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
519 BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
523 $^V =~ /^v(\d+\.\d+)/;
524 feature->import(":$1");
525 $_initial_cwd = Cwd::getcwd();
528 # Debugger for Perl 5.00x; perl5db.pl patch level:
529 use vars qw($VERSION $header);
531 $VERSION = '1.49_04';
533 $header = "perl5db.pl version $VERSION";
535 =head1 DEBUGGER ROUTINES
539 This function replaces straight C<eval()> inside the debugger; it simplifies
540 the process of evaluating code in the user's context.
542 The code to be evaluated is passed via the package global variable
543 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
545 Before we do the C<eval()>, we preserve the current settings of C<$trace>,
546 C<$single>, C<$^D> and C<$usercontext>. The latter contains the
547 preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
548 user's current package, grabbed when C<DB::DB> got control. This causes the
549 proper context to be used when the eval is actually done. Afterward, we
550 restore C<$trace>, C<$single>, and C<$^D>.
552 Next we need to handle C<$@> without getting confused. We save C<$@> in a
553 local lexical, localize C<$saved[0]> (which is where C<save()> will put
554 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
555 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
556 considered sane by the debugger. If there was an C<eval()> error, we print
557 it on the debugger's output. If C<$onetimedump> is defined, we call
558 C<dumpit> if it's set to 'dump', or C<methods> if it's set to
559 'methods'. Setting it to something else causes the debugger to do the eval
560 but not print the result - handy if you want to do something else with it
561 (the "watch expressions" code does this to get the value of the watch
562 expression but not show it unless it matters).
564 In any case, we then return the list of output from C<eval> to the caller,
565 and unwinding restores the former version of C<$@> in C<@saved> as well
566 (the localization of C<$saved[0]> goes away at the end of this scope).
568 =head3 Parameters and variables influencing execution of DB::eval()
570 C<DB::eval> isn't parameterized in the standard way; this is to keep the
571 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
572 The variables listed below influence C<DB::eval()>'s execution directly.
576 =item C<$evalarg> - the thing to actually be eval'ed
578 =item C<$trace> - Current state of execution tracing
580 =item C<$single> - Current state of single-stepping
582 =item C<$onetimeDump> - what is to be displayed after the evaluation
584 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
588 The following variables are altered by C<DB::eval()> during its execution. They
589 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
593 =item C<@res> - used to capture output from actual C<eval>.
595 =item C<$otrace> - saved value of C<$trace>.
597 =item C<$osingle> - saved value of C<$single>.
599 =item C<$od> - saved value of C<$^D>.
601 =item C<$saved[0]> - saved value of C<$@>.
603 =item $\ - for output of C<$@> if there is an evaluation error.
607 =head3 The problem of lexicals
609 The context of C<DB::eval()> presents us with some problems. Obviously,
610 we want to be 'sandboxed' away from the debugger's internals when we do
611 the eval, but we need some way to control how punctuation variables and
612 debugger globals are used.
614 We can't use local, because the code inside C<DB::eval> can see localized
615 variables; and we can't use C<my> either for the same reason. The code
616 in this routine compromises and uses C<my>.
618 After this routine is over, we don't have user code executing in the debugger's
619 context, so we can use C<my> freely.
623 ############################################## Begin lexical danger zone
625 # 'my' variables used here could leak into (that is, be visible in)
626 # the context that the code being evaluated is executing in. This means that
627 # the code could modify the debugger's variables.
629 # Fiddling with the debugger's context could be Bad. We insulate things as
694 # Used to save @ARGV and extract any debugger-related flags.
697 # Used to prevent multiple entries to diesignal()
698 # (if for instance diesignal() itself dies)
701 # Used to prevent the debugger from running nonstop
705 sub _calc_usercontext {
708 # Cancel strict completely for the evaluated code, so the code
709 # the user evaluates won't be affected by it. (Shlomi Fish)
710 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @DB::saved;'
711 . "package $package;"; # this won't let them modify, alas
716 # 'my' would make it visible from user code
717 # but so does local! --tchrist
718 # Remember: this localizes @DB::res, not @main::res.
722 # Try to keep the user code from messing with us. Save these so that
723 # even if the eval'ed code changes them, we can put them back again.
724 # Needed because the user could refer directly to the debugger's
725 # package globals (and any 'my' variables in this containing scope)
726 # inside the eval(), and we want to try to stay safe.
727 local $otrace = $trace;
728 local $osingle = $single;
731 # Untaint the incoming eval() argument.
732 { ($evalarg) = $evalarg =~ /(.*)/s; }
734 # $usercontext built in DB::DB near the comment
735 # "set up the context for DB::eval ..."
736 # Evaluate and save any results.
737 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
739 # Restore those old values.
745 # Save the current value of $@, and preserve it in the debugger's copy
746 # of the saved precious globals.
749 # Since we're only saving $@, we only have to localize the array element
750 # that it will be stored in.
751 local $saved[0]; # Preserve the old value of $@
754 # Now see whether we need to report an error back to the user.
760 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
761 # are package globals.
762 elsif ($onetimeDump) {
763 if ( $onetimeDump eq 'dump' ) {
764 local $option{dumpDepth} = $onetimedumpDepth
765 if defined $onetimedumpDepth;
766 dumpit( $OUT, \@res );
768 elsif ( $onetimeDump eq 'methods' ) {
771 } ## end elsif ($onetimeDump)
775 ############################################## End lexical danger zone
777 # After this point it is safe to introduce lexicals.
778 # The code being debugged will be executing in its own context, and
779 # can't see the inside of the debugger.
781 # However, one should not overdo it: leave as much control from outside as
782 # possible. If you make something a lexical, it's not going to be addressable
783 # from outside the debugger even if you know its name.
785 # This file is automatically included if you do perl -d.
