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
686 # Used to save @ARGV and extract any debugger-related flags.
689 # Used to prevent multiple entries to diesignal()
690 # (if for instance diesignal() itself dies)
693 # Used to prevent the debugger from running nonstop
695 use vars qw($second_time);
697 sub _calc_usercontext {
700 # Cancel strict completely for the evaluated code, so the code
701 # the user evaluates won't be affected by it. (Shlomi Fish)
702 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @DB::saved;'
703 . "package $package;"; # this won't let them modify, alas
708 # 'my' would make it visible from user code
709 # but so does local! --tchrist
710 # Remember: this localizes @DB::res, not @main::res.
714 # Try to keep the user code from messing with us. Save these so that
715 # even if the eval'ed code changes them, we can put them back again.
716 # Needed because the user could refer directly to the debugger's
717 # package globals (and any 'my' variables in this containing scope)
718 # inside the eval(), and we want to try to stay safe.
719 local $otrace = $trace;
720 local $osingle = $single;
723 # Untaint the incoming eval() argument.
724 { ($evalarg) = $evalarg =~ /(.*)/s; }
726 # $usercontext built in DB::DB near the comment
727 # "set up the context for DB::eval ..."
728 # Evaluate and save any results.
729 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
731 # Restore those old values.
737 # Save the current value of $@, and preserve it in the debugger's copy
738 # of the saved precious globals.
741 # Since we're only saving $@, we only have to localize the array element
742 # that it will be stored in.
743 local $saved[0]; # Preserve the old value of $@
746 # Now see whether we need to report an error back to the user.
752 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
753 # are package globals.
754 elsif ($onetimeDump) {
755 if ( $onetimeDump eq 'dump' ) {
756 local $option{dumpDepth} = $onetimedumpDepth
757 if defined $onetimedumpDepth;
758 dumpit( $OUT, \@res );
760 elsif ( $onetimeDump eq 'methods' ) {
763 } ## end elsif ($onetimeDump)
767 ############################################## End lexical danger zone
769 # After this point it is safe to introduce lexicals.
770 # The code being debugged will be executing in its own context, and
771 # can't see the inside of the debugger.
773 # However, one should not overdo it: leave as much control from outside as
774 # possible. If you make something a lexical, it's not going to be addressable
775 # from outside the debugger even if you know its name.
777 # This file is automatically included if you do perl -d.
778 # It's probably not useful to include this yourself.
780 # Before venturing further into these twisty passages, it is
781 # wise to read the perldebguts man page or risk the ire of dragons.
783 # (It should be noted that perldebguts will tell you a lot about
784 # the underlying mechanics of how the debugger interfaces into the
785 # Perl interpreter, but not a lot about the debugger itself. The new
786 # comments in this code try to address this problem.)
788 # Note that no subroutine call is possible until &DB::sub is defined
789 # (for subroutines defined outside of the package DB). In fact the same is
790 # true if $deep is not defined.
792 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
794 # modified Perl debugger, to be run from Emacs in perldb-mode
795 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
796 # Johan Vromans -- upgrade to 4.0 pl 10
797 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
798 ########################################################################
800 =head1 DEBUGGER INITIALIZATION
802 The debugger starts up in phases.
806 First, it initializes the environment it wants to run in: turning off
807 warnings during its own compilation, defining variables which it will need
808 to avoid warnings later, setting itself up to not exit when the program
809 terminates, and defaulting to printing return values for the C<r> command.
813 # Needed for the statement after exec():
815 # This BEGIN block is simply used to switch off warnings during debugger
816 # compilation. Probably it would be better practice to fix the warnings,
817 # but this is how it's done at the moment.
822 } # Switch compilation warnings off until another BEGIN.
824 local ($^W) = 0; # Switch run-time warnings off during init.
826 =head2 THREADS SUPPORT
828 If we are running under a threaded Perl, we require threads and threads::shared
829 if the environment variable C<PERL5DB_THREADED> is set, to enable proper
830 threaded debugger control. C<-dt> can also be used to set this.
832 Each new thread will be announced and the debugger prompt will always inform
833 you of each new thread created. It will also indicate the thread id in which
834 we are currently running within the prompt like this:
838 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
839 command prompt. The prompt will show: C<[0]> when running under threads, but
840 not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
842 While running under threads, when you set or delete a breakpoint (etc.), this
843 will apply to all threads, not just the currently running one. When you are
844 in a currently executing thread, you will stay there until it completes. With
845 the current implementation it is not currently possible to hop from one thread
848 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
850 Note that threading support was built into the debugger as of Perl version
851 C<5.8.6> and debugger version C<1.2.8>.
856 # ensure we can share our non-threaded variables or no-op
857 if ($ENV{PERL5DB_THREADED}) {
859 require threads::shared;
860 import threads::shared qw(share);
864 print "Threads support enabled\n";
871 # These variables control the execution of 'dumpvar.pl'.
886 # used to control die() reporting in diesignal()
889 use vars qw($CarpLevel);
892 # without threads, $filename is not defined until DB::DB is called
893 foreach my $k (keys (%INC)) {
894 share(\$main::{'_<'.$filename}) if defined $filename;
897 # Command-line + PERLLIB:
898 # Save the contents of @INC before they are modified elsewhere.
901 # This was an attempt to clear out the previous values of various
902 # trapped errors. Apparently it didn't help. XXX More info needed!
903 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
905 # We set these variables to safe values. We don't want to blindly turn
906 # off warnings, because other packages may still want them.
907 $trace = $signal = $single = 0; # Uninitialized warning suppression
908 # (local $^W cannot help - other packages!).
910 # Default to not exiting when program finishes; print the return
911 # value when the 'r' command is used to return from a subroutine.
912 $inhibit_exit = $option{PrintRet} = 1;
914 use vars qw($trace_to_depth);
916 # Default to 1E9 so it won't be limited to a certain recursion depth.
917 $trace_to_depth = 1E9;
919 =head1 OPTION PROCESSING
921 The debugger's options are actually spread out over the debugger itself and
922 C<dumpvar.pl>; some of these are variables to be set, while others are
923 subs to be called with a value. To try to make this a little easier to
924 manage, the debugger uses a few data structures to define what options
925 are legal and how they are to be processed.
927 First, the C<@options> array defines the I<names> of all the options that
933 CommandSet HistFile HistSize
934 hashDepth arrayDepth dumpDepth
935 DumpDBFiles DumpPackages DumpReused
936 compactDump veryCompact quote
937 HighBit undefPrint globPrint
938 PrintRet UsageOnly frame
940 ReadLine NonStop LineInfo
941 maxTraceLen recallCommand ShellBang
942 pager tkRunning ornaments
943 signalLevel warnLevel dieLevel
944 inhibit_exit ImmediateStop bareStringify
945 CreateTTY RemotePort windowSize
949 @RememberOnROptions = qw(DollarCaretP);
953 Second, C<optionVars> lists the variables that each option uses to save its
958 use vars qw(%optionVars);
961 hashDepth => \$dumpvar::hashDepth,
962 arrayDepth => \$dumpvar::arrayDepth,
963 CommandSet => \$CommandSet,
964 DumpDBFiles => \$dumpvar::dumpDBFiles,
965 DumpPackages => \$dumpvar::dumpPackages,
966 DumpReused => \$dumpvar::dumpReused,
967 HighBit => \$dumpvar::quoteHighBit,
968 undefPrint => \$dumpvar::printUndef,
969 globPrint => \$dumpvar::globPrint,
970 UsageOnly => \$dumpvar::usageOnly,
971 CreateTTY => \$CreateTTY,
972 bareStringify => \$dumpvar::bareStringify,
974 AutoTrace => \$trace,
975 inhibit_exit => \$inhibit_exit,
976 maxTraceLen => \$maxtrace,
977 ImmediateStop => \$ImmediateStop,
978 RemotePort => \$remoteport,
979 windowSize => \$window,
980 HistFile => \$histfile,
981 HistSize => \$histsize,
986 Third, C<%optionAction> defines the subroutine to be called to process each
991 use vars qw(%optionAction);
994 compactDump => \&dumpvar::compactDump,
995 veryCompact => \&dumpvar::veryCompact,
996 quote => \&dumpvar::quote,
999 ReadLine => \&ReadLine,
1000 NonStop => \&NonStop,
1001 LineInfo => \&LineInfo,
1002 recallCommand => \&recallCommand,
1003 ShellBang => \&shellBang,
1005 signalLevel => \&signalLevel,
1006 warnLevel => \&warnLevel,
1007 dieLevel => \&dieLevel,
1008 tkRunning => \&tkRunning,
1009 ornaments => \&ornaments,
1010 RemotePort => \&RemotePort,
1011 DollarCaretP => \&DollarCaretP,
1016 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1021 # Note that this list is not complete: several options not listed here
1022 # actually require that dumpvar.pl be loaded for them to work, but are
1023 # not in the table. A subsequent patch will correct this problem; for
1024 # the moment, we're just recommenting, and we are NOT going to change
1026 use vars qw(%optionRequire);
1029 compactDump => 'dumpvar.pl',
1030 veryCompact => 'dumpvar.pl',
1031 quote => 'dumpvar.pl',
1036 There are a number of initialization-related variables which can be set
1037 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1038 variable. These are:
1042 =item C<$rl> - readline control XXX needs more explanation
1044 =item C<$warnLevel> - whether or not debugger takes over warning handling
1046 =item C<$dieLevel> - whether or not debugger takes over die handling
1048 =item C<$signalLevel> - whether or not debugger takes over signal handling
1050 =item C<$pre> - preprompt actions (array reference)
1052 =item C<$post> - postprompt actions (array reference)
1056 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1058 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1064 # These guys may be defined in $ENV{PERL5DB} :
1065 $rl = 1 unless defined $rl;
1066 $warnLevel = 1 unless defined $warnLevel;
1067 $dieLevel = 1 unless defined $dieLevel;
1068 $signalLevel = 1 unless defined $signalLevel;
1069 $pre = [] unless defined $pre;
1070 $post = [] unless defined $post;
1071 $pretype = [] unless defined $pretype;
1072 $CreateTTY = 3 unless defined $CreateTTY;
1073 $CommandSet = '580' unless defined $CommandSet;
1078 share($signalLevel);
1088 The default C<die>, C<warn>, and C<signal> handlers are set up.
1092 warnLevel($warnLevel);
1093 dieLevel($dieLevel);
1094 signalLevel($signalLevel);
1098 The pager to be used is needed next. We try to get it from the
1099 environment first. If it's not defined there, we try to find it in
1100 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1101 then call the C<pager()> function to save the pager name.
1105 # This routine makes sure $pager is set up so that '|' can use it.
1108 # If PAGER is defined in the environment, use it.
1112 # If not, see if Config.pm defines it.
1113 : eval { require Config }
1114 && defined $Config::Config{pager}
1115 ? $Config::Config{pager}
1117 # If not, fall back to 'more'.
1120 unless defined $pager;
1124 We set up the command to be used to access the man pages, the command
1125 recall character (C<!> unless otherwise defined) and the shell escape
1126 character (C<!> unless otherwise defined). Yes, these do conflict, and
1127 neither works in the debugger at the moment.
1133 # Set up defaults for command recall and shell escape (note:
1134 # these currently don't work in linemode debugging).
1135 recallCommand("!") unless defined $prc;
1136 shellBang("!") unless defined $psh;
1140 We then set up the gigantic string containing the debugger help.
1141 We also set the limit on the number of arguments we'll display during a
1148 # If we didn't get a default for the length of eval/stack trace args,
1150 $maxtrace = 400 unless defined $maxtrace;
1152 =head2 SETTING UP THE DEBUGGER GREETING
1154 The debugger I<greeting> helps to inform the user how many debuggers are
1155 running, and whether the current debugger is the primary or a child.
1157 If we are the primary, we just hang onto our pid so we'll have it when
1158 or if we start a child debugger. If we are a child, we'll set things up
1159 so we'll have a unique greeting and so the parent will give us our own
1162 We save the current contents of the C<PERLDB_PIDS> environment variable
1163 because we mess around with it. We'll also need to hang onto it because
1164 we'll need it if we restart.
1166 Child debuggers make a label out of the current PID structure recorded in
1167 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1168 yet so the parent will give them one later via C<resetterm()>.
1172 # Save the current contents of the environment; we're about to
1173 # much with it. We'll need this if we have to restart.
1174 use vars qw($ini_pids);
1175 $ini_pids = $ENV{PERLDB_PIDS};
1177 use vars qw ($pids $term_pid);
1179 if ( defined $ENV{PERLDB_PIDS} ) {
1181 # We're a child. Make us a label out of the current PID structure
1182 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1183 # a term yet so the parent will give us one later via resetterm().
1185 my $env_pids = $ENV{PERLDB_PIDS};
1186 $pids = "[$env_pids]";
1188 # Unless we are on OpenVMS, all programs under the DCL shell run under
1191 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1195 $ENV{PERLDB_PIDS} .= "->$$";
1199 } ## end if (defined $ENV{PERLDB_PIDS...
1202 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1203 # child debugger, and mark us as the parent, so we'll know to set up
1204 # more TTY's is we have to.
1205 $ENV{PERLDB_PIDS} = "$$";
1210 use vars qw($pidprompt);
1213 # Sets up $emacs as a synonym for $slave_editor.
1214 use vars qw($slave_editor);
1215 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1217 =head2 READING THE RC FILE
1219 The debugger will read a file of initialization options if supplied. If
1220 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1224 # As noted, this test really doesn't check accurately that the debugger
1225 # is running at a terminal or not.
1227 use vars qw($rcfile);
1229 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1230 # this is the wrong metric!
1231 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
1236 The debugger does a safety test of the file to be read. It must be owned
1237 either by the current user or root, and must only be writable by the owner.
1241 # This wraps a safety test around "do" to read and evaluate the init file.
1243 # This isn't really safe, because there's a race
1244 # between checking and opening. The solution is to
1245 # open and fstat the handle, but then you have to read and
1246 # eval the contents. But then the silly thing gets
1247 # your lexical scope, which is unfortunate at best.
1251 # Just exactly what part of the word "CORE::" don't you understand?
1252 local $SIG{__WARN__};
1253 local $SIG{__DIE__};
1255 unless ( is_safe_file($file) ) {
1256 CORE::warn <<EO_GRIPE;
1257 perldb: Must not source insecure rcfile $file.
1258 You or the superuser must be the owner, and it must not
1259 be writable by anyone but its owner.
1262 } ## end unless (is_safe_file($file...
1265 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1266 } ## end sub safe_do
1268 # This is the safety test itself.
1270 # Verifies that owner is either real user or superuser and that no
1271 # one but owner may write to it. This function is of limited use
1272 # when called on a path instead of upon a handle, because there are
1273 # no guarantees that filename (by dirent) whose file (by ino) is
1274 # eventually accessed is the same as the one tested.
1275 # Assumes that the file's existence is not in doubt.
1278 stat($path) || return; # mysteriously vaporized
1279 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1281 return 0 if $uid != 0 && $uid != $<;
1282 return 0 if $mode & 022;
1284 } ## end sub is_safe_file
1286 # If the rcfile (whichever one we decided was the right one to read)
1287 # exists, we safely do it.
1289 safe_do("./$rcfile");
1292 # If there isn't one here, try the user's home directory.
1293 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1294 safe_do("$ENV{HOME}/$rcfile");
1297 # Else try the login directory.
1298 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1299 safe_do("$ENV{LOGDIR}/$rcfile");
1302 # If the PERLDB_OPTS variable has options in it, parse those out next.
1303 if ( defined $ENV{PERLDB_OPTS} ) {
1304 parse_options( $ENV{PERLDB_OPTS} );
1309 The last thing we do during initialization is determine which subroutine is
1310 to be used to obtain a new terminal when a new debugger is started. Right now,
1311 the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
1316 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1317 # Works if you're running an xterm or xterm-like window, or you're on
1318 # OS/2, or on Mac OS X. This may need some expansion.
1320 if (not defined &get_fork_TTY) # only if no routine exists
1322 if ( defined $remoteport ) {
1323 # Expect an inetd-like server
1324 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1326 elsif (defined $ENV{TERM} # If we know what kind
1327 # of terminal this is,
1328 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1329 and defined $ENV{DISPLAY} # and what display it's on,
1332 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1334 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1335 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1337 elsif ( $^O eq 'darwin' # If this is Mac OS X
1338 and defined $ENV{TERM_PROGRAM} # and we're running inside
1339 and $ENV{TERM_PROGRAM}
1340 eq 'Apple_Terminal' # Terminal.app
1343 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1345 } ## end if (not defined &get_fork_TTY...
1347 # untaint $^O, which may have been tainted by the last statement.
1348 # see bug [perl #24674]
1352 # Here begin the unreadable code. It needs fixing.
1354 =head2 RESTART PROCESSING
1356 This section handles the restart command. When the C<R> command is invoked, it
1357 tries to capture all of the state it can into environment variables, and
1358 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1359 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1360 the R command stuffed into the environment variables.
1362 PERLDB_RESTART - flag only, contains no restart data itself.
1363 PERLDB_HIST - command history, if it's available
1364 PERLDB_ON_LOAD - breakpoints set by the rc file
1365 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1366 PERLDB_VISITED - files that had breakpoints
1367 PERLDB_FILE_... - breakpoints for a file
1368 PERLDB_OPT - active options
1369 PERLDB_INC - the original @INC
1370 PERLDB_PRETYPE - preprompt debugger actions
1371 PERLDB_PRE - preprompt Perl code
1372 PERLDB_POST - post-prompt Perl code
1373 PERLDB_TYPEAHEAD - typeahead captured by readline()
1375 We chug through all these variables and plug the values saved in them
1376 back into the appropriate spots in the debugger.
1380 use vars qw(@hist @truehist %postponed_file @typeahead);
1382 sub _restore_shared_globals_after_restart
1384 @hist = get_list('PERLDB_HIST');
1385 %break_on_load = get_list("PERLDB_ON_LOAD");
1386 %postponed = get_list("PERLDB_POSTPONE");
1390 share(%break_on_load);
1394 sub _restore_breakpoints_and_actions {
1396 my @had_breakpoints = get_list("PERLDB_VISITED");
1398 for my $file_idx ( 0 .. $#had_breakpoints ) {
1399 my $filename = $had_breakpoints[$file_idx];
1400 my %pf = get_list("PERLDB_FILE_$file_idx");
1401 $postponed_file{ $filename } = \%pf if %pf;
1402 my @lines = sort {$a <=> $b} keys(%pf);
1403 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1404 for my $line_idx (0 .. $#lines) {
1405 _set_breakpoint_enabled_status(
1408 ($enabled_statuses[$line_idx] ? 1 : ''),
1416 sub _restore_options_after_restart
1418 my %options_map = get_list("PERLDB_OPT");
1420 while ( my ( $opt, $val ) = each %options_map ) {
1421 $val =~ s/[\\\']/\\$1/g;
1422 parse_options("$opt'$val'");
1428 sub _restore_globals_after_restart
1430 # restore original @INC
1431 @INC = get_list("PERLDB_INC");
1434 # return pre/postprompt actions and typeahead buffer
1435 $pretype = [ get_list("PERLDB_PRETYPE") ];
1436 $pre = [ get_list("PERLDB_PRE") ];
1437 $post = [ get_list("PERLDB_POST") ];
1438 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1444 if ( exists $ENV{PERLDB_RESTART} ) {
1446 # We're restarting, so we don't need the flag that says to restart anymore.
1447 delete $ENV{PERLDB_RESTART};
1450 _restore_shared_globals_after_restart();
1452 _restore_breakpoints_and_actions();
1455 _restore_options_after_restart();
1457 _restore_globals_after_restart();
1458 } ## end if (exists $ENV{PERLDB_RESTART...
1460 =head2 SETTING UP THE TERMINAL
1462 Now, we'll decide how the debugger is going to interact with the user.
1463 If there's no TTY, we set the debugger to run non-stop; there's not going
1464 to be anyone there to enter commands.
1468 use vars qw($notty $runnonstop $console $tty $LINEINFO);
1469 use vars qw($lineinfo $doccmd);
1478 If there is a TTY, we have to determine who it belongs to before we can
1479 proceed. If this is a slave editor or graphical debugger (denoted by
1480 the first command-line switch being '-emacs'), we shift this off and
1481 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1487 # Is Perl being run from a slave editor or graphical debugger?
1488 # If so, don't use readline, and set $slave_editor = 1.
1489 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1494 #require Term::ReadLine;
1498 We then determine what the console should be on various systems:
1502 =item * Cygwin - We use C<stdin> instead of a separate device.
1506 if ( $^O eq 'cygwin' ) {
1508 # /dev/tty is binary. use stdin for textmode
1512 =item * Unix - use C</dev/tty>.
1516 elsif ( -e "/dev/tty" ) {
1517 $console = "/dev/tty";
1520 =item * Windows or MSDOS - use C<con>.
1524 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1528 =item * VMS - use C<sys$command>.
1534 # everything else is ...
1535 $console = "sys\$command";
1542 Several other systems don't use a specific console. We C<undef $console>
1543 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1544 with a slave editor, Epoc).
1548 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1550 # /dev/tty is binary. use stdin for textmode
1554 if ( $^O eq 'NetWare' ) {
1556 # /dev/tty is binary. use stdin for textmode
1560 # In OS/2, we need to use STDIN to get textmode too, even though
1561 # it pretty much looks like Unix otherwise.
1562 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1567 # EPOC also falls into the 'got to use STDIN' camp.
1568 if ( $^O eq 'epoc' ) {
1574 If there is a TTY hanging around from a parent, we use that as the console.
1578 $console = $tty if defined $tty;
1580 =head2 SOCKET HANDLING
1582 The debugger is capable of opening a socket and carrying out a debugging
1583 session over the socket.
1585 If C<RemotePort> was defined in the options, the debugger assumes that it
1586 should try to start a debugging session on that port. It builds the socket
1587 and then tries to connect the input and output filehandles to it.
1591 # Handle socket stuff.
1593 if ( defined $remoteport ) {
1595 # If RemotePort was defined in the options, connect input and output
1597 $IN = $OUT = connect_remoteport();
1598 } ## end if (defined $remoteport)
1602 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1603 this is probably a situation where multiple debuggers are running (for example,
1604 a backticked command that starts up another debugger). We create a new IN and
1605 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1613 # Two debuggers running (probably a system or a backtick that invokes
1614 # the debugger itself under the running one). create a new IN and OUT
1615 # filehandle, and do the necessary mojo to create a new tty if we
1616 # know how, and we can.
1617 create_IN_OUT(4) if $CreateTTY & 4;
1620 # If we have a console, check to see if there are separate ins and
1621 # outs to open. (They are assumed identical if not.)
1623 my ( $i, $o ) = split /,/, $console;
1624 $o = $i unless defined $o;
1626 # read/write on in, or just read, or read on STDIN.
1628 || open( IN, "<$i" )
1629 || open( IN, "<&STDIN" );
1631 # read/write/create/clobber out, or write/create/clobber out,
1632 # or merge with STDERR, or merge with STDOUT.
1634 || open( OUT, ">$o" )
1635 || open( OUT, ">&STDERR" )
1636 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1638 } ## end if ($console)
1639 elsif ( not defined $console ) {
1641 # No console. Open STDIN.
1642 open( IN, "<&STDIN" );
1644 # merge with STDERR, or with STDOUT.
1645 open( OUT, ">&STDERR" )
1646 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1647 $console = 'STDIN/OUT';
1648 } ## end elsif (not defined $console)
1650 # Keep copies of the filehandles so that when the pager runs, it
1651 # can close standard input without clobbering ours.
1652 if ($console or (not defined($console))) {
1656 } ## end elsif (from if(defined $remoteport))
1658 # Unbuffer DB::OUT. We need to see responses right away.
1661 # Line info goes to debugger output unless pointed elsewhere.
1662 # Pointing elsewhere makes it possible for slave editors to
1663 # keep track of file and position. We have both a filehandle
1664 # and a I/O description to keep track of.
1665 $LINEINFO = $OUT unless defined $LINEINFO;
1666 $lineinfo = $console unless defined $lineinfo;
1667 # share($LINEINFO); # <- unable to share globs
1672 To finish initialization, we show the debugger greeting,
1673 and then call the C<afterinit()> subroutine if there is one.
1677 # Show the debugger greeting.
1678 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1679 unless ($runnonstop) {
1682 if ( $term_pid eq '-1' ) {
1683 print $OUT "\nDaughter DB session started...\n";
1686 print $OUT "\nLoading DB routines from $header\n";
1689 $slave_editor ? "enabled" : "available", ".\n"
1692 "\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
1693 } ## end else [ if ($term_pid eq '-1')
1694 } ## end unless ($runnonstop)
1695 } ## end else [ if ($notty)
1697 # XXX This looks like a bug to me.
1698 # Why copy to @ARGS and then futz with @args?
1701 # Make sure backslashes before single quotes are stripped out, and
1702 # keep args unless they are numeric (XXX why?)
1703 # s/\'/\\\'/g; # removed while not justified understandably
1704 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1707 # If there was an afterinit() sub defined, call it. It will get
1708 # executed in our scope, so it can fiddle with debugger globals.
1709 if ( defined &afterinit ) { # May be defined in $rcfile
1713 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1714 use vars qw($I_m_init);
1718 ############################################################ Subroutines
1724 This gigantic subroutine is the heart of the debugger. Called before every
1725 statement, its job is to determine if a breakpoint has been reached, and
1726 stop if so; read commands from the user, parse them, and execute
1727 them, and then send execution off to the next statement.
1729 Note that the order in which the commands are processed is very important;
1730 some commands earlier in the loop will actually alter the C<$cmd> variable
1731 to create other commands to be executed later. This is all highly I<optimized>
1732 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1733 see what's happening in any given command.
1762 sub _DB__determine_if_we_should_break
1764 # if we have something here, see if we should break.
1765 # $stop is lexical and local to this block - $action on the other hand
1770 && _is_breakpoint_enabled($filename, $line)
1771 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1774 # Stop if the stop criterion says to just stop.
1775 if ( $stop eq '1' ) {
1779 # It's a conditional stop; eval it in the user's context and
1780 # see if we should stop. If so, remove the one-time sigil.
1782 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1784 # If the breakpoint is temporary, then delete its enabled status.
1785 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1786 _cancel_breakpoint_temp_enabled_status($filename, $line);
1789 } ## end if ($dbline{$line} && ...
1792 sub _DB__is_finished {
1793 if ($finished and $level <= 1) {
1802 sub _DB__read_next_cmd
1806 # We have a terminal, or can get one ...
1811 # ... and it belogs to this PID or we get one for this PID ...
1812 if ($term_pid != $$) {
1816 # ... and we got a line of command input ...
1817 $cmd = DB::readline(
1818 "$pidprompt $tid DB"
1821 . ( '>' x $level ) . " "
1824 return defined($cmd);
1827 sub _DB__trim_command_and_return_first_component {
1828 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1829 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1837 # lock the debugger and get the thread id for the prompt
1841 my ($prefix, $after, $infix);
1845 if ($ENV{PERL5DB_THREADED}) {
1846 $tid = eval { "[".threads->tid."]" };
1849 my $obj = DB::Obj->new(
1851 position => \$position,
1854 explicit_stop => \$explicit_stop,
1859 $obj->_DB_on_init__initialize_globals(@_);
1861 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1862 # The code being debugged may have altered them.
