt.
6931 B<{> ? List debugger commands to run before each prompt.
6932 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
6933 B<{ *> Delete the list of debugger commands to run before each prompt.
6934 B<$prc> I<number> Redo a previous command (default previous command).
6935 B<$prc> I<-number> Redo number'th-to-last command.
6936 B<$prc> I<pattern> Redo last command that started with I<pattern>.
6937 See 'B<O> I<recallCommand>' too.
6938 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
6943 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
6946 See 'B<O> I<shellBang>' too.
6947 B<source> I<file> Execute I<file> containing debugger commands (may nest).
6948 B<save> I<file> Save current debugger session (actual history) to I<file>.
6949 B<H> I<-number> Display last number commands (default all).
6950 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
6951 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
6952 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
6953 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
6954 I<command> Execute as a perl statement in current package.
6955 B<R> Pure-man-restart of debugger, some of debugger state
6956 and command-line options may be lost.
6957 Currently the following settings are preserved:
6958 history, breakpoints and actions, debugger B<O>ptions
6959 and the following command-line options: I<-w>, I<-I>, I<-e>.
6961 B<o> [I<opt>] ... Set boolean option to true
6962 B<o> [I<opt>B<?>] Query options
6963 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
6964 Set options. Use quotes in spaces in value.
6965 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
6966 I<pager> program for output of \"|cmd\";
6967 I<tkRunning> run Tk while prompting (with ReadLine);
6968 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
6969 I<inhibit_exit> Allows stepping off the end of the script.
6970 I<ImmediateStop> Debugger should stop as early as possible.
6971 I<RemotePort> Remote hostname:port for remote debugging
6972 The following options affect what happens with B<V>, B<X>, and B<x> commands:
6973 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
6974 I<compactDump>, I<veryCompact> change style of array and hash dump;
6975 I<globPrint> whether to print contents of globs;
6976 I<DumpDBFiles> dump arrays holding debugged files;
6977 I<DumpPackages> dump symbol tables of packages;
6978 I<DumpReused> dump contents of \"reused\" addresses;
6979 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
6980 I<bareStringify> Do not print the overload-stringified value;
6981 Other options include:
6982 I<PrintRet> affects printing of return value after B<r> command,
6983 I<frame> affects printing messages on subroutine entry/exit.
6984 I<AutoTrace> affects printing messages on possible breaking points.
6985 I<maxTraceLen> gives max length of evals/args listed in stack trace.
6986 I<ornaments> affects screen appearance of the command line.
6987 I<CreateTTY> bits control attempts to create a new TTY on events:
6988 1: on fork() 2: debugger is started inside debugger
6990 During startup options are initialized from \$ENV{PERLDB_OPTS}.
6991 You can put additional initialization options I<TTY>, I<noTTY>,
6992 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
6993 `B<R>' after you set them).
6995 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
6996 B<h> Summary of debugger commands.
6997 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
6998 B<h h> Long help for debugger commands
6999 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7000 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7001 Set B<\$DB::doccmd> to change viewer.
7003 Type `|h h' for a paged display if this was too hard to read.
7005 "; # Fix balance of vi % matching: }}}}
7007 # note: tabs in the following section are not-so-helpful
7008 $summary = <<"END_SUM";
7009 I<List/search source lines:> I<Control script execution:>
7010 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7011 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7012 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
7013 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7014 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7015 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
7016 I<Debugger controls:> B<L> List break/watch/actions
7017 B<o> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7018 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7019 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
7020 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7021 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
7022 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
7023 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
7024 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7025 B<q> or B<^D> Quit B<R> Attempt a restart
7026 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7027 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7028 B<p> I<expr> Print expression (uses script's current package).
7029 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7030 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7031 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
7032 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7033 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7035 # ')}}; # Fix balance of vi % matching
7037 # and this is really numb...
7040 B<s> [I<expr>] Single step [in I<expr>].
7041 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7042 <B<CR>> Repeat last B<n> or B<s> command.
7043 B<r> Return from current subroutine.
7044 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7045 at the specified position.
7046 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7047 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7048 B<l> I<line> List single I<line>.
7049 B<l> I<subname> List first window of lines from subroutine.
7050 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7051 B<l> List next window of lines.
7052 B<-> List previous window of lines.
7053 B<w> [I<line>] List window around I<line>.
7054 B<.> Return to the executed line.
7055 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7056 I<filename> may be either the full name of the file, or a regular
7057 expression matching the full file name:
7058 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7059 Evals (with saved bodies) are considered to be filenames:
7060 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7061 (in the order of execution).
7062 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7063 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7064 B<L> List all breakpoints and actions.
7065 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7066 B<t> Toggle trace mode.
7067 B<t> I<expr> Trace through execution of I<expr>.
7068 B<b> [I<line>] [I<condition>]
7069 Set breakpoint; I<line> defaults to the current execution line;
7070 I<condition> breaks if it evaluates to true, defaults to '1'.
7071 B<b> I<subname> [I<condition>]
7072 Set breakpoint at first line of subroutine.
7073 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7074 B<b> B<load> I<filename> Set breakpoint on `require'ing the given file.
7075 B<b> B<postpone> I<subname> [I<condition>]
7076 Set breakpoint at first line of subroutine after
7078 B<b> B<compile> I<subname>
7079 Stop after the subroutine is compiled.
7080 B<d> [I<line>] Delete the breakpoint for I<line>.
7081 B<D> Delete all breakpoints.
7082 B<a> [I<line>] I<command>
7083 Set an action to be done before the I<line> is executed;
7084 I<line> defaults to the current execution line.
7085 Sequence is: check for breakpoint/watchpoint, print line
7086 if necessary, do action, prompt user if necessary,
7088 B<a> [I<line>] Delete the action for I<line>.
7089 B<A> Delete all actions.
7090 B<W> I<expr> Add a global watch-expression.
7091 B<W> Delete all watch-expressions.
7092 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7093 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7094 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7095 B<x> I<expr> Evals expression in list context, dumps the result.
7096 B<m> I<expr> Evals expression in list context, prints methods callable
7097 on the first element of the result.