786 # It's probably not useful to include this yourself.
788 # Before venturing further into these twisty passages, it is
789 # wise to read the perldebguts man page or risk the ire of dragons.
791 # (It should be noted that perldebguts will tell you a lot about
792 # the underlying mechanics of how the debugger interfaces into the
793 # Perl interpreter, but not a lot about the debugger itself. The new
794 # comments in this code try to address this problem.)
796 # Note that no subroutine call is possible until &DB::sub is defined
797 # (for subroutines defined outside of the package DB). In fact the same is
798 # true if $deep is not defined.
800 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
802 # modified Perl debugger, to be run from Emacs in perldb-mode
803 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
804 # Johan Vromans -- upgrade to 4.0 pl 10
805 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
806 ########################################################################
808 =head1 DEBUGGER INITIALIZATION
810 The debugger starts up in phases.
814 First, it initializes the environment it wants to run in: turning off
815 warnings during its own compilation, defining variables which it will need
816 to avoid warnings later, setting itself up to not exit when the program
817 terminates, and defaulting to printing return values for the C<r> command.
821 # Needed for the statement after exec():
823 # This BEGIN block is simply used to switch off warnings during debugger
824 # compilation. Probably it would be better practice to fix the warnings,
825 # but this is how it's done at the moment.
830 } # Switch compilation warnings off until another BEGIN.
832 local ($^W) = 0; # Switch run-time warnings off during init.
834 =head2 THREADS SUPPORT
836 If we are running under a threaded Perl, we require threads and threads::shared
837 if the environment variable C<PERL5DB_THREADED> is set, to enable proper
838 threaded debugger control. C<-dt> can also be used to set this.
840 Each new thread will be announced and the debugger prompt will always inform
841 you of each new thread created. It will also indicate the thread id in which
842 we are currently running within the prompt like this:
846 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
847 command prompt. The prompt will show: C<[0]> when running under threads, but
848 not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
850 While running under threads, when you set or delete a breakpoint (etc.), this
851 will apply to all threads, not just the currently running one. When you are
852 in a currently executing thread, you will stay there until it completes. With
853 the current implementation it is not currently possible to hop from one thread
856 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
858 Note that threading support was built into the debugger as of Perl version
859 C<5.8.6> and debugger version C<1.2.8>.
864 # ensure we can share our non-threaded variables or no-op
865 if ($ENV{PERL5DB_THREADED}) {
867 require threads::shared;
868 import threads::shared qw(share);
872 print "Threads support enabled\n";
875 *share = sub(\[$@%]) {};
879 # These variables control the execution of 'dumpvar.pl'.
894 # used to control die() reporting in diesignal()
897 use vars qw($CarpLevel);
900 # without threads, $filename is not defined until DB::DB is called
901 share($main::{'_<'.$filename}) if defined $filename;
903 # Command-line + PERLLIB:
904 # Save the contents of @INC before they are modified elsewhere.
907 # This was an attempt to clear out the previous values of various
908 # trapped errors. Apparently it didn't help. XXX More info needed!
909 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
911 # We set these variables to safe values. We don't want to blindly turn
912 # off warnings, because other packages may still want them.
913 $trace = $signal = $single = 0; # Uninitialized warning suppression
914 # (local $^W cannot help - other packages!).
916 # Default to not exiting when program finishes; print the return
917 # value when the 'r' command is used to return from a subroutine.
918 $inhibit_exit = $option{PrintRet} = 1;
920 use vars qw($trace_to_depth);
922 # Default to 1E9 so it won't be limited to a certain recursion depth.
923 $trace_to_depth = 1E9;
925 =head1 OPTION PROCESSING
927 The debugger's options are actually spread out over the debugger itself and
928 C<dumpvar.pl>; some of these are variables to be set, while others are
929 subs to be called with a value. To try to make this a little easier to
930 manage, the debugger uses a few data structures to define what options
931 are legal and how they are to be processed.
933 First, the C<@options> array defines the I<names> of all the options that
939 CommandSet HistFile HistSize
940 hashDepth arrayDepth dumpDepth
941 DumpDBFiles DumpPackages DumpReused
942 compactDump veryCompact quote
943 HighBit undefPrint globPrint
944 PrintRet UsageOnly frame
946 ReadLine NonStop LineInfo
947 maxTraceLen recallCommand ShellBang
948 pager tkRunning ornaments
949 signalLevel warnLevel dieLevel
950 inhibit_exit ImmediateStop bareStringify
951 CreateTTY RemotePort windowSize
955 @RememberOnROptions = qw(DollarCaretP);
959 Second, C<optionVars> lists the variables that each option uses to save its
964 use vars qw(%optionVars);
967 hashDepth => \$dumpvar::hashDepth,
968 arrayDepth => \$dumpvar::arrayDepth,
969 CommandSet => \$CommandSet,
970 DumpDBFiles => \$dumpvar::dumpDBFiles,
971 DumpPackages => \$dumpvar::dumpPackages,
972 DumpReused => \$dumpvar::dumpReused,
973 HighBit => \$dumpvar::quoteHighBit,
974 undefPrint => \$dumpvar::printUndef,
975 globPrint => \$dumpvar::globPrint,
976 UsageOnly => \$dumpvar::usageOnly,
977 CreateTTY => \$CreateTTY,
978 bareStringify => \$dumpvar::bareStringify,
980 AutoTrace => \$trace,
981 inhibit_exit => \$inhibit_exit,
982 maxTraceLen => \$maxtrace,
983 ImmediateStop => \$ImmediateStop,
984 RemotePort => \$remoteport,
985 windowSize => \$window,
986 HistFile => \$histfile,
987 HistSize => \$histsize,
992 Third, C<%optionAction> defines the subroutine to be called to process each
997 use vars qw(%optionAction);
