4 perl5db.pl - the perl debugger
8 perl -d your_Perl_script
12 C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when
13 you invoke a script with C<perl -d>. This documentation tries to outline the
14 structure and services provided by C<perl5db.pl>, and to describe how you
19 The debugger can look pretty forbidding to many Perl programmers. There are
20 a number of reasons for this, many stemming out of the debugger's history.
22 When the debugger was first written, Perl didn't have a lot of its nicer
23 features - no references, no lexical variables, no closures, no object-oriented
24 programming. So a lot of the things one would normally have done using such
25 features was done using global variables, globs and the C<local()> operator
28 Some of these have survived into the current debugger; a few of the more
29 interesting and still-useful idioms are noted in this section, along with notes
30 on the comments themselves.
32 =head2 Why not use more lexicals?
34 Experienced Perl programmers will note that the debugger code tends to use
35 mostly package globals rather than lexically-scoped variables. This is done
36 to allow a significant amount of control of the debugger from outside the
39 Unfortunately, though the variables are accessible, they're not well
40 documented, so it's generally been a decision that hasn't made a lot of
41 difference to most users. Where appropriate, comments have been added to
42 make variables more accessible and usable, with the understanding that these
43 I<are> debugger internals, and are therefore subject to change. Future
44 development should probably attempt to replace the globals with a well-defined
45 API, but for now, the variables are what we've got.
47 =head2 Automated variable stacking via C<local()>
49 As you may recall from reading C<perlfunc>, the C<local()> operator makes a
50 temporary copy of a variable in the current scope. When the scope ends, the
51 old copy is restored. This is often used in the debugger to handle the
52 automatic stacking of variables during recursive calls:
57 # Do some stuff, then ...
61 What happens is that on entry to the subroutine, C<$some_global> is localized,
62 then altered. When the subroutine returns, Perl automatically undoes the
63 localization, restoring the previous value. Voila, automatic stack management.
65 The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>,
66 which lets the debugger get control inside of C<eval>'ed code. The debugger
67 localizes a saved copy of C<$@> inside the subroutine, which allows it to
68 keep C<$@> safe until it C<DB::eval> returns, at which point the previous
69 value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep
70 track of C<$@> inside C<eval>s which C<eval> other C<eval's>.
72 In any case, watch for this pattern. It occurs fairly often.
76 This is used to cleverly reverse the sense of a logical test depending on
77 the value of an auxiliary variable. For instance, the debugger's C<S>
78 (search for subroutines by pattern) allows you to negate the pattern
81 # Find all non-'foo' subs:
84 Boolean algebra states that the truth table for XOR looks like this:
90 (! not present and no match) --> false, don't print
94 (! not present and matches) --> true, print
98 (! present and no match) --> true, print
102 (! present and matches) --> false, don't print
106 As you can see, the first pair applies when C<!> isn't supplied, and
107 the second pair applies when it is. The XOR simply allows us to
108 compact a more complicated if-then-elseif-else into a more elegant
109 (but perhaps overly clever) single test. After all, it needed this
112 =head2 FLAGS, FLAGS, FLAGS
114 There is a certain C programming legacy in the debugger. Some variables,
115 such as C<$single>, C<$trace>, and C<$frame>, have I<magical> values composed
116 of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces
117 of state to be stored independently in a single scalar.
123 is checking to see if the appropriate bit is on. Since each bit can be
124 "addressed" independently in this way, C<$scalar> is acting sort of like
125 an array of bits. Obviously, since the contents of C<$scalar> are just a
126 bit-pattern, we can save and restore it easily (it will just look like
129 The problem, is of course, that this tends to leave magic numbers scattered
130 all over your program whenever a bit is set, cleared, or checked. So why do
137 First, doing an arithmetical or bitwise operation on a scalar is
138 just about the fastest thing you can do in Perl: C<use constant> actually
139 creates a subroutine call, and array and hash lookups are much slower. Is
140 this over-optimization at the expense of readability? Possibly, but the
141 debugger accesses these variables a I<lot>. Any rewrite of the code will
142 probably have to benchmark alternate implementations and see which is the
143 best balance of readability and speed, and then document how it actually
148 Second, it's very easy to serialize a scalar number. This is done in
149 the restart code; the debugger state variables are saved in C<%ENV> and then
150 restored when the debugger is restarted. Having them be just numbers makes
155 Third, some of these variables are being shared with the Perl core
156 smack in the middle of the interpreter's execution loop. It's much faster for
157 a C program (like the interpreter) to check a bit in a scalar than to access
158 several different variables (or a Perl array).
162 =head2 What are those C<XXX> comments for?
164 Any comment containing C<XXX> means that the comment is either somewhat
165 speculative - it's not exactly clear what a given variable or chunk of
166 code is doing, or that it is incomplete - the basics may be clear, but the
167 subtleties are not completely documented.
169 Send in a patch if you can clear up, fill out, or clarify an C<XXX>.
171 =head1 DATA STRUCTURES MAINTAINED BY CORE
173 There are a number of special data structures provided to the debugger by
174 the Perl interpreter.
176 The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline>
177 via glob assignment) contains the text from C<$filename>, with each
178 element corresponding to a single line of C<$filename>. Additionally,
179 breakable lines will be dualvars with the numeric component being the
180 memory address of a COP node. Non-breakable lines are dualvar to 0.
182 The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
183 assignment) contains breakpoints and actions. The keys are line numbers;
184 you can set individual values, but not the whole hash. The Perl interpreter
185 uses this hash to determine where breakpoints have been set. Any true value is
186 considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>.
187 Values are magical in numeric context: 1 if the line is breakable, 0 if not.
189 The scalar C<${"_<$filename"}> simply contains the string C<<< _<$filename> >>>.
190 This is also the case for evaluated strings that contain subroutines, or
191 which are currently being executed. The $filename for C<eval>ed strings looks
194 =head1 DEBUGGER STARTUP
196 When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
197 non-interactive sessions, C<.perldb> for interactive ones) that can set a number
198 of options. In addition, this file may define a subroutine C<&afterinit>
199 that will be executed (in the debugger's context) after the debugger has
202 Next, it checks the C<PERLDB_OPTS> environment variable and treats its
203 contents as the argument of a C<o> command in the debugger.
205 =head2 STARTUP-ONLY OPTIONS
207 The following options can only be specified at startup.
208 To set them in your rcfile, add a call to
209 C<&parse_options("optionName=new_value")>.
215 the TTY to use for debugging i/o.
219 if set, goes in NonStop mode. On interrupt, if TTY is not set,
220 uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using
221 Term::Rendezvous. Current variant is to have the name of TTY in this
226 if false, a dummy ReadLine is used, so you can debug
227 ReadLine applications.
231 if true, no i/o is performed until interrupt.
235 file or pipe to print line number info to. If it is a
236 pipe, a short "emacs like" message is used.
240 host:port to connect to on remote host for remote debugging.
244 file to store session history to. There is no default and so no
245 history file is written unless this variable is explicitly set.
249 number of commands to store to the file specified in C<HistFile>.
256 &parse_options("NonStop=1 LineInfo=db.out");
257 sub afterinit { $trace = 1; }
259 The script will run without human intervention, putting trace
260 information into C<db.out>. (If you interrupt it, you had better
261 reset C<LineInfo> to something I<interactive>!)
263 =head1 INTERNALS DESCRIPTION
265 =head2 DEBUGGER INTERFACE VARIABLES
267 Perl supplies the values for C<%sub>. It effectively inserts
268 a C<&DB::DB();> in front of each place that can have a
269 breakpoint. At each subroutine call, it calls C<&DB::sub> with
270 C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
271 {require 'perl5db.pl'}> before the first line.
273 After each C<require>d file is compiled, but before it is executed, a
274 call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
275 is the expanded name of the C<require>d file (as found via C<%INC>).
277 =head3 IMPORTANT INTERNAL VARIABLES
281 Used to control when the debugger will attempt to acquire another TTY to be
286 =item * 1 - on C<fork()>
288 =item * 2 - debugger is started inside debugger
290 =item * 4 - on startup
296 The value -2 indicates that no return value should be printed.
297 Any other positive value causes C<DB::sub> to print return values.
301 The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
302 contents of C<@_> when C<DB::eval> is called.
306 Determines what messages (if any) will get printed when a subroutine (or eval)
307 is entered or exited.
311 =item * 0 - No enter/exit messages
313 =item * 1 - Print I<entering> messages on subroutine entry
315 =item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
317 =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.
319 =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.
321 =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.
325 To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
326 The debugger internally juggles the value of C<$frame> during execution to
327 protect external modules that the debugger uses from getting traced.
331 Tracks current debugger nesting level. Used to figure out how many
332 C<E<lt>E<gt>> pairs to surround the line number with when the debugger
333 outputs a prompt. Also used to help determine if the program has finished
334 during command parsing.
336 =head4 C<$onetimeDump>
338 Controls what (if anything) C<DB::eval()> will print after evaluating an
343 =item * C<undef> - don't print anything
345 =item * C<dump> - use C<dumpvar.pl> to display the value returned
347 =item * C<methods> - print the methods callable on the first item returned
351 =head4 C<$onetimeDumpDepth>
353 Controls how far down C<dumpvar.pl> will go before printing C<...> while
354 dumping a structure. Numeric. If C<undef>, print all levels.
358 Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
359 which is called before every statement, checks this and puts the user into
360 command mode if it finds C<$signal> set to a true value.
364 Controls behavior during single-stepping. Stacked in C<@stack> on entry to
365 each subroutine; popped again at the end of each subroutine.
369 =item * 0 - run continuously.
371 =item * 1 - single-step, go into subs. The C<s> command.
373 =item * 2 - single-step, don't go into subs. The C<n> command.
375 =item * 4 - print current sub depth (turned on to force this when C<too much
382 Controls the output of trace information.
386 =item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
388 =item * 2 - watch expressions are active
390 =item * 4 - user defined a C<watchfunction()> in C<afterinit()>
394 =head4 C<$slave_editor>
396 1 if C<LINEINFO> was directed to a pipe; 0 otherwise.
400 Stack of filehandles that C<DB::readline()> will read commands from.
401 Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
405 Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
406 supplied by the Perl interpreter to the debugger. Contains the source.
410 Previous values of watch expressions. First set when the expression is
411 entered; reset whenever the watch expression changes.
415 Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
416 so that the debugger can substitute safe values while it's running, and
417 restore them when it returns control.
421 Saves the current value of C<$single> on entry to a subroutine.
422 Manipulated by the C<c> command to turn off tracing in all subs above the
427 The 'watch' expressions: to be evaluated before each line is executed.
431 The typeahead buffer, used by C<DB::readline>.
435 Command aliases. Stored as character strings to be substituted for a command
438 =head4 C<%break_on_load>
440 Keys are file names, values are 1 (break when this file is loaded) or undef
441 (don't break when it is loaded).
445 Keys are line numbers, values are C<condition\0action>. If used in numeric
446 context, values are 0 if not breakable, 1 if breakable, no matter what is
447 in the actual hash entry.
449 =head4 C<%had_breakpoints>
451 Keys are file names; values are bitfields:
455 =item * 1 - file has a breakpoint in it.
457 =item * 2 - file has an action in it.
461 A zero or undefined value means this file has neither.
465 Stores the debugger options. These are character string values.
469 Saves breakpoints for code that hasn't been compiled yet.
470 Keys are subroutine names, values are:
474 =item * C<compile> - break when this sub is compiled
476 =item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
480 =head4 C<%postponed_file>
482 This hash keeps track of breakpoints that need to be set for files that have
483 not yet been compiled. Keys are filenames; values are references to hashes.
484 Each of these hashes is keyed by line number, and its values are breakpoint
485 definitions (C<condition\0action>).
487 =head1 DEBUGGER INITIALIZATION
489 The debugger's initialization actually jumps all over the place inside this
490 package. This is because there are several BEGIN blocks (which of course
491 execute immediately) spread through the code. Why is that?
493 The debugger needs to be able to change some things and set some things up
494 before the debugger code is compiled; most notably, the C<$deep> variable that
495 C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
496 debugger has to turn off warnings while the debugger code is compiled, but then
497 restore them to their original setting before the program being debugged begins
500 The first C<BEGIN> block simply turns off warnings by saving the current
501 setting of C<$^W> and then setting it to zero. The second one initializes
502 the debugger variables that are needed before the debugger begins executing.
503 The third one puts C<$^X> back to its former value.
505 We'll detail the second C<BEGIN> block later; just remember that if you need
506 to initialize something before the debugger starts really executing, that's
515 BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
519 $^V =~ /^v(\d+\.\d+)/;
520 feature->import(":$1");
523 # Debugger for Perl 5.00x; perl5db.pl patch level:
524 use vars qw($VERSION $header);
526 $VERSION = '1.39_05';
528 $header = "perl5db.pl version $VERSION";
530 =head1 DEBUGGER ROUTINES
534 This function replaces straight C<eval()> inside the debugger; it simplifies
535 the process of evaluating code in the user's context.
537 The code to be evaluated is passed via the package global variable
538 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
540 Before we do the C<eval()>, we preserve the current settings of C<$trace>,
541 C<$single>, C<$^D> and C<$usercontext>. The latter contains the
542 preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
543 user's current package, grabbed when C<DB::DB> got control. This causes the
544 proper context to be used when the eval is actually done. Afterward, we
545 restore C<$trace>, C<$single>, and C<$^D>.
547 Next we need to handle C<$@> without getting confused. We save C<$@> in a
548 local lexical, localize C<$saved[0]> (which is where C<save()> will put
549 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
550 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
551 considered sane by the debugger. If there was an C<eval()> error, we print
552 it on the debugger's output. If C<$onetimedump> is defined, we call
553 C<dumpit> if it's set to 'dump', or C<methods> if it's set to
554 'methods'. Setting it to something else causes the debugger to do the eval
555 but not print the result - handy if you want to do something else with it
556 (the "watch expressions" code does this to get the value of the watch
557 expression but not show it unless it matters).
559 In any case, we then return the list of output from C<eval> to the caller,
560 and unwinding restores the former version of C<$@> in C<@saved> as well
561 (the localization of C<$saved[0]> goes away at the end of this scope).
563 =head3 Parameters and variables influencing execution of DB::eval()
565 C<DB::eval> isn't parameterized in the standard way; this is to keep the
566 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
567 The variables listed below influence C<DB::eval()>'s execution directly.
571 =item C<$evalarg> - the thing to actually be eval'ed
573 =item C<$trace> - Current state of execution tracing
575 =item C<$single> - Current state of single-stepping
577 =item C<$onetimeDump> - what is to be displayed after the evaluation
579 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
583 The following variables are altered by C<DB::eval()> during its execution. They
584 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
588 =item C<@res> - used to capture output from actual C<eval>.
590 =item C<$otrace> - saved value of C<$trace>.
592 =item C<$osingle> - saved value of C<$single>.
594 =item C<$od> - saved value of C<$^D>.
596 =item C<$saved[0]> - saved value of C<$@>.
598 =item $\ - for output of C<$@> if there is an evaluation error.
602 =head3 The problem of lexicals
604 The context of C<DB::eval()> presents us with some problems. Obviously,
605 we want to be 'sandboxed' away from the debugger's internals when we do
606 the eval, but we need some way to control how punctuation variables and
607 debugger globals are used.
609 We can't use local, because the code inside C<DB::eval> can see localized
610 variables; and we can't use C<my> either for the same reason. The code
611 in this routine compromises and uses C<my>.
613 After this routine is over, we don't have user code executing in the debugger's
614 context, so we can use C<my> freely.
618 ############################################## Begin lexical danger zone
620 # 'my' variables used here could leak into (that is, be visible in)
621 # the context that the code being evaluated is executing in. This means that
622 # the code could modify the debugger's variables.
624 # Fiddling with the debugger's context could be Bad. We insulate things as
689 # Used to save @ARGV and extract any debugger-related flags.
692 # Used to prevent multiple entries to diesignal()
693 # (if for instance diesignal() itself dies)
696 # Used to prevent the debugger from running nonstop
700 sub _calc_usercontext {
703 # Cancel strict completely for the evaluated code, so the code
704 # the user evaluates won't be affected by it. (Shlomi Fish)
705 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @DB::saved;'
706 . "package $package;"; # this won't let them modify, alas
711 # 'my' would make it visible from user code
712 # but so does local! --tchrist
713 # Remember: this localizes @DB::res, not @main::res.
717 # Try to keep the user code from messing with us. Save these so that
718 # even if the eval'ed code changes them, we can put them back again.
719 # Needed because the user could refer directly to the debugger's
720 # package globals (and any 'my' variables in this containing scope)
721 # inside the eval(), and we want to try to stay safe.
722 local $otrace = $trace;
723 local $osingle = $single;
726 # Untaint the incoming eval() argument.
727 { ($evalarg) = $evalarg =~ /(.*)/s; }
729 # $usercontext built in DB::DB near the comment
730 # "set up the context for DB::eval ..."
731 # Evaluate and save any results.
732 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
734 # Restore those old values.
740 # Save the current value of $@, and preserve it in the debugger's copy
741 # of the saved precious globals.
744 # Since we're only saving $@, we only have to localize the array element
745 # that it will be stored in.
746 local $saved[0]; # Preserve the old value of $@
749 # Now see whether we need to report an error back to the user.
755 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
756 # are package globals.
757 elsif ($onetimeDump) {
758 if ( $onetimeDump eq 'dump' ) {
759 local $option{dumpDepth} = $onetimedumpDepth
760 if defined $onetimedumpDepth;
761 dumpit( $OUT, \@res );
763 elsif ( $onetimeDump eq 'methods' ) {
766 } ## end elsif ($onetimeDump)
770 ############################################## End lexical danger zone
772 # After this point it is safe to introduce lexicals.
773 # The code being debugged will be executing in its own context, and
774 # can't see the inside of the debugger.
776 # However, one should not overdo it: leave as much control from outside as
777 # possible. If you make something a lexical, it's not going to be addressable
778 # from outside the debugger even if you know its name.
780 # This file is automatically included if you do perl -d.
781 # It's probably not useful to include this yourself.
783 # Before venturing further into these twisty passages, it is
784 # wise to read the perldebguts man page or risk the ire of dragons.
786 # (It should be noted that perldebguts will tell you a lot about
787 # the underlying mechanics of how the debugger interfaces into the
788 # Perl interpreter, but not a lot about the debugger itself. The new
789 # comments in this code try to address this problem.)
791 # Note that no subroutine call is possible until &DB::sub is defined
792 # (for subroutines defined outside of the package DB). In fact the same is
793 # true if $deep is not defined.
795 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
797 # modified Perl debugger, to be run from Emacs in perldb-mode
798 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
799 # Johan Vromans -- upgrade to 4.0 pl 10
800 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
801 ########################################################################
803 =head1 DEBUGGER INITIALIZATION
805 The debugger starts up in phases.
809 First, it initializes the environment it wants to run in: turning off
810 warnings during its own compilation, defining variables which it will need
811 to avoid warnings later, setting itself up to not exit when the program
812 terminates, and defaulting to printing return values for the C<r> command.
816 # Needed for the statement after exec():
818 # This BEGIN block is simply used to switch off warnings during debugger
819 # compilation. Probably it would be better practice to fix the warnings,
820 # but this is how it's done at the moment.
825 } # Switch compilation warnings off until another BEGIN.
827 local ($^W) = 0; # Switch run-time warnings off during init.
829 =head2 THREADS SUPPORT
831 If we are running under a threaded Perl, we require threads and threads::shared
832 if the environment variable C<PERL5DB_THREADED> is set, to enable proper
833 threaded debugger control. C<-dt> can also be used to set this.
835 Each new thread will be announced and the debugger prompt will always inform
836 you of each new thread created. It will also indicate the thread id in which
837 we are currently running within the prompt like this:
841 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
842 command prompt. The prompt will show: C<[0]> when running under threads, but
843 not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
845 While running under threads, when you set or delete a breakpoint (etc.), this
846 will apply to all threads, not just the currently running one. When you are
847 in a currently executing thread, you will stay there until it completes. With
848 the current implementation it is not currently possible to hop from one thread
851 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
853 Note that threading support was built into the debugger as of Perl version
854 C<5.8.6> and debugger version C<1.2.8>.
859 # ensure we can share our non-threaded variables or no-op
860 if ($ENV{PERL5DB_THREADED}) {
862 require threads::shared;
863 import threads::shared qw(share);
867 print "Threads support enabled\n";
874 # These variables control the execution of 'dumpvar.pl'.
889 # used to control die() reporting in diesignal()
892 use vars qw($CarpLevel);
895 # without threads, $filename is not defined until DB::DB is called
896 foreach my $k (keys (%INC)) {
897 share(\$main::{'_<'.$filename}) if defined $filename;
900 # Command-line + PERLLIB:
901 # Save the contents of @INC before they are modified elsewhere.
904 # This was an attempt to clear out the previous values of various
905 # trapped errors. Apparently it didn't help. XXX More info needed!
906 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
908 # We set these variables to safe values. We don't want to blindly turn
909 # off warnings, because other packages may still want them.
910 $trace = $signal = $single = 0; # Uninitialized warning suppression
911 # (local $^W cannot help - other packages!).
913 # Default to not exiting when program finishes; print the return
914 # value when the 'r' command is used to return from a subroutine.
915 $inhibit_exit = $option{PrintRet} = 1;
917 use vars qw($trace_to_depth);
919 # Default to 1E9 so it won't be limited to a certain recursion depth.
920 $trace_to_depth = 1E9;
922 =head1 OPTION PROCESSING
924 The debugger's options are actually spread out over the debugger itself and
925 C<dumpvar.pl>; some of these are variables to be set, while others are
926 subs to be called with a value. To try to make this a little easier to
927 manage, the debugger uses a few data structures to define what options
928 are legal and how they are to be processed.
930 First, the C<@options> array defines the I<names> of all the options that
936 CommandSet HistFile HistSize
937 hashDepth arrayDepth dumpDepth
938 DumpDBFiles DumpPackages DumpReused
939 compactDump veryCompact quote
940 HighBit undefPrint globPrint
941 PrintRet UsageOnly frame
943 ReadLine NonStop LineInfo
944 maxTraceLen recallCommand ShellBang
945 pager tkRunning ornaments
946 signalLevel warnLevel dieLevel
947 inhibit_exit ImmediateStop bareStringify
948 CreateTTY RemotePort windowSize
952 @RememberOnROptions = qw(DollarCaretP);
956 Second, C<optionVars> lists the variables that each option uses to save its
961 use vars qw(%optionVars);
964 hashDepth => \$dumpvar::hashDepth,
965 arrayDepth => \$dumpvar::arrayDepth,
966 CommandSet => \$CommandSet,
967 DumpDBFiles => \$dumpvar::dumpDBFiles,
968 DumpPackages => \$dumpvar::dumpPackages,
969 DumpReused => \$dumpvar::dumpReused,
970 HighBit => \$dumpvar::quoteHighBit,
971 undefPrint => \$dumpvar::printUndef,
972 globPrint => \$dumpvar::globPrint,
973 UsageOnly => \$dumpvar::usageOnly,
974 CreateTTY => \$CreateTTY,
975 bareStringify => \$dumpvar::bareStringify,
977 AutoTrace => \$trace,
978 inhibit_exit => \$inhibit_exit,
979 maxTraceLen => \$maxtrace,
980 ImmediateStop => \$ImmediateStop,
981 RemotePort => \$remoteport,
982 windowSize => \$window,
983 HistFile => \$histfile,
984 HistSize => \$histsize,
989 Third, C<%optionAction> defines the subroutine to be called to process each
994 use vars qw(%optionAction);
997 compactDump => \&dumpvar::compactDump,
998 veryCompact => \&dumpvar::veryCompact,
999 quote => \&dumpvar::quote,
1002 ReadLine => \&ReadLine,
1003 NonStop => \&NonStop,
1004 LineInfo => \&LineInfo,
1005 recallCommand => \&recallCommand,
1006 ShellBang => \&shellBang,
1008 signalLevel => \&signalLevel,
1009 warnLevel => \&warnLevel,
1010 dieLevel => \&dieLevel,
1011 tkRunning => \&tkRunning,
1012 ornaments => \&ornaments,
1013 RemotePort => \&RemotePort,
1014 DollarCaretP => \&DollarCaretP,
1019 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1024 # Note that this list is not complete: several options not listed here
1025 # actually require that dumpvar.pl be loaded for them to work, but are
1026 # not in the table. A subsequent patch will correct this problem; for
1027 # the moment, we're just recommenting, and we are NOT going to change
1029 use vars qw(%optionRequire);
1032 compactDump => 'dumpvar.pl',
1033 veryCompact => 'dumpvar.pl',
1034 quote => 'dumpvar.pl',
1039 There are a number of initialization-related variables which can be set
1040 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1041 variable. These are:
1045 =item C<$rl> - readline control XXX needs more explanation
1047 =item C<$warnLevel> - whether or not debugger takes over warning handling
1049 =item C<$dieLevel> - whether or not debugger takes over die handling
1051 =item C<$signalLevel> - whether or not debugger takes over signal handling
1053 =item C<$pre> - preprompt actions (array reference)
1055 =item C<$post> - postprompt actions (array reference)
1059 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1061 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1067 # These guys may be defined in $ENV{PERL5DB} :
1068 $rl = 1 unless defined $rl;
1069 $warnLevel = 1 unless defined $warnLevel;
1070 $dieLevel = 1 unless defined $dieLevel;
1071 $signalLevel = 1 unless defined $signalLevel;
1072 $pre = [] unless defined $pre;
1073 $post = [] unless defined $post;
1074 $pretype = [] unless defined $pretype;
1075 $CreateTTY = 3 unless defined $CreateTTY;
1076 $CommandSet = '580' unless defined $CommandSet;
1081 share($signalLevel);
1091 The default C<die>, C<warn>, and C<signal> handlers are set up.
1095 warnLevel($warnLevel);
1096 dieLevel($dieLevel);
1097 signalLevel($signalLevel);
1101 The pager to be used is needed next. We try to get it from the
1102 environment first. If it's not defined there, we try to find it in
1103 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1104 then call the C<pager()> function to save the pager name.
1108 # This routine makes sure $pager is set up so that '|' can use it.
1111 # If PAGER is defined in the environment, use it.
1115 # If not, see if Config.pm defines it.
1116 : eval { require Config }
1117 && defined $Config::Config{pager}
1118 ? $Config::Config{pager}
1120 # If not, fall back to 'more'.
1123 unless defined $pager;
1127 We set up the command to be used to access the man pages, the command
1128 recall character (C<!> unless otherwise defined) and the shell escape
1129 character (C<!> unless otherwise defined). Yes, these do conflict, and
1130 neither works in the debugger at the moment.
1136 # Set up defaults for command recall and shell escape (note:
1137 # these currently don't work in linemode debugging).
1138 recallCommand("!") unless defined $prc;
1139 shellBang("!") unless defined $psh;
1143 We then set up the gigantic string containing the debugger help.
1144 We also set the limit on the number of arguments we'll display during a
1151 # If we didn't get a default for the length of eval/stack trace args,
1153 $maxtrace = 400 unless defined $maxtrace;
1155 =head2 SETTING UP THE DEBUGGER GREETING
1157 The debugger I<greeting> helps to inform the user how many debuggers are
1158 running, and whether the current debugger is the primary or a child.
1160 If we are the primary, we just hang onto our pid so we'll have it when
1161 or if we start a child debugger. If we are a child, we'll set things up
1162 so we'll have a unique greeting and so the parent will give us our own
1165 We save the current contents of the C<PERLDB_PIDS> environment variable
1166 because we mess around with it. We'll also need to hang onto it because
1167 we'll need it if we restart.
1169 Child debuggers make a label out of the current PID structure recorded in
1170 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1171 yet so the parent will give them one later via C<resetterm()>.
1175 # Save the current contents of the environment; we're about to
1176 # much with it. We'll need this if we have to restart.
1177 use vars qw($ini_pids);
1178 $ini_pids = $ENV{PERLDB_PIDS};
1180 use vars qw ($pids $term_pid);
1182 if ( defined $ENV{PERLDB_PIDS} ) {
1184 # We're a child. Make us a label out of the current PID structure
1185 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1186 # a term yet so the parent will give us one later via resetterm().
1188 my $env_pids = $ENV{PERLDB_PIDS};
1189 $pids = "[$env_pids]";
1191 # Unless we are on OpenVMS, all programs under the DCL shell run under
1194 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1198 $ENV{PERLDB_PIDS} .= "->$$";
1202 } ## end if (defined $ENV{PERLDB_PIDS...
1205 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1206 # child debugger, and mark us as the parent, so we'll know to set up
1207 # more TTY's is we have to.
1208 $ENV{PERLDB_PIDS} = "$$";
1213 use vars qw($pidprompt);
1216 # Sets up $emacs as a synonym for $slave_editor.
