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<$filename>
275 is the expanded name of the C<require>d file (as found via C<%INC>).
277 =head3 IMPORTANT INTERNAL VARIABLES
281 Used to control when the debugger will attempt to acquire another TTY to be
286 =item * 1 - on C<fork()>
288 =item * 2 - debugger is started inside debugger
290 =item * 4 - on startup
296 The value -2 indicates that no return value should be printed.
297 Any other positive value causes C<DB::sub> to print return values.
301 The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
302 contents of C<@_> when C<DB::eval> is called.
306 Determines what messages (if any) will get printed when a subroutine (or eval)
307 is entered or exited.
311 =item * 0 - No enter/exit messages
313 =item * 1 - Print I<entering> messages on subroutine entry
315 =item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
317 =item * 4 - Extended messages: C<< <in|out> I<context>=I<fully-qualified sub name> from I<file>:I<line> >>. If no other flag is on, acts like 1+4.
319 =item * 8 - Adds parameter information to messages, and overloaded stringify and tied FETCH is enabled on the printed arguments. Ignored if C<4> is not on.
321 =item * 16 - Adds C<I<context> return from I<subname>: I<value>> messages on subroutine/eval exit. Ignored if C<4> is not on.
325 To get everything, use C<$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);
528 $header = "perl5db.pl version $VERSION";
530 =head1 DEBUGGER ROUTINES
534 This function replaces straight C<eval()> inside the debugger; it simplifies
535 the process of evaluating code in the user's context.
537 The code to be evaluated is passed via the package global variable
538 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
540 Before we do the C<eval()>, we preserve the current settings of C<$trace>,
541 C<$single>, C<$^D> and C<$usercontext>. The latter contains the
542 preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
543 user's current package, grabbed when C<DB::DB> got control. This causes the
544 proper context to be used when the eval is actually done. Afterward, we
545 restore C<$trace>, C<$single>, and C<$^D>.
547 Next we need to handle C<$@> without getting confused. We save C<$@> in a
548 local lexical, localize C<$saved[0]> (which is where C<save()> will put
549 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
550 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
551 considered sane by the debugger. If there was an C<eval()> error, we print
552 it on the debugger's output. If C<$onetimedump> is defined, we call
553 C<dumpit> if it's set to 'dump', or C<methods> if it's set to
554 'methods'. Setting it to something else causes the debugger to do the eval
555 but not print the result - handy if you want to do something else with it
556 (the "watch expressions" code does this to get the value of the watch
557 expression but not show it unless it matters).
559 In any case, we then return the list of output from C<eval> to the caller,
560 and unwinding restores the former version of C<$@> in C<@saved> as well
561 (the localization of C<$saved[0]> goes away at the end of this scope).
563 =head3 Parameters and variables influencing execution of DB::eval()
565 C<DB::eval> isn't parameterized in the standard way; this is to keep the
566 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
567 The variables listed below influence C<DB::eval()>'s execution directly.
571 =item C<$evalarg> - the thing to actually be eval'ed
573 =item C<$trace> - Current state of execution tracing
575 =item C<$single> - Current state of single-stepping
577 =item C<$onetimeDump> - what is to be displayed after the evaluation
579 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
583 The following variables are altered by C<DB::eval()> during its execution. They
584 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
588 =item C<@res> - used to capture output from actual C<eval>.
590 =item C<$otrace> - saved value of C<$trace>.
592 =item C<$osingle> - saved value of C<$single>.
594 =item C<$od> - saved value of C<$^D>.
596 =item C<$saved[0]> - saved value of C<$@>.
598 =item $\ - for output of C<$@> if there is an evaluation error.
602 =head3 The problem of lexicals
604 The context of C<DB::eval()> presents us with some problems. Obviously,
605 we want to be 'sandboxed' away from the debugger's internals when we do
606 the eval, but we need some way to control how punctuation variables and
607 debugger globals are used.
609 We can't use local, because the code inside C<DB::eval> can see localized
610 variables; and we can't use C<my> either for the same reason. The code
611 in this routine compromises and uses C<my>.
613 After this routine is over, we don't have user code executing in the debugger's
614 context, so we can use C<my> freely.
618 ############################################## Begin lexical danger zone
620 # 'my' variables used here could leak into (that is, be visible in)
621 # the context that the code being evaluated is executing in. This means that
622 # the code could modify the debugger's variables.
624 # Fiddling with the debugger's context could be Bad. We insulate things as
689 # Used to save @ARGV and extract any debugger-related flags.
692 # Used to prevent multiple entries to diesignal()
693 # (if for instance diesignal() itself dies)
696 # Used to prevent the debugger from running nonstop
700 sub _calc_usercontext {
703 # Cancel strict completely for the evaluated code, so the code
704 # the user evaluates won't be affected by it. (Shlomi Fish)
705 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @DB::saved;'
706 . "package $package;"; # this won't let them modify, alas
711 # 'my' would make it visible from user code
712 # but so does local! --tchrist
713 # Remember: this localizes @DB::res, not @main::res.
717 # Try to keep the user code from messing with us. Save these so that
718 # even if the eval'ed code changes them, we can put them back again.
719 # Needed because the user could refer directly to the debugger's
720 # package globals (and any 'my' variables in this containing scope)
721 # inside the eval(), and we want to try to stay safe.
722 local $otrace = $trace;
723 local $osingle = $single;
726 # Untaint the incoming eval() argument.
727 { ($evalarg) = $evalarg =~ /(.*)/s; }
729 # $usercontext built in DB::DB near the comment
730 # "set up the context for DB::eval ..."
731 # Evaluate and save any results.
732 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
734 # Restore those old values.
740 # Save the current value of $@, and preserve it in the debugger's copy
741 # of the saved precious globals.
744 # Since we're only saving $@, we only have to localize the array element
745 # that it will be stored in.
746 local $saved[0]; # Preserve the old value of $@
749 # Now see whether we need to report an error back to the user.
755 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
756 # are package globals.
757 elsif ($onetimeDump) {
758 if ( $onetimeDump eq 'dump' ) {
759 local $option{dumpDepth} = $onetimedumpDepth
760 if defined $onetimedumpDepth;
761 dumpit( $OUT, \@res );
763 elsif ( $onetimeDump eq 'methods' ) {
766 } ## end elsif ($onetimeDump)
770 ############################################## End lexical danger zone
772 # After this point it is safe to introduce lexicals.
773 # The code being debugged will be executing in its own context, and
774 # can't see the inside of the debugger.
776 # However, one should not overdo it: leave as much control from outside as
777 # possible. If you make something a lexical, it's not going to be addressable
778 # from outside the debugger even if you know its name.
780 # This file is automatically included if you do perl -d.
781 # It's probably not useful to include this yourself.
783 # Before venturing further into these twisty passages, it is
784 # wise to read the perldebguts man page or risk the ire of dragons.
786 # (It should be noted that perldebguts will tell you a lot about
787 # the underlying mechanics of how the debugger interfaces into the
788 # Perl interpreter, but not a lot about the debugger itself. The new
789 # comments in this code try to address this problem.)
791 # Note that no subroutine call is possible until &DB::sub is defined
792 # (for subroutines defined outside of the package DB). In fact the same is
793 # true if $deep is not defined.
795 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
797 # modified Perl debugger, to be run from Emacs in perldb-mode
798 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
799 # Johan Vromans -- upgrade to 4.0 pl 10
800 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
801 ########################################################################
803 =head1 DEBUGGER INITIALIZATION
805 The debugger starts up in phases.
809 First, it initializes the environment it wants to run in: turning off
810 warnings during its own compilation, defining variables which it will need
811 to avoid warnings later, setting itself up to not exit when the program
812 terminates, and defaulting to printing return values for the C<r> command.
816 # Needed for the statement after exec():
818 # This BEGIN block is simply used to switch off warnings during debugger
819 # compilation. Probably it would be better practice to fix the warnings,
820 # but this is how it's done at the moment.
825 } # Switch compilation warnings off until another BEGIN.
827 local ($^W) = 0; # Switch run-time warnings off during init.
829 =head2 THREADS SUPPORT
831 If we are running under a threaded Perl, we require threads and threads::shared
832 if the environment variable C<PERL5DB_THREADED> is set, to enable proper
833 threaded debugger control. C<-dt> can also be used to set this.
835 Each new thread will be announced and the debugger prompt will always inform
836 you of each new thread created. It will also indicate the thread id in which
837 we are currently running within the prompt like this:
841 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
842 command prompt. The prompt will show: C<[0]> when running under threads, but
843 not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
845 While running under threads, when you set or delete a breakpoint (etc.), this
846 will apply to all threads, not just the currently running one. When you are
847 in a currently executing thread, you will stay there until it completes. With
848 the current implementation it is not currently possible to hop from one thread
851 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
853 Note that threading support was built into the debugger as of Perl version
854 C<5.8.6> and debugger version C<1.2.8>.
859 # ensure we can share our non-threaded variables or no-op
860 if ($ENV{PERL5DB_THREADED}) {
862 require threads::shared;
863 import threads::shared qw(share);
867 print "Threads support enabled\n";
869 *share = sub(\[$@%]) {};
873 # These variables control the execution of 'dumpvar.pl'.
888 # used to control die() reporting in diesignal()
891 use vars qw($CarpLevel);
894 # without threads, $filename is not defined until DB::DB is called
895 share($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 our ($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,
1367 PERLDB_VISITED - files that had breakpoints
1368 PERLDB_FILE_... - breakpoints for a file
1369 PERLDB_OPT - active options
1370 PERLDB_INC - the original @INC
1371 PERLDB_PRETYPE - preprompt debugger actions
1372 PERLDB_PRE - preprompt Perl code
1373 PERLDB_POST - post-prompt Perl code
1374 PERLDB_TYPEAHEAD - typeahead captured by readline()
1376 We chug through all these variables and plug the values saved in them
1377 back into the appropriate spots in the debugger.
1381 use vars qw(%postponed_file @typeahead);
1383 our (@hist, @truehist);
1385 sub _restore_shared_globals_after_restart
1387 @hist = get_list('PERLDB_HIST');
1388 %break_on_load = get_list("PERLDB_ON_LOAD");
1389 %postponed = get_list("PERLDB_POSTPONE");
1393 share(%break_on_load);
1397 sub _restore_breakpoints_and_actions {
1399 my @had_breakpoints = get_list("PERLDB_VISITED");
1401 for my $file_idx ( 0 .. $#had_breakpoints ) {
1402 my $filename = $had_breakpoints[$file_idx];
1403 my %pf = get_list("PERLDB_FILE_$file_idx");
1404 $postponed_file{ $filename } = \%pf if %pf;
1405 my @lines = sort {$a <=> $b} keys(%pf);
1406 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1407 for my $line_idx (0 .. $#lines) {
1408 _set_breakpoint_enabled_status(
1411 ($enabled_statuses[$line_idx] ? 1 : ''),
1419 sub _restore_options_after_restart
1421 my %options_map = get_list("PERLDB_OPT");
1423 while ( my ( $opt, $val ) = each %options_map ) {
1424 $val =~ s/[\\\']/\\$1/g;
1425 parse_options("$opt'$val'");
1431 sub _restore_globals_after_restart
1433 # restore original @INC
1434 @INC = get_list("PERLDB_INC");
1437 # return pre/postprompt actions and typeahead buffer
1438 $pretype = [ get_list("PERLDB_PRETYPE") ];
1439 $pre = [ get_list("PERLDB_PRE") ];
1440 $post = [ get_list("PERLDB_POST") ];
1441 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1447 if ( exists $ENV{PERLDB_RESTART} ) {
1449 # We're restarting, so we don't need the flag that says to restart anymore.
1450 delete $ENV{PERLDB_RESTART};
1453 _restore_shared_globals_after_restart();
1455 _restore_breakpoints_and_actions();
1458 _restore_options_after_restart();
1460 _restore_globals_after_restart();
1461 } ## end if (exists $ENV{PERLDB_RESTART...
1463 =head2 SETTING UP THE TERMINAL
1465 Now, we'll decide how the debugger is going to interact with the user.
1466 If there's no TTY, we set the debugger to run non-stop; there's not going
1467 to be anyone there to enter commands.
1471 use vars qw($notty $console $tty $LINEINFO);
1472 use vars qw($lineinfo $doccmd);
1476 # Local autoflush to avoid rt#116769,
1477 # as calling IO::File methods causes an unresolvable loop
1478 # that results in debugger failure.
1480 my $o = select($_[0]);
1492 If there is a TTY, we have to determine who it belongs to before we can
1493 proceed. If this is a slave editor or graphical debugger (denoted by
1494 the first command-line switch being '-emacs'), we shift this off and
1495 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1501 # Is Perl being run from a slave editor or graphical debugger?
1502 # If so, don't use readline, and set $slave_editor = 1.
1503 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1508 #require Term::ReadLine;
1512 We then determine what the console should be on various systems:
1516 =item * Cygwin - We use C<stdin> instead of a separate device.
1520 if ( $^O eq 'cygwin' ) {
1522 # /dev/tty is binary. use stdin for textmode
1526 =item * Unix - use F</dev/tty>.
1530 elsif ( -e "/dev/tty" ) {
1531 $console = "/dev/tty";
1534 =item * Windows or MSDOS - use C<con>.
1538 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1542 =item * VMS - use C<sys$command>.
1548 # everything else is ...
1549 $console = "sys\$command";
1556 Several other systems don't use a specific console. We C<undef $console>
1557 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1558 with a slave editor).
1562 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1564 # /dev/tty is binary. use stdin for textmode
1568 if ( $^O eq 'NetWare' ) {
1570 # /dev/tty is binary. use stdin for textmode
1574 # In OS/2, we need to use STDIN to get textmode too, even though
1575 # it pretty much looks like Unix otherwise.
1576 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1583 If there is a TTY hanging around from a parent, we use that as the console.
1587 $console = $tty if defined $tty;
1589 =head2 SOCKET HANDLING
1591 The debugger is capable of opening a socket and carrying out a debugging
1592 session over the socket.
1594 If C<RemotePort> was defined in the options, the debugger assumes that it
1595 should try to start a debugging session on that port. It builds the socket
1596 and then tries to connect the input and output filehandles to it.
1600 # Handle socket stuff.
1602 if ( defined $remoteport ) {
1604 # If RemotePort was defined in the options, connect input and output
1606 $IN = $OUT = connect_remoteport();
1607 } ## end if (defined $remoteport)
1611 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1612 this is probably a situation where multiple debuggers are running (for example,
1613 a backticked command that starts up another debugger). We create a new IN and
1614 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1622 # Two debuggers running (probably a system or a backtick that invokes
1623 # the debugger itself under the running one). create a new IN and OUT
1624 # filehandle, and do the necessary mojo to create a new tty if we
1625 # know how, and we can.
1626 create_IN_OUT(4) if $CreateTTY & 4;
1629 # If we have a console, check to see if there are separate ins and
1630 # outs to open. (They are assumed identical if not.)
1632 my ( $i, $o ) = split /,/, $console;
1633 $o = $i unless defined $o;
1635 # read/write on in, or just read, or read on STDIN.
1637 || open( IN, "<$i" )
1638 || open( IN, "<&STDIN" );
1640 # read/write/create/clobber out, or write/create/clobber out,
1641 # or merge with STDERR, or merge with STDOUT.
1643 || open( OUT, ">$o" )
1644 || open( OUT, ">&STDERR" )
1645 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1647 } ## end if ($console)
1648 elsif ( not defined $console ) {
1650 # No console. Open STDIN.
1651 open( IN, "<&STDIN" );
1653 # merge with STDERR, or with STDOUT.
1654 open( OUT, ">&STDERR" )
1655 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1656 $console = 'STDIN/OUT';
1657 } ## end elsif (not defined $console)
1659 # Keep copies of the filehandles so that when the pager runs, it
1660 # can close standard input without clobbering ours.
1661 if ($console or (not defined($console))) {
1665 } ## end elsif (from if(defined $remoteport))
1667 # Unbuffer DB::OUT. We need to see responses right away.
1670 # Line info goes to debugger output unless pointed elsewhere.
1671 # Pointing elsewhere makes it possible for slave editors to
1672 # keep track of file and position. We have both a filehandle
1673 # and a I/O description to keep track of.
1674 $LINEINFO = $OUT unless defined $LINEINFO;
1675 $lineinfo = $console unless defined $lineinfo;
1676 # share($LINEINFO); # <- unable to share globs
1681 To finish initialization, we show the debugger greeting,
1682 and then call the C<afterinit()> subroutine if there is one.
1686 # Show the debugger greeting.
1687 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1688 unless ($runnonstop) {
1691 if ( $term_pid eq '-1' ) {
1692 print $OUT "\nDaughter DB session started...\n";
1695 print $OUT "\nLoading DB routines from $header\n";
1698 $slave_editor ? "enabled" : "available", ".\n"
1701 "\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
1702 } ## end else [ if ($term_pid eq '-1')
1703 } ## end unless ($runnonstop)
1704 } ## end else [ if ($notty)
1706 # XXX This looks like a bug to me.
1707 # Why copy to @ARGS and then futz with @args?
1710 # Make sure backslashes before single quotes are stripped out, and
1711 # keep args unless they are numeric (XXX why?)
1712 # s/\'/\\\'/g; # removed while not justified understandably
1713 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1716 # If there was an afterinit() sub defined, call it. It will get
1717 # executed in our scope, so it can fiddle with debugger globals.
1718 if ( defined &afterinit ) { # May be defined in $rcfile
1722 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1723 use vars qw($I_m_init);
1727 ############################################################ Subroutines
1733 This gigantic subroutine is the heart of the debugger. Called before every
1734 statement, its job is to determine if a breakpoint has been reached, and
1735 stop if so; read commands from the user, parse them, and execute
1736 them, and then send execution off to the next statement.
1738 Note that the order in which the commands are processed is very important;
1739 some commands earlier in the loop will actually alter the C<$cmd> variable
1740 to create other commands to be executed later. This is all highly I<optimized>
1741 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1742 see what's happening in any given command.
1746 # $cmd cannot be an our() variable unfortunately (possible perl bug?).
1776 sub _DB__determine_if_we_should_break
1778 # if we have something here, see if we should break.
1779 # $stop is lexical and local to this block - $action on the other hand
1784 && _is_breakpoint_enabled($filename, $line)
1785 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1788 # Stop if the stop criterion says to just stop.
1789 if ( $stop eq '1' ) {
1793 # It's a conditional stop; eval it in the user's context and
1794 # see if we should stop. If so, remove the one-time sigil.
1796 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1797 # The &-call is here to ascertain the mutability of @_.
1799 # If the breakpoint is temporary, then delete its enabled status.
1800 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1801 _cancel_breakpoint_temp_enabled_status($filename, $line);
1804 } ## end if ($dbline{$line} && ...
1807 sub _DB__is_finished {
1808 if ($finished and $level <= 1) {
1817 sub _DB__read_next_cmd
1821 # We have a terminal, or can get one ...
1826 # ... and it belongs to this PID or we get one for this PID ...
1827 if ($term_pid != $$) {
1831 # ... and we got a line of command input ...
1832 $cmd = DB::readline(
1833 "$pidprompt $tid DB"
1836 . ( '>' x $level ) . " "
1839 return defined($cmd);
1842 sub _DB__trim_command_and_return_first_component {
1845 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1846 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1848 my ($verb, $args) = $cmd =~ m{\A(\S*)\s*(.*)}s;
1850 $obj->cmd_verb($verb);
1851 $obj->cmd_args($args);
1856 sub _DB__handle_f_command {
1859 if ($file = $obj->cmd_args) {
1860 # help for no arguments (old-style was return from sub).
1863 "The old f command is now the r command.\n"; # hint
1864 print $OUT "The new f command switches filenames.\n";
1866 } ## end if (!$file)
1868 # if not in magic file list, try a close match.
1869 if ( !defined $main::{ '_<' . $file } ) {
1870 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
1872 $try = substr( $try, 2 );
1873 print $OUT "Choosing $try matching '$file':\n";
1876 } ## end if (($try) = grep(m#^_<.*$file#...
1877 } ## end if (!defined $main::{ ...
1879 # If not successfully switched now, we failed.
1880 if ( !defined $main::{ '_<' . $file } ) {
1881 print $OUT "No file matching '$file' is loaded.\n";
1885 # We switched, so switch the debugger internals around.
1886 elsif ( $file ne $filename ) {
1887 *dbline = $main::{ '_<' . $file };
1892 } ## end elsif ($file ne $filename)
1894 # We didn't switch; say we didn't.
1896 print $OUT "Already in $file.\n";
1904 sub _DB__handle_dot_command {
1908 if ($obj->_is_full('.')) {
1909 $incr = -1; # stay at current line
1911 # Reset everything to the old location.
1913 $filename = $filename_ini;
1914 *dbline = $main::{ '_<' . $filename };
1918 print_lineinfo($obj->position());
1925 sub _DB__handle_y_command {
1928 if (my ($match_level, $match_vars)
1929 = $obj->cmd_args =~ /\A(?:(\d*)\s*(.*))?\z/) {
1931 # See if we've got the necessary support.
1932 if (!eval { require PadWalker; PadWalker->VERSION(0.08) }) {
1936 ? "PadWalker module not found - please install\n"
1942 # Load up dumpvar if we don't have it. If we can, that is.
1943 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
1944 defined &main::dumpvar
1945 or print $OUT "dumpvar.pl not available.\n"
1948 # Got all the modules we need. Find them and print them.
1949 my @vars = split( ' ', $match_vars || '' );
1952 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 1 ) };
1954 # Oops. Can't find it.
1961 # Show the desired vars with dumplex().
1962 my $savout = select($OUT);
1964 # Have dumplex dump the lexicals.
1965 foreach my $key (sort keys %$h) {
1966 dumpvar::dumplex( $key, $h->{$key},
1967 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
1975 sub _DB__handle_c_command {
1978 my $i = $obj->cmd_args;
1980 if ($i =~ m#\A[\w:]*\z#) {
1982 # Hey, show's over. The debugged program finished
1983 # executing already.
1984 next CMD if _DB__is_finished();
1986 # Capture the place to put a one-time break.
1989 # Probably not needed, since we finish an interactive
1990 # sub-session anyway...
1991 # local $filename = $filename;
1992 # local *dbline = *dbline; # XXX Would this work?!
1994 # The above question wonders if localizing the alias
1995 # to the magic array works or not. Since it's commented
1996 # out, we'll just leave that to speculation for now.
1998 # If the "subname" isn't all digits, we'll assume it
1999 # is a subroutine name, and try to find it.
2000 if ( $subname =~ /\D/ ) { # subroutine name
2001 # Qualify it to the current package unless it's
2002 # already qualified.
2003 $subname = $package . "::" . $subname
2004 unless $subname =~ /::/;
2006 # find_sub will return "file:line_number" corresponding
2007 # to where the subroutine is defined; we call find_sub,
2008 # break up the return value, and assign it in one
2010 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2012 # Force the line number to be numeric.
2015 # If we got a line number, we found the sub.
2018 # Switch all the debugger's internals around so
2019 # we're actually working with that file.
2021 *dbline = $main::{ '_<' . $filename };
2023 # Mark that there's a breakpoint in this file.
2024 $had_breakpoints{$filename} |= 1;
2026 # Scan forward to the first executable line
2027 # after the 'sub whatever' line.
2030 while ($dbline[$_line_num] == 0 && $_line_num< $max)
2037 # We didn't find a sub by that name.
2039 print $OUT "Subroutine $subname not found.\n";
2042 } ## end if ($subname =~ /\D/)
2044 # At this point, either the subname was all digits (an
2045 # absolute line-break request) or we've scanned through
2046 # the code following the definition of the sub, looking
2047 # for an executable, which we may or may not have found.
2049 # If $i (which we set $subname from) is non-zero, we
2050 # got a request to break at some line somewhere. On
2051 # one hand, if there wasn't any real subroutine name
2052 # involved, this will be a request to break in the current
2053 # file at the specified line, so we have to check to make
2054 # sure that the line specified really is breakable.
2056 # On the other hand, if there was a subname supplied, the
2057 # preceding block has moved us to the proper file and
2058 # location within that file, and then scanned forward
2059 # looking for the next executable line. We have to make
2060 # sure that one was found.
2062 # On the gripping hand, we can't do anything unless the
2063 # current value of $i points to a valid breakable line.
2068 if ( $dbline[$i] == 0 ) {
2069 print $OUT "Line $i not breakable.\n";
2073 # Yes. Set up the one-time-break sigil.
2074 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2075 _enable_breakpoint_temp_enabled_status($filename, $i);
2078 # Turn off stack tracing from here up.
2079 for my $j (0 .. $stack_depth) {
2088 sub _DB__handle_forward_slash_command {
2091 # The pattern as a string.
2092 use vars qw($inpat);
2094 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2096 # Remove the final slash.
2097 $inpat =~ s:([^\\])/$:$1:;
2099 # If the pattern isn't null ...
2100 if ( $inpat ne "" ) {
2102 # Turn off warn and die processing for a bit.
2103 local $SIG{__DIE__};
2104 local $SIG{__WARN__};
2106 # Create the pattern.
2107 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2110 # Oops. Bad pattern. No biscuit.
2111 # Print the eval error and go back for more
2117 } ## end if ($inpat ne "")
2119 # Set up to stop on wrap-around.
2122 # Don't move off the current line.
2125 my $pat = $obj->pat;
2127 # Done in eval so nothing breaks if the pattern
2128 # does something weird.
2133 # Move ahead one line.
2136 # Wrap if we pass the last line.
2137 if ($start > $max) {
2141 # Stop if we have gotten back to this line again,
2142 last if ($start == $end);
2144 # A hit! (Note, though, that we are doing
2145 # case-insensitive matching. Maybe a qr//
2146 # expression would be better, so the user could
2147 # do case-sensitive matching if desired.
2148 if ($dbline[$start] =~ m/$pat/i) {
2149 if ($slave_editor) {
2150 # Handle proper escaping in the slave.
2151 print {$OUT} "\032\032$filename:$start:0\n";
2154 # Just print the line normally.
2155 print {$OUT} "$start:\t",$dbline[$start],"\n";
2157 # And quit since we found something.
2167 # If we wrapped, there never was a match.
2168 if ( $start == $end ) {
2169 print {$OUT} "/$pat/: not found\n";
2177 sub _DB__handle_question_mark_command {
2180 # ? - backward pattern search.
2181 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2183 # Get the pattern, remove trailing question mark.
2184 $inpat =~ s:([^\\])\?$:$1:;
2186 # If we've got one ...
2187 if ( $inpat ne "" ) {
2189 # Turn off die & warn handlers.
2190 local $SIG{__DIE__};
2191 local $SIG{__WARN__};
2192 eval '$inpat =~ m' . "\a$inpat\a";
2196 # Ouch. Not good. Print the error.
2201 } ## end if ($inpat ne "")
2203 # Where we are now is where to stop after wraparound.
2206 # Don't move away from this line.
2209 my $pat = $obj->pat;
2210 # Search inside the eval to prevent pattern badness
2218 # Wrap if we pass the first line.
2220 $start = $max if ($start <= 0);
2222 # Quit if we get back where we started,
2223 last if ($start == $end);
2226 if ($dbline[$start] =~ m/$pat/i) {
2227 if ($slave_editor) {
2228 # Yep, follow slave editor requirements.