1000 compactDump => \&dumpvar::compactDump,
1001 veryCompact => \&dumpvar::veryCompact,
1002 quote => \&dumpvar::quote,
1005 ReadLine => \&ReadLine,
1006 NonStop => \&NonStop,
1007 LineInfo => \&LineInfo,
1008 recallCommand => \&recallCommand,
1009 ShellBang => \&shellBang,
1011 signalLevel => \&signalLevel,
1012 warnLevel => \&warnLevel,
1013 dieLevel => \&dieLevel,
1014 tkRunning => \&tkRunning,
1015 ornaments => \&ornaments,
1016 RemotePort => \&RemotePort,
1017 DollarCaretP => \&DollarCaretP,
1022 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1027 # Note that this list is not complete: several options not listed here
1028 # actually require that dumpvar.pl be loaded for them to work, but are
1029 # not in the table. A subsequent patch will correct this problem; for
1030 # the moment, we're just recommenting, and we are NOT going to change
1032 use vars qw(%optionRequire);
1035 compactDump => 'dumpvar.pl',
1036 veryCompact => 'dumpvar.pl',
1037 quote => 'dumpvar.pl',
1042 There are a number of initialization-related variables which can be set
1043 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1044 variable. These are:
1048 =item C<$rl> - readline control XXX needs more explanation
1050 =item C<$warnLevel> - whether or not debugger takes over warning handling
1052 =item C<$dieLevel> - whether or not debugger takes over die handling
1054 =item C<$signalLevel> - whether or not debugger takes over signal handling
1056 =item C<$pre> - preprompt actions (array reference)
1058 =item C<$post> - postprompt actions (array reference)
1062 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1064 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1070 # These guys may be defined in $ENV{PERL5DB} :
1071 $rl = 1 unless defined $rl;
1072 $warnLevel = 1 unless defined $warnLevel;
1073 $dieLevel = 1 unless defined $dieLevel;
1074 $signalLevel = 1 unless defined $signalLevel;
1075 $pre = [] unless defined $pre;
1076 $post = [] unless defined $post;
1077 $pretype = [] unless defined $pretype;
1078 $CreateTTY = 3 unless defined $CreateTTY;
1079 $CommandSet = '580' unless defined $CommandSet;
1084 share($signalLevel);
1094 The default C<die>, C<warn>, and C<signal> handlers are set up.
1098 warnLevel($warnLevel);
1099 dieLevel($dieLevel);
1100 signalLevel($signalLevel);
1104 The pager to be used is needed next. We try to get it from the
1105 environment first. If it's not defined there, we try to find it in
1106 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1107 then call the C<pager()> function to save the pager name.
1111 # This routine makes sure $pager is set up so that '|' can use it.
1114 # If PAGER is defined in the environment, use it.
1118 # If not, see if Config.pm defines it.
1119 : eval { require Config }
1120 && defined $Config::Config{pager}
1121 ? $Config::Config{pager}
1123 # If not, fall back to 'more'.
1126 unless defined $pager;
1130 We set up the command to be used to access the man pages, the command
1131 recall character (C<!> unless otherwise defined) and the shell escape
1132 character (C<!> unless otherwise defined). Yes, these do conflict, and
1133 neither works in the debugger at the moment.
1139 # Set up defaults for command recall and shell escape (note:
1140 # these currently don't work in linemode debugging).
1141 recallCommand("!") unless defined $prc;
1142 shellBang("!") unless defined $psh;
1146 We then set up the gigantic string containing the debugger help.
1147 We also set the limit on the number of arguments we'll display during a
1154 # If we didn't get a default for the length of eval/stack trace args,
1156 $maxtrace = 400 unless defined $maxtrace;
1158 =head2 SETTING UP THE DEBUGGER GREETING
1160 The debugger I<greeting> helps to inform the user how many debuggers are
1161 running, and whether the current debugger is the primary or a child.
1163 If we are the primary, we just hang onto our pid so we'll have it when
1164 or if we start a child debugger. If we are a child, we'll set things up
1165 so we'll have a unique greeting and so the parent will give us our own
1168 We save the current contents of the C<PERLDB_PIDS> environment variable
1169 because we mess around with it. We'll also need to hang onto it because
1170 we'll need it if we restart.
1172 Child debuggers make a label out of the current PID structure recorded in
1173 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1174 yet so the parent will give them one later via C<resetterm()>.
1178 # Save the current contents of the environment; we're about to
1179 # much with it. We'll need this if we have to restart.
1180 use vars qw($ini_pids);
1181 $ini_pids = $ENV{PERLDB_PIDS};
1183 use vars qw ($pids $term_pid);
1185 if ( defined $ENV{PERLDB_PIDS} ) {
1187 # We're a child. Make us a label out of the current PID structure
1188 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1189 # a term yet so the parent will give us one later via resetterm().
1191 my $env_pids = $ENV{PERLDB_PIDS};
1192 $pids = "[$env_pids]";
1194 # Unless we are on OpenVMS, all programs under the DCL shell run under
1197 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1201 $ENV{PERLDB_PIDS} .= "->$$";
1205 } ## end if (defined $ENV{PERLDB_PIDS...
1208 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1209 # child debugger, and mark us as the parent, so we'll know to set up
1210 # more TTY's is we have to.
1211 $ENV{PERLDB_PIDS} = "$$";
1216 use vars qw($pidprompt);
1219 # Sets up $emacs as a synonym for $slave_editor.
1220 our ($slave_editor);
1221 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1223 =head2 READING THE RC FILE
1225 The debugger will read a file of initialization options if supplied. If
1226 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1230 # As noted, this test really doesn't check accurately that the debugger
1231 # is running at a terminal or not.
1233 use vars qw($rcfile);
1235 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1236 # this is the wrong metric!
1237 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
1242 The debugger does a safety test of the file to be read. It must be owned
1243 either by the current user or root, and must only be writable by the owner.