7098 B<m> I<class> Prints methods callable via the given class.
7100 B<<> ? List Perl commands to run before each prompt.
7101 B<<> I<expr> Define Perl command to run before each prompt.
7102 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7103 B<>> ? List Perl commands to run after each prompt.
7104 B<>> I<expr> Define Perl command to run after each prompt.
7105 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7106 B<{> I<db_command> Define debugger command to run before each prompt.
7107 B<{> ? List debugger commands to run before each prompt.
7108 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7109 B<$prc> I<number> Redo a previous command (default previous command).
7110 B<$prc> I<-number> Redo number'th-to-last command.
7111 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7112 See 'B<O> I<recallCommand>' too.
7113 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7118 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7121 See 'B<O> I<shellBang>' too.
7122 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7123 B<H> I<-number> Display last number commands (default all).
7124 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7125 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7126 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7127 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7128 I<command> Execute as a perl statement in current package.
7129 B<v> Show versions of loaded modules.
7130 B<R> Pure-man-restart of debugger, some of debugger state
7131 and command-line options may be lost.
7132 Currently the following settings are preserved:
7133 history, breakpoints and actions, debugger B<O>ptions
7134 and the following command-line options: I<-w>, I<-I>, I<-e>.
7136 B<O> [I<opt>] ... Set boolean option to true
7137 B<O> [I<opt>B<?>] Query options
7138 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7139 Set options. Use quotes in spaces in value.
7140 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7141 I<pager> program for output of \"|cmd\";
7142 I<tkRunning> run Tk while prompting (with ReadLine);
7143 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7144 I<inhibit_exit> Allows stepping off the end of the script.
7145 I<ImmediateStop> Debugger should stop as early as possible.
7146 I<RemotePort> Remote hostname:port for remote debugging
7147 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7148 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7149 I<compactDump>, I<veryCompact> change style of array and hash dump;
7150 I<globPrint> whether to print contents of globs;
7151 I<DumpDBFiles> dump arrays holding debugged files;
7152 I<DumpPackages> dump symbol tables of packages;
7153 I<DumpReused> dump contents of \"reused\" addresses;
7154 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7155 I<bareStringify> Do not print the overload-stringified value;
7156 Other options include:
7157 I<PrintRet> affects printing of return value after B<r> command,
7158 I<frame> affects printing messages on subroutine entry/exit.
7159 I<AutoTrace> affects printing messages on possible breaking points.
7160 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7161 I<ornaments> affects screen appearance of the command line.
7162 I<CreateTTY> bits control attempts to create a new TTY on events:
7163 1: on fork() 2: debugger is started inside debugger
7165 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7166 You can put additional initialization options I<TTY>, I<noTTY>,
7167 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7168 `B<R>' after you set them).
7170 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7171 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7172 B<h h> Summary of debugger commands.
7173 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7174 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7175 Set B<\$DB::doccmd> to change viewer.
7177 Type `|h' for a paged display if this was too hard to read.
7179 "; # Fix balance of vi % matching: }}}}
7181 # note: tabs in the following section are not-so-helpful
7182 $pre580_summary = <<"END_SUM";
7183 I<List/search source lines:> I<Control script execution:>
7184 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7185 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7186 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
7187 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7188 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7189 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
7190 I<Debugger controls:> B<L> List break/watch/actions
7191 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7192 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7193 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
7194 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7195 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
7196 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
7197 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7198 B<q> or B<^D> Quit B<R> Attempt a restart
7199 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7200 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7201 B<p> I<expr> Print expression (uses script's current package).
7202 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7203 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7204 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
7205 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7206 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7209 # ')}}; # Fix balance of vi % matching
7211 } ## end sub sethelp
7213 =head2 C<print_help()>
7215 Most of what C<print_help> does is just text formatting. It finds the
7216 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
7217 terminal control characters to simulate them (courtesy of
7218 <Term::ReadLine::TermCap>).
7225 # Restore proper alignment destroyed by eeevil I<> and B<>
7226 # ornaments: A pox on both their houses!
7228 # A help command will have everything up to and including
7229 # the first tab sequence padded into a field 16 (or if indented 20)
7230 # wide. If it's wider than that, an extra space will be added.
7232 ^ # only matters at start of line
7233 ( \040{4} | \t )* # some subcommands are indented
7234 ( < ? # so <CR> works
7235 [BI] < [^\t\n] + ) # find an eeevil ornament
7236 ( \t+ ) # original separation, discarded
7237 ( .* ) # this will now start (no earlier) than
7240 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
7241 my $clean = $command;
7242 $clean =~ s/[BI]<([^>]*)>/$1/g;
7244 # replace with this whole string:
7245 ($leadwhite ? " " x 4 : "")
7247 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
7252 s{ # handle bold ornaments
7253 B < ( [^>] + | > ) >
7255 $Term::ReadLine::TermCap::rl_term_set[2]
7257 . $Term::ReadLine::TermCap::rl_term_set[3]
7260 s{ # handle italic ornaments
7261 I < ( [^>] + | > ) >
7263 $Term::ReadLine::TermCap::rl_term_set[0]
7265 . $Term::ReadLine::TermCap::rl_term_set[1]
7270 } ## end sub print_help
7274 This routine does a lot of gyrations to be sure that the pager is C<less>.
7275 It checks for C<less> masquerading as C<more> and records the result in
7276 C<$ENV{LESS}> so we don't have to go through doing the stats again.
7282 # We already know if this is set.
7283 return if defined $ENV{LESS} && $ENV{LESS} =~ /r/;
7285 # Pager is less for sure.
7286 my $is_less = $pager =~ /\bless\b/;
7287 if ($pager =~ /\bmore\b/) {
7288 # Nope, set to more. See what's out there.
7289 my @st_more = stat('/usr/bin/more');
7290 my @st_less = stat('/usr/bin/less');
7292 # is it really less, pretending to be more?
7293 $is_less = @st_more && @st_less
7294 && $st_more[0] == $st_less[0]
7295 && $st_more[1] == $st_less[1];
7296 } ## end if ($pager =~ /\bmore\b/)
7298 # changes environment!
7299 # 'r' added so we don't do (slow) stats again.