1865 # Since DB::DB gets called after every line, we can use caller() to
1866 # figure out where we last were executing. Sneaky, eh? This works because
1867 # caller is returning all the extra information when called from the
1869 local ( $package, $filename, $line ) = caller;
1870 $filename_ini = $filename;
1872 # set up the context for DB::eval, so it can properly execute
1873 # code on behalf of the user. We add the package in so that the
1874 # code is eval'ed in the proper package (not in the debugger!).
1875 local $usercontext = _calc_usercontext($package);
1877 # Create an alias to the active file magical array to simplify
1879 local (*dbline) = $main::{ '_<' . $filename };
1881 # Last line in the program.
1884 _DB__determine_if_we_should_break(@_);
1886 # Preserve the current stop-or-not, and see if any of the W
1887 # (watch expressions) has changed.
1888 my $was_signal = $signal;
1890 # If we have any watch expressions ...
1891 $obj->_DB__handle_watch_expressions(@_);
1893 =head2 C<watchfunction()>
1895 C<watchfunction()> is a function that can be defined by the user; it is a
1896 function which will be run on each entry to C<DB::DB>; it gets the
1897 current package, filename, and line as its parameters.
1899 The watchfunction can do anything it likes; it is executing in the
1900 debugger's context, so it has access to all of the debugger's internal
1901 data structures and functions.
1903 C<watchfunction()> can control the debugger's actions. Any of the following
1904 will cause the debugger to return control to the user's program after
1905 C<watchfunction()> executes:
1911 Returning a false value from the C<watchfunction()> itself.
1915 Altering C<$single> to a false value.
1919 Altering C<$signal> to a false value.
1923 Turning off the C<4> bit in C<$trace> (this also disables the
1924 check for C<watchfunction()>. This can be done with
1932 # If there's a user-defined DB::watchfunction, call it with the
1933 # current package, filename, and line. The function executes in
1935 if ( $trace & 4 ) { # User-installed watch
1937 if watchfunction( $package, $filename, $line )
1940 and not( $trace & ~4 );
1941 } ## end if ($trace & 4)
1943 # Pick up any alteration to $signal in the watchfunction, and
1944 # turn off the signal now.
1945 $was_signal = $signal;
1948 =head2 GETTING READY TO EXECUTE COMMANDS
1950 The debugger decides to take control if single-step mode is on, the
1951 C<t> command was entered, or the user generated a signal. If the program
1952 has fallen off the end, we set things up so that entering further commands
1953 won't cause trouble, and we say that the program is over.
1957 # Make sure that we always print if asked for explicitly regardless
1958 # of $trace_to_depth .
1959 $explicit_stop = ($single || $was_signal);
1961 # Check to see if we should grab control ($single true,
1962 # trace set appropriately, or we got a signal).
1963 if ( $explicit_stop || ( $trace & 1 ) ) {
1964 $obj->_DB__grab_control(@_);
1965 } ## end if ($single || ($trace...
1969 If there's an action to be executed for the line we stopped at, execute it.
1970 If there are any preprompt actions, execute those as well.
1974 # If there's an action, do it now.
1980 # Are we nested another level (e.g., did we evaluate a function
1981 # that had a breakpoint in it at the debugger prompt)?
1982 if ( $single || $was_signal ) {
1984 # Yes, go down a level.
1985 local $level = $level + 1;
1987 # Do any pre-prompt actions.
1988 foreach $evalarg (@$pre) {
1992 # Complain about too much recursion if we passed the limit.
1994 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
1997 # The line we're currently on. Set $incr to -1 to stay here
1998 # until we get a command that tells us to advance.
2000 $incr = -1; # for backward motion.
2002 # Tack preprompt debugger actions ahead of any actual input.
2003 @typeahead = ( @$pretype, @typeahead );
2005 =head2 WHERE ARE WE?
2007 XXX Relocate this section?
2009 The debugger normally shows the line corresponding to the current line of
2010 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2011 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2013 C<$incr> controls by how many lines the I<current> line should move forward
2014 after a command is executed. If set to -1, this indicates that the I<current>
2015 line shouldn't change.
2017 C<$start> is the I<current> line. It is used for things like knowing where to
2018 move forwards or backwards from when doing an C<L> or C<-> command.
2020 C<$max> tells the debugger where the last line of the current file is. It's
2021 used to terminate loops most often.
2023 =head2 THE COMMAND LOOP
2025 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2032 The outer part of the loop, starting at the C<CMD> label. This loop
2033 reads a command and then executes it.
2037 The inner part of the loop, starting at the C<PIPE> label. This part
2038 is wholly contained inside the C<CMD> block and only executes a command.
2039 Used to handle commands running inside a pager.
2043 So why have two labels to restart the loop? Because sometimes, it's easier to
2044 have a command I<generate> another command and then re-execute the loop to do
2045 the new command. This is faster, but perhaps a bit more convoluted.
2049 # The big command dispatch loop. It keeps running until the
2050 # user yields up control again.
2052 # If we have a terminal for input, and we get something back
2053 # from readline(), keep on processing.
2058 while (_DB__read_next_cmd($tid))
2062 # ... try to execute the input as debugger commands.
2064 # Don't stop running.
2067 # No signal is active.
2070 # Handle continued commands (ending with \):
2071 if ($cmd =~ s/\\\z/\n/) {
2072 $cmd .= DB::readline(" cont: ");
2076 =head4 The null command
2078 A newline entered by itself means I<re-execute the last command>. We grab the
2079 command out of C<$laststep> (where it was recorded previously), and copy it
2080 back into C<$cmd> to be executed below. If there wasn't any previous command,
2081 we'll do nothing below (no command will match). If there was, we also save it
2082 in the command history and fall through to allow the command parsing to pick
2087 # Empty input means repeat the last command.
2091 chomp($cmd); # get rid of the annoying extra newline
2092 if (length($cmd) >= 2) {
2093 push( @hist, $cmd );
2095 push( @truehist, $cmd );
2099 # This is a restart point for commands that didn't arrive
2100 # via direct user input. It allows us to 'redo PIPE' to
2101 # re-execute command processing without reading a new command.
2103 my $i = _DB__trim_command_and_return_first_component();
2105 =head3 COMMAND ALIASES
2107 The debugger can create aliases for commands (these are stored in the
2108 C<%alias> hash). Before a command is executed, the command loop looks it up
2109 in the alias hash and substitutes the contents of the alias for the command,
2110 completely replacing it.
2114 # See if there's an alias for the command, and set it up if so.
2117 # Squelch signal handling; we want to keep control here
2118 # if something goes loco during the alias eval.
2119 local $SIG{__DIE__};
2120 local $SIG{__WARN__};
2122 # This is a command, so we eval it in the DEBUGGER's
2123 # scope! Otherwise, we can't see the special debugger
2124 # variables, or get to the debugger's subs. (Well, we
2125 # _could_, but why make it even more complicated?)
2126 eval "\$cmd =~ $alias{$i}";
2129 print $OUT "Couldn't evaluate '$i' alias: $@";
2132 } ## end if ($alias{$i})
2134 =head3 MAIN-LINE COMMANDS
2136 All of these commands work up to and after the program being debugged has
2141 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2142 try to execute further, cleaning any restart-related stuff out of the
2143 environment, and executing with the last value of C<$?>.
2153 =head4 C<t> - trace [n]
2155 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2156 If level is specified, set C<$trace_to_depth>.
2160 $obj->_handle_t_command();
2162 =head4 C<S> - list subroutines matching/not matching a pattern
2164 Walks through C<%sub>, checking to see whether or not to print the name.
2168 if (my ($print_all_subs, $should_reverse, $Spatt)
2169 = $cmd =~ /\AS(\s+(!)?(.+))?\z/) {
2170 # $Spatt is the pattern (if any) to use.
2172 my $Srev = defined $should_reverse;
2173 # No args - print all subs.
2174 my $Snocheck = !defined $print_all_subs;
2176 # Need to make these sane here.
2180 # Search through the debugger's magical hash of subs.
2181 # If $nocheck is true, just print the sub name.
2182 # Otherwise, check it against the pattern. We then use
2183 # the XOR trick to reverse the condition as required.
2184 foreach $subname ( sort( keys %sub ) ) {
2185 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2186 print $OUT $subname, "\n";
2192 =head4 C<X> - list variables in current package
2194 Since the C<V> command actually processes this, just change this to the
2195 appropriate C<V> command and fall through.
2199 $cmd =~ s/^X\b/V $package/;
2201 =head4 C<V> - list variables
2203 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2207 # Bare V commands get the currently-being-debugged package
2210 $cmd = "V $package";
2213 # V - show variables in package.
2214 if (my ($new_packname, $new_vars_str) =
2215 $cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
2217 # Save the currently selected filehandle and
2218 # force output to debugger's filehandle (dumpvar
2219 # just does "print" for output).
2220 my $savout = select($OUT);
2222 # Grab package name and variables to dump.
2223 $packname = $new_packname;
2224 my @vars = split( ' ', $new_vars_str );
2226 # If main::dumpvar isn't here, get it.
2227 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
2228 if ( defined &main::dumpvar ) {
2230 # We got it. Turn off subroutine entry/exit messages
2231 # for the moment, along with return values.
2235 # must detect sigpipe failures - not catching
2236 # then will cause the debugger to die.
2240 defined $option{dumpDepth}
2241 ? $option{dumpDepth}
2242 : -1, # assume -1 unless specified
2247 # The die doesn't need to include the $@, because
2248 # it will automatically get propagated for us.
2250 die unless $@ =~ /dumpvar print failed/;
2252 } ## end if (defined &main::dumpvar)
2255 # Couldn't load dumpvar.
2256 print $OUT "dumpvar.pl not available.\n";
2259 # Restore the output filehandle, and go round again.
2264 =head4 C<x> - evaluate and print an expression
2266 Hands the expression off to C<DB::eval>, setting it up to print the value
2267 via C<dumpvar.pl> instead of just printing it directly.
2271 if ($cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
2272 $onetimeDump = 'dump'; # main::dumpvar shows the output
2274 # handle special "x 3 blah" syntax XXX propagate
2275 # doc back to special variables.
2276 if ( $cmd =~ s#\A\s*(\d+)(?=\s)# #) {
2277 $onetimedumpDepth = $1;
2281 =head4 C<m> - print methods
2283 Just uses C<DB::methods> to determine what methods are available.
2287 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2292 # m expr - set up DB::eval to do the work
2293 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2294 $onetimeDump = 'methods'; # method output gets used there
2297 =head4 C<f> - switch files
2301 if (($file) = $cmd =~ /\Af\b\s*(.*)/) {
2304 # help for no arguments (old-style was return from sub).
2307 "The old f command is now the r command.\n"; # hint
2308 print $OUT "The new f command switches filenames.\n";
2310 } ## end if (!$file)
2312 # if not in magic file list, try a close match.
2313 if ( !defined $main::{ '_<' . $file } ) {
2314 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2316 $try = substr( $try, 2 );
2317 print $OUT "Choosing $try matching '$file':\n";
2320 } ## end if (($try) = grep(m#^_<.*$file#...
2321 } ## end if (!defined $main::{ ...
2323 # If not successfully switched now, we failed.
2324 if ( !defined $main::{ '_<' . $file } ) {
2325 print $OUT "No file matching '$file' is loaded.\n";
2329 # We switched, so switch the debugger internals around.
2330 elsif ( $file ne $filename ) {
2331 *dbline = $main::{ '_<' . $file };
2336 } ## end elsif ($file ne $filename)
2338 # We didn't switch; say we didn't.
2340 print $OUT "Already in $file.\n";
2345 =head4 C<.> - return to last-executed line.
2347 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2348 and then we look up the line in the magical C<%dbline> hash.
2354 $incr = -1; # stay at current line
2356 # Reset everything to the old location.
2358 $filename = $filename_ini;
2359 *dbline = $main::{ '_<' . $filename };
2363 print_lineinfo($position);
2367 =head4 C<-> - back one window
2369 We change C<$start> to be one window back; if we go back past the first line,
2370 we set it to be the first line. We ser C<$incr> to put us back at the
2371 currently-executing line, and then put a C<l $start +> (list one window from
2372 C<$start>) in C<$cmd> to be executed later.
2376 # - - back a window.
2379 # back up by a window; go to 1 if back too far.
2380 $start -= $incr + $window + 1;
2381 $start = 1 if $start <= 0;
2382 $incr = $window - 1;
2384 # Generate and execute a "l +" command (handled below).
2385 $cmd = 'l ' . ($start) . '+';
2388 =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>>
2390 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2391 problems, most notably that the default case of several commands destroying
2392 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2393 retain the old commands for those who were used to using them or who preferred
2394 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2395 deal with them instead of processing them in-line.
2399 # All of these commands were remapped in perl 5.8.0;
2400 # we send them off to the secondary dispatcher (see below).
2401 if (my ($cmd_letter, $my_arg) = $cmd =~ /\A([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so) {
2402 &cmd_wrapper( $cmd_letter, $my_arg, $line );
2406 =head4 C<y> - List lexicals in higher scope
2408 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2409 above the current one and then displays then using C<dumpvar.pl>.
2413 if (my ($match_level, $match_vars)
2414 = $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/) {
2416 # See if we've got the necessary support.
2417 eval { require PadWalker; PadWalker->VERSION(0.08) }
2420 ? "PadWalker module not found - please install\n"
2425 # Load up dumpvar if we don't have it. If we can, that is.
2426 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
2427 defined &main::dumpvar
2428 or print $OUT "dumpvar.pl not available.\n"
2431 # Got all the modules we need. Find them and print them.
2432 my @vars = split( ' ', $match_vars || '' );
2435 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 1 ) };
2437 # Oops. Can't find it.
2438 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2440 # Show the desired vars with dumplex().
2441 my $savout = select($OUT);
2443 # Have dumplex dump the lexicals.
2444 dumpvar::dumplex( $_, $h->{$_},
2445 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
2452 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2454 All of the commands below this point don't work after the program being
2455 debugged has ended. All of them check to see if the program has ended; this
2456 allows the commands to be relocated without worrying about a 'line of
2457 demarcation' above which commands can be entered anytime, and below which
2460 =head4 C<n> - single step, but don't trace down into subs
2462 Done by setting C<$single> to 2, which forces subs to execute straight through
2463 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2464 so a null command knows what to re-execute.
2470 next CMD if _DB__is_finished();
2472 # Single step, but don't enter subs.
2475 # Save for empty command (repeat last).
2480 =head4 C<s> - single-step, entering subs
2482 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2483 subs. Also saves C<s> as C<$lastcmd>.
2490 # Get out and restart the command loop if program
2492 next CMD if _DB__is_finished();
2494 # Single step should enter subs.
2497 # Save for empty command (repeat last).
2502 =head4 C<c> - run continuously, setting an optional breakpoint
2504 Most of the code for this command is taken up with locating the optional
2505 breakpoint, which is either a subroutine name or a line number. We set
2506 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2507 in this and all call levels above this one.
2511 # c - start continuous execution.
2512 if (($i) = $cmd =~ m#\Ac\b\s*([\w:]*)\s*\z#) {
2514 # Hey, show's over. The debugged program finished
2515 # executing already.
2516 next CMD if _DB__is_finished();
2518 # Capture the place to put a one-time break.
2521 # Probably not needed, since we finish an interactive
2522 # sub-session anyway...
2523 # local $filename = $filename;
2524 # local *dbline = *dbline; # XXX Would this work?!
2526 # The above question wonders if localizing the alias
2527 # to the magic array works or not. Since it's commented
2528 # out, we'll just leave that to speculation for now.
2530 # If the "subname" isn't all digits, we'll assume it
2531 # is a subroutine name, and try to find it.
2532 if ( $subname =~ /\D/ ) { # subroutine name
2533 # Qualify it to the current package unless it's
2534 # already qualified.
2535 $subname = $package . "::" . $subname
2536 unless $subname =~ /::/;
2538 # find_sub will return "file:line_number" corresponding
2539 # to where the subroutine is defined; we call find_sub,
2540 # break up the return value, and assign it in one
2542 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2544 # Force the line number to be numeric.
2547 # If we got a line number, we found the sub.
2550 # Switch all the debugger's internals around so
2551 # we're actually working with that file.
2553 *dbline = $main::{ '_<' . $filename };
2555 # Mark that there's a breakpoint in this file.
2556 $had_breakpoints{$filename} |= 1;
2558 # Scan forward to the first executable line
2559 # after the 'sub whatever' line.
2561 ++$i while $dbline[$i] == 0 && $i < $max;
2564 # We didn't find a sub by that name.
2566 print $OUT "Subroutine $subname not found.\n";
2569 } ## end if ($subname =~ /\D/)
2571 # At this point, either the subname was all digits (an
2572 # absolute line-break request) or we've scanned through
2573 # the code following the definition of the sub, looking
2574 # for an executable, which we may or may not have found.
2576 # If $i (which we set $subname from) is non-zero, we
2577 # got a request to break at some line somewhere. On
2578 # one hand, if there wasn't any real subroutine name
2579 # involved, this will be a request to break in the current
2580 # file at the specified line, so we have to check to make
2581 # sure that the line specified really is breakable.
2583 # On the other hand, if there was a subname supplied, the
2584 # preceding block has moved us to the proper file and
2585 # location within that file, and then scanned forward
2586 # looking for the next executable line. We have to make
2587 # sure that one was found.
2589 # On the gripping hand, we can't do anything unless the
2590 # current value of $i points to a valid breakable line.
2595 if ( $dbline[$i] == 0 ) {
2596 print $OUT "Line $i not breakable.\n";
2600 # Yes. Set up the one-time-break sigil.
2601 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2602 _enable_breakpoint_temp_enabled_status($filename, $i);
2605 # Turn off stack tracing from here up.
2606 for my $i (0 .. $stack_depth) {
2612 =head4 C<r> - return from a subroutine
2614 For C<r> to work properly, the debugger has to stop execution again
2615 immediately after the return is executed. This is done by forcing
2616 single-stepping to be on in the call level above the current one. If
2617 we are printing return values when a C<r> is executed, set C<$doret>
2618 appropriately, and force us out of the command loop.
2622 # r - return from the current subroutine.
2625 # Can't do anything if the program's over.
2626 next CMD if _DB__is_finished();
2628 # Turn on stack trace.
2629 $stack[$stack_depth] |= 1;
2631 # Print return value unless the stack is empty.
2632 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2636 =head4 C<T> - stack trace
2638 Just calls C<DB::print_trace>.
2643 print_trace( $OUT, 1 ); # skip DB
2647 =head4 C<w> - List window around current line.
2649 Just calls C<DB::cmd_w>.
2653 if (my ($arg) = $cmd =~ /\Aw\b\s*(.*)/s) {
2654 &cmd_w( 'w', $arg );
2658 =head4 C<W> - watch-expression processing.
2660 Just calls C<DB::cmd_W>.
2664 if (my ($arg) = $cmd =~ /\AW\b\s*(.*)/s) {
2665 &cmd_W( 'W', $arg );
2669 =head4 C</> - search forward for a string in the source
2671 We take the argument and treat it as a pattern. If it turns out to be a
2672 bad one, we return the error we got from trying to C<eval> it and exit.
2673 If not, we create some code to do the search and C<eval> it so it can't
2678 # The pattern as a string.
2679 use vars qw($inpat);
2681 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2683 # Remove the final slash.
2684 $inpat =~ s:([^\\])/$:$1:;
2686 # If the pattern isn't null ...
2687 if ( $inpat ne "" ) {
2689 # Turn of warn and die procesing for a bit.
2690 local $SIG{__DIE__};
2691 local $SIG{__WARN__};
2693 # Create the pattern.
2694 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2697 # Oops. Bad pattern. No biscuit.
2698 # Print the eval error and go back for more
2704 } ## end if ($inpat ne "")
2706 # Set up to stop on wrap-around.
2709 # Don't move off the current line.
2712 # Done in eval so nothing breaks if the pattern
2713 # does something weird.
2717 # Move ahead one line.
2720 # Wrap if we pass the last line.
2721 $start = 1 if ($start > $max);
2723 # Stop if we have gotten back to this line again,
2724 last if ($start == $end);
2726 # A hit! (Note, though, that we are doing
2727 # case-insensitive matching. Maybe a qr//
2728 # expression would be better, so the user could
2729 # do case-sensitive matching if desired.
2730 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2731 if ($slave_editor) {
2732 # Handle proper escaping in the slave.
2733 print $OUT "\032\032$filename:$start:0\n";
2736 # Just print the line normally.
2737 print $OUT "$start:\t",$dbline[$start],"\n";
2739 # And quit since we found something.
2744 # If we wrapped, there never was a match.
2745 print $OUT "/$pat/: not found\n" if ( $start == $end );
2749 =head4 C<?> - search backward for a string in the source
2751 Same as for C</>, except the loop runs backwards.
2755 # ? - backward pattern search.
2756 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2758 # Get the pattern, remove trailing question mark.
2759 $inpat =~ s:([^\\])\?$:$1:;
2761 # If we've got one ...
2762 if ( $inpat ne "" ) {
2764 # Turn off die & warn handlers.
2765 local $SIG{__DIE__};
2766 local $SIG{__WARN__};
2767 eval '$inpat =~ m' . "\a$inpat\a";
2771 # Ouch. Not good. Print the error.
2776 } ## end if ($inpat ne "")
2778 # Where we are now is where to stop after wraparound.
2781 # Don't move away from this line.
2784 # Search inside the eval to prevent pattern badness
2792 # Wrap if we pass the first line.
2794 $start = $max if ($start <= 0);
2796 # Quit if we get back where we started,
2797 last if ($start == $end);
2800 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2801 if ($slave_editor) {
2802 # Yep, follow slave editor requirements.
2803 print $OUT "\032\032$filename:$start:0\n";
2806 # Yep, just print normally.
2807 print $OUT "$start:\t",$dbline[$start],"\n";
2815 # Say we failed if the loop never found anything,
2816 print $OUT "?$pat?: not found\n" if ( $start == $end );
2820 =head4 C<$rc> - Recall command
2822 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2823 that the terminal supports history). It find the the command required, puts it
2824 into C<$cmd>, and redoes the loop to execute it.
2828 # $rc - recall command.
2829 if (my ($minus, $arg) = $cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
2831 # No arguments, take one thing off history.
2832 pop(@hist) if length($cmd) > 1;
2834 # Relative (- found)?
2835 # Y - index back from most recent (by 1 if bare minus)
2836 # N - go to that particular command slot or the last
2837 # thing if nothing following.
2838 $i = $minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist );
2840 # Pick out the command desired.
2843 # Print the command to be executed and restart the loop
2844 # with that command in the buffer.
2845 print $OUT $cmd, "\n";
2849 =head4 C<$sh$sh> - C<system()> command
2851 Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
2852 C<STDOUT> from getting messed up.
2856 # $sh$sh - run a shell command (if it's all ASCII).
2857 # Can't run shell commands with Unicode in the debugger, hmm.
2858 if (my ($arg) = $cmd =~ m#\A$sh$sh\s*(.*)#ms) {
2865 =head4 C<$rc I<pattern> $rc> - Search command history
2867 Another command to manipulate C<@hist>: this one searches it with a pattern.
2868 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
2872 # $rc pattern $rc - find a command in the history.
2873 if (my ($arg) = $cmd =~ /\A$rc([^$rc].*)\z/) {
2875 # Create the pattern to use.
2878 # Toss off last entry if length is >1 (and it always is).
2879 pop(@hist) if length($cmd) > 1;
2881 # Look backward through the history.
2882 for ( $i = $#hist ; $i ; --$i ) {
2883 # Stop if we find it.
2884 last if $hist[$i] =~ /$pat/;
2890 print $OUT "No such command!\n\n";
2894 # Found it. Put it in the buffer, print it, and process it.
2896 print $OUT $cmd, "\n";
2900 =head4 C<$sh> - Invoke a shell
2902 Uses C<DB::system> to invoke a shell.
2906 # $sh - start a shell.
2907 if ($cmd =~ /\A$sh\z/) {
2909 # Run the user's shell. If none defined, run Bourne.
2910 # We resume execution when the shell terminates.
2911 &system( $ENV{SHELL} || "/bin/sh" );
2915 =head4 C<$sh I<command>> - Force execution of a command in a shell
2917 Like the above, but the command is passed to the shell. Again, we use
2918 C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
2922 # $sh command - start a shell and run a command in it.
2923 if (my ($arg) = $cmd =~ m#\A$sh\s*(.*)#ms) {
2925 # XXX: using csh or tcsh destroys sigint retvals!
2926 #&system($1); # use this instead
2928 # use the user's shell, or Bourne if none defined.
2929 &system( $ENV{SHELL} || "/bin/sh", "-c", $arg );
2933 =head4 C<H> - display commands in history
2935 Prints the contents of C<@hist> (if any).
2939 if ($cmd =~ /\AH\b\s*\*/) {
2940 @hist = @truehist = ();
2941 print $OUT "History cleansed\n";
2946 = $cmd =~ /\AH\b\s*(?:-(\d+))?/) {
2948 # Anything other than negative numbers is ignored by
2949 # the (incorrect) pattern, so this test does nothing.
2950 $end = $num ? ( $#hist - $num ) : 0;
2952 # Set to the minimum if less than zero.
2953 $hist = 0 if $hist < 0;
2955 # Start at the end of the array.
2956 # Stay in while we're still above the ending value.
2957 # Tick back by one each time around the loop.
2958 for ( $i = $#hist ; $i > $end ; $i-- ) {
2960 # Print the command unless it has no arguments.
2961 print $OUT "$i: ", $hist[$i], "\n"
2962 unless $hist[$i] =~ /^.?$/;
2967 =head4 C<man, doc, perldoc> - look up documentation
2969 Just calls C<runman()> to print the appropriate document.
2973 # man, perldoc, doc - show manual pages.
2975 = $cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
2982 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
2983 the bottom of the loop.
2987 my $print_cmd = 'print {$DB::OUT} ';
2988 # p - print (no args): print $_.
2990 $cmd = $print_cmd . '$_';
2993 # p - print the given expression.
2994 $cmd =~ s/\Ap\b/$print_cmd /;
2996 =head4 C<=> - define command alias
2998 Manipulates C<%alias> to add or list command aliases.
3002 # = - set up a command alias.
3003 if ($cmd =~ s/\A=\s*//) {
3005 if ( length $cmd == 0 ) {
3007 # No args, get current aliases.
3008 @keys = sort keys %alias;
3010 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3012 # Creating a new alias. $k is alias name, $v is
3015 # can't use $_ or kill //g state
3016 for my $x ( $k, $v ) {
3018 # Escape "alarm" characters.
3022 # Substitute key for value, using alarm chars
3023 # as separators (which is why we escaped them in
3025 $alias{$k} = "s\a$k\a$v\a";
3027 # Turn off standard warn and die behavior.