1247 # This wraps a safety test around "do" to read and evaluate the init file.
1249 # This isn't really safe, because there's a race
1250 # between checking and opening. The solution is to
1251 # open and fstat the handle, but then you have to read and
1252 # eval the contents. But then the silly thing gets
1253 # your lexical scope, which is unfortunate at best.
1257 # Just exactly what part of the word "CORE::" don't you understand?
1258 local $SIG{__WARN__};
1259 local $SIG{__DIE__};
1261 unless ( is_safe_file($file) ) {
1262 CORE::warn <<EO_GRIPE;
1263 perldb: Must not source insecure rcfile $file.
1264 You or the superuser must be the owner, and it must not
1265 be writable by anyone but its owner.
1268 } ## end unless (is_safe_file($file...
1271 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1272 } ## end sub safe_do
1274 # This is the safety test itself.
1276 # Verifies that owner is either real user or superuser and that no
1277 # one but owner may write to it. This function is of limited use
1278 # when called on a path instead of upon a handle, because there are
1279 # no guarantees that filename (by dirent) whose file (by ino) is
1280 # eventually accessed is the same as the one tested.
1281 # Assumes that the file's existence is not in doubt.
1284 stat($path) || return; # mysteriously vaporized
1285 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1287 return 0 if $uid != 0 && $uid != $<;
1288 return 0 if $mode & 022;
1290 } ## end sub is_safe_file
1292 # If the rcfile (whichever one we decided was the right one to read)
1293 # exists, we safely do it.
1295 safe_do("./$rcfile");
1298 # If there isn't one here, try the user's home directory.
1299 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1300 safe_do("$ENV{HOME}/$rcfile");
1303 # Else try the login directory.
1304 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1305 safe_do("$ENV{LOGDIR}/$rcfile");
1308 # If the PERLDB_OPTS variable has options in it, parse those out next.
1309 if ( defined $ENV{PERLDB_OPTS} ) {
1310 parse_options( $ENV{PERLDB_OPTS} );
1315 The last thing we do during initialization is determine which subroutine is
1316 to be used to obtain a new terminal when a new debugger is started. Right now,
1317 the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
1322 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1323 # Works if you're running an xterm or xterm-like window, or you're on
1324 # OS/2, or on Mac OS X. This may need some expansion.
1326 if (not defined &get_fork_TTY) # only if no routine exists
1328 if ( defined $remoteport ) {
1329 # Expect an inetd-like server
1330 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1332 elsif (defined $ENV{TERM} # If we know what kind
1333 # of terminal this is,
1334 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1335 and defined $ENV{DISPLAY} # and what display it's on,
1338 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1340 elsif ( $ENV{TMUX} ) {
1341 *get_fork_TTY = \&tmux_get_fork_TTY;
1343 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1344 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1346 elsif ( $^O eq 'darwin' # If this is Mac OS X
1347 and defined $ENV{TERM_PROGRAM} # and we're running inside
1348 and $ENV{TERM_PROGRAM}
1349 eq 'Apple_Terminal' # Terminal.app
1352 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1354 } ## end if (not defined &get_fork_TTY...
1356 # untaint $^O, which may have been tainted by the last statement.
1357 # see bug [perl #24674]
1361 # Here begin the unreadable code. It needs fixing.
1363 =head2 RESTART PROCESSING
1365 This section handles the restart command. When the C<R> command is invoked, it
1366 tries to capture all of the state it can into environment variables, and
1367 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1368 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1369 the R command stuffed into the environment variables.
1371 PERLDB_RESTART - flag only, contains no restart data itself.
1372 PERLDB_HIST - command history, if it's available
1373 PERLDB_ON_LOAD - breakpoints set by the rc file
1374 PERLDB_POSTPONE - subs that have been loaded/not executed,
1376 PERLDB_VISITED - files that had breakpoints
1377 PERLDB_FILE_... - breakpoints for a file
1378 PERLDB_OPT - active options
1379 PERLDB_INC - the original @INC
1380 PERLDB_PRETYPE - preprompt debugger actions
1381 PERLDB_PRE - preprompt Perl code
1382 PERLDB_POST - post-prompt Perl code
1383 PERLDB_TYPEAHEAD - typeahead captured by readline()
1385 We chug through all these variables and plug the values saved in them
1386 back into the appropriate spots in the debugger.
1390 use vars qw(%postponed_file @typeahead);
1392 our (@hist, @truehist);
1394 sub _restore_shared_globals_after_restart
1396 @hist = get_list('PERLDB_HIST');
1397 %break_on_load = get_list("PERLDB_ON_LOAD");
1398 %postponed = get_list("PERLDB_POSTPONE");
1402 share(%break_on_load);
1406 sub _restore_breakpoints_and_actions {
1408 my @had_breakpoints = get_list("PERLDB_VISITED");
1410 for my $file_idx ( 0 .. $#had_breakpoints ) {
1411 my $filename = $had_breakpoints[$file_idx];
1412 my %pf = get_list("PERLDB_FILE_$file_idx");
1413 $postponed_file{ $filename } = \%pf if %pf;
1414 my @lines = sort {$a <=> $b} keys(%pf);
1415 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1416 for my $line_idx (0 .. $#lines) {
1417 _set_breakpoint_enabled_status(
1420 ($enabled_statuses[$line_idx] ? 1 : ''),
1428 sub _restore_options_after_restart
1430 my %options_map = get_list("PERLDB_OPT");
1432 while ( my ( $opt, $val ) = each %options_map ) {
1433 $val =~ s/[\\\']/\\$1/g;
1434 parse_options("$opt'$val'");
1440 sub _restore_globals_after_restart
1442 # restore original @INC
1443 @INC = get_list("PERLDB_INC");
1446 # return pre/postprompt actions and typeahead buffer
1447 $pretype = [ get_list("PERLDB_PRETYPE") ];
1448 $pre = [ get_list("PERLDB_PRE") ];
1449 $post = [ get_list("PERLDB_POST") ];
1450 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1456 if ( exists $ENV{PERLDB_RESTART} ) {
1458 # We're restarting, so we don't need the flag that says to restart anymore.