7300 # changes environment!
7301 $ENV{LESS} .= 'r' if $is_less;
7302 } ## end sub fix_less
7304 =head1 DIE AND WARN MANAGEMENT
7308 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
7309 to debug a debugger problem.
7311 It does its best to report the error that occurred, and then forces the
7312 program, debugger, and everything to die.
7317 # No entry/exit messages.
7320 # No return value prints.
7323 # set the abort signal handling to the default (just terminate).
7324 $SIG{'ABRT'} = 'DEFAULT';
7326 # If we enter the signal handler recursively, kill myself with an
7327 # abort signal (so we just terminate).
7328 kill 'ABRT', $$ if $panic++;
7330 # If we can show detailed info, do so.
7331 if (defined &Carp::longmess) {
7332 # Don't recursively enter the warn handler, since we're carping.
7333 local $SIG{__WARN__} = '';
7335 # Skip two levels before reporting traceback: we're skipping
7336 # mydie and confess.
7337 local $Carp::CarpLevel = 2; # mydie + confess
7339 # Tell us all about it.
7340 &warn(Carp::longmess("Signal @_"));
7343 # No Carp. Tell us about the signal as best we can.
7346 print $DB::OUT "Got signal @_\n";
7351 } ## end sub diesignal
7355 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
7356 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
7362 # No entry/exit trace.
7365 # No return value printing.
7368 # Turn off warn and die handling to prevent recursive entries to this
7370 local $SIG{__WARN__} = '';
7371 local $SIG{__DIE__} = '';
7373 # Load Carp if we can. If $^S is false (current thing being compiled isn't
7374 # done yet), we may not be able to do a require.
7375 eval { require Carp }
7376 if defined $^S; # If error/warning during compilation,
7377 # require may be broken.
7379 # Use the core warn() unless Carp loaded OK.
7381 "\nCannot print stack trace, load with -MCarp option to see stack"),
7383 unless defined &Carp::longmess;
7385 # Save the current values of $single and $trace, and then turn them off.
7386 my ($mysingle, $mytrace) = ($single, $trace);
7390 # We can call Carp::longmess without its being "debugged" (which we
7391 # don't want - we just want to use it!). Capture this for later.
7392 my $mess = Carp::longmess(@_);
7394 # Restore $single and $trace to their original values.
7395 ($single,$trace) = ($mysingle,$mytrace);
7397 # Use the debugger's own special way of printing warnings to print
7398 # the stack trace message.
7404 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
7405 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
7406 single stepping and tracing during the call to C<Carp::longmess> to avoid
7407 debugging it - we just want to use it.
7409 If C<dieLevel> is zero, we let the program being debugged handle the
7410 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
7411 the debugger takes over all exception handling, printing a backtrace and
7412 displaying the exception via its C<dbwarn()> routine.
7420 local $SIG{__DIE__} = '';
7421 local $SIG{__WARN__} = '';
7422 my $i = 0; my $ineval = 0; my $sub;
7423 if ($dieLevel > 2) {
7424 local $SIG{__WARN__} = \&dbwarn;
7425 &warn(@_); # Yell no matter what
7428 if ($dieLevel < 2) {
7429 die @_ if $^S; # in eval propagate
7432 # The code used to check $^S to see if compiliation of the current thing
7433 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
7434 # No need to check $^S, eval is much more robust nowadays
7435 eval { require Carp }; #if defined $^S;# If error/warning during compilation,
7436 # require may be broken.
7438 die(@_, "\nCannot print stack trace, load with -MCarp option to see stack")
7439 unless defined &Carp::longmess;
7441 # We do not want to debug this chunk (automatic disabling works
7442 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
7443 # get the stack trace from Carp::longmess (if possible), restore $signal
7444 # and $trace, and then die with the stack trace.
7445 my ($mysingle, $mytrace) = ($single, $trace);
7451 package Carp; # Do not include us in the list
7452 eval { $mess = Carp::longmess(@_); };
7454 ($single, $trace) = ($mysingle, $mytrace);
7458 =head2 C<warnlevel()>
7460 Set the C<$DB::warnLevel> variable that stores the value of the
7461 C<warnLevel> option. Calling C<warnLevel()> with a positive value
7462 results in the debugger taking over all warning handlers. Setting
7463 C<warnLevel> to zero leaves any warning handlers set up by the program
7464 being debugged in place.
7470 $prevwarn = $SIG{__WARN__} unless $warnLevel;
7473 $SIG{__WARN__} = \&DB::dbwarn;
7476 $SIG{__WARN__} = $prevwarn;
7480 } ## end sub warnLevel
7484 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
7485 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
7486 zero lets you use your own C<die()> handler.
7493 $prevdie = $SIG{__DIE__} unless $dieLevel;
7496 # Always set it to dbdie() for non-zero values.
7497 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
7499 # No longer exists, so don't try to use it.
7500 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
7502 # If we've finished initialization, mention that stack dumps
7503 # are enabled, If dieLevel is 1, we won't stack dump if we die
7505 print $OUT "Stack dump during die enabled",
7506 ($dieLevel == 1 ? " outside of evals" : ""), ".\n"
7509 # XXX This is probably obsolete, given that diehard() is gone.
7510 print $OUT "Dump printed too.\n" if $dieLevel > 2;
7511 } ## end if ($dieLevel)
7513 # Put the old one back if there was one.
7515 $SIG{__DIE__} = $prevdie;
7516 print $OUT "Default die handler restored.\n";
7520 } ## end sub dieLevel
7522 =head2 C<signalLevel>
7524 Number three in a series: set C<signalLevel> to zero to keep your own
7525 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
7526 takes over and handles them with C<DB::diesignal()>.
7532 $prevsegv = $SIG{SEGV} unless $signalLevel;
7533 $prevbus = $SIG{BUS} unless $signalLevel;
7534 $signalLevel = shift;
7536 $SIG{SEGV} = \&DB::diesignal;
7537 $SIG{BUS} = \&DB::diesignal;
7540 $SIG{SEGV} = $prevsegv;
7541 $SIG{BUS} = $prevbus;
7545 } ## end sub signalLevel
7547 =head1 SUBROUTINE DECODING SUPPORT
7549 These subroutines are used during the C<x> and C<X> commands to try to
7550 produce as much information as possible about a code reference. They use
7551 L<Devel::Peek> to try to find the glob in which this code reference lives
7552 (if it does) - this allows us to actually code references which correspond
7553 to named subroutines (including those aliased via glob assignment).