2229 print $OUT "\032\032$filename:$start:0\n";
2232 # Yep, just print normally.
2233 print $OUT "$start:\t",$dbline[$start],"\n";
2242 # Say we failed if the loop never found anything,
2243 if ( $start == $end ) {
2244 print {$OUT} "?$pat?: not found\n";
2252 sub _DB__handle_restart_and_rerun_commands {
2255 my $cmd_cmd = $obj->cmd_verb;
2256 my $cmd_params = $obj->cmd_args;
2257 # R - restart execution.
2258 # rerun - controlled restart execution.
2259 if ($cmd_cmd eq 'rerun' or $cmd_params eq '') {
2260 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
2262 # Close all non-system fds for a clean restart. A more
2263 # correct method would be to close all fds that were not
2264 # open when the process started, but this seems to be
2265 # hard. See "debugger 'R'estart and open database
2266 # connections" on p5p.
2268 my $max_fd = 1024; # default if POSIX can't be loaded
2269 if (eval { require POSIX }) {
2270 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
2273 if (defined $max_fd) {
2274 foreach ($^F+1 .. $max_fd-1) {
2275 next unless open FD_TO_CLOSE, "<&=$_";
2280 # And run Perl again. We use exec() to keep the
2281 # PID stable (and that way $ini_pids is still valid).
2282 exec(@args) or print {$OUT} "exec failed: $!\n";
2290 sub _DB__handle_run_command_in_pager_command {
2293 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
2294 if ( $pager =~ /^\|/ ) {
2296 # Default pager is into a pipe. Redirect I/O.
2297 open( SAVEOUT, ">&STDOUT" )
2298 || _db_warn("Can't save STDOUT");
2299 open( STDOUT, ">&OUT" )
2300 || _db_warn("Can't redirect STDOUT");
2301 } ## end if ($pager =~ /^\|/)
2304 # Not into a pipe. STDOUT is safe.
2305 open( SAVEOUT, ">&OUT" ) || _db_warn("Can't save DB::OUT");
2308 # Fix up environment to record we have less if so.
2311 unless ( $obj->piped(scalar ( open( OUT, $pager ) ) ) ) {
2313 # Couldn't open pipe to pager.
2314 _db_warn("Can't pipe output to '$pager'");
2315 if ( $pager =~ /^\|/ ) {
2317 # Redirect I/O back again.
2318 open( OUT, ">&STDOUT" ) # XXX: lost message
2319 || _db_warn("Can't restore DB::OUT");
2320 open( STDOUT, ">&SAVEOUT" )
2321 || _db_warn("Can't restore STDOUT");
2323 } ## end if ($pager =~ /^\|/)
2326 # Redirect I/O. STDOUT already safe.
2327 open( OUT, ">&STDOUT" ) # XXX: lost message
2328 || _db_warn("Can't restore DB::OUT");
2331 } ## end unless ($piped = open(OUT,...
2333 # Set up broken-pipe handler if necessary.
2334 $SIG{PIPE} = \&DB::catch
2336 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
2339 # Save current filehandle, and put it back.
2340 $obj->selected(scalar( select(OUT) ));
2341 # Don't put it back if pager was a pipe.
2342 if ($cmd !~ /\A\|\|/)
2344 select($obj->selected());
2348 # Trim off the pipe symbols and run the command now.
2349 $cmd =~ s#\A\|+\s*##;
2356 sub _DB__handle_m_command {
2359 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2364 # m expr - set up DB::eval to do the work
2365 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2366 $onetimeDump = 'methods'; # method output gets used there
2372 sub _DB__at_end_of_every_command {
2375 # At the end of every command:
2378 # Unhook the pipe mechanism now.
2379 if ( $pager =~ /^\|/ ) {
2381 # No error from the child.
2384 # we cannot warn here: the handle is missing --tchrist
2385 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
2387 # most of the $? crud was coping with broken cshisms
2388 # $? is explicitly set to 0, so this never runs.
2390 print SAVEOUT "Pager '$pager' failed: ";
2392 print SAVEOUT "shell returned -1\n";
2395 print SAVEOUT ( $? & 127 )
2396 ? " (SIG#" . ( $? & 127 ) . ")"
2397 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
2400 print SAVEOUT "status ", ( $? >> 8 ), "\n";
2404 # Reopen filehandle for our output (if we can) and
2405 # restore STDOUT (if we can).
2406 open( OUT, ">&STDOUT" ) || _db_warn("Can't restore DB::OUT");
2407 open( STDOUT, ">&SAVEOUT" )
2408 || _db_warn("Can't restore STDOUT");
2410 # Turn off pipe exception handler if necessary.
2411 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
2413 # Will stop ignoring SIGPIPE if done like nohup(1)
2414 # does SIGINT but Perl doesn't give us a choice.
2415 } ## end if ($pager =~ /^\|/)
2418 # Non-piped "pager". Just restore STDOUT.
2419 open( OUT, ">&SAVEOUT" ) || _db_warn("Can't restore DB::OUT");
2422 # Close filehandle pager was using, restore the normal one
2426 if ($obj->selected() ne "") {
2427 select($obj->selected);
2433 } ## end if ($piped)
2438 sub _DB__handle_watch_expressions
2442 if ( $DB::trace & 2 ) {
2443 for my $n (0 .. $#DB::to_watch) {
2444 $DB::evalarg = $DB::to_watch[$n];
2445 local $DB::onetimeDump; # Tell DB::eval() to not output results
2447 # Fix context DB::eval() wants to return an array, but
2448 # we need a scalar here.
2449 my ($val) = join( "', '", DB::eval(@_) );
2450 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
2453 if ( $val ne $DB::old_watch[$n] ) {
2455 # Yep! Show the difference, and fake an interrupt.
2457 print {$DB::OUT} <<EOP;
2458 Watchpoint $n:\t$DB::to_watch[$n] changed:
2459 old value:\t$DB::old_watch[$n]
2462 $DB::old_watch[$n] = $val;
2463 } ## end if ($val ne $old_watch...
2464 } ## end for my $n (0 ..
2465 } ## end if ($trace & 2)
2472 # 'v' is the value (i.e: method name or subroutine ref).
2473 # 's' is subroutine.
2476 '-' => { t => 'm', v => '_handle_dash_command', },
2477 '.' => { t => 's', v => \&_DB__handle_dot_command, },
2478 '=' => { t => 'm', v => '_handle_equal_sign_command', },
2479 'H' => { t => 'm', v => '_handle_H_command', },
2480 'S' => { t => 'm', v => '_handle_S_command', },
2481 'T' => { t => 'm', v => '_handle_T_command', },
2482 'W' => { t => 'm', v => '_handle_W_command', },
2483 'c' => { t => 's', v => \&_DB__handle_c_command, },
2484 'f' => { t => 's', v => \&_DB__handle_f_command, },
2485 'm' => { t => 's', v => \&_DB__handle_m_command, },
2486 'n' => { t => 'm', v => '_handle_n_command', },
2487 'p' => { t => 'm', v => '_handle_p_command', },
2488 'q' => { t => 'm', v => '_handle_q_command', },
2489 'r' => { t => 'm', v => '_handle_r_command', },
2490 's' => { t => 'm', v => '_handle_s_command', },
2491 'save' => { t => 'm', v => '_handle_save_command', },
2492 'source' => { t => 'm', v => '_handle_source_command', },
2493 't' => { t => 'm', v => '_handle_t_command', },
2494 'w' => { t => 'm', v => '_handle_w_command', },
2495 'x' => { t => 'm', v => '_handle_x_command', },
2496 'y' => { t => 's', v => \&_DB__handle_y_command, },
2497 (map { $_ => { t => 'm', v => '_handle_V_command_and_X_command', }, }
2499 (map { $_ => { t => 'm', v => '_handle_enable_disable_commands', }, }
2500 qw(enable disable)),
2502 { t => 's', v => \&_DB__handle_restart_and_rerun_commands, },
2504 (map { $_ => {t => 'm', v => '_handle_cmd_wrapper_commands' }, }
2505 qw(a A b B e E h i l L M o O v w W)),
2510 # lock the debugger and get the thread id for the prompt
2514 my ($prefix, $after, $infix);
2520 if ($ENV{PERL5DB_THREADED}) {
2521 $tid = eval { "[".threads->tid."]" };
2527 my $obj = DB::Obj->new(
2529 position => \$position,
2532 explicit_stop => \$explicit_stop,
2534 cmd_args => \$cmd_args,
2535 cmd_verb => \$cmd_verb,
2538 selected => \$selected,
2542 $obj->_DB_on_init__initialize_globals(@_);
2544 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
2545 # The code being debugged may have altered them.
2548 # Since DB::DB gets called after every line, we can use caller() to
2549 # figure out where we last were executing. Sneaky, eh? This works because
2550 # caller is returning all the extra information when called from the
2552 local ( $package, $filename, $line ) = caller;
2553 $filename_ini = $filename;
2555 # set up the context for DB::eval, so it can properly execute
2556 # code on behalf of the user. We add the package in so that the
2557 # code is eval'ed in the proper package (not in the debugger!).
2558 local $usercontext = _calc_usercontext($package);
2560 # Create an alias to the active file magical array to simplify
2562 local (*dbline) = $main::{ '_<' . $filename };
2564 # Last line in the program.
2567 # The &-call is here to ascertain the mutability of @_.
2568 &_DB__determine_if_we_should_break;
2570 # Preserve the current stop-or-not, and see if any of the W
2571 # (watch expressions) has changed.
2572 my $was_signal = $signal;
2574 # If we have any watch expressions ...
2575 _DB__handle_watch_expressions($obj);
2577 =head2 C<watchfunction()>
2579 C<watchfunction()> is a function that can be defined by the user; it is a
2580 function which will be run on each entry to C<DB::DB>; it gets the
2581 current package, filename, and line as its parameters.
2583 The watchfunction can do anything it likes; it is executing in the
2584 debugger's context, so it has access to all of the debugger's internal
2585 data structures and functions.
2587 C<watchfunction()> can control the debugger's actions. Any of the following
2588 will cause the debugger to return control to the user's program after
2589 C<watchfunction()> executes:
2595 Returning a false value from the C<watchfunction()> itself.
2599 Altering C<$single> to a false value.
2603 Altering C<$signal> to a false value.
2607 Turning off the C<4> bit in C<$trace> (this also disables the
2608 check for C<watchfunction()>. This can be done with
2616 # If there's a user-defined DB::watchfunction, call it with the
2617 # current package, filename, and line. The function executes in
2619 if ( $trace & 4 ) { # User-installed watch
2621 if watchfunction( $package, $filename, $line )
2624 and not( $trace & ~4 );
2625 } ## end if ($trace & 4)
2627 # Pick up any alteration to $signal in the watchfunction, and
2628 # turn off the signal now.
2629 $was_signal = $signal;
2632 =head2 GETTING READY TO EXECUTE COMMANDS
2634 The debugger decides to take control if single-step mode is on, the
2635 C<t> command was entered, or the user generated a signal. If the program
2636 has fallen off the end, we set things up so that entering further commands
2637 won't cause trouble, and we say that the program is over.
2641 # Make sure that we always print if asked for explicitly regardless
2642 # of $trace_to_depth .
2643 $explicit_stop = ($single || $was_signal);
2645 # Check to see if we should grab control ($single true,
2646 # trace set appropriately, or we got a signal).
2647 if ( $explicit_stop || ( $trace & 1 ) ) {
2648 $obj->_DB__grab_control(@_);
2649 } ## end if ($single || ($trace...
2653 If there's an action to be executed for the line we stopped at, execute it.
2654 If there are any preprompt actions, execute those as well.
2658 # If there's an action, do it now.
2661 # The &-call is here to ascertain the mutability of @_.
2665 # Are we nested another level (e.g., did we evaluate a function
2666 # that had a breakpoint in it at the debugger prompt)?
2667 if ( $single || $was_signal ) {
2669 # Yes, go down a level.
2670 local $level = $level + 1;
2672 # Do any pre-prompt actions.
2673 foreach $evalarg (@$pre) {
2674 # The &-call is here to ascertain the mutability of @_.
2678 # Complain about too much recursion if we passed the limit.
2680 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2683 # The line we're currently on. Set $incr to -1 to stay here
2684 # until we get a command that tells us to advance.
2686 $incr = -1; # for backward motion.
2688 # Tack preprompt debugger actions ahead of any actual input.
2689 @typeahead = ( @$pretype, @typeahead );
2691 =head2 WHERE ARE WE?
2693 XXX Relocate this section?
2695 The debugger normally shows the line corresponding to the current line of
2696 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2697 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2699 C<$incr> controls by how many lines the I<current> line should move forward
2700 after a command is executed. If set to -1, this indicates that the I<current>
2701 line shouldn't change.
2703 C<$start> is the I<current> line. It is used for things like knowing where to
2704 move forwards or backwards from when doing an C<L> or C<-> command.
2706 C<$max> tells the debugger where the last line of the current file is. It's
2707 used to terminate loops most often.
2709 =head2 THE COMMAND LOOP
2711 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2718 The outer part of the loop, starting at the C<CMD> label. This loop
2719 reads a command and then executes it.
2723 The inner part of the loop, starting at the C<PIPE> label. This part
2724 is wholly contained inside the C<CMD> block and only executes a command.
2725 Used to handle commands running inside a pager.
2729 So why have two labels to restart the loop? Because sometimes, it's easier to
2730 have a command I<generate> another command and then re-execute the loop to do
2731 the new command. This is faster, but perhaps a bit more convoluted.
2735 # The big command dispatch loop. It keeps running until the
2736 # user yields up control again.
2738 # If we have a terminal for input, and we get something back
2739 # from readline(), keep on processing.
2742 while (_DB__read_next_cmd($tid))
2746 # ... try to execute the input as debugger commands.
2748 # Don't stop running.
2751 # No signal is active.
2754 # Handle continued commands (ending with \):
2755 if ($cmd =~ s/\\\z/\n/) {
2756 $cmd .= DB::readline(" cont: ");
2760 =head4 The null command
2762 A newline entered by itself means I<re-execute the last command>. We grab the
2763 command out of C<$laststep> (where it was recorded previously), and copy it
2764 back into C<$cmd> to be executed below. If there wasn't any previous command,
2765 we'll do nothing below (no command will match). If there was, we also save it
2766 in the command history and fall through to allow the command parsing to pick
2771 # Empty input means repeat the last command.
2775 chomp($cmd); # get rid of the annoying extra newline
2776 if (length($cmd) >= 2) {
2777 push( @hist, $cmd );
2779 push( @truehist, $cmd );
2783 # This is a restart point for commands that didn't arrive
2784 # via direct user input. It allows us to 'redo PIPE' to
2785 # re-execute command processing without reading a new command.
2787 _DB__trim_command_and_return_first_component($obj);
2789 =head3 COMMAND ALIASES
2791 The debugger can create aliases for commands (these are stored in the
2792 C<%alias> hash). Before a command is executed, the command loop looks it up
2793 in the alias hash and substitutes the contents of the alias for the command,
2794 completely replacing it.
2798 # See if there's an alias for the command, and set it up if so.
2799 if ( $alias{$cmd_verb} ) {
2801 # Squelch signal handling; we want to keep control here
2802 # if something goes loco during the alias eval.
2803 local $SIG{__DIE__};
2804 local $SIG{__WARN__};
2806 # This is a command, so we eval it in the DEBUGGER's
2807 # scope! Otherwise, we can't see the special debugger
2808 # variables, or get to the debugger's subs. (Well, we
2809 # _could_, but why make it even more complicated?)
2810 eval "\$cmd =~ $alias{$cmd_verb}";
2813 print $OUT "Couldn't evaluate '$cmd_verb' alias: $@";
2816 _DB__trim_command_and_return_first_component($obj);
2817 } ## end if ($alias{$cmd_verb})
2819 =head3 MAIN-LINE COMMANDS
2821 All of these commands work up to and after the program being debugged has
2826 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2827 try to execute further, cleaning any restart-related stuff out of the
2828 environment, and executing with the last value of C<$?>.
2832 # All of these commands were remapped in perl 5.8.0;
2833 # we send them off to the secondary dispatcher (see below).
2834 $obj->_handle_special_char_cmd_wrapper_commands;
2835 _DB__trim_command_and_return_first_component($obj);
2837 if (my $cmd_rec = $cmd_lookup{$cmd_verb}) {
2838 my $type = $cmd_rec->{t};
2839 my $val = $cmd_rec->{v};
2843 elsif ($type eq 's') {
2848 =head4 C<t> - trace [n]
2850 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2851 If level is specified, set C<$trace_to_depth>.
2853 =head4 C<S> - list subroutines matching/not matching a pattern
2855 Walks through C<%sub>, checking to see whether or not to print the name.
2857 =head4 C<X> - list variables in current package
2859 Since the C<V> command actually processes this, just change this to the
2860 appropriate C<V> command and fall through.
2862 =head4 C<V> - list variables
2864 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2866 =head4 C<x> - evaluate and print an expression
2868 Hands the expression off to C<DB::eval>, setting it up to print the value
2869 via C<dumpvar.pl> instead of just printing it directly.
2871 =head4 C<m> - print methods
2873 Just uses C<DB::methods> to determine what methods are available.
2875 =head4 C<f> - switch files
2877 Switch to a different filename.
2879 =head4 C<.> - return to last-executed line.
2881 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2882 and then we look up the line in the magical C<%dbline> hash.
2884 =head4 C<-> - back one window
2886 We change C<$start> to be one window back; if we go back past the first line,
2887 we set it to be the first line. We ser C<$incr> to put us back at the
2888 currently-executing line, and then put a C<l $start +> (list one window from
2889 C<$start>) in C<$cmd> to be executed later.
2891 =head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
2893 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2894 problems, most notably that the default case of several commands destroying
2895 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2896 retain the old commands for those who were used to using them or who preferred
2897 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2898 deal with them instead of processing them in-line.
2900 =head4 C<y> - List lexicals in higher scope
2902 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2903 above the current one and then displays then using C<dumpvar.pl>.
2905 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2907 All of the commands below this point don't work after the program being
2908 debugged has ended. All of them check to see if the program has ended; this
2909 allows the commands to be relocated without worrying about a 'line of
2910 demarcation' above which commands can be entered anytime, and below which
2913 =head4 C<n> - single step, but don't trace down into subs
2915 Done by setting C<$single> to 2, which forces subs to execute straight through
2916 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2917 so a null command knows what to re-execute.
2919 =head4 C<s> - single-step, entering subs
2921 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2922 subs. Also saves C<s> as C<$lastcmd>.
2924 =head4 C<c> - run continuously, setting an optional breakpoint
2926 Most of the code for this command is taken up with locating the optional
2927 breakpoint, which is either a subroutine name or a line number. We set
2928 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2929 in this and all call levels above this one.
2931 =head4 C<r> - return from a subroutine
2933 For C<r> to work properly, the debugger has to stop execution again
2934 immediately after the return is executed. This is done by forcing
2935 single-stepping to be on in the call level above the current one. If
2936 we are printing return values when a C<r> is executed, set C<$doret>
2937 appropriately, and force us out of the command loop.
2939 =head4 C<T> - stack trace
2941 Just calls C<DB::print_trace>.
2943 =head4 C<w> - List window around current line.
2945 Just calls C<DB::cmd_w>.
2947 =head4 C<W> - watch-expression processing.
2949 Just calls C<DB::cmd_W>.
2951 =head4 C</> - search forward for a string in the source
2953 We take the argument and treat it as a pattern. If it turns out to be a
2954 bad one, we return the error we got from trying to C<eval> it and exit.
2955 If not, we create some code to do the search and C<eval> it so it can't
2960 _DB__handle_forward_slash_command($obj);
2962 =head4 C<?> - search backward for a string in the source
2964 Same as for C</>, except the loop runs backwards.
2968 _DB__handle_question_mark_command($obj);
2970 =head4 C<$rc> - Recall command
2972 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2973 that the terminal supports history). It finds the command required, puts it
2974 into C<$cmd>, and redoes the loop to execute it.
2978 # $rc - recall command.
2979 $obj->_handle_rc_recall_command;
2981 =head4 C<$sh$sh> - C<system()> command
2983 Calls the C<_db_system()> to handle the command. This keeps the C<STDIN> and
2984 C<STDOUT> from getting messed up.
2988 $obj->_handle_sh_command;
2990 =head4 C<$rc I<pattern> $rc> - Search command history
2992 Another command to manipulate C<@hist>: this one searches it with a pattern.
2993 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
2997 $obj->_handle_rc_search_history_command;
2999 =head4 C<$sh> - Invoke a shell
3001 Uses C<_db_system()> to invoke a shell.
3005 =head4 C<$sh I<command>> - Force execution of a command in a shell
3007 Like the above, but the command is passed to the shell. Again, we use
3008 C<_db_system()> to avoid problems with C<STDIN> and C<STDOUT>.
3010 =head4 C<H> - display commands in history
3012 Prints the contents of C<@hist> (if any).
3014 =head4 C<man, doc, perldoc> - look up documentation
3016 Just calls C<runman()> to print the appropriate document.
3020 $obj->_handle_doc_command;
3024 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3025 the bottom of the loop.
3027 =head4 C<=> - define command alias
3029 Manipulates C<%alias> to add or list command aliases.
3031 =head4 C<source> - read commands from a file.
3033 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3036 =head4 C<enable> C<disable> - enable or disable breakpoints
3038 This enables or disables breakpoints.
3040 =head4 C<save> - send current history to a file
3042 Takes the complete history, (not the shrunken version you see with C<H>),
3043 and saves it to the given filename, so it can be replayed using C<source>.
3045 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3047 =head4 C<R> - restart
3049 Restart the debugger session.
3051 =head4 C<rerun> - rerun the current session
3053 Return to any given position in the B<true>-history list
3055 =head4 C<|, ||> - pipe output through the pager.
3057 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3058 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3059 pipe to the pager (restoring the output filehandles if this fails). If this
3060 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3061 set C<$signal>, sending us back into the debugger.
3063 We then trim off the pipe symbols and C<redo> the command loop at the
3064 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3069 # || - run command in the pager, with output to DB::OUT.
3070 _DB__handle_run_command_in_pager_command($obj);
3072 =head3 END OF COMMAND PARSING
3074 Anything left in C<$cmd> at this point is a Perl expression that we want to
3075 evaluate. We'll always evaluate in the user's context, and fully qualify
3076 any variables we might want to address in the C<DB> package.
3082 # trace an expression
3083 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3085 # Make sure the flag that says "the debugger's running" is
3086 # still on, to make sure we get control again.
3087 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3089 # Run *our* eval that executes in the caller's context.
3090 # The &-call is here to ascertain the mutability of @_.
3093 # Turn off the one-time-dump stuff now.
3095 $onetimeDump = undef;
3096 $onetimedumpDepth = undef;
3098 elsif ( $term_pid == $$ ) {
3099 eval { # May run under miniperl, when not available...
3104 # XXX If this is the master pid, print a newline.
3107 } ## end while (($term || &setterm...
3109 =head3 POST-COMMAND PROCESSING
3111 After each command, we check to see if the command output was piped anywhere.
3112 If so, we go through the necessary code to unhook the pipe and go back to
3113 our standard filehandles for input and output.
3118 _DB__at_end_of_every_command($obj);
3121 =head3 COMMAND LOOP TERMINATION
3123 When commands have finished executing, we come here. If the user closed the
3124 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3125 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3126 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3127 The interpreter will then execute the next line and then return control to us
3132 # No more commands? Quit.
3133 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
3135 # Evaluate post-prompt commands.
3136 foreach $evalarg (@$post) {
3137 # The &-call is here to ascertain the mutability of @_.
3140 } # if ($single || $signal)
3142 # Put the user's globals back where you found them.
3143 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3147 # Because DB::Obj is used above,
3149 # my $obj = DB::Obj->new(
3151 # The following package declaration must come before that,
3152 # or else runtime errors will occur with
3154 # PERLDB_OPTS="autotrace nonstop"
3164 my $self = bless {}, $class;
3172 my ($self, $args) = @_;
3174 %{$self} = (%$self, %$args);
3181 foreach my $slot_name (qw(
3182 after explicit_stop infix pat piped position prefix selected cmd_verb
3185 my $slot = $slot_name;
3190 ${ $self->{$slot} } = shift;
3193 return ${ $self->{$slot} };
3196 *{"append_to_$slot"} = sub {
3200 return $self->$slot($self->$slot . $s);
3205 sub _DB_on_init__initialize_globals
3209 # Check for whether we should be running continuously or not.
3210 # _After_ the perl program is compiled, $single is set to 1:
3211 if ( $single and not $second_time++ ) {
3213 # Options say run non-stop. Run until we get an interrupt.
3214 if ($runnonstop) { # Disable until signal
3215 # If there's any call stack in place, turn off single
3216 # stepping into subs throughout the stack.
3217 for my $i (0 .. $stack_depth) {
3221 # And we are now no longer in single-step mode.
3224 # If we simply returned at this point, we wouldn't get
3225 # the trace info. Fall on through.
3227 } ## end if ($runnonstop)
3229 elsif ($ImmediateStop) {
3231 # We are supposed to stop here; XXX probably a break.
3232 $ImmediateStop = 0; # We've processed it; turn it off
3233 $signal = 1; # Simulate an interrupt to force
3234 # us into the command loop
3236 } ## end if ($single and not $second_time...
3238 # If we're in single-step mode, or an interrupt (real or fake)
3239 # has occurred, turn off non-stop mode.
3240 $runnonstop = 0 if $single or $signal;
3245 sub _my_print_lineinfo
3247 my ($self, $i, $incr_pos) = @_;
3250 # Print it indented if tracing is on.
3251 DB::print_lineinfo( ' ' x $stack_depth,
3252 "$i:\t$DB::dbline[$i]" . $self->after );
3255 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3260 return $DB::dbline[$line];
3264 my ($self, $letter) = @_;
3266 return ($DB::cmd eq $letter);
3269 sub _DB__grab_control
3273 # Yes, grab control.
3274 if ($slave_editor) {
3276 # Tell the editor to update its position.
3277 $self->position("\032\032${DB::filename}:$line:0\n");
3278 DB::print_lineinfo($self->position());
3283 Special check: if we're in package C<DB::fake>, we've gone through the
3284 C<END> block at least once. We set up everything so that we can continue
3285 to enter commands and have a valid context to be in.
3289 elsif ( $DB::package eq 'DB::fake' ) {
3291 # Fallen off the end already.
3296 DB::print_help(<<EOP);
3297 Debugged program terminated. Use B<q> to quit or B<R> to restart,
3298 use B<o> I<inhibit_exit> to avoid stopping after program termination,
3299 B<h q>, B<h R> or B<h o> to get additional info.
3302 # Set the DB::eval context appropriately.
3303 $DB::package = 'main';
3304 $DB::usercontext = DB::_calc_usercontext($DB::package);
3305 } ## end elsif ($package eq 'DB::fake')
3309 If the program hasn't finished executing, we scan forward to the
3310 next executable line, print that out, build the prompt from the file and line
3311 number information, and print that.
3318 # Still somewhere in the midst of execution. Set up the
3320 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3321 # Perl 5 ones (sorry, we don't print Klingon
3324 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
3325 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
3326 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
3328 # Break up the prompt if it's really long.