1459 delete $ENV{PERLDB_RESTART};
1462 _restore_shared_globals_after_restart();
1464 _restore_breakpoints_and_actions();
1467 _restore_options_after_restart();
1469 _restore_globals_after_restart();
1470 } ## end if (exists $ENV{PERLDB_RESTART...
1472 =head2 SETTING UP THE TERMINAL
1474 Now, we'll decide how the debugger is going to interact with the user.
1475 If there's no TTY, we set the debugger to run non-stop; there's not going
1476 to be anyone there to enter commands.
1480 use vars qw($notty $console $tty $LINEINFO);
1481 use vars qw($lineinfo $doccmd);
1485 # Local autoflush to avoid rt#116769,
1486 # as calling IO::File methods causes an unresolvable loop
1487 # that results in debugger failure.
1489 my $o = select($_[0]);
1501 If there is a TTY, we have to determine who it belongs to before we can
1502 proceed. If this is a slave editor or graphical debugger (denoted by
1503 the first command-line switch being '-emacs'), we shift this off and
1504 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1510 # Is Perl being run from a slave editor or graphical debugger?
1511 # If so, don't use readline, and set $slave_editor = 1.
1512 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1517 #require Term::ReadLine;
1521 We then determine what the console should be on various systems:
1525 =item * Cygwin - We use C<stdin> instead of a separate device.
1529 if ( $^O eq 'cygwin' ) {
1531 # /dev/tty is binary. use stdin for textmode
1535 =item * Unix - use F</dev/tty>.
1539 elsif ( -e "/dev/tty" ) {
1540 $console = "/dev/tty";
1543 =item * Windows or MSDOS - use C<con>.
1547 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1551 =item * AmigaOS - use C<CONSOLE:>.
1555 elsif ( $^O eq 'amigaos' ) {
1556 $console = "CONSOLE:";
1559 =item * VMS - use C<sys$command>.
1563 elsif ($^O eq 'VMS') {
1564 $console = 'sys$command';
1570 _db_warn("Can't figure out your console, using stdin");
1578 Several other systems don't use a specific console. We C<undef $console>
1579 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1580 with a slave editor).
1584 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1586 # /dev/tty is binary. use stdin for textmode
1590 if ( $^O eq 'NetWare' ) {
1592 # /dev/tty is binary. use stdin for textmode
1596 # In OS/2, we need to use STDIN to get textmode too, even though
1597 # it pretty much looks like Unix otherwise.
1598 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1605 If there is a TTY hanging around from a parent, we use that as the console.
1609 $console = $tty if defined $tty;
1611 =head2 SOCKET HANDLING
1613 The debugger is capable of opening a socket and carrying out a debugging
1614 session over the socket.
1616 If C<RemotePort> was defined in the options, the debugger assumes that it
1617 should try to start a debugging session on that port. It builds the socket
1618 and then tries to connect the input and output filehandles to it.
1622 # Handle socket stuff.
1624 if ( defined $remoteport ) {
1626 # If RemotePort was defined in the options, connect input and output
1628 $IN = $OUT = connect_remoteport();
1629 } ## end if (defined $remoteport)
1633 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1634 this is probably a situation where multiple debuggers are running (for example,
1635 a backticked command that starts up another debugger). We create a new IN and
1636 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1644 # Two debuggers running (probably a system or a backtick that invokes
1645 # the debugger itself under the running one). create a new IN and OUT
1646 # filehandle, and do the necessary mojo to create a new tty if we
1647 # know how, and we can.
1648 create_IN_OUT(4) if $CreateTTY & 4;
1651 # If we have a console, check to see if there are separate ins and
1652 # outs to open. (They are assumed identical if not.)
1654 my ( $i, $o ) = split /,/, $console;
1655 $o = $i unless defined $o;
1657 # read/write on in, or just read, or read on STDIN.
1659 || open( IN, "<$i" )
1660 || open( IN, "<&STDIN" );
1662 # read/write/create/clobber out, or write/create/clobber out,
1663 # or merge with STDERR, or merge with STDOUT.
1665 || open( OUT, ">$o" )
1666 || open( OUT, ">&STDERR" )
1667 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1669 } ## end if ($console)
1670 elsif ( not defined $console ) {
1672 # No console. Open STDIN.
1673 open( IN, "<&STDIN" );
1675 # merge with STDERR, or with STDOUT.
1676 open( OUT, ">&STDERR" )
1677 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1678 $console = 'STDIN/OUT';
1679 } ## end elsif (not defined $console)
1681 # Keep copies of the filehandles so that when the pager runs, it
1682 # can close standard input without clobbering ours.
1683 if ($console or (not defined($console))) {
1687 } ## end elsif (from if(defined $remoteport))
1689 # Unbuffer DB::OUT. We need to see responses right away.
1692 # Line info goes to debugger output unless pointed elsewhere.
1693 # Pointing elsewhere makes it possible for slave editors to
1694 # keep track of file and position. We have both a filehandle
1695 # and a I/O description to keep track of.
1696 $LINEINFO = $OUT unless defined $LINEINFO;
1697 $lineinfo = $console unless defined $lineinfo;
1698 # share($LINEINFO); # <- unable to share globs
1703 To finish initialization, we show the debugger greeting,
1704 and then call the C<afterinit()> subroutine if there is one.
1708 # Show the debugger greeting.