1217 our ($slave_editor);
1218 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1220 =head2 READING THE RC FILE
1222 The debugger will read a file of initialization options if supplied. If
1223 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1227 # As noted, this test really doesn't check accurately that the debugger
1228 # is running at a terminal or not.
1230 use vars qw($rcfile);
1232 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1233 # this is the wrong metric!
1234 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
1239 The debugger does a safety test of the file to be read. It must be owned
1240 either by the current user or root, and must only be writable by the owner.
1244 # This wraps a safety test around "do" to read and evaluate the init file.
1246 # This isn't really safe, because there's a race
1247 # between checking and opening. The solution is to
1248 # open and fstat the handle, but then you have to read and
1249 # eval the contents. But then the silly thing gets
1250 # your lexical scope, which is unfortunate at best.
1254 # Just exactly what part of the word "CORE::" don't you understand?
1255 local $SIG{__WARN__};
1256 local $SIG{__DIE__};
1258 unless ( is_safe_file($file) ) {
1259 CORE::warn <<EO_GRIPE;
1260 perldb: Must not source insecure rcfile $file.
1261 You or the superuser must be the owner, and it must not
1262 be writable by anyone but its owner.
1265 } ## end unless (is_safe_file($file...
1268 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1269 } ## end sub safe_do
1271 # This is the safety test itself.
1273 # Verifies that owner is either real user or superuser and that no
1274 # one but owner may write to it. This function is of limited use
1275 # when called on a path instead of upon a handle, because there are
1276 # no guarantees that filename (by dirent) whose file (by ino) is
1277 # eventually accessed is the same as the one tested.
1278 # Assumes that the file's existence is not in doubt.
1281 stat($path) || return; # mysteriously vaporized
1282 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1284 return 0 if $uid != 0 && $uid != $<;
1285 return 0 if $mode & 022;
1287 } ## end sub is_safe_file
1289 # If the rcfile (whichever one we decided was the right one to read)
1290 # exists, we safely do it.
1292 safe_do("./$rcfile");
1295 # If there isn't one here, try the user's home directory.
1296 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1297 safe_do("$ENV{HOME}/$rcfile");
1300 # Else try the login directory.
1301 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1302 safe_do("$ENV{LOGDIR}/$rcfile");
1305 # If the PERLDB_OPTS variable has options in it, parse those out next.
1306 if ( defined $ENV{PERLDB_OPTS} ) {
1307 parse_options( $ENV{PERLDB_OPTS} );
1312 The last thing we do during initialization is determine which subroutine is
1313 to be used to obtain a new terminal when a new debugger is started. Right now,
1314 the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
1319 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1320 # Works if you're running an xterm or xterm-like window, or you're on
1321 # OS/2, or on Mac OS X. This may need some expansion.
1323 if (not defined &get_fork_TTY) # only if no routine exists
1325 if ( defined $remoteport ) {
1326 # Expect an inetd-like server
1327 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1329 elsif (defined $ENV{TERM} # If we know what kind
1330 # of terminal this is,
1331 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1332 and defined $ENV{DISPLAY} # and what display it's on,
1335 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1337 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1338 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1340 elsif ( $^O eq 'darwin' # If this is Mac OS X
1341 and defined $ENV{TERM_PROGRAM} # and we're running inside
1342 and $ENV{TERM_PROGRAM}
1343 eq 'Apple_Terminal' # Terminal.app
1346 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1348 } ## end if (not defined &get_fork_TTY...
1350 # untaint $^O, which may have been tainted by the last statement.
1351 # see bug [perl #24674]
1355 # Here begin the unreadable code. It needs fixing.
1357 =head2 RESTART PROCESSING
1359 This section handles the restart command. When the C<R> command is invoked, it
1360 tries to capture all of the state it can into environment variables, and
1361 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1362 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1363 the R command stuffed into the environment variables.
1365 PERLDB_RESTART - flag only, contains no restart data itself.
1366 PERLDB_HIST - command history, if it's available
1367 PERLDB_ON_LOAD - breakpoints set by the rc file
1368 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1369 PERLDB_VISITED - files that had breakpoints
1370 PERLDB_FILE_... - breakpoints for a file
1371 PERLDB_OPT - active options
1372 PERLDB_INC - the original @INC
1373 PERLDB_PRETYPE - preprompt debugger actions
1374 PERLDB_PRE - preprompt Perl code
1375 PERLDB_POST - post-prompt Perl code
1376 PERLDB_TYPEAHEAD - typeahead captured by readline()
1378 We chug through all these variables and plug the values saved in them
1379 back into the appropriate spots in the debugger.
1383 use vars qw(@hist @truehist %postponed_file @typeahead);
1385 sub _restore_shared_globals_after_restart
1387 @hist = get_list('PERLDB_HIST');
1388 %break_on_load = get_list("PERLDB_ON_LOAD");
1389 %postponed = get_list("PERLDB_POSTPONE");
1393 share(%break_on_load);
1397 sub _restore_breakpoints_and_actions {
1399 my @had_breakpoints = get_list("PERLDB_VISITED");
1401 for my $file_idx ( 0 .. $#had_breakpoints ) {
1402 my $filename = $had_breakpoints[$file_idx];
1403 my %pf = get_list("PERLDB_FILE_$file_idx");
1404 $postponed_file{ $filename } = \%pf if %pf;
1405 my @lines = sort {$a <=> $b} keys(%pf);
1406 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1407 for my $line_idx (0 .. $#lines) {
1408 _set_breakpoint_enabled_status(
1411 ($enabled_statuses[$line_idx] ? 1 : ''),
1419 sub _restore_options_after_restart
1421 my %options_map = get_list("PERLDB_OPT");
1423 while ( my ( $opt, $val ) = each %options_map ) {
1424 $val =~ s/[\\\']/\\$1/g;
1425 parse_options("$opt'$val'");
1431 sub _restore_globals_after_restart
1433 # restore original @INC
1434 @INC = get_list("PERLDB_INC");
1437 # return pre/postprompt actions and typeahead buffer
1438 $pretype = [ get_list("PERLDB_PRETYPE") ];
1439 $pre = [ get_list("PERLDB_PRE") ];
1440 $post = [ get_list("PERLDB_POST") ];
1441 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1447 if ( exists $ENV{PERLDB_RESTART} ) {
1449 # We're restarting, so we don't need the flag that says to restart anymore.
1450 delete $ENV{PERLDB_RESTART};
1453 _restore_shared_globals_after_restart();
1455 _restore_breakpoints_and_actions();
1458 _restore_options_after_restart();
1460 _restore_globals_after_restart();
1461 } ## end if (exists $ENV{PERLDB_RESTART...
1463 =head2 SETTING UP THE TERMINAL
1465 Now, we'll decide how the debugger is going to interact with the user.
1466 If there's no TTY, we set the debugger to run non-stop; there's not going
1467 to be anyone there to enter commands.
1471 use vars qw($notty $console $tty $LINEINFO);
1472 use vars qw($lineinfo $doccmd);
1483 If there is a TTY, we have to determine who it belongs to before we can
1484 proceed. If this is a slave editor or graphical debugger (denoted by
1485 the first command-line switch being '-emacs'), we shift this off and
1486 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1492 # Is Perl being run from a slave editor or graphical debugger?
1493 # If so, don't use readline, and set $slave_editor = 1.
1494 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1499 #require Term::ReadLine;
1503 We then determine what the console should be on various systems:
1507 =item * Cygwin - We use C<stdin> instead of a separate device.
1511 if ( $^O eq 'cygwin' ) {
1513 # /dev/tty is binary. use stdin for textmode
1517 =item * Unix - use C</dev/tty>.
1521 elsif ( -e "/dev/tty" ) {
1522 $console = "/dev/tty";
1525 =item * Windows or MSDOS - use C<con>.
1529 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1533 =item * VMS - use C<sys$command>.
1539 # everything else is ...
1540 $console = "sys\$command";
1547 Several other systems don't use a specific console. We C<undef $console>
1548 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1549 with a slave editor, Epoc).
1553 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1555 # /dev/tty is binary. use stdin for textmode
1559 if ( $^O eq 'NetWare' ) {
1561 # /dev/tty is binary. use stdin for textmode
1565 # In OS/2, we need to use STDIN to get textmode too, even though
1566 # it pretty much looks like Unix otherwise.
1567 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1572 # EPOC also falls into the 'got to use STDIN' camp.
1573 if ( $^O eq 'epoc' ) {
1579 If there is a TTY hanging around from a parent, we use that as the console.
1583 $console = $tty if defined $tty;
1585 =head2 SOCKET HANDLING
1587 The debugger is capable of opening a socket and carrying out a debugging
1588 session over the socket.
1590 If C<RemotePort> was defined in the options, the debugger assumes that it
1591 should try to start a debugging session on that port. It builds the socket
1592 and then tries to connect the input and output filehandles to it.
1596 # Handle socket stuff.
1598 if ( defined $remoteport ) {
1600 # If RemotePort was defined in the options, connect input and output
1602 $IN = $OUT = connect_remoteport();
1603 } ## end if (defined $remoteport)
1607 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1608 this is probably a situation where multiple debuggers are running (for example,
1609 a backticked command that starts up another debugger). We create a new IN and
1610 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1618 # Two debuggers running (probably a system or a backtick that invokes
1619 # the debugger itself under the running one). create a new IN and OUT
1620 # filehandle, and do the necessary mojo to create a new tty if we
1621 # know how, and we can.
1622 create_IN_OUT(4) if $CreateTTY & 4;
1625 # If we have a console, check to see if there are separate ins and
1626 # outs to open. (They are assumed identical if not.)
1628 my ( $i, $o ) = split /,/, $console;
1629 $o = $i unless defined $o;
1631 # read/write on in, or just read, or read on STDIN.
1633 || open( IN, "<$i" )
1634 || open( IN, "<&STDIN" );
1636 # read/write/create/clobber out, or write/create/clobber out,
1637 # or merge with STDERR, or merge with STDOUT.
1639 || open( OUT, ">$o" )
1640 || open( OUT, ">&STDERR" )
1641 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1643 } ## end if ($console)
1644 elsif ( not defined $console ) {
1646 # No console. Open STDIN.
1647 open( IN, "<&STDIN" );
1649 # merge with STDERR, or with STDOUT.
1650 open( OUT, ">&STDERR" )
1651 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1652 $console = 'STDIN/OUT';
1653 } ## end elsif (not defined $console)
1655 # Keep copies of the filehandles so that when the pager runs, it
1656 # can close standard input without clobbering ours.
1657 if ($console or (not defined($console))) {
1661 } ## end elsif (from if(defined $remoteport))
1663 # Unbuffer DB::OUT. We need to see responses right away.
1666 # Line info goes to debugger output unless pointed elsewhere.
1667 # Pointing elsewhere makes it possible for slave editors to
1668 # keep track of file and position. We have both a filehandle
1669 # and a I/O description to keep track of.
1670 $LINEINFO = $OUT unless defined $LINEINFO;
1671 $lineinfo = $console unless defined $lineinfo;
1672 # share($LINEINFO); # <- unable to share globs
1677 To finish initialization, we show the debugger greeting,
1678 and then call the C<afterinit()> subroutine if there is one.
1682 # Show the debugger greeting.
1683 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1684 unless ($runnonstop) {
1687 if ( $term_pid eq '-1' ) {
1688 print $OUT "\nDaughter DB session started...\n";
1691 print $OUT "\nLoading DB routines from $header\n";
1694 $slave_editor ? "enabled" : "available", ".\n"
1697 "\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
1698 } ## end else [ if ($term_pid eq '-1')
1699 } ## end unless ($runnonstop)
1700 } ## end else [ if ($notty)
1702 # XXX This looks like a bug to me.
1703 # Why copy to @ARGS and then futz with @args?
1706 # Make sure backslashes before single quotes are stripped out, and
1707 # keep args unless they are numeric (XXX why?)
1708 # s/\'/\\\'/g; # removed while not justified understandably
1709 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1712 # If there was an afterinit() sub defined, call it. It will get
1713 # executed in our scope, so it can fiddle with debugger globals.
1714 if ( defined &afterinit ) { # May be defined in $rcfile
1718 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1719 use vars qw($I_m_init);
1723 ############################################################ Subroutines
1729 This gigantic subroutine is the heart of the debugger. Called before every
1730 statement, its job is to determine if a breakpoint has been reached, and
1731 stop if so; read commands from the user, parse them, and execute
1732 them, and then send execution off to the next statement.
1734 Note that the order in which the commands are processed is very important;
1735 some commands earlier in the loop will actually alter the C<$cmd> variable
1736 to create other commands to be executed later. This is all highly I<optimized>
1737 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1738 see what's happening in any given command.
1770 sub _DB__determine_if_we_should_break
1772 # if we have something here, see if we should break.
1773 # $stop is lexical and local to this block - $action on the other hand
1778 && _is_breakpoint_enabled($filename, $line)
1779 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1782 # Stop if the stop criterion says to just stop.
1783 if ( $stop eq '1' ) {
1787 # It's a conditional stop; eval it in the user's context and
1788 # see if we should stop. If so, remove the one-time sigil.
1790 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1792 # If the breakpoint is temporary, then delete its enabled status.
1793 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1794 _cancel_breakpoint_temp_enabled_status($filename, $line);
1797 } ## end if ($dbline{$line} && ...
1800 sub _DB__is_finished {
1801 if ($finished and $level <= 1) {
1810 sub _DB__read_next_cmd
1814 # We have a terminal, or can get one ...
1819 # ... and it belogs to this PID or we get one for this PID ...
1820 if ($term_pid != $$) {
1824 # ... and we got a line of command input ...
1825 $cmd = DB::readline(
1826 "$pidprompt $tid DB"
1829 . ( '>' x $level ) . " "
1832 return defined($cmd);
1835 sub _DB__trim_command_and_return_first_component {
1836 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1837 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1843 sub _DB__handle_f_command {
1844 if (($file) = $cmd =~ /\Af\b\s*(.*)/) {
1847 # help for no arguments (old-style was return from sub).
1850 "The old f command is now the r command.\n"; # hint
1851 print $OUT "The new f command switches filenames.\n";
1853 } ## end if (!$file)
1855 # if not in magic file list, try a close match.
1856 if ( !defined $main::{ '_<' . $file } ) {
1857 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
1859 $try = substr( $try, 2 );
1860 print $OUT "Choosing $try matching '$file':\n";
1863 } ## end if (($try) = grep(m#^_<.*$file#...
1864 } ## end if (!defined $main::{ ...
1866 # If not successfully switched now, we failed.
1867 if ( !defined $main::{ '_<' . $file } ) {
1868 print $OUT "No file matching '$file' is loaded.\n";
1872 # We switched, so switch the debugger internals around.
1873 elsif ( $file ne $filename ) {
1874 *dbline = $main::{ '_<' . $file };
1879 } ## end elsif ($file ne $filename)
1881 # We didn't switch; say we didn't.
1883 print $OUT "Already in $file.\n";
1891 sub _DB__handle_dot_command {
1896 $incr = -1; # stay at current line
1898 # Reset everything to the old location.
1900 $filename = $filename_ini;
1901 *dbline = $main::{ '_<' . $filename };
1905 print_lineinfo($obj->position());
1912 sub _DB__handle_y_command {
1915 if (my ($match_level, $match_vars)
1916 = $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/) {
1918 # See if we've got the necessary support.
1919 eval { require PadWalker; PadWalker->VERSION(0.08) }
1922 ? "PadWalker module not found - please install\n"
1927 # Load up dumpvar if we don't have it. If we can, that is.
1928 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
1929 defined &main::dumpvar
1930 or print $OUT "dumpvar.pl not available.\n"
1933 # Got all the modules we need. Find them and print them.
1934 my @vars = split( ' ', $match_vars || '' );
1937 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 1 ) };
1939 # Oops. Can't find it.
1940 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
1942 # Show the desired vars with dumplex().
1943 my $savout = select($OUT);
1945 # Have dumplex dump the lexicals.
1946 dumpvar::dumplex( $_, $h->{$_},
1947 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
1957 # lock the debugger and get the thread id for the prompt
1961 my ($prefix, $after, $infix);
1965 if ($ENV{PERL5DB_THREADED}) {
1966 $tid = eval { "[".threads->tid."]" };
1969 my $obj = DB::Obj->new(
1971 position => \$position,
1974 explicit_stop => \$explicit_stop,
1979 $obj->_DB_on_init__initialize_globals(@_);
1981 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1982 # The code being debugged may have altered them.
1985 # Since DB::DB gets called after every line, we can use caller() to
1986 # figure out where we last were executing. Sneaky, eh? This works because
1987 # caller is returning all the extra information when called from the
1989 local ( $package, $filename, $line ) = caller;
1990 $filename_ini = $filename;
1992 # set up the context for DB::eval, so it can properly execute
1993 # code on behalf of the user. We add the package in so that the
1994 # code is eval'ed in the proper package (not in the debugger!).
1995 local $usercontext = _calc_usercontext($package);
1997 # Create an alias to the active file magical array to simplify
1999 local (*dbline) = $main::{ '_<' . $filename };
2001 # Last line in the program.
2004 _DB__determine_if_we_should_break(@_);
2006 # Preserve the current stop-or-not, and see if any of the W
2007 # (watch expressions) has changed.
2008 my $was_signal = $signal;
2010 # If we have any watch expressions ...
2011 $obj->_DB__handle_watch_expressions(@_);
2013 =head2 C<watchfunction()>
2015 C<watchfunction()> is a function that can be defined by the user; it is a
2016 function which will be run on each entry to C<DB::DB>; it gets the
2017 current package, filename, and line as its parameters.
2019 The watchfunction can do anything it likes; it is executing in the
2020 debugger's context, so it has access to all of the debugger's internal
2021 data structures and functions.
2023 C<watchfunction()> can control the debugger's actions. Any of the following
2024 will cause the debugger to return control to the user's program after
2025 C<watchfunction()> executes:
2031 Returning a false value from the C<watchfunction()> itself.
2035 Altering C<$single> to a false value.
2039 Altering C<$signal> to a false value.
2043 Turning off the C<4> bit in C<$trace> (this also disables the
2044 check for C<watchfunction()>. This can be done with
2052 # If there's a user-defined DB::watchfunction, call it with the
2053 # current package, filename, and line. The function executes in
2055 if ( $trace & 4 ) { # User-installed watch
2057 if watchfunction( $package, $filename, $line )
2060 and not( $trace & ~4 );
2061 } ## end if ($trace & 4)
2063 # Pick up any alteration to $signal in the watchfunction, and
2064 # turn off the signal now.
2065 $was_signal = $signal;
2068 =head2 GETTING READY TO EXECUTE COMMANDS
2070 The debugger decides to take control if single-step mode is on, the
2071 C<t> command was entered, or the user generated a signal. If the program
2072 has fallen off the end, we set things up so that entering further commands
2073 won't cause trouble, and we say that the program is over.
2077 # Make sure that we always print if asked for explicitly regardless
2078 # of $trace_to_depth .
2079 $explicit_stop = ($single || $was_signal);
2081 # Check to see if we should grab control ($single true,
2082 # trace set appropriately, or we got a signal).
2083 if ( $explicit_stop || ( $trace & 1 ) ) {
2084 $obj->_DB__grab_control(@_);
2085 } ## end if ($single || ($trace...
2089 If there's an action to be executed for the line we stopped at, execute it.
2090 If there are any preprompt actions, execute those as well.
2094 # If there's an action, do it now.
2100 # Are we nested another level (e.g., did we evaluate a function
2101 # that had a breakpoint in it at the debugger prompt)?
2102 if ( $single || $was_signal ) {
2104 # Yes, go down a level.
2105 local $level = $level + 1;
2107 # Do any pre-prompt actions.
2108 foreach $evalarg (@$pre) {
2112 # Complain about too much recursion if we passed the limit.
2114 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2117 # The line we're currently on. Set $incr to -1 to stay here
2118 # until we get a command that tells us to advance.
2120 $incr = -1; # for backward motion.
2122 # Tack preprompt debugger actions ahead of any actual input.
2123 @typeahead = ( @$pretype, @typeahead );
2125 =head2 WHERE ARE WE?
2127 XXX Relocate this section?
2129 The debugger normally shows the line corresponding to the current line of
2130 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2131 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2133 C<$incr> controls by how many lines the I<current> line should move forward
2134 after a command is executed. If set to -1, this indicates that the I<current>
2135 line shouldn't change.
2137 C<$start> is the I<current> line. It is used for things like knowing where to
2138 move forwards or backwards from when doing an C<L> or C<-> command.
2140 C<$max> tells the debugger where the last line of the current file is. It's
2141 used to terminate loops most often.
2143 =head2 THE COMMAND LOOP
2145 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2152 The outer part of the loop, starting at the C<CMD> label. This loop
2153 reads a command and then executes it.
2157 The inner part of the loop, starting at the C<PIPE> label. This part
2158 is wholly contained inside the C<CMD> block and only executes a command.
2159 Used to handle commands running inside a pager.
2163 So why have two labels to restart the loop? Because sometimes, it's easier to
2164 have a command I<generate> another command and then re-execute the loop to do
2165 the new command. This is faster, but perhaps a bit more convoluted.
2169 # The big command dispatch loop. It keeps running until the
2170 # user yields up control again.
2172 # If we have a terminal for input, and we get something back
2173 # from readline(), keep on processing.
2178 while (_DB__read_next_cmd($tid))
2182 # ... try to execute the input as debugger commands.
2184 # Don't stop running.
2187 # No signal is active.
2190 # Handle continued commands (ending with \):
2191 if ($cmd =~ s/\\\z/\n/) {
2192 $cmd .= DB::readline(" cont: ");
2196 =head4 The null command
2198 A newline entered by itself means I<re-execute the last command>. We grab the
2199 command out of C<$laststep> (where it was recorded previously), and copy it
2200 back into C<$cmd> to be executed below. If there wasn't any previous command,
2201 we'll do nothing below (no command will match). If there was, we also save it
2202 in the command history and fall through to allow the command parsing to pick
2207 # Empty input means repeat the last command.
2211 chomp($cmd); # get rid of the annoying extra newline
2212 if (length($cmd) >= 2) {
2213 push( @hist, $cmd );
2215 push( @truehist, $cmd );
2219 # This is a restart point for commands that didn't arrive
2220 # via direct user input. It allows us to 'redo PIPE' to
2221 # re-execute command processing without reading a new command.
2223 my $i = _DB__trim_command_and_return_first_component();
2225 =head3 COMMAND ALIASES
2227 The debugger can create aliases for commands (these are stored in the
2228 C<%alias> hash). Before a command is executed, the command loop looks it up
2229 in the alias hash and substitutes the contents of the alias for the command,
2230 completely replacing it.
2234 # See if there's an alias for the command, and set it up if so.
2237 # Squelch signal handling; we want to keep control here
2238 # if something goes loco during the alias eval.
2239 local $SIG{__DIE__};
2240 local $SIG{__WARN__};
2242 # This is a command, so we eval it in the DEBUGGER's
2243 # scope! Otherwise, we can't see the special debugger
2244 # variables, or get to the debugger's subs. (Well, we
2245 # _could_, but why make it even more complicated?)
2246 eval "\$cmd =~ $alias{$i}";
2249 print $OUT "Couldn't evaluate '$i' alias: $@";
2252 } ## end if ($alias{$i})
2254 =head3 MAIN-LINE COMMANDS
2256 All of these commands work up to and after the program being debugged has
2261 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2262 try to execute further, cleaning any restart-related stuff out of the
2263 environment, and executing with the last value of C<$?>.
2273 =head4 C<t> - trace [n]
2275 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2276 If level is specified, set C<$trace_to_depth>.
2280 $obj->_handle_t_command;
2282 =head4 C<S> - list subroutines matching/not matching a pattern
2284 Walks through C<%sub>, checking to see whether or not to print the name.
2288 $obj->_handle_S_command;
2290 =head4 C<X> - list variables in current package
2292 Since the C<V> command actually processes this, just change this to the
2293 appropriate C<V> command and fall through.
2295 =head4 C<V> - list variables
2297 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2301 $obj->_handle_V_command_and_X_command;
2303 =head4 C<x> - evaluate and print an expression
2305 Hands the expression off to C<DB::eval>, setting it up to print the value
2306 via C<dumpvar.pl> instead of just printing it directly.
2310 if ($cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
2311 $onetimeDump = 'dump'; # main::dumpvar shows the output
2313 # handle special "x 3 blah" syntax XXX propagate
2314 # doc back to special variables.
2315 if ( $cmd =~ s#\A\s*(\d+)(?=\s)# #) {
2316 $onetimedumpDepth = $1;
2320 =head4 C<m> - print methods
2322 Just uses C<DB::methods> to determine what methods are available.
2326 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2331 # m expr - set up DB::eval to do the work
2332 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2333 $onetimeDump = 'methods'; # method output gets used there
2336 =head4 C<f> - switch files
2340 _DB__handle_f_command();
2342 =head4 C<.> - return to last-executed line.
2344 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2345 and then we look up the line in the magical C<%dbline> hash.
2349 _DB__handle_dot_command($obj);
2351 =head4 C<-> - back one window
2353 We change C<$start> to be one window back; if we go back past the first line,
2354 we set it to be the first line. We ser C<$incr> to put us back at the
2355 currently-executing line, and then put a C<l $start +> (list one window from
2356 C<$start>) in C<$cmd> to be executed later.
2360 # - - back a window.
2361 $obj->_handle_dash_command;
2363 =head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
2365 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2366 problems, most notably that the default case of several commands destroying
2367 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2368 retain the old commands for those who were used to using them or who preferred
2369 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2370 deal with them instead of processing them in-line.
2374 # All of these commands were remapped in perl 5.8.0;
2375 # we send them off to the secondary dispatcher (see below).
2376 if (my ($cmd_letter, $my_arg) = $cmd =~ /\A([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so) {
2377 &cmd_wrapper( $cmd_letter, $my_arg, $line );
2381 =head4 C<y> - List lexicals in higher scope
2383 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2384 above the current one and then displays then using C<dumpvar.pl>.
2388 _DB__handle_y_command($obj);
2390 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2392 All of the commands below this point don't work after the program being
2393 debugged has ended. All of them check to see if the program has ended; this
2394 allows the commands to be relocated without worrying about a 'line of
2395 demarcation' above which commands can be entered anytime, and below which
2398 =head4 C<n> - single step, but don't trace down into subs
2400 Done by setting C<$single> to 2, which forces subs to execute straight through
2401 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2402 so a null command knows what to re-execute.
2408 next CMD if _DB__is_finished();
2410 # Single step, but don't enter subs.
2413 # Save for empty command (repeat last).
2418 =head4 C<s> - single-step, entering subs
2420 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2421 subs. Also saves C<s> as C<$lastcmd>.
2428 # Get out and restart the command loop if program
2430 next CMD if _DB__is_finished();
2432 # Single step should enter subs.
2435 # Save for empty command (repeat last).
2440 =head4 C<c> - run continuously, setting an optional breakpoint
2442 Most of the code for this command is taken up with locating the optional
2443 breakpoint, which is either a subroutine name or a line number. We set
2444 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2445 in this and all call levels above this one.
2449 # c - start continuous execution.
2450 if (($i) = $cmd =~ m#\Ac\b\s*([\w:]*)\s*\z#) {
2452 # Hey, show's over. The debugged program finished
2453 # executing already.
2454 next CMD if _DB__is_finished();
2456 # Capture the place to put a one-time break.
2459 # Probably not needed, since we finish an interactive
2460 # sub-session anyway...
2461 # local $filename = $filename;
2462 # local *dbline = *dbline; # XXX Would this work?!
2464 # The above question wonders if localizing the alias
2465 # to the magic array works or not. Since it's commented
2466 # out, we'll just leave that to speculation for now.
2468 # If the "subname" isn't all digits, we'll assume it
2469 # is a subroutine name, and try to find it.
2470 if ( $subname =~ /\D/ ) { # subroutine name
2471 # Qualify it to the current package unless it's
2472 # already qualified.
2473 $subname = $package . "::" . $subname
2474 unless $subname =~ /::/;
2476 # find_sub will return "file:line_number" corresponding
2477 # to where the subroutine is defined; we call find_sub,
2478 # break up the return value, and assign it in one
2480 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2482 # Force the line number to be numeric.
2485 # If we got a line number, we found the sub.
2488 # Switch all the debugger's internals around so
2489 # we're actually working with that file.
2491 *dbline = $main::{ '_<' . $filename };
2493 # Mark that there's a breakpoint in this file.
2494 $had_breakpoints{$filename} |= 1;
2496 # Scan forward to the first executable line
2497 # after the 'sub whatever' line.
2499 ++$i while $dbline[$i] == 0 && $i < $max;
2502 # We didn't find a sub by that name.
2504 print $OUT "Subroutine $subname not found.\n";
2507 } ## end if ($subname =~ /\D/)
2509 # At this point, either the subname was all digits (an
2510 # absolute line-break request) or we've scanned through
2511 # the code following the definition of the sub, looking
2512 # for an executable, which we may or may not have found.