3329 if ( length($self->prefix()) > 30 ) {
3330 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
3332 $self->infix(":\t");
3335 $self->infix("):\t");
3337 $self->prefix . $line. $self->infix
3338 . $self->_curr_line . $self->after
3342 # Print current line info, indenting if necessary.
3343 $self->_my_print_lineinfo($line, $self->position);
3346 my $line_i = sub { return $DB::dbline[$i]; };
3348 # Scan forward, stopping at either the end or the next
3350 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
3353 # Drop out on null statements, block closers, and comments.
3354 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
3356 # Drop out if the user interrupted us.
3359 # Append a newline if the line doesn't have one. Can happen
3360 # in eval'ed text, for instance.
3361 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
3363 # Next executable line.
3364 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
3366 $self->append_to_position($incr_pos);
3367 $self->_my_print_lineinfo($i, $incr_pos);
3368 } ## end for ($i = $line + 1 ; $i...
3369 } ## end else [ if ($slave_editor)
3374 sub _handle_t_command {
3377 my $levels = $self->cmd_args();
3379 if ((!length($levels)) or ($levels !~ /\D/)) {
3382 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
3383 print {$OUT} "Trace = "
3385 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3394 sub _handle_S_command {
3397 if (my ($print_all_subs, $should_reverse, $Spatt)
3398 = $self->cmd_args =~ /\A((!)?(.+))?\z/) {
3399 # $Spatt is the pattern (if any) to use.
3401 my $Srev = defined $should_reverse;
3402 # No args - print all subs.
3403 my $Snocheck = !defined $print_all_subs;
3405 # Need to make these sane here.
3409 # Search through the debugger's magical hash of subs.
3410 # If $nocheck is true, just print the sub name.
3411 # Otherwise, check it against the pattern. We then use
3412 # the XOR trick to reverse the condition as required.
3413 foreach $subname ( sort( keys %sub ) ) {
3414 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
3415 print $OUT $subname, "\n";
3424 sub _handle_V_command_and_X_command {
3427 $DB::cmd =~ s/^X\b/V $DB::package/;
3429 # Bare V commands get the currently-being-debugged package
3431 if ($self->_is_full('V')) {
3432 $DB::cmd = "V $DB::package";
3435 # V - show variables in package.
3436 if (my ($new_packname, $new_vars_str) =
3437 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
3439 # Save the currently selected filehandle and
3440 # force output to debugger's filehandle (dumpvar
3441 # just does "print" for output).
3442 my $savout = select($OUT);
3444 # Grab package name and variables to dump.
3445 $packname = $new_packname;
3446 my @vars = split( ' ', $new_vars_str );
3448 # If main::dumpvar isn't here, get it.
3449 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
3450 if ( defined &main::dumpvar ) {
3452 # We got it. Turn off subroutine entry/exit messages
3453 # for the moment, along with return values.
3457 # must detect sigpipe failures - not catching
3458 # then will cause the debugger to die.
3462 defined $option{dumpDepth}
3463 ? $option{dumpDepth}
3464 : -1, # assume -1 unless specified
3469 # The die doesn't need to include the $@, because
3470 # it will automatically get propagated for us.
3472 die unless $@ =~ /dumpvar print failed/;
3474 } ## end if (defined &main::dumpvar)
3477 # Couldn't load dumpvar.
3478 print $OUT "dumpvar.pl not available.\n";
3481 # Restore the output filehandle, and go round again.
3489 sub _handle_dash_command {
3492 if ($self->_is_full('-')) {
3494 # back up by a window; go to 1 if back too far.
3495 $start -= $incr + $window + 1;
3496 $start = 1 if $start <= 0;
3497 $incr = $window - 1;
3499 # Generate and execute a "l +" command (handled below).
3500 $DB::cmd = 'l ' . ($start) . '+';
3506 sub _n_or_s_commands_generic {
3507 my ($self, $new_val) = @_;
3509 next CMD if DB::_DB__is_finished();
3511 # Single step, but don't enter subs.
3514 # Save for empty command (repeat last).
3515 $laststep = $DB::cmd;
3520 my ($self, $letter, $new_val) = @_;
3522 if ($self->_is_full($letter)) {
3523 $self->_n_or_s_commands_generic($new_val);
3526 $self->_n_or_s_and_arg_commands_generic($letter, $new_val);
3532 sub _handle_n_command {
3535 return $self->_n_or_s('n', 2);
3538 sub _handle_s_command {
3541 return $self->_n_or_s('s', 1);
3544 sub _handle_r_command {
3547 # r - return from the current subroutine.
3548 if ($self->_is_full('r')) {
3550 # Can't do anything if the program's over.
3551 next CMD if DB::_DB__is_finished();
3553 # Turn on stack trace.
3554 $stack[$stack_depth] |= 1;
3556 # Print return value unless the stack is empty.
3557 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
3564 sub _handle_T_command {
3567 if ($self->_is_full('T')) {
3568 DB::print_trace( $OUT, 1 ); # skip DB
3575 sub _handle_w_command {
3578 DB::cmd_w( 'w', $self->cmd_args() );
3584 sub _handle_W_command {
3587 if (my $arg = $self->cmd_args) {
3588 DB::cmd_W( 'W', $arg );
3595 sub _handle_rc_recall_command {
3598 # $rc - recall command.
3599 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
3601 # No arguments, take one thing off history.
3602 pop(@hist) if length($DB::cmd) > 1;
3604 # Relative (- found)?
3605 # Y - index back from most recent (by 1 if bare minus)
3606 # N - go to that particular command slot or the last
3607 # thing if nothing following.
3610 scalar($minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist ))
3613 # Pick out the command desired.
3614 $DB::cmd = $hist[$self->cmd_verb];
3616 # Print the command to be executed and restart the loop
3617 # with that command in the buffer.
3618 print {$OUT} $DB::cmd, "\n";
3625 sub _handle_rc_search_history_command {
3628 # $rc pattern $rc - find a command in the history.
3629 if (my ($arg) = $DB::cmd =~ /\A$rc([^$rc].*)\z/) {
3631 # Create the pattern to use.
3635 # Toss off last entry if length is >1 (and it always is).
3636 pop(@hist) if length($DB::cmd) > 1;
3640 # Look backward through the history.
3642 for ( $i = $#hist ; $i ; --$i ) {
3643 # Stop if we find it.
3644 last SEARCH_HIST if $hist[$i] =~ /$pat/;
3650 print $OUT "No such command!\n\n";
3654 # Found it. Put it in the buffer, print it, and process it.
3655 $DB::cmd = $hist[$i];
3656 print $OUT $DB::cmd, "\n";
3663 sub _handle_H_command {
3666 if ($self->cmd_args =~ m#\A\*#) {
3667 @hist = @truehist = ();
3668 print $OUT "History cleansed\n";
3672 if (my ($num) = $self->cmd_args =~ /\A(?:-(\d+))?/) {
3674 # Anything other than negative numbers is ignored by
3675 # the (incorrect) pattern, so this test does nothing.
3676 $end = $num ? ( $#hist - $num ) : 0;
3678 # Set to the minimum if less than zero.
3679 $hist = 0 if $hist < 0;
3681 # Start at the end of the array.
3682 # Stay in while we're still above the ending value.
3683 # Tick back by one each time around the loop.
3686 for ( $i = $#hist ; $i > $end ; $i-- ) {
3688 # Print the command unless it has no arguments.
3689 print $OUT "$i: ", $hist[$i], "\n"
3690 unless $hist[$i] =~ /^.?$/;
3699 sub _handle_doc_command {
3702 # man, perldoc, doc - show manual pages.
3704 = $DB::cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
3705 DB::runman($man_page);
3712 sub _handle_p_command {
3715 my $print_cmd = 'print {$DB::OUT} ';
3716 # p - print (no args): print $_.
3717 if ($self->_is_full('p')) {
3718 $DB::cmd = $print_cmd . '$_';
3721 # p - print the given expression.
3722 $DB::cmd =~ s/\Ap\b/$print_cmd /;
3728 sub _handle_equal_sign_command {
3731 if ($DB::cmd =~ s/\A=\s*//) {
3733 if ( length $DB::cmd == 0 ) {
3735 # No args, get current aliases.
3736 @keys = sort keys %alias;
3738 elsif ( my ( $k, $v ) = ( $DB::cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3740 # Creating a new alias. $k is alias name, $v is
3743 # can't use $_ or kill //g state
3744 for my $x ( $k, $v ) {
3746 # Escape "alarm" characters.
3750 # Substitute key for value, using alarm chars
3751 # as separators (which is why we escaped them in
3753 $alias{$k} = "s\a$k\a$v\a";
3755 # Turn off standard warn and die behavior.
3756 local $SIG{__DIE__};
3757 local $SIG{__WARN__};
3760 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3762 # Nope. Bad alias. Say so and get out.
3763 print $OUT "Can't alias $k to $v: $@\n";
3768 # We'll only list the new one.
3770 } ## end elsif (my ($k, $v) = ($DB::cmd...
3772 # The argument is the alias to list.
3780 # Messy metaquoting: Trim the substitution code off.
3781 # We use control-G as the delimiter because it's not
3782 # likely to appear in the alias.
3783 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3786 print $OUT "$k\t= $1\n";
3788 elsif ( defined $alias{$k} ) {
3790 # Couldn't trim it off; just print the alias code.
3791 print $OUT "$k\t$alias{$k}\n";
3796 print "No alias for $k\n";
3798 } ## end for my $k (@keys)
3805 sub _handle_source_command {
3808 # source - read commands from a file (or pipe!) and execute.
3809 if (my $sourced_fn = $self->cmd_args) {
3810 if ( open my $fh, $sourced_fn ) {
3812 # Opened OK; stick it in the list of file handles.
3818 DB::_db_warn("Can't execute '$sourced_fn': $!\n");
3826 sub _handle_enable_disable_commands {
3829 my $which_cmd = $self->cmd_verb;
3830 my $position = $self->cmd_args;
3832 if ($position !~ /\s/) {
3833 my ($fn, $line_num);
3834 if ($position =~ m{\A\d+\z})
3836 $fn = $DB::filename;
3837 $line_num = $position;
3839 elsif (my ($new_fn, $new_line_num)
3840 = $position =~ m{\A(.*):(\d+)\z}) {
3841 ($fn, $line_num) = ($new_fn, $new_line_num);
3845 DB::_db_warn("Wrong spec for enable/disable argument.\n");
3849 if (DB::_has_breakpoint_data_ref($fn, $line_num)) {
3850 DB::_set_breakpoint_enabled_status($fn, $line_num,
3851 ($which_cmd eq 'enable' ? 1 : '')
3855 DB::_db_warn("No breakpoint set at ${fn}:${line_num}\n");
3865 sub _handle_save_command {
3868 if (my $new_fn = $self->cmd_args) {
3869 my $filename = $new_fn || '.perl5dbrc'; # default?
3870 if ( open my $fh, '>', $filename ) {
3872 # chomp to remove extraneous newlines from source'd files
3873 chomp( my @truelist =
3874 map { m/\A\s*(save|source)/ ? "#$_" : $_ }
3876 print {$fh} join( "\n", @truelist );
3877 print "commands saved in $filename\n";
3880 DB::_db_warn("Can't save debugger commands in '$new_fn': $!\n");
3888 sub _n_or_s_and_arg_commands_generic {
3889 my ($self, $letter, $new_val) = @_;
3891 # s - single-step. Remember the last command was 's'.
3892 if ($DB::cmd =~ s#\A\Q$letter\E\s#\$DB::single = $new_val;\n#) {
3893 $laststep = $letter;
3899 sub _handle_sh_command {
3902 # $sh$sh - run a shell command (if it's all ASCII).
3903 # Can't run shell commands with Unicode in the debugger, hmm.
3904 my $my_cmd = $DB::cmd;
3905 if ($my_cmd =~ m#\A$sh#gms) {
3907 if ($my_cmd =~ m#\G\z#cgms) {
3908 # Run the user's shell. If none defined, run Bourne.
3909 # We resume execution when the shell terminates.
3910 DB::_db_system( $ENV{SHELL} || "/bin/sh" );
3913 elsif ($my_cmd =~ m#\G$sh\s*(.*)#cgms) {
3918 elsif ($my_cmd =~ m#\G\s*(.*)#cgms) {
3919 DB::_db_system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3925 sub _handle_x_command {
3928 if ($DB::cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
3929 $onetimeDump = 'dump'; # main::dumpvar shows the output
3931 # handle special "x 3 blah" syntax XXX propagate
3932 # doc back to special variables.
3933 if ( $DB::cmd =~ s#\A\s*(\d+)(?=\s)# #) {
3934 $onetimedumpDepth = $1;
3941 sub _handle_q_command {
3944 if ($self->_is_full('q')) {
3953 sub _handle_cmd_wrapper_commands {
3956 DB::cmd_wrapper( $self->cmd_verb, $self->cmd_args, $line );
3960 sub _handle_special_char_cmd_wrapper_commands {
3963 # All of these commands were remapped in perl 5.8.0;
3964 # we send them off to the secondary dispatcher (see below).
3965 if (my ($cmd_letter, $my_arg) = $DB::cmd =~ /\A([<>\{]{1,2})\s*(.*)/so) {
3966 DB::cmd_wrapper( $cmd_letter, $my_arg, $line );
3977 # The following code may be executed now:
3982 C<sub> is called whenever a subroutine call happens in the program being
3983 debugged. The variable C<$DB::sub> contains the name of the subroutine
3986 The core function of this subroutine is to actually call the sub in the proper
3987 context, capturing its output. This of course causes C<DB::DB> to get called
3988 again, repeating until the subroutine ends and returns control to C<DB::sub>
3989 again. Once control returns, C<DB::sub> figures out whether or not to dump the
3990 return value, and returns its captured copy of the return value as its own
3991 return value. The value then feeds back into the program being debugged as if
3992 C<DB::sub> hadn't been there at all.
3994 C<sub> does all the work of printing the subroutine entry and exit messages
3995 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3996 and also prints the return value if needed (for the C<r> command and if
3997 the 16 bit is set in C<$frame>).
3999 It also tracks the subroutine call depth by saving the current setting of
4000 C<$single> in the C<@stack> package global; if this exceeds the value in
4001 C<$deep>, C<sub> automatically turns on printing of the current depth by
4002 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
4003 of stop/don't stop on entry to subs set as it currently is set.
4005 =head3 C<caller()> support
4007 If C<caller()> is called from the package C<DB>, it provides some
4008 additional data, in the following order:
4014 The package name the sub was in
4016 =item * C<$filename>
4018 The filename it was defined in
4022 The line number it was defined on
4024 =item * C<$subroutine>
4026 The subroutine name; C<(eval)> if an C<eval>().
4030 1 if it has arguments, 0 if not
4032 =item * C<$wantarray>
4034 1 if array context, 0 if scalar context
4036 =item * C<$evaltext>
4038 The C<eval>() text, if any (undefined for C<eval BLOCK>)
4040 =item * C<$is_require>
4042 frame was created by a C<use> or C<require> statement
4046 pragma information; subject to change between versions
4050 pragma information; subject to change between versions
4052 =item * C<@DB::args>
4054 arguments with which the subroutine was invoked
4062 # We need to fully qualify the name ("DB::sub") to make "use strict;"
4063 # happy. -- Shlomi Fish
4065 sub _indent_print_line_info {
4066 my ($offset, $str) = @_;
4068 print_lineinfo( ' ' x ($stack_depth - $offset), $str);
4073 sub _print_frame_message {
4077 if ($frame & 4) { # Extended frame entry message
4078 _indent_print_line_info(-1, "in ");
4080 # Why -1? But it works! :-(
4081 # Because print_trace will call add 1 to it and then call
4082 # dump_trace; this results in our skipping -1+1 = 0 stack frames
4085 # Now it's 0 because we extracted a function.
4086 print_trace( $LINEINFO, 0, 1, 1, "$sub$al" );
4089 _indent_print_line_info(-1, "entering $sub$al\n" );
4097 # lock ourselves under threads
4100 # Whether or not the autoloader was running, a scalar to put the
4101 # sub's return value in (if needed), and an array to put the sub's
4102 # return value in (if needed).
4103 my ( $al, $ret, @ret ) = "";
4104 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) {
4105 print "creating new thread\n";
4108 # If the last ten characters are '::AUTOLOAD', note we've traced
4109 # into AUTOLOAD for $sub.
4110 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
4112 $al = " for $$sub" if defined $$sub;
4115 # We stack the stack pointer and then increment it to protect us
4116 # from a situation that might unwind a whole bunch of call frames
4117 # at once. Localizing the stack pointer means that it will automatically
4118 # unwind the same amount when multiple stack frames are unwound.
4119 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
4122 $#stack = $stack_depth;
4124 # Save current single-step setting.
4125 $stack[-1] = $single;
4127 # Turn off all flags except single-stepping.
4130 # If we've gotten really deeply recursed, turn on the flag that will
4131 # make us stop with the 'deep recursion' message.
4132 $single |= 4 if $stack_depth == $deep;
4134 # If frame messages are on ...
4136 _print_frame_message($al);
4137 # standard frame entry message
4139 my $print_exit_msg = sub {
4140 # Check for exit trace messages...
4143 if ($frame & 4) # Extended exit message
4145 _indent_print_line_info(0, "out ");
4146 print_trace( $LINEINFO, 0, 1, 1, "$sub$al" );
4150 _indent_print_line_info(0, "exited $sub$al\n" );
4156 # Determine the sub's return type, and capture appropriately.
4159 # Called in array context. call sub and capture output.
4160 # DB::DB will recursively get control again if appropriate; we'll come
4161 # back here when the sub is finished.
4167 # Pop the single-step value back off the stack.
4168 $single |= $stack[ $stack_depth-- ];
4170 $print_exit_msg->();
4172 # Print the return info if we need to.
4173 if ( $doret eq $stack_depth or $frame & 16 ) {
4175 # Turn off output record separator.
4177 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4179 # Indent if we're printing because of $frame tracing.
4182 print {$fh} ' ' x $stack_depth;
4185 # Print the return value.
4186 print {$fh} "list context return from $sub:\n";
4187 dumpit( $fh, \@ret );
4189 # And don't print it again.
4191 } ## end if ($doret eq $stack_depth...
4192 # And we have to return the return value now.
4194 } ## end if (wantarray)
4198 if ( defined wantarray ) {
4200 # Save the value if it's wanted at all.
4205 # Void return, explicitly.
4210 # Pop the single-step value off the stack.
4211 $single |= $stack[ $stack_depth-- ];
4213 # If we're doing exit messages...
4214 $print_exit_msg->();
4216 # If we are supposed to show the return value... same as before.
4217 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
4219 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4220 print $fh ( ' ' x $stack_depth ) if $frame & 16;
4223 ? "scalar context return from $sub: "
4224 : "void context return from $sub\n"
4226 dumpit( $fh, $ret ) if defined wantarray;
4228 } ## end if ($doret eq $stack_depth...
4230 # Return the appropriate scalar value.
4232 } ## end else [ if (wantarray)
4239 # lock ourselves under threads
4242 # Whether or not the autoloader was running, a scalar to put the
4243 # sub's return value in (if needed), and an array to put the sub's
4244 # return value in (if needed).
4245 my ( $al, $ret, @ret ) = "";
4246 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
4247 print "creating new thread\n";
4250 # If the last ten characters are C'::AUTOLOAD', note we've traced
4251 # into AUTOLOAD for $sub.
4252 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
4256 # We stack the stack pointer and then increment it to protect us
4257 # from a situation that might unwind a whole bunch of call frames
4258 # at once. Localizing the stack pointer means that it will automatically
4259 # unwind the same amount when multiple stack frames are unwound.
4260 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
4263 $#stack = $stack_depth;
4265 # Save current single-step setting.
4266 $stack[-1] = $single;
4268 # Turn off all flags except single-stepping.
4269 # Use local so the single-step value is popped back off the
4271 local $single = $single & 1;
4273 # If we've gotten really deeply recursed, turn on the flag that will
4274 # make us stop with the 'deep recursion' message.
4275 $single |= 4 if $stack_depth == $deep;
4277 # If frame messages are on ...
4278 _print_frame_message($al);
4280 # call the original lvalue sub.
4284 # Abstracting common code from multiple places elsewhere:
4285 sub depth_print_lineinfo {
4286 my $always_print = shift;
4288 print_lineinfo( @_ ) if ($always_print or $stack_depth < $trace_to_depth);
4291 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
4293 In Perl 5.8.0, there was a major realignment of the commands and what they did,
4294 Most of the changes were to systematize the command structure and to eliminate
4295 commands that threw away user input without checking.
4297 The following sections describe the code added to make it easy to support
4298 multiple command sets with conflicting command names. This section is a start
4299 at unifying all command processing to make it simpler to develop commands.
4301 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
4302 number, and C<$dbline> (the current line) as arguments.
4304 Support functions in this section which have multiple modes of failure C<die>
4305 on error; the rest simply return a false value.
4307 The user-interface functions (all of the C<cmd_*> functions) just output
4312 The C<%set> hash defines the mapping from command letter to subroutine
4315 C<%set> is a two-level hash, indexed by set name and then by command name.
4316 Note that trying to set the CommandSet to C<foobar> simply results in the
4317 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
4326 'A' => 'pre580_null',
4328 'B' => 'pre580_null',
4329 'd' => 'pre580_null',
4332 'M' => 'pre580_null',
4334 'o' => 'pre580_null',
4340 '<' => 'pre590_prepost',
4341 '<<' => 'pre590_prepost',
4342 '>' => 'pre590_prepost',
4343 '>>' => 'pre590_prepost',
4344 '{' => 'pre590_prepost',
4345 '{{' => 'pre590_prepost',
4349 my %breakpoints_data;
4351 sub _has_breakpoint_data_ref {
4352 my ($filename, $line) = @_;
4355 exists( $breakpoints_data{$filename} )
4357 exists( $breakpoints_data{$filename}{$line} )
4361 sub _get_breakpoint_data_ref {
4362 my ($filename, $line) = @_;
4364 return ($breakpoints_data{$filename}{$line} ||= +{});
4367 sub _delete_breakpoint_data_ref {
4368 my ($filename, $line) = @_;
4370 delete($breakpoints_data{$filename}{$line});
4371 if (! scalar(keys( %{$breakpoints_data{$filename}} )) ) {
4372 delete($breakpoints_data{$filename});
4378 sub _set_breakpoint_enabled_status {
4379 my ($filename, $line, $status) = @_;
4381 _get_breakpoint_data_ref($filename, $line)->{'enabled'} =
4388 sub _enable_breakpoint_temp_enabled_status {
4389 my ($filename, $line) = @_;
4391 _get_breakpoint_data_ref($filename, $line)->{'temp_enabled'} = 1;
4396 sub _cancel_breakpoint_temp_enabled_status {
4397 my ($filename, $line) = @_;
4399 my $ref = _get_breakpoint_data_ref($filename, $line);
4401 delete ($ref->{'temp_enabled'});
4404 _delete_breakpoint_data_ref($filename, $line);
4410 sub _is_breakpoint_enabled {
4411 my ($filename, $line) = @_;
4413 my $data_ref = _get_breakpoint_data_ref($filename, $line);
4414 return ($data_ref->{'enabled'} || $data_ref->{'temp_enabled'});
4417 =head2 C<cmd_wrapper()> (API)
4419 C<cmd_wrapper()> allows the debugger to switch command sets
4420 depending on the value of the C<CommandSet> option.
4422 It tries to look up the command in the C<%set> package-level I<lexical>
4423 (which means external entities can't fiddle with it) and create the name of
4424 the sub to call based on the value found in the hash (if it's there). I<All>
4425 of the commands to be handled in a set have to be added to C<%set>; if they
4426 aren't found, the 5.8.0 equivalent is called (if there is one).
4428 This code uses symbolic references.
4435 my $dblineno = shift;
4437 # Assemble the command subroutine's name by looking up the
4438 # command set and command name in %set. If we can't find it,
4439 # default to the older version of the command.
4441 . ( $set{$CommandSet}{$cmd}
4442 || ( $cmd =~ /\A[<>{]+/o ? 'prepost' : $cmd ) );
4444 # Call the command subroutine, call it by name.
4445 return __PACKAGE__->can($call)->( $cmd, $line, $dblineno );
4446 } ## end sub cmd_wrapper
4448 =head3 C<cmd_a> (command)
4450 The C<a> command handles pre-execution actions. These are associated with a
4451 particular line, so they're stored in C<%dbline>. We default to the current
4452 line if none is specified.
4458 my $line = shift || ''; # [.|line] expr
4461 # If it's dot (here), or not all digits, use the current line.
4462 $line =~ s/\A\./$dbline/;
4464 # Should be a line number followed by an expression.
4465 if ( my ($lineno, $expr) = $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
4467 if (! length($lineno)) {
4471 # If we have an expression ...
4472 if ( length $expr ) {
4474 # ... but the line isn't breakable, complain.
4475 if ( $dbline[$lineno] == 0 ) {
4477 "Line $lineno($dbline[$lineno]) does not have an action?\n";
4481 # It's executable. Record that the line has an action.
4482 $had_breakpoints{$filename} |= 2;
4484 # Remove any action, temp breakpoint, etc.
4485 $dbline{$lineno} =~ s/\0[^\0]*//;
4487 # Add the action to the line.
4488 $dbline{$lineno} .= "\0" . action($expr);
4490 _set_breakpoint_enabled_status($filename, $lineno, 1);
4492 } ## end if (length $expr)
4493 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
4498 "Adding an action requires an optional lineno and an expression\n"
4503 =head3 C<cmd_A> (command)
4505 Delete actions. Similar to above, except the delete code is in a separate
4506 subroutine, C<delete_action>.
4512 my $line = shift || '';
4516 $line =~ s/^\./$dbline/;
4518 # Call delete_action with a null param to delete them all.
4519 # The '1' forces the eval to be true. It'll be false only
4520 # if delete_action blows up for some reason, in which case
4521 # we print $@ and get out.
4522 if ( $line eq '*' ) {
4523 if (! eval { _delete_all_actions(); 1 }) {
4529 # There's a real line number. Pass it to delete_action.
4530 # Error trapping is as above.
4531 elsif ( $line =~ /^(\S.*)/ ) {
4532 if (! eval { delete_action($1); 1 }) {
4538 # Swing and a miss. Bad syntax.
4541 "Deleting an action requires a line number, or '*' for all\n" ; # hint
4545 =head3 C<delete_action> (API)
4547 C<delete_action> accepts either a line number or C<undef>. If a line number
4548 is specified, we check for the line being executable (if it's not, it
4549 couldn't have had an action). If it is, we just take the action off (this
4550 will get any kind of an action, including breakpoints).
4554 sub _remove_action_from_dbline {
4557 $dbline{$i} =~ s/\0[^\0]*//; # \^a
4558 delete $dbline{$i} if $dbline{$i} eq '';
4563 sub _delete_all_actions {
4564 print {$OUT} "Deleting all actions...\n";
4566 for my $file ( keys %had_breakpoints ) {
4567 local *dbline = $main::{ '_<' . $file };
4570 for my $i (1 .. $max) {
4571 if ( defined $dbline{$i} ) {
4572 _remove_action_from_dbline($i);
4576 unless ( $had_breakpoints{$file} &= ~2 ) {
4577 delete $had_breakpoints{$file};
4587 if ( defined($i) ) {
4589 die "Line $i has no action .\n" if $dbline[$i] == 0;
4591 # Nuke whatever's there.