1709 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1710 unless ($runnonstop) {
1713 if ( $term_pid eq '-1' ) {
1714 print $OUT "\nDaughter DB session started...\n";
1717 print $OUT "\nLoading DB routines from $header\n";
1720 $slave_editor ? "enabled" : "available", ".\n"
1723 "\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
1724 } ## end else [ if ($term_pid eq '-1')
1725 } ## end unless ($runnonstop)
1726 } ## end else [ if ($notty)
1728 # XXX This looks like a bug to me.
1729 # Why copy to @ARGS and then futz with @args?
1732 # Make sure backslashes before single quotes are stripped out, and
1733 # keep args unless they are numeric (XXX why?)
1734 # s/\'/\\\'/g; # removed while not justified understandably
1735 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1738 # If there was an afterinit() sub defined, call it. It will get
1739 # executed in our scope, so it can fiddle with debugger globals.
1740 if ( defined &afterinit ) { # May be defined in $rcfile
1744 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1745 use vars qw($I_m_init);
1749 ############################################################ Subroutines
1755 This gigantic subroutine is the heart of the debugger. Called before every
1756 statement, its job is to determine if a breakpoint has been reached, and
1757 stop if so; read commands from the user, parse them, and execute
1758 them, and then send execution off to the next statement.
1760 Note that the order in which the commands are processed is very important;
1761 some commands earlier in the loop will actually alter the C<$cmd> variable
1762 to create other commands to be executed later. This is all highly I<optimized>
1763 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1764 see what's happening in any given command.
1768 # $cmd cannot be an our() variable unfortunately (possible perl bug?).
1798 sub _DB__determine_if_we_should_break
1800 # if we have something here, see if we should break.
1801 # $stop is lexical and local to this block - $action on the other hand
1806 && _is_breakpoint_enabled($filename, $line)
1807 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1810 # Stop if the stop criterion says to just stop.
1811 if ( $stop eq '1' ) {
1815 # It's a conditional stop; eval it in the user's context and
1816 # see if we should stop. If so, remove the one-time sigil.
1818 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1819 # The &-call is here to ascertain the mutability of @_.
1821 # If the breakpoint is temporary, then delete its enabled status.
1822 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1823 _cancel_breakpoint_temp_enabled_status($filename, $line);
1826 } ## end if ($dbline{$line} && ...
1829 sub _DB__is_finished {
1830 if ($finished and $level <= 1) {
1839 sub _DB__read_next_cmd
1843 # We have a terminal, or can get one ...
1848 # ... and it belongs to this PID or we get one for this PID ...
1849 if ($term_pid != $$) {
1853 # ... and we got a line of command input ...
1854 $cmd = DB::readline(
1855 "$pidprompt $tid DB"
1858 . ( '>' x $level ) . " "
1861 return defined($cmd);
1864 sub _DB__trim_command_and_return_first_component {
1867 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1868 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1870 my ($verb, $args) = $cmd =~ m{\A(\S*)\s*(.*)}s;
1872 $obj->cmd_verb($verb);
1873 $obj->cmd_args($args);
1878 sub _DB__handle_f_command {
1881 if ($file = $obj->cmd_args) {
1882 # help for no arguments (old-style was return from sub).
1885 "The old f command is now the r command.\n"; # hint
1886 print $OUT "The new f command switches filenames.\n";
1888 } ## end if (!$file)
1890 # if not in magic file list, try a close match.
1891 if ( !defined $main::{ '_<' . $file } ) {
1892 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
1894 $try = substr( $try, 2 );
1895 print $OUT "Choosing $try matching '$file':\n";
1898 } ## end if (($try) = grep(m#^_<.*$file#...
1899 } ## end if (!defined $main::{ ...
1901 # If not successfully switched now, we failed.
1902 if ( !defined $main::{ '_<' . $file } ) {
1903 print $OUT "No file matching '$file' is loaded.\n";
1907 # We switched, so switch the debugger internals around.
1908 elsif ( $file ne $filename ) {
1909 *dbline = $main::{ '_<' . $file };
1914 } ## end elsif ($file ne $filename)
1916 # We didn't switch; say we didn't.
1918 print $OUT "Already in $file.\n";
1926 sub _DB__handle_dot_command {
1930 if ($obj->_is_full('.')) {
1931 $incr = -1; # stay at current line
1933 # Reset everything to the old location.
1935 $filename = $filename_ini;
1936 *dbline = $main::{ '_<' . $filename };
1940 print_lineinfo($obj->position());
1947 sub _DB__handle_y_command {
1950 if (my ($match_level, $match_vars)
1951 = $obj->cmd_args =~ /\A(?:(\d*)\s*(.*))?\z/) {
1953 # See if we've got the necessary support.
1954 if (!eval { require PadWalker; PadWalker->VERSION(0.08) }) {
1958 ? "PadWalker module not found - please install\n"
1964 # Load up dumpvar if we don't have it. If we can, that is.
1965 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
1966 defined &main::dumpvar
1967 or print $OUT "dumpvar.pl not available.\n"
1970 # Got all the modules we need. Find them and print them.
1971 my @vars = split( ' ', $match_vars || '' );
1974 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 2 ) };
1976 # Oops. Can't find it.
1983 # Show the desired vars with dumplex().
1984 my $savout = select($OUT);
1986 # Have dumplex dump the lexicals.
1987 foreach my $key (sort keys %$h) {
1988 dumpvar::dumplex( $key, $h->{$key},
1989 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
1997 sub _DB__handle_c_command {
2000 my $i = $obj->cmd_args;
2002 if ($i =~ m#\A[\w:]*\z#) {
2004 # Hey, show's over. The debugged program finished
2005 # executing already.
2006 next CMD if _DB__is_finished();
2008 # Capture the place to put a one-time break.
2011 # Probably not needed, since we finish an interactive
2012 # sub-session anyway...