2514 # If $i (which we set $subname from) is non-zero, we
2515 # got a request to break at some line somewhere. On
2516 # one hand, if there wasn't any real subroutine name
2517 # involved, this will be a request to break in the current
2518 # file at the specified line, so we have to check to make
2519 # sure that the line specified really is breakable.
2521 # On the other hand, if there was a subname supplied, the
2522 # preceding block has moved us to the proper file and
2523 # location within that file, and then scanned forward
2524 # looking for the next executable line. We have to make
2525 # sure that one was found.
2527 # On the gripping hand, we can't do anything unless the
2528 # current value of $i points to a valid breakable line.
2533 if ( $dbline[$i] == 0 ) {
2534 print $OUT "Line $i not breakable.\n";
2538 # Yes. Set up the one-time-break sigil.
2539 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2540 _enable_breakpoint_temp_enabled_status($filename, $i);
2543 # Turn off stack tracing from here up.
2544 for my $i (0 .. $stack_depth) {
2550 =head4 C<r> - return from a subroutine
2552 For C<r> to work properly, the debugger has to stop execution again
2553 immediately after the return is executed. This is done by forcing
2554 single-stepping to be on in the call level above the current one. If
2555 we are printing return values when a C<r> is executed, set C<$doret>
2556 appropriately, and force us out of the command loop.
2560 # r - return from the current subroutine.
2563 # Can't do anything if the program's over.
2564 next CMD if _DB__is_finished();
2566 # Turn on stack trace.
2567 $stack[$stack_depth] |= 1;
2569 # Print return value unless the stack is empty.
2570 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2574 =head4 C<T> - stack trace
2576 Just calls C<DB::print_trace>.
2581 print_trace( $OUT, 1 ); # skip DB
2585 =head4 C<w> - List window around current line.
2587 Just calls C<DB::cmd_w>.
2591 if (my ($arg) = $cmd =~ /\Aw\b\s*(.*)/s) {
2592 &cmd_w( 'w', $arg );
2596 =head4 C<W> - watch-expression processing.
2598 Just calls C<DB::cmd_W>.
2602 if (my ($arg) = $cmd =~ /\AW\b\s*(.*)/s) {
2603 &cmd_W( 'W', $arg );
2607 =head4 C</> - search forward for a string in the source
2609 We take the argument and treat it as a pattern. If it turns out to be a
2610 bad one, we return the error we got from trying to C<eval> it and exit.
2611 If not, we create some code to do the search and C<eval> it so it can't
2616 # The pattern as a string.
2617 use vars qw($inpat);
2619 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2621 # Remove the final slash.
2622 $inpat =~ s:([^\\])/$:$1:;
2624 # If the pattern isn't null ...
2625 if ( $inpat ne "" ) {
2627 # Turn of warn and die procesing for a bit.
2628 local $SIG{__DIE__};
2629 local $SIG{__WARN__};
2631 # Create the pattern.
2632 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2635 # Oops. Bad pattern. No biscuit.
2636 # Print the eval error and go back for more
2642 } ## end if ($inpat ne "")
2644 # Set up to stop on wrap-around.
2647 # Don't move off the current line.
2650 # Done in eval so nothing breaks if the pattern
2651 # does something weird.
2655 # Move ahead one line.
2658 # Wrap if we pass the last line.
2659 $start = 1 if ($start > $max);
2661 # Stop if we have gotten back to this line again,
2662 last if ($start == $end);
2664 # A hit! (Note, though, that we are doing
2665 # case-insensitive matching. Maybe a qr//
2666 # expression would be better, so the user could
2667 # do case-sensitive matching if desired.
2668 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2669 if ($slave_editor) {
2670 # Handle proper escaping in the slave.
2671 print $OUT "\032\032$filename:$start:0\n";
2674 # Just print the line normally.
2675 print $OUT "$start:\t",$dbline[$start],"\n";
2677 # And quit since we found something.
2682 # If we wrapped, there never was a match.
2683 print $OUT "/$pat/: not found\n" if ( $start == $end );
2687 =head4 C<?> - search backward for a string in the source
2689 Same as for C</>, except the loop runs backwards.
2693 # ? - backward pattern search.
2694 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2696 # Get the pattern, remove trailing question mark.
2697 $inpat =~ s:([^\\])\?$:$1:;
2699 # If we've got one ...
2700 if ( $inpat ne "" ) {
2702 # Turn off die & warn handlers.
2703 local $SIG{__DIE__};
2704 local $SIG{__WARN__};
2705 eval '$inpat =~ m' . "\a$inpat\a";
2709 # Ouch. Not good. Print the error.
2714 } ## end if ($inpat ne "")
2716 # Where we are now is where to stop after wraparound.
2719 # Don't move away from this line.
2722 # Search inside the eval to prevent pattern badness
2730 # Wrap if we pass the first line.
2732 $start = $max if ($start <= 0);
2734 # Quit if we get back where we started,
2735 last if ($start == $end);
2738 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2739 if ($slave_editor) {
2740 # Yep, follow slave editor requirements.
2741 print $OUT "\032\032$filename:$start:0\n";
2744 # Yep, just print normally.
2745 print $OUT "$start:\t",$dbline[$start],"\n";
2753 # Say we failed if the loop never found anything,
2754 print $OUT "?$pat?: not found\n" if ( $start == $end );
2758 =head4 C<$rc> - Recall command
2760 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2761 that the terminal supports history). It find the the command required, puts it
2762 into C<$cmd>, and redoes the loop to execute it.
2766 # $rc - recall command.
2767 if (my ($minus, $arg) = $cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
2769 # No arguments, take one thing off history.
2770 pop(@hist) if length($cmd) > 1;
2772 # Relative (- found)?
2773 # Y - index back from most recent (by 1 if bare minus)
2774 # N - go to that particular command slot or the last
2775 # thing if nothing following.
2776 $i = $minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist );
2778 # Pick out the command desired.
2781 # Print the command to be executed and restart the loop
2782 # with that command in the buffer.
2783 print $OUT $cmd, "\n";
2787 =head4 C<$sh$sh> - C<system()> command
2789 Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
2790 C<STDOUT> from getting messed up.
2794 # $sh$sh - run a shell command (if it's all ASCII).
2795 # Can't run shell commands with Unicode in the debugger, hmm.
2796 if (my ($arg) = $cmd =~ m#\A$sh$sh\s*(.*)#ms) {
2803 =head4 C<$rc I<pattern> $rc> - Search command history
2805 Another command to manipulate C<@hist>: this one searches it with a pattern.
2806 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
2810 # $rc pattern $rc - find a command in the history.
2811 if (my ($arg) = $cmd =~ /\A$rc([^$rc].*)\z/) {
2813 # Create the pattern to use.
2816 # Toss off last entry if length is >1 (and it always is).
2817 pop(@hist) if length($cmd) > 1;
2819 # Look backward through the history.
2820 for ( $i = $#hist ; $i ; --$i ) {
2821 # Stop if we find it.
2822 last if $hist[$i] =~ /$pat/;
2828 print $OUT "No such command!\n\n";
2832 # Found it. Put it in the buffer, print it, and process it.
2834 print $OUT $cmd, "\n";
2838 =head4 C<$sh> - Invoke a shell
2840 Uses C<DB::system> to invoke a shell.
2844 # $sh - start a shell.
2845 if ($cmd =~ /\A$sh\z/) {
2847 # Run the user's shell. If none defined, run Bourne.
2848 # We resume execution when the shell terminates.
2849 &system( $ENV{SHELL} || "/bin/sh" );
2853 =head4 C<$sh I<command>> - Force execution of a command in a shell
2855 Like the above, but the command is passed to the shell. Again, we use
2856 C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
2860 # $sh command - start a shell and run a command in it.
2861 if (my ($arg) = $cmd =~ m#\A$sh\s*(.*)#ms) {
2863 # XXX: using csh or tcsh destroys sigint retvals!
2864 #&system($1); # use this instead
2866 # use the user's shell, or Bourne if none defined.
2867 &system( $ENV{SHELL} || "/bin/sh", "-c", $arg );
2871 =head4 C<H> - display commands in history
2873 Prints the contents of C<@hist> (if any).
2877 if ($cmd =~ /\AH\b\s*\*/) {
2878 @hist = @truehist = ();
2879 print $OUT "History cleansed\n";
2884 = $cmd =~ /\AH\b\s*(?:-(\d+))?/) {
2886 # Anything other than negative numbers is ignored by
2887 # the (incorrect) pattern, so this test does nothing.
2888 $end = $num ? ( $#hist - $num ) : 0;
2890 # Set to the minimum if less than zero.
2891 $hist = 0 if $hist < 0;
2893 # Start at the end of the array.
2894 # Stay in while we're still above the ending value.
2895 # Tick back by one each time around the loop.
2896 for ( $i = $#hist ; $i > $end ; $i-- ) {
2898 # Print the command unless it has no arguments.
2899 print $OUT "$i: ", $hist[$i], "\n"
2900 unless $hist[$i] =~ /^.?$/;
2905 =head4 C<man, doc, perldoc> - look up documentation
2907 Just calls C<runman()> to print the appropriate document.
2911 # man, perldoc, doc - show manual pages.
2913 = $cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
2920 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
2921 the bottom of the loop.
2925 my $print_cmd = 'print {$DB::OUT} ';
2926 # p - print (no args): print $_.
2928 $cmd = $print_cmd . '$_';
2931 # p - print the given expression.
2932 $cmd =~ s/\Ap\b/$print_cmd /;
2934 =head4 C<=> - define command alias
2936 Manipulates C<%alias> to add or list command aliases.
2940 # = - set up a command alias.
2941 if ($cmd =~ s/\A=\s*//) {
2943 if ( length $cmd == 0 ) {
2945 # No args, get current aliases.
2946 @keys = sort keys %alias;
2948 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
2950 # Creating a new alias. $k is alias name, $v is
2953 # can't use $_ or kill //g state
2954 for my $x ( $k, $v ) {
2956 # Escape "alarm" characters.
2960 # Substitute key for value, using alarm chars
2961 # as separators (which is why we escaped them in
2963 $alias{$k} = "s\a$k\a$v\a";
2965 # Turn off standard warn and die behavior.
2966 local $SIG{__DIE__};
2967 local $SIG{__WARN__};
2970 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
2972 # Nope. Bad alias. Say so and get out.
2973 print $OUT "Can't alias $k to $v: $@\n";
2978 # We'll only list the new one.
2980 } ## end elsif (my ($k, $v) = ($cmd...
2982 # The argument is the alias to list.
2990 # Messy metaquoting: Trim the substitution code off.
2991 # We use control-G as the delimiter because it's not
2992 # likely to appear in the alias.
2993 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
2996 print $OUT "$k\t= $1\n";
2998 elsif ( defined $alias{$k} ) {
3000 # Couldn't trim it off; just print the alias code.
3001 print $OUT "$k\t$alias{$k}\n";
3006 print "No alias for $k\n";
3008 } ## end for my $k (@keys)
3012 =head4 C<source> - read commands from a file.
3014 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3019 # source - read commands from a file (or pipe!) and execute.
3020 if (my ($sourced_fn) = $cmd =~ /\Asource\s+(.*\S)/) {
3021 if ( open my $fh, $sourced_fn ) {
3023 # Opened OK; stick it in the list of file handles.
3029 &warn("Can't execute '$sourced_fn': $!\n");
3034 if (my ($which_cmd, $position)
3035 = $cmd =~ /^(enable|disable)\s+(\S+)\s*$/) {
3037 my ($fn, $line_num);
3038 if ($position =~ m{\A\d+\z})
3041 $line_num = $position;
3043 elsif (my ($new_fn, $new_line_num)
3044 = $position =~ m{\A(.*):(\d+)\z}) {
3045 ($fn, $line_num) = ($new_fn, $new_line_num);
3049 &warn("Wrong spec for enable/disable argument.\n");
3053 if (_has_breakpoint_data_ref($fn, $line_num)) {
3054 _set_breakpoint_enabled_status($fn, $line_num,
3055 ($which_cmd eq 'enable' ? 1 : '')
3059 &warn("No breakpoint set at ${fn}:${line_num}\n");
3066 =head4 C<save> - send current history to a file
3068 Takes the complete history, (not the shrunken version you see with C<H>),
3069 and saves it to the given filename, so it can be replayed using C<source>.
3071 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3075 # save source - write commands to a file for later use
3076 if (my ($new_fn) = $cmd =~ /\Asave\s*(.*)\z/) {
3077 my $filename = $new_fn || '.perl5dbrc'; # default?
3078 if ( open my $fh, '>', $filename ) {
3080 # chomp to remove extraneous newlines from source'd files
3081 chomp( my @truelist =
3082 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3084 print $fh join( "\n", @truelist );
3085 print "commands saved in $file\n";
3088 &warn("Can't save debugger commands in '$new_fn': $!\n");
3093 =head4 C<R> - restart
3095 Restart the debugger session.
3097 =head4 C<rerun> - rerun the current session
3099 Return to any given position in the B<true>-history list
3103 # R - restart execution.
3104 # rerun - controlled restart execution.
3105 if (my ($cmd_cmd, $cmd_params) =
3106 $cmd =~ /\A((?:R)|(?:rerun\s*(.*)))\z/) {
3107 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
3109 # Close all non-system fds for a clean restart. A more
3110 # correct method would be to close all fds that were not
3111 # open when the process started, but this seems to be
3112 # hard. See "debugger 'R'estart and open database
3113 # connections" on p5p.
3115 my $max_fd = 1024; # default if POSIX can't be loaded
3116 if (eval { require POSIX }) {
3117 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
3120 if (defined $max_fd) {
3121 foreach ($^F+1 .. $max_fd-1) {
3122 next unless open FD_TO_CLOSE, "<&=$_";
3127 # And run Perl again. We use exec() to keep the
3128 # PID stable (and that way $ini_pids is still valid).
3129 exec(@args) || print $OUT "exec failed: $!\n";
3134 =head4 C<|, ||> - pipe output through the pager.
3136 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3137 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3138 pipe to the pager (restoring the output filehandles if this fails). If this
3139 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3140 set C<$signal>, sending us back into the debugger.
3142 We then trim off the pipe symbols and C<redo> the command loop at the
3143 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3148 # || - run command in the pager, with output to DB::OUT.
3149 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
3150 if ( $pager =~ /^\|/ ) {
3152 # Default pager is into a pipe. Redirect I/O.
3153 open( SAVEOUT, ">&STDOUT" )
3154 || &warn("Can't save STDOUT");
3155 open( STDOUT, ">&OUT" )
3156 || &warn("Can't redirect STDOUT");
3157 } ## end if ($pager =~ /^\|/)
3160 # Not into a pipe. STDOUT is safe.
3161 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3164 # Fix up environment to record we have less if so.
3167 unless ( $piped = open( OUT, $pager ) ) {
3169 # Couldn't open pipe to pager.
3170 &warn("Can't pipe output to '$pager'");
3171 if ( $pager =~ /^\|/ ) {
3173 # Redirect I/O back again.
3174 open( OUT, ">&STDOUT" ) # XXX: lost message
3175 || &warn("Can't restore DB::OUT");
3176 open( STDOUT, ">&SAVEOUT" )
3177 || &warn("Can't restore STDOUT");
3179 } ## end if ($pager =~ /^\|/)
3182 # Redirect I/O. STDOUT already safe.
3183 open( OUT, ">&STDOUT" ) # XXX: lost message
3184 || &warn("Can't restore DB::OUT");
3187 } ## end unless ($piped = open(OUT,...
3189 # Set up broken-pipe handler if necessary.
3190 $SIG{PIPE} = \&DB::catch
3192 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
3195 # Save current filehandle, and put it back.
3196 $selected = select(OUT);
3197 # Don't put it back if pager was a pipe.
3198 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
3200 # Trim off the pipe symbols and run the command now.
3201 $cmd =~ s#\A\|+\s*##;
3205 =head3 END OF COMMAND PARSING
3207 Anything left in C<$cmd> at this point is a Perl expression that we want to
3208 evaluate. We'll always evaluate in the user's context, and fully qualify
3209 any variables we might want to address in the C<DB> package.
3213 # t - turn trace on.
3214 if ($cmd =~ s#\At\s+(\d+)?#\$DB::trace |= 1;\n#) {
3216 $trace_to_depth = $trace_arg ? $stack_depth||0 + $1 : 1E9;
3219 # s - single-step. Remember the last command was 's'.
3220 if ($cmd =~ s/\As\s/\$DB::single = 1;\n/) {
3224 # n - single-step, but not into subs. Remember last command
3226 if ($cmd =~ s#\An\s#\$DB::single = 2;\n#) {
3232 # Make sure the flag that says "the debugger's running" is
3233 # still on, to make sure we get control again.
3234 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3236 # Run *our* eval that executes in the caller's context.
3239 # Turn off the one-time-dump stuff now.
3241 $onetimeDump = undef;
3242 $onetimedumpDepth = undef;
3244 elsif ( $term_pid == $$ ) {
3245 eval { # May run under miniperl, when not available...
3250 # XXX If this is the master pid, print a newline.
3253 } ## end while (($term || &setterm...
3255 =head3 POST-COMMAND PROCESSING
3257 After each command, we check to see if the command output was piped anywhere.
3258 If so, we go through the necessary code to unhook the pipe and go back to
3259 our standard filehandles for input and output.
3265 # At the end of every command:
3268 # Unhook the pipe mechanism now.
3269 if ( $pager =~ /^\|/ ) {
3271 # No error from the child.
3274 # we cannot warn here: the handle is missing --tchrist
3275 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
3277 # most of the $? crud was coping with broken cshisms
3278 # $? is explicitly set to 0, so this never runs.
3280 print SAVEOUT "Pager '$pager' failed: ";
3282 print SAVEOUT "shell returned -1\n";
3285 print SAVEOUT ( $? & 127 )
3286 ? " (SIG#" . ( $? & 127 ) . ")"
3287 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3290 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3294 # Reopen filehandle for our output (if we can) and
3295 # restore STDOUT (if we can).
3296 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3297 open( STDOUT, ">&SAVEOUT" )
3298 || &warn("Can't restore STDOUT");
3300 # Turn off pipe exception handler if necessary.
3301 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
3303 # Will stop ignoring SIGPIPE if done like nohup(1)
3304 # does SIGINT but Perl doesn't give us a choice.
3305 } ## end if ($pager =~ /^\|/)
3308 # Non-piped "pager". Just restore STDOUT.
3309 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3312 # Close filehandle pager was using, restore the normal one
3315 select($selected), $selected = "" unless $selected eq "";
3319 } ## end if ($piped)
3322 =head3 COMMAND LOOP TERMINATION
3324 When commands have finished executing, we come here. If the user closed the
3325 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3326 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3327 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3328 The interpreter will then execute the next line and then return control to us
3333 # No more commands? Quit.
3334 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
3336 # Evaluate post-prompt commands.
3337 foreach $evalarg (@$post) {
3340 } # if ($single || $signal)
3342 # Put the user's globals back where you found them.
3343 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3352 my $self = bless {}, $class;
3360 my ($self, $args) = @_;
3362 %{$self} = (%$self, %$args);
3369 foreach my $slot_name (qw(after explicit_stop infix position prefix)) {
3370 my $slot = $slot_name;
3375 ${ $self->{$slot} } = shift;
3378 return ${ $self->{$slot} };
3381 *{"append_to_$slot"} = sub {
3385 return $self->$slot($self->$slot . $s);
3390 sub _DB_on_init__initialize_globals
3394 # Check for whether we should be running continuously or not.
3395 # _After_ the perl program is compiled, $single is set to 1:
3396 if ( $single and not $second_time++ ) {
3398 # Options say run non-stop. Run until we get an interrupt.
3399 if ($runnonstop) { # Disable until signal
3400 # If there's any call stack in place, turn off single
3401 # stepping into subs throughout the stack.
3402 for my $i (0 .. $stack_depth) {
3406 # And we are now no longer in single-step mode.
3409 # If we simply returned at this point, we wouldn't get
3410 # the trace info. Fall on through.
3412 } ## end if ($runnonstop)
3414 elsif ($ImmediateStop) {
3416 # We are supposed to stop here; XXX probably a break.
3417 $ImmediateStop = 0; # We've processed it; turn it off
3418 $signal = 1; # Simulate an interrupt to force
3419 # us into the command loop
3421 } ## end if ($single and not $second_time...
3423 # If we're in single-step mode, or an interrupt (real or fake)
3424 # has occurred, turn off non-stop mode.
3425 $runnonstop = 0 if $single or $signal;
3430 sub _DB__handle_watch_expressions
3435 for my $n (0 .. $#to_watch) {
3436 $evalarg = $to_watch[$n];
3437 local $onetimeDump; # Tell DB::eval() to not output results
3439 # Fix context DB::eval() wants to return an array, but
3440 # we need a scalar here.
3441 my ($val) = join( "', '", DB::eval() );
3442 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
3445 if ( $val ne $old_watch[$n] ) {
3447 # Yep! Show the difference, and fake an interrupt.
3450 Watchpoint $n:\t$to_watch[$n] changed:
3451 old value:\t$old_watch[$n]
3454 $old_watch[$n] = $val;
3455 } ## end if ($val ne $old_watch...
3456 } ## end for my $n (0 ..
3457 } ## end if ($trace & 2)
3462 sub _my_print_lineinfo
3464 my ($self, $i, $incr_pos) = @_;
3467 # Print it indented if tracing is on.
3468 DB::print_lineinfo( ' ' x $stack_depth,
3469 "$i:\t$DB::dbline[$i]" . $self->after );
3472 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3477 return $DB::dbline[$line];
3480 sub _DB__grab_control
3484 # Yes, grab control.
3485 if ($slave_editor) {
3487 # Tell the editor to update its position.
3488 $self->position("\032\032${DB::filename}:$line:0\n");
3489 DB::print_lineinfo($self->position());
3494 Special check: if we're in package C<DB::fake>, we've gone through the
3495 C<END> block at least once. We set up everything so that we can continue
3496 to enter commands and have a valid context to be in.
3500 elsif ( $DB::package eq 'DB::fake' ) {
3502 # Fallen off the end already.
3507 DB::print_help(<<EOP);
3508 Debugged program terminated. Use B<q> to quit or B<R> to restart,
3509 use B<o> I<inhibit_exit> to avoid stopping after program termination,
3510 B<h q>, B<h R> or B<h o> to get additional info.
3513 # Set the DB::eval context appropriately.
3514 $DB::package = 'main';
3515 $DB::usercontext = DB::_calc_usercontext($DB::package);
3516 } ## end elsif ($package eq 'DB::fake')
3520 If the program hasn't finished executing, we scan forward to the
3521 next executable line, print that out, build the prompt from the file and line
3522 number information, and print that.
3529 # Still somewhere in the midst of execution. Set up the
3531 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3532 # Perl 5 ones (sorry, we don't print Klingon
3535 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
3536 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
3537 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
3539 # Break up the prompt if it's really long.
3540 if ( length($self->prefix()) > 30 ) {
3541 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
3543 $self->infix(":\t");
3546 $self->infix("):\t");
3548 $self->prefix . $line. $self->infix
3549 . $self->_curr_line . $self->after
3553 # Print current line info, indenting if necessary.
3554 $self->_my_print_lineinfo($line, $self->position);
3557 my $line_i = sub { return $DB::dbline[$i]; };
3559 # Scan forward, stopping at either the end or the next
3561 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
3564 # Drop out on null statements, block closers, and comments.
3565 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
3567 # Drop out if the user interrupted us.
3570 # Append a newline if the line doesn't have one. Can happen
3571 # in eval'ed text, for instance.
3572 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
3574 # Next executable line.
3575 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
3577 $self->append_to_position($incr_pos);
3578 $self->_my_print_lineinfo($i, $incr_pos);
3579 } ## end for ($i = $line + 1 ; $i...
3580 } ## end else [ if ($slave_editor)
3585 sub _handle_t_command {
3586 if (my ($levels) = $DB::cmd =~ /\At(?:\s+(\d+))?\z/) {
3589 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
3590 print {$OUT} "Trace = "
3592 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3601 sub _handle_S_command {
3602 if (my ($print_all_subs, $should_reverse, $Spatt)
3603 = $DB::cmd =~ /\AS(\s+(!)?(.+))?\z/) {
3604 # $Spatt is the pattern (if any) to use.
3606 my $Srev = defined $should_reverse;
3607 # No args - print all subs.
3608 my $Snocheck = !defined $print_all_subs;
3610 # Need to make these sane here.
3614 # Search through the debugger's magical hash of subs.
3615 # If $nocheck is true, just print the sub name.
3616 # Otherwise, check it against the pattern. We then use
3617 # the XOR trick to reverse the condition as required.
3618 foreach $subname ( sort( keys %sub ) ) {
3619 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
3620 print $OUT $subname, "\n";
3629 sub _handle_V_command_and_X_command {
3631 $DB::cmd =~ s/^X\b/V $DB::package/;
3633 # Bare V commands get the currently-being-debugged package
3635 if ($DB::cmd eq "V") {
3636 $DB::cmd = "V $DB::package";
3639 # V - show variables in package.
3640 if (my ($new_packname, $new_vars_str) =
3641 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
3643 # Save the currently selected filehandle and
3644 # force output to debugger's filehandle (dumpvar
3645 # just does "print" for output).
3646 my $savout = select($OUT);
3648 # Grab package name and variables to dump.
3649 $packname = $new_packname;
3650 my @vars = split( ' ', $new_vars_str );
3652 # If main::dumpvar isn't here, get it.
3653 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
3654 if ( defined &main::dumpvar ) {
3656 # We got it. Turn off subroutine entry/exit messages
3657 # for the moment, along with return values.
3661 # must detect sigpipe failures - not catching
3662 # then will cause the debugger to die.
3666 defined $option{dumpDepth}
3667 ? $option{dumpDepth}
3668 : -1, # assume -1 unless specified
3673 # The die doesn't need to include the $@, because
3674 # it will automatically get propagated for us.
3676 die unless $@ =~ /dumpvar print failed/;
3678 } ## end if (defined &main::dumpvar)
3681 # Couldn't load dumpvar.
3682 print $OUT "dumpvar.pl not available.\n";
3685 # Restore the output filehandle, and go round again.
3693 sub _handle_dash_command {
3695 if ($DB::cmd eq '-') {
3697 # back up by a window; go to 1 if back too far.
3698 $start -= $incr + $window + 1;
3699 $start = 1 if $start <= 0;
3700 $incr = $window - 1;
3702 # Generate and execute a "l +" command (handled below).
3703 $DB::cmd = 'l ' . ($start) . '+';
3710 # The following code may be executed now:
3715 C<sub> is called whenever a subroutine call happens in the program being
3716 debugged. The variable C<$DB::sub> contains the name of the subroutine
3719 The core function of this subroutine is to actually call the sub in the proper
3720 context, capturing its output. This of course causes C<DB::DB> to get called
3721 again, repeating until the subroutine ends and returns control to C<DB::sub>
3722 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3723 return value, and returns its captured copy of the return value as its own
3724 return value. The value then feeds back into the program being debugged as if
3725 C<DB::sub> hadn't been there at all.
3727 C<sub> does all the work of printing the subroutine entry and exit messages
3728 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3729 and also prints the return value if needed (for the C<r> command and if
3730 the 16 bit is set in C<$frame>).
3732 It also tracks the subroutine call depth by saving the current setting of
3733 C<$single> in the C<@stack> package global; if this exceeds the value in
3734 C<$deep>, C<sub> automatically turns on printing of the current depth by
3735 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
3736 of stop/don't stop on entry to subs set as it currently is set.
3738 =head3 C<caller()> support
3740 If C<caller()> is called from the package C<DB>, it provides some
3741 additional data, in the following order:
3747 The package name the sub was in
3749 =item * C<$filename>
3751 The filename it was defined in
3755 The line number it was defined on
3757 =item * C<$subroutine>
3759 The subroutine name; C<(eval)> if an C<eval>().
3763 1 if it has arguments, 0 if not
3765 =item * C<$wantarray>
3767 1 if array context, 0 if scalar context
3769 =item * C<$evaltext>
3771 The C<eval>() text, if any (undefined for C<eval BLOCK>)
3773 =item * C<$is_require>
3775 frame was created by a C<use> or C<require> statement
3779 pragma information; subject to change between versions
3783 pragma information; subject to change between versions
3785 =item * C<@DB::args>
3787 arguments with which the subroutine was invoked
3795 # We need to fully qualify the name ("DB::sub") to make "use strict;"
3796 # happy. -- Shlomi Fish
3798 # Do not use a regex in this subroutine -> results in corrupted memory
3799 # See: [perl #66110]
3801 # lock ourselves under threads
3804 # Whether or not the autoloader was running, a scalar to put the
3805 # sub's return value in (if needed), and an array to put the sub's
3806 # return value in (if needed).
3807 my ( $al, $ret, @ret ) = "";
3808 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) {
3809 print "creating new thread\n";
3812 # If the last ten characters are '::AUTOLOAD', note we've traced
3813 # into AUTOLOAD for $sub.