3028 local $SIG{__DIE__};
3029 local $SIG{__WARN__};
3032 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3034 # Nope. Bad alias. Say so and get out.
3035 print $OUT "Can't alias $k to $v: $@\n";
3040 # We'll only list the new one.
3042 } ## end elsif (my ($k, $v) = ($cmd...
3044 # The argument is the alias to list.
3052 # Messy metaquoting: Trim the substitution code off.
3053 # We use control-G as the delimiter because it's not
3054 # likely to appear in the alias.
3055 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3058 print $OUT "$k\t= $1\n";
3060 elsif ( defined $alias{$k} ) {
3062 # Couldn't trim it off; just print the alias code.
3063 print $OUT "$k\t$alias{$k}\n";
3068 print "No alias for $k\n";
3070 } ## end for my $k (@keys)
3074 =head4 C<source> - read commands from a file.
3076 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3081 # source - read commands from a file (or pipe!) and execute.
3082 if (my ($sourced_fn) = $cmd =~ /\Asource\s+(.*\S)/) {
3083 if ( open my $fh, $sourced_fn ) {
3085 # Opened OK; stick it in the list of file handles.
3091 &warn("Can't execute '$sourced_fn': $!\n");
3096 if (my ($which_cmd, $position)
3097 = $cmd =~ /^(enable|disable)\s+(\S+)\s*$/) {
3099 my ($fn, $line_num);
3100 if ($position =~ m{\A\d+\z})
3103 $line_num = $position;
3105 elsif (my ($new_fn, $new_line_num)
3106 = $position =~ m{\A(.*):(\d+)\z}) {
3107 ($fn, $line_num) = ($new_fn, $new_line_num);
3111 &warn("Wrong spec for enable/disable argument.\n");
3115 if (_has_breakpoint_data_ref($fn, $line_num)) {
3116 _set_breakpoint_enabled_status($fn, $line_num,
3117 ($which_cmd eq 'enable' ? 1 : '')
3121 &warn("No breakpoint set at ${fn}:${line_num}\n");
3128 =head4 C<save> - send current history to a file
3130 Takes the complete history, (not the shrunken version you see with C<H>),
3131 and saves it to the given filename, so it can be replayed using C<source>.
3133 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3137 # save source - write commands to a file for later use
3138 if (my ($new_fn) = $cmd =~ /\Asave\s*(.*)\z/) {
3139 my $filename = $new_fn || '.perl5dbrc'; # default?
3140 if ( open my $fh, '>', $filename ) {
3142 # chomp to remove extraneous newlines from source'd files
3143 chomp( my @truelist =
3144 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3146 print $fh join( "\n", @truelist );
3147 print "commands saved in $file\n";
3150 &warn("Can't save debugger commands in '$new_fn': $!\n");
3155 =head4 C<R> - restart
3157 Restart the debugger session.
3159 =head4 C<rerun> - rerun the current session
3161 Return to any given position in the B<true>-history list
3165 # R - restart execution.
3166 # rerun - controlled restart execution.
3167 if (my ($cmd_cmd, $cmd_params) =
3168 $cmd =~ /\A((?:R)|(?:rerun\s*(.*)))\z/) {
3169 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
3171 # Close all non-system fds for a clean restart. A more
3172 # correct method would be to close all fds that were not
3173 # open when the process started, but this seems to be
3174 # hard. See "debugger 'R'estart and open database
3175 # connections" on p5p.
3177 my $max_fd = 1024; # default if POSIX can't be loaded
3178 if (eval { require POSIX }) {
3179 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
3182 if (defined $max_fd) {
3183 foreach ($^F+1 .. $max_fd-1) {
3184 next unless open FD_TO_CLOSE, "<&=$_";
3189 # And run Perl again. We use exec() to keep the
3190 # PID stable (and that way $ini_pids is still valid).
3191 exec(@args) || print $OUT "exec failed: $!\n";
3196 =head4 C<|, ||> - pipe output through the pager.
3198 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3199 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3200 pipe to the pager (restoring the output filehandles if this fails). If this
3201 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3202 set C<$signal>, sending us back into the debugger.
3204 We then trim off the pipe symbols and C<redo> the command loop at the
3205 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3210 # || - run command in the pager, with output to DB::OUT.
3211 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
3212 if ( $pager =~ /^\|/ ) {
3214 # Default pager is into a pipe. Redirect I/O.
3215 open( SAVEOUT, ">&STDOUT" )
3216 || &warn("Can't save STDOUT");
3217 open( STDOUT, ">&OUT" )
3218 || &warn("Can't redirect STDOUT");
3219 } ## end if ($pager =~ /^\|/)
3222 # Not into a pipe. STDOUT is safe.
3223 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3226 # Fix up environment to record we have less if so.
3229 unless ( $piped = open( OUT, $pager ) ) {
3231 # Couldn't open pipe to pager.
3232 &warn("Can't pipe output to '$pager'");
3233 if ( $pager =~ /^\|/ ) {
3235 # Redirect I/O back again.
3236 open( OUT, ">&STDOUT" ) # XXX: lost message
3237 || &warn("Can't restore DB::OUT");
3238 open( STDOUT, ">&SAVEOUT" )
3239 || &warn("Can't restore STDOUT");
3241 } ## end if ($pager =~ /^\|/)
3244 # Redirect I/O. STDOUT already safe.
3245 open( OUT, ">&STDOUT" ) # XXX: lost message
3246 || &warn("Can't restore DB::OUT");
3249 } ## end unless ($piped = open(OUT,...
3251 # Set up broken-pipe handler if necessary.
3252 $SIG{PIPE} = \&DB::catch
3254 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
3257 # Save current filehandle, and put it back.
3258 $selected = select(OUT);
3259 # Don't put it back if pager was a pipe.
3260 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
3262 # Trim off the pipe symbols and run the command now.
3263 $cmd =~ s#\A\|+\s*##;
3267 =head3 END OF COMMAND PARSING
3269 Anything left in C<$cmd> at this point is a Perl expression that we want to
3270 evaluate. We'll always evaluate in the user's context, and fully qualify
3271 any variables we might want to address in the C<DB> package.
3275 # t - turn trace on.
3276 if ($cmd =~ s#\At\s+(\d+)?#\$DB::trace |= 1;\n#) {
3278 $trace_to_depth = $trace_arg ? $stack_depth||0 + $1 : 1E9;
3281 # s - single-step. Remember the last command was 's'.
3282 if ($cmd =~ s/\As\s/\$DB::single = 1;\n/) {
3286 # n - single-step, but not into subs. Remember last command
3288 if ($cmd =~ s#\An\s#\$DB::single = 2;\n#) {
3294 # Make sure the flag that says "the debugger's running" is
3295 # still on, to make sure we get control again.
3296 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3298 # Run *our* eval that executes in the caller's context.
3301 # Turn off the one-time-dump stuff now.
3303 $onetimeDump = undef;
3304 $onetimedumpDepth = undef;
3306 elsif ( $term_pid == $$ ) {
3307 eval { # May run under miniperl, when not available...
3312 # XXX If this is the master pid, print a newline.
3315 } ## end while (($term || &setterm...
3317 =head3 POST-COMMAND PROCESSING
3319 After each command, we check to see if the command output was piped anywhere.
3320 If so, we go through the necessary code to unhook the pipe and go back to
3321 our standard filehandles for input and output.
3327 # At the end of every command:
3330 # Unhook the pipe mechanism now.
3331 if ( $pager =~ /^\|/ ) {
3333 # No error from the child.
3336 # we cannot warn here: the handle is missing --tchrist
3337 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
3339 # most of the $? crud was coping with broken cshisms
3340 # $? is explicitly set to 0, so this never runs.
3342 print SAVEOUT "Pager '$pager' failed: ";
3344 print SAVEOUT "shell returned -1\n";
3347 print SAVEOUT ( $? & 127 )
3348 ? " (SIG#" . ( $? & 127 ) . ")"
3349 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3352 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3356 # Reopen filehandle for our output (if we can) and
3357 # restore STDOUT (if we can).
3358 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3359 open( STDOUT, ">&SAVEOUT" )
3360 || &warn("Can't restore STDOUT");
3362 # Turn off pipe exception handler if necessary.
3363 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
3365 # Will stop ignoring SIGPIPE if done like nohup(1)
3366 # does SIGINT but Perl doesn't give us a choice.
3367 } ## end if ($pager =~ /^\|/)
3370 # Non-piped "pager". Just restore STDOUT.
3371 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3374 # Close filehandle pager was using, restore the normal one
3377 select($selected), $selected = "" unless $selected eq "";
3381 } ## end if ($piped)
3384 =head3 COMMAND LOOP TERMINATION
3386 When commands have finished executing, we come here. If the user closed the
3387 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3388 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3389 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3390 The interpreter will then execute the next line and then return control to us
3395 # No more commands? Quit.
3396 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
3398 # Evaluate post-prompt commands.
3399 foreach $evalarg (@$post) {
3402 } # if ($single || $signal)
3404 # Put the user's globals back where you found them.
3405 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3414 my $self = bless {}, $class;
3422 my ($self, $args) = @_;
3424 %{$self} = (%$self, %$args);
3431 foreach my $slot_name (qw(after explicit_stop infix position prefix)) {
3432 my $slot = $slot_name;
3437 ${ $self->{$slot} } = shift;
3440 return ${ $self->{$slot} };
3443 *{"append_to_$slot"} = sub {
3447 return $self->$slot($self->$slot . $s);
3452 sub _DB_on_init__initialize_globals
3456 # Check for whether we should be running continuously or not.
3457 # _After_ the perl program is compiled, $single is set to 1:
3458 if ( $DB::single and not $DB::second_time++ ) {
3460 # Options say run non-stop. Run until we get an interrupt.
3461 if ($DB::runnonstop) { # Disable until signal
3462 # If there's any call stack in place, turn off single
3463 # stepping into subs throughout the stack.
3464 for my $i (0 .. $DB::stack_depth) {
3465 $DB::stack[ $i ] &= ~1;
3468 # And we are now no longer in single-step mode.
3471 # If we simply returned at this point, we wouldn't get
3472 # the trace info. Fall on through.
3474 } ## end if ($runnonstop)
3476 elsif ($DB::ImmediateStop) {
3478 # We are supposed to stop here; XXX probably a break.
3479 $DB::ImmediateStop = 0; # We've processed it; turn it off
3480 $DB::signal = 1; # Simulate an interrupt to force
3481 # us into the command loop
3483 } ## end if ($single and not $second_time...
3485 # If we're in single-step mode, or an interrupt (real or fake)
3486 # has occurred, turn off non-stop mode.
3487 $DB::runnonstop = 0 if $DB::single or $DB::signal;
3492 sub _DB__handle_watch_expressions
3496 if ( $DB::trace & 2 ) {
3497 for my $n (0 .. $#DB::to_watch) {
3498 $DB::evalarg = $DB::to_watch[$n];
3499 local $DB::onetimeDump; # Tell DB::eval() to not output results
3501 # Fix context DB::eval() wants to return an array, but
3502 # we need a scalar here.
3503 my ($val) = join( "', '", DB::eval() );
3504 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
3507 if ( $val ne $DB::old_watch[$n] ) {
3509 # Yep! Show the difference, and fake an interrupt.
3511 print {$DB::OUT} <<EOP;
3512 Watchpoint $n:\t$DB::to_watch[$n] changed:
3513 old value:\t$DB::old_watch[$n]
3516 $DB::old_watch[$n] = $val;
3517 } ## end if ($val ne $old_watch...
3518 } ## end for my $n (0 ..
3519 } ## end if ($trace & 2)
3524 sub _my_print_lineinfo
3526 my ($self, $i, $incr_pos) = @_;
3529 # Print it indented if tracing is on.
3530 DB::print_lineinfo( ' ' x $DB::stack_depth,
3531 "$i:\t$DB::dbline[$i]" . $self->after );
3534 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3539 return $DB::dbline[$DB::line];
3542 sub _DB__grab_control
3546 # Yes, grab control.
3547 if ($DB::slave_editor) {
3549 # Tell the editor to update its position.
3550 $self->position("\032\032${DB::filename}:${DB::line}:0\n");
3551 DB::print_lineinfo($self->position());
3556 Special check: if we're in package C<DB::fake>, we've gone through the
3557 C<END> block at least once. We set up everything so that we can continue
3558 to enter commands and have a valid context to be in.
3562 elsif ( $DB::package eq 'DB::fake' ) {
3564 # Fallen off the end already.
3569 DB::print_help(<<EOP);
3570 Debugged program terminated. Use B<q> to quit or B<R> to restart,
3571 use B<o> I<inhibit_exit> to avoid stopping after program termination,
3572 B<h q>, B<h R> or B<h o> to get additional info.
3575 # Set the DB::eval context appropriately.
3576 $DB::package = 'main';
3577 $DB::usercontext = DB::_calc_usercontext($DB::package);
3578 } ## end elsif ($package eq 'DB::fake')
3582 If the program hasn't finished executing, we scan forward to the
3583 next executable line, print that out, build the prompt from the file and line
3584 number information, and print that.
3591 # Still somewhere in the midst of execution. Set up the
3593 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3594 # Perl 5 ones (sorry, we don't print Klingon
3597 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
3598 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
3599 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
3601 # Break up the prompt if it's really long.
3602 if ( length($self->prefix()) > 30 ) {
3603 $self->position($self->prefix . "$DB::line):\n$DB::line:\t" . $self->_curr_line . $self->after);
3605 $self->infix(":\t");
3608 $self->infix("):\t");
3610 $self->prefix . $DB::line. $self->infix
3611 . $self->_curr_line . $self->after
3615 # Print current line info, indenting if necessary.
3616 $self->_my_print_lineinfo($DB::line, $self->position);
3619 my $line_i = sub { return $DB::dbline[$i]; };
3621 # Scan forward, stopping at either the end or the next
3623 for ( $i = $DB::line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
3626 # Drop out on null statements, block closers, and comments.
3627 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
3629 # Drop out if the user interrupted us.
3630 last if $DB::signal;
3632 # Append a newline if the line doesn't have one. Can happen
3633 # in eval'ed text, for instance.
3634 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
3636 # Next executable line.
3637 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
3639 $self->append_to_position($incr_pos);
3640 $self->_my_print_lineinfo($i, $incr_pos);
3641 } ## end for ($i = $line + 1 ; $i...
3642 } ## end else [ if ($slave_editor)
3647 sub _handle_t_command {
3648 if (my ($levels) = $DB::cmd =~ /\At(?:\s+(\d+))?\z/) {
3651 $DB::trace_to_depth = $levels ? $DB::stack_depth + $levels : 1E9;
3652 print {$DB::OUT} "Trace = "
3653 . ( ( $DB::trace & 1 )
3654 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3664 # The following code may be executed now:
3669 C<sub> is called whenever a subroutine call happens in the program being
3670 debugged. The variable C<$DB::sub> contains the name of the subroutine
3673 The core function of this subroutine is to actually call the sub in the proper
3674 context, capturing its output. This of course causes C<DB::DB> to get called
3675 again, repeating until the subroutine ends and returns control to C<DB::sub>
3676 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3677 return value, and returns its captured copy of the return value as its own
3678 return value. The value then feeds back into the program being debugged as if
3679 C<DB::sub> hadn't been there at all.
3681 C<sub> does all the work of printing the subroutine entry and exit messages
3682 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3683 and also prints the return value if needed (for the C<r> command and if
3684 the 16 bit is set in C<$frame>).
3686 It also tracks the subroutine call depth by saving the current setting of
3687 C<$single> in the C<@stack> package global; if this exceeds the value in
3688 C<$deep>, C<sub> automatically turns on printing of the current depth by
3689 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
3690 of stop/don't stop on entry to subs set as it currently is set.
3692 =head3 C<caller()> support
3694 If C<caller()> is called from the package C<DB>, it provides some
3695 additional data, in the following order:
3701 The package name the sub was in
3703 =item * C<$filename>
3705 The filename it was defined in
3709 The line number it was defined on
3711 =item * C<$subroutine>
3713 The subroutine name; C<(eval)> if an C<eval>().
3717 1 if it has arguments, 0 if not
3719 =item * C<$wantarray>
3721 1 if array context, 0 if scalar context
3723 =item * C<$evaltext>
3725 The C<eval>() text, if any (undefined for C<eval BLOCK>)
3727 =item * C<$is_require>
3729 frame was created by a C<use> or C<require> statement
3733 pragma information; subject to change between versions
3737 pragma information; subject to change between versions
3739 =item * C<@DB::args>
3741 arguments with which the subroutine was invoked
3749 # We need to fully qualify the name ("DB::sub") to make "use strict;"
3750 # happy. -- Shlomi Fish
3752 # Do not use a regex in this subroutine -> results in corrupted memory
3753 # See: [perl #66110]
3755 # lock ourselves under threads
3758 # Whether or not the autoloader was running, a scalar to put the
3759 # sub's return value in (if needed), and an array to put the sub's
3760 # return value in (if needed).
3761 my ( $al, $ret, @ret ) = "";
3762 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) {
3763 print "creating new thread\n";
3766 # If the last ten characters are '::AUTOLOAD', note we've traced
3767 # into AUTOLOAD for $sub.
3768 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3770 $al = " for $$sub" if defined $$sub;
3773 # We stack the stack pointer and then increment it to protect us
3774 # from a situation that might unwind a whole bunch of call frames
3775 # at once. Localizing the stack pointer means that it will automatically
3776 # unwind the same amount when multiple stack frames are unwound.
3777 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3780 $#stack = $stack_depth;
3782 # Save current single-step setting.
3783 $stack[-1] = $single;
3785 # Turn off all flags except single-stepping.
3788 # If we've gotten really deeply recursed, turn on the flag that will
3789 # make us stop with the 'deep recursion' message.
3790 $single |= 4 if $stack_depth == $deep;
3792 # If frame messages are on ...
3794 $frame & 4 # Extended frame entry message
3796 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3798 # Why -1? But it works! :-(
3799 # Because print_trace will call add 1 to it and then call
3800 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3802 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3804 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3806 # standard frame entry message
3810 # Determine the sub's return type, and capture appropriately.
3813 # Called in array context. call sub and capture output.
3814 # DB::DB will recursively get control again if appropriate; we'll come
3815 # back here when the sub is finished.
3821 # Pop the single-step value back off the stack.
3822 $single |= $stack[ $stack_depth-- ];
3824 # Check for exit trace messages...
3826 $frame & 4 # Extended exit message
3828 print_lineinfo( ' ' x $stack_depth, "out " ),
3829 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3831 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3833 # Standard exit message
3837 # Print the return info if we need to.
3838 if ( $doret eq $stack_depth or $frame & 16 ) {
3840 # Turn off output record separator.
3842 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3844 # Indent if we're printing because of $frame tracing.
3845 print $fh ' ' x $stack_depth if $frame & 16;
3847 # Print the return value.
3848 print $fh "list context return from $sub:\n";
3849 dumpit( $fh, \@ret );
3851 # And don't print it again.
3853 } ## end if ($doret eq $stack_depth...
3854 # And we have to return the return value now.
3856 } ## end if (wantarray)
3860 if ( defined wantarray ) {
3862 # Save the value if it's wanted at all.
3867 # Void return, explicitly.
3872 # Pop the single-step value off the stack.
3873 $single |= $stack[ $stack_depth-- ];
3875 # If we're doing exit messages...
3877 $frame & 4 # Extended messages
3879 print_lineinfo( ' ' x $stack_depth, "out " ),
3880 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3882 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3888 # If we are supposed to show the return value... same as before.
3889 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
3891 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
3892 print $fh ( ' ' x $stack_depth ) if $frame & 16;
3895 ? "scalar context return from $sub: "
3896 : "void context return from $sub\n"
3898 dumpit( $fh, $ret ) if defined wantarray;
3900 } ## end if ($doret eq $stack_depth...
3902 # Return the appropriate scalar value.
3904 } ## end else [ if (wantarray)
3911 # lock ourselves under threads
3914 # Whether or not the autoloader was running, a scalar to put the
3915 # sub's return value in (if needed), and an array to put the sub's
3916 # return value in (if needed).
3917 my ( $al, $ret, @ret ) = "";
3918 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
3919 print "creating new thread\n";
3922 # If the last ten characters are C'::AUTOLOAD', note we've traced
3923 # into AUTOLOAD for $sub.
3924 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3928 # We stack the stack pointer and then increment it to protect us
3929 # from a situation that might unwind a whole bunch of call frames
3930 # at once. Localizing the stack pointer means that it will automatically
3931 # unwind the same amount when multiple stack frames are unwound.
3932 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
3935 $#stack = $stack_depth;
3937 # Save current single-step setting.
3938 $stack[-1] = $single;
3940 # Turn off all flags except single-stepping.
3943 # If we've gotten really deeply recursed, turn on the flag that will
3944 # make us stop with the 'deep recursion' message.
3945 $single |= 4 if $stack_depth == $deep;
3947 # If frame messages are on ...
3949 $frame & 4 # Extended frame entry message
3951 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
3953 # Why -1? But it works! :-(
3954 # Because print_trace will call add 1 to it and then call
3955 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3957 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3959 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3961 # standard frame entry message
3965 # Pop the single-step value back off the stack.
3966 $single |= $stack[ $stack_depth-- ];
3968 # call the original lvalue sub.
3972 # Abstracting common code from multiple places elsewhere:
3973 sub depth_print_lineinfo {
3974 my $always_print = shift;
3976 print_lineinfo( @_ ) if ($always_print or $stack_depth < $trace_to_depth);
3979 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
3981 In Perl 5.8.0, there was a major realignment of the commands and what they did,
3982 Most of the changes were to systematize the command structure and to eliminate
3983 commands that threw away user input without checking.
3985 The following sections describe the code added to make it easy to support
3986 multiple command sets with conflicting command names. This section is a start
3987 at unifying all command processing to make it simpler to develop commands.
3989 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
3990 number, and C<$dbline> (the current line) as arguments.
3992 Support functions in this section which have multiple modes of failure C<die>
3993 on error; the rest simply return a false value.
3995 The user-interface functions (all of the C<cmd_*> functions) just output
4000 The C<%set> hash defines the mapping from command letter to subroutine
4003 C<%set> is a two-level hash, indexed by set name and then by command name.
4004 Note that trying to set the CommandSet to C<foobar> simply results in the
4005 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
4014 'A' => 'pre580_null',
4016 'B' => 'pre580_null',
4017 'd' => 'pre580_null',
4020 'M' => 'pre580_null',
4022 'o' => 'pre580_null',
4028 '<' => 'pre590_prepost',
4029 '<<' => 'pre590_prepost',
4030 '>' => 'pre590_prepost',
4031 '>>' => 'pre590_prepost',
4032 '{' => 'pre590_prepost',
4033 '{{' => 'pre590_prepost',
4037 my %breakpoints_data;
4039 sub _has_breakpoint_data_ref {
4040 my ($filename, $line) = @_;
4043 exists( $breakpoints_data{$filename} )
4045 exists( $breakpoints_data{$filename}{$line} )
4049 sub _get_breakpoint_data_ref {
4050 my ($filename, $line) = @_;
4052 return ($breakpoints_data{$filename}{$line} ||= +{});
4055 sub _delete_breakpoint_data_ref {
4056 my ($filename, $line) = @_;
4058 delete($breakpoints_data{$filename}{$line});
4059 if (! scalar(keys( %{$breakpoints_data{$filename}} )) ) {
4060 delete($breakpoints_data{$filename});
4066 sub _set_breakpoint_enabled_status {
4067 my ($filename, $line, $status) = @_;
4069 _get_breakpoint_data_ref($filename, $line)->{'enabled'} =
4076 sub _enable_breakpoint_temp_enabled_status {
4077 my ($filename, $line) = @_;
4079 _get_breakpoint_data_ref($filename, $line)->{'temp_enabled'} = 1;
4084 sub _cancel_breakpoint_temp_enabled_status {
4085 my ($filename, $line) = @_;
4087 my $ref = _get_breakpoint_data_ref($filename, $line);
4089 delete ($ref->{'temp_enabled'});
4092 _delete_breakpoint_data_ref($filename, $line);
4098 sub _is_breakpoint_enabled {
4099 my ($filename, $line) = @_;
4101 my $data_ref = _get_breakpoint_data_ref($filename, $line);
4102 return ($data_ref->{'enabled'} || $data_ref->{'temp_enabled'});
4105 =head2 C<cmd_wrapper()> (API)
4107 C<cmd_wrapper()> allows the debugger to switch command sets
4108 depending on the value of the C<CommandSet> option.
4110 It tries to look up the command in the C<%set> package-level I<lexical>
4111 (which means external entities can't fiddle with it) and create the name of
4112 the sub to call based on the value found in the hash (if it's there). I<All>
4113 of the commands to be handled in a set have to be added to C<%set>; if they
4114 aren't found, the 5.8.0 equivalent is called (if there is one).
4116 This code uses symbolic references.
4123 my $dblineno = shift;
4125 # Assemble the command subroutine's name by looking up the
4126 # command set and command name in %set. If we can't find it,
4127 # default to the older version of the command.
4129 . ( $set{$CommandSet}{$cmd}
4130 || ( $cmd =~ /^[<>{]+/o ? 'prepost' : $cmd ) );
4132 # Call the command subroutine, call it by name.
4133 return __PACKAGE__->can($call)->( $cmd, $line, $dblineno );
4134 } ## end sub cmd_wrapper
4136 =head3 C<cmd_a> (command)
4138 The C<a> command handles pre-execution actions. These are associated with a
4139 particular line, so they're stored in C<%dbline>. We default to the current
4140 line if none is specified.
4146 my $line = shift || ''; # [.|line] expr
4149 # If it's dot (here), or not all digits, use the current line.
4150 $line =~ s/^(\.|(?:[^\d]))/$dbline/;
4152 # Should be a line number followed by an expression.
4153 if ( $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
4154 my ( $lineno, $expr ) = ( $1, $2 );
4156 # If we have an expression ...
4157 if ( length $expr ) {
4159 # ... but the line isn't breakable, complain.
4160 if ( $dbline[$lineno] == 0 ) {
4162 "Line $lineno($dbline[$lineno]) does not have an action?\n";
4166 # It's executable. Record that the line has an action.
4167 $had_breakpoints{$filename} |= 2;
4169 # Remove any action, temp breakpoint, etc.
4170 $dbline{$lineno} =~ s/\0[^\0]*//;
4172 # Add the action to the line.
4173 $dbline{$lineno} .= "\0" . action($expr);
4175 _set_breakpoint_enabled_status($filename, $lineno, 1);
4177 } ## end if (length $expr)
4178 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
4183 "Adding an action requires an optional lineno and an expression\n"
4188 =head3 C<cmd_A> (command)
4190 Delete actions. Similar to above, except the delete code is in a separate
4191 subroutine, C<delete_action>.
4197 my $line = shift || '';
4201 $line =~ s/^\./$dbline/;
4203 # Call delete_action with a null param to delete them all.