7555 =head2 C<CvGV_name()>
7557 Wrapper for X<CvGV_name_or_bust>; tries to get the name of a reference
7558 via that routine. If this fails, return the reference again (when the
7559 reference is stringified, it'll come out as "SOMETHING(0X...)").
7565 my $name = CvGV_name_or_bust($in);
7566 defined $name ? $name : $in;
7569 =head2 C<CvGV_name_or_bust> I<coderef>
7571 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
7572 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
7573 find a glob for this ref.
7575 Returns "I<package>::I<glob name>" if the code ref is found in a glob.
7579 sub CvGV_name_or_bust {
7581 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
7582 return unless ref $in;
7583 $in = \&$in; # Hard reference...
7584 eval { require Devel::Peek; 1 } or return;
7585 my $gv = Devel::Peek::CvGV($in) or return;
7586 *$gv{PACKAGE} . '::' . *$gv{NAME};
7587 } ## end sub CvGV_name_or_bust
7591 A utility routine used in various places; finds the file where a subroutine
7592 was defined, and returns that filename and a line-number range.
7594 Tries to use X<@sub> first; if it can't find it there, it tries building a
7595 reference to the subroutine and uses X<CvGV_name_or_bust> to locate it,
7596 loading it into X<@sub> as a side effect (XXX I think). If it can't find it
7597 this way, it brute-force searches X<%sub>, checking for identical references.
7604 return unless defined &$subr;
7605 my $name = CvGV_name_or_bust($subr);
7607 $data = $sub{$name} if defined $name;
7608 return $data if defined $data;
7611 $subr = \&$subr; # Hard reference
7614 $s = $_, last if $subr eq \&$_;
7618 } ## end sub find_sub
7622 A subroutine that uses the utility function X<methods_via> to find all the
7623 methods in the class corresponding to the current reference and in
7630 # Figure out the class - either this is the class or it's a reference
7631 # to something blessed into that class.
7633 $class = ref $class if ref $class;
7638 # Show the methods that this class has.
7639 methods_via($class, '', 1);
7640 methods_via('UNIVERSAL', 'UNIVERSAL', 0);
7641 } ## end sub methods
7643 =head2 C<methods_via($class, $prefix, $crawl_upward)>
7645 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
7646 all the parent class methods. C<$class> is the name of the next class to
7647 try; C<$prefix> is the message prefix, which gets built up as we go up the
7648 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
7649 higher in the C<@ISA> tree, 0 if we should stop.
7654 # If we've processed this class already, just quit.
7656 return if $packs{$class}++;
7658 # This is a package that is contributing the methods we're about to print.
7660 my $prepend = $prefix ? "via $prefix: " : '';
7664 # Keep if this is a defined subroutine in this class.
7665 grep {defined &{${"${class}::"}{$_}}}
7666 # Extract from all the symbols in this class.
7667 sort keys %{"${class}::"}
7669 # If we printed this already, skip it.
7670 next if $seen{ $name }++;
7672 # Print the new method name.
7675 print $DB::OUT "$prepend$name\n";
7676 } ## end for $name (grep { defined...
7678 # If the $crawl_upward argument is false, just quit here.
7679 return unless shift; # Recurse?
7681 # $crawl_upward true: keep going up the tree.
7682 # Find all the classes this one is a subclass of.
7683 for $name (@{"${class}::ISA"}) {
7684 # Set up the new prefix.
7685 $prepend = $prefix ? $prefix . " -> $name" : $name;
7686 # Crawl up the tree and keep trying to crawl up.
7687 methods_via($name, $prepend, 1);
7689 } ## end sub methods_via
7691 =head2 C<setman> - figure out which command to use to show documentation
7693 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
7698 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|MacOS|NetWare)\z/s
7699 ? "man" # O Happy Day!
7700 : "perldoc"; # Alas, poor unfortunates
7703 =head2 C<runman> - run the appropriate command to show documentation
7705 Accepts a man page name; runs the appropriate command to display it (set up
7706 during debugger initialization). Uses C<DB::system> to avoid mucking up the
7707 program's STDIN and STDOUT.
7715 &system("$doccmd $doccmd");
7719 # this way user can override, like with $doccmd="man -Mwhatever"
7720 # or even just "man " to disable the path check.
7721 unless ($doccmd eq 'man') {
7722 &system("$doccmd $page");
7726 $page = 'perl' if lc($page) eq 'help';
7729 my $man1dir = $Config::Config{'man1dir'};
7730 my $man3dir = $Config::Config{'man3dir'};
7731 for ($man1dir, $man3dir) { s#/[^/]*\z## if /\S/ }
7733 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
7734 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
7735 chop $manpath if $manpath;
7737 # harmless if missing, I figure
7738 my $oldpath = $ENV{MANPATH};
7739 $ENV{MANPATH} = $manpath if $manpath;
7740 my $nopathopt = $^O =~ /dunno what goes here/;
7745 # I just *know* there are men without -M
7746 (($manpath && !$nopathopt) ? ("-M", $manpath) : ()),
7751 unless ($page =~ /^perl\w/) {
7753 grep { $page eq $_ }
7755 5004delta 5005delta amiga api apio book boot bot call compile
7756 cygwin data dbmfilter debug debguts delta diag doc dos dsc embed
7757 faq faq1 faq2 faq3 faq4 faq5 faq6 faq7 faq8 faq9 filter fork
7758 form func guts hack hist hpux intern ipc lexwarn locale lol mod
7759 modinstall modlib number obj op opentut os2 os390 pod port
7760 ref reftut run sec style sub syn thrtut tie toc todo toot tootc
7761 trap unicode var vms win32 xs xstut
7766 CORE::system($doccmd,
7767 (($manpath && !$nopathopt) ? ("-M", $manpath) : ()),
7769 } ## end if (grep { $page eq $_...