3814 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3816 $al = " for $$sub" if defined $$sub;
3819 # We stack the stack pointer and then increment it to protect us
3820 # from a situation that might unwind a whole bunch of call frames
3821 # at once. Localizing the stack pointer means that it will automatically
3822 # unwind the same amount when multiple stack frames are unwound.
3823 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3826 $#stack = $stack_depth;
3828 # Save current single-step setting.
3829 $stack[-1] = $single;
3831 # Turn off all flags except single-stepping.
3834 # If we've gotten really deeply recursed, turn on the flag that will
3835 # make us stop with the 'deep recursion' message.
3836 $single |= 4 if $stack_depth == $deep;
3838 # If frame messages are on ...
3840 $frame & 4 # Extended frame entry message
3842 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3844 # Why -1? But it works! :-(
3845 # Because print_trace will call add 1 to it and then call
3846 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3848 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3850 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3852 # standard frame entry message
3856 # Determine the sub's return type, and capture appropriately.
3859 # Called in array context. call sub and capture output.
3860 # DB::DB will recursively get control again if appropriate; we'll come
3861 # back here when the sub is finished.
3867 # Pop the single-step value back off the stack.
3868 $single |= $stack[ $stack_depth-- ];
3870 # Check for exit trace messages...
3872 $frame & 4 # Extended exit message
3874 print_lineinfo( ' ' x $stack_depth, "out " ),
3875 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3877 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3879 # Standard exit message
3883 # Print the return info if we need to.
3884 if ( $doret eq $stack_depth or $frame & 16 ) {
3886 # Turn off output record separator.
3888 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3890 # Indent if we're printing because of $frame tracing.
3891 print $fh ' ' x $stack_depth if $frame & 16;
3893 # Print the return value.
3894 print $fh "list context return from $sub:\n";
3895 dumpit( $fh, \@ret );
3897 # And don't print it again.
3899 } ## end if ($doret eq $stack_depth...
3900 # And we have to return the return value now.
3902 } ## end if (wantarray)
3906 if ( defined wantarray ) {
3908 # Save the value if it's wanted at all.
3913 # Void return, explicitly.
3918 # Pop the single-step value off the stack.
3919 $single |= $stack[ $stack_depth-- ];
3921 # If we're doing exit messages...
3923 $frame & 4 # Extended messages
3925 print_lineinfo( ' ' x $stack_depth, "out " ),
3926 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3928 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3934 # If we are supposed to show the return value... same as before.
3935 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
3937 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3938 print $fh ( ' ' x $stack_depth ) if $frame & 16;
3941 ? "scalar context return from $sub: "
3942 : "void context return from $sub\n"
3944 dumpit( $fh, $ret ) if defined wantarray;
3946 } ## end if ($doret eq $stack_depth...
3948 # Return the appropriate scalar value.
3950 } ## end else [ if (wantarray)
3957 # lock ourselves under threads
3960 # Whether or not the autoloader was running, a scalar to put the
3961 # sub's return value in (if needed), and an array to put the sub's
3962 # return value in (if needed).
3963 my ( $al, $ret, @ret ) = "";
3964 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
3965 print "creating new thread\n";
3968 # If the last ten characters are C'::AUTOLOAD', note we've traced
3969 # into AUTOLOAD for $sub.
3970 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3974 # We stack the stack pointer and then increment it to protect us
3975 # from a situation that might unwind a whole bunch of call frames
3976 # at once. Localizing the stack pointer means that it will automatically
3977 # unwind the same amount when multiple stack frames are unwound.
3978 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3981 $#stack = $stack_depth;
3983 # Save current single-step setting.
3984 $stack[-1] = $single;
3986 # Turn off all flags except single-stepping.
3989 # If we've gotten really deeply recursed, turn on the flag that will
3990 # make us stop with the 'deep recursion' message.
3991 $single |= 4 if $stack_depth == $deep;
3993 # If frame messages are on ...
3995 $frame & 4 # Extended frame entry message
3997 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3999 # Why -1? But it works! :-(
4000 # Because print_trace will call add 1 to it and then call
4001 # dump_trace; this results in our skipping -1+1 = 0 stack frames
4003 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
4005 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
4007 # standard frame entry message
4011 # Pop the single-step value back off the stack.
4012 $single |= $stack[ $stack_depth-- ];
4014 # call the original lvalue sub.
4018 # Abstracting common code from multiple places elsewhere:
4019 sub depth_print_lineinfo {
4020 my $always_print = shift;
4022 print_lineinfo( @_ ) if ($always_print or $stack_depth < $trace_to_depth);
4025 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
4027 In Perl 5.8.0, there was a major realignment of the commands and what they did,
4028 Most of the changes were to systematize the command structure and to eliminate
4029 commands that threw away user input without checking.
4031 The following sections describe the code added to make it easy to support
4032 multiple command sets with conflicting command names. This section is a start
4033 at unifying all command processing to make it simpler to develop commands.
4035 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
4036 number, and C<$dbline> (the current line) as arguments.
4038 Support functions in this section which have multiple modes of failure C<die>
4039 on error; the rest simply return a false value.
4041 The user-interface functions (all of the C<cmd_*> functions) just output
4046 The C<%set> hash defines the mapping from command letter to subroutine
4049 C<%set> is a two-level hash, indexed by set name and then by command name.
4050 Note that trying to set the CommandSet to C<foobar> simply results in the
4051 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
4060 'A' => 'pre580_null',
4062 'B' => 'pre580_null',
4063 'd' => 'pre580_null',
4066 'M' => 'pre580_null',
4068 'o' => 'pre580_null',
4074 '<' => 'pre590_prepost',
4075 '<<' => 'pre590_prepost',
4076 '>' => 'pre590_prepost',
4077 '>>' => 'pre590_prepost',
4078 '{' => 'pre590_prepost',
4079 '{{' => 'pre590_prepost',
4083 my %breakpoints_data;
4085 sub _has_breakpoint_data_ref {
4086 my ($filename, $line) = @_;
4089 exists( $breakpoints_data{$filename} )
4091 exists( $breakpoints_data{$filename}{$line} )
4095 sub _get_breakpoint_data_ref {
4096 my ($filename, $line) = @_;
4098 return ($breakpoints_data{$filename}{$line} ||= +{});
4101 sub _delete_breakpoint_data_ref {
4102 my ($filename, $line) = @_;
4104 delete($breakpoints_data{$filename}{$line});
4105 if (! scalar(keys( %{$breakpoints_data{$filename}} )) ) {
4106 delete($breakpoints_data{$filename});
4112 sub _set_breakpoint_enabled_status {
4113 my ($filename, $line, $status) = @_;
4115 _get_breakpoint_data_ref($filename, $line)->{'enabled'} =
4122 sub _enable_breakpoint_temp_enabled_status {
4123 my ($filename, $line) = @_;
4125 _get_breakpoint_data_ref($filename, $line)->{'temp_enabled'} = 1;
4130 sub _cancel_breakpoint_temp_enabled_status {
4131 my ($filename, $line) = @_;
4133 my $ref = _get_breakpoint_data_ref($filename, $line);
4135 delete ($ref->{'temp_enabled'});
4138 _delete_breakpoint_data_ref($filename, $line);
4144 sub _is_breakpoint_enabled {
4145 my ($filename, $line) = @_;
4147 my $data_ref = _get_breakpoint_data_ref($filename, $line);
4148 return ($data_ref->{'enabled'} || $data_ref->{'temp_enabled'});
4151 =head2 C<cmd_wrapper()> (API)
4153 C<cmd_wrapper()> allows the debugger to switch command sets
4154 depending on the value of the C<CommandSet> option.
4156 It tries to look up the command in the C<%set> package-level I<lexical>
4157 (which means external entities can't fiddle with it) and create the name of
4158 the sub to call based on the value found in the hash (if it's there). I<All>
4159 of the commands to be handled in a set have to be added to C<%set>; if they
4160 aren't found, the 5.8.0 equivalent is called (if there is one).
4162 This code uses symbolic references.
4169 my $dblineno = shift;
4171 # Assemble the command subroutine's name by looking up the
4172 # command set and command name in %set. If we can't find it,
4173 # default to the older version of the command.
4175 . ( $set{$CommandSet}{$cmd}
4176 || ( $cmd =~ /^[<>{]+/o ? 'prepost' : $cmd ) );
4178 # Call the command subroutine, call it by name.
4179 return __PACKAGE__->can($call)->( $cmd, $line, $dblineno );
4180 } ## end sub cmd_wrapper
4182 =head3 C<cmd_a> (command)
4184 The C<a> command handles pre-execution actions. These are associated with a
4185 particular line, so they're stored in C<%dbline>. We default to the current
4186 line if none is specified.
4192 my $line = shift || ''; # [.|line] expr
4195 # If it's dot (here), or not all digits, use the current line.
4196 $line =~ s/\A\./$dbline/;
4198 # Should be a line number followed by an expression.
4199 if ( my ($lineno, $expr) = $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
4201 if (! length($lineno)) {
4205 # If we have an expression ...
4206 if ( length $expr ) {
4208 # ... but the line isn't breakable, complain.
4209 if ( $dbline[$lineno] == 0 ) {
4211 "Line $lineno($dbline[$lineno]) does not have an action?\n";
4215 # It's executable. Record that the line has an action.
4216 $had_breakpoints{$filename} |= 2;
4218 # Remove any action, temp breakpoint, etc.
4219 $dbline{$lineno} =~ s/\0[^\0]*//;
4221 # Add the action to the line.
4222 $dbline{$lineno} .= "\0" . action($expr);
4224 _set_breakpoint_enabled_status($filename, $lineno, 1);
4226 } ## end if (length $expr)
4227 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
4232 "Adding an action requires an optional lineno and an expression\n"
4237 =head3 C<cmd_A> (command)
4239 Delete actions. Similar to above, except the delete code is in a separate
4240 subroutine, C<delete_action>.
4246 my $line = shift || '';
4250 $line =~ s/^\./$dbline/;
4252 # Call delete_action with a null param to delete them all.
4253 # The '1' forces the eval to be true. It'll be false only
4254 # if delete_action blows up for some reason, in which case
4255 # we print $@ and get out.
4256 if ( $line eq '*' ) {
4257 if (! eval { _delete_all_actions(); 1 }) {
4263 # There's a real line number. Pass it to delete_action.
4264 # Error trapping is as above.
4265 elsif ( $line =~ /^(\S.*)/ ) {
4266 if (! eval { delete_action($1); 1 }) {
4272 # Swing and a miss. Bad syntax.
4275 "Deleting an action requires a line number, or '*' for all\n" ; # hint
4279 =head3 C<delete_action> (API)
4281 C<delete_action> accepts either a line number or C<undef>. If a line number
4282 is specified, we check for the line being executable (if it's not, it
4283 couldn't have had an action). If it is, we just take the action off (this
4284 will get any kind of an action, including breakpoints).
4288 sub _remove_action_from_dbline {
4291 $dbline{$i} =~ s/\0[^\0]*//; # \^a
4292 delete $dbline{$i} if $dbline{$i} eq '';
4297 sub _delete_all_actions {
4298 print {$OUT} "Deleting all actions...\n";
4300 for my $file ( keys %had_breakpoints ) {
4301 local *dbline = $main::{ '_<' . $file };
4304 for my $i (1 .. $max) {
4305 if ( defined $dbline{$i} ) {
4306 _remove_action_from_dbline($i);
4310 unless ( $had_breakpoints{$file} &= ~2 ) {
4311 delete $had_breakpoints{$file};
4321 if ( defined($i) ) {
4323 die "Line $i has no action .\n" if $dbline[$i] == 0;
4325 # Nuke whatever's there.
4326 _remove_action_from_dbline($i);
4329 _delete_all_actions();
4333 =head3 C<cmd_b> (command)
4335 Set breakpoints. Since breakpoints can be set in so many places, in so many
4336 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4337 we try to parse the command type, and then shuttle it off to an appropriate
4338 subroutine to actually do the work of setting the breakpoint in the right
4345 my $line = shift; # [.|line] [cond]
4348 my $default_cond = sub {
4350 return length($cond) ? $cond : '1';
4353 # Make . the current line number if it's there..
4354 $line =~ s/^\.(\s|\z)/$dbline$1/;
4356 # No line number, no condition. Simple break on current line.
4357 if ( $line =~ /^\s*$/ ) {
4358 cmd_b_line( $dbline, 1 );
4361 # Break on load for a file.
4362 elsif ( my ($file) = $line =~ /^load\b\s*(.*)/ ) {
4367 # b compile|postpone <some sub> [<condition>]
4368 # The interpreter actually traps this one for us; we just put the
4369 # necessary condition in the %postponed hash.
4370 elsif ( my ($action, $subname, $cond)
4371 = $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4373 # De-Perl4-ify the name - ' separators to ::.
4374 $subname =~ s/'/::/g;
4376 # Qualify it into the current package unless it's already qualified.
4377 $subname = "${package}::" . $subname unless $subname =~ /::/;
4379 # Add main if it starts with ::.
4380 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4382 # Save the break type for this sub.
4383 $postponed{$subname} = (($action eq 'postpone')
4384 ? ( "break +0 if " . $default_cond->($cond) )
4386 } ## end elsif ($line =~ ...
4387 # b <filename>:<line> [<condition>]
4388 elsif (my ($filename, $line_num, $cond)
4389 = $line =~ /\A(\S+[^:]):(\d+)\s*(.*)/ms) {
4390 cmd_b_filename_line(
4393 (length($cond) ? $cond : '1'),
4396 # b <sub name> [<condition>]
4397 elsif ( my ($new_subname, $new_cond) =
4398 $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4401 $subname = $new_subname;
4402 cmd_b_sub( $subname, $default_cond->($new_cond) );
4405 # b <line> [<condition>].
4406 elsif ( my ($line_n, $cond) = $line =~ /^(\d*)\s*(.*)/ ) {
4408 # Capture the line. If none, it's the current line.
4409 $line = $line_n || $dbline;
4412 cmd_b_line( $line, $default_cond->($cond) );
4415 # Line didn't make sense.
4417 print "confused by line($line)?\n";
4423 =head3 C<break_on_load> (API)
4425 We want to break when this file is loaded. Mark this file in the
4426 C<%break_on_load> hash, and note that it has a breakpoint in
4427 C<%had_breakpoints>.
4433 $break_on_load{$file} = 1;
4434 $had_breakpoints{$file} |= 1;
4437 =head3 C<report_break_on_load> (API)
4439 Gives us an array of filenames that are set to break on load. Note that
4440 only files with break-on-load are in here, so simply showing the keys
4445 sub report_break_on_load {
4446 sort keys %break_on_load;
4449 =head3 C<cmd_b_load> (command)
4451 We take the file passed in and try to find it in C<%INC> (which maps modules
4452 to files they came from). We mark those files for break-on-load via
4453 C<break_on_load> and then report that it was done.
4461 # This is a block because that way we can use a redo inside it
4462 # even without there being any looping structure at all outside it.
4465 # Save short name and full path if found.
4467 push @files, $::INC{$file} if $::INC{$file};
4469 # Tack on .pm and do it again unless there was a '.' in the name
4471 $file .= '.pm', redo unless $file =~ /\./;
4474 # Do the real work here.
4475 break_on_load($_) for @files;
4477 # All the files that have break-on-load breakpoints.
4478 @files = report_break_on_load;
4480 # Normalize for the purposes of our printing this.
4483 print $OUT "Will stop on load of '@files'.\n";
4484 } ## end sub cmd_b_load
4486 =head3 C<$filename_error> (API package global)
4488 Several of the functions we need to implement in the API need to work both
4489 on the current file and on other files. We don't want to duplicate code, so
4490 C<$filename_error> is used to contain the name of the file that's being
4491 worked on (if it's not the current one).
4493 We can now build functions in pairs: the basic function works on the current
4494 file, and uses C<$filename_error> as part of its error message. Since this is
4495 initialized to C<"">, no filename will appear when we are working on the
4498 The second function is a wrapper which does the following:
4504 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4508 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4512 Calls the first function.
4514 The first function works on the I<current> file (i.e., the one we changed to),
4515 and prints C<$filename_error> in the error message (the name of the other file)
4516 if it needs to. When the functions return, C<*dbline> is restored to point
4517 to the actual current file (the one we're executing in) and
4518 C<$filename_error> is restored to C<"">. This restores everything to
4519 the way it was before the second function was called at all.
4521 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4528 use vars qw($filename_error);
4529 $filename_error = '';
4531 =head3 breakable_line(from, to) (API)
4533 The subroutine decides whether or not a line in the current file is breakable.
4534 It walks through C<@dbline> within the range of lines specified, looking for
4535 the first line that is breakable.
4537 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4538 first line I<after> C<$to> that's breakable, if there is one.
4540 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4541 first line I<before> C<$to> that's breakable, if there is one.
4545 sub breakable_line {
4547 my ( $from, $to ) = @_;
4549 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4552 # If there are at least 2 arguments, we're trying to search a range.
4555 # $delta is positive for a forward search, negative for a backward one.
4556 my $delta = $from < $to ? +1 : -1;
4558 # Keep us from running off the ends of the file.
4559 my $limit = $delta > 0 ? $#dbline : 1;
4561 # Clever test. If you're a mathematician, it's obvious why this
4562 # test works. If not:
4563 # If $delta is positive (going forward), $limit will be $#dbline.
4564 # If $to is less than $limit, ($limit - $to) will be positive, times
4565 # $delta of 1 (positive), so the result is > 0 and we should use $to
4566 # as the stopping point.
4568 # If $to is greater than $limit, ($limit - $to) is negative,
4569 # times $delta of 1 (positive), so the result is < 0 and we should
4570 # use $limit ($#dbline) as the stopping point.
4572 # If $delta is negative (going backward), $limit will be 1.
4573 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4574 # (negative) so the result is > 0, and we use $to as the stopping
4577 # If $to is less than zero, ($limit - $to) will be positive,
4578 # times $delta of -1 (negative), so the result is not > 0, and
4579 # we use $limit (1) as the stopping point.
4581 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4582 # (negative), still giving zero; the result is not > 0, and
4583 # we use $limit (1) as the stopping point.
4585 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4586 # (negative), giving a positive (>0) value, so we'll set $limit to
4589 $limit = $to if ( $limit - $to ) * $delta > 0;
4591 # The real search loop.
4592 # $i starts at $from (the point we want to start searching from).
4593 # We move through @dbline in the appropriate direction (determined
4594 # by $delta: either -1 (back) or +1 (ahead).
4595 # We stay in as long as we haven't hit an executable line
4596 # ($dbline[$i] == 0 means not executable) and we haven't reached
4597 # the limit yet (test similar to the above).
4598 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4600 } ## end if (@_ >= 2)
4602 # If $i points to a line that is executable, return that.
4603 return $i unless $dbline[$i] == 0;
4605 # Format the message and print it: no breakable lines in range.
4606 my ( $pl, $upto ) = ( '', '' );
4607 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4609 # If there's a filename in filename_error, we'll see it.
4611 die "Line$pl $from$upto$filename_error not breakable\n";
4612 } ## end sub breakable_line
4614 =head3 breakable_line_in_filename(file, from, to) (API)
4616 Like C<breakable_line>, but look in another file.
4620 sub breakable_line_in_filename {
4622 # Capture the file name.
4625 # Swap the magic line array over there temporarily.
4626 local *dbline = $main::{ '_<' . $f };
4628 # If there's an error, it's in this other file.
4629 local $filename_error = " of '$f'";
4631 # Find the breakable line.
4634 # *dbline and $filename_error get restored when this block ends.
4636 } ## end sub breakable_line_in_filename
4638 =head3 break_on_line(lineno, [condition]) (API)
4640 Adds a breakpoint with the specified condition (or 1 if no condition was
4641 specified) to the specified line. Dies if it can't.
4647 my $cond = @_ ? shift(@_) : 1;
4653 # Woops, not a breakable line. $filename_error allows us to say
4654 # if it was in a different file.
4655 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4657 # Mark this file as having breakpoints in it.
4658 $had_breakpoints{$filename} |= 1;
4660 # If there is an action or condition here already ...
4661 if ( $dbline{$i} ) {
4663 # ... swap this condition for the existing one.
4664 $dbline{$i} =~ s/^[^\0]*/$cond/;
4668 # Nothing here - just add the condition.
4669 $dbline{$i} = $cond;
4671 _set_breakpoint_enabled_status($filename, $i, 1);
4675 } ## end sub break_on_line
4677 =head3 cmd_b_line(line, [condition]) (command)
4679 Wrapper for C<break_on_line>. Prints the failure message if it
4685 if (not eval { break_on_line(@_); 1 }) {
4687 print $OUT $@ and return;
4691 } ## end sub cmd_b_line
4693 =head3 cmd_b_filename_line(line, [condition]) (command)
4695 Wrapper for C<break_on_filename_line>. Prints the failure message if it
4700 sub cmd_b_filename_line {
4701 if (not eval { break_on_filename_line(@_); 1 }) {
4703 print $OUT $@ and return;
4709 =head3 break_on_filename_line(file, line, [condition]) (API)
4711 Switches to the file specified and then calls C<break_on_line> to set
4716 sub break_on_filename_line {
4719 my $cond = @_ ? shift(@_) : 1;
4721 # Switch the magical hash temporarily.
4722 local *dbline = $main::{ '_<' . $f };
4724 # Localize the variables that break_on_line uses to make its message.
4725 local $filename_error = " of '$f'";
4726 local $filename = $f;
4728 # Add the breakpoint.
4729 break_on_line( $i, $cond );
4732 } ## end sub break_on_filename_line
4734 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4736 Switch to another file, search the range of lines specified for an
4737 executable one, and put a breakpoint on the first one you find.
4741 sub break_on_filename_line_range {
4745 my $cond = @_ ? shift(@_) : 1;
4747 # Find a breakable line if there is one.
4748 my $i = breakable_line_in_filename( $f, $from, $to );
4750 # Add the breakpoint.
4751 break_on_filename_line( $f, $i, $cond );
4754 } ## end sub break_on_filename_line_range
4756 =head3 subroutine_filename_lines(subname, [condition]) (API)
4758 Search for a subroutine within a given file. The condition is ignored.
4759 Uses C<find_sub> to locate the desired subroutine.
4763 sub subroutine_filename_lines {
4764 my ( $subname ) = @_;
4766 # Returned value from find_sub() is fullpathname:startline-endline.
4767 # The match creates the list (fullpathname, start, end).
4768 return (find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/);
4769 } ## end sub subroutine_filename_lines
4771 =head3 break_subroutine(subname) (API)
4773 Places a break on the first line possible in the specified subroutine. Uses
4774 C<subroutine_filename_lines> to find the subroutine, and
4775 C<break_on_filename_line_range> to place the break.
4779 sub break_subroutine {
4780 my $subname = shift;
4782 # Get filename, start, and end.
4783 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
4784 or die "Subroutine $subname not found.\n";
4787 # Null condition changes to '1' (always true).
4788 my $cond = @_ ? shift(@_) : 1;
4790 # Put a break the first place possible in the range of lines
4791 # that make up this subroutine.
4792 break_on_filename_line_range( $file, $s, $e, $cond );
4795 } ## end sub break_subroutine
4797 =head3 cmd_b_sub(subname, [condition]) (command)
4799 We take the incoming subroutine name and fully-qualify it as best we can.
4803 =item 1. If it's already fully-qualified, leave it alone.
4805 =item 2. Try putting it in the current package.
4807 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
4809 =item 4. If it starts with '::', put it in 'main::'.
4813 After all this cleanup, we call C<break_subroutine> to try to set the
4819 my ( $subname, $cond ) = @_;
4821 # Add always-true condition if we have none.
4822 $cond = 1 unless @_ >= 2;
4824 # If the subname isn't a code reference, qualify it so that
4825 # break_subroutine() will work right.
4826 unless ( ref $subname eq 'CODE' ) {
4829 $subname =~ s/\'/::/g;
4832 # Put it in this package unless it's already qualified.
4833 $subname = "${package}::" . $subname
4834 unless $subname =~ /::/;
4836 # Requalify it into CORE::GLOBAL if qualifying it into this
4837 # package resulted in its not being defined, but only do so
4838 # if it really is in CORE::GLOBAL.
4839 $subname = "CORE::GLOBAL::$s"
4840 if not defined &$subname
4842 and defined &{"CORE::GLOBAL::$s"};
4844 # Put it in package 'main' if it has a leading ::.
4845 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4847 } ## end unless (ref $subname eq 'CODE')
4849 # Try to set the breakpoint.
4850 if (not eval { break_subroutine( $subname, $cond ); 1 }) {
4852 print $OUT $@ and return;
4856 } ## end sub cmd_b_sub
4858 =head3 C<cmd_B> - delete breakpoint(s) (command)
4860 The command mostly parses the command line and tries to turn the argument
4861 into a line spec. If it can't, it uses the current line. It then calls
4862 C<delete_breakpoint> to actually do the work.
4864 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
4865 thereby deleting all the breakpoints.
4872 # No line spec? Use dbline.
4873 # If there is one, use it if it's non-zero, or wipe it out if it is.
4874 my $line = ( $_[0] =~ /\A\./ ) ? $dbline : (shift || '');
4877 # If the line was dot, make the line the current one.
4878 $line =~ s/^\./$dbline/;
4880 # If it's * we're deleting all the breakpoints.
4881 if ( $line eq '*' ) {
4882 if (not eval { delete_breakpoint(); 1 }) {
4887 # If there is a line spec, delete the breakpoint on that line.
4888 elsif ( $line =~ /\A(\S.*)/ ) {
4889 if (not eval { delete_breakpoint( $line || $dbline ); 1 }) {
4893 } ## end elsif ($line =~ /^(\S.*)/)
4898 "Deleting a breakpoint requires a line number, or '*' for all\n"
4905 =head3 delete_breakpoint([line]) (API)
4907 This actually does the work of deleting either a single breakpoint, or all
4910 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
4911 just drop out with a message saying so. If it is, we remove the condition
4912 part of the 'condition\0action' that says there's a breakpoint here. If,
4913 after we've done that, there's nothing left, we delete the corresponding
4914 line in C<%dbline> to signal that no action needs to be taken for this line.
4916 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
4917 which lists all currently-loaded files which have breakpoints. We then look
4918 at each line in each of these files, temporarily switching the C<%dbline>
4919 and C<@dbline> structures to point to the files in question, and do what
4920 we did in the single line case: delete the condition in C<@dbline>, and
4921 delete the key in C<%dbline> if nothing's left.
4923 We then wholesale delete C<%postponed>, C<%postponed_file>, and
4924 C<%break_on_load>, because these structures contain breakpoints for files
4925 and code that haven't been loaded yet. We can just kill these off because there
4926 are no magical debugger structures associated with them.
4930 sub _remove_breakpoint_entry {
4934 _delete_breakpoint_data_ref($fn, $i);
4939 sub _delete_all_breakpoints {
4940 print {$OUT} "Deleting all breakpoints...\n";
4942 # %had_breakpoints lists every file that had at least one
4944 for my $fn ( keys %had_breakpoints ) {
4946 # Switch to the desired file temporarily.
4947 local *dbline = $main::{ '_<' . $fn };
4951 # For all lines in this file ...
4952 for my $i (1 .. $max) {
4954 # If there's a breakpoint or action on this line ...
4955 if ( defined $dbline{$i} ) {
4957 # ... remove the breakpoint.
4958 $dbline{$i} =~ s/\A[^\0]+//;
4959 if ( $dbline{$i} =~ s/\A\0?\z// ) {
4960 # Remove the entry altogether if no action is there.
4961 _remove_breakpoint_entry($fn, $i);
4963 } ## end if (defined $dbline{$i...
4964 } ## end for $i (1 .. $max)
4966 # If, after we turn off the "there were breakpoints in this file"
4967 # bit, the entry in %had_breakpoints for this file is zero,
4968 # we should remove this file from the hash.
4969 if ( not $had_breakpoints{$fn} &= (~1) ) {
4970 delete $had_breakpoints{$fn};
4972 } ## end for my $fn (keys %had_breakpoints)
4974 # Kill off all the other breakpoints that are waiting for files that
4975 # haven't been loaded yet.
4977 undef %postponed_file;
4978 undef %break_on_load;
4983 sub _delete_breakpoint_from_line {
4986 # Woops. This line wasn't breakable at all.
4987 die "Line $i not breakable.\n" if $dbline[$i] == 0;
4989 # Kill the condition, but leave any action.
4990 $dbline{$i} =~ s/\A[^\0]*//;
4992 # Remove the entry entirely if there's no action left.
4993 if ($dbline{$i} eq '') {
4994 _remove_breakpoint_entry($filename, $i);
5000 sub delete_breakpoint {
5003 # If we got a line, delete just that one.
5004 if ( defined($i) ) {
5005 _delete_breakpoint_from_line($i);
5007 # No line; delete them all.