2013 # local $filename = $filename;
2014 # local *dbline = *dbline; # XXX Would this work?!
2016 # The above question wonders if localizing the alias
2017 # to the magic array works or not. Since it's commented
2018 # out, we'll just leave that to speculation for now.
2020 # If the "subname" isn't all digits, we'll assume it
2021 # is a subroutine name, and try to find it.
2022 if ( $subname =~ /\D/ ) { # subroutine name
2023 # Qualify it to the current package unless it's
2024 # already qualified.
2025 $subname = $package . "::" . $subname
2026 unless $subname =~ /::/;
2028 # find_sub will return "file:line_number" corresponding
2029 # to where the subroutine is defined; we call find_sub,
2030 # break up the return value, and assign it in one
2032 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2034 # Force the line number to be numeric.
2037 # If we got a line number, we found the sub.
2040 # Switch all the debugger's internals around so
2041 # we're actually working with that file.
2043 *dbline = $main::{ '_<' . $filename };
2045 # Mark that there's a breakpoint in this file.
2046 $had_breakpoints{$filename} |= 1;
2048 # Scan forward to the first executable line
2049 # after the 'sub whatever' line.
2052 while ($dbline[$_line_num] == 0 && $_line_num< $max)
2059 # We didn't find a sub by that name.
2061 print $OUT "Subroutine $subname not found.\n";
2064 } ## end if ($subname =~ /\D/)
2066 # At this point, either the subname was all digits (an
2067 # absolute line-break request) or we've scanned through
2068 # the code following the definition of the sub, looking
2069 # for an executable, which we may or may not have found.
2071 # If $i (which we set $subname from) is non-zero, we
2072 # got a request to break at some line somewhere. On
2073 # one hand, if there wasn't any real subroutine name
2074 # involved, this will be a request to break in the current
2075 # file at the specified line, so we have to check to make
2076 # sure that the line specified really is breakable.
2078 # On the other hand, if there was a subname supplied, the
2079 # preceding block has moved us to the proper file and
2080 # location within that file, and then scanned forward
2081 # looking for the next executable line. We have to make
2082 # sure that one was found.
2084 # On the gripping hand, we can't do anything unless the
2085 # current value of $i points to a valid breakable line.
2090 if ( $dbline[$i] == 0 ) {
2091 print $OUT "Line $i not breakable.\n";
2095 # Yes. Set up the one-time-break sigil.
2096 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2097 _enable_breakpoint_temp_enabled_status($filename, $i);
2100 # Turn off stack tracing from here up.
2101 for my $j (0 .. $stack_depth) {
2110 sub _DB__handle_forward_slash_command {
2113 # The pattern as a string.
2114 use vars qw($inpat);
2116 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2118 # Remove the final slash.
2119 $inpat =~ s:([^\\])/$:$1:;
2121 # If the pattern isn't null ...
2122 if ( $inpat ne "" ) {
2124 # Turn off warn and die processing for a bit.
2125 local $SIG{__DIE__};
2126 local $SIG{__WARN__};
2128 # Create the pattern.
2129 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2132 # Oops. Bad pattern. No biscuit.
2133 # Print the eval error and go back for more
2139 } ## end if ($inpat ne "")
2141 # Set up to stop on wrap-around.
2144 # Don't move off the current line.
2147 my $pat = $obj->pat;
2149 # Done in eval so nothing breaks if the pattern
2150 # does something weird.
2155 # Move ahead one line.
2158 # Wrap if we pass the last line.
2159 if ($start > $max) {
2163 # Stop if we have gotten back to this line again,
2164 last if ($start == $end);
2166 # A hit! (Note, though, that we are doing
2167 # case-insensitive matching. Maybe a qr//
2168 # expression would be better, so the user could
2169 # do case-sensitive matching if desired.
2170 if ($dbline[$start] =~ m/$pat/i) {
2171 if ($slave_editor) {
2172 # Handle proper escaping in the slave.
2173 print {$OUT} "\032\032$filename:$start:0\n";
2176 # Just print the line normally.
2177 print {$OUT} "$start:\t",$dbline[$start],"\n";
2179 # And quit since we found something.
2189 # If we wrapped, there never was a match.
2190 if ( $start == $end ) {
2191 print {$OUT} "/$pat/: not found\n";
2199 sub _DB__handle_question_mark_command {
2202 # ? - backward pattern search.
2203 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2205 # Get the pattern, remove trailing question mark.
2206 $inpat =~ s:([^\\])\?$:$1:;
2208 # If we've got one ...
2209 if ( $inpat ne "" ) {
2211 # Turn off die & warn handlers.
2212 local $SIG{__DIE__};
2213 local $SIG{__WARN__};
2214 eval '$inpat =~ m' . "\a$inpat\a";
2218 # Ouch. Not good. Print the error.
2223 } ## end if ($inpat ne "")
2225 # Where we are now is where to stop after wraparound.
2228 # Don't move away from this line.
2231 my $pat = $obj->pat;
2232 # Search inside the eval to prevent pattern badness
2240 # Wrap if we pass the first line.
2242 $start = $max if ($start <= 0);
2244 # Quit if we get back where we started,
2245 last if ($start == $end);
2248 if ($dbline[$start] =~ m/$pat/i) {
2249 if ($slave_editor) {
2250 # Yep, follow slave editor requirements.
2251 print $OUT "\032\032$filename:$start:0\n";
2254 # Yep, just print normally.
2255 print $OUT "$start:\t",$dbline[$start],"\n";
2264 # Say we failed if the loop never found anything,
2265 if ( $start == $end ) {
2266 print {$OUT} "?$pat?: not found\n";
2274 sub _DB__handle_restart_and_rerun_commands {
2277 my $cmd_cmd = $obj->cmd_verb;
2278 my $cmd_params = $obj->cmd_args;
2279 # R - restart execution.