4204 # The '1' forces the eval to be true. It'll be false only
4205 # if delete_action blows up for some reason, in which case
4206 # we print $@ and get out.
4207 if ( $line eq '*' ) {
4208 if (! eval { _delete_all_actions(); 1 }) {
4214 # There's a real line number. Pass it to delete_action.
4215 # Error trapping is as above.
4216 elsif ( $line =~ /^(\S.*)/ ) {
4217 if (! eval { delete_action($1); 1 }) {
4223 # Swing and a miss. Bad syntax.
4226 "Deleting an action requires a line number, or '*' for all\n" ; # hint
4230 =head3 C<delete_action> (API)
4232 C<delete_action> accepts either a line number or C<undef>. If a line number
4233 is specified, we check for the line being executable (if it's not, it
4234 couldn't have had an action). If it is, we just take the action off (this
4235 will get any kind of an action, including breakpoints).
4239 sub _remove_action_from_dbline {
4242 $dbline{$i} =~ s/\0[^\0]*//; # \^a
4243 delete $dbline{$i} if $dbline{$i} eq '';
4248 sub _delete_all_actions {
4249 print {$OUT} "Deleting all actions...\n";
4251 for my $file ( keys %had_breakpoints ) {
4252 local *dbline = $main::{ '_<' . $file };
4255 for my $i (1 .. $max) {
4256 if ( defined $dbline{$i} ) {
4257 _remove_action_from_dbline($i);
4261 unless ( $had_breakpoints{$file} &= ~2 ) {
4262 delete $had_breakpoints{$file};
4272 if ( defined($i) ) {
4274 die "Line $i has no action .\n" if $dbline[$i] == 0;
4276 # Nuke whatever's there.
4277 _remove_action_from_dbline($i);
4280 _delete_all_actions();
4284 =head3 C<cmd_b> (command)
4286 Set breakpoints. Since breakpoints can be set in so many places, in so many
4287 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4288 we try to parse the command type, and then shuttle it off to an appropriate
4289 subroutine to actually do the work of setting the breakpoint in the right
4296 my $line = shift; # [.|line] [cond]
4299 my $default_cond = sub {
4301 return length($cond) ? $cond : '1';
4304 # Make . the current line number if it's there..
4305 $line =~ s/^\.(\s|\z)/$dbline$1/;
4307 # No line number, no condition. Simple break on current line.
4308 if ( $line =~ /^\s*$/ ) {
4309 cmd_b_line( $dbline, 1 );
4312 # Break on load for a file.
4313 elsif ( my ($file) = $line =~ /^load\b\s*(.*)/ ) {
4318 # b compile|postpone <some sub> [<condition>]
4319 # The interpreter actually traps this one for us; we just put the
4320 # necessary condition in the %postponed hash.
4321 elsif ( my ($action, $subname, $cond)
4322 = $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4324 # De-Perl4-ify the name - ' separators to ::.
4325 $subname =~ s/'/::/g;
4327 # Qualify it into the current package unless it's already qualified.
4328 $subname = "${package}::" . $subname unless $subname =~ /::/;
4330 # Add main if it starts with ::.
4331 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4333 # Save the break type for this sub.
4334 $postponed{$subname} = (($action eq 'postpone')
4335 ? ( "break +0 if " . $default_cond->($cond) )
4337 } ## end elsif ($line =~ ...
4338 # b <filename>:<line> [<condition>]
4339 elsif (my ($filename, $line_num, $cond)
4340 = $line =~ /\A(\S+[^:]):(\d+)\s*(.*)/ms) {
4341 cmd_b_filename_line(
4344 (length($cond) ? $cond : '1'),
4347 # b <sub name> [<condition>]
4348 elsif ( my ($new_subname, $new_cond) =
4349 $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4352 $subname = $new_subname;
4353 cmd_b_sub( $subname, $default_cond->($new_cond) );
4356 # b <line> [<condition>].
4357 elsif ( my ($line_n, $cond) = $line =~ /^(\d*)\s*(.*)/ ) {
4359 # Capture the line. If none, it's the current line.
4360 $line = $line_n || $dbline;
4363 cmd_b_line( $line, $default_cond->($cond) );
4366 # Line didn't make sense.
4368 print "confused by line($line)?\n";
4374 =head3 C<break_on_load> (API)
4376 We want to break when this file is loaded. Mark this file in the
4377 C<%break_on_load> hash, and note that it has a breakpoint in
4378 C<%had_breakpoints>.
4384 $break_on_load{$file} = 1;
4385 $had_breakpoints{$file} |= 1;
4388 =head3 C<report_break_on_load> (API)
4390 Gives us an array of filenames that are set to break on load. Note that
4391 only files with break-on-load are in here, so simply showing the keys
4396 sub report_break_on_load {
4397 sort keys %break_on_load;
4400 =head3 C<cmd_b_load> (command)
4402 We take the file passed in and try to find it in C<%INC> (which maps modules
4403 to files they came from). We mark those files for break-on-load via
4404 C<break_on_load> and then report that it was done.
4412 # This is a block because that way we can use a redo inside it
4413 # even without there being any looping structure at all outside it.
4416 # Save short name and full path if found.
4418 push @files, $::INC{$file} if $::INC{$file};
4420 # Tack on .pm and do it again unless there was a '.' in the name
4422 $file .= '.pm', redo unless $file =~ /\./;
4425 # Do the real work here.
4426 break_on_load($_) for @files;
4428 # All the files that have break-on-load breakpoints.
4429 @files = report_break_on_load;
4431 # Normalize for the purposes of our printing this.
4434 print $OUT "Will stop on load of '@files'.\n";
4435 } ## end sub cmd_b_load
4437 =head3 C<$filename_error> (API package global)
4439 Several of the functions we need to implement in the API need to work both
4440 on the current file and on other files. We don't want to duplicate code, so
4441 C<$filename_error> is used to contain the name of the file that's being
4442 worked on (if it's not the current one).
4444 We can now build functions in pairs: the basic function works on the current
4445 file, and uses C<$filename_error> as part of its error message. Since this is
4446 initialized to C<"">, no filename will appear when we are working on the
4449 The second function is a wrapper which does the following:
4455 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4459 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4463 Calls the first function.
4465 The first function works on the I<current> file (i.e., the one we changed to),
4466 and prints C<$filename_error> in the error message (the name of the other file)
4467 if it needs to. When the functions return, C<*dbline> is restored to point
4468 to the actual current file (the one we're executing in) and
4469 C<$filename_error> is restored to C<"">. This restores everything to
4470 the way it was before the second function was called at all.
4472 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4479 use vars qw($filename_error);
4480 $filename_error = '';
4482 =head3 breakable_line(from, to) (API)
4484 The subroutine decides whether or not a line in the current file is breakable.
4485 It walks through C<@dbline> within the range of lines specified, looking for
4486 the first line that is breakable.
4488 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4489 first line I<after> C<$to> that's breakable, if there is one.
4491 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4492 first line I<before> C<$to> that's breakable, if there is one.
4496 sub breakable_line {
4498 my ( $from, $to ) = @_;
4500 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4503 # If there are at least 2 arguments, we're trying to search a range.
4506 # $delta is positive for a forward search, negative for a backward one.
4507 my $delta = $from < $to ? +1 : -1;
4509 # Keep us from running off the ends of the file.
4510 my $limit = $delta > 0 ? $#dbline : 1;
4512 # Clever test. If you're a mathematician, it's obvious why this
4513 # test works. If not:
4514 # If $delta is positive (going forward), $limit will be $#dbline.
4515 # If $to is less than $limit, ($limit - $to) will be positive, times
4516 # $delta of 1 (positive), so the result is > 0 and we should use $to
4517 # as the stopping point.
4519 # If $to is greater than $limit, ($limit - $to) is negative,
4520 # times $delta of 1 (positive), so the result is < 0 and we should
4521 # use $limit ($#dbline) as the stopping point.
4523 # If $delta is negative (going backward), $limit will be 1.
4524 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4525 # (negative) so the result is > 0, and we use $to as the stopping
4528 # If $to is less than zero, ($limit - $to) will be positive,
4529 # times $delta of -1 (negative), so the result is not > 0, and
4530 # we use $limit (1) as the stopping point.
4532 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4533 # (negative), still giving zero; the result is not > 0, and
4534 # we use $limit (1) as the stopping point.
4536 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4537 # (negative), giving a positive (>0) value, so we'll set $limit to
4540 $limit = $to if ( $limit - $to ) * $delta > 0;
4542 # The real search loop.
4543 # $i starts at $from (the point we want to start searching from).
4544 # We move through @dbline in the appropriate direction (determined
4545 # by $delta: either -1 (back) or +1 (ahead).
4546 # We stay in as long as we haven't hit an executable line
4547 # ($dbline[$i] == 0 means not executable) and we haven't reached
4548 # the limit yet (test similar to the above).
4549 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4551 } ## end if (@_ >= 2)
4553 # If $i points to a line that is executable, return that.
4554 return $i unless $dbline[$i] == 0;
4556 # Format the message and print it: no breakable lines in range.
4557 my ( $pl, $upto ) = ( '', '' );
4558 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4560 # If there's a filename in filename_error, we'll see it.
4562 die "Line$pl $from$upto$filename_error not breakable\n";
4563 } ## end sub breakable_line
4565 =head3 breakable_line_in_filename(file, from, to) (API)
4567 Like C<breakable_line>, but look in another file.
4571 sub breakable_line_in_filename {
4573 # Capture the file name.
4576 # Swap the magic line array over there temporarily.
4577 local *dbline = $main::{ '_<' . $f };
4579 # If there's an error, it's in this other file.
4580 local $filename_error = " of '$f'";
4582 # Find the breakable line.
4585 # *dbline and $filename_error get restored when this block ends.
4587 } ## end sub breakable_line_in_filename
4589 =head3 break_on_line(lineno, [condition]) (API)
4591 Adds a breakpoint with the specified condition (or 1 if no condition was
4592 specified) to the specified line. Dies if it can't.
4598 my $cond = @_ ? shift(@_) : 1;
4604 # Woops, not a breakable line. $filename_error allows us to say
4605 # if it was in a different file.
4606 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4608 # Mark this file as having breakpoints in it.
4609 $had_breakpoints{$filename} |= 1;
4611 # If there is an action or condition here already ...
4612 if ( $dbline{$i} ) {
4614 # ... swap this condition for the existing one.
4615 $dbline{$i} =~ s/^[^\0]*/$cond/;
4619 # Nothing here - just add the condition.
4620 $dbline{$i} = $cond;
4622 _set_breakpoint_enabled_status($filename, $i, 1);
4626 } ## end sub break_on_line
4628 =head3 cmd_b_line(line, [condition]) (command)
4630 Wrapper for C<break_on_line>. Prints the failure message if it
4636 if (not eval { break_on_line(@_); 1 }) {
4638 print $OUT $@ and return;
4642 } ## end sub cmd_b_line
4644 =head3 cmd_b_filename_line(line, [condition]) (command)
4646 Wrapper for C<break_on_filename_line>. Prints the failure message if it
4651 sub cmd_b_filename_line {
4652 if (not eval { break_on_filename_line(@_); 1 }) {
4654 print $OUT $@ and return;
4660 =head3 break_on_filename_line(file, line, [condition]) (API)
4662 Switches to the file specified and then calls C<break_on_line> to set
4667 sub break_on_filename_line {
4670 my $cond = @_ ? shift(@_) : 1;
4672 # Switch the magical hash temporarily.
4673 local *dbline = $main::{ '_<' . $f };
4675 # Localize the variables that break_on_line uses to make its message.
4676 local $filename_error = " of '$f'";
4677 local $filename = $f;
4679 # Add the breakpoint.
4680 break_on_line( $i, $cond );
4683 } ## end sub break_on_filename_line
4685 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
4687 Switch to another file, search the range of lines specified for an
4688 executable one, and put a breakpoint on the first one you find.
4692 sub break_on_filename_line_range {
4696 my $cond = @_ ? shift(@_) : 1;
4698 # Find a breakable line if there is one.
4699 my $i = breakable_line_in_filename( $f, $from, $to );
4701 # Add the breakpoint.
4702 break_on_filename_line( $f, $i, $cond );
4705 } ## end sub break_on_filename_line_range
4707 =head3 subroutine_filename_lines(subname, [condition]) (API)
4709 Search for a subroutine within a given file. The condition is ignored.
4710 Uses C<find_sub> to locate the desired subroutine.
4714 sub subroutine_filename_lines {
4715 my ( $subname ) = @_;
4717 # Returned value from find_sub() is fullpathname:startline-endline.
4718 # The match creates the list (fullpathname, start, end).
4719 return (find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/);
4720 } ## end sub subroutine_filename_lines
4722 =head3 break_subroutine(subname) (API)
4724 Places a break on the first line possible in the specified subroutine. Uses
4725 C<subroutine_filename_lines> to find the subroutine, and
4726 C<break_on_filename_line_range> to place the break.
4730 sub break_subroutine {
4731 my $subname = shift;
4733 # Get filename, start, and end.
4734 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
4735 or die "Subroutine $subname not found.\n";
4738 # Null condition changes to '1' (always true).
4739 my $cond = @_ ? shift(@_) : 1;
4741 # Put a break the first place possible in the range of lines
4742 # that make up this subroutine.
4743 break_on_filename_line_range( $file, $s, $e, $cond );
4746 } ## end sub break_subroutine
4748 =head3 cmd_b_sub(subname, [condition]) (command)
4750 We take the incoming subroutine name and fully-qualify it as best we can.
4754 =item 1. If it's already fully-qualified, leave it alone.
4756 =item 2. Try putting it in the current package.
4758 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
4760 =item 4. If it starts with '::', put it in 'main::'.
4764 After all this cleanup, we call C<break_subroutine> to try to set the
4770 my ( $subname, $cond ) = @_;
4772 # Add always-true condition if we have none.
4773 $cond = 1 unless @_ >= 2;
4775 # If the subname isn't a code reference, qualify it so that
4776 # break_subroutine() will work right.
4777 unless ( ref $subname eq 'CODE' ) {
4780 $subname =~ s/\'/::/g;
4783 # Put it in this package unless it's already qualified.
4784 $subname = "${package}::" . $subname
4785 unless $subname =~ /::/;
4787 # Requalify it into CORE::GLOBAL if qualifying it into this
4788 # package resulted in its not being defined, but only do so
4789 # if it really is in CORE::GLOBAL.
4790 $subname = "CORE::GLOBAL::$s"
4791 if not defined &$subname
4793 and defined &{"CORE::GLOBAL::$s"};
4795 # Put it in package 'main' if it has a leading ::.
4796 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4798 } ## end unless (ref $subname eq 'CODE')
4800 # Try to set the breakpoint.
4801 if (not eval { break_subroutine( $subname, $cond ); 1 }) {
4803 print $OUT $@ and return;
4807 } ## end sub cmd_b_sub
4809 =head3 C<cmd_B> - delete breakpoint(s) (command)
4811 The command mostly parses the command line and tries to turn the argument
4812 into a line spec. If it can't, it uses the current line. It then calls
4813 C<delete_breakpoint> to actually do the work.
4815 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
4816 thereby deleting all the breakpoints.
4823 # No line spec? Use dbline.
4824 # If there is one, use it if it's non-zero, or wipe it out if it is.
4825 my $line = ( $_[0] =~ /\A\./ ) ? $dbline : (shift || '');
4828 # If the line was dot, make the line the current one.
4829 $line =~ s/^\./$dbline/;
4831 # If it's * we're deleting all the breakpoints.
4832 if ( $line eq '*' ) {
4833 if (not eval { delete_breakpoint(); 1 }) {
4838 # If there is a line spec, delete the breakpoint on that line.
4839 elsif ( $line =~ /\A(\S.*)/ ) {
4840 if (not eval { delete_breakpoint( $line || $dbline ); 1 }) {
4844 } ## end elsif ($line =~ /^(\S.*)/)
4849 "Deleting a breakpoint requires a line number, or '*' for all\n"
4856 =head3 delete_breakpoint([line]) (API)
4858 This actually does the work of deleting either a single breakpoint, or all
4861 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
4862 just drop out with a message saying so. If it is, we remove the condition
4863 part of the 'condition\0action' that says there's a breakpoint here. If,
4864 after we've done that, there's nothing left, we delete the corresponding
4865 line in C<%dbline> to signal that no action needs to be taken for this line.
4867 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
4868 which lists all currently-loaded files which have breakpoints. We then look
4869 at each line in each of these files, temporarily switching the C<%dbline>
4870 and C<@dbline> structures to point to the files in question, and do what
4871 we did in the single line case: delete the condition in C<@dbline>, and
4872 delete the key in C<%dbline> if nothing's left.
4874 We then wholesale delete C<%postponed>, C<%postponed_file>, and
4875 C<%break_on_load>, because these structures contain breakpoints for files
4876 and code that haven't been loaded yet. We can just kill these off because there
4877 are no magical debugger structures associated with them.
4881 sub _remove_breakpoint_entry {
4885 _delete_breakpoint_data_ref($fn, $i);
4890 sub _delete_all_breakpoints {
4891 print {$OUT} "Deleting all breakpoints...\n";
4893 # %had_breakpoints lists every file that had at least one
4895 for my $fn ( keys %had_breakpoints ) {
4897 # Switch to the desired file temporarily.
4898 local *dbline = $main::{ '_<' . $fn };
4902 # For all lines in this file ...
4903 for my $i (1 .. $max) {
4905 # If there's a breakpoint or action on this line ...
4906 if ( defined $dbline{$i} ) {
4908 # ... remove the breakpoint.
4909 $dbline{$i} =~ s/\A[^\0]+//;
4910 if ( $dbline{$i} =~ s/\A\0?\z// ) {
4911 # Remove the entry altogether if no action is there.
4912 _remove_breakpoint_entry($fn, $i);
4914 } ## end if (defined $dbline{$i...
4915 } ## end for $i (1 .. $max)
4917 # If, after we turn off the "there were breakpoints in this file"
4918 # bit, the entry in %had_breakpoints for this file is zero,
4919 # we should remove this file from the hash.
4920 if ( not $had_breakpoints{$fn} &= (~1) ) {
4921 delete $had_breakpoints{$fn};
4923 } ## end for my $fn (keys %had_breakpoints)
4925 # Kill off all the other breakpoints that are waiting for files that
4926 # haven't been loaded yet.
4928 undef %postponed_file;
4929 undef %break_on_load;
4934 sub _delete_breakpoint_from_line {
4937 # Woops. This line wasn't breakable at all.
4938 die "Line $i not breakable.\n" if $dbline[$i] == 0;
4940 # Kill the condition, but leave any action.
4941 $dbline{$i} =~ s/\A[^\0]*//;
4943 # Remove the entry entirely if there's no action left.
4944 if ($dbline{$i} eq '') {
4945 _remove_breakpoint_entry($filename, $i);
4951 sub delete_breakpoint {
4954 # If we got a line, delete just that one.
4955 if ( defined($i) ) {
4956 _delete_breakpoint_from_line($i);
4958 # No line; delete them all.
4960 _delete_all_breakpoints();
4966 =head3 cmd_stop (command)
4968 This is meant to be part of the new command API, but it isn't called or used
4969 anywhere else in the debugger. XXX It is probably meant for use in development
4974 sub cmd_stop { # As on ^C, but not signal-safy.
4978 =head3 C<cmd_e> - threads
4980 Display the current thread id:
4984 This could be how (when implemented) to send commands to this thread id (e cmd)
4985 or that thread id (e tid cmd).
4992 unless (exists($INC{'threads.pm'})) {
4993 print "threads not loaded($ENV{PERL5DB_THREADED})
4994 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
4996 my $tid = threads->tid;
4997 print "thread id: $tid\n";
5001 =head3 C<cmd_E> - list of thread ids
5003 Display the list of available thread ids:
5007 This could be used (when implemented) to send commands to all threads (E cmd).
5014 unless (exists($INC{'threads.pm'})) {
5015 print "threads not loaded($ENV{PERL5DB_THREADED})
5016 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5018 my $tid = threads->tid;
5019 print "thread ids: ".join(', ',
5020 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
5025 =head3 C<cmd_h> - help command (command)
5027 Does the work of either
5033 Showing all the debugger help
5037 Showing help for a specific command
5044 use vars qw($summary);
5049 # If we have no operand, assume null.
5050 my $line = shift || '';
5052 # 'h h'. Print the long-format help.
5053 if ( $line =~ /\Ah\s*\z/ ) {
5057 # 'h <something>'. Search for the command and print only its help.
5058 elsif ( my ($asked) = $line =~ /\A(\S.*)\z/ ) {
5060 # support long commands; otherwise bogus errors
5061 # happen when you ask for h on <CR> for example
5062 my $qasked = quotemeta($asked); # for searching; we don't
5063 # want to use it as a pattern.
5064 # XXX: finds CR but not <CR>
5066 # Search the help string for the command.
5068 $help =~ /^ # Start of a line
5070 (?:[IB]<) # Optional markup
5071 $qasked # The requested command
5076 # It's there; pull it out and print it.
5080 (?:[IB]<) # Optional markup
5081 $qasked # The command
5082 ([\s\S]*?) # Description line(s)
5083 \n) # End of last description line
5084 (?!\s) # Next line not starting with
5093 # Not found; not a debugger command.
5095 print_help("B<$asked> is not a debugger command.\n");
5097 } ## end elsif ($line =~ /^(\S.*)$/)
5099 # 'h' - print the summary help.
5101 print_help($summary);
5105 =head3 C<cmd_i> - inheritance display
5107 Display the (nested) parentage of the module or object given.
5114 foreach my $isa ( split( /\s+/, $line ) ) {
5116 ($isa) = DB::eval();
5123 defined( ${"$_\::VERSION"} )
5124 ? ' ' . ${"$_\::VERSION"}
5126 } @{mro::get_linear_isa(ref($isa) || $isa)}
5132 =head3 C<cmd_l> - list lines (command)
5134 Most of the command is taken up with transforming all the different line
5135 specification syntaxes into 'start-stop'. After that is done, the command
5136 runs a loop over C<@dbline> for the specified range of lines. It handles
5137 the printing of each line and any markers (C<==E<gt>> for current line,
5138 C<b> for break on this line, C<a> for action on this line, C<:> for this
5141 We save the last line listed in the C<$start> global for further listing
5147 my $current_line = $line;
5151 # If this is '-something', delete any spaces after the dash.
5152 $line =~ s/^-\s*$/-/;
5154 # If the line is '$something', assume this is a scalar containing a
5156 if ( $line =~ /^(\$.*)/s ) {
5158 # Set up for DB::eval() - evaluate in *user* context.
5161 my ($s) = DB::eval();
5163 # Ooops. Bad scalar.
5165 print {$OUT} "Error: $@\n";
5169 # Good scalar. If it's a reference, find what it points to.
5171 print {$OUT} "Interpreted as: $1 $s\n";
5174 # Call self recursively to really do the command.
5176 } ## end if ($line =~ /^(\$.*)/s)
5178 # l name. Try to find a sub by that name.
5179 elsif ( ($subname) = $line =~ /\A([\':A-Za-z_][\':\w]*(?:\[.*\])?)/s ) {
5183 $subname =~ s/\'/::/;
5185 # Put it in this package unless it starts with ::.
5186 $subname = $package . "::" . $subname unless $subname =~ /::/;
5188 # Put it in CORE::GLOBAL if t doesn't start with :: and
5189 # it doesn't live in this package and it lives in CORE::GLOBAL.
5190 $subname = "CORE::GLOBAL::$s"
5191 if not defined &$subname
5193 and defined &{"CORE::GLOBAL::$s"};
5195 # Put leading '::' names into 'main::'.
5196 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
5198 # Get name:start-stop from find_sub, and break this up at
5200 my @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
5202 # Pull off start-stop.
5203 my $subrange = pop @pieces;
5205 # If the name contained colons, the split broke it up.
5206 # Put it back together.
5207 $file = join( ':', @pieces );
5209 # If we're not in that file, switch over to it.
5210 if ( $file ne $filename ) {
5211 print $OUT "Switching to file '$file'.\n"
5212 unless $slave_editor;
5214 # Switch debugger's magic structures.
5215 *dbline = $main::{ '_<' . $file };
5218 } ## end if ($file ne $filename)
5220 # Subrange is 'start-stop'. If this is less than a window full,
5221 # swap it to 'start+', which will list a window from the start point.
5223 if ( eval($subrange) < -$window ) {
5224 $subrange =~ s/-.*/+/;
5227 # Call self recursively to list the range.
5229 cmd_l( 'l', $subrange );
5230 } ## end if ($subrange)
5234 print $OUT "Subroutine $subname not found.\n";
5236 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s)
5239 elsif ( $line !~ /\S/ ) {
5241 # Compute new range to list.
5242 $incr = $window - 1;
5243 $line = $start . '-' . ( $start + $incr );
5246 cmd_l( 'l', $line );
5249 # l [start]+number_of_lines
5250 elsif ( my ($new_start, $new_incr) = $line =~ /\A(\d*)\+(\d*)\z/ ) {
5252 # Don't reset start for 'l +nnn'.
5253 $start = $new_start if $new_start;
5255 # Increment for list. Use window size if not specified.
5256 # (Allows 'l +' to work.)
5258 $incr = $window - 1 unless $incr;
5260 # Create a line range we'll understand, and recurse to do it.
5261 $line = $start . '-' . ( $start + $incr );
5262 cmd_l( 'l', $line );
5263 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/)
5265 # l start-stop or l start,stop
5266 elsif ( $line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/ ) {
5268 # Determine end point; use end of file if not specified.
5269 my $end = ( !defined $2 ) ? $max : ( $4 ? $4 : $2 );
5271 # Go on to the end, and then stop.
5272 $end = $max if $end > $max;
5274 # Determine start line.
5276 $i = $line if $i eq '.';
5280 # If we're running under a slave editor, force it to show the lines.
5281 if ($slave_editor) {
5282 print $OUT "\032\032$filename:$i:0\n";
5286 # We're doing it ourselves. We want to show the line and special
5288 # - the current line in execution
5289 # - whether a line is breakable or not
5290 # - whether a line has a break or not
5291 # - whether a line has an action or not
5293 for ( ; $i <= $end ; $i++ ) {
5295 # Check for breakpoints and actions.
5296 my ( $stop, $action );
5297 ( $stop, $action ) = split( /\0/, $dbline{$i} )
5300 # ==> if this is the current line in execution,
5301 # : if it's breakable.
5303 ( $i == $current_line and $filename eq $filename_ini )
5305 : ( $dbline[$i] + 0 ? ':' : ' ' );
5307 # Add break and action indicators.
5308 $arrow .= 'b' if $stop;
5309 $arrow .= 'a' if $action;
5312 print $OUT "$i$arrow\t", $dbline[$i];
5314 # Move on to the next line. Drop out on an interrupt.
5315 $i++, last if $signal;
5316 } ## end for (; $i <= $end ; $i++)
5318 # Line the prompt up; print a newline if the last line listed
5319 # didn't have a newline.