7770 } ## end unless ($page =~ /^perl\w/)
7771 } ## end if (CORE::system($doccmd...
7772 if (defined $oldpath) {
7773 $ENV{MANPATH} = $manpath;
7776 delete $ENV{MANPATH};
7780 #use Carp; # This did break, left for debugging
7782 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
7784 Because of the way the debugger interface to the Perl core is designed, any
7785 debugger package globals that C<DB::sub()> requires have to be defined before
7786 any subroutines can be called. These are defined in the second C<BEGIN> block.
7788 This block sets things up so that (basically) the world is sane
7789 before the debugger starts executing. We set up various variables that the
7790 debugger has to have set up before the Perl core starts running:
7794 =item * The debugger's own filehandles (copies of STD and STDOUT for now).
7796 =item * Characters for shell escapes, the recall command, and the history command.
7798 =item * The maximum recursion depth.
7800 =item * The size of a C<w> command's window.
7802 =item * The before-this-line context to be printed in a C<v> (view a window around this line) command.
7804 =item * The fact that we're not in a sub at all right now.
7806 =item * The default SIGINT handler for the debugger.
7808 =item * The appropriate value of the flag in C<$^D> that says the debugger is running
7810 =item * The current debugger recursion level
7812 =item * The list of postponed (XXX define) items and the C<$single> stack
7814 =item * That we want no return values and no subroutine entry/exit trace.
7820 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
7822 BEGIN { # This does not compile, alas.
7823 $IN = \*STDIN; # For bugs before DB::OUT has been opened
7824 $OUT = \*STDERR; # For errors before DB::OUT has been opened
7826 # Define characters used by command parsing.
7827 $sh = '!'; # Shell escape (does not work)
7828 $rc = ','; # Recall command (does not work)
7829 @hist = ('?'); # Show history (does not work)
7830 @truehist=(); # Can be saved for replay (per session)
7832 # This defines the point at which you get the 'deep recursion'
7833 # warning. It MUST be defined or the debugger will not load.
7836 # Number of lines around the current one that are shown in the
7840 # How much before-the-current-line context the 'v' command should
7841 # use in calculating the start of the window it will display.
7844 # We're not in any sub yet, but we need this to be a defined value.
7847 # Set up the debugger's interrupt handler. It simply sets a flag
7848 # ($signal) that DB::DB() will check before each command is executed.
7849 $SIG{INT} = \&DB::catch;
7851 # The following lines supposedly, if uncommented, allow the debugger to
7852 # debug itself. Perhaps we can try that someday.
7853 # This may be enabled to debug debugger:
7854 #$warnLevel = 1 unless defined $warnLevel;
7855 #$dieLevel = 1 unless defined $dieLevel;
7856 #$signalLevel = 1 unless defined $signalLevel;
7858 # This is the flag that says "a debugger is running, please call
7859 # DB::DB and DB::sub". We will turn it on forcibly before we try to
7860 # execute anything in the user's context, because we always want to
7862 $db_stop = 0; # Compiler warning
7865 # This variable records how many levels we're nested in debugging. Used
7866 # Used in the debugger prompt, and in determining whether it's all over or
7868 $level = 0; # Level of recursive debugging
7870 # "Triggers bug (?) in perl if we postpone this until runtime."
7871 # XXX No details on this yet, or whether we should fix the bug instead
7872 # of work around it. Stay tuned.
7873 @postponed = @stack = (0);
7875 # Used to track the current stack depth using the auto-stacked-variable
7877 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
7879 # Don't print return values on exiting a subroutine.
7882 # No extry/exit tracing.
7887 BEGIN { $^W = $ini_warn; } # Switch warnings back
7889 =head1 READLINE SUPPORT - COMPLETION FUNCTION
7893 C<readline> support - adds command completion to basic C<readline>.
7895 Returns a list of possible completions to C<readline> when invoked. C<readline>
7896 will print the longest common substring following the text already entered.
7898 If there is only a single possible completion, C<readline> will use it in full.
7900 This code uses C<map> and C<grep> heavily to create lists of possible
7901 completion. Think LISP in this section.
7907 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
7908 # $text is the text to be completed.
7909 # $line is the incoming line typed by the user.
7910 # $start is the start of the text to be completed in the incoming line.
7911 my ($text, $line, $start) = @_;
7913 # Save the initial text.
7914 # The search pattern is current package, ::, extract the next qualifier
7915 # Prefix and pack are set to undef.
7916 my ($itext, $search, $prefix, $pack) =
7917 ($text, "^\Q${'package'}::\E([^:]+)\$");
7919 =head3 C<b postpone|compile>
7923 =item * Find all the subroutines that might match in this package
7925 =item * Add "postpone", "load", and "compile" as possibles (we may be completing the keyword itself
7927 =item * Include all the rest of the subs that are known
7929 =item * C<grep> out the ones that match the text we have so far
7931 =item * Return this as the list of possible completions
7937 return sort grep /^\Q$text/, (keys %sub),
7938 qw(postpone load compile), # subroutines
7939 (map { /$search/ ? ($1) : () } keys %sub)
7940 if (substr $line, 0, $start) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
7944 Get all the possible files from @INC as it currently stands and
7945 select the ones that match the text so far.
7949 return sort grep /^\Q$text/, values %INC # files
7950 if (substr $line, 0, $start) =~ /^\|*b\s+load\s+$/;
7952 =head3 C<V> (list variable) and C<m> (list modules)
7954 There are two entry points for these commands:
7956 =head4 Unqualified package names
7958 Get the top-level packages and grab everything that matches the text
7959 so far. For each match, recursively complete the partial packages to
7960 get all possible matching packages. Return this sorted list.
7964 return sort map {($_, db_complete($_ . "::", "V ", 2))}
7965 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : ()} keys %:: # top-packages
7966 if (substr $line, 0, $start) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
7968 =head4 Qualified package names
7970 Take a partially-qualified package and find all subpackages for it
7971 by getting all the subpackages for the package so far, matching all
7972 the subpackages against the text, and discarding all of them which
7973 start with 'main::'. Return this list.