4592 _remove_action_from_dbline($i);
4595 _delete_all_actions();
4599 =head3 C<cmd_b> (command)
4601 Set breakpoints. Since breakpoints can be set in so many places, in so many
4602 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4603 we try to parse the command type, and then shuttle it off to an appropriate
4604 subroutine to actually do the work of setting the breakpoint in the right
4611 my $line = shift; # [.|line] [cond]
4614 my $default_cond = sub {
4616 return length($cond) ? $cond : '1';
4619 # Make . the current line number if it's there..
4620 $line =~ s/^\.(\s|\z)/$dbline$1/;
4622 # No line number, no condition. Simple break on current line.
4623 if ( $line =~ /^\s*$/ ) {
4624 cmd_b_line( $dbline, 1 );
4627 # Break on load for a file.
4628 elsif ( my ($file) = $line =~ /^load\b\s*(.*)/ ) {
4633 # b compile|postpone <some sub> [<condition>]
4634 # The interpreter actually traps this one for us; we just put the
4635 # necessary condition in the %postponed hash.
4636 elsif ( my ($action, $subname, $cond)
4637 = $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4639 # De-Perl4-ify the name - ' separators to ::.
4640 $subname =~ s/'/::/g;
4642 # Qualify it into the current package unless it's already qualified.
4643 $subname = "${package}::" . $subname unless $subname =~ /::/;
4645 # Add main if it starts with ::.
4646 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4648 # Save the break type for this sub.
4649 $postponed{$subname} = (($action eq 'postpone')
4650 ? ( "break +0 if " . $default_cond->($cond) )
4652 } ## end elsif ($line =~ ...
4653 # b <filename>:<line> [<condition>]
4654 elsif (my ($filename, $line_num, $cond)
4655 = $line =~ /\A(\S+[^:]):(\d+)\s*(.*)/ms) {
4656 cmd_b_filename_line(
4659 (length($cond) ? $cond : '1'),
4662 # b <sub name> [<condition>]
4663 elsif ( my ($new_subname, $new_cond) =
4664 $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4667 $subname = $new_subname;
4668 cmd_b_sub( $subname, $default_cond->($new_cond) );
4671 # b <line> [<condition>].
4672 elsif ( my ($line_n, $cond) = $line =~ /^(\d*)\s*(.*)/ ) {
4674 # Capture the line. If none, it's the current line.
4675 $line = $line_n || $dbline;
4678 cmd_b_line( $line, $default_cond->($cond) );
4681 # Line didn't make sense.
4683 print "confused by line($line)?\n";
4689 =head3 C<break_on_load> (API)
4691 We want to break when this file is loaded. Mark this file in the
4692 C<%break_on_load> hash, and note that it has a breakpoint in
4693 C<%had_breakpoints>.
4699 $break_on_load{$file} = 1;
4700 $had_breakpoints{$file} |= 1;
4703 =head3 C<report_break_on_load> (API)
4705 Gives us an array of filenames that are set to break on load. Note that
4706 only files with break-on-load are in here, so simply showing the keys
4711 sub report_break_on_load {
4712 sort keys %break_on_load;
4715 =head3 C<cmd_b_load> (command)
4717 We take the file passed in and try to find it in C<%INC> (which maps modules
4718 to files they came from). We mark those files for break-on-load via
4719 C<break_on_load> and then report that it was done.
4727 # This is a block because that way we can use a redo inside it
4728 # even without there being any looping structure at all outside it.
4731 # Save short name and full path if found.
4733 push @files, $::INC{$file} if $::INC{$file};
4735 # Tack on .pm and do it again unless there was a '.' in the name
4737 $file .= '.pm', redo unless $file =~ /\./;
4740 # Do the real work here.
4741 break_on_load($_) for @files;
4743 # All the files that have break-on-load breakpoints.
4744 @files = report_break_on_load;
4746 # Normalize for the purposes of our printing this.
4749 print $OUT "Will stop on load of '@files'.\n";
4750 } ## end sub cmd_b_load
4752 =head3 C<$filename_error> (API package global)
4754 Several of the functions we need to implement in the API need to work both
4755 on the current file and on other files. We don't want to duplicate code, so
4756 C<$filename_error> is used to contain the name of the file that's being
4757 worked on (if it's not the current one).
4759 We can now build functions in pairs: the basic function works on the current
4760 file, and uses C<$filename_error> as part of its error message. Since this is
4761 initialized to C<"">, no filename will appear when we are working on the
4764 The second function is a wrapper which does the following:
4770 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4774 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4778 Calls the first function.
4780 The first function works on the I<current> file (i.e., the one we changed to),
4781 and prints C<$filename_error> in the error message (the name of the other file)
4782 if it needs to. When the functions return, C<*dbline> is restored to point
4783 to the actual current file (the one we're executing in) and
4784 C<$filename_error> is restored to C<"">. This restores everything to
4785 the way it was before the second function was called at all.
4787 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4794 use vars qw($filename_error);
4795 $filename_error = '';
4797 =head3 breakable_line(from, to) (API)
4799 The subroutine decides whether or not a line in the current file is breakable.
4800 It walks through C<@dbline> within the range of lines specified, looking for
4801 the first line that is breakable.
4803 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4804 first line I<after> C<$to> that's breakable, if there is one.
4806 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4807 first line I<before> C<$to> that's breakable, if there is one.
4811 sub breakable_line {
4813 my ( $from, $to ) = @_;
4815 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4818 # If there are at least 2 arguments, we're trying to search a range.
4821 # $delta is positive for a forward search, negative for a backward one.
4822 my $delta = $from < $to ? +1 : -1;
4824 # Keep us from running off the ends of the file.
4825 my $limit = $delta > 0 ? $#dbline : 1;
4827 # Clever test. If you're a mathematician, it's obvious why this
4828 # test works. If not:
4829 # If $delta is positive (going forward), $limit will be $#dbline.
4830 # If $to is less than $limit, ($limit - $to) will be positive, times
4831 # $delta of 1 (positive), so the result is > 0 and we should use $to
4832 # as the stopping point.
4834 # If $to is greater than $limit, ($limit - $to) is negative,
4835 # times $delta of 1 (positive), so the result is < 0 and we should
4836 # use $limit ($#dbline) as the stopping point.
4838 # If $delta is negative (going backward), $limit will be 1.
4839 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4840 # (negative) so the result is > 0, and we use $to as the stopping
4843 # If $to is less than zero, ($limit - $to) will be positive,
4844 # times $delta of -1 (negative), so the result is not > 0, and
4845 # we use $limit (1) as the stopping point.
4847 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4848 # (negative), still giving zero; the result is not > 0, and
4849 # we use $limit (1) as the stopping point.
4851 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4852 # (negative), giving a positive (>0) value, so we'll set $limit to
4855 $limit = $to if ( $limit - $to ) * $delta > 0;
4857 # The real search loop.
4858 # $i starts at $from (the point we want to start searching from).
4859 # We move through @dbline in the appropriate direction (determined
4860 # by $delta: either -1 (back) or +1 (ahead).
4861 # We stay in as long as we haven't hit an executable line
4862 # ($dbline[$i] == 0 means not executable) and we haven't reached
4863 # the limit yet (test similar to the above).
4864 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4866 } ## end if (@_ >= 2)
4868 # If $i points to a line that is executable, return that.
4869 return $i unless $dbline[$i] == 0;
4871 # Format the message and print it: no breakable lines in range.
4872 my ( $pl, $upto ) = ( '', '' );
4873 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4875 # If there's a filename in filename_error, we'll see it.
4877 die "Line$pl $from$upto$filename_error not breakable\n";
4878 } ## end sub breakable_line
4880 =head3 breakable_line_in_filename(file, from, to) (API)
4882 Like C<breakable_line>, but look in another file.
4886 sub breakable_line_in_filename {
4888 # Capture the file name.
4891 # Swap the magic line array over there temporarily.
4892 local *dbline = $main::{ '_<' . $f };
4894 # If there's an error, it's in this other file.
4895 local $filename_error = " of '$f'";
4897 # Find the breakable line.
4900 # *dbline and $filename_error get restored when this block ends.
4902 } ## end sub breakable_line_in_filename
4904 =head3 break_on_line(lineno, [condition]) (API)
4906 Adds a breakpoint with the specified condition (or 1 if no condition was
4907 specified) to the specified line. Dies if it can't.
4913 my $cond = @_ ? shift(@_) : 1;
4919 # Woops, not a breakable line. $filename_error allows us to say
4920 # if it was in a different file.
4921 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4923 # Mark this file as having breakpoints in it.
4924 $had_breakpoints{$filename} |= 1;
4926 # If there is an action or condition here already ...
4927 if ( $dbline{$i} ) {
4929 # ... swap this condition for the existing one.
4930 $dbline{$i} =~ s/^[^\0]*/$cond/;
4934 # Nothing here - just add the condition.
4935 $dbline{$i} = $cond;
4937 _set_breakpoint_enabled_status($filename, $i, 1);
4941 } ## end sub break_on_line
4943 =head3 cmd_b_line(line, [condition]) (command)
4945 Wrapper for C<break_on_line>. Prints the failure message if it
4951 if (not eval { break_on_line(@_); 1 }) {
4953 print $OUT $@ and return;
4957 } ## end sub cmd_b_line
4959 =head3 cmd_b_filename_line(line, [condition]) (command)
4961 Wrapper for C<break_on_filename_line>. Prints the failure message if it
4966 sub cmd_b_filename_line {
4967 if (not eval { break_on_filename_line(@_); 1 }) {
4969 print $OUT $@ and return;
4975 =head3 break_on_filename_line(file, line, [condition]) (API)
4977 Switches to the file specified and then calls C<break_on_line> to set
4982 sub break_on_filename_line {
4985 my $cond = @_ ? shift(@_) : 1;
4987 # Switch the magical hash temporarily.
4988 local *dbline = $main::{ '_<' . $f };
4990 # Localize the variables that break_on_line uses to make its message.
4991 local $filename_error = " of '$f'";
4992 local $filename = $f;
4994 # Add the breakpoint.
4995 break_on_line( $i, $cond );
4998 } ## end sub break_on_filename_line
5000 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
5002 Switch to another file, search the range of lines specified for an
5003 executable one, and put a breakpoint on the first one you find.
5007 sub break_on_filename_line_range {
5011 my $cond = @_ ? shift(@_) : 1;
5013 # Find a breakable line if there is one.
5014 my $i = breakable_line_in_filename( $f, $from, $to );
5016 # Add the breakpoint.
5017 break_on_filename_line( $f, $i, $cond );
5020 } ## end sub break_on_filename_line_range
5022 =head3 subroutine_filename_lines(subname, [condition]) (API)
5024 Search for a subroutine within a given file. The condition is ignored.
5025 Uses C<find_sub> to locate the desired subroutine.
5029 sub subroutine_filename_lines {
5030 my ( $subname ) = @_;
5032 # Returned value from find_sub() is fullpathname:startline-endline.
5033 # The match creates the list (fullpathname, start, end).
5034 return (find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/);
5035 } ## end sub subroutine_filename_lines
5037 =head3 break_subroutine(subname) (API)
5039 Places a break on the first line possible in the specified subroutine. Uses
5040 C<subroutine_filename_lines> to find the subroutine, and
5041 C<break_on_filename_line_range> to place the break.
5045 sub break_subroutine {
5046 my $subname = shift;
5048 # Get filename, start, and end.
5049 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
5050 or die "Subroutine $subname not found.\n";
5053 # Null condition changes to '1' (always true).
5054 my $cond = @_ ? shift(@_) : 1;
5056 # Put a break the first place possible in the range of lines
5057 # that make up this subroutine.
5058 break_on_filename_line_range( $file, $s, $e, $cond );
5061 } ## end sub break_subroutine
5063 =head3 cmd_b_sub(subname, [condition]) (command)
5065 We take the incoming subroutine name and fully-qualify it as best we can.
5069 =item 1. If it's already fully-qualified, leave it alone.
5071 =item 2. Try putting it in the current package.
5073 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
5075 =item 4. If it starts with '::', put it in 'main::'.
5079 After all this cleanup, we call C<break_subroutine> to try to set the
5085 my $subname = shift;
5086 my $cond = @_ ? shift : 1;
5088 # If the subname isn't a code reference, qualify it so that
5089 # break_subroutine() will work right.
5090 if ( ref($subname) ne 'CODE' ) {
5093 $subname =~ s/'/::/g;
5096 # Put it in this package unless it's already qualified.
5097 if ($subname !~ /::/)
5099 $subname = $package . '::' . $subname;
5102 # Requalify it into CORE::GLOBAL if qualifying it into this
5103 # package resulted in its not being defined, but only do so
5104 # if it really is in CORE::GLOBAL.
5105 my $core_name = "CORE::GLOBAL::$s";
5106 if ((!defined(&$subname))
5108 and (defined &{$core_name}))
5110 $subname = $core_name;
5113 # Put it in package 'main' if it has a leading ::.
5114 if ($subname =~ /\A::/)
5116 $subname = "main" . $subname;
5118 } ## end if ( ref($subname) ne 'CODE' ) {
5120 # Try to set the breakpoint.
5121 if (not eval { break_subroutine( $subname, $cond ); 1 }) {
5128 } ## end sub cmd_b_sub
5130 =head3 C<cmd_B> - delete breakpoint(s) (command)
5132 The command mostly parses the command line and tries to turn the argument
5133 into a line spec. If it can't, it uses the current line. It then calls
5134 C<delete_breakpoint> to actually do the work.
5136 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
5137 thereby deleting all the breakpoints.
5144 # No line spec? Use dbline.
5145 # If there is one, use it if it's non-zero, or wipe it out if it is.
5146 my $line = ( $_[0] =~ /\A\./ ) ? $dbline : (shift || '');
5149 # If the line was dot, make the line the current one.
5150 $line =~ s/^\./$dbline/;
5152 # If it's * we're deleting all the breakpoints.
5153 if ( $line eq '*' ) {
5154 if (not eval { delete_breakpoint(); 1 }) {
5159 # If there is a line spec, delete the breakpoint on that line.
5160 elsif ( $line =~ /\A(\S.*)/ ) {
5161 if (not eval { delete_breakpoint( $line || $dbline ); 1 }) {
5165 } ## end elsif ($line =~ /^(\S.*)/)
5170 "Deleting a breakpoint requires a line number, or '*' for all\n"
5177 =head3 delete_breakpoint([line]) (API)
5179 This actually does the work of deleting either a single breakpoint, or all
5182 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
5183 just drop out with a message saying so. If it is, we remove the condition
5184 part of the 'condition\0action' that says there's a breakpoint here. If,
5185 after we've done that, there's nothing left, we delete the corresponding
5186 line in C<%dbline> to signal that no action needs to be taken for this line.
5188 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
5189 which lists all currently-loaded files which have breakpoints. We then look
5190 at each line in each of these files, temporarily switching the C<%dbline>
5191 and C<@dbline> structures to point to the files in question, and do what
5192 we did in the single line case: delete the condition in C<@dbline>, and
5193 delete the key in C<%dbline> if nothing's left.
5195 We then wholesale delete C<%postponed>, C<%postponed_file>, and
5196 C<%break_on_load>, because these structures contain breakpoints for files
5197 and code that haven't been loaded yet. We can just kill these off because there
5198 are no magical debugger structures associated with them.
5202 sub _remove_breakpoint_entry {
5206 _delete_breakpoint_data_ref($fn, $i);
5211 sub _delete_all_breakpoints {
5212 print {$OUT} "Deleting all breakpoints...\n";
5214 # %had_breakpoints lists every file that had at least one
5216 for my $fn ( keys %had_breakpoints ) {
5218 # Switch to the desired file temporarily.
5219 local *dbline = $main::{ '_<' . $fn };
5223 # For all lines in this file ...
5224 for my $i (1 .. $max) {
5226 # If there's a breakpoint or action on this line ...
5227 if ( defined $dbline{$i} ) {
5229 # ... remove the breakpoint.
5230 $dbline{$i} =~ s/\A[^\0]+//;
5231 if ( $dbline{$i} =~ s/\A\0?\z// ) {
5232 # Remove the entry altogether if no action is there.
5233 _remove_breakpoint_entry($fn, $i);
5235 } ## end if (defined $dbline{$i...
5236 } ## end for $i (1 .. $max)
5238 # If, after we turn off the "there were breakpoints in this file"
5239 # bit, the entry in %had_breakpoints for this file is zero,
5240 # we should remove this file from the hash.
5241 if ( not $had_breakpoints{$fn} &= (~1) ) {
5242 delete $had_breakpoints{$fn};
5244 } ## end for my $fn (keys %had_breakpoints)
5246 # Kill off all the other breakpoints that are waiting for files that
5247 # haven't been loaded yet.
5249 undef %postponed_file;
5250 undef %break_on_load;
5255 sub _delete_breakpoint_from_line {
5258 # Woops. This line wasn't breakable at all.
5259 die "Line $i not breakable.\n" if $dbline[$i] == 0;
5261 # Kill the condition, but leave any action.
5262 $dbline{$i} =~ s/\A[^\0]*//;
5264 # Remove the entry entirely if there's no action left.
5265 if ($dbline{$i} eq '') {
5266 _remove_breakpoint_entry($filename, $i);
5272 sub delete_breakpoint {
5275 # If we got a line, delete just that one.
5276 if ( defined($i) ) {
5277 _delete_breakpoint_from_line($i);
5279 # No line; delete them all.
5281 _delete_all_breakpoints();
5287 =head3 cmd_stop (command)
5289 This is meant to be part of the new command API, but it isn't called or used
5290 anywhere else in the debugger. XXX It is probably meant for use in development
5295 sub cmd_stop { # As on ^C, but not signal-safy.
5299 =head3 C<cmd_e> - threads
5301 Display the current thread id:
5305 This could be how (when implemented) to send commands to this thread id (e cmd)
5306 or that thread id (e tid cmd).
5313 unless (exists($INC{'threads.pm'})) {
5314 print "threads not loaded($ENV{PERL5DB_THREADED})
5315 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5317 my $tid = threads->tid;
5318 print "thread id: $tid\n";
5322 =head3 C<cmd_E> - list of thread ids
5324 Display the list of available thread ids:
5328 This could be used (when implemented) to send commands to all threads (E cmd).
5335 unless (exists($INC{'threads.pm'})) {
5336 print "threads not loaded($ENV{PERL5DB_THREADED})
5337 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5339 my $tid = threads->tid;
5340 print "thread ids: ".join(', ',
5341 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
5346 =head3 C<cmd_h> - help command (command)
5348 Does the work of either
5354 Showing all the debugger help
5358 Showing help for a specific command
5365 use vars qw($summary);
5370 # If we have no operand, assume null.
5371 my $line = shift || '';
5373 # 'h h'. Print the long-format help.
5374 if ( $line =~ /\Ah\s*\z/ ) {
5378 # 'h <something>'. Search for the command and print only its help.
5379 elsif ( my ($asked) = $line =~ /\A(\S.*)\z/ ) {
5381 # support long commands; otherwise bogus errors
5382 # happen when you ask for h on <CR> for example
5383 my $qasked = quotemeta($asked); # for searching; we don't
5384 # want to use it as a pattern.
5385 # XXX: finds CR but not <CR>
5387 # Search the help string for the command.
5389 $help =~ /^ # Start of a line
5391 (?:[IB]<) # Optional markup
5392 $qasked # The requested command
5397 # It's there; pull it out and print it.
5401 (?:[IB]<) # Optional markup
5402 $qasked # The command
5403 ([\s\S]*?) # Description line(s)
5404 \n) # End of last description line
5405 (?!\s) # Next line not starting with
5414 # Not found; not a debugger command.
5416 print_help("B<$asked> is not a debugger command.\n");
5418 } ## end elsif ($line =~ /^(\S.*)$/)
5420 # 'h' - print the summary help.
5422 print_help($summary);
5426 =head3 C<cmd_i> - inheritance display
5428 Display the (nested) parentage of the module or object given.
5435 foreach my $isa ( split( /\s+/, $line ) ) {
5437 # The &-call is here to ascertain the mutability of @_.
5445 defined( ${"$_\::VERSION"} )
5446 ? ' ' . ${"$_\::VERSION"}
5448 } @{mro::get_linear_isa(ref($isa) || $isa)}
5454 =head3 C<cmd_l> - list lines (command)
5456 Most of the command is taken up with transforming all the different line
5457 specification syntaxes into 'start-stop'. After that is done, the command
5458 runs a loop over C<@dbline> for the specified range of lines. It handles
5459 the printing of each line and any markers (C<==E<gt>> for current line,
5460 C<b> for break on this line, C<a> for action on this line, C<:> for this
5463 We save the last line listed in the C<$start> global for further listing
5470 foreach my $v (@_) {
5480 foreach my $v (@_) {
5488 sub _minify_to_max {
5491 $$ref = _min($$ref, $max);
5496 sub _cmd_l_handle_var_name {
5497 my $var_name = shift;
5499 $evalarg = $var_name;
5501 my ($s) = DB::eval();
5503 # Ooops. Bad scalar.
5505 print {$OUT} "Error: $@\n";
5509 # Good scalar. If it's a reference, find what it points to.
5511 print {$OUT} "Interpreted as: $1 $s\n";
5514 # Call self recursively to really do the command.
5515 return _cmd_l_main( $s );
5518 sub _cmd_l_handle_subname {
5523 $subname =~ s/\'/::/;
5525 # Put it in this package unless it starts with ::.
5526 $subname = $package . "::" . $subname unless $subname =~ /::/;
5528 # Put it in CORE::GLOBAL if t doesn't start with :: and
5529 # it doesn't live in this package and it lives in CORE::GLOBAL.
5530 $subname = "CORE::GLOBAL::$s"
5531 if not defined &$subname
5533 and defined &{"CORE::GLOBAL::$s"};
5535 # Put leading '::' names into 'main::'.
5536 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
5538 # Get name:start-stop from find_sub, and break this up at
5540 my @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
5542 # Pull off start-stop.
5543 my $subrange = pop @pieces;
5545 # If the name contained colons, the split broke it up.
5546 # Put it back together.
5547 $file = join( ':', @pieces );
5549 # If we're not in that file, switch over to it.
5550 if ( $file ne $filename ) {
5551 if (! $slave_editor) {
5552 print {$OUT} "Switching to file '$file'.\n";
5555 # Switch debugger's magic structures.
5556 *dbline = $main::{ '_<' . $file };
5559 } ## end if ($file ne $filename)
5561 # Subrange is 'start-stop'. If this is less than a window full,
5562 # swap it to 'start+', which will list a window from the start point.
5564 if ( eval($subrange) < -$window ) {
5565 $subrange =~ s/-.*/+/;
5568 # Call self recursively to list the range.
5569 return _cmd_l_main( $subrange );
5570 } ## end if ($subrange)
5574 print {$OUT} "Subroutine $subname not found.\n";
5580 # Compute new range to list.
5581 $incr = $window - 1;
5584 return _cmd_l_main( $start . '-' . ( $start + $incr ) );
5588 my ($new_start, $new_incr) = @_;
5590 # Don't reset start for 'l +nnn'.
5591 $start = $new_start if $new_start;
5593 # Increment for list. Use window size if not specified.
5594 # (Allows 'l +' to work.)
5595 $incr = $new_incr || ($window - 1);
5597 # Create a line range we'll understand, and recurse to do it.
5598 return _cmd_l_main( $start . '-' . ( $start + $incr ) );
5601 sub _cmd_l_calc_initial_end_and_i {
5602 my ($spec, $start_match, $end_match) = @_;
5604 # Determine end point; use end of file if not specified.
5605 my $end = ( !defined $start_match ) ? $max :
5606 ( $end_match ? $end_match : $start_match );
5608 # Go on to the end, and then stop.
5609 _minify_to_max(\$end);
5611 # Determine start line.
5612 my $i = $start_match;
5626 my ($spec, $current_line, $start_match, $end_match) = @_;
5629 _cmd_l_calc_initial_end_and_i($spec, $start_match, $end_match);
5631 # If we're running under a slave editor, force it to show the lines.
5632 if ($slave_editor) {
5633 print {$OUT} "\032\032$filename:$i:0\n";
5636 # We're doing it ourselves. We want to show the line and special
5638 # - the current line in execution
5639 # - whether a line is breakable or not
5640 # - whether a line has a break or not
5641 # - whether a line has an action or not
5644 for ( ; $i <= $end ; $i++ ) {
5646 # Check for breakpoints and actions.
5647 my ( $stop, $action );
5649 ( $stop, $action ) = split( /\0/, $dbline{$i} );
5652 # ==> if this is the current line in execution,
5653 # : if it's breakable.
5655 ( $i == $current_line and $filename eq $filename_ini )
5657 : ( $dbline[$i] + 0 ? ':' : ' ' );
5659 # Add break and action indicators.
5660 $arrow .= 'b' if $stop;
5661 $arrow .= 'a' if $action;
5664 print {$OUT} "$i$arrow\t", $dbline[$i];
5666 # Move on to the next line. Drop out on an interrupt.
5671 } ## end for (; $i <= $end ; $i++)
5673 # Line the prompt up; print a newline if the last line listed
5674 # didn't have a newline.
5675 if ($dbline[ $i - 1 ] !~ /\n\z/) {
5678 } ## end else [ if ($slave_editor)
5680 # Save the point we last listed to in case another relative 'l'
5681 # command is desired. Don't let it run off the end.
5683 _minify_to_max(\$start);
5691 # If this is '-something', delete any spaces after the dash.
5692 $spec =~ s/\A-\s*\z/-/;
5694 # If the line is '$something', assume this is a scalar containing a
5696 # Set up for DB::eval() - evaluate in *user* context.
5697 if ( my ($var_name) = $spec =~ /\A(\$.*)/s ) {
5698 return _cmd_l_handle_var_name($var_name);
5700 # l name. Try to find a sub by that name.
5701 elsif ( ($subname) = $spec =~ /\A([\':A-Za-z_][\':\w]*(?:\[.*\])?)/s ) {
5702 return _cmd_l_handle_subname();
5705 elsif ( $spec !~ /\S/ ) {
5706 return _cmd_l_empty();
5708 # l [start]+number_of_lines
5709 elsif ( my ($new_start, $new_incr) = $spec =~ /\A(\d*)\+(\d*)\z/ ) {
5710 return _cmd_l_plus($new_start, $new_incr);
5712 # l start-stop or l start,stop
5713 elsif (my ($s, $e) = $spec =~ /^(?:(-?[\d\$\.]+)(?:[-,]([\d\$\.]+))?)?/ ) {
5714 return _cmd_l_range($spec, $line, $s, $e);
5721 my (undef, $line) = @_;
5723 return _cmd_l_main($line);
5726 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5728 To list breakpoints, the command has to look determine where all of them are
5729 first. It starts a C<%had_breakpoints>, which tells us what all files have
5730 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5731 magic source and breakpoint data structures) to the file, and then look
5732 through C<%dbline> for lines with breakpoints and/or actions, listing them
5733 out. We look through C<%postponed> not-yet-compiled subroutines that have
5734 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5735 that have breakpoints.