5320 print $OUT "\n" unless $dbline[ $i - 1 ] =~ /\n$/;
5321 } ## end else [ if ($slave_editor)
5323 # Save the point we last listed to in case another relative 'l'
5324 # command is desired. Don't let it run off the end.
5326 $start = $max if $start > $max;
5327 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/)
5330 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5332 To list breakpoints, the command has to look determine where all of them are
5333 first. It starts a C<%had_breakpoints>, which tells us what all files have
5334 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5335 magic source and breakpoint data structures) to the file, and then look
5336 through C<%dbline> for lines with breakpoints and/or actions, listing them
5337 out. We look through C<%postponed> not-yet-compiled subroutines that have
5338 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5339 that have breakpoints.
5341 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5348 # If no argument, list everything. Pre-5.8.0 version always lists
5350 my $arg = shift || 'abw';
5351 $arg = 'abw' unless $CommandSet eq '580'; # sigh...
5353 # See what is wanted.
5354 my $action_wanted = ( $arg =~ /a/ ) ? 1 : 0;
5355 my $break_wanted = ( $arg =~ /b/ ) ? 1 : 0;
5356 my $watch_wanted = ( $arg =~ /w/ ) ? 1 : 0;
5358 # Breaks and actions are found together, so we look in the same place
5360 if ( $break_wanted or $action_wanted ) {
5362 # Look in all the files with breakpoints...
5363 for my $file ( keys %had_breakpoints ) {
5365 # Temporary switch to this file.
5366 local *dbline = $main::{ '_<' . $file };
5368 # Set up to look through the whole file.
5370 my $was; # Flag: did we print something
5373 # For each line in the file ...
5374 for my $i (1 .. $max) {
5376 # We've got something on this line.
5377 if ( defined $dbline{$i} ) {
5379 # Print the header if we haven't.
5380 print $OUT "$file:\n" unless $was++;
5383 print $OUT " $i:\t", $dbline[$i];
5385 # Pull out the condition and the action.
5386 my ( $stop, $action ) = split( /\0/, $dbline{$i} );
5388 # Print the break if there is one and it's wanted.
5389 print $OUT " break if (", $stop, ")\n"
5393 # Print the action if there is one and it's wanted.
5394 print $OUT " action: ", $action, "\n"
5398 # Quit if the user hit interrupt.
5400 } ## end if (defined $dbline{$i...
5401 } ## end for my $i (1 .. $max)
5402 } ## end for my $file (keys %had_breakpoints)
5403 } ## end if ($break_wanted or $action_wanted)
5405 # Look for breaks in not-yet-compiled subs:
5406 if ( %postponed and $break_wanted ) {
5407 print $OUT "Postponed breakpoints in subroutines:\n";
5409 for $subname ( keys %postponed ) {
5410 print $OUT " $subname\t$postponed{$subname}\n";
5413 } ## end if (%postponed and $break_wanted)
5415 # Find files that have not-yet-loaded breaks:
5416 my @have = map { # Combined keys
5417 keys %{ $postponed_file{$_} }
5418 } keys %postponed_file;
5420 # If there are any, list them.
5421 if ( @have and ( $break_wanted or $action_wanted ) ) {
5422 print $OUT "Postponed breakpoints in files:\n";
5423 for my $file ( keys %postponed_file ) {
5424 my $db = $postponed_file{$file};
5425 print $OUT " $file:\n";
5426 for my $line ( sort { $a <=> $b } keys %$db ) {
5427 print $OUT " $line:\n";
5428 my ( $stop, $action ) = split( /\0/, $$db{$line} );
5429 print $OUT " break if (", $stop, ")\n"
5432 print $OUT " action: ", $action, "\n"
5436 } ## end for $line (sort { $a <=>...
5438 } ## end for $file (keys %postponed_file)
5439 } ## end if (@have and ($break_wanted...
5440 if ( %break_on_load and $break_wanted ) {
5441 print {$OUT} "Breakpoints on load:\n";
5442 BREAK_ON_LOAD: for my $filename ( keys %break_on_load ) {
5443 print {$OUT} " $filename\n";
5444 last BREAK_ON_LOAD if $signal;
5446 } ## end if (%break_on_load and...
5447 if ($watch_wanted and ( $trace & 2 )) {
5448 print {$OUT} "Watch-expressions:\n" if @to_watch;
5449 TO_WATCH: for my $expr (@to_watch) {
5450 print {$OUT} " $expr\n";
5451 last TO_WATCH if $signal;
5456 =head3 C<cmd_M> - list modules (command)
5458 Just call C<list_modules>.
5468 =head3 C<cmd_o> - options (command)
5470 If this is just C<o> by itself, we list the current settings via
5471 C<dump_option>. If there's a nonblank value following it, we pass that on to
5472 C<parse_options> for processing.
5478 my $opt = shift || ''; # opt[=val]
5480 # Nonblank. Try to parse and process.
5481 if ( $opt =~ /^(\S.*)/ ) {
5485 # Blank. List the current option settings.
5493 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5495 Advises the user that the O command has been renamed.
5500 print $OUT "The old O command is now the o command.\n"; # hint
5501 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5502 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5505 =head3 C<cmd_v> - view window (command)
5507 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5508 move back a few lines to list the selected line in context. Uses C<cmd_l>
5509 to do the actual listing after figuring out the range of line to request.
5513 use vars qw($preview);
5519 # Extract the line to list around. (Astute readers will have noted that
5520 # this pattern will match whether or not a numeric line is specified,
5521 # which means that we'll always enter this loop (though a non-numeric
5522 # argument results in no action at all)).
5523 if ( $line =~ /^(\d*)$/ ) {
5525 # Total number of lines to list (a windowful).
5526 $incr = $window - 1;
5528 # Set the start to the argument given (if there was one).
5531 # Back up by the context amount.
5534 # Put together a linespec that cmd_l will like.
5535 $line = $start . '-' . ( $start + $incr );
5538 cmd_l( 'l', $line );
5539 } ## end if ($line =~ /^(\d*)$/)
5542 =head3 C<cmd_w> - add a watch expression (command)
5544 The 5.8 version of this command adds a watch expression if one is specified;
5545 it does nothing if entered with no operands.
5547 We extract the expression, save it, evaluate it in the user's context, and
5548 save the value. We'll re-evaluate it each time the debugger passes a line,
5549 and will stop (see the code at the top of the command loop) if the value
5550 of any of the expressions changes.
5554 sub _add_watch_expr {
5558 push @to_watch, $expr;
5560 # Parameterize DB::eval and call it to get the expression's value
5561 # in the user's context. This version can handle expressions which
5562 # return a list value.
5564 my ($val) = join( ' ', DB::eval() );
5565 $val = ( defined $val ) ? "'$val'" : 'undef';
5567 # Save the current value of the expression.
5568 push @old_watch, $val;
5570 # We are now watching expressions.
5579 # Null expression if no arguments.
5580 my $expr = shift || '';
5582 # If expression is not null ...
5583 if ( $expr =~ /\A\S/ ) {
5584 _add_watch_expr($expr);
5585 } ## end if ($expr =~ /^(\S.*)/)
5587 # You have to give one to get one.
5589 print $OUT "Adding a watch-expression requires an expression\n"; # hint
5595 =head3 C<cmd_W> - delete watch expressions (command)
5597 This command accepts either a watch expression to be removed from the list
5598 of watch expressions, or C<*> to delete them all.
5600 If C<*> is specified, we simply empty the watch expression list and the
5601 watch expression value list. We also turn off the bit that says we've got
5604 If an expression (or partial expression) is specified, we pattern-match
5605 through the expressions and remove the ones that match. We also discard
5606 the corresponding values. If no watch expressions are left, we turn off
5607 the I<watching expressions> bit.
5613 my $expr = shift || '';
5616 if ( $expr eq '*' ) {
5621 print $OUT "Deleting all watch expressions ...\n";
5624 @to_watch = @old_watch = ();
5627 # Delete one of them.
5628 elsif ( $expr =~ /^(\S.*)/ ) {
5630 # Where we are in the list.
5633 # For each expression ...
5634 foreach (@to_watch) {
5635 my $val = $to_watch[$i_cnt];
5637 # Does this one match the command argument?
5638 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
5639 # Yes. Turn it off, and its value too.
5640 splice( @to_watch, $i_cnt, 1 );
5641 splice( @old_watch, $i_cnt, 1 );
5644 } ## end foreach (@to_watch)
5646 # We don't bother to turn watching off because
5647 # a) we don't want to stop calling watchfunction() it it exists
5648 # b) foreach over a null list doesn't do anything anyway
5650 } ## end elsif ($expr =~ /^(\S.*)/)
5652 # No command arguments entered.
5655 "Deleting a watch-expression requires an expression, or '*' for all\n"
5660 ### END of the API section
5662 =head1 SUPPORT ROUTINES
5664 These are general support routines that are used in a number of places
5665 throughout the debugger.
5669 save() saves the user's versions of globals that would mess us up in C<@saved>,
5670 and installs the versions we like better.
5676 # Save eval failure, command failure, extended OS error, output field
5677 # separator, input record separator, output record separator and
5678 # the warning setting.
5679 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
5681 $, = ""; # output field separator is null string
5682 $/ = "\n"; # input record separator is newline
5683 $\ = ""; # output record separator is null string
5684 $^W = 0; # warnings are off
5687 =head2 C<print_lineinfo> - show where we are now
5689 print_lineinfo prints whatever it is that it is handed; it prints it to the
5690 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
5691 us to feed line information to a slave editor without messing up the
5696 sub print_lineinfo {
5698 # Make the terminal sensible if we're not the primary debugger.
5699 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
5703 } ## end sub print_lineinfo
5705 =head2 C<postponed_sub>
5707 Handles setting postponed breakpoints in subroutines once they're compiled.
5708 For breakpoints, we use C<DB::find_sub> to locate the source file and line
5709 range for the subroutine, then mark the file as having a breakpoint,
5710 temporarily switch the C<*dbline> glob over to the source file, and then
5711 search the given range of lines to find a breakable line. If we find one,
5712 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
5716 # The following takes its argument via $evalarg to preserve current @_
5720 # Get the subroutine name.
5721 my $subname = shift;
5723 # If this is a 'break +<n> if <condition>' ...
5724 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
5726 # If there's no offset, use '+0'.
5727 my $offset = $1 || 0;
5729 # find_sub's value is 'fullpath-filename:start-stop'. It's
5730 # possible that the filename might have colons in it too.
5731 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
5734 # We got the start line. Add the offset '+<n>' from
5735 # $postponed{subname}.
5738 # Switch to the file this sub is in, temporarily.
5739 local *dbline = $main::{ '_<' . $file };
5741 # No warnings, please.
5742 local $^W = 0; # != 0 is magical below
5744 # This file's got a breakpoint in it.
5745 $had_breakpoints{$file} |= 1;
5747 # Last line in file.
5750 # Search forward until we hit a breakable line or get to
5751 # the end of the file.
5752 ++$i until $dbline[$i] != 0 or $i >= $max;
5754 # Copy the breakpoint in and delete it from %postponed.
5755 $dbline{$i} = delete $postponed{$subname};
5758 # find_sub didn't find the sub.
5761 print $OUT "Subroutine $subname not found.\n";
5764 } ## end if ($postponed{$subname...
5765 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
5767 #print $OUT "In postponed_sub for '$subname'.\n";
5768 } ## end sub postponed_sub
5772 Called after each required file is compiled, but before it is executed;
5773 also called if the name of a just-compiled subroutine is a key of
5774 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
5775 etc.) into the just-compiled code.
5777 If this is a C<require>'d file, the incoming parameter is the glob
5778 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
5780 If it's a subroutine, the incoming parameter is the subroutine name.
5786 # If there's a break, process it.
5787 if ($ImmediateStop) {
5789 # Right, we've stopped. Turn it off.
5792 # Enter the command loop when DB::DB gets called.
5796 # If this is a subroutine, let postponed_sub() deal with it.
5797 return &postponed_sub unless ref \$_[0] eq 'GLOB';
5799 # Not a subroutine. Deal with the file.
5800 local *dbline = shift;
5801 my $filename = $dbline;
5802 $filename =~ s/^_<//;
5804 $signal = 1, print $OUT "'$filename' loaded...\n"
5805 if $break_on_load{$filename};
5806 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
5808 # Do we have any breakpoints to put in this file?
5809 return unless $postponed_file{$filename};
5811 # Yes. Mark this file as having breakpoints.
5812 $had_breakpoints{$filename} |= 1;
5814 # "Cannot be done: insufficient magic" - we can't just put the
5815 # breakpoints saved in %postponed_file into %dbline by assigning
5816 # the whole hash; we have to do it one item at a time for the
5817 # breakpoints to be set properly.
5818 #%dbline = %{$postponed_file{$filename}};
5820 # Set the breakpoints, one at a time.
5823 for $key ( keys %{ $postponed_file{$filename} } ) {
5825 # Stash the saved breakpoint into the current file's magic line array.
5826 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
5829 # This file's been compiled; discard the stored breakpoints.
5830 delete $postponed_file{$filename};
5832 } ## end sub postponed
5836 C<dumpit> is the debugger's wrapper around dumpvar.pl.
5838 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
5839 a reference to a variable (the thing to be dumped) as its input.
5841 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
5842 the currently-selected filehandle, thank you very much). The current
5843 values of the package globals C<$single> and C<$trace> are backed up in
5844 lexicals, and they are turned off (this keeps the debugger from trying
5845 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
5846 preserve its current value and it is set to zero to prevent entry/exit
5847 messages from printing, and C<$doret> is localized as well and set to -2 to
5848 prevent return values from being shown.
5850 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
5851 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
5852 installed version in C<@INC>, yours will be used instead. Possible security
5855 It then checks to see if the subroutine C<main::dumpValue> is now defined
5856 it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
5857 localizes the globals necessary for things to be sane when C<main::dumpValue()>
5858 is called, and picks up the variable to be dumped from the parameter list.
5860 It checks the package global C<%options> to see if there's a C<dumpDepth>
5861 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
5862 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
5863 structure: -1 means dump everything.
5865 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
5868 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
5869 and we then return to the caller.
5875 # Save the current output filehandle and switch to the one
5876 # passed in as the first parameter.
5877 my $savout = select(shift);
5879 # Save current settings of $single and $trace, and then turn them off.
5880 my $osingle = $single;
5881 my $otrace = $trace;
5882 $single = $trace = 0;
5884 # XXX Okay, what do $frame and $doret do, again?
5888 # Load dumpvar.pl unless we've already got the sub we need from it.
5889 unless ( defined &main::dumpValue ) {
5890 do 'dumpvar.pl' or die $@;
5893 # If the load succeeded (or we already had dumpvalue()), go ahead
5895 if ( defined &main::dumpValue ) {
5900 my $maxdepth = shift || $option{dumpDepth};
5901 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
5902 &main::dumpValue( $v, $maxdepth );
5903 } ## end if (defined &main::dumpValue)
5905 # Oops, couldn't load dumpvar.pl.
5908 print $OUT "dumpvar.pl not available.\n";
5911 # Reset $single and $trace to their old values.
5915 # Restore the old filehandle.
5919 =head2 C<print_trace>
5921 C<print_trace>'s job is to print a stack trace. It does this via the
5922 C<dump_trace> routine, which actually does all the ferreting-out of the
5923 stack trace data. C<print_trace> takes care of formatting it nicely and
5924 printing it to the proper filehandle.
5932 The filehandle to print to.
5936 How many frames to skip before starting trace.
5940 How many frames to print.
5944 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
5948 The original comment below seems to be noting that the traceback may not be
5949 correct if this routine is called in a tied method.
5953 # Tied method do not create a context, so may get wrong message:
5959 # If this is going to a slave editor, but we're not the primary
5960 # debugger, reset it first.
5962 if $fh eq $LINEINFO # slave editor
5963 and $LINEINFO eq $OUT # normal output
5964 and $term_pid != $$; # not the primary
5966 # Collect the actual trace information to be formatted.
5967 # This is an array of hashes of subroutine call info.
5968 my @sub = dump_trace( $_[0] + 1, $_[1] );
5970 # Grab the "short report" flag from @_.
5971 my $short = $_[2]; # Print short report, next one for sub name
5973 # Run through the traceback info, format it, and print it.
5975 for my $i (0 .. $#sub) {
5977 # Drop out if the user has lost interest and hit control-C.
5980 # Set the separator so arrys print nice.
5983 # Grab and stringify the arguments if they are there.
5985 defined $sub[$i]{args}
5986 ? "(@{ $sub[$i]{args} })"
5989 # Shorten them up if $maxtrace says they're too long.
5990 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
5991 if length $args > $maxtrace;
5993 # Get the file name.
5994 my $file = $sub[$i]{file};
5996 # Put in a filename header if short is off.
5997 $file = $file eq '-e' ? $file : "file '$file'" unless $short;
5999 # Get the actual sub's name, and shorten to $maxtrace's requirement.
6001 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
6003 # Short report uses trimmed file and sub names.
6005 my $sub = @_ >= 4 ? $_[3] : $s;
6006 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
6007 } ## end if ($short)
6009 # Non-short report includes full names.
6011 print $fh "$sub[$i]{context} = $s$args"
6012 . " called from $file"
6013 . " line $sub[$i]{line}\n";
6015 } ## end for my $i (0 .. $#sub)
6016 } ## end sub print_trace
6018 =head2 dump_trace(skip[,count])
6020 Actually collect the traceback information available via C<caller()>. It does
6021 some filtering and cleanup of the data, but mostly it just collects it to
6022 make C<print_trace()>'s job easier.
6024 C<skip> defines the number of stack frames to be skipped, working backwards
6025 from the most current. C<count> determines the total number of frames to
6026 be returned; all of them (well, the first 10^9) are returned if C<count>
6029 This routine returns a list of hashes, from most-recent to least-recent
6030 stack frame. Each has the following keys and values:
6034 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
6036 =item * C<sub> - subroutine name, or C<eval> information
6038 =item * C<args> - undef, or a reference to an array of arguments
6040 =item * C<file> - the file in which this item was defined (if any)
6042 =item * C<line> - the line on which it was defined
6050 # How many levels to skip.
6053 # How many levels to show. (1e9 is a cheap way of saying "all of them";
6054 # it's unlikely that we'll have more than a billion stack frames. If you
6055 # do, you've got an awfully big machine...)
6056 my $count = shift || 1e9;
6058 # We increment skip because caller(1) is the first level *back* from
6059 # the current one. Add $skip to the count of frames so we have a
6060 # simple stop criterion, counting from $skip to $count+$skip.
6064 # These variables are used to capture output from caller();
6065 my ( $p, $file, $line, $sub, $h, $context );
6067 my ( $e, $r, @a, @sub, $args );
6069 # XXX Okay... why'd we do that?
6070 my $nothard = not $frame & 8;
6073 # Do not want to trace this.
6074 my $otrace = $trace;
6077 # Start out at the skip count.
6078 # If we haven't reached the number of frames requested, and caller() is
6079 # still returning something, stay in the loop. (If we pass the requested
6080 # number of stack frames, or we run out - caller() returns nothing - we
6082 # Up the stack frame index to go back one more level each time.
6086 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
6091 # Go through the arguments and save them for later.
6093 for my $arg (@args) {
6095 if ( not defined $arg ) { # undefined parameter
6099 elsif ( $nothard and tied $arg ) { # tied parameter
6102 elsif ( $nothard and $type = ref $arg ) { # reference
6103 push @a, "ref($type)";
6105 else { # can be stringified
6107 "$arg"; # Safe to stringify now - should not call f().
6109 # Backslash any single-quotes or backslashes.
6112 # Single-quote it unless it's a number or a colon-separated
6115 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
6117 # Turn high-bit characters into meta-whatever.
6118 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
6120 # Turn control characters into ^-whatever.
6121 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
6124 } ## end else [ if (not defined $arg)
6125 } ## end for $arg (@args)
6127 # If context is true, this is array (@)context.
6128 # If context is false, this is scalar ($) context.
6129 # If neither, context isn't defined. (This is apparently a 'can't
6131 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
6133 # if the sub has args ($h true), make an anonymous array of the
6135 $args = $h ? [@a] : undef;
6137 # remove trailing newline-whitespace-semicolon-end of line sequence
6138 # from the eval text, if any.
6139 $e =~ s/\n\s*\;\s*\Z// if $e;
6141 # Escape backslashed single-quotes again if necessary.
6142 $e =~ s/([\\\'])/\\$1/g if $e;
6144 # if the require flag is true, the eval text is from a require.
6146 $sub = "require '$e'";
6149 # if it's false, the eval text is really from an eval.
6150 elsif ( defined $r ) {
6154 # If the sub is '(eval)', this is a block eval, meaning we don't
6155 # know what the eval'ed text actually was.
6156 elsif ( $sub eq '(eval)' ) {
6157 $sub = "eval {...}";
6160 # Stick the collected information into @sub as an anonymous hash.
6164 context => $context,
6172 # Stop processing frames if the user hit control-C.
6174 } ## end for ($i = $skip ; $i < ...
6176 # Restore the trace value again.
6179 } ## end sub dump_trace
6183 C<action()> takes input provided as the argument to an add-action command,
6184 either pre- or post-, and makes sure it's a complete command. It doesn't do
6185 any fancy parsing; it just keeps reading input until it gets a string
6186 without a trailing backslash.
6193 while ( $action =~ s/\\$// ) {
6195 # We have a backslash on the end. Read more.
6197 } ## end while ($action =~ s/\\$//)
6199 # Return the assembled action.
6205 This routine mostly just packages up a regular expression to be used
6206 to check that the thing it's being matched against has properly-matched
6209 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
6210 speeds things up by only creating the qr//'ed expression once; if it's
6211 already defined, we don't try to define it again. A speed hack.
6215 use vars qw($balanced_brace_re);
6219 # I hate using globals!
6220 $balanced_brace_re ||= qr{
6223 (?> [^{}] + ) # Non-parens without backtracking
6225 (??{ $balanced_brace_re }) # Group with matching parens
6229 return $_[0] !~ m/$balanced_brace_re/;
6230 } ## end sub unbalanced
6234 C<gets()> is a primitive (very primitive) routine to read continuations.
6235 It was devised for reading continuations for actions.
6236 it just reads more input with C<readline()> and returns it.
6241 &readline("cont: ");
6244 =head2 C<DB::system()> - handle calls to<system()> without messing up the debugger
6246 The C<system()> function assumes that it can just go ahead and use STDIN and
6247 STDOUT, but under the debugger, we want it to use the debugger's input and
6250 C<DB::system()> socks away the program's STDIN and STDOUT, and then substitutes
6251 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
6252 and then puts everything back again.
6258 # We save, change, then restore STDIN and STDOUT to avoid fork() since
6259 # some non-Unix systems can do system() but have problems with fork().
6260 open( SAVEIN, "<&STDIN" ) || &warn("Can't save STDIN");
6261 open( SAVEOUT, ">&STDOUT" ) || &warn("Can't save STDOUT");
6262 open( STDIN, "<&IN" ) || &warn("Can't redirect STDIN");
6263 open( STDOUT, ">&OUT" ) || &warn("Can't redirect STDOUT");
6265 # XXX: using csh or tcsh destroys sigint retvals!
6267 open( STDIN, "<&SAVEIN" ) || &warn("Can't restore STDIN");
6268 open( STDOUT, ">&SAVEOUT" ) || &warn("Can't restore STDOUT");
6272 # most of the $? crud was coping with broken cshisms
6274 &warn( "(Command exited ", ( $? >> 8 ), ")\n" );
6278 "(Command died of SIG#",
6280 ( ( $? & 128 ) ? " -- core dumped" : "" ),
6289 =head1 TTY MANAGEMENT
6291 The subs here do some of the terminal management for multiple debuggers.
6295 Top-level function called when we want to set up a new terminal for use
6298 If the C<noTTY> debugger option was set, we'll either use the terminal
6299 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
6300 to find one. If we're a forked debugger, we call C<resetterm> to try to
6301 get a whole new terminal if we can.
6303 In either case, we set up the terminal next. If the C<ReadLine> option was
6304 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6305 the appropriate attributes. We then
6309 use vars qw($ornaments);
6310 use vars qw($rl_attribs);
6314 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6317 require Term::ReadLine;
6319 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6322 my ( $i, $o ) = split $tty, /,/;
6323 $o = $i unless defined $o;
6324 open( IN, "<$i" ) or die "Cannot open TTY '$i' for read: $!";
6325 open( OUT, ">$o" ) or die "Cannot open TTY '$o' for write: $!";
6331 # We don't have a TTY - try to find one via Term::Rendezvous.
6333 require Term::Rendezvous;
6335 # See if we have anything to pass to Term::Rendezvous.
6336 # Use $HOME/.perldbtty$$ if not.
6337 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6339 # Rendezvous and get the filehandles.
6340 my $term_rv = Term::Rendezvous->new( $rv );
6342 $OUT = $term_rv->OUT;
6343 } ## end else [ if ($tty)
6344 } ## end if ($notty)
6346 # We're a daughter debugger. Try to fork off another TTY.
6347 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6351 # If we shouldn't use Term::ReadLine, don't.
6353 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6356 # We're using Term::ReadLine. Get all the attributes for this terminal.
6358 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6360 $rl_attribs = $term->Attribs;
6361 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6362 if defined $rl_attribs->{basic_word_break_characters}
6363 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6364 $rl_attribs->{special_prefixes} = '$@&%';
6365 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6366 $rl_attribs->{completion_function} = \&db_complete;
6367 } ## end else [ if (!$rl)
6369 # Set up the LINEINFO filehandle.
6370 $LINEINFO = $OUT unless defined $LINEINFO;
6371 $lineinfo = $console unless defined $lineinfo;
6377 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6378 $term->SetHistory(@hist);
6381 # XXX Ornaments are turned on unconditionally, which is not
6382 # always a good thing.
6383 ornaments($ornaments) if defined $ornaments;
6385 } ## end sub setterm
6388 $histfile //= option_val("HistFile", undef);
6389 return unless defined $histfile;
6390 open my $fh, "<", $histfile or return;
6401 return unless defined $histfile;
6402 eval { require File::Path } or return;
6403 eval { require File::Basename } or return;
6404 File::Path::mkpath(File::Basename::dirname($histfile));
6405 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6406 $histsize //= option_val("HistSize",100);
6407 my @copy = grep { $_ ne '?' } @hist;
6408 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6409 for ($start .. $#copy) {
6410 print $fh "$copy[$_]\n";
6412 close $fh or die "Could not write '$histfile': $!";
6415 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6417 When the process being debugged forks, or the process invokes a command
6418 via C<system()> which starts a new debugger, we need to be able to get a new
6419 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6420 fight over the terminal, and you can never quite be sure who's going to get the
6421 input you're typing.
6423 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6424 is tasked with doing all the necessary operating system mojo to get a new
6425 TTY (and probably another window) and to direct the new debugger to read and
6428 The debugger provides C<get_fork_TTY> functions which work for TCP
6429 socket servers, X11, OS/2, and Mac OS X. Other systems are not
6430 supported. You are encouraged to write C<get_fork_TTY> functions which
6431 work for I<your> platform and contribute them.