5009 _delete_all_breakpoints();
5015 =head3 cmd_stop (command)
5017 This is meant to be part of the new command API, but it isn't called or used
5018 anywhere else in the debugger. XXX It is probably meant for use in development
5023 sub cmd_stop { # As on ^C, but not signal-safy.
5027 =head3 C<cmd_e> - threads
5029 Display the current thread id:
5033 This could be how (when implemented) to send commands to this thread id (e cmd)
5034 or that thread id (e tid cmd).
5041 unless (exists($INC{'threads.pm'})) {
5042 print "threads not loaded($ENV{PERL5DB_THREADED})
5043 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5045 my $tid = threads->tid;
5046 print "thread id: $tid\n";
5050 =head3 C<cmd_E> - list of thread ids
5052 Display the list of available thread ids:
5056 This could be used (when implemented) to send commands to all threads (E cmd).
5063 unless (exists($INC{'threads.pm'})) {
5064 print "threads not loaded($ENV{PERL5DB_THREADED})
5065 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5067 my $tid = threads->tid;
5068 print "thread ids: ".join(', ',
5069 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
5074 =head3 C<cmd_h> - help command (command)
5076 Does the work of either
5082 Showing all the debugger help
5086 Showing help for a specific command
5093 use vars qw($summary);
5098 # If we have no operand, assume null.
5099 my $line = shift || '';
5101 # 'h h'. Print the long-format help.
5102 if ( $line =~ /\Ah\s*\z/ ) {
5106 # 'h <something>'. Search for the command and print only its help.
5107 elsif ( my ($asked) = $line =~ /\A(\S.*)\z/ ) {
5109 # support long commands; otherwise bogus errors
5110 # happen when you ask for h on <CR> for example
5111 my $qasked = quotemeta($asked); # for searching; we don't
5112 # want to use it as a pattern.
5113 # XXX: finds CR but not <CR>
5115 # Search the help string for the command.
5117 $help =~ /^ # Start of a line
5119 (?:[IB]<) # Optional markup
5120 $qasked # The requested command
5125 # It's there; pull it out and print it.
5129 (?:[IB]<) # Optional markup
5130 $qasked # The command
5131 ([\s\S]*?) # Description line(s)
5132 \n) # End of last description line
5133 (?!\s) # Next line not starting with
5142 # Not found; not a debugger command.
5144 print_help("B<$asked> is not a debugger command.\n");
5146 } ## end elsif ($line =~ /^(\S.*)$/)
5148 # 'h' - print the summary help.
5150 print_help($summary);
5154 =head3 C<cmd_i> - inheritance display
5156 Display the (nested) parentage of the module or object given.
5163 foreach my $isa ( split( /\s+/, $line ) ) {
5165 ($isa) = DB::eval();
5172 defined( ${"$_\::VERSION"} )
5173 ? ' ' . ${"$_\::VERSION"}
5175 } @{mro::get_linear_isa(ref($isa) || $isa)}
5181 =head3 C<cmd_l> - list lines (command)
5183 Most of the command is taken up with transforming all the different line
5184 specification syntaxes into 'start-stop'. After that is done, the command
5185 runs a loop over C<@dbline> for the specified range of lines. It handles
5186 the printing of each line and any markers (C<==E<gt>> for current line,
5187 C<b> for break on this line, C<a> for action on this line, C<:> for this
5190 We save the last line listed in the C<$start> global for further listing
5196 my $current_line = $line;
5200 # If this is '-something', delete any spaces after the dash.
5201 $line =~ s/^-\s*$/-/;
5203 # If the line is '$something', assume this is a scalar containing a
5205 if ( $line =~ /^(\$.*)/s ) {
5207 # Set up for DB::eval() - evaluate in *user* context.
5210 my ($s) = DB::eval();
5212 # Ooops. Bad scalar.
5214 print {$OUT} "Error: $@\n";
5218 # Good scalar. If it's a reference, find what it points to.
5220 print {$OUT} "Interpreted as: $1 $s\n";
5223 # Call self recursively to really do the command.
5225 } ## end if ($line =~ /^(\$.*)/s)
5227 # l name. Try to find a sub by that name.
5228 elsif ( ($subname) = $line =~ /\A([\':A-Za-z_][\':\w]*(?:\[.*\])?)/s ) {
5232 $subname =~ s/\'/::/;
5234 # Put it in this package unless it starts with ::.
5235 $subname = $package . "::" . $subname unless $subname =~ /::/;
5237 # Put it in CORE::GLOBAL if t doesn't start with :: and
5238 # it doesn't live in this package and it lives in CORE::GLOBAL.
5239 $subname = "CORE::GLOBAL::$s"
5240 if not defined &$subname
5242 and defined &{"CORE::GLOBAL::$s"};
5244 # Put leading '::' names into 'main::'.
5245 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
5247 # Get name:start-stop from find_sub, and break this up at
5249 my @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
5251 # Pull off start-stop.
5252 my $subrange = pop @pieces;
5254 # If the name contained colons, the split broke it up.
5255 # Put it back together.
5256 $file = join( ':', @pieces );
5258 # If we're not in that file, switch over to it.
5259 if ( $file ne $filename ) {
5260 print $OUT "Switching to file '$file'.\n"
5261 unless $slave_editor;
5263 # Switch debugger's magic structures.
5264 *dbline = $main::{ '_<' . $file };
5267 } ## end if ($file ne $filename)
5269 # Subrange is 'start-stop'. If this is less than a window full,
5270 # swap it to 'start+', which will list a window from the start point.
5272 if ( eval($subrange) < -$window ) {
5273 $subrange =~ s/-.*/+/;
5276 # Call self recursively to list the range.
5278 cmd_l( 'l', $subrange );
5279 } ## end if ($subrange)
5283 print $OUT "Subroutine $subname not found.\n";
5285 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s)
5288 elsif ( $line !~ /\S/ ) {
5290 # Compute new range to list.
5291 $incr = $window - 1;
5292 $line = $start . '-' . ( $start + $incr );
5295 cmd_l( 'l', $line );
5298 # l [start]+number_of_lines
5299 elsif ( my ($new_start, $new_incr) = $line =~ /\A(\d*)\+(\d*)\z/ ) {
5301 # Don't reset start for 'l +nnn'.
5302 $start = $new_start if $new_start;
5304 # Increment for list. Use window size if not specified.
5305 # (Allows 'l +' to work.)
5307 $incr = $window - 1 unless $incr;
5309 # Create a line range we'll understand, and recurse to do it.
5310 $line = $start . '-' . ( $start + $incr );
5311 cmd_l( 'l', $line );
5312 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/)
5314 # l start-stop or l start,stop
5315 elsif ( $line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/ ) {
5317 # Determine end point; use end of file if not specified.
5318 my $end = ( !defined $2 ) ? $max : ( $4 ? $4 : $2 );
5320 # Go on to the end, and then stop.
5321 $end = $max if $end > $max;
5323 # Determine start line.
5325 $i = $line if $i eq '.';
5329 # If we're running under a slave editor, force it to show the lines.
5330 if ($slave_editor) {
5331 print $OUT "\032\032$filename:$i:0\n";
5335 # We're doing it ourselves. We want to show the line and special
5337 # - the current line in execution
5338 # - whether a line is breakable or not
5339 # - whether a line has a break or not
5340 # - whether a line has an action or not
5342 for ( ; $i <= $end ; $i++ ) {
5344 # Check for breakpoints and actions.
5345 my ( $stop, $action );
5346 ( $stop, $action ) = split( /\0/, $dbline{$i} )
5349 # ==> if this is the current line in execution,
5350 # : if it's breakable.
5352 ( $i == $current_line and $filename eq $filename_ini )
5354 : ( $dbline[$i] + 0 ? ':' : ' ' );
5356 # Add break and action indicators.
5357 $arrow .= 'b' if $stop;
5358 $arrow .= 'a' if $action;
5361 print $OUT "$i$arrow\t", $dbline[$i];
5363 # Move on to the next line. Drop out on an interrupt.
5364 $i++, last if $signal;
5365 } ## end for (; $i <= $end ; $i++)
5367 # Line the prompt up; print a newline if the last line listed
5368 # didn't have a newline.
5369 print $OUT "\n" unless $dbline[ $i - 1 ] =~ /\n$/;
5370 } ## end else [ if ($slave_editor)
5372 # Save the point we last listed to in case another relative 'l'
5373 # command is desired. Don't let it run off the end.
5375 $start = $max if $start > $max;
5376 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/)
5379 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5381 To list breakpoints, the command has to look determine where all of them are
5382 first. It starts a C<%had_breakpoints>, which tells us what all files have
5383 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5384 magic source and breakpoint data structures) to the file, and then look
5385 through C<%dbline> for lines with breakpoints and/or actions, listing them
5386 out. We look through C<%postponed> not-yet-compiled subroutines that have
5387 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5388 that have breakpoints.
5390 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5397 # If no argument, list everything. Pre-5.8.0 version always lists
5399 my $arg = shift || 'abw';
5400 $arg = 'abw' unless $CommandSet eq '580'; # sigh...
5402 # See what is wanted.
5403 my $action_wanted = ( $arg =~ /a/ ) ? 1 : 0;
5404 my $break_wanted = ( $arg =~ /b/ ) ? 1 : 0;
5405 my $watch_wanted = ( $arg =~ /w/ ) ? 1 : 0;
5407 # Breaks and actions are found together, so we look in the same place
5409 if ( $break_wanted or $action_wanted ) {
5411 # Look in all the files with breakpoints...
5412 for my $file ( keys %had_breakpoints ) {
5414 # Temporary switch to this file.
5415 local *dbline = $main::{ '_<' . $file };
5417 # Set up to look through the whole file.
5419 my $was; # Flag: did we print something
5422 # For each line in the file ...
5423 for my $i (1 .. $max) {
5425 # We've got something on this line.
5426 if ( defined $dbline{$i} ) {
5428 # Print the header if we haven't.
5429 print $OUT "$file:\n" unless $was++;
5432 print $OUT " $i:\t", $dbline[$i];
5434 # Pull out the condition and the action.
5435 my ( $stop, $action ) = split( /\0/, $dbline{$i} );
5437 # Print the break if there is one and it's wanted.
5438 print $OUT " break if (", $stop, ")\n"
5442 # Print the action if there is one and it's wanted.
5443 print $OUT " action: ", $action, "\n"
5447 # Quit if the user hit interrupt.
5449 } ## end if (defined $dbline{$i...
5450 } ## end for my $i (1 .. $max)
5451 } ## end for my $file (keys %had_breakpoints)
5452 } ## end if ($break_wanted or $action_wanted)
5454 # Look for breaks in not-yet-compiled subs:
5455 if ( %postponed and $break_wanted ) {
5456 print $OUT "Postponed breakpoints in subroutines:\n";
5458 for $subname ( keys %postponed ) {
5459 print $OUT " $subname\t$postponed{$subname}\n";
5462 } ## end if (%postponed and $break_wanted)
5464 # Find files that have not-yet-loaded breaks:
5465 my @have = map { # Combined keys
5466 keys %{ $postponed_file{$_} }
5467 } keys %postponed_file;
5469 # If there are any, list them.
5470 if ( @have and ( $break_wanted or $action_wanted ) ) {
5471 print $OUT "Postponed breakpoints in files:\n";
5472 for my $file ( keys %postponed_file ) {
5473 my $db = $postponed_file{$file};
5474 print $OUT " $file:\n";
5475 for my $line ( sort { $a <=> $b } keys %$db ) {
5476 print $OUT " $line:\n";
5477 my ( $stop, $action ) = split( /\0/, $$db{$line} );
5478 print $OUT " break if (", $stop, ")\n"
5481 print $OUT " action: ", $action, "\n"
5485 } ## end for $line (sort { $a <=>...
5487 } ## end for $file (keys %postponed_file)
5488 } ## end if (@have and ($break_wanted...
5489 if ( %break_on_load and $break_wanted ) {
5490 print {$OUT} "Breakpoints on load:\n";
5491 BREAK_ON_LOAD: for my $filename ( keys %break_on_load ) {
5492 print {$OUT} " $filename\n";
5493 last BREAK_ON_LOAD if $signal;
5495 } ## end if (%break_on_load and...
5496 if ($watch_wanted and ( $trace & 2 )) {
5497 print {$OUT} "Watch-expressions:\n" if @to_watch;
5498 TO_WATCH: for my $expr (@to_watch) {
5499 print {$OUT} " $expr\n";
5500 last TO_WATCH if $signal;
5505 =head3 C<cmd_M> - list modules (command)
5507 Just call C<list_modules>.
5517 =head3 C<cmd_o> - options (command)
5519 If this is just C<o> by itself, we list the current settings via
5520 C<dump_option>. If there's a nonblank value following it, we pass that on to
5521 C<parse_options> for processing.
5527 my $opt = shift || ''; # opt[=val]
5529 # Nonblank. Try to parse and process.
5530 if ( $opt =~ /^(\S.*)/ ) {
5534 # Blank. List the current option settings.
5542 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5544 Advises the user that the O command has been renamed.
5549 print $OUT "The old O command is now the o command.\n"; # hint
5550 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5551 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5554 =head3 C<cmd_v> - view window (command)
5556 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5557 move back a few lines to list the selected line in context. Uses C<cmd_l>
5558 to do the actual listing after figuring out the range of line to request.
5562 use vars qw($preview);
5568 # Extract the line to list around. (Astute readers will have noted that
5569 # this pattern will match whether or not a numeric line is specified,
5570 # which means that we'll always enter this loop (though a non-numeric
5571 # argument results in no action at all)).
5572 if ( $line =~ /^(\d*)$/ ) {
5574 # Total number of lines to list (a windowful).
5575 $incr = $window - 1;
5577 # Set the start to the argument given (if there was one).
5580 # Back up by the context amount.
5583 # Put together a linespec that cmd_l will like.
5584 $line = $start . '-' . ( $start + $incr );
5587 cmd_l( 'l', $line );
5588 } ## end if ($line =~ /^(\d*)$/)
5591 =head3 C<cmd_w> - add a watch expression (command)
5593 The 5.8 version of this command adds a watch expression if one is specified;
5594 it does nothing if entered with no operands.
5596 We extract the expression, save it, evaluate it in the user's context, and
5597 save the value. We'll re-evaluate it each time the debugger passes a line,
5598 and will stop (see the code at the top of the command loop) if the value
5599 of any of the expressions changes.
5603 sub _add_watch_expr {
5607 push @to_watch, $expr;
5609 # Parameterize DB::eval and call it to get the expression's value
5610 # in the user's context. This version can handle expressions which
5611 # return a list value.
5613 my ($val) = join( ' ', DB::eval() );
5614 $val = ( defined $val ) ? "'$val'" : 'undef';
5616 # Save the current value of the expression.
5617 push @old_watch, $val;
5619 # We are now watching expressions.
5628 # Null expression if no arguments.
5629 my $expr = shift || '';
5631 # If expression is not null ...
5632 if ( $expr =~ /\A\S/ ) {
5633 _add_watch_expr($expr);
5634 } ## end if ($expr =~ /^(\S.*)/)
5636 # You have to give one to get one.
5638 print $OUT "Adding a watch-expression requires an expression\n"; # hint
5644 =head3 C<cmd_W> - delete watch expressions (command)
5646 This command accepts either a watch expression to be removed from the list
5647 of watch expressions, or C<*> to delete them all.
5649 If C<*> is specified, we simply empty the watch expression list and the
5650 watch expression value list. We also turn off the bit that says we've got
5653 If an expression (or partial expression) is specified, we pattern-match
5654 through the expressions and remove the ones that match. We also discard
5655 the corresponding values. If no watch expressions are left, we turn off
5656 the I<watching expressions> bit.
5662 my $expr = shift || '';
5665 if ( $expr eq '*' ) {
5670 print $OUT "Deleting all watch expressions ...\n";
5673 @to_watch = @old_watch = ();
5676 # Delete one of them.
5677 elsif ( $expr =~ /^(\S.*)/ ) {
5679 # Where we are in the list.
5682 # For each expression ...
5683 foreach (@to_watch) {
5684 my $val = $to_watch[$i_cnt];
5686 # Does this one match the command argument?
5687 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
5688 # Yes. Turn it off, and its value too.
5689 splice( @to_watch, $i_cnt, 1 );
5690 splice( @old_watch, $i_cnt, 1 );
5693 } ## end foreach (@to_watch)
5695 # We don't bother to turn watching off because
5696 # a) we don't want to stop calling watchfunction() it it exists
5697 # b) foreach over a null list doesn't do anything anyway
5699 } ## end elsif ($expr =~ /^(\S.*)/)
5701 # No command arguments entered.
5704 "Deleting a watch-expression requires an expression, or '*' for all\n"
5709 ### END of the API section
5711 =head1 SUPPORT ROUTINES
5713 These are general support routines that are used in a number of places
5714 throughout the debugger.
5718 save() saves the user's versions of globals that would mess us up in C<@saved>,
5719 and installs the versions we like better.
5725 # Save eval failure, command failure, extended OS error, output field
5726 # separator, input record separator, output record separator and
5727 # the warning setting.
5728 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
5730 $, = ""; # output field separator is null string
5731 $/ = "\n"; # input record separator is newline
5732 $\ = ""; # output record separator is null string
5733 $^W = 0; # warnings are off
5736 =head2 C<print_lineinfo> - show where we are now
5738 print_lineinfo prints whatever it is that it is handed; it prints it to the
5739 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
5740 us to feed line information to a slave editor without messing up the
5745 sub print_lineinfo {
5747 # Make the terminal sensible if we're not the primary debugger.
5748 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
5752 } ## end sub print_lineinfo
5754 =head2 C<postponed_sub>
5756 Handles setting postponed breakpoints in subroutines once they're compiled.
5757 For breakpoints, we use C<DB::find_sub> to locate the source file and line
5758 range for the subroutine, then mark the file as having a breakpoint,
5759 temporarily switch the C<*dbline> glob over to the source file, and then
5760 search the given range of lines to find a breakable line. If we find one,
5761 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
5765 # The following takes its argument via $evalarg to preserve current @_
5769 # Get the subroutine name.
5770 my $subname = shift;
5772 # If this is a 'break +<n> if <condition>' ...
5773 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
5775 # If there's no offset, use '+0'.
5776 my $offset = $1 || 0;
5778 # find_sub's value is 'fullpath-filename:start-stop'. It's
5779 # possible that the filename might have colons in it too.
5780 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
5783 # We got the start line. Add the offset '+<n>' from
5784 # $postponed{subname}.
5787 # Switch to the file this sub is in, temporarily.
5788 local *dbline = $main::{ '_<' . $file };
5790 # No warnings, please.
5791 local $^W = 0; # != 0 is magical below
5793 # This file's got a breakpoint in it.
5794 $had_breakpoints{$file} |= 1;
5796 # Last line in file.
5799 # Search forward until we hit a breakable line or get to
5800 # the end of the file.
5801 ++$i until $dbline[$i] != 0 or $i >= $max;
5803 # Copy the breakpoint in and delete it from %postponed.
5804 $dbline{$i} = delete $postponed{$subname};
5807 # find_sub didn't find the sub.
5810 print $OUT "Subroutine $subname not found.\n";
5813 } ## end if ($postponed{$subname...
5814 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
5816 #print $OUT "In postponed_sub for '$subname'.\n";
5817 } ## end sub postponed_sub
5821 Called after each required file is compiled, but before it is executed;
5822 also called if the name of a just-compiled subroutine is a key of
5823 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
5824 etc.) into the just-compiled code.
5826 If this is a C<require>'d file, the incoming parameter is the glob
5827 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
5829 If it's a subroutine, the incoming parameter is the subroutine name.
5835 # If there's a break, process it.
5836 if ($ImmediateStop) {
5838 # Right, we've stopped. Turn it off.
5841 # Enter the command loop when DB::DB gets called.
5845 # If this is a subroutine, let postponed_sub() deal with it.
5846 return &postponed_sub unless ref \$_[0] eq 'GLOB';
5848 # Not a subroutine. Deal with the file.
5849 local *dbline = shift;
5850 my $filename = $dbline;
5851 $filename =~ s/^_<//;
5853 $signal = 1, print $OUT "'$filename' loaded...\n"
5854 if $break_on_load{$filename};
5855 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
5857 # Do we have any breakpoints to put in this file?
5858 return unless $postponed_file{$filename};
5860 # Yes. Mark this file as having breakpoints.
5861 $had_breakpoints{$filename} |= 1;
5863 # "Cannot be done: insufficient magic" - we can't just put the
5864 # breakpoints saved in %postponed_file into %dbline by assigning
5865 # the whole hash; we have to do it one item at a time for the
5866 # breakpoints to be set properly.
5867 #%dbline = %{$postponed_file{$filename}};
5869 # Set the breakpoints, one at a time.
5872 for $key ( keys %{ $postponed_file{$filename} } ) {
5874 # Stash the saved breakpoint into the current file's magic line array.
5875 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
5878 # This file's been compiled; discard the stored breakpoints.
5879 delete $postponed_file{$filename};
5881 } ## end sub postponed
5885 C<dumpit> is the debugger's wrapper around dumpvar.pl.
5887 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
5888 a reference to a variable (the thing to be dumped) as its input.
5890 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
5891 the currently-selected filehandle, thank you very much). The current
5892 values of the package globals C<$single> and C<$trace> are backed up in
5893 lexicals, and they are turned off (this keeps the debugger from trying
5894 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
5895 preserve its current value and it is set to zero to prevent entry/exit
5896 messages from printing, and C<$doret> is localized as well and set to -2 to
5897 prevent return values from being shown.
5899 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
5900 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
5901 installed version in C<@INC>, yours will be used instead. Possible security
5904 It then checks to see if the subroutine C<main::dumpValue> is now defined
5905 it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
5906 localizes the globals necessary for things to be sane when C<main::dumpValue()>
5907 is called, and picks up the variable to be dumped from the parameter list.
5909 It checks the package global C<%options> to see if there's a C<dumpDepth>
5910 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
5911 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
5912 structure: -1 means dump everything.
5914 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
5917 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
5918 and we then return to the caller.
5924 # Save the current output filehandle and switch to the one
5925 # passed in as the first parameter.
5926 my $savout = select(shift);
5928 # Save current settings of $single and $trace, and then turn them off.
5929 my $osingle = $single;
5930 my $otrace = $trace;
5931 $single = $trace = 0;
5933 # XXX Okay, what do $frame and $doret do, again?
5937 # Load dumpvar.pl unless we've already got the sub we need from it.
5938 unless ( defined &main::dumpValue ) {
5939 do 'dumpvar.pl' or die $@;
5942 # If the load succeeded (or we already had dumpvalue()), go ahead
5944 if ( defined &main::dumpValue ) {
5949 my $maxdepth = shift || $option{dumpDepth};
5950 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
5951 &main::dumpValue( $v, $maxdepth );
5952 } ## end if (defined &main::dumpValue)
5954 # Oops, couldn't load dumpvar.pl.
5957 print $OUT "dumpvar.pl not available.\n";
5960 # Reset $single and $trace to their old values.
5964 # Restore the old filehandle.
5968 =head2 C<print_trace>
5970 C<print_trace>'s job is to print a stack trace. It does this via the
5971 C<dump_trace> routine, which actually does all the ferreting-out of the
5972 stack trace data. C<print_trace> takes care of formatting it nicely and
5973 printing it to the proper filehandle.
5981 The filehandle to print to.
5985 How many frames to skip before starting trace.
5989 How many frames to print.
5993 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
5997 The original comment below seems to be noting that the traceback may not be
5998 correct if this routine is called in a tied method.
6002 # Tied method do not create a context, so may get wrong message:
6008 # If this is going to a slave editor, but we're not the primary
6009 # debugger, reset it first.
6011 if $fh eq $LINEINFO # slave editor
6012 and $LINEINFO eq $OUT # normal output
6013 and $term_pid != $$; # not the primary
6015 # Collect the actual trace information to be formatted.
6016 # This is an array of hashes of subroutine call info.
6017 my @sub = dump_trace( $_[0] + 1, $_[1] );
6019 # Grab the "short report" flag from @_.
6020 my $short = $_[2]; # Print short report, next one for sub name
6022 # Run through the traceback info, format it, and print it.
6024 for my $i (0 .. $#sub) {
6026 # Drop out if the user has lost interest and hit control-C.
6029 # Set the separator so arrys print nice.
6032 # Grab and stringify the arguments if they are there.
6034 defined $sub[$i]{args}
6035 ? "(@{ $sub[$i]{args} })"
6038 # Shorten them up if $maxtrace says they're too long.
6039 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
6040 if length $args > $maxtrace;
6042 # Get the file name.
6043 my $file = $sub[$i]{file};
6045 # Put in a filename header if short is off.
6046 $file = $file eq '-e' ? $file : "file '$file'" unless $short;
6048 # Get the actual sub's name, and shorten to $maxtrace's requirement.
6050 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
6052 # Short report uses trimmed file and sub names.
6054 my $sub = @_ >= 4 ? $_[3] : $s;
6055 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
6056 } ## end if ($short)
6058 # Non-short report includes full names.
6060 print $fh "$sub[$i]{context} = $s$args"
6061 . " called from $file"
6062 . " line $sub[$i]{line}\n";
6064 } ## end for my $i (0 .. $#sub)
6065 } ## end sub print_trace
6067 =head2 dump_trace(skip[,count])
6069 Actually collect the traceback information available via C<caller()>. It does
6070 some filtering and cleanup of the data, but mostly it just collects it to
6071 make C<print_trace()>'s job easier.
6073 C<skip> defines the number of stack frames to be skipped, working backwards
6074 from the most current. C<count> determines the total number of frames to
6075 be returned; all of them (well, the first 10^9) are returned if C<count>
6078 This routine returns a list of hashes, from most-recent to least-recent
6079 stack frame. Each has the following keys and values:
6083 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
6085 =item * C<sub> - subroutine name, or C<eval> information
6087 =item * C<args> - undef, or a reference to an array of arguments
6089 =item * C<file> - the file in which this item was defined (if any)
6091 =item * C<line> - the line on which it was defined
6099 # How many levels to skip.
6102 # How many levels to show. (1e9 is a cheap way of saying "all of them";
6103 # it's unlikely that we'll have more than a billion stack frames. If you
6104 # do, you've got an awfully big machine...)
6105 my $count = shift || 1e9;
6107 # We increment skip because caller(1) is the first level *back* from
6108 # the current one. Add $skip to the count of frames so we have a
6109 # simple stop criterion, counting from $skip to $count+$skip.
6113 # These variables are used to capture output from caller();
6114 my ( $p, $file, $line, $sub, $h, $context );
6116 my ( $e, $r, @a, @sub, $args );
6118 # XXX Okay... why'd we do that?
6119 my $nothard = not $frame & 8;
6122 # Do not want to trace this.
6123 my $otrace = $trace;
6126 # Start out at the skip count.
6127 # If we haven't reached the number of frames requested, and caller() is
6128 # still returning something, stay in the loop. (If we pass the requested
6129 # number of stack frames, or we run out - caller() returns nothing - we
6131 # Up the stack frame index to go back one more level each time.
6135 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
6140 # Go through the arguments and save them for later.
6142 for my $arg (@args) {
6144 if ( not defined $arg ) { # undefined parameter
6148 elsif ( $nothard and tied $arg ) { # tied parameter
6151 elsif ( $nothard and $type = ref $arg ) { # reference
6152 push @a, "ref($type)";
6154 else { # can be stringified
6156 "$arg"; # Safe to stringify now - should not call f().
6158 # Backslash any single-quotes or backslashes.
6161 # Single-quote it unless it's a number or a colon-separated
6164 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
6166 # Turn high-bit characters into meta-whatever.
6167 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
6169 # Turn control characters into ^-whatever.
6170 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
6173 } ## end else [ if (not defined $arg)
6174 } ## end for $arg (@args)
6176 # If context is true, this is array (@)context.
6177 # If context is false, this is scalar ($) context.
6178 # If neither, context isn't defined. (This is apparently a 'can't
6180 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
6182 # if the sub has args ($h true), make an anonymous array of the
6184 $args = $h ? [@a] : undef;
6186 # remove trailing newline-whitespace-semicolon-end of line sequence
6187 # from the eval text, if any.
6188 $e =~ s/\n\s*\;\s*\Z// if $e;
6190 # Escape backslashed single-quotes again if necessary.
6191 $e =~ s/([\\\'])/\\$1/g if $e;
6193 # if the require flag is true, the eval text is from a require.
6195 $sub = "require '$e'";
6198 # if it's false, the eval text is really from an eval.
6199 elsif ( defined $r ) {
6203 # If the sub is '(eval)', this is a block eval, meaning we don't
6204 # know what the eval'ed text actually was.
6205 elsif ( $sub eq '(eval)' ) {
6206 $sub = "eval {...}";
6209 # Stick the collected information into @sub as an anonymous hash.
6213 context => $context,
6221 # Stop processing frames if the user hit control-C.