5737 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5741 sub _cmd_L_calc_arg {
5742 # If no argument, list everything. Pre-5.8.0 version always lists
5744 my $arg = shift || 'abw';
5745 if ($CommandSet ne '580')
5753 sub _cmd_L_calc_wanted_flags {
5754 my $arg = _cmd_L_calc_arg(shift);
5756 return (map { index($arg, $_) >= 0 ? 1 : 0 } qw(a b w));
5760 sub _cmd_L_handle_breakpoints {
5761 my ($handle_db_line) = @_;
5764 # Look in all the files with breakpoints...
5765 for my $file ( keys %had_breakpoints ) {
5767 # Temporary switch to this file.
5768 local *dbline = $main::{ '_<' . $file };
5770 # Set up to look through the whole file.
5772 my $was; # Flag: did we print something
5775 # For each line in the file ...
5776 for my $i (1 .. $max) {
5778 # We've got something on this line.
5779 if ( defined $dbline{$i} ) {
5781 # Print the header if we haven't.
5783 print {$OUT} "$file:\n";
5787 print {$OUT} " $i:\t", $dbline[$i];
5789 $handle_db_line->($dbline{$i});
5791 # Quit if the user hit interrupt.
5793 last BREAKPOINTS_SCAN;
5795 } ## end if (defined $dbline{$i...
5796 } ## end for my $i (1 .. $max)
5797 } ## end for my $file (keys %had_breakpoints)
5802 sub _cmd_L_handle_postponed_breakpoints {
5803 my ($handle_db_line) = @_;
5805 print {$OUT} "Postponed breakpoints in files:\n";
5808 for my $file ( keys %postponed_file ) {
5809 my $db = $postponed_file{$file};
5810 print {$OUT} " $file:\n";
5811 for my $line ( sort { $a <=> $b } keys %$db ) {
5812 print {$OUT} " $line:\n";
5814 $handle_db_line->($db->{$line});
5817 last POSTPONED_SCANS;
5821 last POSTPONED_SCANS;
5832 my ($action_wanted, $break_wanted, $watch_wanted) =
5833 _cmd_L_calc_wanted_flags(shift);
5835 my $handle_db_line = sub {
5838 my ( $stop, $action ) = split( /\0/, $l );
5840 if ($stop and $break_wanted) {
5841 print {$OUT} " break if (", $stop, ")\n"
5844 if ($action && $action_wanted) {
5845 print {$OUT} " action: ", $action, "\n"
5851 # Breaks and actions are found together, so we look in the same place
5853 if ( $break_wanted or $action_wanted ) {
5854 _cmd_L_handle_breakpoints($handle_db_line);
5857 # Look for breaks in not-yet-compiled subs:
5858 if ( %postponed and $break_wanted ) {
5859 print {$OUT} "Postponed breakpoints in subroutines:\n";
5862 for $subname ( keys %postponed ) {
5863 print {$OUT} " $subname\t$postponed{$subname}\n";
5868 } ## end if (%postponed and $break_wanted)
5870 # Find files that have not-yet-loaded breaks:
5871 my @have = map { # Combined keys
5872 keys %{ $postponed_file{$_} }
5873 } keys %postponed_file;
5875 # If there are any, list them.
5876 if ( @have and ( $break_wanted or $action_wanted ) ) {
5877 _cmd_L_handle_postponed_breakpoints($handle_db_line);
5878 } ## end if (@have and ($break_wanted...
5880 if ( %break_on_load and $break_wanted ) {
5881 print {$OUT} "Breakpoints on load:\n";
5882 BREAK_ON_LOAD: for my $filename ( keys %break_on_load ) {
5883 print {$OUT} " $filename\n";
5884 last BREAK_ON_LOAD if $signal;
5886 } ## end if (%break_on_load and...
5888 if ($watch_wanted and ( $trace & 2 )) {
5889 print {$OUT} "Watch-expressions:\n" if @to_watch;
5890 TO_WATCH: for my $expr (@to_watch) {
5891 print {$OUT} " $expr\n";
5892 last TO_WATCH if $signal;
5899 =head3 C<cmd_M> - list modules (command)
5901 Just call C<list_modules>.
5911 =head3 C<cmd_o> - options (command)
5913 If this is just C<o> by itself, we list the current settings via
5914 C<dump_option>. If there's a nonblank value following it, we pass that on to
5915 C<parse_options> for processing.
5921 my $opt = shift || ''; # opt[=val]
5923 # Nonblank. Try to parse and process.
5924 if ( $opt =~ /^(\S.*)/ ) {
5928 # Blank. List the current option settings.
5936 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5938 Advises the user that the O command has been renamed.
5943 print $OUT "The old O command is now the o command.\n"; # hint
5944 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5945 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5948 =head3 C<cmd_v> - view window (command)
5950 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5951 move back a few lines to list the selected line in context. Uses C<cmd_l>
5952 to do the actual listing after figuring out the range of line to request.
5956 use vars qw($preview);
5962 # Extract the line to list around. (Astute readers will have noted that
5963 # this pattern will match whether or not a numeric line is specified,
5964 # which means that we'll always enter this loop (though a non-numeric
5965 # argument results in no action at all)).
5966 if ( $line =~ /^(\d*)$/ ) {
5968 # Total number of lines to list (a windowful).
5969 $incr = $window - 1;
5971 # Set the start to the argument given (if there was one).
5974 # Back up by the context amount.
5977 # Put together a linespec that cmd_l will like.
5978 $line = $start . '-' . ( $start + $incr );
5981 cmd_l( 'l', $line );
5982 } ## end if ($line =~ /^(\d*)$/)
5985 =head3 C<cmd_w> - add a watch expression (command)
5987 The 5.8 version of this command adds a watch expression if one is specified;
5988 it does nothing if entered with no operands.
5990 We extract the expression, save it, evaluate it in the user's context, and
5991 save the value. We'll re-evaluate it each time the debugger passes a line,
5992 and will stop (see the code at the top of the command loop) if the value
5993 of any of the expressions changes.
5997 sub _add_watch_expr {
6001 push @to_watch, $expr;
6003 # Parameterize DB::eval and call it to get the expression's value
6004 # in the user's context. This version can handle expressions which
6005 # return a list value.
6007 # The &-call is here to ascertain the mutability of @_.
6008 my ($val) = join( ' ', &DB::eval);
6009 $val = ( defined $val ) ? "'$val'" : 'undef';
6011 # Save the current value of the expression.
6012 push @old_watch, $val;
6014 # We are now watching expressions.
6023 # Null expression if no arguments.
6024 my $expr = shift || '';
6026 # If expression is not null ...
6027 if ( $expr =~ /\A\S/ ) {
6028 _add_watch_expr($expr);
6029 } ## end if ($expr =~ /^(\S.*)/)
6031 # You have to give one to get one.
6033 print $OUT "Adding a watch-expression requires an expression\n"; # hint
6039 =head3 C<cmd_W> - delete watch expressions (command)
6041 This command accepts either a watch expression to be removed from the list
6042 of watch expressions, or C<*> to delete them all.
6044 If C<*> is specified, we simply empty the watch expression list and the
6045 watch expression value list. We also turn off the bit that says we've got
6048 If an expression (or partial expression) is specified, we pattern-match
6049 through the expressions and remove the ones that match. We also discard
6050 the corresponding values. If no watch expressions are left, we turn off
6051 the I<watching expressions> bit.
6057 my $expr = shift || '';
6060 if ( $expr eq '*' ) {
6065 print $OUT "Deleting all watch expressions ...\n";
6068 @to_watch = @old_watch = ();
6071 # Delete one of them.
6072 elsif ( $expr =~ /^(\S.*)/ ) {
6074 # Where we are in the list.
6077 # For each expression ...
6078 foreach (@to_watch) {
6079 my $val = $to_watch[$i_cnt];
6081 # Does this one match the command argument?
6082 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
6083 # Yes. Turn it off, and its value too.
6084 splice( @to_watch, $i_cnt, 1 );
6085 splice( @old_watch, $i_cnt, 1 );
6088 } ## end foreach (@to_watch)
6090 # We don't bother to turn watching off because
6091 # a) we don't want to stop calling watchfunction() if it exists
6092 # b) foreach over a null list doesn't do anything anyway
6094 } ## end elsif ($expr =~ /^(\S.*)/)
6096 # No command arguments entered.
6099 "Deleting a watch-expression requires an expression, or '*' for all\n"
6104 ### END of the API section
6106 =head1 SUPPORT ROUTINES
6108 These are general support routines that are used in a number of places
6109 throughout the debugger.
6113 save() saves the user's versions of globals that would mess us up in C<@saved>,
6114 and installs the versions we like better.
6120 # Save eval failure, command failure, extended OS error, output field
6121 # separator, input record separator, output record separator and
6122 # the warning setting.
6123 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
6125 $, = ""; # output field separator is null string
6126 $/ = "\n"; # input record separator is newline
6127 $\ = ""; # output record separator is null string
6128 $^W = 0; # warnings are off
6131 =head2 C<print_lineinfo> - show where we are now
6133 print_lineinfo prints whatever it is that it is handed; it prints it to the
6134 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
6135 us to feed line information to a slave editor without messing up the
6140 sub print_lineinfo {
6142 # Make the terminal sensible if we're not the primary debugger.
6143 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
6146 # $LINEINFO may be undef if $noTTY is set or some other issue.
6149 print {$LINEINFO} @_;
6151 } ## end sub print_lineinfo
6153 =head2 C<postponed_sub>
6155 Handles setting postponed breakpoints in subroutines once they're compiled.
6156 For breakpoints, we use C<DB::find_sub> to locate the source file and line
6157 range for the subroutine, then mark the file as having a breakpoint,
6158 temporarily switch the C<*dbline> glob over to the source file, and then
6159 search the given range of lines to find a breakable line. If we find one,
6160 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
6164 # The following takes its argument via $evalarg to preserve current @_
6168 # Get the subroutine name.
6169 my $subname = shift;
6171 # If this is a 'break +<n> if <condition>' ...
6172 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
6174 # If there's no offset, use '+0'.
6175 my $offset = $1 || 0;
6177 # find_sub's value is 'fullpath-filename:start-stop'. It's
6178 # possible that the filename might have colons in it too.
6179 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
6182 # We got the start line. Add the offset '+<n>' from
6183 # $postponed{subname}.
6186 # Switch to the file this sub is in, temporarily.
6187 local *dbline = $main::{ '_<' . $file };
6189 # No warnings, please.
6190 local $^W = 0; # != 0 is magical below
6192 # This file's got a breakpoint in it.
6193 $had_breakpoints{$file} |= 1;
6195 # Last line in file.
6198 # Search forward until we hit a breakable line or get to
6199 # the end of the file.
6200 ++$i until $dbline[$i] != 0 or $i >= $max;
6202 # Copy the breakpoint in and delete it from %postponed.
6203 $dbline{$i} = delete $postponed{$subname};
6206 # find_sub didn't find the sub.
6209 print $OUT "Subroutine $subname not found.\n";
6212 } ## end if ($postponed{$subname...
6213 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
6215 #print $OUT "In postponed_sub for '$subname'.\n";
6216 } ## end sub postponed_sub
6220 Called after each required file is compiled, but before it is executed;
6221 also called if the name of a just-compiled subroutine is a key of
6222 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
6223 etc.) into the just-compiled code.
6225 If this is a C<require>'d file, the incoming parameter is the glob
6226 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
6228 If it's a subroutine, the incoming parameter is the subroutine name.
6234 # If there's a break, process it.
6235 if ($ImmediateStop) {
6237 # Right, we've stopped. Turn it off.
6240 # Enter the command loop when DB::DB gets called.
6244 # If this is a subroutine, let postponed_sub() deal with it.
6245 if (ref(\$_[0]) ne 'GLOB') {
6246 return postponed_sub(@_);
6249 # Not a subroutine. Deal with the file.
6250 local *dbline = shift;
6251 my $filename = $dbline;
6252 $filename =~ s/^_<//;
6254 $signal = 1, print $OUT "'$filename' loaded...\n"
6255 if $break_on_load{$filename};
6256 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
6258 # Do we have any breakpoints to put in this file?
6259 return unless $postponed_file{$filename};
6261 # Yes. Mark this file as having breakpoints.
6262 $had_breakpoints{$filename} |= 1;
6264 # "Cannot be done: insufficient magic" - we can't just put the
6265 # breakpoints saved in %postponed_file into %dbline by assigning
6266 # the whole hash; we have to do it one item at a time for the
6267 # breakpoints to be set properly.
6268 #%dbline = %{$postponed_file{$filename}};
6270 # Set the breakpoints, one at a time.
6273 for $key ( keys %{ $postponed_file{$filename} } ) {
6275 # Stash the saved breakpoint into the current file's magic line array.
6276 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
6279 # This file's been compiled; discard the stored breakpoints.
6280 delete $postponed_file{$filename};
6282 } ## end sub postponed
6286 C<dumpit> is the debugger's wrapper around dumpvar.pl.
6288 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
6289 a reference to a variable (the thing to be dumped) as its input.
6291 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
6292 the currently-selected filehandle, thank you very much). The current
6293 values of the package globals C<$single> and C<$trace> are backed up in
6294 lexicals, and they are turned off (this keeps the debugger from trying
6295 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
6296 preserve its current value and it is set to zero to prevent entry/exit
6297 messages from printing, and C<$doret> is localized as well and set to -2 to
6298 prevent return values from being shown.
6300 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
6301 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
6302 installed version in C<@INC>, yours will be used instead. Possible security
6305 It then checks to see if the subroutine C<main::dumpValue> is now defined
6306 it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
6307 localizes the globals necessary for things to be sane when C<main::dumpValue()>
6308 is called, and picks up the variable to be dumped from the parameter list.
6310 It checks the package global C<%options> to see if there's a C<dumpDepth>
6311 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
6312 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
6313 structure: -1 means dump everything.
6315 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
6318 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
6319 and we then return to the caller.
6325 # Save the current output filehandle and switch to the one
6326 # passed in as the first parameter.
6327 my $savout = select(shift);
6329 # Save current settings of $single and $trace, and then turn them off.
6330 my $osingle = $single;
6331 my $otrace = $trace;
6332 $single = $trace = 0;
6334 # XXX Okay, what do $frame and $doret do, again?
6338 # Load dumpvar.pl unless we've already got the sub we need from it.
6339 unless ( defined &main::dumpValue ) {
6340 do 'dumpvar.pl' or die $@;
6343 # If the load succeeded (or we already had dumpvalue()), go ahead
6345 if ( defined &main::dumpValue ) {
6350 my $maxdepth = shift || $option{dumpDepth};
6351 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
6352 main::dumpValue( $v, $maxdepth );
6353 } ## end if (defined &main::dumpValue)
6355 # Oops, couldn't load dumpvar.pl.
6358 print $OUT "dumpvar.pl not available.\n";
6361 # Reset $single and $trace to their old values.
6365 # Restore the old filehandle.
6369 =head2 C<print_trace>
6371 C<print_trace>'s job is to print a stack trace. It does this via the
6372 C<dump_trace> routine, which actually does all the ferreting-out of the
6373 stack trace data. C<print_trace> takes care of formatting it nicely and
6374 printing it to the proper filehandle.
6382 The filehandle to print to.
6386 How many frames to skip before starting trace.
6390 How many frames to print.
6394 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
6398 The original comment below seems to be noting that the traceback may not be
6399 correct if this routine is called in a tied method.
6403 # Tied method do not create a context, so may get wrong message:
6409 # If this is going to a slave editor, but we're not the primary
6410 # debugger, reset it first.
6412 if $fh eq $LINEINFO # slave editor
6413 and $LINEINFO eq $OUT # normal output
6414 and $term_pid != $$; # not the primary
6416 # Collect the actual trace information to be formatted.
6417 # This is an array of hashes of subroutine call info.
6418 my @sub = dump_trace( $_[0] + 1, $_[1] );
6420 # Grab the "short report" flag from @_.
6421 my $short = $_[2]; # Print short report, next one for sub name
6423 # Run through the traceback info, format it, and print it.
6425 for my $i (0 .. $#sub) {
6427 # Drop out if the user has lost interest and hit control-C.
6430 # Set the separator so arrays print nice.
6433 # Grab and stringify the arguments if they are there.
6435 defined $sub[$i]{args}
6436 ? "(@{ $sub[$i]{args} })"
6439 # Shorten them up if $maxtrace says they're too long.
6440 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
6441 if length $args > $maxtrace;
6443 # Get the file name.
6444 my $file = $sub[$i]{file};
6446 # Put in a filename header if short is off.
6447 $file = $file eq '-e' ? $file : "file '$file'" unless $short;
6449 # Get the actual sub's name, and shorten to $maxtrace's requirement.
6450 $s = $sub[$i]{'sub'};
6451 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
6453 # Short report uses trimmed file and sub names.
6455 my $sub = @_ >= 4 ? $_[3] : $s;
6456 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
6457 } ## end if ($short)
6459 # Non-short report includes full names.
6461 print $fh "$sub[$i]{context} = $s$args"
6462 . " called from $file"
6463 . " line $sub[$i]{line}\n";
6465 } ## end for my $i (0 .. $#sub)
6466 } ## end sub print_trace
6468 =head2 dump_trace(skip[,count])
6470 Actually collect the traceback information available via C<caller()>. It does
6471 some filtering and cleanup of the data, but mostly it just collects it to
6472 make C<print_trace()>'s job easier.
6474 C<skip> defines the number of stack frames to be skipped, working backwards
6475 from the most current. C<count> determines the total number of frames to
6476 be returned; all of them (well, the first 10^9) are returned if C<count>
6479 This routine returns a list of hashes, from most-recent to least-recent
6480 stack frame. Each has the following keys and values:
6484 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
6486 =item * C<sub> - subroutine name, or C<eval> information
6488 =item * C<args> - undef, or a reference to an array of arguments
6490 =item * C<file> - the file in which this item was defined (if any)
6492 =item * C<line> - the line on which it was defined
6498 sub _dump_trace_calc_saved_single_arg
6500 my ($nothard, $arg) = @_;
6503 if ( not defined $arg ) { # undefined parameter
6507 elsif ( $nothard and tied $arg ) { # tied parameter
6510 elsif ( $nothard and $type = ref $arg ) { # reference
6511 return "ref($type)";
6513 else { # can be stringified
6515 "$arg"; # Safe to stringify now - should not call f().
6517 # Backslash any single-quotes or backslashes.
6520 # Single-quote it unless it's a number or a colon-separated
6523 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
6525 # Turn high-bit characters into meta-whatever.
6526 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
6528 # Turn control characters into ^-whatever.
6529 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
6535 sub _dump_trace_calc_save_args {
6539 map { _dump_trace_calc_saved_single_arg($nothard, $_) } @args
6545 # How many levels to skip.
6548 # How many levels to show. (1e9 is a cheap way of saying "all of them";
6549 # it's unlikely that we'll have more than a billion stack frames. If you
6550 # do, you've got an awfully big machine...)
6551 my $count = shift || 1e9;
6553 # We increment skip because caller(1) is the first level *back* from
6554 # the current one. Add $skip to the count of frames so we have a
6555 # simple stop criterion, counting from $skip to $count+$skip.
6559 # These variables are used to capture output from caller();
6560 my ( $p, $file, $line, $sub, $h, $context );
6562 my ( $e, $r, @sub, $args );
6564 # XXX Okay... why'd we do that?
6565 my $nothard = not $frame & 8;
6568 # Do not want to trace this.
6569 my $otrace = $trace;
6572 # Start out at the skip count.
6573 # If we haven't reached the number of frames requested, and caller() is
6574 # still returning something, stay in the loop. (If we pass the requested
6575 # number of stack frames, or we run out - caller() returns nothing - we
6577 # Up the stack frame index to go back one more level each time.
6581 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
6586 # Go through the arguments and save them for later.
6587 my $save_args = _dump_trace_calc_save_args($nothard);
6589 # If context is true, this is array (@)context.
6590 # If context is false, this is scalar ($) context.
6591 # If neither, context isn't defined. (This is apparently a 'can't
6593 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
6595 # if the sub has args ($h true), make an anonymous array of the
6597 $args = $h ? $save_args : undef;
6599 # remove trailing newline-whitespace-semicolon-end of line sequence
6600 # from the eval text, if any.
6601 $e =~ s/\n\s*\;\s*\Z// if $e;
6603 # Escape backslashed single-quotes again if necessary.
6604 $e =~ s/([\\\'])/\\$1/g if $e;
6606 # if the require flag is true, the eval text is from a require.
6608 $sub = "require '$e'";
6611 # if it's false, the eval text is really from an eval.
6612 elsif ( defined $r ) {
6616 # If the sub is '(eval)', this is a block eval, meaning we don't
6617 # know what the eval'ed text actually was.
6618 elsif ( $sub eq '(eval)' ) {
6619 $sub = "eval {...}";
6622 # Stick the collected information into @sub as an anonymous hash.
6626 context => $context,
6634 # Stop processing frames if the user hit control-C.
6636 } ## end for ($i = $skip ; $i < ...
6638 # Restore the trace value again.
6641 } ## end sub dump_trace
6645 C<action()> takes input provided as the argument to an add-action command,
6646 either pre- or post-, and makes sure it's a complete command. It doesn't do
6647 any fancy parsing; it just keeps reading input until it gets a string
6648 without a trailing backslash.
6655 while ( $action =~ s/\\$// ) {
6657 # We have a backslash on the end. Read more.
6659 } ## end while ($action =~ s/\\$//)
6661 # Return the assembled action.
6667 This routine mostly just packages up a regular expression to be used
6668 to check that the thing it's being matched against has properly-matched
6671 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
6672 speeds things up by only creating the qr//'ed expression once; if it's
6673 already defined, we don't try to define it again. A speed hack.
6677 use vars qw($balanced_brace_re);
6681 # I hate using globals!
6682 $balanced_brace_re ||= qr{
6685 (?> [^{}] + ) # Non-parens without backtracking
6687 (??{ $balanced_brace_re }) # Group with matching parens
6691 return $_[0] !~ m/$balanced_brace_re/;
6692 } ## end sub unbalanced
6696 C<gets()> is a primitive (very primitive) routine to read continuations.
6697 It was devised for reading continuations for actions.
6698 it just reads more input with C<readline()> and returns it.
6703 return DB::readline("cont: ");
6706 =head2 C<_db_system()> - handle calls to<system()> without messing up the debugger
6708 The C<system()> function assumes that it can just go ahead and use STDIN and
6709 STDOUT, but under the debugger, we want it to use the debugger's input and
6712 C<_db_system()> socks away the program's STDIN and STDOUT, and then substitutes
6713 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
6714 and then puts everything back again.
6720 # We save, change, then restore STDIN and STDOUT to avoid fork() since
6721 # some non-Unix systems can do system() but have problems with fork().
6722 open( SAVEIN, "<&STDIN" ) || db_warn("Can't save STDIN");
6723 open( SAVEOUT, ">&STDOUT" ) || db_warn("Can't save STDOUT");
6724 open( STDIN, "<&IN" ) || db_warn("Can't redirect STDIN");
6725 open( STDOUT, ">&OUT" ) || db_warn("Can't redirect STDOUT");
6727 # XXX: using csh or tcsh destroys sigint retvals!
6729 open( STDIN, "<&SAVEIN" ) || db_warn("Can't restore STDIN");
6730 open( STDOUT, ">&SAVEOUT" ) || db_warn("Can't restore STDOUT");
6734 # most of the $? crud was coping with broken cshisms
6736 db_warn( "(Command exited ", ( $? >> 8 ), ")\n" );
6740 "(Command died of SIG#",
6742 ( ( $? & 128 ) ? " -- core dumped" : "" ),
6751 *system = \&_db_system;
6753 =head1 TTY MANAGEMENT
6755 The subs here do some of the terminal management for multiple debuggers.
6759 Top-level function called when we want to set up a new terminal for use
6762 If the C<noTTY> debugger option was set, we'll either use the terminal
6763 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
6764 to find one. If we're a forked debugger, we call C<resetterm> to try to
6765 get a whole new terminal if we can.
6767 In either case, we set up the terminal next. If the C<ReadLine> option was
6768 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6769 the appropriate attributes. We then
6773 use vars qw($ornaments);
6774 use vars qw($rl_attribs);
6778 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6781 require Term::ReadLine;
6783 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6786 my ( $i, $o ) = split $tty, /,/;
6787 $o = $i unless defined $o;
6788 open( IN, "<$i" ) or die "Cannot open TTY '$i' for read: $!";
6789 open( OUT, ">$o" ) or die "Cannot open TTY '$o' for write: $!";
6795 # We don't have a TTY - try to find one via Term::Rendezvous.
6797 require Term::Rendezvous;
6799 # See if we have anything to pass to Term::Rendezvous.
6800 # Use $HOME/.perldbtty$$ if not.
6801 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6803 # Rendezvous and get the filehandles.
6804 my $term_rv = Term::Rendezvous->new( $rv );
6806 $OUT = $term_rv->OUT;
6807 } ## end else [ if ($tty)
6808 } ## end if ($notty)
6810 # We're a daughter debugger. Try to fork off another TTY.
6811 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6815 # If we shouldn't use Term::ReadLine, don't.
6817 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6820 # We're using Term::ReadLine. Get all the attributes for this terminal.
6822 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6824 $rl_attribs = $term->Attribs;
6825 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6826 if defined $rl_attribs->{basic_word_break_characters}
6827 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6828 $rl_attribs->{special_prefixes} = '$@&%';
6829 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6830 $rl_attribs->{completion_function} = \&db_complete;
6831 } ## end else [ if (!$rl)
6833 # Set up the LINEINFO filehandle.
6834 $LINEINFO = $OUT unless defined $LINEINFO;
6835 $lineinfo = $console unless defined $lineinfo;
6841 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6842 $term->SetHistory(@hist);
6845 # XXX Ornaments are turned on unconditionally, which is not
6846 # always a good thing.
6847 ornaments($ornaments) if defined $ornaments;
6849 } ## end sub setterm
6852 $histfile //= option_val("HistFile", undef);
6853 return unless defined $histfile;
6854 open my $fh, "<", $histfile or return;
6865 return unless defined $histfile;
6866 eval { require File::Path } or return;
6867 eval { require File::Basename } or return;
6868 File::Path::mkpath(File::Basename::dirname($histfile));
6869 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6870 $histsize //= option_val("HistSize",100);
6871 my @copy = grep { $_ ne '?' } @hist;
6872 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6873 for ($start .. $#copy) {
6874 print $fh "$copy[$_]\n";
6876 close $fh or die "Could not write '$histfile': $!";
6879 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6881 When the process being debugged forks, or the process invokes a command
6882 via C<system()> which starts a new debugger, we need to be able to get a new
6883 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6884 fight over the terminal, and you can never quite be sure who's going to get the
6885 input you're typing.
6887 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6888 is tasked with doing all the necessary operating system mojo to get a new
6889 TTY (and probably another window) and to direct the new debugger to read and
6892 The debugger provides C<get_fork_TTY> functions which work for TCP
6893 socket servers, X11, OS/2, and Mac OS X. Other systems are not
6894 supported. You are encouraged to write C<get_fork_TTY> functions which
6895 work for I<your> platform and contribute them.
6897 =head3 C<socket_get_fork_TTY>
6901 sub connect_remoteport {
6904 my $socket = IO::Socket::INET->new(
6906 PeerAddr => $remoteport,
6910 die "Unable to connect to remote host: $remoteport\n";
6915 sub socket_get_fork_TTY {
6916 $tty = $LINEINFO = $IN = $OUT = connect_remoteport();
6918 # Do I need to worry about setting $term?