6433 =head3 C<socket_get_fork_TTY>
6437 sub connect_remoteport {
6440 my $socket = IO::Socket::INET->new(
6442 PeerAddr => $remoteport,
6446 die "Unable to connect to remote host: $remoteport\n";
6451 sub socket_get_fork_TTY {
6452 $tty = $LINEINFO = $IN = $OUT = connect_remoteport();
6454 # Do I need to worry about setting $term?
6456 reset_IN_OUT( $IN, $OUT );
6460 =head3 C<xterm_get_fork_TTY>
6462 This function provides the C<get_fork_TTY> function for X11. If a
6463 program running under the debugger forks, a new <xterm> window is opened and
6464 the subsidiary debugger is directed there.
6466 The C<open()> call is of particular note here. We have the new C<xterm>
6467 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6468 command (which prints the device name of the TTY we'll want to use for input
6469 and output to STDOUT, then C<sleep> for a very long time, routing this output
6470 to file number 3. This way we can simply read from the <XT> filehandle (which
6471 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6473 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6478 sub xterm_get_fork_TTY {
6479 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6481 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6484 # Get the output from 'tty' and clean it up a little.
6488 $pidprompt = ''; # Shown anyway in titlebar
6490 # We need $term defined or we can not switch to the newly created xterm
6491 if ($tty ne '' && !defined $term) {
6492 require Term::ReadLine;
6494 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6497 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6500 # There's our new TTY.
6502 } ## end sub xterm_get_fork_TTY
6504 =head3 C<os2_get_fork_TTY>
6506 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6510 # This example function resets $IN, $OUT itself
6512 sub os2_get_fork_TTY { # A simplification of the following (and works without):
6514 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6515 my %opt = ( title => "Daughter Perl debugger $pids $name",
6516 ($rl ? (read_by_key => 1) : ()) );
6517 require OS2::Process;
6518 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
6520 $pidprompt = ''; # Shown anyway in titlebar
6521 reset_IN_OUT($in, $out);
6523 return ''; # Indicate that reset_IN_OUT is called
6524 } ## end sub os2_get_fork_TTY
6526 =head3 C<macosx_get_fork_TTY>
6528 The Mac OS X version uses AppleScript to tell Terminal.app to create
6533 # Notes about Terminal.app's AppleScript support,
6534 # (aka things that might break in future OS versions).
6536 # The "do script" command doesn't return a reference to the new window
6537 # it creates, but since it appears frontmost and windows are enumerated
6538 # front to back, we can use "first window" === "window 1".
6540 # Since "do script" is implemented by supplying the argument (plus a
6541 # return character) as terminal input, there's a potential race condition
6542 # where the debugger could beat the shell to reading the command.
6543 # To prevent this, we wait for the screen to clear before proceeding.
6546 # There's no direct accessor for the tty device name, so we fiddle
6547 # with the window title options until it says what we want.
6550 # There _is_ a direct accessor for the tty device name, _and_ there's
6551 # a new possible component of the window title (the name of the settings
6552 # set). A separate version is needed.
6554 my @script_versions=
6556 ([237, <<'__LEOPARD__'],
6557 tell application "Terminal"
6558 do script "clear;exec sleep 100000"
6559 tell first tab of first window
6561 set custom title to "forked perl debugger"
6562 set title displays custom title to true
6563 repeat while (length of first paragraph of (get contents)) > 0
6571 [100, <<'__JAGUAR_TIGER__'],
6572 tell application "Terminal"
6573 do script "clear;exec sleep 100000"
6575 set title displays shell path to false
6576 set title displays window size to false
6577 set title displays file name to false
6578 set title displays device name to true
6579 set title displays custom title to true
6580 set custom title to ""
6581 copy "/dev/" & name to thetty
6582 set custom title to "forked perl debugger"
6583 repeat while (length of first paragraph of (get contents)) > 0
6593 sub macosx_get_fork_TTY
6595 my($version,$script,$pipe,$tty);
6597 return unless $version=$ENV{TERM_PROGRAM_VERSION};
6598 foreach my $entry (@script_versions) {
6599 if ($version>=$entry->[0]) {
6600 $script=$entry->[1];
6604 return unless defined($script);
6605 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script);
6606 $tty=readline($pipe);
6608 return unless defined($tty) && $tty =~ m(^/dev/);
6613 =head2 C<create_IN_OUT($flags)>
6615 Create a new pair of filehandles, pointing to a new TTY. If impossible,
6616 try to diagnose why.
6622 =item * 1 - Don't know how to create a new TTY.
6624 =item * 2 - Debugger has forked, but we can't get a new TTY.
6626 =item * 4 - standard debugger startup is happening.
6632 use vars qw($fork_TTY);
6634 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
6636 # If we know how to get a new TTY, do it! $in will have
6637 # the TTY name if get_fork_TTY works.
6638 my $in = &get_fork_TTY if defined &get_fork_TTY;
6640 # It used to be that
6641 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
6643 if ( not defined $in ) {
6646 # We don't know how.
6647 print_help(<<EOP) if $why == 1;
6648 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
6652 print_help(<<EOP) if $why == 2;
6653 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
6654 This may be an asynchronous session, so the parent debugger may be active.
6657 # Note that both debuggers are fighting over the same input.
6658 print_help(<<EOP) if $why != 4;
6659 Since two debuggers fight for the same TTY, input is severely entangled.
6663 I know how to switch the output to a different window in xterms, OS/2
6664 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
6665 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
6666 B<DB::get_fork_TTY()> returning this.
6668 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
6669 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
6672 } ## end if (not defined $in)
6673 elsif ( $in ne '' ) {
6677 $console = ''; # Indicate no need to open-from-the-console
6680 } ## end sub create_IN_OUT
6684 Handles rejiggering the prompt when we've forked off a new debugger.
6686 If the new debugger happened because of a C<system()> that invoked a
6687 program under the debugger, the arrow between the old pid and the new
6688 in the prompt has I<two> dashes instead of one.
6690 We take the current list of pids and add this one to the end. If there
6691 isn't any list yet, we make one up out of the initial pid associated with
6692 the terminal and our new pid, sticking an arrow (either one-dashed or
6693 two dashed) in between them.
6695 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
6696 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
6701 sub resetterm { # We forked, so we need a different TTY
6703 # Needs to be passed to create_IN_OUT() as well.
6706 # resetterm(2): got in here because of a system() starting a debugger.
6707 # resetterm(1): just forked.
6708 my $systemed = $in > 1 ? '-' : '';
6710 # If there's already a list of pids, add this to the end.
6712 $pids =~ s/\]/$systemed->$$]/;
6715 # No pid list. Time to make one.
6717 $pids = "[$term_pid->$$]";
6720 # The prompt we're going to be using for this debugger.
6723 # We now 0wnz this terminal.
6726 # Just return if we're not supposed to try to create a new TTY.
6727 return unless $CreateTTY & $in;
6729 # Try to create a new IN/OUT pair.
6731 } ## end sub resetterm
6735 First, we handle stuff in the typeahead buffer. If there is any, we shift off
6736 the next line, print a message saying we got it, add it to the terminal
6737 history (if possible), and return it.
6739 If there's nothing in the typeahead buffer, check the command filehandle stack.
6740 If there are any filehandles there, read from the last one, and return the line
6741 if we got one. If not, we pop the filehandle off and close it, and try the
6742 next one up the stack.
6744 If we've emptied the filehandle stack, we check to see if we've got a socket
6745 open, and we read that and return it if we do. If we don't, we just call the
6746 core C<readline()> and return its value.
6752 # Localize to prevent it from being smashed in the program being debugged.
6755 # If there are stacked filehandles to read from ...
6756 # (Handle it before the typeahead, because we may call source/etc. from
6760 # Read from the last one in the stack.
6761 my $line = CORE::readline( $cmdfhs[-1] );
6763 # If we got a line ...
6765 ? ( print $OUT ">> $line" and return $line ) # Echo and return
6766 : close pop @cmdfhs; # Pop and close
6767 } ## end while (@cmdfhs)
6769 # Pull a line out of the typeahead if there's stuff there.
6772 # How many lines left.
6773 my $left = @typeahead;
6775 # Get the next line.
6776 my $got = shift @typeahead;
6778 # Print a message saying we got input from the typeahead.
6780 print $OUT "auto(-$left)", shift, $got, "\n";
6782 # Add it to the terminal history (if possible).
6783 $term->AddHistory($got)
6785 and defined $term->Features->{addHistory};
6787 } ## end if (@typeahead)
6789 # We really need to read some input. Turn off entry/exit trace and
6790 # return value printing.
6794 # Nothing on the filehandle stack. Socket?
6795 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
6797 # Send anything we have to send.
6798 $OUT->write( join( '', @_ ) );
6800 # Receive anything there is to receive.
6805 while ($first_time or (length($buf) && ($stuff .= $buf) !~ /\n/))
6808 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
6809 # XXX Don't know. You tell me.
6814 } ## end if (ref $OUT and UNIVERSAL::isa...
6816 # No socket. Just read from the terminal.
6818 return $term->readline(@_);
6820 } ## end sub readline
6822 =head1 OPTIONS SUPPORT ROUTINES
6824 These routines handle listing and setting option values.
6826 =head2 C<dump_option> - list the current value of an option setting
6828 This routine uses C<option_val> to look up the value for an option.
6829 It cleans up escaped single-quotes and then displays the option and
6835 my ( $opt, $val ) = @_;
6836 $val = option_val( $opt, 'N/A' );
6837 $val =~ s/([\\\'])/\\$1/g;
6838 printf $OUT "%20s = '%s'\n", $opt, $val;
6839 } ## end sub dump_option
6841 sub options2remember {
6842 foreach my $k (@RememberOnROptions) {
6843 $option{$k} = option_val( $k, 'N/A' );
6848 =head2 C<option_val> - find the current value of an option
6850 This can't just be a simple hash lookup because of the indirect way that
6851 the option values are stored. Some are retrieved by calling a subroutine,
6852 some are just variables.
6854 You must supply a default value to be used in case the option isn't set.
6859 my ( $opt, $default ) = @_;
6862 # Does this option exist, and is it a variable?
6863 # If so, retrieve the value via the value in %optionVars.
6864 if ( defined $optionVars{$opt}
6865 and defined ${ $optionVars{$opt} } )
6867 $val = ${ $optionVars{$opt} };
6870 # Does this option exist, and it's a subroutine?
6871 # If so, call the subroutine via the ref in %optionAction
6872 # and capture the value.
6873 elsif ( defined $optionAction{$opt}
6874 and defined &{ $optionAction{$opt} } )
6876 $val = &{ $optionAction{$opt} }();
6879 # If there's an action or variable for the supplied option,
6880 # but no value was set, use the default.
6881 elsif (defined $optionAction{$opt} and not defined $option{$opt}
6882 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
6887 # Otherwise, do the simple hash lookup.
6889 $val = $option{$opt};
6892 # If the value isn't defined, use the default.
6893 # Then return whatever the value is.
6894 $val = $default unless defined $val;
6896 } ## end sub option_val
6898 =head2 C<parse_options>
6900 Handles the parsing and execution of option setting/displaying commands.
6902 An option entered by itself is assumed to be I<set me to 1> (the default value)
6903 if the option is a boolean one. If not, the user is prompted to enter a valid
6904 value or to query the current value (via C<option? >).
6906 If C<option=value> is entered, we try to extract a quoted string from the
6907 value (if it is quoted). If it's not, we just use the whole value as-is.
6909 We load any modules required to service this option, and then we set it: if
6910 it just gets stuck in a variable, we do that; if there's a subroutine to
6911 handle setting the option, we call that.
6913 Finally, if we're running in interactive mode, we display the effect of the
6914 user's command back to the terminal, skipping this if we're setting things
6915 during initialization.
6925 # These options need a value. Don't allow them to be clobbered by accident.
6926 my %opt_needs_val = map { ( $_ => 1 ) } qw{
6927 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
6928 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
6931 while (length($s)) {
6934 # Clean off excess leading whitespace.
6935 $s =~ s/^\s+// && next;
6937 # Options are always all word characters, followed by a non-word
6939 if ($s !~ s/^(\w+)(\W?)//) {
6940 print {$OUT} "Invalid option '$s'\n";
6943 my ( $opt, $sep ) = ( $1, $2 );
6945 # Make sure that such an option exists.
6946 my $matches = ( grep { /^\Q$opt/ && ( $option = $_ ) } @options )
6947 || ( grep { /^\Q$opt/i && ( $option = $_ ) } @options );
6950 print {$OUT} "Unknown option '$opt'\n";
6954 print {$OUT} "Ambiguous option '$opt'\n";
6959 # '?' as separator means query, but must have whitespace after it.
6960 if ( "?" eq $sep ) {
6962 print {$OUT} "Option query '$opt?' followed by non-space '$s'\n" ;
6967 #&dump_option($opt);
6968 } ## end if ("?" eq $sep)
6970 # Separator is whitespace (or just a carriage return).
6971 # They're going for a default, which we assume is 1.
6972 elsif ( $sep !~ /\S/ ) {
6974 $val = "1"; # this is an evil default; make 'em set it!
6977 # Separator is =. Trying to set a value.
6978 elsif ( $sep eq "=" ) {
6980 # If quoted, extract a quoted string.
6981 if ($s =~ s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
6983 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
6986 # Not quoted. Use the whole thing. Warn about 'option='.
6990 print OUT qq(Option better cleared using $opt=""\n)
6992 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
6994 } ## end elsif ($sep eq "=")
6996 # "Quoted" with [], <>, or {}.
6997 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
6999 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
7000 $s =~ s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
7001 or print( $OUT "Unclosed option value '$opt$sep$_'\n" ), last;
7002 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
7003 } ## end else [ if ("?" eq $sep)
7005 # Exclude non-booleans from getting set to 1 by default.
7006 if ( $opt_needs_val{$option} && $val_defaulted ) {
7007 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
7009 "Option '$opt' is non-boolean. Use '$cmd $option=VAL' to set, '$cmd $option?' to query\n";
7011 } ## end if ($opt_needs_val{$option...
7013 # Save the option value.
7014 $option{$option} = $val if defined $val;
7016 # Load any module that this option requires.
7017 if ( defined($optionRequire{$option}) && defined($val) ) {
7021 require '$optionRequire{$option}';
7023 } || die $@ # XXX: shouldn't happen
7027 # Stick it in the proper variable if it goes in a variable.
7028 if (defined($optionVars{$option}) && defined($val)) {
7029 ${ $optionVars{$option} } = $val;
7032 # Call the appropriate sub if it gets set via sub.
7033 if (defined($optionAction{$option})
7034 && defined (&{ $optionAction{$option} })
7037 &{ $optionAction{$option} }($val);
7040 # Not initialization - echo the value we set it to.
7041 dump_option($option) if ($OUT ne \*STDERR);
7042 } ## end while (length)
7043 } ## end sub parse_options
7045 =head1 RESTART SUPPORT
7047 These routines are used to store (and restore) lists of items in environment
7048 variables during a restart.
7052 Set_list packages up items to be stored in a set of environment variables
7053 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
7054 the values). Values outside the standard ASCII charset are stored by encoding
7055 then as hexadecimal values.
7060 my ( $stem, @list ) = @_;
7063 # VAR_n: how many we have. Scalar assignment gets the number of items.
7064 $ENV{"${stem}_n"} = @list;
7066 # Grab each item in the list, escape the backslashes, encode the non-ASCII
7067 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
7068 for my $i ( 0 .. $#list ) {
7070 $val =~ s/\\/\\\\/g;
7071 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
7072 $ENV{"${stem}_$i"} = $val;
7073 } ## end for $i (0 .. $#list)
7074 } ## end sub set_list
7078 Reverse the set_list operation: grab VAR_n to see how many we should be getting
7079 back, and then pull VAR_0, VAR_1. etc. back out.
7086 my $n = delete $ENV{"${stem}_n"};
7088 for my $i ( 0 .. $n - 1 ) {
7089 $val = delete $ENV{"${stem}_$i"};
7090 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
7094 } ## end sub get_list
7096 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
7100 The C<catch()> subroutine is the essence of fast and low-impact. We simply
7101 set an already-existing global scalar variable to a constant value. This
7102 avoids allocating any memory possibly in the middle of something that will
7103 get all confused if we do, particularly under I<unsafe signals>.
7109 return; # Put nothing on the stack - malloc/free land!
7114 C<warn> emits a warning, by joining together its arguments and printing
7115 them, with couple of fillips.
7117 If the composited message I<doesn't> end with a newline, we automatically
7118 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
7119 to be set to the filehandle to be used to output warnings; it makes no
7120 assumptions about what filehandles are available.
7125 my ($msg) = join( "", @_ );
7126 $msg .= ": $!\n" unless $msg =~ /\n$/;
7131 =head1 INITIALIZATION TTY SUPPORT
7133 =head2 C<reset_IN_OUT>
7135 This routine handles restoring the debugger's input and output filehandles
7136 after we've tried and failed to move them elsewhere. In addition, it assigns
7137 the debugger's output filehandle to $LINEINFO if it was already open there.
7142 my $switch_li = $LINEINFO eq $OUT;
7144 # If there's a term and it's able to get a new tty, try to get one.
7145 if ( $term and $term->Features->{newTTY} ) {
7146 ( $IN, $OUT ) = ( shift, shift );
7147 $term->newTTY( $IN, $OUT );
7150 # This term can't get a new tty now. Better luck later.
7152 &warn("Too late to set IN/OUT filehandles, enabled on next 'R'!\n");
7155 # Set the filehndles up as they were.
7157 ( $IN, $OUT ) = ( shift, shift );
7160 # Unbuffer the output filehandle.
7163 # Point LINEINFO to the same output filehandle if it was there before.
7164 $LINEINFO = $OUT if $switch_li;
7165 } ## end sub reset_IN_OUT
7167 =head1 OPTION SUPPORT ROUTINES
7169 The following routines are used to process some of the more complicated
7174 Sets the input and output filehandles to the specified files or pipes.
7175 If the terminal supports switching, we go ahead and do it. If not, and
7176 there's already a terminal in place, we save the information to take effect
7179 If there's no terminal yet (for instance, during debugger initialization),
7180 we go ahead and set C<$console> and C<$tty> to the file indicated.
7186 if ( @_ and $term and $term->Features->{newTTY} ) {
7188 # This terminal supports switching to a new TTY.
7189 # Can be a list of two files, or on string containing both names,
7191 # XXX Should this perhaps be an assignment from @_?
7192 my ( $in, $out ) = shift;
7195 # Split list apart if supplied.
7196 ( $in, $out ) = split /,/, $in, 2;
7200 # Use the same file for both input and output.
7204 # Open file onto the debugger's filehandles, if you can.
7205 open IN, $in or die "cannot open '$in' for read: $!";
7206 open OUT, ">$out" or die "cannot open '$out' for write: $!";
7208 # Swap to the new filehandles.
7209 reset_IN_OUT( \*IN, \*OUT );
7211 # Save the setting for later.
7213 } ## end if (@_ and $term and $term...
7215 # Terminal doesn't support new TTY, or doesn't support readline.
7216 # Can't do it now, try restarting.
7217 &warn("Too late to set TTY, enabled on next 'R'!\n") if $term and @_;
7219 # Useful if done through PERLDB_OPTS:
7220 $console = $tty = shift if @_;
7222 # Return whatever the TTY is.
7228 Sets the C<$notty> global, controlling whether or not the debugger tries to
7229 get a terminal to read from. If called after a terminal is already in place,
7230 we save the value to use it if we're restarted.
7236 &warn("Too late to set noTTY, enabled on next 'R'!\n") if @_;
7238 $notty = shift if @_;
7244 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
7245 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
7246 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
7247 the value in case a restart is done so we can change it then.
7253 &warn("Too late to set ReadLine, enabled on next 'R'!\n") if @_;
7257 } ## end sub ReadLine
7259 =head2 C<RemotePort>
7261 Sets the port that the debugger will try to connect to when starting up.
7262 If the terminal's already been set up, we can't do it, but we remember the
7263 setting in case the user does a restart.
7269 &warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
7271 $remoteport = shift if @_;
7273 } ## end sub RemotePort
7277 Checks with the terminal to see if C<Tk> is running, and returns true or
7278 false. Returns false if the current terminal doesn't support C<readline>.
7283 if ( ${ $term->Features }{tkRunning} ) {
7284 return $term->tkRunning(@_);
7288 print $OUT "tkRunning not supported by current ReadLine package.\n";
7291 } ## end sub tkRunning
7295 Sets nonstop mode. If a terminal's already been set up, it's too late; the
7296 debugger remembers the setting in case you restart, though.
7302 &warn("Too late to set up NonStop mode, enabled on next 'R'!\n")
7305 $runnonstop = shift if @_;
7307 } ## end sub NonStop
7311 &warn("Some flag changes could not take effect until next 'R'!\n")
7314 $^P = parse_DollarCaretP_flags(shift) if @_;
7315 expand_DollarCaretP_flags($^P);
7320 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
7328 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
7335 Sets the shell escape command, and generates a printable copy to be used
7342 # If we got an argument, meta-quote it, and add '\b' if it
7343 # ends in a word character.
7345 $sh = quotemeta shift;
7346 $sh .= "\\b" if $sh =~ /\w$/;
7349 # Generate the printable version for the help:
7350 $psh = $sh; # copy it
7351 $psh =~ s/\\b$//; # Take off trailing \b if any
7352 $psh =~ s/\\(.)/$1/g; # De-escape
7353 $psh; # return the printable version
7354 } ## end sub shellBang
7358 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7359 was passed as the argument. (This means you can't override the terminal's
7365 if ( defined $term ) {
7367 # We don't want to show warning backtraces, but we do want die() ones.
7368 local ( $warnLevel, $dieLevel ) = ( 0, 1 );
7370 # No ornaments if the terminal doesn't support them.
7371 return '' unless $term->Features->{ornaments};
7372 eval { $term->ornaments(@_) } || '';
7375 # Use what was passed in if we can't determine it ourselves.
7379 } ## end sub ornaments
7381 =head2 C<recallCommand>
7383 Sets the recall command, and builds a printable version which will appear in
7390 # If there is input, metaquote it. Add '\b' if it ends with a word
7393 $rc = quotemeta shift;
7394 $rc .= "\\b" if $rc =~ /\w$/;
7397 # Build it into a printable version.
7398 $prc = $rc; # Copy it
7399 $prc =~ s/\\b$//; # Remove trailing \b
7400 $prc =~ s/\\(.)/$1/g; # Remove escapes
7401 $prc; # Return the printable version
7402 } ## end sub recallCommand
7404 =head2 C<LineInfo> - where the line number information goes
7406 Called with no arguments, returns the file or pipe that line info should go to.
7408 Called with an argument (a file or a pipe), it opens that onto the
7409 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7410 file or pipe again to the caller.
7418 # If this is a valid "thing to be opened for output", tack a
7419 # '>' onto the front.
7420 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7422 # If this is a pipe, the stream points to a slave editor.
7423 $slave_editor = ( $stream =~ /^\|/ );
7425 # Open it up and unbuffer it.
7426 open( LINEINFO, $stream ) || &warn("Cannot open '$stream' for write");
7427 $LINEINFO = \*LINEINFO;
7428 $LINEINFO->autoflush(1);
7432 } ## end sub LineInfo
7434 =head1 COMMAND SUPPORT ROUTINES
7436 These subroutines provide functionality for various commands.
7438 =head2 C<list_modules>
7440 For the C<M> command: list modules loaded and their versions.
7441 Essentially just runs through the keys in %INC, picks each package's
7442 C<$VERSION> variable, gets the file name, and formats the information
7447 sub list_modules { # versions
7451 # keys are the "as-loaded" name, values are the fully-qualified path
7452 # to the file itself.
7454 $file = $_; # get the module name
7455 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
7456 s,/,::,g; # change '/' to '::'
7457 s/^perl5db$/DB/; # Special case: debugger
7458 # moves to package DB
7459 s/^Term::ReadLine::readline$/readline/; # simplify readline
7461 # If the package has a $VERSION package global (as all good packages
7462 # should!) decode it and save as partial message.
7463 my $pkg_version = do { no strict 'refs'; ${ $_ . '::VERSION' } };
7464 if ( defined $pkg_version ) {
7465 $version{$file} = "$pkg_version from ";
7468 # Finish up the message with the file the package came from.
7469 $version{$file} .= $INC{$file};
7470 } ## end for (keys %INC)
7472 # Hey, dumpit() formats a hash nicely, so why not use it?
7473 dumpit( $OUT, \%version );
7474 } ## end sub list_modules
7478 Sets up the monster string used to format and print the help.
7480 =head3 HELP MESSAGE FORMAT
7482 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
7483 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
7484 easy to parse and portable, but which still allows the help to be a little
7485 nicer than just plain text.
7487 Essentially, you define the command name (usually marked up with C<< B<> >>
7488 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
7489 newline. The descriptive text can also be marked up in the same way. If you
7490 need to continue the descriptive text to another line, start that line with
7491 just tabs and then enter the marked-up text.
7493 If you are modifying the help text, I<be careful>. The help-string parser is
7494 not very sophisticated, and if you don't follow these rules it will mangle the
7495 help beyond hope until you fix the string.
7499 use vars qw($pre580_help);
7500 use vars qw($pre580_summary);
7504 # XXX: make sure there are tabs between the command and explanation,
7505 # or print_help will screw up your formatting if you have
7506 # eeevil ornaments enabled. This is an insane mess.
7509 Help is currently only available for the new 5.8 command set.
7510 No help is available for the old command set.
7511 We assume you know what you're doing if you switch to it.
7514 B<s> [I<expr>] Single step [in I<expr>].
7515 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7516 <B<CR>> Repeat last B<n> or B<s> command.
7517 B<r> Return from current subroutine.
7518 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7519 at the specified position.
7520 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7521 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7522 B<l> I<line> List single I<line>.
7523 B<l> I<subname> List first window of lines from subroutine.
7524 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7525 B<l> List next window of lines.
7526 B<-> List previous window of lines.
7527 B<v> [I<line>] View window around I<line>.
7528 B<.> Return to the executed line.
7529 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7530 I<filename> may be either the full name of the file, or a regular
7531 expression matching the full file name:
7532 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7533 Evals (with saved bodies) are considered to be filenames:
7534 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7535 (in the order of execution).
7536 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7537 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7538 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
7539 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7540 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth).