6223 } ## end for ($i = $skip ; $i < ...
6225 # Restore the trace value again.
6228 } ## end sub dump_trace
6232 C<action()> takes input provided as the argument to an add-action command,
6233 either pre- or post-, and makes sure it's a complete command. It doesn't do
6234 any fancy parsing; it just keeps reading input until it gets a string
6235 without a trailing backslash.
6242 while ( $action =~ s/\\$// ) {
6244 # We have a backslash on the end. Read more.
6246 } ## end while ($action =~ s/\\$//)
6248 # Return the assembled action.
6254 This routine mostly just packages up a regular expression to be used
6255 to check that the thing it's being matched against has properly-matched
6258 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
6259 speeds things up by only creating the qr//'ed expression once; if it's
6260 already defined, we don't try to define it again. A speed hack.
6264 use vars qw($balanced_brace_re);
6268 # I hate using globals!
6269 $balanced_brace_re ||= qr{
6272 (?> [^{}] + ) # Non-parens without backtracking
6274 (??{ $balanced_brace_re }) # Group with matching parens
6278 return $_[0] !~ m/$balanced_brace_re/;
6279 } ## end sub unbalanced
6283 C<gets()> is a primitive (very primitive) routine to read continuations.
6284 It was devised for reading continuations for actions.
6285 it just reads more input with C<readline()> and returns it.
6290 &readline("cont: ");
6293 =head2 C<DB::system()> - handle calls to<system()> without messing up the debugger
6295 The C<system()> function assumes that it can just go ahead and use STDIN and
6296 STDOUT, but under the debugger, we want it to use the debugger's input and
6299 C<DB::system()> socks away the program's STDIN and STDOUT, and then substitutes
6300 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
6301 and then puts everything back again.
6307 # We save, change, then restore STDIN and STDOUT to avoid fork() since
6308 # some non-Unix systems can do system() but have problems with fork().
6309 open( SAVEIN, "<&STDIN" ) || &warn("Can't save STDIN");
6310 open( SAVEOUT, ">&STDOUT" ) || &warn("Can't save STDOUT");
6311 open( STDIN, "<&IN" ) || &warn("Can't redirect STDIN");
6312 open( STDOUT, ">&OUT" ) || &warn("Can't redirect STDOUT");
6314 # XXX: using csh or tcsh destroys sigint retvals!
6316 open( STDIN, "<&SAVEIN" ) || &warn("Can't restore STDIN");
6317 open( STDOUT, ">&SAVEOUT" ) || &warn("Can't restore STDOUT");
6321 # most of the $? crud was coping with broken cshisms
6323 &warn( "(Command exited ", ( $? >> 8 ), ")\n" );
6327 "(Command died of SIG#",
6329 ( ( $? & 128 ) ? " -- core dumped" : "" ),
6338 =head1 TTY MANAGEMENT
6340 The subs here do some of the terminal management for multiple debuggers.
6344 Top-level function called when we want to set up a new terminal for use
6347 If the C<noTTY> debugger option was set, we'll either use the terminal
6348 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
6349 to find one. If we're a forked debugger, we call C<resetterm> to try to
6350 get a whole new terminal if we can.
6352 In either case, we set up the terminal next. If the C<ReadLine> option was
6353 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6354 the appropriate attributes. We then
6358 use vars qw($ornaments);
6359 use vars qw($rl_attribs);
6363 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6366 require Term::ReadLine;
6368 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6371 my ( $i, $o ) = split $tty, /,/;
6372 $o = $i unless defined $o;
6373 open( IN, "<$i" ) or die "Cannot open TTY '$i' for read: $!";
6374 open( OUT, ">$o" ) or die "Cannot open TTY '$o' for write: $!";
6380 # We don't have a TTY - try to find one via Term::Rendezvous.
6382 require Term::Rendezvous;
6384 # See if we have anything to pass to Term::Rendezvous.
6385 # Use $HOME/.perldbtty$$ if not.
6386 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6388 # Rendezvous and get the filehandles.
6389 my $term_rv = Term::Rendezvous->new( $rv );
6391 $OUT = $term_rv->OUT;
6392 } ## end else [ if ($tty)
6393 } ## end if ($notty)
6395 # We're a daughter debugger. Try to fork off another TTY.
6396 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6400 # If we shouldn't use Term::ReadLine, don't.
6402 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6405 # We're using Term::ReadLine. Get all the attributes for this terminal.
6407 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6409 $rl_attribs = $term->Attribs;
6410 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6411 if defined $rl_attribs->{basic_word_break_characters}
6412 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6413 $rl_attribs->{special_prefixes} = '$@&%';
6414 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6415 $rl_attribs->{completion_function} = \&db_complete;
6416 } ## end else [ if (!$rl)
6418 # Set up the LINEINFO filehandle.
6419 $LINEINFO = $OUT unless defined $LINEINFO;
6420 $lineinfo = $console unless defined $lineinfo;
6426 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6427 $term->SetHistory(@hist);
6430 # XXX Ornaments are turned on unconditionally, which is not
6431 # always a good thing.
6432 ornaments($ornaments) if defined $ornaments;
6434 } ## end sub setterm
6437 $histfile //= option_val("HistFile", undef);
6438 return unless defined $histfile;
6439 open my $fh, "<", $histfile or return;
6450 return unless defined $histfile;
6451 eval { require File::Path } or return;
6452 eval { require File::Basename } or return;
6453 File::Path::mkpath(File::Basename::dirname($histfile));
6454 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6455 $histsize //= option_val("HistSize",100);
6456 my @copy = grep { $_ ne '?' } @hist;
6457 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6458 for ($start .. $#copy) {
6459 print $fh "$copy[$_]\n";
6461 close $fh or die "Could not write '$histfile': $!";
6464 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6466 When the process being debugged forks, or the process invokes a command
6467 via C<system()> which starts a new debugger, we need to be able to get a new
6468 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6469 fight over the terminal, and you can never quite be sure who's going to get the
6470 input you're typing.
6472 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6473 is tasked with doing all the necessary operating system mojo to get a new
6474 TTY (and probably another window) and to direct the new debugger to read and
6477 The debugger provides C<get_fork_TTY> functions which work for TCP
6478 socket servers, X11, OS/2, and Mac OS X. Other systems are not
6479 supported. You are encouraged to write C<get_fork_TTY> functions which
6480 work for I<your> platform and contribute them.
6482 =head3 C<socket_get_fork_TTY>
6486 sub connect_remoteport {
6489 my $socket = IO::Socket::INET->new(
6491 PeerAddr => $remoteport,
6495 die "Unable to connect to remote host: $remoteport\n";
6500 sub socket_get_fork_TTY {
6501 $tty = $LINEINFO = $IN = $OUT = connect_remoteport();
6503 # Do I need to worry about setting $term?
6505 reset_IN_OUT( $IN, $OUT );
6509 =head3 C<xterm_get_fork_TTY>
6511 This function provides the C<get_fork_TTY> function for X11. If a
6512 program running under the debugger forks, a new <xterm> window is opened and
6513 the subsidiary debugger is directed there.
6515 The C<open()> call is of particular note here. We have the new C<xterm>
6516 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6517 command (which prints the device name of the TTY we'll want to use for input
6518 and output to STDOUT, then C<sleep> for a very long time, routing this output
6519 to file number 3. This way we can simply read from the <XT> filehandle (which
6520 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6522 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6527 sub xterm_get_fork_TTY {
6528 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6530 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6533 # Get the output from 'tty' and clean it up a little.
6537 $pidprompt = ''; # Shown anyway in titlebar
6539 # We need $term defined or we can not switch to the newly created xterm
6540 if ($tty ne '' && !defined $term) {
6541 require Term::ReadLine;
6543 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6546 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6549 # There's our new TTY.
6551 } ## end sub xterm_get_fork_TTY
6553 =head3 C<os2_get_fork_TTY>
6555 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6559 # This example function resets $IN, $OUT itself
6561 sub os2_get_fork_TTY { # A simplification of the following (and works without):
6563 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6564 my %opt = ( title => "Daughter Perl debugger $pids $name",
6565 ($rl ? (read_by_key => 1) : ()) );
6566 require OS2::Process;
6567 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
6569 $pidprompt = ''; # Shown anyway in titlebar
6570 reset_IN_OUT($in, $out);
6572 return ''; # Indicate that reset_IN_OUT is called
6573 } ## end sub os2_get_fork_TTY
6575 =head3 C<macosx_get_fork_TTY>
6577 The Mac OS X version uses AppleScript to tell Terminal.app to create
6582 # Notes about Terminal.app's AppleScript support,
6583 # (aka things that might break in future OS versions).
6585 # The "do script" command doesn't return a reference to the new window
6586 # it creates, but since it appears frontmost and windows are enumerated
6587 # front to back, we can use "first window" === "window 1".
6589 # Since "do script" is implemented by supplying the argument (plus a
6590 # return character) as terminal input, there's a potential race condition
6591 # where the debugger could beat the shell to reading the command.
6592 # To prevent this, we wait for the screen to clear before proceeding.
6595 # There's no direct accessor for the tty device name, so we fiddle
6596 # with the window title options until it says what we want.
6599 # There _is_ a direct accessor for the tty device name, _and_ there's
6600 # a new possible component of the window title (the name of the settings
6601 # set). A separate version is needed.
6603 my @script_versions=
6605 ([237, <<'__LEOPARD__'],
6606 tell application "Terminal"
6607 do script "clear;exec sleep 100000"
6608 tell first tab of first window
6610 set custom title to "forked perl debugger"
6611 set title displays custom title to true
6612 repeat while (length of first paragraph of (get contents)) > 0
6620 [100, <<'__JAGUAR_TIGER__'],
6621 tell application "Terminal"
6622 do script "clear;exec sleep 100000"
6624 set title displays shell path to false
6625 set title displays window size to false
6626 set title displays file name to false
6627 set title displays device name to true
6628 set title displays custom title to true
6629 set custom title to ""
6630 copy "/dev/" & name to thetty
6631 set custom title to "forked perl debugger"
6632 repeat while (length of first paragraph of (get contents)) > 0
6642 sub macosx_get_fork_TTY
6644 my($version,$script,$pipe,$tty);
6646 return unless $version=$ENV{TERM_PROGRAM_VERSION};
6647 foreach my $entry (@script_versions) {
6648 if ($version>=$entry->[0]) {
6649 $script=$entry->[1];
6653 return unless defined($script);
6654 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script);
6655 $tty=readline($pipe);
6657 return unless defined($tty) && $tty =~ m(^/dev/);
6662 =head2 C<create_IN_OUT($flags)>
6664 Create a new pair of filehandles, pointing to a new TTY. If impossible,
6665 try to diagnose why.
6671 =item * 1 - Don't know how to create a new TTY.
6673 =item * 2 - Debugger has forked, but we can't get a new TTY.
6675 =item * 4 - standard debugger startup is happening.
6681 use vars qw($fork_TTY);
6683 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
6685 # If we know how to get a new TTY, do it! $in will have
6686 # the TTY name if get_fork_TTY works.
6687 my $in = &get_fork_TTY if defined &get_fork_TTY;
6689 # It used to be that
6690 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
6692 if ( not defined $in ) {
6695 # We don't know how.
6696 print_help(<<EOP) if $why == 1;
6697 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
6701 print_help(<<EOP) if $why == 2;
6702 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
6703 This may be an asynchronous session, so the parent debugger may be active.
6706 # Note that both debuggers are fighting over the same input.
6707 print_help(<<EOP) if $why != 4;
6708 Since two debuggers fight for the same TTY, input is severely entangled.
6712 I know how to switch the output to a different window in xterms, OS/2
6713 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
6714 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
6715 B<DB::get_fork_TTY()> returning this.
6717 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
6718 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
6721 } ## end if (not defined $in)
6722 elsif ( $in ne '' ) {
6726 $console = ''; # Indicate no need to open-from-the-console
6729 } ## end sub create_IN_OUT
6733 Handles rejiggering the prompt when we've forked off a new debugger.
6735 If the new debugger happened because of a C<system()> that invoked a
6736 program under the debugger, the arrow between the old pid and the new
6737 in the prompt has I<two> dashes instead of one.
6739 We take the current list of pids and add this one to the end. If there
6740 isn't any list yet, we make one up out of the initial pid associated with
6741 the terminal and our new pid, sticking an arrow (either one-dashed or
6742 two dashed) in between them.
6744 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
6745 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
6750 sub resetterm { # We forked, so we need a different TTY
6752 # Needs to be passed to create_IN_OUT() as well.
6755 # resetterm(2): got in here because of a system() starting a debugger.
6756 # resetterm(1): just forked.
6757 my $systemed = $in > 1 ? '-' : '';
6759 # If there's already a list of pids, add this to the end.
6761 $pids =~ s/\]/$systemed->$$]/;
6764 # No pid list. Time to make one.
6766 $pids = "[$term_pid->$$]";
6769 # The prompt we're going to be using for this debugger.
6772 # We now 0wnz this terminal.
6775 # Just return if we're not supposed to try to create a new TTY.
6776 return unless $CreateTTY & $in;
6778 # Try to create a new IN/OUT pair.
6780 } ## end sub resetterm
6784 First, we handle stuff in the typeahead buffer. If there is any, we shift off
6785 the next line, print a message saying we got it, add it to the terminal
6786 history (if possible), and return it.
6788 If there's nothing in the typeahead buffer, check the command filehandle stack.
6789 If there are any filehandles there, read from the last one, and return the line
6790 if we got one. If not, we pop the filehandle off and close it, and try the
6791 next one up the stack.
6793 If we've emptied the filehandle stack, we check to see if we've got a socket
6794 open, and we read that and return it if we do. If we don't, we just call the
6795 core C<readline()> and return its value.
6801 # Localize to prevent it from being smashed in the program being debugged.
6804 # If there are stacked filehandles to read from ...
6805 # (Handle it before the typeahead, because we may call source/etc. from
6809 # Read from the last one in the stack.
6810 my $line = CORE::readline( $cmdfhs[-1] );
6812 # If we got a line ...
6814 ? ( print $OUT ">> $line" and return $line ) # Echo and return
6815 : close pop @cmdfhs; # Pop and close
6816 } ## end while (@cmdfhs)
6818 # Pull a line out of the typeahead if there's stuff there.
6821 # How many lines left.
6822 my $left = @typeahead;
6824 # Get the next line.
6825 my $got = shift @typeahead;
6827 # Print a message saying we got input from the typeahead.
6829 print $OUT "auto(-$left)", shift, $got, "\n";
6831 # Add it to the terminal history (if possible).
6832 $term->AddHistory($got)
6834 and defined $term->Features->{addHistory};
6836 } ## end if (@typeahead)
6838 # We really need to read some input. Turn off entry/exit trace and
6839 # return value printing.
6843 # Nothing on the filehandle stack. Socket?
6844 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
6846 # Send anything we have to send.
6847 $OUT->write( join( '', @_ ) );
6849 # Receive anything there is to receive.
6854 while ($first_time or (length($buf) && ($stuff .= $buf) !~ /\n/))
6857 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
6858 # XXX Don't know. You tell me.
6863 } ## end if (ref $OUT and UNIVERSAL::isa...
6865 # No socket. Just read from the terminal.
6867 return $term->readline(@_);
6869 } ## end sub readline
6871 =head1 OPTIONS SUPPORT ROUTINES
6873 These routines handle listing and setting option values.
6875 =head2 C<dump_option> - list the current value of an option setting
6877 This routine uses C<option_val> to look up the value for an option.
6878 It cleans up escaped single-quotes and then displays the option and
6884 my ( $opt, $val ) = @_;
6885 $val = option_val( $opt, 'N/A' );
6886 $val =~ s/([\\\'])/\\$1/g;
6887 printf $OUT "%20s = '%s'\n", $opt, $val;
6888 } ## end sub dump_option
6890 sub options2remember {
6891 foreach my $k (@RememberOnROptions) {
6892 $option{$k} = option_val( $k, 'N/A' );
6897 =head2 C<option_val> - find the current value of an option
6899 This can't just be a simple hash lookup because of the indirect way that
6900 the option values are stored. Some are retrieved by calling a subroutine,
6901 some are just variables.
6903 You must supply a default value to be used in case the option isn't set.
6908 my ( $opt, $default ) = @_;
6911 # Does this option exist, and is it a variable?
6912 # If so, retrieve the value via the value in %optionVars.
6913 if ( defined $optionVars{$opt}
6914 and defined ${ $optionVars{$opt} } )
6916 $val = ${ $optionVars{$opt} };
6919 # Does this option exist, and it's a subroutine?
6920 # If so, call the subroutine via the ref in %optionAction
6921 # and capture the value.
6922 elsif ( defined $optionAction{$opt}
6923 and defined &{ $optionAction{$opt} } )
6925 $val = &{ $optionAction{$opt} }();
6928 # If there's an action or variable for the supplied option,
6929 # but no value was set, use the default.
6930 elsif (defined $optionAction{$opt} and not defined $option{$opt}
6931 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
6936 # Otherwise, do the simple hash lookup.
6938 $val = $option{$opt};
6941 # If the value isn't defined, use the default.
6942 # Then return whatever the value is.
6943 $val = $default unless defined $val;
6945 } ## end sub option_val
6947 =head2 C<parse_options>
6949 Handles the parsing and execution of option setting/displaying commands.
6951 An option entered by itself is assumed to be I<set me to 1> (the default value)
6952 if the option is a boolean one. If not, the user is prompted to enter a valid
6953 value or to query the current value (via C<option? >).
6955 If C<option=value> is entered, we try to extract a quoted string from the
6956 value (if it is quoted). If it's not, we just use the whole value as-is.
6958 We load any modules required to service this option, and then we set it: if
6959 it just gets stuck in a variable, we do that; if there's a subroutine to
6960 handle setting the option, we call that.
6962 Finally, if we're running in interactive mode, we display the effect of the
6963 user's command back to the terminal, skipping this if we're setting things
6964 during initialization.
6974 # These options need a value. Don't allow them to be clobbered by accident.
6975 my %opt_needs_val = map { ( $_ => 1 ) } qw{
6976 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
6977 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
6980 while (length($s)) {
6983 # Clean off excess leading whitespace.
6984 $s =~ s/^\s+// && next;
6986 # Options are always all word characters, followed by a non-word
6988 if ($s !~ s/^(\w+)(\W?)//) {
6989 print {$OUT} "Invalid option '$s'\n";
6992 my ( $opt, $sep ) = ( $1, $2 );
6994 # Make sure that such an option exists.
6995 my $matches = ( grep { /^\Q$opt/ && ( $option = $_ ) } @options )
6996 || ( grep { /^\Q$opt/i && ( $option = $_ ) } @options );
6999 print {$OUT} "Unknown option '$opt'\n";
7003 print {$OUT} "Ambiguous option '$opt'\n";
7008 # '?' as separator means query, but must have whitespace after it.
7009 if ( "?" eq $sep ) {
7011 print {$OUT} "Option query '$opt?' followed by non-space '$s'\n" ;
7016 #&dump_option($opt);
7017 } ## end if ("?" eq $sep)
7019 # Separator is whitespace (or just a carriage return).
7020 # They're going for a default, which we assume is 1.
7021 elsif ( $sep !~ /\S/ ) {
7023 $val = "1"; # this is an evil default; make 'em set it!
7026 # Separator is =. Trying to set a value.
7027 elsif ( $sep eq "=" ) {
7029 # If quoted, extract a quoted string.
7030 if ($s =~ s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
7032 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
7035 # Not quoted. Use the whole thing. Warn about 'option='.
7039 print OUT qq(Option better cleared using $opt=""\n)
7041 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
7043 } ## end elsif ($sep eq "=")
7045 # "Quoted" with [], <>, or {}.
7046 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
7048 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
7049 $s =~ s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
7050 or print( $OUT "Unclosed option value '$opt$sep$_'\n" ), last;
7051 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
7052 } ## end else [ if ("?" eq $sep)
7054 # Exclude non-booleans from getting set to 1 by default.
7055 if ( $opt_needs_val{$option} && $val_defaulted ) {
7056 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
7058 "Option '$opt' is non-boolean. Use '$cmd $option=VAL' to set, '$cmd $option?' to query\n";
7060 } ## end if ($opt_needs_val{$option...
7062 # Save the option value.
7063 $option{$option} = $val if defined $val;
7065 # Load any module that this option requires.
7066 if ( defined($optionRequire{$option}) && defined($val) ) {
7070 require '$optionRequire{$option}';
7072 } || die $@ # XXX: shouldn't happen
7076 # Stick it in the proper variable if it goes in a variable.
7077 if (defined($optionVars{$option}) && defined($val)) {
7078 ${ $optionVars{$option} } = $val;
7081 # Call the appropriate sub if it gets set via sub.
7082 if (defined($optionAction{$option})
7083 && defined (&{ $optionAction{$option} })
7086 &{ $optionAction{$option} }($val);
7089 # Not initialization - echo the value we set it to.
7090 dump_option($option) if ($OUT ne \*STDERR);
7091 } ## end while (length)
7092 } ## end sub parse_options
7094 =head1 RESTART SUPPORT
7096 These routines are used to store (and restore) lists of items in environment
7097 variables during a restart.
7101 Set_list packages up items to be stored in a set of environment variables
7102 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
7103 the values). Values outside the standard ASCII charset are stored by encoding
7104 then as hexadecimal values.
7109 my ( $stem, @list ) = @_;
7112 # VAR_n: how many we have. Scalar assignment gets the number of items.
7113 $ENV{"${stem}_n"} = @list;
7115 # Grab each item in the list, escape the backslashes, encode the non-ASCII
7116 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
7117 for my $i ( 0 .. $#list ) {
7119 $val =~ s/\\/\\\\/g;
7120 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
7121 $ENV{"${stem}_$i"} = $val;
7122 } ## end for $i (0 .. $#list)
7123 } ## end sub set_list
7127 Reverse the set_list operation: grab VAR_n to see how many we should be getting
7128 back, and then pull VAR_0, VAR_1. etc. back out.
7135 my $n = delete $ENV{"${stem}_n"};
7137 for my $i ( 0 .. $n - 1 ) {
7138 $val = delete $ENV{"${stem}_$i"};
7139 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
7143 } ## end sub get_list
7145 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
7149 The C<catch()> subroutine is the essence of fast and low-impact. We simply
7150 set an already-existing global scalar variable to a constant value. This
7151 avoids allocating any memory possibly in the middle of something that will
7152 get all confused if we do, particularly under I<unsafe signals>.
7158 return; # Put nothing on the stack - malloc/free land!
7163 C<warn> emits a warning, by joining together its arguments and printing
7164 them, with couple of fillips.
7166 If the composited message I<doesn't> end with a newline, we automatically
7167 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
7168 to be set to the filehandle to be used to output warnings; it makes no
7169 assumptions about what filehandles are available.
7174 my ($msg) = join( "", @_ );
7175 $msg .= ": $!\n" unless $msg =~ /\n$/;
7180 =head1 INITIALIZATION TTY SUPPORT
7182 =head2 C<reset_IN_OUT>
7184 This routine handles restoring the debugger's input and output filehandles
7185 after we've tried and failed to move them elsewhere. In addition, it assigns
7186 the debugger's output filehandle to $LINEINFO if it was already open there.
7191 my $switch_li = $LINEINFO eq $OUT;
7193 # If there's a term and it's able to get a new tty, try to get one.
7194 if ( $term and $term->Features->{newTTY} ) {
7195 ( $IN, $OUT ) = ( shift, shift );
7196 $term->newTTY( $IN, $OUT );
7199 # This term can't get a new tty now. Better luck later.
7201 &warn("Too late to set IN/OUT filehandles, enabled on next 'R'!\n");
7204 # Set the filehndles up as they were.
7206 ( $IN, $OUT ) = ( shift, shift );
7209 # Unbuffer the output filehandle.
7212 # Point LINEINFO to the same output filehandle if it was there before.
7213 $LINEINFO = $OUT if $switch_li;
7214 } ## end sub reset_IN_OUT
7216 =head1 OPTION SUPPORT ROUTINES
7218 The following routines are used to process some of the more complicated
7223 Sets the input and output filehandles to the specified files or pipes.
7224 If the terminal supports switching, we go ahead and do it. If not, and
7225 there's already a terminal in place, we save the information to take effect
7228 If there's no terminal yet (for instance, during debugger initialization),
7229 we go ahead and set C<$console> and C<$tty> to the file indicated.
7235 if ( @_ and $term and $term->Features->{newTTY} ) {
7237 # This terminal supports switching to a new TTY.
7238 # Can be a list of two files, or on string containing both names,
7240 # XXX Should this perhaps be an assignment from @_?
7241 my ( $in, $out ) = shift;
7244 # Split list apart if supplied.
7245 ( $in, $out ) = split /,/, $in, 2;
7249 # Use the same file for both input and output.
7253 # Open file onto the debugger's filehandles, if you can.
7254 open IN, $in or die "cannot open '$in' for read: $!";
7255 open OUT, ">$out" or die "cannot open '$out' for write: $!";
7257 # Swap to the new filehandles.
7258 reset_IN_OUT( \*IN, \*OUT );
7260 # Save the setting for later.
7262 } ## end if (@_ and $term and $term...
7264 # Terminal doesn't support new TTY, or doesn't support readline.
7265 # Can't do it now, try restarting.
7266 &warn("Too late to set TTY, enabled on next 'R'!\n") if $term and @_;
7268 # Useful if done through PERLDB_OPTS:
7269 $console = $tty = shift if @_;
7271 # Return whatever the TTY is.
7277 Sets the C<$notty> global, controlling whether or not the debugger tries to
7278 get a terminal to read from. If called after a terminal is already in place,
7279 we save the value to use it if we're restarted.
7285 &warn("Too late to set noTTY, enabled on next 'R'!\n") if @_;
7287 $notty = shift if @_;
7293 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
7294 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
7295 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
7296 the value in case a restart is done so we can change it then.
7302 &warn("Too late to set ReadLine, enabled on next 'R'!\n") if @_;
7306 } ## end sub ReadLine
7308 =head2 C<RemotePort>
7310 Sets the port that the debugger will try to connect to when starting up.
7311 If the terminal's already been set up, we can't do it, but we remember the
7312 setting in case the user does a restart.
7318 &warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
7320 $remoteport = shift if @_;
7322 } ## end sub RemotePort
7326 Checks with the terminal to see if C<Tk> is running, and returns true or
7327 false. Returns false if the current terminal doesn't support C<readline>.
7332 if ( ${ $term->Features }{tkRunning} ) {
7333 return $term->tkRunning(@_);
7337 print $OUT "tkRunning not supported by current ReadLine package.\n";
7340 } ## end sub tkRunning
7344 Sets nonstop mode. If a terminal's already been set up, it's too late; the
7345 debugger remembers the setting in case you restart, though.
7351 &warn("Too late to set up NonStop mode, enabled on next 'R'!\n")
7354 $runnonstop = shift if @_;
7356 } ## end sub NonStop
7360 &warn("Some flag changes could not take effect until next 'R'!\n")
7363 $^P = parse_DollarCaretP_flags(shift) if @_;
7364 expand_DollarCaretP_flags($^P);
7369 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
7377 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
7384 Sets the shell escape command, and generates a printable copy to be used
7391 # If we got an argument, meta-quote it, and add '\b' if it
7392 # ends in a word character.
7394 $sh = quotemeta shift;
7395 $sh .= "\\b" if $sh =~ /\w$/;
7398 # Generate the printable version for the help:
7399 $psh = $sh; # copy it
7400 $psh =~ s/\\b$//; # Take off trailing \b if any
7401 $psh =~ s/\\(.)/$1/g; # De-escape
7402 $psh; # return the printable version
7403 } ## end sub shellBang
7407 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7408 was passed as the argument. (This means you can't override the terminal's
7414 if ( defined $term ) {
7416 # We don't want to show warning backtraces, but we do want die() ones.
7417 local ( $warnLevel, $dieLevel ) = ( 0, 1 );
7419 # No ornaments if the terminal doesn't support them.
7420 return '' unless $term->Features->{ornaments};
7421 eval { $term->ornaments(@_) } || '';
7424 # Use what was passed in if we can't determine it ourselves.
7428 } ## end sub ornaments
7430 =head2 C<recallCommand>
7432 Sets the recall command, and builds a printable version which will appear in
7439 # If there is input, metaquote it. Add '\b' if it ends with a word
7442 $rc = quotemeta shift;
7443 $rc .= "\\b" if $rc =~ /\w$/;
7446 # Build it into a printable version.
7447 $prc = $rc; # Copy it
7448 $prc =~ s/\\b$//; # Remove trailing \b
7449 $prc =~ s/\\(.)/$1/g; # Remove escapes
7450 $prc; # Return the printable version
7451 } ## end sub recallCommand
7453 =head2 C<LineInfo> - where the line number information goes
7455 Called with no arguments, returns the file or pipe that line info should go to.
7457 Called with an argument (a file or a pipe), it opens that onto the
7458 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7459 file or pipe again to the caller.