6920 reset_IN_OUT( $IN, $OUT );
6924 =head3 C<xterm_get_fork_TTY>
6926 This function provides the C<get_fork_TTY> function for X11. If a
6927 program running under the debugger forks, a new <xterm> window is opened and
6928 the subsidiary debugger is directed there.
6930 The C<open()> call is of particular note here. We have the new C<xterm>
6931 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6932 command (which prints the device name of the TTY we'll want to use for input
6933 and output to STDOUT, then C<sleep> for a very long time, routing this output
6934 to file number 3. This way we can simply read from the <XT> filehandle (which
6935 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6937 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6942 sub xterm_get_fork_TTY {
6943 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6945 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6948 # Get the output from 'tty' and clean it up a little.
6952 $pidprompt = ''; # Shown anyway in titlebar
6954 # We need $term defined or we can not switch to the newly created xterm
6955 if ($tty ne '' && !defined $term) {
6956 require Term::ReadLine;
6958 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6961 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6964 # There's our new TTY.
6966 } ## end sub xterm_get_fork_TTY
6968 =head3 C<os2_get_fork_TTY>
6970 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6974 # This example function resets $IN, $OUT itself
6976 sub os2_get_fork_TTY { # A simplification of the following (and works without):
6978 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6979 my %opt = ( title => "Daughter Perl debugger $pids $name",
6980 ($rl ? (read_by_key => 1) : ()) );
6981 require OS2::Process;
6982 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
6984 $pidprompt = ''; # Shown anyway in titlebar
6985 reset_IN_OUT($in, $out);
6987 return ''; # Indicate that reset_IN_OUT is called
6988 } ## end sub os2_get_fork_TTY
6990 =head3 C<macosx_get_fork_TTY>
6992 The Mac OS X version uses AppleScript to tell Terminal.app to create
6997 # Notes about Terminal.app's AppleScript support,
6998 # (aka things that might break in future OS versions).
7000 # The "do script" command doesn't return a reference to the new window
7001 # it creates, but since it appears frontmost and windows are enumerated
7002 # front to back, we can use "first window" === "window 1".
7004 # Since "do script" is implemented by supplying the argument (plus a
7005 # return character) as terminal input, there's a potential race condition
7006 # where the debugger could beat the shell to reading the command.
7007 # To prevent this, we wait for the screen to clear before proceeding.
7010 # There's no direct accessor for the tty device name, so we fiddle
7011 # with the window title options until it says what we want.
7014 # There _is_ a direct accessor for the tty device name, _and_ there's
7015 # a new possible component of the window title (the name of the settings
7016 # set). A separate version is needed.
7018 my @script_versions=
7020 ([237, <<'__LEOPARD__'],
7021 tell application "Terminal"
7022 do script "clear;exec sleep 100000"
7023 tell first tab of first window
7025 set custom title to "forked perl debugger"
7026 set title displays custom title to true
7027 repeat while (length of first paragraph of (get contents)) > 0
7035 [100, <<'__JAGUAR_TIGER__'],
7036 tell application "Terminal"
7037 do script "clear;exec sleep 100000"
7039 set title displays shell path to false
7040 set title displays window size to false
7041 set title displays file name to false
7042 set title displays device name to true
7043 set title displays custom title to true
7044 set custom title to ""
7045 copy "/dev/" & name to thetty
7046 set custom title to "forked perl debugger"
7047 repeat while (length of first paragraph of (get contents)) > 0
7057 sub macosx_get_fork_TTY
7059 my($version,$script,$pipe,$tty);
7061 return unless $version=$ENV{TERM_PROGRAM_VERSION};
7062 foreach my $entry (@script_versions) {
7063 if ($version>=$entry->[0]) {
7064 $script=$entry->[1];
7068 return unless defined($script);
7069 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script);
7070 $tty=readline($pipe);
7072 return unless defined($tty) && $tty =~ m(^/dev/);
7077 =head2 C<create_IN_OUT($flags)>
7079 Create a new pair of filehandles, pointing to a new TTY. If impossible,
7080 try to diagnose why.
7086 =item * 1 - Don't know how to create a new TTY.
7088 =item * 2 - Debugger has forked, but we can't get a new TTY.
7090 =item * 4 - standard debugger startup is happening.
7096 use vars qw($fork_TTY);
7098 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
7100 # If we know how to get a new TTY, do it! $in will have
7101 # the TTY name if get_fork_TTY works.
7102 my $in = get_fork_TTY(@_) if defined &get_fork_TTY;
7104 # It used to be that
7105 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
7107 if ( not defined $in ) {
7110 # We don't know how.
7111 print_help(<<EOP) if $why == 1;
7112 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
7116 print_help(<<EOP) if $why == 2;
7117 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
7118 This may be an asynchronous session, so the parent debugger may be active.
7121 # Note that both debuggers are fighting over the same input.
7122 print_help(<<EOP) if $why != 4;
7123 Since two debuggers fight for the same TTY, input is severely entangled.
7127 I know how to switch the output to a different window in xterms, OS/2
7128 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
7129 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
7130 B<DB::get_fork_TTY()> returning this.
7132 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
7133 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
7136 } ## end if (not defined $in)
7137 elsif ( $in ne '' ) {
7141 $console = ''; # Indicate no need to open-from-the-console
7144 } ## end sub create_IN_OUT
7148 Handles rejiggering the prompt when we've forked off a new debugger.
7150 If the new debugger happened because of a C<system()> that invoked a
7151 program under the debugger, the arrow between the old pid and the new
7152 in the prompt has I<two> dashes instead of one.
7154 We take the current list of pids and add this one to the end. If there
7155 isn't any list yet, we make one up out of the initial pid associated with
7156 the terminal and our new pid, sticking an arrow (either one-dashed or
7157 two dashed) in between them.
7159 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
7160 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
7165 sub resetterm { # We forked, so we need a different TTY
7167 # Needs to be passed to create_IN_OUT() as well.
7170 # resetterm(2): got in here because of a system() starting a debugger.
7171 # resetterm(1): just forked.
7172 my $systemed = $in > 1 ? '-' : '';
7174 # If there's already a list of pids, add this to the end.
7176 $pids =~ s/\]/$systemed->$$]/;
7179 # No pid list. Time to make one.
7181 $pids = "[$term_pid->$$]";
7184 # The prompt we're going to be using for this debugger.
7187 # We now 0wnz this terminal.
7190 # Just return if we're not supposed to try to create a new TTY.
7191 return unless $CreateTTY & $in;
7193 # Try to create a new IN/OUT pair.
7195 } ## end sub resetterm
7199 First, we handle stuff in the typeahead buffer. If there is any, we shift off
7200 the next line, print a message saying we got it, add it to the terminal
7201 history (if possible), and return it.
7203 If there's nothing in the typeahead buffer, check the command filehandle stack.
7204 If there are any filehandles there, read from the last one, and return the line
7205 if we got one. If not, we pop the filehandle off and close it, and try the
7206 next one up the stack.
7208 If we've emptied the filehandle stack, we check to see if we've got a socket
7209 open, and we read that and return it if we do. If we don't, we just call the
7210 core C<readline()> and return its value.
7216 # Localize to prevent it from being smashed in the program being debugged.
7219 # If there are stacked filehandles to read from ...
7220 # (Handle it before the typeahead, because we may call source/etc. from
7224 # Read from the last one in the stack.
7225 my $line = CORE::readline( $cmdfhs[-1] );
7227 # If we got a line ...
7229 ? ( print $OUT ">> $line" and return $line ) # Echo and return
7230 : close pop @cmdfhs; # Pop and close
7231 } ## end while (@cmdfhs)
7233 # Pull a line out of the typeahead if there's stuff there.
7236 # How many lines left.
7237 my $left = @typeahead;
7239 # Get the next line.
7240 my $got = shift @typeahead;
7242 # Print a message saying we got input from the typeahead.
7244 print $OUT "auto(-$left)", shift, $got, "\n";
7246 # Add it to the terminal history (if possible).
7247 $term->AddHistory($got)
7249 and defined $term->Features->{addHistory};
7251 } ## end if (@typeahead)
7253 # We really need to read some input. Turn off entry/exit trace and
7254 # return value printing.
7258 # Nothing on the filehandle stack. Socket?
7259 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
7261 # Send anything we have to send.
7262 $OUT->write( join( '', @_ ) );
7264 # Receive anything there is to receive.
7269 while ($first_time or (length($buf) && ($stuff .= $buf) !~ /\n/))
7272 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
7273 # XXX Don't know. You tell me.
7278 } ## end if (ref $OUT and UNIVERSAL::isa...
7280 # No socket. Just read from the terminal.
7282 return $term->readline(@_);
7284 } ## end sub readline
7286 =head1 OPTIONS SUPPORT ROUTINES
7288 These routines handle listing and setting option values.
7290 =head2 C<dump_option> - list the current value of an option setting
7292 This routine uses C<option_val> to look up the value for an option.
7293 It cleans up escaped single-quotes and then displays the option and
7299 my ( $opt, $val ) = @_;
7300 $val = option_val( $opt, 'N/A' );
7301 $val =~ s/([\\\'])/\\$1/g;
7302 printf $OUT "%20s = '%s'\n", $opt, $val;
7303 } ## end sub dump_option
7305 sub options2remember {
7306 foreach my $k (@RememberOnROptions) {
7307 $option{$k} = option_val( $k, 'N/A' );
7312 =head2 C<option_val> - find the current value of an option
7314 This can't just be a simple hash lookup because of the indirect way that
7315 the option values are stored. Some are retrieved by calling a subroutine,
7316 some are just variables.
7318 You must supply a default value to be used in case the option isn't set.
7323 my ( $opt, $default ) = @_;
7326 # Does this option exist, and is it a variable?
7327 # If so, retrieve the value via the value in %optionVars.
7328 if ( defined $optionVars{$opt}
7329 and defined ${ $optionVars{$opt} } )
7331 $val = ${ $optionVars{$opt} };
7334 # Does this option exist, and it's a subroutine?
7335 # If so, call the subroutine via the ref in %optionAction
7336 # and capture the value.
7337 elsif ( defined $optionAction{$opt}
7338 and defined &{ $optionAction{$opt} } )
7340 $val = &{ $optionAction{$opt} }();
7343 # If there's an action or variable for the supplied option,
7344 # but no value was set, use the default.
7345 elsif (defined $optionAction{$opt} and not defined $option{$opt}
7346 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
7351 # Otherwise, do the simple hash lookup.
7353 $val = $option{$opt};
7356 # If the value isn't defined, use the default.
7357 # Then return whatever the value is.
7358 $val = $default unless defined $val;
7360 } ## end sub option_val
7362 =head2 C<parse_options>
7364 Handles the parsing and execution of option setting/displaying commands.
7366 An option entered by itself is assumed to be I<set me to 1> (the default value)
7367 if the option is a boolean one. If not, the user is prompted to enter a valid
7368 value or to query the current value (via C<option? >).
7370 If C<option=value> is entered, we try to extract a quoted string from the
7371 value (if it is quoted). If it's not, we just use the whole value as-is.
7373 We load any modules required to service this option, and then we set it: if
7374 it just gets stuck in a variable, we do that; if there's a subroutine to
7375 handle setting the option, we call that.
7377 Finally, if we're running in interactive mode, we display the effect of the
7378 user's command back to the terminal, skipping this if we're setting things
7379 during initialization.
7389 # These options need a value. Don't allow them to be clobbered by accident.
7390 my %opt_needs_val = map { ( $_ => 1 ) } qw{
7391 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
7392 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
7395 while (length($s)) {
7398 # Clean off excess leading whitespace.
7399 $s =~ s/^\s+// && next;
7401 # Options are always all word characters, followed by a non-word
7403 if ($s !~ s/^(\w+)(\W?)//) {
7404 print {$OUT} "Invalid option '$s'\n";
7407 my ( $opt, $sep ) = ( $1, $2 );
7409 # Make sure that such an option exists.
7410 my $matches = ( grep { /^\Q$opt/ && ( $option = $_ ) } @options )
7411 || ( grep { /^\Q$opt/i && ( $option = $_ ) } @options );
7414 print {$OUT} "Unknown option '$opt'\n";
7418 print {$OUT} "Ambiguous option '$opt'\n";
7423 # '?' as separator means query, but must have whitespace after it.
7424 if ( "?" eq $sep ) {
7426 print {$OUT} "Option query '$opt?' followed by non-space '$s'\n" ;
7431 #&dump_option($opt);
7432 } ## end if ("?" eq $sep)
7434 # Separator is whitespace (or just a carriage return).
7435 # They're going for a default, which we assume is 1.
7436 elsif ( $sep !~ /\S/ ) {
7438 $val = "1"; # this is an evil default; make 'em set it!
7441 # Separator is =. Trying to set a value.
7442 elsif ( $sep eq "=" ) {
7444 # If quoted, extract a quoted string.
7445 if ($s =~ s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
7447 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
7450 # Not quoted. Use the whole thing. Warn about 'option='.
7454 print OUT qq(Option better cleared using $opt=""\n)
7456 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
7458 } ## end elsif ($sep eq "=")
7460 # "Quoted" with [], <>, or {}.
7461 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
7463 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
7464 $s =~ s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
7465 or print( $OUT "Unclosed option value '$opt$sep$_'\n" ), last;
7466 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
7467 } ## end else [ if ("?" eq $sep)
7469 # Exclude non-booleans from getting set to 1 by default.
7470 if ( $opt_needs_val{$option} && $val_defaulted ) {
7471 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
7473 "Option '$opt' is non-boolean. Use '$cmd $option=VAL' to set, '$cmd $option?' to query\n";
7475 } ## end if ($opt_needs_val{$option...
7477 # Save the option value.
7478 $option{$option} = $val if defined $val;
7480 # Load any module that this option requires.
7481 if ( defined($optionRequire{$option}) && defined($val) ) {
7485 require '$optionRequire{$option}';
7487 } || die $@ # XXX: shouldn't happen
7491 # Stick it in the proper variable if it goes in a variable.
7492 if (defined($optionVars{$option}) && defined($val)) {
7493 ${ $optionVars{$option} } = $val;
7496 # Call the appropriate sub if it gets set via sub.
7497 if (defined($optionAction{$option})
7498 && defined (&{ $optionAction{$option} })
7501 &{ $optionAction{$option} }($val);
7504 # Not initialization - echo the value we set it to.
7505 dump_option($option) if ($OUT ne \*STDERR);
7506 } ## end while (length)
7507 } ## end sub parse_options
7509 =head1 RESTART SUPPORT
7511 These routines are used to store (and restore) lists of items in environment
7512 variables during a restart.
7516 Set_list packages up items to be stored in a set of environment variables
7517 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
7518 the values). Values outside the standard ASCII charset are stored by encoding
7519 then as hexadecimal values.
7524 my ( $stem, @list ) = @_;
7527 # VAR_n: how many we have. Scalar assignment gets the number of items.
7528 $ENV{"${stem}_n"} = @list;
7530 # Grab each item in the list, escape the backslashes, encode the non-ASCII
7531 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
7532 for my $i ( 0 .. $#list ) {
7534 $val =~ s/\\/\\\\/g;
7535 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
7536 $ENV{"${stem}_$i"} = $val;
7537 } ## end for $i (0 .. $#list)
7538 } ## end sub set_list
7542 Reverse the set_list operation: grab VAR_n to see how many we should be getting
7543 back, and then pull VAR_0, VAR_1. etc. back out.
7550 my $n = delete $ENV{"${stem}_n"};
7552 for my $i ( 0 .. $n - 1 ) {
7553 $val = delete $ENV{"${stem}_$i"};
7554 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
7558 } ## end sub get_list
7560 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
7564 The C<catch()> subroutine is the essence of fast and low-impact. We simply
7565 set an already-existing global scalar variable to a constant value. This
7566 avoids allocating any memory possibly in the middle of something that will
7567 get all confused if we do, particularly under I<unsafe signals>.
7573 return; # Put nothing on the stack - malloc/free land!
7578 C<warn> emits a warning, by joining together its arguments and printing
7579 them, with couple of fillips.
7581 If the composited message I<doesn't> end with a newline, we automatically
7582 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
7583 to be set to the filehandle to be used to output warnings; it makes no
7584 assumptions about what filehandles are available.
7589 my ($msg) = join( "", @_ );
7590 $msg .= ": $!\n" unless $msg =~ /\n$/;
7597 =head1 INITIALIZATION TTY SUPPORT
7599 =head2 C<reset_IN_OUT>
7601 This routine handles restoring the debugger's input and output filehandles
7602 after we've tried and failed to move them elsewhere. In addition, it assigns
7603 the debugger's output filehandle to $LINEINFO if it was already open there.
7608 my $switch_li = $LINEINFO eq $OUT;
7610 # If there's a term and it's able to get a new tty, try to get one.
7611 if ( $term and $term->Features->{newTTY} ) {
7612 ( $IN, $OUT ) = ( shift, shift );
7613 $term->newTTY( $IN, $OUT );
7616 # This term can't get a new tty now. Better luck later.
7618 _db_warn("Too late to set IN/OUT filehandles, enabled on next 'R'!\n");
7621 # Set the filehndles up as they were.
7623 ( $IN, $OUT ) = ( shift, shift );
7626 # Unbuffer the output filehandle.
7629 # Point LINEINFO to the same output filehandle if it was there before.
7630 $LINEINFO = $OUT if $switch_li;
7631 } ## end sub reset_IN_OUT
7633 =head1 OPTION SUPPORT ROUTINES
7635 The following routines are used to process some of the more complicated
7640 Sets the input and output filehandles to the specified files or pipes.
7641 If the terminal supports switching, we go ahead and do it. If not, and
7642 there's already a terminal in place, we save the information to take effect
7645 If there's no terminal yet (for instance, during debugger initialization),
7646 we go ahead and set C<$console> and C<$tty> to the file indicated.
7652 if ( @_ and $term and $term->Features->{newTTY} ) {
7654 # This terminal supports switching to a new TTY.
7655 # Can be a list of two files, or on string containing both names,
7657 # XXX Should this perhaps be an assignment from @_?
7658 my ( $in, $out ) = shift;
7661 # Split list apart if supplied.
7662 ( $in, $out ) = split /,/, $in, 2;
7666 # Use the same file for both input and output.
7670 # Open file onto the debugger's filehandles, if you can.
7671 open IN, $in or die "cannot open '$in' for read: $!";
7672 open OUT, ">$out" or die "cannot open '$out' for write: $!";
7674 # Swap to the new filehandles.
7675 reset_IN_OUT( \*IN, \*OUT );
7677 # Save the setting for later.
7679 } ## end if (@_ and $term and $term...
7681 # Terminal doesn't support new TTY, or doesn't support readline.
7682 # Can't do it now, try restarting.
7684 _db_warn("Too late to set TTY, enabled on next 'R'!\n");
7687 # Useful if done through PERLDB_OPTS:
7688 $console = $tty = shift if @_;
7690 # Return whatever the TTY is.
7696 Sets the C<$notty> global, controlling whether or not the debugger tries to
7697 get a terminal to read from. If called after a terminal is already in place,
7698 we save the value to use it if we're restarted.
7704 _db_warn("Too late to set noTTY, enabled on next 'R'!\n") if @_;
7706 $notty = shift if @_;
7712 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
7713 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
7714 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
7715 the value in case a restart is done so we can change it then.
7721 _db_warn("Too late to set ReadLine, enabled on next 'R'!\n") if @_;
7725 } ## end sub ReadLine
7727 =head2 C<RemotePort>
7729 Sets the port that the debugger will try to connect to when starting up.
7730 If the terminal's already been set up, we can't do it, but we remember the
7731 setting in case the user does a restart.
7737 _db_warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
7739 $remoteport = shift if @_;
7741 } ## end sub RemotePort
7745 Checks with the terminal to see if C<Tk> is running, and returns true or
7746 false. Returns false if the current terminal doesn't support C<readline>.
7751 if ( ${ $term->Features }{tkRunning} ) {
7752 return $term->tkRunning(@_);
7756 print $OUT "tkRunning not supported by current ReadLine package.\n";
7759 } ## end sub tkRunning
7763 Sets nonstop mode. If a terminal's already been set up, it's too late; the
7764 debugger remembers the setting in case you restart, though.
7770 _db_warn("Too late to set up NonStop mode, enabled on next 'R'!\n")
7773 $runnonstop = shift if @_;
7775 } ## end sub NonStop
7779 _db_warn("Some flag changes could not take effect until next 'R'!\n")
7782 $^P = parse_DollarCaretP_flags(shift) if @_;
7783 expand_DollarCaretP_flags($^P);
7788 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
7796 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
7803 Sets the shell escape command, and generates a printable copy to be used
7810 # If we got an argument, meta-quote it, and add '\b' if it
7811 # ends in a word character.
7813 $sh = quotemeta shift;
7814 $sh .= "\\b" if $sh =~ /\w$/;
7817 # Generate the printable version for the help:
7818 $psh = $sh; # copy it
7819 $psh =~ s/\\b$//; # Take off trailing \b if any
7820 $psh =~ s/\\(.)/$1/g; # De-escape
7821 $psh; # return the printable version
7822 } ## end sub shellBang
7826 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7827 was passed as the argument. (This means you can't override the terminal's
7833 if ( defined $term ) {
7835 # We don't want to show warning backtraces, but we do want die() ones.
7836 local $warnLevel = 0;
7837 local $dieLevel = 1;
7839 # No ornaments if the terminal doesn't support them.
7840 if (not $term->Features->{ornaments}) {
7844 return (eval { $term->ornaments(@_) } || '');
7847 # Use what was passed in if we can't determine it ourselves.
7854 } ## end sub ornaments
7856 =head2 C<recallCommand>
7858 Sets the recall command, and builds a printable version which will appear in
7865 # If there is input, metaquote it. Add '\b' if it ends with a word
7868 $rc = quotemeta shift;
7869 $rc .= "\\b" if $rc =~ /\w$/;
7872 # Build it into a printable version.
7873 $prc = $rc; # Copy it
7874 $prc =~ s/\\b$//; # Remove trailing \b
7875 $prc =~ s/\\(.)/$1/g; # Remove escapes
7876 return $prc; # Return the printable version
7877 } ## end sub recallCommand
7879 =head2 C<LineInfo> - where the line number information goes
7881 Called with no arguments, returns the file or pipe that line info should go to.
7883 Called with an argument (a file or a pipe), it opens that onto the
7884 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7885 file or pipe again to the caller.
7893 # If this is a valid "thing to be opened for output", tack a
7894 # '>' onto the front.
7895 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7897 # If this is a pipe, the stream points to a slave editor.
7898 $slave_editor = ( $stream =~ /^\|/ );
7900 my $new_lineinfo_fh;
7901 # Open it up and unbuffer it.
7902 open ($new_lineinfo_fh , $stream )
7903 or _db_warn("Cannot open '$stream' for write");
7904 $LINEINFO = $new_lineinfo_fh;
7905 _autoflush($LINEINFO);
7909 } ## end sub LineInfo
7911 =head1 COMMAND SUPPORT ROUTINES
7913 These subroutines provide functionality for various commands.
7915 =head2 C<list_modules>
7917 For the C<M> command: list modules loaded and their versions.
7918 Essentially just runs through the keys in %INC, picks each package's
7919 C<$VERSION> variable, gets the file name, and formats the information
7924 sub list_modules { # versions
7928 # keys are the "as-loaded" name, values are the fully-qualified path
7929 # to the file itself.
7931 $file = $_; # get the module name
7932 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
7933 s,/,::,g; # change '/' to '::'
7934 s/^perl5db$/DB/; # Special case: debugger
7935 # moves to package DB
7936 s/^Term::ReadLine::readline$/readline/; # simplify readline
7938 # If the package has a $VERSION package global (as all good packages
7939 # should!) decode it and save as partial message.
7940 my $pkg_version = do { no strict 'refs'; ${ $_ . '::VERSION' } };
7941 if ( defined $pkg_version ) {
7942 $version{$file} = "$pkg_version from ";
7945 # Finish up the message with the file the package came from.
7946 $version{$file} .= $INC{$file};
7947 } ## end for (keys %INC)
7949 # Hey, dumpit() formats a hash nicely, so why not use it?
7950 dumpit( $OUT, \%version );
7951 } ## end sub list_modules
7955 Sets up the monster string used to format and print the help.
7957 =head3 HELP MESSAGE FORMAT
7959 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
7960 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
7961 easy to parse and portable, but which still allows the help to be a little
7962 nicer than just plain text.
7964 Essentially, you define the command name (usually marked up with C<< B<> >>
7965 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
7966 newline. The descriptive text can also be marked up in the same way. If you
7967 need to continue the descriptive text to another line, start that line with
7968 just tabs and then enter the marked-up text.
7970 If you are modifying the help text, I<be careful>. The help-string parser is
7971 not very sophisticated, and if you don't follow these rules it will mangle the
7972 help beyond hope until you fix the string.
7976 use vars qw($pre580_help);
7977 use vars qw($pre580_summary);
7981 # XXX: make sure there are tabs between the command and explanation,
7982 # or print_help will screw up your formatting if you have
7983 # eeevil ornaments enabled. This is an insane mess.
7986 Help is currently only available for the new 5.8 command set.
7987 No help is available for the old command set.
7988 We assume you know what you're doing if you switch to it.
7991 B<s> [I<expr>] Single step [in I<expr>].
7992 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
7993 <B<CR>> Repeat last B<n> or B<s> command.
7994 B<r> Return from current subroutine.
7995 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
7996 at the specified position.
7997 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
7998 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
7999 B<l> I<line> List single I<line>.
8000 B<l> I<subname> List first window of lines from subroutine.
8001 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
8002 B<l> List next window of lines.
8003 B<-> List previous window of lines.
8004 B<v> [I<line>] View window around I<line>.
8005 B<.> Return to the executed line.
8006 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
8007 I<filename> may be either the full name of the file, or a regular
8008 expression matching the full file name:
8009 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
8010 Evals (with saved bodies) are considered to be filenames:
8011 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
8012 (in the order of execution).
8013 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
8014 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
8015 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
8016 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
8017 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth).
8018 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
8019 B<b> Sets breakpoint on current line)
8020 B<b> [I<line>] [I<condition>]
8021 Set breakpoint; I<line> defaults to the current execution line;
8022 I<condition> breaks if it evaluates to true, defaults to '1'.
8023 B<b> I<subname> [I<condition>]
8024 Set breakpoint at first line of subroutine.
8025 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
8026 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
8027 B<b> B<postpone> I<subname> [I<condition>]
8028 Set breakpoint at first line of subroutine after
8030 B<b> B<compile> I<subname>
8031 Stop after the subroutine is compiled.
8032 B<B> [I<line>] Delete the breakpoint for I<line>.
8033 B<B> I<*> Delete all breakpoints.
8034 B<a> [I<line>] I<command>
8035 Set an action to be done before the I<line> is executed;
8036 I<line> defaults to the current execution line.
8037 Sequence is: check for breakpoint/watchpoint, print line
8038 if necessary, do action, prompt user if necessary,
8041 B<A> [I<line>] Delete the action for I<line>.
8042 B<A> I<*> Delete all actions.
8043 B<w> I<expr> Add a global watch-expression.
8045 B<W> I<expr> Delete a global watch-expression.
8046 B<W> I<*> Delete all watch-expressions.
8047 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
8048 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
8049 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
8050 B<x> I<expr> Evals expression in list context, dumps the result.
8051 B<m> I<expr> Evals expression in list context, prints methods callable
8052 on the first element of the result.