7541 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
7542 B<b> Sets breakpoint on current line)
7543 B<b> [I<line>] [I<condition>]
7544 Set breakpoint; I<line> defaults to the current execution line;
7545 I<condition> breaks if it evaluates to true, defaults to '1'.
7546 B<b> I<subname> [I<condition>]
7547 Set breakpoint at first line of subroutine.
7548 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7549 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7550 B<b> B<postpone> I<subname> [I<condition>]
7551 Set breakpoint at first line of subroutine after
7553 B<b> B<compile> I<subname>
7554 Stop after the subroutine is compiled.
7555 B<B> [I<line>] Delete the breakpoint for I<line>.
7556 B<B> I<*> Delete all breakpoints.
7557 B<a> [I<line>] I<command>
7558 Set an action to be done before the I<line> is executed;
7559 I<line> defaults to the current execution line.
7560 Sequence is: check for breakpoint/watchpoint, print line
7561 if necessary, do action, prompt user if necessary,
7564 B<A> [I<line>] Delete the action for I<line>.
7565 B<A> I<*> Delete all actions.
7566 B<w> I<expr> Add a global watch-expression.
7568 B<W> I<expr> Delete a global watch-expression.
7569 B<W> I<*> Delete all watch-expressions.
7570 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7571 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7572 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7573 B<x> I<expr> Evals expression in list context, dumps the result.
7574 B<m> I<expr> Evals expression in list context, prints methods callable
7575 on the first element of the result.
7576 B<m> I<class> Prints methods callable via the given class.
7577 B<M> Show versions of loaded modules.
7578 B<i> I<class> Prints nested parents of given class.
7579 B<e> Display current thread id.
7580 B<E> Display all thread ids the current one will be identified: <n>.
7581 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7583 B<<> ? List Perl commands to run before each prompt.
7584 B<<> I<expr> Define Perl command to run before each prompt.
7585 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7586 B<< *> Delete the list of perl commands to run before each prompt.
7587 B<>> ? List Perl commands to run after each prompt.
7588 B<>> I<expr> Define Perl command to run after each prompt.
7589 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7590 B<>>B< *> Delete the list of Perl commands to run after each prompt.
7591 B<{> I<db_command> Define debugger command to run before each prompt.
7592 B<{> ? List debugger commands to run before each prompt.
7593 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7594 B<{ *> Delete the list of debugger commands to run before each prompt.
7595 B<$prc> I<number> Redo a previous command (default previous command).
7596 B<$prc> I<-number> Redo number'th-to-last command.
7597 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7598 See 'B<O> I<recallCommand>' too.
7599 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7604 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7606 See 'B<O> I<shellBang>' too.
7607 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7608 B<save> I<file> Save current debugger session (actual history) to I<file>.
7609 B<rerun> Rerun session to current position.
7610 B<rerun> I<n> Rerun session to numbered command.
7611 B<rerun> I<-n> Rerun session to number'th-to-last command.
7612 B<H> I<-number> Display last number commands (default all).
7613 B<H> I<*> Delete complete history.
7614 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7615 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7616 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarily select()ed as well.
7617 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7618 I<command> Execute as a perl statement in current package.
7619 B<R> Pure-man-restart of debugger, some of debugger state
7620 and command-line options may be lost.
7621 Currently the following settings are preserved:
7622 history, breakpoints and actions, debugger B<O>ptions
7623 and the following command-line options: I<-w>, I<-I>, I<-e>.
7625 B<o> [I<opt>] ... Set boolean option to true
7626 B<o> [I<opt>B<?>] Query options
7627 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7628 Set options. Use quotes if spaces in value.
7629 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7630 I<pager> program for output of \"|cmd\";
7631 I<tkRunning> run Tk while prompting (with ReadLine);
7632 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7633 I<inhibit_exit> Allows stepping off the end of the script.
7634 I<ImmediateStop> Debugger should stop as early as possible.
7635 I<RemotePort> Remote hostname:port for remote debugging
7636 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7637 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7638 I<compactDump>, I<veryCompact> change style of array and hash dump;
7639 I<globPrint> whether to print contents of globs;
7640 I<DumpDBFiles> dump arrays holding debugged files;
7641 I<DumpPackages> dump symbol tables of packages;
7642 I<DumpReused> dump contents of \"reused\" addresses;
7643 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7644 I<bareStringify> Do not print the overload-stringified value;
7645 Other options include:
7646 I<PrintRet> affects printing of return value after B<r> command,
7647 I<frame> affects printing messages on subroutine entry/exit.
7648 I<AutoTrace> affects printing messages on possible breaking points.
7649 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7650 I<ornaments> affects screen appearance of the command line.
7651 I<CreateTTY> bits control attempts to create a new TTY on events:
7652 1: on fork() 2: debugger is started inside debugger
7654 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7655 You can put additional initialization options I<TTY>, I<noTTY>,
7656 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7657 B<R> after you set them).
7659 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7660 B<h> Summary of debugger commands.
7661 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7662 B<h h> Long help for debugger commands
7663 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7664 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7665 Set B<\$DB::doccmd> to change viewer.
7667 Type '|h h' for a paged display if this was too hard to read.
7669 "; # Fix balance of vi % matching: }}}}
7671 # note: tabs in the following section are not-so-helpful
7672 $summary = <<"END_SUM";
7673 I<List/search source lines:> I<Control script execution:>
7674 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7675 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7676 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
7677 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7678 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7679 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
7680 I<Debugger controls:> B<L> List break/watch/actions
7681 B<o> [...] Set debugger options B<t> [I<n>] [I<expr>] Toggle trace [max depth] ][trace expr]
7682 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7683 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
7684 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7685 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
7686 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
7687 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
7688 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7689 B<q> or B<^D> Quit B<R> Attempt a restart
7690 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7691 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7692 B<p> I<expr> Print expression (uses script's current package).
7693 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7694 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7695 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
7696 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7697 B<e> Display thread id B<E> Display all thread ids.
7698 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7701 # ')}}; # Fix balance of vi % matching
7703 # and this is really numb...
7706 B<s> [I<expr>] Single step [in I<expr>].
7707 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7708 B<CR>> Repeat last B<n> or B<s> command.
7709 B<r> Return from current subroutine.
7710 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7711 at the specified position.
7712 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7713 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7714 B<l> I<line> List single I<line>.
7715 B<l> I<subname> List first window of lines from subroutine.
7716 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
7717 B<l> List next window of lines.
7718 B<-> List previous window of lines.
7719 B<w> [I<line>] List window around I<line>.
7720 B<.> Return to the executed line.
7721 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
7722 I<filename> may be either the full name of the file, or a regular
7723 expression matching the full file name:
7724 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
7725 Evals (with saved bodies) are considered to be filenames:
7726 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
7727 (in the order of execution).
7728 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
7729 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
7730 B<L> List all breakpoints and actions.
7731 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
7732 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth) .
7733 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
7734 B<b> [I<line>] [I<condition>]
7735 Set breakpoint; I<line> defaults to the current execution line;
7736 I<condition> breaks if it evaluates to true, defaults to '1'.
7737 B<b> I<subname> [I<condition>]
7738 Set breakpoint at first line of subroutine.
7739 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
7740 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
7741 B<b> B<postpone> I<subname> [I<condition>]
7742 Set breakpoint at first line of subroutine after
7744 B<b> B<compile> I<subname>
7745 Stop after the subroutine is compiled.
7746 B<d> [I<line>] Delete the breakpoint for I<line>.
7747 B<D> Delete all breakpoints.
7748 B<a> [I<line>] I<command>
7749 Set an action to be done before the I<line> is executed;
7750 I<line> defaults to the current execution line.
7751 Sequence is: check for breakpoint/watchpoint, print line
7752 if necessary, do action, prompt user if necessary,
7754 B<a> [I<line>] Delete the action for I<line>.
7755 B<A> Delete all actions.
7756 B<W> I<expr> Add a global watch-expression.
7757 B<W> Delete all watch-expressions.
7758 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
7759 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
7760 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
7761 B<x> I<expr> Evals expression in list context, dumps the result.
7762 B<m> I<expr> Evals expression in list context, prints methods callable
7763 on the first element of the result.
7764 B<m> I<class> Prints methods callable via the given class.
7766 B<<> ? List Perl commands to run before each prompt.
7767 B<<> I<expr> Define Perl command to run before each prompt.
7768 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
7769 B<>> ? List Perl commands to run after each prompt.
7770 B<>> I<expr> Define Perl command to run after each prompt.
7771 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
7772 B<{> I<db_command> Define debugger command to run before each prompt.
7773 B<{> ? List debugger commands to run before each prompt.
7774 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
7775 B<$prc> I<number> Redo a previous command (default previous command).
7776 B<$prc> I<-number> Redo number'th-to-last command.
7777 B<$prc> I<pattern> Redo last command that started with I<pattern>.
7778 See 'B<O> I<recallCommand>' too.
7779 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
7784 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
7786 See 'B<O> I<shellBang>' too.
7787 B<source> I<file> Execute I<file> containing debugger commands (may nest).
7788 B<H> I<-number> Display last number commands (default all).
7789 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
7790 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
7791 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
7792 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
7793 I<command> Execute as a perl statement in current package.
7794 B<v> Show versions of loaded modules.
7795 B<R> Pure-man-restart of debugger, some of debugger state
7796 and command-line options may be lost.
7797 Currently the following settings are preserved:
7798 history, breakpoints and actions, debugger B<O>ptions
7799 and the following command-line options: I<-w>, I<-I>, I<-e>.
7801 B<O> [I<opt>] ... Set boolean option to true
7802 B<O> [I<opt>B<?>] Query options
7803 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
7804 Set options. Use quotes if spaces in value.
7805 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
7806 I<pager> program for output of \"|cmd\";
7807 I<tkRunning> run Tk while prompting (with ReadLine);
7808 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
7809 I<inhibit_exit> Allows stepping off the end of the script.
7810 I<ImmediateStop> Debugger should stop as early as possible.
7811 I<RemotePort> Remote hostname:port for remote debugging
7812 The following options affect what happens with B<V>, B<X>, and B<x> commands:
7813 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
7814 I<compactDump>, I<veryCompact> change style of array and hash dump;
7815 I<globPrint> whether to print contents of globs;
7816 I<DumpDBFiles> dump arrays holding debugged files;
7817 I<DumpPackages> dump symbol tables of packages;
7818 I<DumpReused> dump contents of \"reused\" addresses;
7819 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
7820 I<bareStringify> Do not print the overload-stringified value;
7821 Other options include:
7822 I<PrintRet> affects printing of return value after B<r> command,
7823 I<frame> affects printing messages on subroutine entry/exit.
7824 I<AutoTrace> affects printing messages on possible breaking points.
7825 I<maxTraceLen> gives max length of evals/args listed in stack trace.
7826 I<ornaments> affects screen appearance of the command line.
7827 I<CreateTTY> bits control attempts to create a new TTY on events:
7828 1: on fork() 2: debugger is started inside debugger
7830 During startup options are initialized from \$ENV{PERLDB_OPTS}.
7831 You can put additional initialization options I<TTY>, I<noTTY>,
7832 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
7833 B<R> after you set them).
7835 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
7836 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
7837 B<h h> Summary of debugger commands.
7838 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
7839 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
7840 Set B<\$DB::doccmd> to change viewer.
7842 Type '|h' for a paged display if this was too hard to read.
7844 "; # Fix balance of vi % matching: }}}}
7846 # note: tabs in the following section are not-so-helpful
7847 $pre580_summary = <<"END_SUM";
7848 I<List/search source lines:> I<Control script execution:>
7849 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
7850 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
7851 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
7852 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
7853 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
7854 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
7855 I<Debugger controls:> B<L> List break/watch/actions
7856 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
7857 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
7858 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
7859 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
7860 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
7861 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
7862 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
7863 B<q> or B<^D> Quit B<R> Attempt a restart
7864 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
7865 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
7866 B<p> I<expr> Print expression (uses script's current package).
7867 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
7868 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
7869 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
7870 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
7871 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
7874 # ')}}; # Fix balance of vi % matching
7876 } ## end sub sethelp
7878 =head2 C<print_help()>
7880 Most of what C<print_help> does is just text formatting. It finds the
7881 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
7882 terminal control characters to simulate them (courtesy of
7883 C<Term::ReadLine::TermCap>).
7888 my $help_str = shift;
7890 # Restore proper alignment destroyed by eeevil I<> and B<>
7891 # ornaments: A pox on both their houses!
7893 # A help command will have everything up to and including
7894 # the first tab sequence padded into a field 16 (or if indented 20)
7895 # wide. If it's wider than that, an extra space will be added.
7897 ^ # only matters at start of line
7898 ( \040{4} | \t )* # some subcommands are indented
7899 ( < ? # so <CR> works
7900 [BI] < [^\t\n] + ) # find an eeevil ornament
7901 ( \t+ ) # original separation, discarded
7902 ( .* ) # this will now start (no earlier) than
7905 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
7906 my $clean = $command;
7907 $clean =~ s/[BI]<([^>]*)>/$1/g;
7909 # replace with this whole string:
7910 ($leadwhite ? " " x 4 : "")
7912 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
7917 $help_str =~ s{ # handle bold ornaments
7918 B < ( [^>] + | > ) >
7920 $Term::ReadLine::TermCap::rl_term_set[2]
7922 . $Term::ReadLine::TermCap::rl_term_set[3]
7925 $help_str =~ s{ # handle italic ornaments
7926 I < ( [^>] + | > ) >
7928 $Term::ReadLine::TermCap::rl_term_set[0]
7930 . $Term::ReadLine::TermCap::rl_term_set[1]
7934 print {$OUT} $help_str;
7937 } ## end sub print_help
7941 This routine does a lot of gyrations to be sure that the pager is C<less>.
7942 It checks for C<less> masquerading as C<more> and records the result in
7943 C<$fixed_less> so we don't have to go through doing the stats again.
7947 use vars qw($fixed_less);
7950 if ($pager =~ /\bless\b/)
7954 elsif ($pager =~ /\bmore\b/)
7956 # Nope, set to more. See what's out there.
7957 my @st_more = stat('/usr/bin/more');
7958 my @st_less = stat('/usr/bin/less');
7960 # is it really less, pretending to be more?
7964 && $st_more[0] == $st_less[0]
7965 && $st_more[1] == $st_less[1]
7975 # We already know if this is set.
7976 return if $fixed_less;
7978 # changes environment!
7979 # 'r' added so we don't do (slow) stats again.
7980 $fixed_less = 1 if _calc_is_less();
7983 } ## end sub fix_less
7985 =head1 DIE AND WARN MANAGEMENT
7989 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
7990 to debug a debugger problem.
7992 It does its best to report the error that occurred, and then forces the
7993 program, debugger, and everything to die.
7999 # No entry/exit messages.
8002 # No return value prints.
8005 # set the abort signal handling to the default (just terminate).
8006 $SIG{'ABRT'} = 'DEFAULT';
8008 # If we enter the signal handler recursively, kill myself with an
8009 # abort signal (so we just terminate).
8010 kill 'ABRT', $$ if $panic++;
8012 # If we can show detailed info, do so.
8013 if ( defined &Carp::longmess ) {
8015 # Don't recursively enter the warn handler, since we're carping.
8016 local $SIG{__WARN__} = '';
8018 # Skip two levels before reporting traceback: we're skipping
8019 # mydie and confess.
8020 local $Carp::CarpLevel = 2; # mydie + confess
8022 # Tell us all about it.
8023 &warn( Carp::longmess("Signal @_") );
8026 # No Carp. Tell us about the signal as best we can.
8029 print $DB::OUT "Got signal @_\n";
8034 } ## end sub diesignal
8038 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
8039 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
8045 # No entry/exit trace.
8048 # No return value printing.
8051 # Turn off warn and die handling to prevent recursive entries to this
8053 local $SIG{__WARN__} = '';
8054 local $SIG{__DIE__} = '';
8056 # Load Carp if we can. If $^S is false (current thing being compiled isn't
8057 # done yet), we may not be able to do a require.
8058 eval { require Carp }
8059 if defined $^S; # If error/warning during compilation,
8060 # require may be broken.
8062 # Use the core warn() unless Carp loaded OK.
8064 "\nCannot print stack trace, load with -MCarp option to see stack" ),
8066 unless defined &Carp::longmess;
8068 # Save the current values of $single and $trace, and then turn them off.
8069 my ( $mysingle, $mytrace ) = ( $single, $trace );
8073 # We can call Carp::longmess without its being "debugged" (which we
8074 # don't want - we just want to use it!). Capture this for later.
8075 my $mess = Carp::longmess(@_);
8077 # Restore $single and $trace to their original values.
8078 ( $single, $trace ) = ( $mysingle, $mytrace );
8080 # Use the debugger's own special way of printing warnings to print
8081 # the stack trace message.
8087 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
8088 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
8089 single stepping and tracing during the call to C<Carp::longmess> to avoid
8090 debugging it - we just want to use it.
8092 If C<dieLevel> is zero, we let the program being debugged handle the
8093 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
8094 the debugger takes over all exception handling, printing a backtrace and
8095 displaying the exception via its C<dbwarn()> routine.
8102 local $SIG{__DIE__} = '';
8103 local $SIG{__WARN__} = '';
8107 if ( $dieLevel > 2 ) {
8108 local $SIG{__WARN__} = \&dbwarn;
8109 &warn(@_); # Yell no matter what
8112 if ( $dieLevel < 2 ) {
8113 die @_ if $^S; # in eval propagate
8116 # The code used to check $^S to see if compilation of the current thing
8117 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
8118 eval { require Carp };
8121 "\nCannot print stack trace, load with -MCarp option to see stack" )
8122 unless defined &Carp::longmess;
8124 # We do not want to debug this chunk (automatic disabling works
8125 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
8126 # get the stack trace from Carp::longmess (if possible), restore $signal
8127 # and $trace, and then die with the stack trace.
8128 my ( $mysingle, $mytrace ) = ( $single, $trace );
8134 package Carp; # Do not include us in the list
8135 eval { $mess = Carp::longmess(@_); };
8137 ( $single, $trace ) = ( $mysingle, $mytrace );
8141 =head2 C<warnlevel()>
8143 Set the C<$DB::warnLevel> variable that stores the value of the
8144 C<warnLevel> option. Calling C<warnLevel()> with a positive value
8145 results in the debugger taking over all warning handlers. Setting
8146 C<warnLevel> to zero leaves any warning handlers set up by the program
8147 being debugged in place.
8153 my $prevwarn = $SIG{__WARN__} unless $warnLevel;
8156 $SIG{__WARN__} = \&DB::dbwarn;
8159 $SIG{__WARN__} = $prevwarn;
8161 undef $SIG{__WARN__};
8165 } ## end sub warnLevel
8169 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
8170 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
8171 zero lets you use your own C<die()> handler.
8178 my $prevdie = $SIG{__DIE__} unless $dieLevel;
8182 # Always set it to dbdie() for non-zero values.
8183 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
8185 # No longer exists, so don't try to use it.
8186 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
8188 # If we've finished initialization, mention that stack dumps
8189 # are enabled, If dieLevel is 1, we won't stack dump if we die
8191 print $OUT "Stack dump during die enabled",
8192 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
8195 # XXX This is probably obsolete, given that diehard() is gone.
8196 print $OUT "Dump printed too.\n" if $dieLevel > 2;
8197 } ## end if ($dieLevel)
8199 # Put the old one back if there was one.
8201 $SIG{__DIE__} = $prevdie;
8202 print $OUT "Default die handler restored.\n";
8204 undef $SIG{__DIE__};
8205 print $OUT "Die handler removed.\n";
8209 } ## end sub dieLevel
8211 =head2 C<signalLevel>
8213 Number three in a series: set C<signalLevel> to zero to keep your own
8214 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
8215 takes over and handles them with C<DB::diesignal()>.
8221 my $prevsegv = $SIG{SEGV} unless $signalLevel;
8222 my $prevbus = $SIG{BUS} unless $signalLevel;
8223 $signalLevel = shift;
8225 $SIG{SEGV} = \&DB::diesignal;
8226 $SIG{BUS} = \&DB::diesignal;
8229 $SIG{SEGV} = $prevsegv;
8230 $SIG{BUS} = $prevbus;
8234 } ## end sub signalLevel
8236 =head1 SUBROUTINE DECODING SUPPORT
8238 These subroutines are used during the C<x> and C<X> commands to try to
8239 produce as much information as possible about a code reference. They use
8240 L<Devel::Peek> to try to find the glob in which this code reference lives
8241 (if it does) - this allows us to actually code references which correspond
8242 to named subroutines (including those aliased via glob assignment).
8244 =head2 C<CvGV_name()>
8246 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
8247 via that routine. If this fails, return the reference again (when the
8248 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
8254 my $name = CvGV_name_or_bust($in);
8255 defined $name ? $name : $in;
8258 =head2 C<CvGV_name_or_bust> I<coderef>
8260 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
8261 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
8262 find a glob for this ref.
8264 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
8268 use vars qw($skipCvGV);
8270 sub CvGV_name_or_bust {
8272 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
8273 return unless ref $in;
8274 $in = \&$in; # Hard reference...
8275 eval { require Devel::Peek; 1 } or return;
8276 my $gv = Devel::Peek::CvGV($in) or return;
8277 *$gv{PACKAGE} . '::' . *$gv{NAME};
8278 } ## end sub CvGV_name_or_bust
8282 A utility routine used in various places; finds the file where a subroutine
8283 was defined, and returns that filename and a line-number range.
8285 Tries to use C<@sub> first; if it can't find it there, it tries building a
8286 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
8287 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
8288 this way, it brute-force searches C<%sub>, checking for identical references.
8292 sub _find_sub_helper {
8295 return unless defined &$subr;
8296 my $name = CvGV_name_or_bust($subr);
8298 $data = $sub{$name} if defined $name;
8299 return $data if defined $data;
8302 $subr = \&$subr; # Hard reference
8305 $s = $_, last if $subr eq \&$_;
8320 return ( $sub{$subr} || _find_sub_helper($subr) );
8321 } ## end sub find_sub
8325 A subroutine that uses the utility function C<methods_via> to find all the
8326 methods in the class corresponding to the current reference and in
8335 # Figure out the class - either this is the class or it's a reference
8336 # to something blessed into that class.
8338 $class = ref $class if ref $class;
8342 # Show the methods that this class has.
8343 methods_via( $class, '', 1 );
8345 # Show the methods that UNIVERSAL has.
8346 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
8347 } ## end sub methods
8349 =head2 C<methods_via($class, $prefix, $crawl_upward)>
8351 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
8352 all the parent class methods. C<$class> is the name of the next class to
8353 try; C<$prefix> is the message prefix, which gets built up as we go up the
8354 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
8355 higher in the C<@ISA> tree, 0 if we should stop.
8361 # If we've processed this class already, just quit.
8363 return if $seen{$class}++;
8365 # This is a package that is contributing the methods we're about to print.
8367 my $prepend = $prefix ? "via $prefix: " : '';
8370 # Extract from all the symbols in this class.
8371 my $class_ref = do { no strict "refs"; \%{$class . '::'} };
8372 while (my ($name, $glob) = each %$class_ref) {
8373 # references directly in the symbol table are Proxy Constant
8374 # Subroutines, and are by their very nature defined
8375 # Otherwise, check if the thing is a typeglob, and if it is, it decays
8376 # to a subroutine reference, which can be tested by defined.
8377 # $glob might also be the value -1 (from sub foo;)
8378 # or (say) '$$' (from sub foo ($$);)
8379 # \$glob will be SCALAR in both cases.
8380 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob))
8381 && !$seen{$name}++) {
8382 push @to_print, "$prepend$name\n";
8389 print $DB::OUT $_ foreach sort @to_print;
8392 # If the $crawl_upward argument is false, just quit here.
8393 return unless shift;
8395 # $crawl_upward true: keep going up the tree.
8396 # Find all the classes this one is a subclass of.
8397 my $class_ISA_ref = do { no strict "refs"; \@{"${class}::ISA"} };
8398 for my $name ( @$class_ISA_ref ) {
8400 # Set up the new prefix.
8401 $prepend = $prefix ? $prefix . " -> $name" : $name;
8403 # Crawl up the tree and keep trying to crawl up.
8404 methods_via( $name, $prepend, 1 );
8406 } ## end sub methods_via
8408 =head2 C<setman> - figure out which command to use to show documentation
8410 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8415 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|NetWare)\z/s
8416 ? "man" # O Happy Day!
8417 : "perldoc"; # Alas, poor unfortunates
8420 =head2 C<runman> - run the appropriate command to show documentation
8422 Accepts a man page name; runs the appropriate command to display it (set up
8423 during debugger initialization). Uses C<DB::system> to avoid mucking up the
8424 program's STDIN and STDOUT.
8428 my %_is_in_pods = (map { $_ => 1 }
8566 &system("$doccmd $doccmd");
8570 # this way user can override, like with $doccmd="man -Mwhatever"
8571 # or even just "man " to disable the path check.
8572 unless ( $doccmd eq 'man' ) {
8573 &system("$doccmd $page");
8577 $page = 'perl' if lc($page) eq 'help';
8580 my $man1dir = $Config::Config{'man1dir'};
8581 my $man3dir = $Config::Config{'man3dir'};
8582 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
8584 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
8585 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
8586 chop $manpath if $manpath;
8588 # harmless if missing, I figure
8589 my $oldpath = $ENV{MANPATH};
8590 $ENV{MANPATH} = $manpath if $manpath;
8591 my $nopathopt = $^O =~ /dunno what goes here/;
8596 # I just *know* there are men without -M
8597 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8602 unless ( $page =~ /^perl\w/ ) {
8603 # do it this way because its easier to slurp in to keep up to date - clunky though.
8604 if (exists($_is_in_pods{$page})) {
8605 CORE::system( $doccmd,
8606 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8610 } ## end if (CORE::system($doccmd...
8611 if ( defined $oldpath ) {
8612 $ENV{MANPATH} = $manpath;
8615 delete $ENV{MANPATH};
8619 #use Carp; # This did break, left for debugging
8621 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
8623 Because of the way the debugger interface to the Perl core is designed, any
8624 debugger package globals that C<DB::sub()> requires have to be defined before
8625 any subroutines can be called. These are defined in the second C<BEGIN> block.
8627 This block sets things up so that (basically) the world is sane
8628 before the debugger starts executing. We set up various variables that the
8629 debugger has to have set up before the Perl core starts running:
8635 The debugger's own filehandles (copies of STD and STDOUT for now).
8639 Characters for shell escapes, the recall command, and the history command.
8643 The maximum recursion depth.
8647 The size of a C<w> command's window.
8651 The before-this-line context to be printed in a C<v> (view a window around this line) command.
8655 The fact that we're not in a sub at all right now.
8659 The default SIGINT handler for the debugger.
8663 The appropriate value of the flag in C<$^D> that says the debugger is running
8667 The current debugger recursion level
8671 The list of postponed items and the C<$single> stack (XXX define this)
8675 That we want no return values and no subroutine entry/exit trace.
8681 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
8683 use vars qw($db_stop);
8685 BEGIN { # This does not compile, alas. (XXX eh?)
8686 $IN = \*STDIN; # For bugs before DB::OUT has been opened
8687 $OUT = \*STDERR; # For errors before DB::OUT has been opened
8689 # Define characters used by command parsing.
8690 $sh = '!'; # Shell escape (does not work)
8691 $rc = ','; # Recall command (does not work)
8692 @hist = ('?'); # Show history (does not work)
8693 @truehist = (); # Can be saved for replay (per session)
8695 # This defines the point at which you get the 'deep recursion'
8696 # warning. It MUST be defined or the debugger will not load.