7467 # If this is a valid "thing to be opened for output", tack a
7468 # '>' onto the front.
7469 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7471 # If this is a pipe, the stream points to a slave editor.
7472 $slave_editor = ( $stream =~ /^\|/ );
7474 # Open it up and unbuffer it.
7475 open( LINEINFO, $stream ) || &warn("Cannot open '$stream' for write");
7476 $LINEINFO = \*LINEINFO;
7477 $LINEINFO->autoflush(1);
7481 } ## end sub LineInfo
7483 =head1 COMMAND SUPPORT ROUTINES
7485 These subroutines provide functionality for various commands.
7487 =head2 C<list_modules>
7489 For the C<M> command: list modules loaded and their versions.
7490 Essentially just runs through the keys in %INC, picks each package's
7491 C<$VERSION> variable, gets the file name, and formats the information
7496 sub list_modules { # versions
7500 # keys are the "as-loaded" name, values are the fully-qualified path
7501 # to the file itself.
7503 $file = $_; # get the module name
7504 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
7505 s,/,::,g; # change '/' to '::'
7506 s/^perl5db$/DB/; # Special case: debugger
7507 # moves to package DB
7508 s/^Term::ReadLine::readline$/readline/; # simplify readline
7510 # If the package has a $VERSION package global (as all good packages
7511 # should!) decode it and save as partial message.
7512 my $pkg_version = do { no strict 'refs'; ${ $_ . '::VERSION' } };
7513 if ( defined $pkg_version ) {
7514 $version{$file} = "$pkg_version from ";
7517 # Finish up the message with the file the package came from.
7518 $version{$file} .= $INC{$file};
7519 } ## end for (keys %INC)
7521 # Hey, dumpit() formats a hash nicely, so why not use it?
7522 dumpit( $OUT, \%version );
7523 } ## end sub list_modules
7527 Sets up the monster string used to format and print the help.
7529 =head3 HELP MESSAGE FORMAT
7531 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
7532 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
7533 easy to parse and portable, but which still allows the help to be a little
7534 nicer than just plain text.
7536 Essentially, you define the command name (usually marked up with C<< B<> >>
7537 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
7538 newline. The descriptive text can also be marked up in the same way. If you
7539 need to continue the descriptive text to another line, start that line with
7540 just tabs and then enter the marked-up text.
7542 If you are modifying the help text, I<be careful>. The help-string parser is
7543 not very sophisticated, and if you don't follow these rules it will mangle the
7544 help beyond hope until you fix the string.
7548 use vars qw($pre580_help);
7549 use vars qw($pre580_summary);
7553 # XXX: make sure there are tabs between the command and explanation,
7554 # or print_help will screw up your formatting if you have
7555 # eeevil ornaments enabled. This is an insane mess.
7558 Help is currently only available for the new 5.8 command set.
7559 No help is available for the old command set.
7560 We assume you know what you're doing if you switch to it.
7563 B<s> [I<expr>] Single step [in I<expr>].
7564 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7565 <B<CR>> Repeat last B<n> or B<s> command.
7566 B<r> Return from current subroutine.
7567 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7568 at the specified position.
7569 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7570 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7571 B<l> I<line> List single I<line>.
7572 B<l> I<subname> List first window of lines from subroutine.
7573 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7574 B<l> List next window of lines.
7575 B<-> List previous window of lines.
7576 B<v> [I<line>] View window around I<line>.
7577 B<.> Return to the executed line.
7578 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7579 I<filename> may be either the full name of the file, or a regular
7580 expression matching the full file name:
7581 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7582 Evals (with saved bodies) are considered to be filenames:
7583 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7584 (in the order of execution).
7585 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7586 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7587 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
7588 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7589 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth).
7590 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
7591 B<b> Sets breakpoint on current line)
7592 B<b> [I<line>] [I<condition>]
7593 Set breakpoint; I<line> defaults to the current execution line;
7594 I<condition> breaks if it evaluates to true, defaults to '1'.
7595 B<b> I<subname> [I<condition>]
7596 Set breakpoint at first line of subroutine.
7597 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7598 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7599 B<b> B<postpone> I<subname> [I<condition>]
7600 Set breakpoint at first line of subroutine after
7602 B<b> B<compile> I<subname>
7603 Stop after the subroutine is compiled.
7604 B<B> [I<line>] Delete the breakpoint for I<line>.
7605 B<B> I<*> Delete all breakpoints.
7606 B<a> [I<line>] I<command>
7607 Set an action to be done before the I<line> is executed;
7608 I<line> defaults to the current execution line.
7609 Sequence is: check for breakpoint/watchpoint, print line
7610 if necessary, do action, prompt user if necessary,
7613 B<A> [I<line>] Delete the action for I<line>.
7614 B<A> I<*> Delete all actions.
7615 B<w> I<expr> Add a global watch-expression.
7617 B<W> I<expr> Delete a global watch-expression.
7618 B<W> I<*> Delete all watch-expressions.
7619 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7620 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7621 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7622 B<x> I<expr> Evals expression in list context, dumps the result.
7623 B<m> I<expr> Evals expression in list context, prints methods callable
7624 on the first element of the result.
7625 B<m> I<class> Prints methods callable via the given class.
7626 B<M> Show versions of loaded modules.
7627 B<i> I<class> Prints nested parents of given class.
7628 B<e> Display current thread id.
7629 B<E> Display all thread ids the current one will be identified: <n>.
7630 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7632 B<<> ? List Perl commands to run before each prompt.
7633 B<<> I<expr> Define Perl command to run before each prompt.
7634 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7635 B<< *> Delete the list of perl commands to run before each prompt.
7636 B<>> ? List Perl commands to run after each prompt.
7637 B<>> I<expr> Define Perl command to run after each prompt.
7638 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7639 B<>>B< *> Delete the list of Perl commands to run after each prompt.
7640 B<{> I<db_command> Define debugger command to run before each prompt.
7641 B<{> ? List debugger commands to run before each prompt.
7642 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7643 B<{ *> Delete the list of debugger commands to run before each prompt.
7644 B<$prc> I<number> Redo a previous command (default previous command).
7645 B<$prc> I<-number> Redo number'th-to-last command.
7646 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7647 See 'B<O> I<recallCommand>' too.
7648 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7653 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7655 See 'B<O> I<shellBang>' too.
7656 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7657 B<save> I<file> Save current debugger session (actual history) to I<file>.
7658 B<rerun> Rerun session to current position.
7659 B<rerun> I<n> Rerun session to numbered command.
7660 B<rerun> I<-n> Rerun session to number'th-to-last command.
7661 B<H> I<-number> Display last number commands (default all).
7662 B<H> I<*> Delete complete history.
7663 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7664 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7665 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarily select()ed as well.
7666 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7667 I<command> Execute as a perl statement in current package.
7668 B<R> Pure-man-restart of debugger, some of debugger state
7669 and command-line options may be lost.
7670 Currently the following settings are preserved:
7671 history, breakpoints and actions, debugger B<O>ptions
7672 and the following command-line options: I<-w>, I<-I>, I<-e>.
7674 B<o> [I<opt>] ... Set boolean option to true
7675 B<o> [I<opt>B<?>] Query options
7676 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7677 Set options. Use quotes if spaces in value.
7678 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7679 I<pager> program for output of \"|cmd\";
7680 I<tkRunning> run Tk while prompting (with ReadLine);
7681 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7682 I<inhibit_exit> Allows stepping off the end of the script.
7683 I<ImmediateStop> Debugger should stop as early as possible.
7684 I<RemotePort> Remote hostname:port for remote debugging
7685 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7686 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7687 I<compactDump>, I<veryCompact> change style of array and hash dump;
7688 I<globPrint> whether to print contents of globs;
7689 I<DumpDBFiles> dump arrays holding debugged files;
7690 I<DumpPackages> dump symbol tables of packages;
7691 I<DumpReused> dump contents of \"reused\" addresses;
7692 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7693 I<bareStringify> Do not print the overload-stringified value;
7694 Other options include:
7695 I<PrintRet> affects printing of return value after B<r> command,
7696 I<frame> affects printing messages on subroutine entry/exit.
7697 I<AutoTrace> affects printing messages on possible breaking points.
7698 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7699 I<ornaments> affects screen appearance of the command line.
7700 I<CreateTTY> bits control attempts to create a new TTY on events:
7701 1: on fork() 2: debugger is started inside debugger
7703 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7704 You can put additional initialization options I<TTY>, I<noTTY>,
7705 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7706 B<R> after you set them).
7708 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7709 B<h> Summary of debugger commands.
7710 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7711 B<h h> Long help for debugger commands
7712 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7713 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7714 Set B<\$DB::doccmd> to change viewer.
7716 Type '|h h' for a paged display if this was too hard to read.
7718 "; # Fix balance of vi % matching: }}}}
7720 # note: tabs in the following section are not-so-helpful
7721 $summary = <<"END_SUM";
7722 I<List/search source lines:> I<Control script execution:>
7723 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7724 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7725 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
7726 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7727 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7728 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
7729 I<Debugger controls:> B<L> List break/watch/actions
7730 B<o> [...] Set debugger options B<t> [I<n>] [I<expr>] Toggle trace [max depth] ][trace expr]
7731 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7732 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
7733 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7734 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
7735 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
7736 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
7737 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7738 B<q> or B<^D> Quit B<R> Attempt a restart
7739 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7740 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7741 B<p> I<expr> Print expression (uses script's current package).
7742 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7743 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7744 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
7745 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7746 B<e> Display thread id B<E> Display all thread ids.
7747 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7750 # ')}}; # Fix balance of vi % matching
7752 # and this is really numb...
7755 B<s> [I<expr>] Single step [in I<expr>].
7756 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7757 B<CR>> Repeat last B<n> or B<s> command.
7758 B<r> Return from current subroutine.
7759 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7760 at the specified position.
7761 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7762 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7763 B<l> I<line> List single I<line>.
7764 B<l> I<subname> List first window of lines from subroutine.
7765 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7766 B<l> List next window of lines.
7767 B<-> List previous window of lines.
7768 B<w> [I<line>] List window around I<line>.
7769 B<.> Return to the executed line.
7770 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7771 I<filename> may be either the full name of the file, or a regular
7772 expression matching the full file name:
7773 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7774 Evals (with saved bodies) are considered to be filenames:
7775 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7776 (in the order of execution).
7777 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7778 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7779 B<L> List all breakpoints and actions.
7780 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7781 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth) .
7782 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
7783 B<b> [I<line>] [I<condition>]
7784 Set breakpoint; I<line> defaults to the current execution line;
7785 I<condition> breaks if it evaluates to true, defaults to '1'.
7786 B<b> I<subname> [I<condition>]
7787 Set breakpoint at first line of subroutine.
7788 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7789 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7790 B<b> B<postpone> I<subname> [I<condition>]
7791 Set breakpoint at first line of subroutine after
7793 B<b> B<compile> I<subname>
7794 Stop after the subroutine is compiled.
7795 B<d> [I<line>] Delete the breakpoint for I<line>.
7796 B<D> Delete all breakpoints.
7797 B<a> [I<line>] I<command>
7798 Set an action to be done before the I<line> is executed;
7799 I<line> defaults to the current execution line.
7800 Sequence is: check for breakpoint/watchpoint, print line
7801 if necessary, do action, prompt user if necessary,
7803 B<a> [I<line>] Delete the action for I<line>.
7804 B<A> Delete all actions.
7805 B<W> I<expr> Add a global watch-expression.
7806 B<W> Delete all watch-expressions.
7807 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7808 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7809 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7810 B<x> I<expr> Evals expression in list context, dumps the result.
7811 B<m> I<expr> Evals expression in list context, prints methods callable
7812 on the first element of the result.
7813 B<m> I<class> Prints methods callable via the given class.
7815 B<<> ? List Perl commands to run before each prompt.
7816 B<<> I<expr> Define Perl command to run before each prompt.
7817 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7818 B<>> ? List Perl commands to run after each prompt.
7819 B<>> I<expr> Define Perl command to run after each prompt.
7820 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7821 B<{> I<db_command> Define debugger command to run before each prompt.
7822 B<{> ? List debugger commands to run before each prompt.
7823 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7824 B<$prc> I<number> Redo a previous command (default previous command).
7825 B<$prc> I<-number> Redo number'th-to-last command.
7826 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7827 See 'B<O> I<recallCommand>' too.
7828 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7833 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7835 See 'B<O> I<shellBang>' too.
7836 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7837 B<H> I<-number> Display last number commands (default all).
7838 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7839 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7840 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7841 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7842 I<command> Execute as a perl statement in current package.
7843 B<v> Show versions of loaded modules.
7844 B<R> Pure-man-restart of debugger, some of debugger state
7845 and command-line options may be lost.
7846 Currently the following settings are preserved:
7847 history, breakpoints and actions, debugger B<O>ptions
7848 and the following command-line options: I<-w>, I<-I>, I<-e>.
7850 B<O> [I<opt>] ... Set boolean option to true
7851 B<O> [I<opt>B<?>] Query options
7852 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7853 Set options. Use quotes if spaces in value.
7854 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7855 I<pager> program for output of \"|cmd\";
7856 I<tkRunning> run Tk while prompting (with ReadLine);
7857 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7858 I<inhibit_exit> Allows stepping off the end of the script.
7859 I<ImmediateStop> Debugger should stop as early as possible.
7860 I<RemotePort> Remote hostname:port for remote debugging
7861 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7862 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7863 I<compactDump>, I<veryCompact> change style of array and hash dump;
7864 I<globPrint> whether to print contents of globs;
7865 I<DumpDBFiles> dump arrays holding debugged files;
7866 I<DumpPackages> dump symbol tables of packages;
7867 I<DumpReused> dump contents of \"reused\" addresses;
7868 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7869 I<bareStringify> Do not print the overload-stringified value;
7870 Other options include:
7871 I<PrintRet> affects printing of return value after B<r> command,
7872 I<frame> affects printing messages on subroutine entry/exit.
7873 I<AutoTrace> affects printing messages on possible breaking points.
7874 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7875 I<ornaments> affects screen appearance of the command line.
7876 I<CreateTTY> bits control attempts to create a new TTY on events:
7877 1: on fork() 2: debugger is started inside debugger
7879 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7880 You can put additional initialization options I<TTY>, I<noTTY>,
7881 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7882 B<R> after you set them).
7884 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7885 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7886 B<h h> Summary of debugger commands.
7887 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7888 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7889 Set B<\$DB::doccmd> to change viewer.
7891 Type '|h' for a paged display if this was too hard to read.
7893 "; # Fix balance of vi % matching: }}}}
7895 # note: tabs in the following section are not-so-helpful
7896 $pre580_summary = <<"END_SUM";
7897 I<List/search source lines:> I<Control script execution:>
7898 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7899 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7900 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
7901 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7902 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7903 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
7904 I<Debugger controls:> B<L> List break/watch/actions
7905 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7906 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7907 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
7908 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7909 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
7910 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
7911 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7912 B<q> or B<^D> Quit B<R> Attempt a restart
7913 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7914 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7915 B<p> I<expr> Print expression (uses script's current package).
7916 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7917 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7918 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
7919 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7920 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7923 # ')}}; # Fix balance of vi % matching
7925 } ## end sub sethelp
7927 =head2 C<print_help()>
7929 Most of what C<print_help> does is just text formatting. It finds the
7930 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
7931 terminal control characters to simulate them (courtesy of
7932 C<Term::ReadLine::TermCap>).
7937 my $help_str = shift;
7939 # Restore proper alignment destroyed by eeevil I<> and B<>
7940 # ornaments: A pox on both their houses!
7942 # A help command will have everything up to and including
7943 # the first tab sequence padded into a field 16 (or if indented 20)
7944 # wide. If it's wider than that, an extra space will be added.
7946 ^ # only matters at start of line
7947 ( \040{4} | \t )* # some subcommands are indented
7948 ( < ? # so <CR> works
7949 [BI] < [^\t\n] + ) # find an eeevil ornament
7950 ( \t+ ) # original separation, discarded
7951 ( .* ) # this will now start (no earlier) than
7954 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
7955 my $clean = $command;
7956 $clean =~ s/[BI]<([^>]*)>/$1/g;
7958 # replace with this whole string:
7959 ($leadwhite ? " " x 4 : "")
7961 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
7966 $help_str =~ s{ # handle bold ornaments
7967 B < ( [^>] + | > ) >
7969 $Term::ReadLine::TermCap::rl_term_set[2]
7971 . $Term::ReadLine::TermCap::rl_term_set[3]
7974 $help_str =~ s{ # handle italic ornaments
7975 I < ( [^>] + | > ) >
7977 $Term::ReadLine::TermCap::rl_term_set[0]
7979 . $Term::ReadLine::TermCap::rl_term_set[1]
7983 print {$OUT} $help_str;
7986 } ## end sub print_help
7990 This routine does a lot of gyrations to be sure that the pager is C<less>.
7991 It checks for C<less> masquerading as C<more> and records the result in
7992 C<$fixed_less> so we don't have to go through doing the stats again.
7996 use vars qw($fixed_less);
7999 if ($pager =~ /\bless\b/)
8003 elsif ($pager =~ /\bmore\b/)
8005 # Nope, set to more. See what's out there.
8006 my @st_more = stat('/usr/bin/more');
8007 my @st_less = stat('/usr/bin/less');
8009 # is it really less, pretending to be more?
8013 && $st_more[0] == $st_less[0]
8014 && $st_more[1] == $st_less[1]
8024 # We already know if this is set.
8025 return if $fixed_less;
8027 # changes environment!
8028 # 'r' added so we don't do (slow) stats again.
8029 $fixed_less = 1 if _calc_is_less();
8032 } ## end sub fix_less
8034 =head1 DIE AND WARN MANAGEMENT
8038 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
8039 to debug a debugger problem.
8041 It does its best to report the error that occurred, and then forces the
8042 program, debugger, and everything to die.
8048 # No entry/exit messages.
8051 # No return value prints.
8054 # set the abort signal handling to the default (just terminate).
8055 $SIG{'ABRT'} = 'DEFAULT';
8057 # If we enter the signal handler recursively, kill myself with an
8058 # abort signal (so we just terminate).
8059 kill 'ABRT', $$ if $panic++;
8061 # If we can show detailed info, do so.
8062 if ( defined &Carp::longmess ) {
8064 # Don't recursively enter the warn handler, since we're carping.
8065 local $SIG{__WARN__} = '';
8067 # Skip two levels before reporting traceback: we're skipping
8068 # mydie and confess.
8069 local $Carp::CarpLevel = 2; # mydie + confess
8071 # Tell us all about it.
8072 &warn( Carp::longmess("Signal @_") );
8075 # No Carp. Tell us about the signal as best we can.
8078 print $DB::OUT "Got signal @_\n";
8083 } ## end sub diesignal
8087 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
8088 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
8094 # No entry/exit trace.
8097 # No return value printing.
8100 # Turn off warn and die handling to prevent recursive entries to this
8102 local $SIG{__WARN__} = '';
8103 local $SIG{__DIE__} = '';
8105 # Load Carp if we can. If $^S is false (current thing being compiled isn't
8106 # done yet), we may not be able to do a require.
8107 eval { require Carp }
8108 if defined $^S; # If error/warning during compilation,
8109 # require may be broken.
8111 # Use the core warn() unless Carp loaded OK.
8113 "\nCannot print stack trace, load with -MCarp option to see stack" ),
8115 unless defined &Carp::longmess;
8117 # Save the current values of $single and $trace, and then turn them off.
8118 my ( $mysingle, $mytrace ) = ( $single, $trace );
8122 # We can call Carp::longmess without its being "debugged" (which we
8123 # don't want - we just want to use it!). Capture this for later.
8124 my $mess = Carp::longmess(@_);
8126 # Restore $single and $trace to their original values.
8127 ( $single, $trace ) = ( $mysingle, $mytrace );
8129 # Use the debugger's own special way of printing warnings to print
8130 # the stack trace message.
8136 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
8137 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
8138 single stepping and tracing during the call to C<Carp::longmess> to avoid
8139 debugging it - we just want to use it.
8141 If C<dieLevel> is zero, we let the program being debugged handle the
8142 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
8143 the debugger takes over all exception handling, printing a backtrace and
8144 displaying the exception via its C<dbwarn()> routine.
8151 local $SIG{__DIE__} = '';
8152 local $SIG{__WARN__} = '';
8156 if ( $dieLevel > 2 ) {
8157 local $SIG{__WARN__} = \&dbwarn;
8158 &warn(@_); # Yell no matter what
8161 if ( $dieLevel < 2 ) {
8162 die @_ if $^S; # in eval propagate
8165 # The code used to check $^S to see if compilation of the current thing
8166 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
8167 eval { require Carp };
8170 "\nCannot print stack trace, load with -MCarp option to see stack" )
8171 unless defined &Carp::longmess;
8173 # We do not want to debug this chunk (automatic disabling works
8174 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
8175 # get the stack trace from Carp::longmess (if possible), restore $signal
8176 # and $trace, and then die with the stack trace.
8177 my ( $mysingle, $mytrace ) = ( $single, $trace );
8183 package Carp; # Do not include us in the list
8184 eval { $mess = Carp::longmess(@_); };
8186 ( $single, $trace ) = ( $mysingle, $mytrace );
8190 =head2 C<warnlevel()>
8192 Set the C<$DB::warnLevel> variable that stores the value of the
8193 C<warnLevel> option. Calling C<warnLevel()> with a positive value
8194 results in the debugger taking over all warning handlers. Setting
8195 C<warnLevel> to zero leaves any warning handlers set up by the program
8196 being debugged in place.
8202 my $prevwarn = $SIG{__WARN__} unless $warnLevel;
8205 $SIG{__WARN__} = \&DB::dbwarn;
8208 $SIG{__WARN__} = $prevwarn;
8210 undef $SIG{__WARN__};
8214 } ## end sub warnLevel
8218 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
8219 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
8220 zero lets you use your own C<die()> handler.
8227 my $prevdie = $SIG{__DIE__} unless $dieLevel;
8231 # Always set it to dbdie() for non-zero values.
8232 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
8234 # No longer exists, so don't try to use it.
8235 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
8237 # If we've finished initialization, mention that stack dumps
8238 # are enabled, If dieLevel is 1, we won't stack dump if we die
8240 print $OUT "Stack dump during die enabled",
8241 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
8244 # XXX This is probably obsolete, given that diehard() is gone.
8245 print $OUT "Dump printed too.\n" if $dieLevel > 2;
8246 } ## end if ($dieLevel)
8248 # Put the old one back if there was one.
8250 $SIG{__DIE__} = $prevdie;
8251 print $OUT "Default die handler restored.\n";
8253 undef $SIG{__DIE__};
8254 print $OUT "Die handler removed.\n";
8258 } ## end sub dieLevel
8260 =head2 C<signalLevel>
8262 Number three in a series: set C<signalLevel> to zero to keep your own
8263 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
8264 takes over and handles them with C<DB::diesignal()>.
8270 my $prevsegv = $SIG{SEGV} unless $signalLevel;
8271 my $prevbus = $SIG{BUS} unless $signalLevel;
8272 $signalLevel = shift;
8274 $SIG{SEGV} = \&DB::diesignal;
8275 $SIG{BUS} = \&DB::diesignal;
8278 $SIG{SEGV} = $prevsegv;
8279 $SIG{BUS} = $prevbus;
8283 } ## end sub signalLevel
8285 =head1 SUBROUTINE DECODING SUPPORT
8287 These subroutines are used during the C<x> and C<X> commands to try to
8288 produce as much information as possible about a code reference. They use
8289 L<Devel::Peek> to try to find the glob in which this code reference lives
8290 (if it does) - this allows us to actually code references which correspond
8291 to named subroutines (including those aliased via glob assignment).
8293 =head2 C<CvGV_name()>
8295 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
8296 via that routine. If this fails, return the reference again (when the
8297 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
8303 my $name = CvGV_name_or_bust($in);
8304 defined $name ? $name : $in;
8307 =head2 C<CvGV_name_or_bust> I<coderef>
8309 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
8310 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
8311 find a glob for this ref.
8313 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
8317 use vars qw($skipCvGV);
8319 sub CvGV_name_or_bust {
8321 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
8322 return unless ref $in;
8323 $in = \&$in; # Hard reference...
8324 eval { require Devel::Peek; 1 } or return;
8325 my $gv = Devel::Peek::CvGV($in) or return;
8326 *$gv{PACKAGE} . '::' . *$gv{NAME};
8327 } ## end sub CvGV_name_or_bust
8331 A utility routine used in various places; finds the file where a subroutine
8332 was defined, and returns that filename and a line-number range.
8334 Tries to use C<@sub> first; if it can't find it there, it tries building a
8335 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
8336 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
8337 this way, it brute-force searches C<%sub>, checking for identical references.
8341 sub _find_sub_helper {
8344 return unless defined &$subr;
8345 my $name = CvGV_name_or_bust($subr);
8347 $data = $sub{$name} if defined $name;
8348 return $data if defined $data;
8351 $subr = \&$subr; # Hard reference
8354 $s = $_, last if $subr eq \&$_;
8369 return ( $sub{$subr} || _find_sub_helper($subr) );
8370 } ## end sub find_sub
8374 A subroutine that uses the utility function C<methods_via> to find all the
8375 methods in the class corresponding to the current reference and in
8384 # Figure out the class - either this is the class or it's a reference
8385 # to something blessed into that class.
8387 $class = ref $class if ref $class;
8391 # Show the methods that this class has.
8392 methods_via( $class, '', 1 );
8394 # Show the methods that UNIVERSAL has.
8395 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
8396 } ## end sub methods
8398 =head2 C<methods_via($class, $prefix, $crawl_upward)>
8400 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
8401 all the parent class methods. C<$class> is the name of the next class to
8402 try; C<$prefix> is the message prefix, which gets built up as we go up the
8403 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
8404 higher in the C<@ISA> tree, 0 if we should stop.
8410 # If we've processed this class already, just quit.
8412 return if $seen{$class}++;
8414 # This is a package that is contributing the methods we're about to print.
8416 my $prepend = $prefix ? "via $prefix: " : '';
8419 # Extract from all the symbols in this class.
8420 my $class_ref = do { no strict "refs"; \%{$class . '::'} };
8421 while (my ($name, $glob) = each %$class_ref) {
8422 # references directly in the symbol table are Proxy Constant
8423 # Subroutines, and are by their very nature defined
8424 # Otherwise, check if the thing is a typeglob, and if it is, it decays
8425 # to a subroutine reference, which can be tested by defined.
8426 # $glob might also be the value -1 (from sub foo;)
8427 # or (say) '$$' (from sub foo ($$);)
8428 # \$glob will be SCALAR in both cases.
8429 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob))
8430 && !$seen{$name}++) {
8431 push @to_print, "$prepend$name\n";
8438 print $DB::OUT $_ foreach sort @to_print;
8441 # If the $crawl_upward argument is false, just quit here.
8442 return unless shift;
8444 # $crawl_upward true: keep going up the tree.
8445 # Find all the classes this one is a subclass of.
8446 my $class_ISA_ref = do { no strict "refs"; \@{"${class}::ISA"} };
8447 for my $name ( @$class_ISA_ref ) {
8449 # Set up the new prefix.
8450 $prepend = $prefix ? $prefix . " -> $name" : $name;
8452 # Crawl up the tree and keep trying to crawl up.
8453 methods_via( $name, $prepend, 1 );
8455 } ## end sub methods_via
8457 =head2 C<setman> - figure out which command to use to show documentation
8459 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8464 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|NetWare)\z/s
8465 ? "man" # O Happy Day!
8466 : "perldoc"; # Alas, poor unfortunates
8469 =head2 C<runman> - run the appropriate command to show documentation
8471 Accepts a man page name; runs the appropriate command to display it (set up
8472 during debugger initialization). Uses C<DB::system> to avoid mucking up the
8473 program's STDIN and STDOUT.
8477 my %_is_in_pods = (map { $_ => 1 }
8615 &system("$doccmd $doccmd");
8619 # this way user can override, like with $doccmd="man -Mwhatever"
8620 # or even just "man " to disable the path check.
8621 unless ( $doccmd eq 'man' ) {
8622 &system("$doccmd $page");
8626 $page = 'perl' if lc($page) eq 'help';
8629 my $man1dir = $Config::Config{'man1dir'};
8630 my $man3dir = $Config::Config{'man3dir'};
8631 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
8633 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
8634 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
8635 chop $manpath if $manpath;
8637 # harmless if missing, I figure
8638 my $oldpath = $ENV{MANPATH};
8639 $ENV{MANPATH} = $manpath if $manpath;
8640 my $nopathopt = $^O =~ /dunno what goes here/;
8645 # I just *know* there are men without -M
8646 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8651 unless ( $page =~ /^perl\w/ ) {
8652 # do it this way because its easier to slurp in to keep up to date - clunky though.