7977 return sort map { ($_, db_complete($_ . "::", "V ", 2))}
7978 grep !/^main::/, grep /^\Q$text/,
7979 map { /^(.*)::$/ ? ($prefix . "::$1") : () } keys %{ $prefix . '::' }
7980 if (substr $line, 0, $start) =~ /^\|*[Vm]\s+$/
7981 and $text =~ /^(.*[^:])::?(\w*)$/
7984 =head3 C<f> - switch files
7986 Here, we want to get a fully-qualified filename for the C<f> command.
7991 =item 1. The original source file itself
7993 =item 2. A file from C<@INC>
7995 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
8001 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
8002 # We might possibly want to switch to an eval (which has a "filename"
8003 # like '(eval 9)'), so we may need to clean up the completion text
8004 # before proceeding.
8005 $prefix = length($1) - length($text);
8010 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
8011 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
8012 out of C<%main::>, add the initial source file, and extract the ones that
8013 match the completion text so far.
8018 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, (keys %main::),
8020 } ## end if ($line =~ /^\|*f\s+(.*)/)
8022 =head3 Subroutine name completion
8024 We look through all of the defined subs (the keys of C<%sub>) and
8025 return both all the possible matches to the subroutine name plus
8026 all the matches qualified to the current package.
8030 if ((substr $text, 0, 1) eq '&') { # subroutines
8031 $text = substr $text, 1;
8033 return sort map "$prefix$_", grep /^\Q$text/, (keys %sub),
8035 map { /$search/ ? ($1) : () }
8038 } ## end if ((substr $text, 0, ...
8040 =head3 Scalar, array, and hash completion: partially qualified package
8042 Much like the above, except we have to do a little more cleanup:
8046 if ($text =~ /^[\$@%](.*)::(.*)/) { # symbols in a package
8052 =item * Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
8056 $pack = ($1 eq 'main' ? '' : $1) . '::';
8060 =item * Figure out the prefix vs. what needs completing.
8064 $prefix = (substr $text, 0, 1) . $1 . '::';
8069 =item * Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
8073 my @out = map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
8078 =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.
8082 if (@out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext) {
8083 return db_complete($out[0], $line, $start);
8086 # Return the list of possibles.
8089 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
8095 =head3 Symbol completion: current package or package C<main>.
8100 if ($text =~ /^[\$@%]/) { # symbols (in $package + packages in main)
8106 =item * If it's C<main>, delete main to just get C<::> leading.
8110 $pack = ($package eq 'main' ? '' : $package) . '::';
8114 =item * We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
8118 $prefix = substr $text, 0, 1;
8119 $text = substr $text, 1;
8123 =item * If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
8127 my @out = map "$prefix$_", grep /^\Q$text/,
8128 (grep /^_?[a-zA-Z]/, keys %$pack),
8129 ( $pack eq '::' ? () : (grep /::$/, keys %::) ) ;
8131 =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.
8137 if (@out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext) {
8138 return db_complete($out[0], $line, $start);
8141 # Return the list of possibles.
8143 } ## end if ($text =~ /^[\$@%]/)
8147 We use C<option_val()> to look up the current value of the option. If there's
8148 only a single value, we complete the command in such a way that it is a
8149 complete command for setting the option in question. If there are multiple
8150 possible values, we generate a command consisting of the option plus a trailing
8151 question mark, which, if executed, will list the current value of the option.
8156 if ((substr $line, 0, $start) =~ /^\|*O\b.*\s$/) { # Options after a space
8157 # We look for the text to be matched in the list of possible options,
8158 # and fetch the current value.
8159 my @out = grep /^\Q$text/, @options;
8160 my $val = option_val($out[0], undef);
8162 # Set up a 'query option's value' command.
8164 if (not defined $val or $val =~ /[\n\r]/) {
8165 # There's really nothing else we can do.
8168 # We have a value. Create a proper option-setting command.
8169 elsif ($val =~ /\s/) {
8170 # XXX This may be an extraneous variable.
8173 # We'll want to quote the string (because of the embedded
8174 # whtespace), but we want to make sure we don't end up with
8175 # mismatched quote characters. We try several possibilities.
8176 foreach $l (split //, qq/\"\'\#\|/) {
8177 # If we didn't find this quote character in the value,
8178 # quote it using this quote character.
8179 $out = "$l$val$l ", last if (index $val, $l) == -1;
8181 } ## end elsif ($val =~ /\s/)
8183 # Don't need any quotes.
8188 # If there were multiple possible values, return '? ', which
8189 # makes the command into a query command. If there was just one,
8190 # have readline append that.
8191 $rl_attribs->{completer_terminator_character} =
8192 (@out == 1 ? $out : '? ');
8194 # Return list of possibilities.
8196 } ## end if ((substr $line, 0, ...
8198 =head3 Filename completion
8200 For entering filenames. We simply call C<readline>'s C<filename_list()>
8201 method with the completion text to get the possible completions.
8205 return $term->filename_list($text); # filenames
8207 } ## end sub db_complete
8209 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
8211 Functions that possibly ought to be somewhere else.
8221 print $OUT "Use `q' to quit or `R' to restart. `h q' for details.\n"
8226 If we have $ini_pids, save it in the environment; else remove it from the
8227 environment. Used by the C<R> (restart) command.
8232 if (defined($ini_pids)) {
8233 $ENV{PERLDB_PIDS} = $ini_pids;
8236 delete($ENV{PERLDB_PIDS});
8238 } ## end sub clean_ENV
8240 # PERLDBf_... flag names from perl.h
8241 our (%DollarCaretP_flags, %DollarCaretP_flags_r);
8243 %DollarCaretP_flags =
8244 ( PERLDBf_SUB => 0x01, # Debug sub enter/exit
8245 PERLDBf_LINE => 0x02, # Keep line #
8246 PERLDBf_NOOPT => 0x04, # Switch off optimizations
8247 PERLDBf_INTER => 0x08, # Preserve more data
8248 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
8249 PERLDBf_SINGLE => 0x20, # Start with single-step on
8250 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
8251 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
8252 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
8253 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
8254 PERLDBf_ASSERTION => 0x400, # Debug assertion subs enter/exit
8255 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO, _ASSERTION
8258 %DollarCaretP_flags_r=reverse %DollarCaretP_flags;
8261 sub parse_DollarCaretP_flags {
8266 foreach my $f (split /\s*\|\s*/, $flags) {
8268 if ($f=~/^0x([[:xdigit:]]+)$/) {
8271 elsif ($f=~/^(\d+)$/) {
8274 elsif ($f=~/^DEFAULT$/i) {
8275 $value=$DollarCaretP_flags{PERLDB_ALL};
8278 $f=~/^(?:PERLDBf_)?(.*)$/i;
8279 $value=$DollarCaretP_flags{'PERLDBf_'.uc($1)};
8280 unless (defined $value) {
8281 print $OUT ("Unrecognized \$^P flag '$f'!\n",
8282 "Acceptable flags are: ".