8699 # Number of lines around the current one that are shown in the
8703 # How much before-the-current-line context the 'v' command should
8704 # use in calculating the start of the window it will display.
8707 # We're not in any sub yet, but we need this to be a defined value.
8710 # Set up the debugger's interrupt handler. It simply sets a flag
8711 # ($signal) that DB::DB() will check before each command is executed.
8712 $SIG{INT} = \&DB::catch;
8714 # The following lines supposedly, if uncommented, allow the debugger to
8715 # debug itself. Perhaps we can try that someday.
8716 # This may be enabled to debug debugger:
8717 #$warnLevel = 1 unless defined $warnLevel;
8718 #$dieLevel = 1 unless defined $dieLevel;
8719 #$signalLevel = 1 unless defined $signalLevel;
8721 # This is the flag that says "a debugger is running, please call
8722 # DB::DB and DB::sub". We will turn it on forcibly before we try to
8723 # execute anything in the user's context, because we always want to
8725 $db_stop = 0; # Compiler warning ...
8726 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
8728 # This variable records how many levels we're nested in debugging. Used
8729 # Used in the debugger prompt, and in determining whether it's all over or
8731 $level = 0; # Level of recursive debugging
8733 # "Triggers bug (?) in perl if we postpone this until runtime."
8734 # XXX No details on this yet, or whether we should fix the bug instead
8735 # of work around it. Stay tuned.
8738 # Used to track the current stack depth using the auto-stacked-variable
8740 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
8742 # Don't print return values on exiting a subroutine.
8745 # No extry/exit tracing.
8750 BEGIN { $^W = $ini_warn; } # Switch warnings back
8752 =head1 READLINE SUPPORT - COMPLETION FUNCTION
8756 C<readline> support - adds command completion to basic C<readline>.
8758 Returns a list of possible completions to C<readline> when invoked. C<readline>
8759 will print the longest common substring following the text already entered.
8761 If there is only a single possible completion, C<readline> will use it in full.
8763 This code uses C<map> and C<grep> heavily to create lists of possible
8764 completion. Think LISP in this section.
8770 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
8771 # $text is the text to be completed.
8772 # $line is the incoming line typed by the user.
8773 # $start is the start of the text to be completed in the incoming line.
8774 my ( $text, $line, $start ) = @_;
8776 # Save the initial text.
8777 # The search pattern is current package, ::, extract the next qualifier
8778 # Prefix and pack are set to undef.
8779 my ( $itext, $search, $prefix, $pack ) =
8780 ( $text, "^\Q${package}::\E([^:]+)\$" );
8782 =head3 C<b postpone|compile>
8788 Find all the subroutines that might match in this package
8792 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
8796 Include all the rest of the subs that are known
8800 C<grep> out the ones that match the text we have so far
8804 Return this as the list of possible completions
8810 return sort grep /^\Q$text/, ( keys %sub ),
8811 qw(postpone load compile), # subroutines
8812 ( map { /$search/ ? ($1) : () } keys %sub )
8813 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
8817 Get all the possible files from C<@INC> as it currently stands and
8818 select the ones that match the text so far.
8822 return sort grep /^\Q$text/, values %INC # files
8823 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
8825 =head3 C<V> (list variable) and C<m> (list modules)
8827 There are two entry points for these commands:
8829 =head4 Unqualified package names
8831 Get the top-level packages and grab everything that matches the text
8832 so far. For each match, recursively complete the partial packages to
8833 get all possible matching packages. Return this sorted list.
8837 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8838 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
8839 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
8841 =head4 Qualified package names
8843 Take a partially-qualified package and find all subpackages for it
8844 by getting all the subpackages for the package so far, matching all
8845 the subpackages against the text, and discarding all of them which
8846 start with 'main::'. Return this list.
8850 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
8851 grep !/^main::/, grep /^\Q$text/,
8852 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () }
8853 do { no strict 'refs'; keys %{ $prefix . '::' } }
8854 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
8855 and $text =~ /^(.*[^:])::?(\w*)$/
8858 =head3 C<f> - switch files
8860 Here, we want to get a fully-qualified filename for the C<f> command.
8865 =item 1. The original source file itself
8867 =item 2. A file from C<@INC>
8869 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
8875 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
8876 # We might possibly want to switch to an eval (which has a "filename"
8877 # like '(eval 9)'), so we may need to clean up the completion text
8878 # before proceeding.
8879 $prefix = length($1) - length($text);
8884 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
8885 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
8886 out of C<%main::>, add the initial source file, and extract the ones that
8887 match the completion text so far.
8892 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
8894 } ## end if ($line =~ /^\|*f\s+(.*)/)
8896 =head3 Subroutine name completion
8898 We look through all of the defined subs (the keys of C<%sub>) and
8899 return both all the possible matches to the subroutine name plus
8900 all the matches qualified to the current package.
8904 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
8905 $text = substr $text, 1;
8907 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
8909 map { /$search/ ? ($1) : () }
8912 } ## end if ((substr $text, 0, ...
8914 =head3 Scalar, array, and hash completion: partially qualified package
8916 Much like the above, except we have to do a little more cleanup:
8920 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
8928 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
8932 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
8938 Figure out the prefix vs. what needs completing.
8942 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
8949 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
8955 map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
8963 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.
8967 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
8968 return db_complete( $out[0], $line, $start );
8971 # Return the list of possibles.
8974 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
8980 =head3 Symbol completion: current package or package C<main>.
8984 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
8991 If it's C<main>, delete main to just get C<::> leading.
8995 $pack = ( $package eq 'main' ? '' : $package ) . '::';
9001 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
9005 $prefix = substr $text, 0, 1;
9006 $text = substr $text, 1;
9014 We look for the lexical scope above DB::DB and auto-complete lexical variables
9015 if PadWalker could be loaded.
9019 if (not $text =~ /::/ and eval { require PadWalker } ) {
9022 my @info = caller($level);
9026 last if $info[3] eq 'DB::DB';
9029 my $lexicals = PadWalker::peek_my($level);
9030 push @out, grep /^\Q$prefix$text/, keys %$lexicals;
9038 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
9042 push @out, map "$prefix$_", grep /^\Q$text/,
9043 ( grep /^_?[a-zA-Z]/, keys %$pack ),
9044 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
9048 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
9054 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9055 return db_complete( $out[0], $line, $start );
9058 # Return the list of possibles.
9060 } ## end if ($text =~ /^[\$@%]/)
9064 We use C<option_val()> to look up the current value of the option. If there's
9065 only a single value, we complete the command in such a way that it is a
9066 complete command for setting the option in question. If there are multiple
9067 possible values, we generate a command consisting of the option plus a trailing
9068 question mark, which, if executed, will list the current value of the option.
9072 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
9073 { # Options after space
9074 # We look for the text to be matched in the list of possible options,
9075 # and fetch the current value.
9076 my @out = grep /^\Q$text/, @options;
9077 my $val = option_val( $out[0], undef );
9079 # Set up a 'query option's value' command.
9081 if ( not defined $val or $val =~ /[\n\r]/ ) {
9083 # There's really nothing else we can do.
9086 # We have a value. Create a proper option-setting command.
9087 elsif ( $val =~ /\s/ ) {
9089 # XXX This may be an extraneous variable.
9092 # We'll want to quote the string (because of the embedded
9093 # whtespace), but we want to make sure we don't end up with
9094 # mismatched quote characters. We try several possibilities.
9095 foreach my $l ( split //, qq/\"\'\#\|/ ) {
9097 # If we didn't find this quote character in the value,
9098 # quote it using this quote character.
9099 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
9101 } ## end elsif ($val =~ /\s/)
9103 # Don't need any quotes.
9108 # If there were multiple possible values, return '? ', which
9109 # makes the command into a query command. If there was just one,
9110 # have readline append that.
9111 $rl_attribs->{completer_terminator_character} =
9112 ( @out == 1 ? $out : '? ' );
9114 # Return list of possibilities.
9116 } ## end if ((substr $line, 0, ...
9118 =head3 Filename completion
9120 For entering filenames. We simply call C<readline>'s C<filename_list()>
9121 method with the completion text to get the possible completions.
9125 return $term->filename_list($text); # filenames
9127 } ## end sub db_complete
9129 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
9131 Functions that possibly ought to be somewhere else.
9141 print $OUT "Use 'q' to quit or 'R' to restart. 'h q' for details.\n";
9146 If we have $ini_pids, save it in the environment; else remove it from the
9147 environment. Used by the C<R> (restart) command.
9152 if ( defined($ini_pids) ) {
9153 $ENV{PERLDB_PIDS} = $ini_pids;
9156 delete( $ENV{PERLDB_PIDS} );
9158 } ## end sub clean_ENV
9160 # PERLDBf_... flag names from perl.h
9161 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
9164 %DollarCaretP_flags = (
9165 PERLDBf_SUB => 0x01, # Debug sub enter/exit
9166 PERLDBf_LINE => 0x02, # Keep line #
9167 PERLDBf_NOOPT => 0x04, # Switch off optimizations
9168 PERLDBf_INTER => 0x08, # Preserve more data
9169 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
9170 PERLDBf_SINGLE => 0x20, # Start with single-step on
9171 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
9172 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
9173 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
9174 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
9175 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"}
9176 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO
9178 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger
9179 # doesn't need to set it. It's provided for the benefit of profilers and
9180 # other code analysers.
9182 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
9185 sub parse_DollarCaretP_flags {
9190 foreach my $f ( split /\s*\|\s*/, $flags ) {
9192 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
9195 elsif ( $f =~ /^(\d+)$/ ) {
9198 elsif ( $f =~ /^DEFAULT$/i ) {
9199 $value = $DollarCaretP_flags{PERLDB_ALL};
9202 $f =~ /^(?:PERLDBf_)?(.*)$/i;
9203 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
9204 unless ( defined $value ) {
9206 "Unrecognized \$^P flag '$f'!\n",
9207 "Acceptable flags are: "
9208 . join( ', ', sort keys %DollarCaretP_flags ),
9209 ", and hexadecimal and decimal numbers.\n"
9219 sub expand_DollarCaretP_flags {
9220 my $DollarCaretP = shift;
9223 my $n = ( 1 << $_ );
9224 ( $DollarCaretP & $n )
9225 ? ( $DollarCaretP_flags_r{$n}
9226 || sprintf( '0x%x', $n ) )
9230 return @bits ? join( '|', @bits ) : 0;
9237 Rerun the current session to:
9239 rerun current position
9241 rerun 4 command number 4
9243 rerun -4 current command minus 4 (go back 4 steps)
9245 Whether this always makes sense, in the current context is unknowable, and is
9246 in part left as a useful exercise for the reader. This sub returns the
9247 appropriate arguments to rerun the current session.
9254 pop(@truehist); # strim
9255 unless (defined $truehist[$i]) {
9256 print "Unable to return to non-existent command: $i\n";
9258 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
9259 my @temp = @truehist; # store
9260 push(@DB::typeahead, @truehist); # saved
9261 @truehist = @hist = (); # flush
9262 @args = &restart(); # setup
9263 &get_list("PERLDB_HIST"); # clean
9264 &set_list("PERLDB_HIST", @temp); # reset
9271 Restarting the debugger is a complex operation that occurs in several phases.
9272 First, we try to reconstruct the command line that was used to invoke Perl
9278 # I may not be able to resurrect you, but here goes ...
9280 "Warning: some settings and command-line options may be lost!\n";
9281 my ( @script, @flags, $cl );
9283 # If warn was on before, turn it on again.
9284 push @flags, '-w' if $ini_warn;
9286 # Rebuild the -I flags that were on the initial
9289 push @flags, '-I', $_;
9292 # Turn on taint if it was on before.
9293 push @flags, '-T' if ${^TAINT};
9295 # Arrange for setting the old INC:
9296 # Save the current @init_INC in the environment.
9297 set_list( "PERLDB_INC", @ini_INC );
9299 # If this was a perl one-liner, go to the "file"
9300 # corresponding to the one-liner read all the lines
9301 # out of it (except for the first one, which is going
9302 # to be added back on again when 'perl -d' runs: that's
9303 # the 'require perl5db.pl;' line), and add them back on
9304 # to the command line to be executed.
9306 my $lines = *{$main::{'_<-e'}}{ARRAY};
9307 for ( 1 .. $#$lines ) { # The first line is PERL5DB
9308 chomp( $cl = $lines->[$_] );
9309 push @script, '-e', $cl;
9311 } ## end if ($0 eq '-e')
9313 # Otherwise we just reuse the original name we had
9321 After the command line has been reconstructed, the next step is to save
9322 the debugger's status in environment variables. The C<DB::set_list> routine
9323 is used to save aggregate variables (both hashes and arrays); scalars are
9324 just popped into environment variables directly.
9328 # If the terminal supported history, grab it and
9329 # save that in the environment.
9330 set_list( "PERLDB_HIST",
9331 $term->Features->{getHistory}
9335 # Find all the files that were visited during this
9336 # session (i.e., the debugger had magic hashes
9337 # corresponding to them) and stick them in the environment.
9338 my @had_breakpoints = keys %had_breakpoints;
9339 set_list( "PERLDB_VISITED", @had_breakpoints );
9341 # Save the debugger options we chose.
9342 set_list( "PERLDB_OPT", %option );
9343 # set_list( "PERLDB_OPT", options2remember() );
9345 # Save the break-on-loads.
9346 set_list( "PERLDB_ON_LOAD", %break_on_load );
9350 The most complex part of this is the saving of all of the breakpoints. They
9351 can live in an awful lot of places, and we have to go through all of them,
9352 find the breakpoints, and then save them in the appropriate environment
9353 variable via C<DB::set_list>.
9357 # Go through all the breakpoints and make sure they're
9360 for ( 0 .. $#had_breakpoints ) {
9362 # We were in this file.
9363 my $file = $had_breakpoints[$_];
9365 # Grab that file's magic line hash.
9366 *dbline = $main::{ '_<' . $file };
9368 # Skip out if it doesn't exist, or if the breakpoint
9369 # is in a postponed file (we'll do postponed ones
9371 next unless %dbline or $postponed_file{$file};
9373 # In an eval. This is a little harder, so we'll
9374 # do more processing on that below.
9375 ( push @hard, $file ), next
9376 if $file =~ /^\(\w*eval/;
9378 # XXX I have no idea what this is doing. Yet.
9380 @add = %{ $postponed_file{$file} }
9381 if $postponed_file{$file};
9383 # Save the list of all the breakpoints for this file.
9384 set_list( "PERLDB_FILE_$_", %dbline, @add );
9386 # Serialize the extra data %breakpoints_data hash.
9388 set_list( "PERLDB_FILE_ENABLED_$_",
9389 map { _is_breakpoint_enabled($file, $_) ? 1 : 0 }
9390 sort { $a <=> $b } keys(%dbline)
9392 } ## end for (0 .. $#had_breakpoints)
9394 # The breakpoint was inside an eval. This is a little
9395 # more difficult. XXX and I don't understand it.
9397 # Get over to the eval in question.
9398 *dbline = $main::{ '_<' . $_ };
9399 my ( $quoted, $sub, %subs, $line ) = quotemeta $_;
9400 for $sub ( keys %sub ) {
9401 next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/;
9402 $subs{$sub} = [ $1, $2 ];
9406 "No subroutines in $_, ignoring breakpoints.\n";
9409 LINES: for $line ( keys %dbline ) {
9411 # One breakpoint per sub only:
9412 my ( $offset, $sub, $found );
9413 SUBS: for $sub ( keys %subs ) {
9416 $line # Not after the subroutine
9418 not defined $offset # Not caught
9424 $offset = $line - $subs{$sub}->[0];
9425 $offset = "+$offset", last SUBS
9427 } ## end if ($subs{$sub}->[1] >=...
9428 } ## end for $sub (keys %subs)
9429 if ( defined $offset ) {
9430 $postponed{$found} =
9431 "break $offset if $dbline{$line}";
9435 "Breakpoint in $_:$line ignored: after all the subroutines.\n";
9437 } ## end for $line (keys %dbline)
9438 } ## end for (@hard)
9440 # Save the other things that don't need to be
9442 set_list( "PERLDB_POSTPONE", %postponed );
9443 set_list( "PERLDB_PRETYPE", @$pretype );
9444 set_list( "PERLDB_PRE", @$pre );
9445 set_list( "PERLDB_POST", @$post );
9446 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9448 # We are officially restarting.
9449 $ENV{PERLDB_RESTART} = 1;
9451 # We are junking all child debuggers.
9452 delete $ENV{PERLDB_PIDS}; # Restore ini state
9454 # Set this back to the initial pid.
9455 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9459 After all the debugger status has been saved, we take the command we built up
9460 and then return it, so we can C<exec()> it. The debugger will spot the
9461 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9462 from the environment.
9466 # And run Perl again. Add the "-d" flag, all the
9467 # flags we built up, the script (whether a one-liner
9468 # or a file), add on the -emacs flag for a slave editor,
9469 # and then the old arguments.
9471 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9477 =head1 END PROCESSING - THE C<END> BLOCK
9479 Come here at the very end of processing. We want to go into a
9480 loop where we allow the user to enter commands and interact with the
9481 debugger, but we don't want anything else to execute.
9483 First we set the C<$finished> variable, so that some commands that
9484 shouldn't be run after the end of program quit working.
9486 We then figure out whether we're truly done (as in the user entered a C<q>
9487 command, or we finished execution while running nonstop). If we aren't,
9488 we set C<$single> to 1 (causing the debugger to get control again).
9490 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9491 message and returns control to the debugger. Repeat.
9493 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9494 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9495 break, run to completion.).
9500 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9501 $fall_off_end = 1 unless $inhibit_exit;
9503 # Do not stop in at_exit() and destructors on exit:
9504 if ($fall_off_end or $runnonstop) {
9508 DB::fake::at_exit();
9512 =head1 PRE-5.8 COMMANDS
9514 Some of the commands changed function quite a bit in the 5.8 command
9515 realignment, so much so that the old code had to be replaced completely.
9516 Because we wanted to retain the option of being able to go back to the
9517 former command set, we moved the old code off to this section.
9519 There's an awful lot of duplicated code here. We've duplicated the
9520 comments to keep things clear.
9524 Does nothing. Used to I<turn off> commands.
9528 sub cmd_pre580_null {
9533 =head2 Old C<a> command.
9535 This version added actions if you supplied them, and deleted them
9544 # Argument supplied. Add the action.
9545 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9547 # If the line isn't there, use the current line.
9548 my $i = $1 || $line;
9551 # If there is an action ...
9554 # ... but the line isn't breakable, skip it.
9555 if ( $dbline[$i] == 0 ) {
9556 print $OUT "Line $i may not have an action.\n";
9560 # ... and the line is breakable:
9561 # Mark that there's an action in this file.
9562 $had_breakpoints{$filename} |= 2;
9564 # Delete any current action.
9565 $dbline{$i} =~ s/\0[^\0]*//;
9567 # Add the new action, continuing the line as needed.
9568 $dbline{$i} .= "\0" . action($j);
9570 } ## end if (length $j)
9572 # No action supplied.
9575 # Delete the action.
9576 $dbline{$i} =~ s/\0[^\0]*//;
9578 # Mark as having no break or action if nothing's left.
9579 delete $dbline{$i} if $dbline{$i} eq '';
9581 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
9582 } ## end sub cmd_pre580_a
9584 =head2 Old C<b> command
9596 if ( $cmd =~ /^load\b\s*(.*)/ ) {
9602 # b compile|postpone <some sub> [<condition>]
9603 # The interpreter actually traps this one for us; we just put the
9604 # necessary condition in the %postponed hash.
9605 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
9607 # Capture the condition if there is one. Make it true if none.
9608 my $cond = length $3 ? $3 : '1';
9610 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
9611 # if it was 'compile'.
9612 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
9614 # De-Perl4-ify the name - ' separators to ::.
9615 $subname =~ s/\'/::/g;
9617 # Qualify it into the current package unless it's already qualified.
9618 $subname = "${package}::" . $subname
9619 unless $subname =~ /::/;
9621 # Add main if it starts with ::.
9622 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
9624 # Save the break type for this sub.
9625 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
9626 } ## end elsif ($cmd =~ ...
9628 # b <sub name> [<condition>]
9629 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
9631 my $cond = length $2 ? $2 : '1';
9632 &cmd_b_sub( $subname, $cond );
9634 # b <line> [<condition>].
9635 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9636 my $i = $1 || $dbline;
9637 my $cond = length $2 ? $2 : '1';
9638 &cmd_b_line( $i, $cond );
9640 } ## end sub cmd_pre580_b
9642 =head2 Old C<D> command.
9644 Delete all breakpoints unconditionally.
9651 if ( $cmd =~ /^\s*$/ ) {
9652 print $OUT "Deleting all breakpoints...\n";
9654 # %had_breakpoints lists every file that had at least one
9657 for $file ( keys %had_breakpoints ) {
9659 # Switch to the desired file temporarily.
9660 local *dbline = $main::{ '_<' . $file };
9665 # For all lines in this file ...
9666 for my $i (1 .. $max) {
9668 # If there's a breakpoint or action on this line ...
9669 if ( defined $dbline{$i} ) {
9671 # ... remove the breakpoint.
9672 $dbline{$i} =~ s/^[^\0]+//;
9673 if ( $dbline{$i} =~ s/^\0?$// ) {
9675 # Remove the entry altogether if no action is there.
9678 } ## end if (defined $dbline{$i...
9679 } ## end for my $i (1 .. $max)
9681 # If, after we turn off the "there were breakpoints in this file"
9682 # bit, the entry in %had_breakpoints for this file is zero,
9683 # we should remove this file from the hash.
9684 if ( not $had_breakpoints{$file} &= ~1 ) {
9685 delete $had_breakpoints{$file};
9687 } ## end for $file (keys %had_breakpoints)
9689 # Kill off all the other breakpoints that are waiting for files that
9690 # haven't been loaded yet.
9692 undef %postponed_file;
9693 undef %break_on_load;
9694 } ## end if ($cmd =~ /^\s*$/)
9695 } ## end sub cmd_pre580_D
9697 =head2 Old C<h> command
9699 Print help. Defaults to printing the long-form help; the 5.8 version
9700 prints the summary by default.
9708 # Print the *right* help, long format.
9709 if ( $cmd =~ /^\s*$/ ) {
9710 print_help($pre580_help);
9713 # 'h h' - explicitly-requested summary.
9714 elsif ( $cmd =~ /^h\s*/ ) {
9715 print_help($pre580_summary);
9718 # Find and print a command's help.
9719 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
9720 my $asked = $1; # for proper errmsg
9721 my $qasked = quotemeta($asked); # for searching
9722 # XXX: finds CR but not <CR>
9726 (?:[IB]<) # Optional markup
9727 $qasked # The command name
9734 ( # The command help:
9736 (?:[IB]<) # Optional markup
9737 $qasked # The command name
9738 ([\s\S]*?) # Lines starting with tabs
9742 ) # Line not starting with space
9743 # (Next command's help)
9747 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
9751 print_help("B<$asked> is not a debugger command.\n");
9753 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
9754 } ## end sub cmd_pre580_h
9756 =head2 Old C<W> command
9758 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
9766 # Delete all watch expressions.
9767 if ( $cmd =~ /^$/ ) {
9769 # No watching is going on.
9772 # Kill all the watch expressions and values.
9773 @to_watch = @old_watch = ();
9776 # Add a watch expression.
9777 elsif ( $cmd =~ /^(.*)/s ) {
9779 # add it to the list to be watched.
9782 # Get the current value of the expression.
9783 # Doesn't handle expressions returning list values!
9785 my ($val) = DB::eval();
9786 $val = ( defined $val ) ? "'$val'" : 'undef';
9789 push @old_watch, $val;
9791 # We're watching stuff.
9794 } ## end elsif ($cmd =~ /^(.*)/s)
9795 } ## end sub cmd_pre580_W
9797 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
9799 The debugger used to have a bunch of nearly-identical code to handle
9800 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
9801 C<cmd_prepost> unify all this into one set of code to handle the
9802 appropriate actions.
9804 =head2 C<cmd_pre590_prepost>
9806 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
9807 do something destructive. In pre 5.8 debuggers, the default action was to
9808 delete all the actions.
9812 sub cmd_pre590_prepost {
9814 my $line = shift || '*';
9817 return &cmd_prepost( $cmd, $line, $dbline );
9818 } ## end sub cmd_pre590_prepost
9820 =head2 C<cmd_prepost>
9822 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
9823 Since the lists of actions are all held in arrays that are pointed to by
9824 references anyway, all we have to do is pick the right array reference and
9825 then use generic code to all, delete, or list actions.
9832 # No action supplied defaults to 'list'.
9833 my $line = shift || '?';
9835 # Figure out what to put in the prompt.
9838 # Make sure we have some array or another to address later.
9839 # This means that if ssome reason the tests fail, we won't be
9840 # trying to stash actions or delete them from the wrong place.
9843 # < - Perl code to run before prompt.
9844 if ( $cmd =~ /^\</o ) {
9845 $which = 'pre-perl';
9849 # > - Perl code to run after prompt.
9850 elsif ( $cmd =~ /^\>/o ) {
9851 $which = 'post-perl';
9855 # { - first check for properly-balanced braces.
9856 elsif ( $cmd =~ /^\{/o ) {
9857 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
9859 "$cmd is now a debugger command\nuse ';$cmd' if you mean Perl code\n";
9862 # Properly balanced. Pre-prompt debugger actions.
9864 $which = 'pre-debugger';
9867 } ## end elsif ( $cmd =~ /^\{/o )
9869 # Did we find something that makes sense?
9871 print $OUT "Confused by command: $cmd\n";
9878 if ( $line =~ /^\s*\?\s*$/o ) {
9881 # Nothing there. Complain.
9882 print $OUT "No $which actions.\n";
9886 # List the actions in the selected list.
9887 print $OUT "$which commands:\n";
9888 foreach my $action (@$aref) {
9889 print $OUT "\t$cmd -- $action\n";
9892 } ## end if ( $line =~ /^\s*\?\s*$/o)
9894 # Might be a delete.
9896 if ( length($cmd) == 1 ) {
9897 if ( $line =~ /^\s*\*\s*$/o ) {
9899 # It's a delete. Get rid of the old actions in the
9902 print $OUT "All $cmd actions cleared.\n";
9906 # Replace all the actions. (This is a <, >, or {).
9907 @$aref = action($line);
9909 } ## end if ( length($cmd) == 1)
9910 elsif ( length($cmd) == 2 ) {
9912 # Add the action to the line. (This is a <<, >>, or {{).
9913 push @$aref, action($line);
9917 # <<<, >>>>, {{{{{{ ... something not a command.
9919 "Confused by strange length of $which command($cmd)...\n";
9921 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
9923 } ## end sub cmd_prepost
9927 Contains the C<at_exit> routine that the debugger uses to issue the
9928 C<Debugged program terminated ...> message after the program completes. See
9929 the C<END> block documentation for more details.
9936 "Debugged program terminated. Use 'q' to quit or 'R' to restart.";
9939 package DB; # Do not trace this 1; below!