8053 B<m> I<class> Prints methods callable via the given class.
8054 B<M> Show versions of loaded modules.
8055 B<i> I<class> Prints nested parents of given class.
8056 B<e> Display current thread id.
8057 B<E> Display all thread ids the current one will be identified: <n>.
8058 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8060 B<<> ? List Perl commands to run before each prompt.
8061 B<<> I<expr> Define Perl command to run before each prompt.
8062 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
8063 B<< *> Delete the list of perl commands to run before each prompt.
8064 B<>> ? List Perl commands to run after each prompt.
8065 B<>> I<expr> Define Perl command to run after each prompt.
8066 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
8067 B<>>B< *> Delete the list of Perl commands to run after each prompt.
8068 B<{> I<db_command> Define debugger command to run before each prompt.
8069 B<{> ? List debugger commands to run before each prompt.
8070 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
8071 B<{ *> Delete the list of debugger commands to run before each prompt.
8072 B<$prc> I<number> Redo a previous command (default previous command).
8073 B<$prc> I<-number> Redo number'th-to-last command.
8074 B<$prc> I<pattern> Redo last command that started with I<pattern>.
8075 See 'B<O> I<recallCommand>' too.
8076 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
8081 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
8083 See 'B<O> I<shellBang>' too.
8084 B<source> I<file> Execute I<file> containing debugger commands (may nest).
8085 B<save> I<file> Save current debugger session (actual history) to I<file>.
8086 B<rerun> Rerun session to current position.
8087 B<rerun> I<n> Rerun session to numbered command.
8088 B<rerun> I<-n> Rerun session to number'th-to-last command.
8089 B<H> I<-number> Display last number commands (default all).
8090 B<H> I<*> Delete complete history.
8091 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
8092 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
8093 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarily select()ed as well.
8094 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
8095 I<command> Execute as a perl statement in current package.
8096 B<R> Pure-man-restart of debugger, some of debugger state
8097 and command-line options may be lost.
8098 Currently the following settings are preserved:
8099 history, breakpoints and actions, debugger B<O>ptions
8100 and the following command-line options: I<-w>, I<-I>, I<-e>.
8102 B<o> [I<opt>] ... Set boolean option to true
8103 B<o> [I<opt>B<?>] Query options
8104 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
8105 Set options. Use quotes if spaces in value.
8106 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
8107 I<pager> program for output of \"|cmd\";
8108 I<tkRunning> run Tk while prompting (with ReadLine);
8109 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
8110 I<inhibit_exit> Allows stepping off the end of the script.
8111 I<ImmediateStop> Debugger should stop as early as possible.
8112 I<RemotePort> Remote hostname:port for remote debugging
8113 The following options affect what happens with B<V>, B<X>, and B<x> commands:
8114 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
8115 I<compactDump>, I<veryCompact> change style of array and hash dump;
8116 I<globPrint> whether to print contents of globs;
8117 I<DumpDBFiles> dump arrays holding debugged files;
8118 I<DumpPackages> dump symbol tables of packages;
8119 I<DumpReused> dump contents of \"reused\" addresses;
8120 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
8121 I<bareStringify> Do not print the overload-stringified value;
8122 Other options include:
8123 I<PrintRet> affects printing of return value after B<r> command,
8124 I<frame> affects printing messages on subroutine entry/exit.
8125 I<AutoTrace> affects printing messages on possible breaking points.
8126 I<maxTraceLen> gives max length of evals/args listed in stack trace.
8127 I<ornaments> affects screen appearance of the command line.
8128 I<CreateTTY> bits control attempts to create a new TTY on events:
8129 1: on fork() 2: debugger is started inside debugger
8131 During startup options are initialized from \$ENV{PERLDB_OPTS}.
8132 You can put additional initialization options I<TTY>, I<noTTY>,
8133 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
8134 B<R> after you set them).
8136 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
8137 B<h> Summary of debugger commands.
8138 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
8139 B<h h> Long help for debugger commands
8140 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
8141 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
8142 Set B<\$DB::doccmd> to change viewer.
8144 Type '|h h' for a paged display if this was too hard to read.
8146 "; # Fix balance of vi % matching: }}}}
8148 # note: tabs in the following section are not-so-helpful
8149 $summary = <<"END_SUM";
8150 I<List/search source lines:> I<Control script execution:>
8151 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
8152 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
8153 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
8154 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
8155 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
8156 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
8157 I<Debugger controls:> B<L> List break/watch/actions
8158 B<o> [...] Set debugger options B<t> [I<n>] [I<expr>] Toggle trace [max depth] ][trace expr]
8159 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
8160 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
8161 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
8162 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
8163 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
8164 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
8165 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
8166 B<q> or B<^D> Quit B<R> Attempt a restart
8167 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
8168 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
8169 B<p> I<expr> Print expression (uses script's current package).
8170 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
8171 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
8172 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
8173 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8174 B<e> Display thread id B<E> Display all thread ids.
8175 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
8178 # ')}}; # Fix balance of vi % matching
8180 # and this is really numb...
8183 B<s> [I<expr>] Single step [in I<expr>].
8184 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
8185 B<CR>> Repeat last B<n> or B<s> command.
8186 B<r> Return from current subroutine.
8187 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
8188 at the specified position.
8189 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
8190 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
8191 B<l> I<line> List single I<line>.
8192 B<l> I<subname> List first window of lines from subroutine.
8193 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
8194 B<l> List next window of lines.
8195 B<-> List previous window of lines.
8196 B<w> [I<line>] List window around I<line>.
8197 B<.> Return to the executed line.
8198 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
8199 I<filename> may be either the full name of the file, or a regular
8200 expression matching the full file name:
8201 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
8202 Evals (with saved bodies) are considered to be filenames:
8203 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
8204 (in the order of execution).
8205 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
8206 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
8207 B<L> List all breakpoints and actions.
8208 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
8209 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth) .
8210 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
8211 B<b> [I<line>] [I<condition>]
8212 Set breakpoint; I<line> defaults to the current execution line;
8213 I<condition> breaks if it evaluates to true, defaults to '1'.
8214 B<b> I<subname> [I<condition>]
8215 Set breakpoint at first line of subroutine.
8216 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
8217 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
8218 B<b> B<postpone> I<subname> [I<condition>]
8219 Set breakpoint at first line of subroutine after
8221 B<b> B<compile> I<subname>
8222 Stop after the subroutine is compiled.
8223 B<d> [I<line>] Delete the breakpoint for I<line>.
8224 B<D> Delete all breakpoints.
8225 B<a> [I<line>] I<command>
8226 Set an action to be done before the I<line> is executed;
8227 I<line> defaults to the current execution line.
8228 Sequence is: check for breakpoint/watchpoint, print line
8229 if necessary, do action, prompt user if necessary,
8231 B<a> [I<line>] Delete the action for I<line>.
8232 B<A> Delete all actions.
8233 B<W> I<expr> Add a global watch-expression.
8234 B<W> Delete all watch-expressions.
8235 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
8236 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
8237 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
8238 B<x> I<expr> Evals expression in list context, dumps the result.
8239 B<m> I<expr> Evals expression in list context, prints methods callable
8240 on the first element of the result.
8241 B<m> I<class> Prints methods callable via the given class.
8243 B<<> ? List Perl commands to run before each prompt.
8244 B<<> I<expr> Define Perl command to run before each prompt.
8245 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
8246 B<>> ? List Perl commands to run after each prompt.
8247 B<>> I<expr> Define Perl command to run after each prompt.
8248 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
8249 B<{> I<db_command> Define debugger command to run before each prompt.
8250 B<{> ? List debugger commands to run before each prompt.
8251 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
8252 B<$prc> I<number> Redo a previous command (default previous command).
8253 B<$prc> I<-number> Redo number'th-to-last command.
8254 B<$prc> I<pattern> Redo last command that started with I<pattern>.
8255 See 'B<O> I<recallCommand>' too.
8256 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
8261 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
8263 See 'B<O> I<shellBang>' too.
8264 B<source> I<file> Execute I<file> containing debugger commands (may nest).
8265 B<H> I<-number> Display last number commands (default all).
8266 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
8267 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
8268 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
8269 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
8270 I<command> Execute as a perl statement in current package.
8271 B<v> Show versions of loaded modules.
8272 B<R> Pure-man-restart of debugger, some of debugger state
8273 and command-line options may be lost.
8274 Currently the following settings are preserved:
8275 history, breakpoints and actions, debugger B<O>ptions
8276 and the following command-line options: I<-w>, I<-I>, I<-e>.
8278 B<O> [I<opt>] ... Set boolean option to true
8279 B<O> [I<opt>B<?>] Query options
8280 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
8281 Set options. Use quotes if spaces in value.
8282 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
8283 I<pager> program for output of \"|cmd\";
8284 I<tkRunning> run Tk while prompting (with ReadLine);
8285 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
8286 I<inhibit_exit> Allows stepping off the end of the script.
8287 I<ImmediateStop> Debugger should stop as early as possible.
8288 I<RemotePort> Remote hostname:port for remote debugging
8289 The following options affect what happens with B<V>, B<X>, and B<x> commands:
8290 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
8291 I<compactDump>, I<veryCompact> change style of array and hash dump;
8292 I<globPrint> whether to print contents of globs;
8293 I<DumpDBFiles> dump arrays holding debugged files;
8294 I<DumpPackages> dump symbol tables of packages;
8295 I<DumpReused> dump contents of \"reused\" addresses;
8296 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
8297 I<bareStringify> Do not print the overload-stringified value;
8298 Other options include:
8299 I<PrintRet> affects printing of return value after B<r> command,
8300 I<frame> affects printing messages on subroutine entry/exit.
8301 I<AutoTrace> affects printing messages on possible breaking points.
8302 I<maxTraceLen> gives max length of evals/args listed in stack trace.
8303 I<ornaments> affects screen appearance of the command line.
8304 I<CreateTTY> bits control attempts to create a new TTY on events:
8305 1: on fork() 2: debugger is started inside debugger
8307 During startup options are initialized from \$ENV{PERLDB_OPTS}.
8308 You can put additional initialization options I<TTY>, I<noTTY>,
8309 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
8310 B<R> after you set them).
8312 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
8313 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
8314 B<h h> Summary of debugger commands.
8315 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
8316 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
8317 Set B<\$DB::doccmd> to change viewer.
8319 Type '|h' for a paged display if this was too hard to read.
8321 "; # Fix balance of vi % matching: }}}}
8323 # note: tabs in the following section are not-so-helpful
8324 $pre580_summary = <<"END_SUM";
8325 I<List/search source lines:> I<Control script execution:>
8326 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
8327 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
8328 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
8329 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
8330 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
8331 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
8332 I<Debugger controls:> B<L> List break/watch/actions
8333 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
8334 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
8335 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
8336 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
8337 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
8338 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
8339 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
8340 B<q> or B<^D> Quit B<R> Attempt a restart
8341 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
8342 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
8343 B<p> I<expr> Print expression (uses script's current package).
8344 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
8345 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
8346 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
8347 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8348 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
8351 # ')}}; # Fix balance of vi % matching
8353 } ## end sub sethelp
8355 =head2 C<print_help()>
8357 Most of what C<print_help> does is just text formatting. It finds the
8358 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
8359 terminal control characters to simulate them (courtesy of
8360 C<Term::ReadLine::TermCap>).
8365 my $help_str = shift;
8367 # Restore proper alignment destroyed by eeevil I<> and B<>
8368 # ornaments: A pox on both their houses!
8370 # A help command will have everything up to and including
8371 # the first tab sequence padded into a field 16 (or if indented 20)
8372 # wide. If it's wider than that, an extra space will be added.
8374 ^ # only matters at start of line
8375 ( \040{4} | \t )* # some subcommands are indented
8376 ( < ? # so <CR> works
8377 [BI] < [^\t\n] + ) # find an eeevil ornament
8378 ( \t+ ) # original separation, discarded
8379 ( .* ) # this will now start (no earlier) than
8382 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
8383 my $clean = $command;
8384 $clean =~ s/[BI]<([^>]*)>/$1/g;
8386 # replace with this whole string:
8387 ($leadwhite ? " " x 4 : "")
8389 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
8394 $help_str =~ s{ # handle bold ornaments
8395 B < ( [^>] + | > ) >
8397 $Term::ReadLine::TermCap::rl_term_set[2]
8399 . $Term::ReadLine::TermCap::rl_term_set[3]
8402 $help_str =~ s{ # handle italic ornaments
8403 I < ( [^>] + | > ) >
8405 $Term::ReadLine::TermCap::rl_term_set[0]
8407 . $Term::ReadLine::TermCap::rl_term_set[1]
8411 print {$OUT} $help_str;
8414 } ## end sub print_help
8418 This routine does a lot of gyrations to be sure that the pager is C<less>.
8419 It checks for C<less> masquerading as C<more> and records the result in
8420 C<$fixed_less> so we don't have to go through doing the stats again.
8424 use vars qw($fixed_less);
8427 if ($pager =~ /\bless\b/)
8431 elsif ($pager =~ /\bmore\b/)
8433 # Nope, set to more. See what's out there.
8434 my @st_more = stat('/usr/bin/more');
8435 my @st_less = stat('/usr/bin/less');
8437 # is it really less, pretending to be more?
8441 && $st_more[0] == $st_less[0]
8442 && $st_more[1] == $st_less[1]
8452 # We already know if this is set.
8453 return if $fixed_less;
8455 # changes environment!
8456 # 'r' added so we don't do (slow) stats again.
8457 $fixed_less = 1 if _calc_is_less();
8460 } ## end sub fix_less
8462 =head1 DIE AND WARN MANAGEMENT
8466 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
8467 to debug a debugger problem.
8469 It does its best to report the error that occurred, and then forces the
8470 program, debugger, and everything to die.
8476 # No entry/exit messages.
8479 # No return value prints.
8482 # set the abort signal handling to the default (just terminate).
8483 $SIG{'ABRT'} = 'DEFAULT';
8485 # If we enter the signal handler recursively, kill myself with an
8486 # abort signal (so we just terminate).
8487 kill 'ABRT', $$ if $panic++;
8489 # If we can show detailed info, do so.
8490 if ( defined &Carp::longmess ) {
8492 # Don't recursively enter the warn handler, since we're carping.
8493 local $SIG{__WARN__} = '';
8495 # Skip two levels before reporting traceback: we're skipping
8496 # mydie and confess.
8497 local $Carp::CarpLevel = 2; # mydie + confess
8499 # Tell us all about it.
8500 _db_warn( Carp::longmess("Signal @_") );
8503 # No Carp. Tell us about the signal as best we can.
8506 print $DB::OUT "Got signal @_\n";
8511 } ## end sub diesignal
8515 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
8516 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
8522 # No entry/exit trace.
8525 # No return value printing.
8528 # Turn off warn and die handling to prevent recursive entries to this
8530 local $SIG{__WARN__} = '';
8531 local $SIG{__DIE__} = '';
8533 # Load Carp if we can. If $^S is false (current thing being compiled isn't
8534 # done yet), we may not be able to do a require.
8535 eval { require Carp }
8536 if defined $^S; # If error/warning during compilation,
8537 # require may be broken.
8539 # Use the core warn() unless Carp loaded OK.
8541 "\nCannot print stack trace, load with -MCarp option to see stack" ),
8543 unless defined &Carp::longmess;
8545 # Save the current values of $single and $trace, and then turn them off.
8546 my ( $mysingle, $mytrace ) = ( $single, $trace );
8550 # We can call Carp::longmess without its being "debugged" (which we
8551 # don't want - we just want to use it!). Capture this for later.
8552 my $mess = Carp::longmess(@_);
8554 # Restore $single and $trace to their original values.
8555 ( $single, $trace ) = ( $mysingle, $mytrace );
8557 # Use the debugger's own special way of printing warnings to print
8558 # the stack trace message.
8564 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
8565 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
8566 single stepping and tracing during the call to C<Carp::longmess> to avoid
8567 debugging it - we just want to use it.
8569 If C<dieLevel> is zero, we let the program being debugged handle the
8570 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
8571 the debugger takes over all exception handling, printing a backtrace and
8572 displaying the exception via its C<dbwarn()> routine.
8579 local $SIG{__DIE__} = '';
8580 local $SIG{__WARN__} = '';
8581 if ( $dieLevel > 2 ) {
8582 local $SIG{__WARN__} = \&dbwarn;
8583 _db_warn(@_); # Yell no matter what
8586 if ( $dieLevel < 2 ) {
8587 die @_ if $^S; # in eval propagate
8590 # The code used to check $^S to see if compilation of the current thing
8591 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
8592 eval { require Carp };
8595 "\nCannot print stack trace, load with -MCarp option to see stack" )
8596 unless defined &Carp::longmess;
8598 # We do not want to debug this chunk (automatic disabling works
8599 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
8600 # get the stack trace from Carp::longmess (if possible), restore $signal
8601 # and $trace, and then die with the stack trace.
8602 my ( $mysingle, $mytrace ) = ( $single, $trace );
8608 package Carp; # Do not include us in the list
8609 eval { $mess = Carp::longmess(@_); };
8611 ( $single, $trace ) = ( $mysingle, $mytrace );
8615 =head2 C<warnlevel()>
8617 Set the C<$DB::warnLevel> variable that stores the value of the
8618 C<warnLevel> option. Calling C<warnLevel()> with a positive value
8619 results in the debugger taking over all warning handlers. Setting
8620 C<warnLevel> to zero leaves any warning handlers set up by the program
8621 being debugged in place.
8627 my $prevwarn = $SIG{__WARN__} unless $warnLevel;
8630 $SIG{__WARN__} = \&DB::dbwarn;
8633 $SIG{__WARN__} = $prevwarn;
8635 undef $SIG{__WARN__};
8639 } ## end sub warnLevel
8643 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
8644 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
8645 zero lets you use your own C<die()> handler.
8652 my $prevdie = $SIG{__DIE__} unless $dieLevel;
8656 # Always set it to dbdie() for non-zero values.
8657 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
8659 # No longer exists, so don't try to use it.
8660 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
8662 # If we've finished initialization, mention that stack dumps
8663 # are enabled, If dieLevel is 1, we won't stack dump if we die
8665 print $OUT "Stack dump during die enabled",
8666 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
8669 # XXX This is probably obsolete, given that diehard() is gone.
8670 print $OUT "Dump printed too.\n" if $dieLevel > 2;
8671 } ## end if ($dieLevel)
8673 # Put the old one back if there was one.
8675 $SIG{__DIE__} = $prevdie;
8676 print $OUT "Default die handler restored.\n";
8678 undef $SIG{__DIE__};
8679 print $OUT "Die handler removed.\n";
8683 } ## end sub dieLevel
8685 =head2 C<signalLevel>
8687 Number three in a series: set C<signalLevel> to zero to keep your own
8688 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
8689 takes over and handles them with C<DB::diesignal()>.
8695 my $prevsegv = $SIG{SEGV} unless $signalLevel;
8696 my $prevbus = $SIG{BUS} unless $signalLevel;
8697 $signalLevel = shift;
8699 $SIG{SEGV} = \&DB::diesignal;
8700 $SIG{BUS} = \&DB::diesignal;
8703 $SIG{SEGV} = $prevsegv;
8704 $SIG{BUS} = $prevbus;
8708 } ## end sub signalLevel
8710 =head1 SUBROUTINE DECODING SUPPORT
8712 These subroutines are used during the C<x> and C<X> commands to try to
8713 produce as much information as possible about a code reference. They use
8714 L<Devel::Peek> to try to find the glob in which this code reference lives
8715 (if it does) - this allows us to actually code references which correspond
8716 to named subroutines (including those aliased via glob assignment).
8718 =head2 C<CvGV_name()>
8720 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
8721 via that routine. If this fails, return the reference again (when the
8722 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
8728 my $name = CvGV_name_or_bust($in);
8729 defined $name ? $name : $in;
8732 =head2 C<CvGV_name_or_bust> I<coderef>
8734 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
8735 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
8736 find a glob for this ref.
8738 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
8742 use vars qw($skipCvGV);
8744 sub CvGV_name_or_bust {
8746 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
8747 return unless ref $in;
8748 $in = \&$in; # Hard reference...
8749 eval { require Devel::Peek; 1 } or return;
8750 my $gv = Devel::Peek::CvGV($in) or return;
8751 *$gv{PACKAGE} . '::' . *$gv{NAME};
8752 } ## end sub CvGV_name_or_bust
8756 A utility routine used in various places; finds the file where a subroutine
8757 was defined, and returns that filename and a line-number range.
8759 Tries to use C<@sub> first; if it can't find it there, it tries building a
8760 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
8761 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
8762 this way, it brute-force searches C<%sub>, checking for identical references.
8766 sub _find_sub_helper {
8769 return unless defined &$subr;
8770 my $name = CvGV_name_or_bust($subr);
8772 $data = $sub{$name} if defined $name;
8773 return $data if defined $data;
8776 $subr = \&$subr; # Hard reference
8779 $s = $_, last if $subr eq \&$_;
8794 return ( $sub{$subr} || _find_sub_helper($subr) );
8795 } ## end sub find_sub
8799 A subroutine that uses the utility function C<methods_via> to find all the
8800 methods in the class corresponding to the current reference and in
8809 # Figure out the class - either this is the class or it's a reference
8810 # to something blessed into that class.
8812 $class = ref $class if ref $class;
8816 # Show the methods that this class has.
8817 methods_via( $class, '', 1 );
8819 # Show the methods that UNIVERSAL has.
8820 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
8821 } ## end sub methods
8823 =head2 C<methods_via($class, $prefix, $crawl_upward)>
8825 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
8826 all the parent class methods. C<$class> is the name of the next class to
8827 try; C<$prefix> is the message prefix, which gets built up as we go up the
8828 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
8829 higher in the C<@ISA> tree, 0 if we should stop.
8835 # If we've processed this class already, just quit.
8837 return if $seen{$class}++;
8839 # This is a package that is contributing the methods we're about to print.
8841 my $prepend = $prefix ? "via $prefix: " : '';
8844 # Extract from all the symbols in this class.
8845 my $class_ref = do { no strict "refs"; \%{$class . '::'} };
8846 while (my ($name, $glob) = each %$class_ref) {
8847 # references directly in the symbol table are Proxy Constant
8848 # Subroutines, and are by their very nature defined
8849 # Otherwise, check if the thing is a typeglob, and if it is, it decays
8850 # to a subroutine reference, which can be tested by defined.
8851 # $glob might also be the value -1 (from sub foo;)
8852 # or (say) '$$' (from sub foo ($$);)
8853 # \$glob will be SCALAR in both cases.
8854 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob))
8855 && !$seen{$name}++) {
8856 push @to_print, "$prepend$name\n";
8863 print $DB::OUT $_ foreach sort @to_print;
8866 # If the $crawl_upward argument is false, just quit here.
8867 return unless shift;
8869 # $crawl_upward true: keep going up the tree.
8870 # Find all the classes this one is a subclass of.
8871 my $class_ISA_ref = do { no strict "refs"; \@{"${class}::ISA"} };
8872 for my $name ( @$class_ISA_ref ) {
8874 # Set up the new prefix.
8875 $prepend = $prefix ? $prefix . " -> $name" : $name;
8877 # Crawl up the tree and keep trying to crawl up.
8878 methods_via( $name, $prepend, 1 );
8880 } ## end sub methods_via
8882 =head2 C<setman> - figure out which command to use to show documentation
8884 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8889 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|NetWare)\z/s
8890 ? "man" # O Happy Day!
8891 : "perldoc"; # Alas, poor unfortunates
8894 =head2 C<runman> - run the appropriate command to show documentation
8896 Accepts a man page name; runs the appropriate command to display it (set up
8897 during debugger initialization). Uses C<_db_system()> to avoid mucking up the
8898 program's STDIN and STDOUT.
8905 _db_system("$doccmd $doccmd");
8909 # this way user can override, like with $doccmd="man -Mwhatever"
8910 # or even just "man " to disable the path check.
8911 if ( $doccmd ne 'man' ) {
8912 _db_system("$doccmd $page");
8916 $page = 'perl' if lc($page) eq 'help';
8919 my $man1dir = $Config::Config{man1direxp};
8920 my $man3dir = $Config::Config{man3direxp};
8921 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
8923 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
8924 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
8925 chop $manpath if $manpath;
8927 # harmless if missing, I figure
8928 local $ENV{MANPATH} = $manpath if $manpath;
8929 my $nopathopt = $^O =~ /dunno what goes here/;
8934 # I just *know* there are men without -M
8935 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8940 unless ( $page =~ /^perl\w/ ) {
8941 # Previously the debugger contained a list which it slurped in,
8942 # listing the known "perl" manpages. However, it was out of date,
8943 # with errors both of omission and inclusion. This approach is
8944 # considerably less complex. The failure mode on a butchered
8945 # install is simply that the user has to run man or perldoc
8946 # "manually" with the full manpage name.
8948 # There is a list of $^O values in installperl to determine whether
8949 # the directory is 'pods' or 'pod'. However, we can avoid tight
8950 # coupling to that by simply checking the "non-standard" 'pods'
8952 my $pods = "$Config::Config{privlibexp}/pods";
8953 $pods = "$Config::Config{privlibexp}/pod"
8955 if (-f "$pods/perl$page.pod") {
8956 CORE::system( $doccmd,
8957 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8961 } ## end if (CORE::system($doccmd...
8964 #use Carp; # This did break, left for debugging
8966 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
8968 Because of the way the debugger interface to the Perl core is designed, any
8969 debugger package globals that C<DB::sub()> requires have to be defined before
8970 any subroutines can be called. These are defined in the second C<BEGIN> block.
8972 This block sets things up so that (basically) the world is sane
8973 before the debugger starts executing. We set up various variables that the
8974 debugger has to have set up before the Perl core starts running:
8980 The debugger's own filehandles (copies of STD and STDOUT for now).
8984 Characters for shell escapes, the recall command, and the history command.
8988 The maximum recursion depth.
8992 The size of a C<w> command's window.
8996 The before-this-line context to be printed in a C<v> (view a window around this line) command.
9000 The fact that we're not in a sub at all right now.
9004 The default SIGINT handler for the debugger.
9008 The appropriate value of the flag in C<$^D> that says the debugger is running
9012 The current debugger recursion level
9016 The list of postponed items and the C<$single> stack (XXX define this)
9020 That we want no return values and no subroutine entry/exit trace.
9026 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
9028 use vars qw($db_stop);
9030 BEGIN { # This does not compile, alas. (XXX eh?)
9031 $IN = \*STDIN; # For bugs before DB::OUT has been opened
9032 $OUT = \*STDERR; # For errors before DB::OUT has been opened
9034 # Define characters used by command parsing.
9035 $sh = '!'; # Shell escape (does not work)
9036 $rc = ','; # Recall command (does not work)
9037 @hist = ('?'); # Show history (does not work)
9038 @truehist = (); # Can be saved for replay (per session)
9040 # This defines the point at which you get the 'deep recursion'
9041 # warning. It MUST be defined or the debugger will not load.
9044 # Number of lines around the current one that are shown in the
9048 # How much before-the-current-line context the 'v' command should
9049 # use in calculating the start of the window it will display.