8283 join(', ', sort keys %DollarCaretP_flags),
8284 ", and hexadecimal and decimal numbers.\n");
8293 sub expand_DollarCaretP_flags {
8294 my $DollarCaretP=shift;
8295 my @bits= ( map { my $n=(1<<$_);
8296 ($DollarCaretP & $n)
8297 ? ($DollarCaretP_flags_r{$n}
8298 || sprintf('0x%x', $n))
8300 return @bits ? join('|', @bits) : 0;
8303 =head1 END PROCESSING - THE C<END> BLOCK
8305 Come here at the very end of processing. We want to go into a
8306 loop where we allow the user to enter commands and interact with the
8307 debugger, but we don't want anything else to execute.
8309 First we set the C<$finished> variable, so that some commands that
8310 shouldn't be run after the end of program quit working.
8312 We then figure out whether we're truly done (as in the user entered a C<q>
8313 command, or we finished execution while running nonstop). If we aren't,
8314 we set C<$single> to 1 (causing the debugger to get control again).
8316 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...">
8317 message and returns control to the debugger. Repeat.
8319 When the user finally enters a C<q> command, C<$fall_off_end> is set to
8320 1 and the C<END> block simply exits with C<$single> set to 0 (don't
8321 break, run to completion.).
8326 $finished = 1 if $inhibit_exit; # So that some keys may be disabled.
8327 $fall_off_end = 1 unless $inhibit_exit;
8329 # Do not stop in at_exit() and destructors on exit:
8330 $DB::single = !$fall_off_end && !$runnonstop;
8331 DB::fake::at_exit() unless $fall_off_end or $runnonstop;
8334 =head1 PRE-5.8 COMMANDS
8336 Some of the commands changed function quite a bit in the 5.8 command
8337 realignment, so much so that the old code had to be replaced completely.
8338 Because we wanted to retain the option of being able to go back to the
8339 former command set, we moved the old code off to this section.
8341 There's an awful lot of duplicated code here. We've duplicated the
8342 comments to keep things clear.
8346 Does nothing. Used to 'turn off' commands.
8350 sub cmd_pre580_null {
8355 =head2 Old C<a> command.
8357 This version added actions if you supplied them, and deleted them
8366 # Argument supplied. Add the action.
8367 if ($cmd =~ /^(\d*)\s*(.*)/) {
8369 # If the line isn't there, use the current line.
8373 # If there is an action ...
8376 # ... but the line isn't breakable, skip it.
8377 if ($dbline[$i] == 0) {
8378 print $OUT "Line $i may not have an action.\n";
8381 # ... and the line is breakable:
8382 # Mark that there's an action in this file.
8383 $had_breakpoints{$filename} |= 2;
8385 # Delete any current action.
8386 $dbline{$i} =~ s/\0[^\0]*//;
8388 # Add the new action, continuing the line as needed.
8389 $dbline{$i} .= "\0" . action($j);
8391 } ## end if (length $j)
8393 # No action supplied.
8395 # Delete the action.
8396 $dbline{$i} =~ s/\0[^\0]*//;
8397 delete $dbline{$i} if $dbline{$i} eq '';
8399 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
8400 } ## end sub cmd_pre580_a
8402 =head2 Old C<b> command
8414 if ($cmd =~ /^load\b\s*(.*)/) {
8420 # b compile|postpone <some sub> [<condition>]
8421 # The interpreter actually traps this one for us; we just put the
8422 # necessary condition in the %postponed hash.
8423 elsif ($cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/) {
8424 # Capture the condition if there is one. Make it true if none.
8425 my $cond = length $3 ? $3 : '1';
8427 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
8428 # if it was 'compile'.
8429 my ($subname, $break) = ($2, $1 eq 'postpone');
8431 # De-Perl4-ify the name - ' separators to ::.
8432 $subname =~ s/\'/::/g;
8434 # Qualify it into the current package unless it's already qualified.
8435 $subname = "${'package'}::" . $subname
8436 unless $subname =~ /::/;
8438 # Add main if it starts with ::.
8439 $subname = "main" . $subname if substr($subname,0,2) eq "::";
8441 # Save the break type for this sub.
8442 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
8443 } ## end elsif ($cmd =~ ...
8445 # b <sub name> [<condition>]
8446 elsif ($cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/) {
8448 my $cond = length $2 ? $2 : '1';
8449 &cmd_b_sub($subname, $cond);
8452 # b <line> [<condition>].
8453 elsif ($cmd =~ /^(\d*)\s*(.*)/) {
8454 my $i = $1 || $dbline;
8455 my $cond = length $2 ? $2 : '1';
8456 &cmd_b_line($i, $cond);
8458 } ## end sub cmd_pre580_b
8460 =head2 Old C<D> command.
8462 Delete all breakpoints unconditionally.
8469 if ($cmd =~ /^\s*$/) {
8470 print $OUT "Deleting all breakpoints...\n";
8472 # %had_breakpoints lists every file that had at least one
8475 for $file (keys %had_breakpoints) {
8476 # Switch to the desired file temporarily.
8477 local *dbline = $main::{'_<' . $file};
8482 # For all lines in this file ...
8483 for ($i = 1; $i <= $max ; $i++) {
8484 # If there's a breakpoint or action on this line ...