8653 if (exists($_is_in_pods{$page})) {
8654 CORE::system( $doccmd,
8655 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8659 } ## end if (CORE::system($doccmd...
8660 if ( defined $oldpath ) {
8661 $ENV{MANPATH} = $manpath;
8664 delete $ENV{MANPATH};
8668 #use Carp; # This did break, left for debugging
8670 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
8672 Because of the way the debugger interface to the Perl core is designed, any
8673 debugger package globals that C<DB::sub()> requires have to be defined before
8674 any subroutines can be called. These are defined in the second C<BEGIN> block.
8676 This block sets things up so that (basically) the world is sane
8677 before the debugger starts executing. We set up various variables that the
8678 debugger has to have set up before the Perl core starts running:
8684 The debugger's own filehandles (copies of STD and STDOUT for now).
8688 Characters for shell escapes, the recall command, and the history command.
8692 The maximum recursion depth.
8696 The size of a C<w> command's window.
8700 The before-this-line context to be printed in a C<v> (view a window around this line) command.
8704 The fact that we're not in a sub at all right now.
8708 The default SIGINT handler for the debugger.
8712 The appropriate value of the flag in C<$^D> that says the debugger is running
8716 The current debugger recursion level
8720 The list of postponed items and the C<$single> stack (XXX define this)
8724 That we want no return values and no subroutine entry/exit trace.
8730 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
8732 use vars qw($db_stop);
8734 BEGIN { # This does not compile, alas. (XXX eh?)
8735 $IN = \*STDIN; # For bugs before DB::OUT has been opened
8736 $OUT = \*STDERR; # For errors before DB::OUT has been opened
8738 # Define characters used by command parsing.
8739 $sh = '!'; # Shell escape (does not work)
8740 $rc = ','; # Recall command (does not work)
8741 @hist = ('?'); # Show history (does not work)
8742 @truehist = (); # Can be saved for replay (per session)
8744 # This defines the point at which you get the 'deep recursion'
8745 # warning. It MUST be defined or the debugger will not load.
8748 # Number of lines around the current one that are shown in the
8752 # How much before-the-current-line context the 'v' command should
8753 # use in calculating the start of the window it will display.
8756 # We're not in any sub yet, but we need this to be a defined value.
8759 # Set up the debugger's interrupt handler. It simply sets a flag
8760 # ($signal) that DB::DB() will check before each command is executed.
8761 $SIG{INT} = \&DB::catch;
8763 # The following lines supposedly, if uncommented, allow the debugger to
8764 # debug itself. Perhaps we can try that someday.
8765 # This may be enabled to debug debugger:
8766 #$warnLevel = 1 unless defined $warnLevel;
8767 #$dieLevel = 1 unless defined $dieLevel;
8768 #$signalLevel = 1 unless defined $signalLevel;
8770 # This is the flag that says "a debugger is running, please call
8771 # DB::DB and DB::sub". We will turn it on forcibly before we try to
8772 # execute anything in the user's context, because we always want to
8774 $db_stop = 0; # Compiler warning ...
8775 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
8777 # This variable records how many levels we're nested in debugging. Used
8778 # Used in the debugger prompt, and in determining whether it's all over or
8780 $level = 0; # Level of recursive debugging
8782 # "Triggers bug (?) in perl if we postpone this until runtime."
8783 # XXX No details on this yet, or whether we should fix the bug instead
8784 # of work around it. Stay tuned.
8787 # Used to track the current stack depth using the auto-stacked-variable
8789 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
8791 # Don't print return values on exiting a subroutine.
8794 # No extry/exit tracing.
8799 BEGIN { $^W = $ini_warn; } # Switch warnings back
8801 =head1 READLINE SUPPORT - COMPLETION FUNCTION
8805 C<readline> support - adds command completion to basic C<readline>.
8807 Returns a list of possible completions to C<readline> when invoked. C<readline>
8808 will print the longest common substring following the text already entered.
8810 If there is only a single possible completion, C<readline> will use it in full.
8812 This code uses C<map> and C<grep> heavily to create lists of possible
8813 completion. Think LISP in this section.
8819 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
8820 # $text is the text to be completed.
8821 # $line is the incoming line typed by the user.
8822 # $start is the start of the text to be completed in the incoming line.
8823 my ( $text, $line, $start ) = @_;
8825 # Save the initial text.
8826 # The search pattern is current package, ::, extract the next qualifier
8827 # Prefix and pack are set to undef.
8828 my ( $itext, $search, $prefix, $pack ) =
8829 ( $text, "^\Q${package}::\E([^:]+)\$" );
8831 =head3 C<b postpone|compile>
8837 Find all the subroutines that might match in this package
8841 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
8845 Include all the rest of the subs that are known
8849 C<grep> out the ones that match the text we have so far
8853 Return this as the list of possible completions
8859 return sort grep /^\Q$text/, ( keys %sub ),
8860 qw(postpone load compile), # subroutines
8861 ( map { /$search/ ? ($1) : () } keys %sub )
8862 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
8866 Get all the possible files from C<@INC> as it currently stands and
8867 select the ones that match the text so far.
8871 return sort grep /^\Q$text/, values %INC # files
8872 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
8874 =head3 C<V> (list variable) and C<m> (list modules)
8876 There are two entry points for these commands:
8878 =head4 Unqualified package names
8880 Get the top-level packages and grab everything that matches the text
8881 so far. For each match, recursively complete the partial packages to
8882 get all possible matching packages. Return this sorted list.
8886 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8887 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
8888 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
8890 =head4 Qualified package names
8892 Take a partially-qualified package and find all subpackages for it
8893 by getting all the subpackages for the package so far, matching all
8894 the subpackages against the text, and discarding all of them which
8895 start with 'main::'. Return this list.
8899 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8900 grep !/^main::/, grep /^\Q$text/,
8901 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () }
8902 do { no strict 'refs'; keys %{ $prefix . '::' } }
8903 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
8904 and $text =~ /^(.*[^:])::?(\w*)$/
8907 =head3 C<f> - switch files
8909 Here, we want to get a fully-qualified filename for the C<f> command.
8914 =item 1. The original source file itself
8916 =item 2. A file from C<@INC>
8918 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
8924 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
8925 # We might possibly want to switch to an eval (which has a "filename"
8926 # like '(eval 9)'), so we may need to clean up the completion text
8927 # before proceeding.
8928 $prefix = length($1) - length($text);
8933 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
8934 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
8935 out of C<%main::>, add the initial source file, and extract the ones that
8936 match the completion text so far.
8941 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
8943 } ## end if ($line =~ /^\|*f\s+(.*)/)
8945 =head3 Subroutine name completion
8947 We look through all of the defined subs (the keys of C<%sub>) and
8948 return both all the possible matches to the subroutine name plus
8949 all the matches qualified to the current package.
8953 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
8954 $text = substr $text, 1;
8956 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
8958 map { /$search/ ? ($1) : () }
8961 } ## end if ((substr $text, 0, ...
8963 =head3 Scalar, array, and hash completion: partially qualified package
8965 Much like the above, except we have to do a little more cleanup:
8969 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
8977 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
8981 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
8987 Figure out the prefix vs. what needs completing.
8991 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
8998 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
9004 map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
9012 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.
9016 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9017 return db_complete( $out[0], $line, $start );
9020 # Return the list of possibles.
9023 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
9029 =head3 Symbol completion: current package or package C<main>.
9033 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
9040 If it's C<main>, delete main to just get C<::> leading.
9044 $pack = ( $package eq 'main' ? '' : $package ) . '::';
9050 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
9054 $prefix = substr $text, 0, 1;
9055 $text = substr $text, 1;
9063 We look for the lexical scope above DB::DB and auto-complete lexical variables
9064 if PadWalker could be loaded.
9068 if (not $text =~ /::/ and eval { require PadWalker } ) {
9071 my @info = caller($level);
9075 last if $info[3] eq 'DB::DB';
9078 my $lexicals = PadWalker::peek_my($level);
9079 push @out, grep /^\Q$prefix$text/, keys %$lexicals;
9087 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
9091 push @out, map "$prefix$_", grep /^\Q$text/,
9092 ( grep /^_?[a-zA-Z]/, keys %$pack ),
9093 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
9097 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
9103 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9104 return db_complete( $out[0], $line, $start );
9107 # Return the list of possibles.
9109 } ## end if ($text =~ /^[\$@%]/)
9113 We use C<option_val()> to look up the current value of the option. If there's
9114 only a single value, we complete the command in such a way that it is a
9115 complete command for setting the option in question. If there are multiple
9116 possible values, we generate a command consisting of the option plus a trailing
9117 question mark, which, if executed, will list the current value of the option.
9121 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
9122 { # Options after space
9123 # We look for the text to be matched in the list of possible options,
9124 # and fetch the current value.
9125 my @out = grep /^\Q$text/, @options;
9126 my $val = option_val( $out[0], undef );
9128 # Set up a 'query option's value' command.
9130 if ( not defined $val or $val =~ /[\n\r]/ ) {
9132 # There's really nothing else we can do.
9135 # We have a value. Create a proper option-setting command.
9136 elsif ( $val =~ /\s/ ) {
9138 # XXX This may be an extraneous variable.
9141 # We'll want to quote the string (because of the embedded
9142 # whtespace), but we want to make sure we don't end up with
9143 # mismatched quote characters. We try several possibilities.
9144 foreach my $l ( split //, qq/\"\'\#\|/ ) {
9146 # If we didn't find this quote character in the value,
9147 # quote it using this quote character.
9148 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
9150 } ## end elsif ($val =~ /\s/)
9152 # Don't need any quotes.
9157 # If there were multiple possible values, return '? ', which
9158 # makes the command into a query command. If there was just one,
9159 # have readline append that.
9160 $rl_attribs->{completer_terminator_character} =
9161 ( @out == 1 ? $out : '? ' );
9163 # Return list of possibilities.
9165 } ## end if ((substr $line, 0, ...
9167 =head3 Filename completion
9169 For entering filenames. We simply call C<readline>'s C<filename_list()>
9170 method with the completion text to get the possible completions.
9174 return $term->filename_list($text); # filenames
9176 } ## end sub db_complete
9178 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
9180 Functions that possibly ought to be somewhere else.
9190 print $OUT "Use 'q' to quit or 'R' to restart. 'h q' for details.\n";
9195 If we have $ini_pids, save it in the environment; else remove it from the
9196 environment. Used by the C<R> (restart) command.
9201 if ( defined($ini_pids) ) {
9202 $ENV{PERLDB_PIDS} = $ini_pids;
9205 delete( $ENV{PERLDB_PIDS} );
9207 } ## end sub clean_ENV
9209 # PERLDBf_... flag names from perl.h
9210 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
9213 %DollarCaretP_flags = (
9214 PERLDBf_SUB => 0x01, # Debug sub enter/exit
9215 PERLDBf_LINE => 0x02, # Keep line #
9216 PERLDBf_NOOPT => 0x04, # Switch off optimizations
9217 PERLDBf_INTER => 0x08, # Preserve more data
9218 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
9219 PERLDBf_SINGLE => 0x20, # Start with single-step on
9220 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
9221 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
9222 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
9223 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
9224 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"}
9225 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO
9227 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger
9228 # doesn't need to set it. It's provided for the benefit of profilers and
9229 # other code analysers.
9231 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
9234 sub parse_DollarCaretP_flags {
9239 foreach my $f ( split /\s*\|\s*/, $flags ) {
9241 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
9244 elsif ( $f =~ /^(\d+)$/ ) {
9247 elsif ( $f =~ /^DEFAULT$/i ) {
9248 $value = $DollarCaretP_flags{PERLDB_ALL};
9251 $f =~ /^(?:PERLDBf_)?(.*)$/i;
9252 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
9253 unless ( defined $value ) {
9255 "Unrecognized \$^P flag '$f'!\n",
9256 "Acceptable flags are: "
9257 . join( ', ', sort keys %DollarCaretP_flags ),
9258 ", and hexadecimal and decimal numbers.\n"
9268 sub expand_DollarCaretP_flags {
9269 my $DollarCaretP = shift;
9272 my $n = ( 1 << $_ );
9273 ( $DollarCaretP & $n )
9274 ? ( $DollarCaretP_flags_r{$n}
9275 || sprintf( '0x%x', $n ) )
9279 return @bits ? join( '|', @bits ) : 0;
9286 Rerun the current session to:
9288 rerun current position
9290 rerun 4 command number 4
9292 rerun -4 current command minus 4 (go back 4 steps)
9294 Whether this always makes sense, in the current context is unknowable, and is
9295 in part left as a useful exercise for the reader. This sub returns the
9296 appropriate arguments to rerun the current session.
9303 pop(@truehist); # strim
9304 unless (defined $truehist[$i]) {
9305 print "Unable to return to non-existent command: $i\n";
9307 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
9308 my @temp = @truehist; # store
9309 push(@DB::typeahead, @truehist); # saved
9310 @truehist = @hist = (); # flush
9311 @args = &restart(); # setup
9312 &get_list("PERLDB_HIST"); # clean
9313 &set_list("PERLDB_HIST", @temp); # reset
9320 Restarting the debugger is a complex operation that occurs in several phases.
9321 First, we try to reconstruct the command line that was used to invoke Perl
9327 # I may not be able to resurrect you, but here goes ...
9329 "Warning: some settings and command-line options may be lost!\n";
9330 my ( @script, @flags, $cl );
9332 # If warn was on before, turn it on again.
9333 push @flags, '-w' if $ini_warn;
9335 # Rebuild the -I flags that were on the initial
9338 push @flags, '-I', $_;
9341 # Turn on taint if it was on before.
9342 push @flags, '-T' if ${^TAINT};
9344 # Arrange for setting the old INC:
9345 # Save the current @init_INC in the environment.
9346 set_list( "PERLDB_INC", @ini_INC );
9348 # If this was a perl one-liner, go to the "file"
9349 # corresponding to the one-liner read all the lines
9350 # out of it (except for the first one, which is going
9351 # to be added back on again when 'perl -d' runs: that's
9352 # the 'require perl5db.pl;' line), and add them back on
9353 # to the command line to be executed.
9355 my $lines = *{$main::{'_<-e'}}{ARRAY};
9356 for ( 1 .. $#$lines ) { # The first line is PERL5DB
9357 chomp( $cl = $lines->[$_] );
9358 push @script, '-e', $cl;
9360 } ## end if ($0 eq '-e')
9362 # Otherwise we just reuse the original name we had
9370 After the command line has been reconstructed, the next step is to save
9371 the debugger's status in environment variables. The C<DB::set_list> routine
9372 is used to save aggregate variables (both hashes and arrays); scalars are
9373 just popped into environment variables directly.
9377 # If the terminal supported history, grab it and
9378 # save that in the environment.
9379 set_list( "PERLDB_HIST",
9380 $term->Features->{getHistory}
9384 # Find all the files that were visited during this
9385 # session (i.e., the debugger had magic hashes
9386 # corresponding to them) and stick them in the environment.
9387 my @had_breakpoints = keys %had_breakpoints;
9388 set_list( "PERLDB_VISITED", @had_breakpoints );
9390 # Save the debugger options we chose.
9391 set_list( "PERLDB_OPT", %option );
9392 # set_list( "PERLDB_OPT", options2remember() );
9394 # Save the break-on-loads.
9395 set_list( "PERLDB_ON_LOAD", %break_on_load );
9399 The most complex part of this is the saving of all of the breakpoints. They
9400 can live in an awful lot of places, and we have to go through all of them,
9401 find the breakpoints, and then save them in the appropriate environment
9402 variable via C<DB::set_list>.
9406 # Go through all the breakpoints and make sure they're
9409 for ( 0 .. $#had_breakpoints ) {
9411 # We were in this file.
9412 my $file = $had_breakpoints[$_];
9414 # Grab that file's magic line hash.
9415 *dbline = $main::{ '_<' . $file };
9417 # Skip out if it doesn't exist, or if the breakpoint
9418 # is in a postponed file (we'll do postponed ones
9420 next unless %dbline or $postponed_file{$file};
9422 # In an eval. This is a little harder, so we'll
9423 # do more processing on that below.
9424 ( push @hard, $file ), next
9425 if $file =~ /^\(\w*eval/;
9427 # XXX I have no idea what this is doing. Yet.
9429 @add = %{ $postponed_file{$file} }
9430 if $postponed_file{$file};
9432 # Save the list of all the breakpoints for this file.
9433 set_list( "PERLDB_FILE_$_", %dbline, @add );
9435 # Serialize the extra data %breakpoints_data hash.
9437 set_list( "PERLDB_FILE_ENABLED_$_",
9438 map { _is_breakpoint_enabled($file, $_) ? 1 : 0 }
9439 sort { $a <=> $b } keys(%dbline)
9441 } ## end for (0 .. $#had_breakpoints)
9443 # The breakpoint was inside an eval. This is a little
9444 # more difficult. XXX and I don't understand it.
9446 # Get over to the eval in question.
9447 *dbline = $main::{ '_<' . $_ };
9448 my ( $quoted, $sub, %subs, $line ) = quotemeta $_;
9449 for $sub ( keys %sub ) {
9450 next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/;
9451 $subs{$sub} = [ $1, $2 ];
9455 "No subroutines in $_, ignoring breakpoints.\n";
9458 LINES: for $line ( keys %dbline ) {
9460 # One breakpoint per sub only:
9461 my ( $offset, $sub, $found );
9462 SUBS: for $sub ( keys %subs ) {
9465 $line # Not after the subroutine
9467 not defined $offset # Not caught
9473 $offset = $line - $subs{$sub}->[0];
9474 $offset = "+$offset", last SUBS
9476 } ## end if ($subs{$sub}->[1] >=...
9477 } ## end for $sub (keys %subs)
9478 if ( defined $offset ) {
9479 $postponed{$found} =
9480 "break $offset if $dbline{$line}";
9484 "Breakpoint in $_:$line ignored: after all the subroutines.\n";
9486 } ## end for $line (keys %dbline)
9487 } ## end for (@hard)
9489 # Save the other things that don't need to be
9491 set_list( "PERLDB_POSTPONE", %postponed );
9492 set_list( "PERLDB_PRETYPE", @$pretype );
9493 set_list( "PERLDB_PRE", @$pre );
9494 set_list( "PERLDB_POST", @$post );
9495 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9497 # We are officially restarting.
9498 $ENV{PERLDB_RESTART} = 1;
9500 # We are junking all child debuggers.
9501 delete $ENV{PERLDB_PIDS}; # Restore ini state
9503 # Set this back to the initial pid.
9504 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9508 After all the debugger status has been saved, we take the command we built up
9509 and then return it, so we can C<exec()> it. The debugger will spot the
9510 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9511 from the environment.
9515 # And run Perl again. Add the "-d" flag, all the
9516 # flags we built up, the script (whether a one-liner
9517 # or a file), add on the -emacs flag for a slave editor,
9518 # and then the old arguments.
9520 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9526 =head1 END PROCESSING - THE C<END> BLOCK
9528 Come here at the very end of processing. We want to go into a
9529 loop where we allow the user to enter commands and interact with the
9530 debugger, but we don't want anything else to execute.
9532 First we set the C<$finished> variable, so that some commands that
9533 shouldn't be run after the end of program quit working.
9535 We then figure out whether we're truly done (as in the user entered a C<q>
9536 command, or we finished execution while running nonstop). If we aren't,
9537 we set C<$single> to 1 (causing the debugger to get control again).
9539 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9540 message and returns control to the debugger. Repeat.
9542 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9543 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9544 break, run to completion.).
9549 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9550 $fall_off_end = 1 unless $inhibit_exit;
9552 # Do not stop in at_exit() and destructors on exit:
9553 if ($fall_off_end or $runnonstop) {
9557 DB::fake::at_exit();
9561 =head1 PRE-5.8 COMMANDS
9563 Some of the commands changed function quite a bit in the 5.8 command
9564 realignment, so much so that the old code had to be replaced completely.
9565 Because we wanted to retain the option of being able to go back to the
9566 former command set, we moved the old code off to this section.
9568 There's an awful lot of duplicated code here. We've duplicated the
9569 comments to keep things clear.
9573 Does nothing. Used to I<turn off> commands.
9577 sub cmd_pre580_null {
9582 =head2 Old C<a> command.
9584 This version added actions if you supplied them, and deleted them
9593 # Argument supplied. Add the action.
9594 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9596 # If the line isn't there, use the current line.
9597 my $i = $1 || $line;
9600 # If there is an action ...
9603 # ... but the line isn't breakable, skip it.
9604 if ( $dbline[$i] == 0 ) {
9605 print $OUT "Line $i may not have an action.\n";
9609 # ... and the line is breakable:
9610 # Mark that there's an action in this file.
9611 $had_breakpoints{$filename} |= 2;
9613 # Delete any current action.
9614 $dbline{$i} =~ s/\0[^\0]*//;
9616 # Add the new action, continuing the line as needed.
9617 $dbline{$i} .= "\0" . action($j);
9619 } ## end if (length $j)
9621 # No action supplied.
9624 # Delete the action.
9625 $dbline{$i} =~ s/\0[^\0]*//;
9627 # Mark as having no break or action if nothing's left.
9628 delete $dbline{$i} if $dbline{$i} eq '';
9630 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
9631 } ## end sub cmd_pre580_a
9633 =head2 Old C<b> command
9645 if ( $cmd =~ /^load\b\s*(.*)/ ) {
9651 # b compile|postpone <some sub> [<condition>]
9652 # The interpreter actually traps this one for us; we just put the
9653 # necessary condition in the %postponed hash.
9654 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
9656 # Capture the condition if there is one. Make it true if none.
9657 my $cond = length $3 ? $3 : '1';
9659 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
9660 # if it was 'compile'.
9661 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
9663 # De-Perl4-ify the name - ' separators to ::.
9664 $subname =~ s/\'/::/g;
9666 # Qualify it into the current package unless it's already qualified.
9667 $subname = "${package}::" . $subname
9668 unless $subname =~ /::/;
9670 # Add main if it starts with ::.
9671 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
9673 # Save the break type for this sub.
9674 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
9675 } ## end elsif ($cmd =~ ...
9677 # b <sub name> [<condition>]
9678 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
9680 my $cond = length $2 ? $2 : '1';
9681 &cmd_b_sub( $subname, $cond );
9683 # b <line> [<condition>].
9684 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9685 my $i = $1 || $dbline;
9686 my $cond = length $2 ? $2 : '1';
9687 &cmd_b_line( $i, $cond );
9689 } ## end sub cmd_pre580_b
9691 =head2 Old C<D> command.
9693 Delete all breakpoints unconditionally.
9700 if ( $cmd =~ /^\s*$/ ) {
9701 print $OUT "Deleting all breakpoints...\n";
9703 # %had_breakpoints lists every file that had at least one
9706 for $file ( keys %had_breakpoints ) {
9708 # Switch to the desired file temporarily.
9709 local *dbline = $main::{ '_<' . $file };
9714 # For all lines in this file ...
9715 for my $i (1 .. $max) {
9717 # If there's a breakpoint or action on this line ...
9718 if ( defined $dbline{$i} ) {
9720 # ... remove the breakpoint.
9721 $dbline{$i} =~ s/^[^\0]+//;
9722 if ( $dbline{$i} =~ s/^\0?$// ) {
9724 # Remove the entry altogether if no action is there.
9727 } ## end if (defined $dbline{$i...
9728 } ## end for my $i (1 .. $max)
9730 # If, after we turn off the "there were breakpoints in this file"
9731 # bit, the entry in %had_breakpoints for this file is zero,
9732 # we should remove this file from the hash.
9733 if ( not $had_breakpoints{$file} &= ~1 ) {
9734 delete $had_breakpoints{$file};
9736 } ## end for $file (keys %had_breakpoints)
9738 # Kill off all the other breakpoints that are waiting for files that
9739 # haven't been loaded yet.
9741 undef %postponed_file;
9742 undef %break_on_load;
9743 } ## end if ($cmd =~ /^\s*$/)
9744 } ## end sub cmd_pre580_D
9746 =head2 Old C<h> command
9748 Print help. Defaults to printing the long-form help; the 5.8 version
9749 prints the summary by default.
9757 # Print the *right* help, long format.
9758 if ( $cmd =~ /^\s*$/ ) {
9759 print_help($pre580_help);
9762 # 'h h' - explicitly-requested summary.
9763 elsif ( $cmd =~ /^h\s*/ ) {
9764 print_help($pre580_summary);
9767 # Find and print a command's help.
9768 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
9769 my $asked = $1; # for proper errmsg
9770 my $qasked = quotemeta($asked); # for searching
9771 # XXX: finds CR but not <CR>
9775 (?:[IB]<) # Optional markup
9776 $qasked # The command name
9783 ( # The command help:
9785 (?:[IB]<) # Optional markup
9786 $qasked # The command name
9787 ([\s\S]*?) # Lines starting with tabs
9791 ) # Line not starting with space
9792 # (Next command's help)
9796 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
9800 print_help("B<$asked> is not a debugger command.\n");
9802 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
9803 } ## end sub cmd_pre580_h
9805 =head2 Old C<W> command
9807 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
9815 # Delete all watch expressions.
9816 if ( $cmd =~ /^$/ ) {
9818 # No watching is going on.
9821 # Kill all the watch expressions and values.
9822 @to_watch = @old_watch = ();
9825 # Add a watch expression.
9826 elsif ( $cmd =~ /^(.*)/s ) {
9828 # add it to the list to be watched.
9831 # Get the current value of the expression.
9832 # Doesn't handle expressions returning list values!
9834 my ($val) = DB::eval();
9835 $val = ( defined $val ) ? "'$val'" : 'undef';
9838 push @old_watch, $val;
9840 # We're watching stuff.
9843 } ## end elsif ($cmd =~ /^(.*)/s)
9844 } ## end sub cmd_pre580_W
9846 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
9848 The debugger used to have a bunch of nearly-identical code to handle
9849 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
9850 C<cmd_prepost> unify all this into one set of code to handle the
9851 appropriate actions.
9853 =head2 C<cmd_pre590_prepost>
9855 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
9856 do something destructive. In pre 5.8 debuggers, the default action was to
9857 delete all the actions.
9861 sub cmd_pre590_prepost {
9863 my $line = shift || '*';
9866 return &cmd_prepost( $cmd, $line, $dbline );
9867 } ## end sub cmd_pre590_prepost
9869 =head2 C<cmd_prepost>
9871 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
9872 Since the lists of actions are all held in arrays that are pointed to by
9873 references anyway, all we have to do is pick the right array reference and
9874 then use generic code to all, delete, or list actions.
9881 # No action supplied defaults to 'list'.
9882 my $line = shift || '?';
9884 # Figure out what to put in the prompt.
9887 # Make sure we have some array or another to address later.
9888 # This means that if ssome reason the tests fail, we won't be
9889 # trying to stash actions or delete them from the wrong place.
9892 # < - Perl code to run before prompt.
9893 if ( $cmd =~ /^\</o ) {
9894 $which = 'pre-perl';
9898 # > - Perl code to run after prompt.
9899 elsif ( $cmd =~ /^\>/o ) {
9900 $which = 'post-perl';
9904 # { - first check for properly-balanced braces.
9905 elsif ( $cmd =~ /^\{/o ) {
9906 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
9908 "$cmd is now a debugger command\nuse ';$cmd' if you mean Perl code\n";
9911 # Properly balanced. Pre-prompt debugger actions.
9913 $which = 'pre-debugger';
9916 } ## end elsif ( $cmd =~ /^\{/o )
9918 # Did we find something that makes sense?
9920 print $OUT "Confused by command: $cmd\n";
9927 if ( $line =~ /^\s*\?\s*$/o ) {
9930 # Nothing there. Complain.
9931 print $OUT "No $which actions.\n";
9935 # List the actions in the selected list.
9936 print $OUT "$which commands:\n";
9937 foreach my $action (@$aref) {
9938 print $OUT "\t$cmd -- $action\n";
9941 } ## end if ( $line =~ /^\s*\?\s*$/o)
9943 # Might be a delete.
9945 if ( length($cmd) == 1 ) {
9946 if ( $line =~ /^\s*\*\s*$/o ) {
9948 # It's a delete. Get rid of the old actions in the
9951 print $OUT "All $cmd actions cleared.\n";
9955 # Replace all the actions. (This is a <, >, or {).
9956 @$aref = action($line);
9958 } ## end if ( length($cmd) == 1)
9959 elsif ( length($cmd) == 2 ) {
9961 # Add the action to the line. (This is a <<, >>, or {{).
9962 push @$aref, action($line);
9966 # <<<, >>>>, {{{{{{ ... something not a command.
9968 "Confused by strange length of $which command($cmd)...\n";
9970 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
9972 } ## end sub cmd_prepost
9976 Contains the C<at_exit> routine that the debugger uses to issue the
9977 C<Debugged program terminated ...> message after the program completes. See
9978 the C<END> block documentation for more details.
9985 "Debugged program terminated. Use 'q' to quit or 'R' to restart.";
9988 package DB; # Do not trace this 1; below!