9052 # We're not in any sub yet, but we need this to be a defined value.
9055 # Set up the debugger's interrupt handler. It simply sets a flag
9056 # ($signal) that DB::DB() will check before each command is executed.
9057 $SIG{INT} = \&DB::catch;
9059 # The following lines supposedly, if uncommented, allow the debugger to
9060 # debug itself. Perhaps we can try that someday.
9061 # This may be enabled to debug debugger:
9062 #$warnLevel = 1 unless defined $warnLevel;
9063 #$dieLevel = 1 unless defined $dieLevel;
9064 #$signalLevel = 1 unless defined $signalLevel;
9066 # This is the flag that says "a debugger is running, please call
9067 # DB::DB and DB::sub". We will turn it on forcibly before we try to
9068 # execute anything in the user's context, because we always want to
9070 $db_stop = 0; # Compiler warning ...
9071 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
9073 # This variable records how many levels we're nested in debugging. Used
9074 # Used in the debugger prompt, and in determining whether it's all over or
9076 $level = 0; # Level of recursive debugging
9078 # "Triggers bug (?) in perl if we postpone this until runtime."
9079 # XXX No details on this yet, or whether we should fix the bug instead
9080 # of work around it. Stay tuned.
9083 # Used to track the current stack depth using the auto-stacked-variable
9085 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
9087 # Don't print return values on exiting a subroutine.
9090 # No extry/exit tracing.
9095 BEGIN { $^W = $ini_warn; } # Switch warnings back
9097 =head1 READLINE SUPPORT - COMPLETION FUNCTION
9101 C<readline> support - adds command completion to basic C<readline>.
9103 Returns a list of possible completions to C<readline> when invoked. C<readline>
9104 will print the longest common substring following the text already entered.
9106 If there is only a single possible completion, C<readline> will use it in full.
9108 This code uses C<map> and C<grep> heavily to create lists of possible
9109 completion. Think LISP in this section.
9115 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
9116 # $text is the text to be completed.
9117 # $line is the incoming line typed by the user.
9118 # $start is the start of the text to be completed in the incoming line.
9119 my ( $text, $line, $start ) = @_;
9121 # Save the initial text.
9122 # The search pattern is current package, ::, extract the next qualifier
9123 # Prefix and pack are set to undef.
9124 my ( $itext, $search, $prefix, $pack ) =
9125 ( $text, "^\Q${package}::\E([^:]+)\$" );
9127 =head3 C<b postpone|compile>
9133 Find all the subroutines that might match in this package
9137 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
9141 Include all the rest of the subs that are known
9145 C<grep> out the ones that match the text we have so far
9149 Return this as the list of possible completions
9155 return sort grep /^\Q$text/, ( keys %sub ),
9156 qw(postpone load compile), # subroutines
9157 ( map { /$search/ ? ($1) : () } keys %sub )
9158 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
9162 Get all the possible files from C<@INC> as it currently stands and
9163 select the ones that match the text so far.
9167 return sort grep /^\Q$text/, values %INC # files
9168 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
9170 =head3 C<V> (list variable) and C<m> (list modules)
9172 There are two entry points for these commands:
9174 =head4 Unqualified package names
9176 Get the top-level packages and grab everything that matches the text
9177 so far. For each match, recursively complete the partial packages to
9178 get all possible matching packages. Return this sorted list.
9182 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9183 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
9184 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
9186 =head4 Qualified package names
9188 Take a partially-qualified package and find all subpackages for it
9189 by getting all the subpackages for the package so far, matching all
9190 the subpackages against the text, and discarding all of them which
9191 start with 'main::'. Return this list.
9195 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9196 grep !/^main::/, grep /^\Q$text/,
9197 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () }
9198 do { no strict 'refs'; keys %{ $prefix . '::' } }
9199 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
9200 and $text =~ /^(.*[^:])::?(\w*)$/
9203 =head3 C<f> - switch files
9205 Here, we want to get a fully-qualified filename for the C<f> command.
9210 =item 1. The original source file itself
9212 =item 2. A file from C<@INC>
9214 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
9220 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
9221 # We might possibly want to switch to an eval (which has a "filename"
9222 # like '(eval 9)'), so we may need to clean up the completion text
9223 # before proceeding.
9224 $prefix = length($1) - length($text);
9229 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
9230 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
9231 out of C<%main::>, add the initial source file, and extract the ones that
9232 match the completion text so far.
9237 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
9239 } ## end if ($line =~ /^\|*f\s+(.*)/)
9241 =head3 Subroutine name completion
9243 We look through all of the defined subs (the keys of C<%sub>) and
9244 return both all the possible matches to the subroutine name plus
9245 all the matches qualified to the current package.
9249 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
9250 $text = substr $text, 1;
9252 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
9254 map { /$search/ ? ($1) : () }
9257 } ## end if ((substr $text, 0, ...
9259 =head3 Scalar, array, and hash completion: partially qualified package
9261 Much like the above, except we have to do a little more cleanup:
9265 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
9273 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
9277 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
9283 Figure out the prefix vs. what needs completing.
9287 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
9294 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
9300 map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
9308 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.
9312 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9313 return db_complete( $out[0], $line, $start );
9316 # Return the list of possibles.
9319 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
9325 =head3 Symbol completion: current package or package C<main>.
9329 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
9336 If it's C<main>, delete main to just get C<::> leading.
9340 $pack = ( $package eq 'main' ? '' : $package ) . '::';
9346 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
9350 $prefix = substr $text, 0, 1;
9351 $text = substr $text, 1;
9359 We look for the lexical scope above DB::DB and auto-complete lexical variables
9360 if PadWalker could be loaded.
9364 if (not $text =~ /::/ and eval { require PadWalker } ) {
9367 my @info = caller($level);
9371 last if $info[3] eq 'DB::DB';
9374 my $lexicals = PadWalker::peek_my($level);
9375 push @out, grep /^\Q$prefix$text/, keys %$lexicals;
9383 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
9387 push @out, map "$prefix$_", grep /^\Q$text/,
9388 ( grep /^_?[a-zA-Z]/, keys %$pack ),
9389 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
9393 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
9399 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9400 return db_complete( $out[0], $line, $start );
9403 # Return the list of possibles.
9405 } ## end if ($text =~ /^[\$@%]/)
9409 We use C<option_val()> to look up the current value of the option. If there's
9410 only a single value, we complete the command in such a way that it is a
9411 complete command for setting the option in question. If there are multiple
9412 possible values, we generate a command consisting of the option plus a trailing
9413 question mark, which, if executed, will list the current value of the option.
9417 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
9418 { # Options after space
9419 # We look for the text to be matched in the list of possible options,
9420 # and fetch the current value.
9421 my @out = grep /^\Q$text/, @options;
9422 my $val = option_val( $out[0], undef );
9424 # Set up a 'query option's value' command.
9426 if ( not defined $val or $val =~ /[\n\r]/ ) {
9428 # There's really nothing else we can do.
9431 # We have a value. Create a proper option-setting command.
9432 elsif ( $val =~ /\s/ ) {
9434 # XXX This may be an extraneous variable.
9437 # We'll want to quote the string (because of the embedded
9438 # whtespace), but we want to make sure we don't end up with
9439 # mismatched quote characters. We try several possibilities.
9440 foreach my $l ( split //, qq/\"\'\#\|/ ) {
9442 # If we didn't find this quote character in the value,
9443 # quote it using this quote character.
9444 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
9446 } ## end elsif ($val =~ /\s/)
9448 # Don't need any quotes.
9453 # If there were multiple possible values, return '? ', which
9454 # makes the command into a query command. If there was just one,
9455 # have readline append that.
9456 $rl_attribs->{completer_terminator_character} =
9457 ( @out == 1 ? $out : '? ' );
9459 # Return list of possibilities.
9461 } ## end if ((substr $line, 0, ...
9463 =head3 Filename completion
9465 For entering filenames. We simply call C<readline>'s C<filename_list()>
9466 method with the completion text to get the possible completions.
9470 return $term->filename_list($text); # filenames
9472 } ## end sub db_complete
9474 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
9476 Functions that possibly ought to be somewhere else.
9486 print $OUT "Use 'q' to quit or 'R' to restart. 'h q' for details.\n";
9491 If we have $ini_pids, save it in the environment; else remove it from the
9492 environment. Used by the C<R> (restart) command.
9497 if ( defined($ini_pids) ) {
9498 $ENV{PERLDB_PIDS} = $ini_pids;
9501 delete( $ENV{PERLDB_PIDS} );
9503 } ## end sub clean_ENV
9505 # PERLDBf_... flag names from perl.h
9506 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
9509 %DollarCaretP_flags = (
9510 PERLDBf_SUB => 0x01, # Debug sub enter/exit
9511 PERLDBf_LINE => 0x02, # Keep line #
9512 PERLDBf_NOOPT => 0x04, # Switch off optimizations
9513 PERLDBf_INTER => 0x08, # Preserve more data
9514 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
9515 PERLDBf_SINGLE => 0x20, # Start with single-step on
9516 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
9517 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
9518 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
9519 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
9520 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"}
9521 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO
9523 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger
9524 # doesn't need to set it. It's provided for the benefit of profilers and
9525 # other code analysers.
9527 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
9530 sub parse_DollarCaretP_flags {
9535 foreach my $f ( split /\s*\|\s*/, $flags ) {
9537 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
9540 elsif ( $f =~ /^(\d+)$/ ) {
9543 elsif ( $f =~ /^DEFAULT$/i ) {
9544 $value = $DollarCaretP_flags{PERLDB_ALL};
9547 $f =~ /^(?:PERLDBf_)?(.*)$/i;
9548 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
9549 unless ( defined $value ) {
9551 "Unrecognized \$^P flag '$f'!\n",
9552 "Acceptable flags are: "
9553 . join( ', ', sort keys %DollarCaretP_flags ),
9554 ", and hexadecimal and decimal numbers.\n"
9564 sub expand_DollarCaretP_flags {
9565 my $DollarCaretP = shift;
9568 my $n = ( 1 << $_ );
9569 ( $DollarCaretP & $n )
9570 ? ( $DollarCaretP_flags_r{$n}
9571 || sprintf( '0x%x', $n ) )
9575 return @bits ? join( '|', @bits ) : 0;
9582 Rerun the current session to:
9584 rerun current position
9586 rerun 4 command number 4
9588 rerun -4 current command minus 4 (go back 4 steps)
9590 Whether this always makes sense, in the current context is unknowable, and is
9591 in part left as a useful exercise for the reader. This sub returns the
9592 appropriate arguments to rerun the current session.
9599 pop(@truehist); # strim
9600 unless (defined $truehist[$i]) {
9601 print "Unable to return to non-existent command: $i\n";
9603 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
9604 my @temp = @truehist; # store
9605 push(@DB::typeahead, @truehist); # saved
9606 @truehist = @hist = (); # flush
9607 @args = restart(); # setup
9608 get_list("PERLDB_HIST"); # clean
9609 set_list("PERLDB_HIST", @temp); # reset
9616 Restarting the debugger is a complex operation that occurs in several phases.
9617 First, we try to reconstruct the command line that was used to invoke Perl
9623 # I may not be able to resurrect you, but here goes ...
9625 "Warning: some settings and command-line options may be lost!\n";
9626 my ( @script, @flags, $cl );
9628 # If warn was on before, turn it on again.
9629 push @flags, '-w' if $ini_warn;
9631 # Rebuild the -I flags that were on the initial
9634 push @flags, '-I', $_;
9637 # Turn on taint if it was on before.
9638 push @flags, '-T' if ${^TAINT};
9640 # Arrange for setting the old INC:
9641 # Save the current @init_INC in the environment.
9642 set_list( "PERLDB_INC", @ini_INC );
9644 # If this was a perl one-liner, go to the "file"
9645 # corresponding to the one-liner read all the lines
9646 # out of it (except for the first one, which is going
9647 # to be added back on again when 'perl -d' runs: that's
9648 # the 'require perl5db.pl;' line), and add them back on
9649 # to the command line to be executed.
9651 my $lines = *{$main::{'_<-e'}}{ARRAY};
9652 for ( 1 .. $#$lines ) { # The first line is PERL5DB
9653 chomp( $cl = $lines->[$_] );
9654 push @script, '-e', $cl;
9656 } ## end if ($0 eq '-e')
9658 # Otherwise we just reuse the original name we had
9666 After the command line has been reconstructed, the next step is to save
9667 the debugger's status in environment variables. The C<DB::set_list> routine
9668 is used to save aggregate variables (both hashes and arrays); scalars are
9669 just popped into environment variables directly.
9673 # If the terminal supported history, grab it and
9674 # save that in the environment.
9675 set_list( "PERLDB_HIST",
9676 $term->Features->{getHistory}
9680 # Find all the files that were visited during this
9681 # session (i.e., the debugger had magic hashes
9682 # corresponding to them) and stick them in the environment.
9683 my @had_breakpoints = keys %had_breakpoints;
9684 set_list( "PERLDB_VISITED", @had_breakpoints );
9686 # Save the debugger options we chose.
9687 set_list( "PERLDB_OPT", %option );
9688 # set_list( "PERLDB_OPT", options2remember() );
9690 # Save the break-on-loads.
9691 set_list( "PERLDB_ON_LOAD", %break_on_load );
9695 The most complex part of this is the saving of all of the breakpoints. They
9696 can live in an awful lot of places, and we have to go through all of them,
9697 find the breakpoints, and then save them in the appropriate environment
9698 variable via C<DB::set_list>.
9702 # Go through all the breakpoints and make sure they're
9705 for ( 0 .. $#had_breakpoints ) {
9707 # We were in this file.
9708 my $file = $had_breakpoints[$_];
9710 # Grab that file's magic line hash.
9711 *dbline = $main::{ '_<' . $file };
9713 # Skip out if it doesn't exist, or if the breakpoint
9714 # is in a postponed file (we'll do postponed ones
9716 next unless %dbline or $postponed_file{$file};
9718 # In an eval. This is a little harder, so we'll
9719 # do more processing on that below.
9720 ( push @hard, $file ), next
9721 if $file =~ /^\(\w*eval/;
9723 # XXX I have no idea what this is doing. Yet.
9725 @add = %{ $postponed_file{$file} }
9726 if $postponed_file{$file};
9728 # Save the list of all the breakpoints for this file.
9729 set_list( "PERLDB_FILE_$_", %dbline, @add );
9731 # Serialize the extra data %breakpoints_data hash.
9733 set_list( "PERLDB_FILE_ENABLED_$_",
9734 map { _is_breakpoint_enabled($file, $_) ? 1 : 0 }
9735 sort { $a <=> $b } keys(%dbline)
9737 } ## end for (0 .. $#had_breakpoints)
9739 # The breakpoint was inside an eval. This is a little
9740 # more difficult. XXX and I don't understand it.
9741 foreach my $hard_file (@hard) {
9742 # Get over to the eval in question.
9743 *dbline = $main::{ '_<' . $hard_file };
9744 my $quoted = quotemeta $hard_file;
9746 for my $sub ( keys %sub ) {
9747 if (my ($n1, $n2) = $sub{$sub} =~ /\A$quoted:(\d+)-(\d+)\z/) {
9748 $subs{$sub} = [ $n1, $n2 ];
9753 "No subroutines in $hard_file, ignoring breakpoints.\n";
9756 LINES: foreach my $line ( keys %dbline ) {
9758 # One breakpoint per sub only:
9759 my ( $offset, $found );
9760 SUBS: foreach my $sub ( keys %subs ) {
9762 $subs{$sub}->[1] >= $line # Not after the subroutine
9764 not defined $offset # Not caught
9770 $offset = $line - $subs{$sub}->[0];
9772 $offset = "+$offset";
9775 } ## end if ($subs{$sub}->[1] >=...
9776 } ## end for $sub (keys %subs)
9777 if ( defined $offset ) {
9778 $postponed{$found} =
9779 "break $offset if $dbline{$line}";
9783 ("Breakpoint in ${hard_file}:$line ignored:"
9784 . " after all the subroutines.\n");
9786 } ## end for $line (keys %dbline)
9787 } ## end for (@hard)
9789 # Save the other things that don't need to be
9791 set_list( "PERLDB_POSTPONE", %postponed );
9792 set_list( "PERLDB_PRETYPE", @$pretype );
9793 set_list( "PERLDB_PRE", @$pre );
9794 set_list( "PERLDB_POST", @$post );
9795 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9797 # We are officially restarting.
9798 $ENV{PERLDB_RESTART} = 1;
9800 # We are junking all child debuggers.
9801 delete $ENV{PERLDB_PIDS}; # Restore ini state
9803 # Set this back to the initial pid.
9804 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9808 After all the debugger status has been saved, we take the command we built up
9809 and then return it, so we can C<exec()> it. The debugger will spot the
9810 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9811 from the environment.
9815 # And run Perl again. Add the "-d" flag, all the
9816 # flags we built up, the script (whether a one-liner
9817 # or a file), add on the -emacs flag for a slave editor,
9818 # and then the old arguments.
9820 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9826 =head1 END PROCESSING - THE C<END> BLOCK
9828 Come here at the very end of processing. We want to go into a
9829 loop where we allow the user to enter commands and interact with the
9830 debugger, but we don't want anything else to execute.
9832 First we set the C<$finished> variable, so that some commands that
9833 shouldn't be run after the end of program quit working.
9835 We then figure out whether we're truly done (as in the user entered a C<q>
9836 command, or we finished execution while running nonstop). If we aren't,
9837 we set C<$single> to 1 (causing the debugger to get control again).
9839 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9840 message and returns control to the debugger. Repeat.
9842 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9843 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9844 break, run to completion.).
9849 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9850 $fall_off_end = 1 unless $inhibit_exit;
9852 # Do not stop in at_exit() and destructors on exit:
9853 if ($fall_off_end or $runnonstop) {
9857 DB::fake::at_exit();
9861 =head1 PRE-5.8 COMMANDS
9863 Some of the commands changed function quite a bit in the 5.8 command
9864 realignment, so much so that the old code had to be replaced completely.
9865 Because we wanted to retain the option of being able to go back to the
9866 former command set, we moved the old code off to this section.
9868 There's an awful lot of duplicated code here. We've duplicated the
9869 comments to keep things clear.
9873 Does nothing. Used to I<turn off> commands.
9877 sub cmd_pre580_null {
9882 =head2 Old C<a> command.
9884 This version added actions if you supplied them, and deleted them
9893 # Argument supplied. Add the action.
9894 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9896 # If the line isn't there, use the current line.
9897 my $i = $1 || $line;
9900 # If there is an action ...
9903 # ... but the line isn't breakable, skip it.
9904 if ( $dbline[$i] == 0 ) {
9905 print $OUT "Line $i may not have an action.\n";
9909 # ... and the line is breakable:
9910 # Mark that there's an action in this file.
9911 $had_breakpoints{$filename} |= 2;
9913 # Delete any current action.
9914 $dbline{$i} =~ s/\0[^\0]*//;
9916 # Add the new action, continuing the line as needed.
9917 $dbline{$i} .= "\0" . action($j);
9919 } ## end if (length $j)
9921 # No action supplied.
9924 # Delete the action.
9925 $dbline{$i} =~ s/\0[^\0]*//;
9927 # Mark as having no break or action if nothing's left.
9928 delete $dbline{$i} if $dbline{$i} eq '';
9930 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
9931 } ## end sub cmd_pre580_a
9933 =head2 Old C<b> command
9945 if ( $cmd =~ /^load\b\s*(.*)/ ) {
9951 # b compile|postpone <some sub> [<condition>]
9952 # The interpreter actually traps this one for us; we just put the
9953 # necessary condition in the %postponed hash.
9954 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
9956 # Capture the condition if there is one. Make it true if none.
9957 my $cond = length $3 ? $3 : '1';
9959 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
9960 # if it was 'compile'.
9961 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
9963 # De-Perl4-ify the name - ' separators to ::.
9964 $subname =~ s/\'/::/g;
9966 # Qualify it into the current package unless it's already qualified.
9967 $subname = "${package}::" . $subname
9968 unless $subname =~ /::/;
9970 # Add main if it starts with ::.
9971 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
9973 # Save the break type for this sub.
9974 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
9975 } ## end elsif ($cmd =~ ...
9977 # b <sub name> [<condition>]
9978 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
9980 my $cond = length $2 ? $2 : '1';
9981 cmd_b_sub( $subname, $cond );
9983 # b <line> [<condition>].
9984 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9985 my $i = $1 || $dbline;
9986 my $cond = length $2 ? $2 : '1';
9987 cmd_b_line( $i, $cond );
9989 } ## end sub cmd_pre580_b
9991 =head2 Old C<D> command.
9993 Delete all breakpoints unconditionally.
10000 if ( $cmd =~ /^\s*$/ ) {
10001 print $OUT "Deleting all breakpoints...\n";
10003 # %had_breakpoints lists every file that had at least one
10004 # breakpoint in it.
10006 for $file ( keys %had_breakpoints ) {
10008 # Switch to the desired file temporarily.
10009 local *dbline = $main::{ '_<' . $file };
10014 # For all lines in this file ...
10015 for my $i (1 .. $max) {
10017 # If there's a breakpoint or action on this line ...
10018 if ( defined $dbline{$i} ) {
10020 # ... remove the breakpoint.
10021 $dbline{$i} =~ s/^[^\0]+//;
10022 if ( $dbline{$i} =~ s/^\0?$// ) {
10024 # Remove the entry altogether if no action is there.
10025 delete $dbline{$i};
10027 } ## end if (defined $dbline{$i...
10028 } ## end for my $i (1 .. $max)
10030 # If, after we turn off the "there were breakpoints in this file"
10031 # bit, the entry in %had_breakpoints for this file is zero,
10032 # we should remove this file from the hash.
10033 if ( not $had_breakpoints{$file} &= ~1 ) {
10034 delete $had_breakpoints{$file};
10036 } ## end for $file (keys %had_breakpoints)
10038 # Kill off all the other breakpoints that are waiting for files that
10039 # haven't been loaded yet.
10041 undef %postponed_file;
10042 undef %break_on_load;
10043 } ## end if ($cmd =~ /^\s*$/)
10044 } ## end sub cmd_pre580_D
10046 =head2 Old C<h> command
10048 Print help. Defaults to printing the long-form help; the 5.8 version
10049 prints the summary by default.
10057 # Print the *right* help, long format.
10058 if ( $cmd =~ /^\s*$/ ) {
10059 print_help($pre580_help);
10062 # 'h h' - explicitly-requested summary.
10063 elsif ( $cmd =~ /^h\s*/ ) {
10064 print_help($pre580_summary);
10067 # Find and print a command's help.
10068 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
10069 my $asked = $1; # for proper errmsg
10070 my $qasked = quotemeta($asked); # for searching
10071 # XXX: finds CR but not <CR>
10075 (?:[IB]<) # Optional markup
10076 $qasked # The command name
10083 ( # The command help:
10085 (?:[IB]<) # Optional markup
10086 $qasked # The command name
10087 ([\s\S]*?) # Lines starting with tabs
10091 ) # Line not starting with space
10092 # (Next command's help)
10096 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
10100 print_help("B<$asked> is not a debugger command.\n");
10102 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
10103 } ## end sub cmd_pre580_h
10105 =head2 Old C<W> command
10107 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
10115 # Delete all watch expressions.
10116 if ( $cmd =~ /^$/ ) {
10118 # No watching is going on.
10121 # Kill all the watch expressions and values.
10122 @to_watch = @old_watch = ();
10125 # Add a watch expression.
10126 elsif ( $cmd =~ /^(.*)/s ) {
10128 # add it to the list to be watched.
10129 push @to_watch, $1;
10131 # Get the current value of the expression.
10132 # Doesn't handle expressions returning list values!
10134 # The &-call is here to ascertain the mutability of @_.
10135 my ($val) = &DB::eval;
10136 $val = ( defined $val ) ? "'$val'" : 'undef';
10139 push @old_watch, $val;
10141 # We're watching stuff.
10144 } ## end elsif ($cmd =~ /^(.*)/s)
10145 } ## end sub cmd_pre580_W
10147 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
10149 The debugger used to have a bunch of nearly-identical code to handle
10150 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
10151 C<cmd_prepost> unify all this into one set of code to handle the
10152 appropriate actions.
10154 =head2 C<cmd_pre590_prepost>
10156 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
10157 do something destructive. In pre 5.8 debuggers, the default action was to
10158 delete all the actions.
10162 sub cmd_pre590_prepost {
10164 my $line = shift || '*';
10165 my $dbline = shift;
10167 return cmd_prepost( $cmd, $line, $dbline );
10168 } ## end sub cmd_pre590_prepost
10170 =head2 C<cmd_prepost>
10172 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
10173 Since the lists of actions are all held in arrays that are pointed to by
10174 references anyway, all we have to do is pick the right array reference and
10175 then use generic code to all, delete, or list actions.
10182 # No action supplied defaults to 'list'.
10183 my $line = shift || '?';
10185 # Figure out what to put in the prompt.
10188 # Make sure we have some array or another to address later.
10189 # This means that if for some reason the tests fail, we won't be
10190 # trying to stash actions or delete them from the wrong place.
10193 # < - Perl code to run before prompt.
10194 if ( $cmd =~ /^\</o ) {
10195 $which = 'pre-perl';
10199 # > - Perl code to run after prompt.
10200 elsif ( $cmd =~ /^\>/o ) {
10201 $which = 'post-perl';
10205 # { - first check for properly-balanced braces.
10206 elsif ( $cmd =~ /^\{/o ) {
10207 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
10209 "$cmd is now a debugger command\nuse ';$cmd' if you mean Perl code\n";
10212 # Properly balanced. Pre-prompt debugger actions.
10214 $which = 'pre-debugger';
10217 } ## end elsif ( $cmd =~ /^\{/o )
10219 # Did we find something that makes sense?
10221 print $OUT "Confused by command: $cmd\n";
10228 if ( $line =~ /^\s*\?\s*$/o ) {
10231 # Nothing there. Complain.
10232 print $OUT "No $which actions.\n";
10236 # List the actions in the selected list.
10237 print $OUT "$which commands:\n";
10238 foreach my $action (@$aref) {
10239 print $OUT "\t$cmd -- $action\n";
10242 } ## end if ( $line =~ /^\s*\?\s*$/o)
10244 # Might be a delete.
10246 if ( length($cmd) == 1 ) {
10247 if ( $line =~ /^\s*\*\s*$/o ) {
10249 # It's a delete. Get rid of the old actions in the
10252 print $OUT "All $cmd actions cleared.\n";
10256 # Replace all the actions. (This is a <, >, or {).
10257 @$aref = action($line);
10259 } ## end if ( length($cmd) == 1)
10260 elsif ( length($cmd) == 2 ) {
10262 # Add the action to the line. (This is a <<, >>, or {{).
10263 push @$aref, action($line);
10267 # <<<, >>>>, {{{{{{ ... something not a command.
10269 "Confused by strange length of $which command($cmd)...\n";
10271 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
10273 } ## end sub cmd_prepost
10277 Contains the C<at_exit> routine that the debugger uses to issue the
10278 C<Debugged program terminated ...> message after the program completes. See
10279 the C<END> block documentation for more details.
10286 "Debugged program terminated. Use 'q' to quit or 'R' to restart.";
10289 package DB; # Do not trace this 1; below!