8485 if (defined $dbline{$i}) {
8486 # ... remove the breakpoint.
8487 $dbline{$i} =~ s/^[^\0]+//;
8488 if ($dbline{$i} =~ s/^\0?$//) {
8489 # Remove the entry altogether if no action is there.
8492 } ## end if (defined $dbline{$i...
8493 } ## end for ($i = 1 ; $i <= $max...
8495 # If, after we turn off the "there were breakpoints in this file"
8496 # bit, the entry in %had_breakpoints for this file is zero,
8497 # we should remove this file from the hash.
8498 if (not $had_breakpoints{$file} &= ~1) {
8499 delete $had_breakpoints{$file};
8501 } ## end for $file (keys %had_breakpoints)
8503 # Kill off all the other breakpoints that are waiting for files that
8504 # haven't been loaded yet.
8506 undef %postponed_file;
8507 undef %break_on_load;
8508 } ## end if ($cmd =~ /^\s*$/)
8509 } ## end sub cmd_pre580_D
8511 =head2 Old C<h> command
8513 Print help. Defaults to printing the long-form help; the 5.8 version
8514 prints the summary by default.
8522 # Print the *right* help, long format.
8523 if ($cmd =~ /^\s*$/) {
8524 print_help($pre580_help);
8527 # 'h h' - explicitly-requested summary.
8528 elsif ($cmd =~ /^h\s*/) {
8529 print_help($pre580_summary);
8532 # Find and print a command's help.
8533 elsif ($cmd =~ /^h\s+(\S.*)$/) {
8534 my $asked = $1; # for proper errmsg
8535 my $qasked = quotemeta($asked); # for searching
8536 # XXX: finds CR but not <CR>
8537 if ($pre580_help =~ /^
8539 (?:[IB]<) # Optional markup
8540 $qasked # The command name
8545 ( # The command help:
8547 (?:[IB]<) # Optional markup
8548 $qasked # The command name
8549 ([\s\S]*?) # Lines starting with tabs
8552 (?!\s)/mgx) # Line not starting with space
8553 # (Next command's help)
8557 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
8561 print_help("B<$asked> is not a debugger command.\n");
8563 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
8564 } ## end sub cmd_pre580_h
8566 =head2 Old C<W> command
8568 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
8576 # Delete all watch expressions.
8578 # No watching is going on.
8580 # Kill all the watch expressions and values.
8581 @to_watch = @old_watch = ();
8584 # Add a watch expression.
8585 elsif ($cmd =~ /^(.*)/s) {
8586 # add it to the list to be watched.
8589 # Get the current value of the expression.
8590 # Doesn't handle expressions returning list values!
8593 $val = (defined $val) ? "'$val'" : 'undef';
8596 push @old_watch, $val;
8598 # We're watching stuff.
8601 } ## end elsif ($cmd =~ /^(.*)/s)
8602 } ## end sub cmd_pre580_W
8604 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
8606 The debugger used to have a bunch of nearly-identical code to handle
8607 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
8608 C<cmd_prepost> unify all this into one set of code to handle the
8609 appropriate actions.
8611 =head2 C<cmd_pre590_prepost>
8613 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
8614 do something destructive. In pre 5.8 debuggers, the default action was to
8615 delete all the actions.
8619 sub cmd_pre590_prepost {
8621 my $line = shift || '*';
8624 return &cmd_prepost( $cmd, $line, $dbline );
8625 } ## end sub cmd_pre590_prepost
8627 =head2 C<cmd_prepost>
8629 Actually does all the handling foe C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
8630 Since the lists of actions are all held in arrays that are pointed to by
8631 references anyway, all we have to do is pick the right array reference and
8632 then use generic code to all, delete, or list actions.
8640 # No action supplied defaults to 'list'.
8641 my $line = shift || '?';
8644 # Make sure we have some array or another to address later.
8645 # This means that if ssome reason the tests fail, we won't be
8646 # trying to stash actions or delete them from the wrong place.
8649 # < - Perl code to run before prompt.
8650 if ( $cmd =~ /^\</o ) {
8651 $which = 'pre-perl';
8655 # > - Perl code to run after prompt.
8656 elsif ( $cmd =~ /^\>/o ) {
8657 $which = 'post-perl';
8661 # { - first check for properly-balanced braces.
8662 elsif ( $cmd =~ /^\{/o ) {
8663 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
8665 "$cmd is now a debugger command\nuse `;$cmd' if you mean Perl code\n";
8668 # Properly balanced. Pre-prompt debugger actions.
8670 $which = 'pre-debugger';
8673 } ## end elsif ( $cmd =~ /^\{/o )
8675 # Did we find something that makes sense?
8677 print $OUT "Confused by command: $cmd\n";
8683 if ( $line =~ /^\s*\?\s*$/o ) {
8685 # Nothing there. Complain.
8686 print $OUT "No $which actions.\n";
8689 # List the actions in the selected list.
8690 print $OUT "$which commands:\n";
8691 foreach my $action (@$aref) {
8692 print $OUT "\t$cmd -- $action\n";
8695 } ## end if ( $line =~ /^\s*\?\s*$/o)
8697 # Might be a delete.
8699 if ( length($cmd) == 1 ) {
8700 if ( $line =~ /^\s*\*\s*$/o ) {
8701 # It's a delete. Get rid of the old actions in the
8704 print $OUT "All $cmd actions cleared.\n";
8707 # Replace all the actions. (This is a <, >, or {).
8708 @$aref = action($line);
8710 } ## end if ( length($cmd) == 1)
8711 elsif ( length($cmd) == 2 ) {
8712 # Add the action to the line. (This is a <<, >>, or {{).
8713 push @$aref, action($line);
8716 # <<<, >>>>, {{{{{{ ... something not a command.
8718 "Confused by strange length of $which command($cmd)...\n";
8720 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
8722 } ## end sub cmd_prepost
8727 Contains the C<at_exit> routine that the debugger uses to issue the
8728 C<Debugged program terminated ...> message after the program completes. See
8729 the C<END> block documentation for more details.
8736 "Debugged program terminated. Use `q' to quit or `R' to restart.";
8739 package DB; # Do not trace this 1; below!