2280 # rerun - controlled restart execution.
2281 if ($cmd_cmd eq 'rerun' or $cmd_params eq '') {
2283 # Change directory to the initial current working directory on
2284 # the script startup, so if the debugged program changed the
2285 # directory, then we will still be able to find the path to the
2286 # the program. (perl 5 RT #121509 ).
2287 chdir ($_initial_cwd);
2289 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
2291 # Close all non-system fds for a clean restart. A more
2292 # correct method would be to close all fds that were not
2293 # open when the process started, but this seems to be
2294 # hard. See "debugger 'R'estart and open database
2295 # connections" on p5p.
2297 my $max_fd = 1024; # default if POSIX can't be loaded
2298 if (eval { require POSIX }) {
2299 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
2302 if (defined $max_fd) {
2303 foreach ($^F+1 .. $max_fd-1) {
2304 next unless open FD_TO_CLOSE, "<&=$_";
2309 # And run Perl again. We use exec() to keep the
2310 # PID stable (and that way $ini_pids is still valid).
2311 exec(@args) or print {$OUT} "exec failed: $!\n";
2319 sub _DB__handle_run_command_in_pager_command {
2322 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
2323 if ( $pager =~ /^\|/ ) {
2325 # Default pager is into a pipe. Redirect I/O.
2326 open( SAVEOUT, ">&STDOUT" )
2327 || _db_warn("Can't save STDOUT");
2328 open( STDOUT, ">&OUT" )
2329 || _db_warn("Can't redirect STDOUT");
2330 } ## end if ($pager =~ /^\|/)
2333 # Not into a pipe. STDOUT is safe.
2334 open( SAVEOUT, ">&OUT" ) || _db_warn("Can't save DB::OUT");
2337 # Fix up environment to record we have less if so.
2340 unless ( $obj->piped(scalar ( open( OUT, $pager ) ) ) ) {
2342 # Couldn't open pipe to pager.
2343 _db_warn("Can't pipe output to '$pager'");
2344 if ( $pager =~ /^\|/ ) {
2346 # Redirect I/O back again.
2347 open( OUT, ">&STDOUT" ) # XXX: lost message
2348 || _db_warn("Can't restore DB::OUT");
2349 open( STDOUT, ">&SAVEOUT" )
2350 || _db_warn("Can't restore STDOUT");
2352 } ## end if ($pager =~ /^\|/)
2355 # Redirect I/O. STDOUT already safe.
2356 open( OUT, ">&STDOUT" ) # XXX: lost message
2357 || _db_warn("Can't restore DB::OUT");
2360 } ## end unless ($piped = open(OUT,...
2362 # Set up broken-pipe handler if necessary.
2363 $SIG{PIPE} = \&DB::catch
2365 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
2368 # Save current filehandle, and put it back.
2369 $obj->selected(scalar( select(OUT) ));
2370 # Don't put it back if pager was a pipe.
2371 if ($cmd !~ /\A\|\|/)
2373 select($obj->selected());
2377 # Trim off the pipe symbols and run the command now.
2378 $cmd =~ s#\A\|+\s*##;
2385 sub _DB__handle_m_command {
2388 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2393 # m expr - set up DB::eval to do the work
2394 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2395 $onetimeDump = 'methods'; # method output gets used there
2401 sub _DB__at_end_of_every_command {
2404 # At the end of every command:
2407 # Unhook the pipe mechanism now.
2408 if ( $pager =~ /^\|/ ) {
2410 # No error from the child.
2413 # we cannot warn here: the handle is missing --tchrist
2414 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
2416 # most of the $? crud was coping with broken cshisms
2417 # $? is explicitly set to 0, so this never runs.
2419 print SAVEOUT "Pager '$pager' failed: ";
2421 print SAVEOUT "shell returned -1\n";
2424 print SAVEOUT ( $? & 127 )
2425 ? " (SIG#" . ( $? & 127 ) . ")"
2426 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
2429 print SAVEOUT "status ", ( $? >> 8 ), "\n";
2433 # Reopen filehandle for our output (if we can) and
2434 # restore STDOUT (if we can).
2435 open( OUT, ">&STDOUT" ) || _db_warn("Can't restore DB::OUT");
2436 open( STDOUT, ">&SAVEOUT" )
2437 || _db_warn("Can't restore STDOUT");
2439 # Turn off pipe exception handler if necessary.
2440 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
2442 # Will stop ignoring SIGPIPE if done like nohup(1)
2443 # does SIGINT but Perl doesn't give us a choice.
2444 } ## end if ($pager =~ /^\|/)
2447 # Non-piped "pager". Just restore STDOUT.
2448 open( OUT, ">&SAVEOUT" ) || _db_warn("Can't restore DB::OUT");
2451 # Let Readline know about the new filehandles.
2452 reset_IN_OUT( \*IN, \*OUT );
2454 # Close filehandle pager was using, restore the normal one
2458 if ($obj->selected() ne "") {
2459 select($obj->selected);
2465 } ## end if ($piped)
2470 sub _DB__handle_watch_expressions
2474 if ( $DB::trace & 2 ) {
2475 for my $n (0 .. $#DB::to_watch) {
2476 $DB::evalarg = $DB::to_watch[$n];
2477 local $DB::onetimeDump; # Tell DB::eval() to not output results
2479 # Fix context DB::eval() wants to return an array, but
2480 # we need a scalar here.
2481 my ($val) = join( "', '", DB::eval(@_) );
2482 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
2485 if ( $val ne $DB::old_watch[$n] ) {
2487 # Yep! Show the difference, and fake an interrupt.
2489 print {$DB::OUT} <<EOP;
2490 Watchpoint $n:\t$DB::to_watch[$n] changed:
2491 old value:\t$DB::old_watch[$n]
2494 $DB::old_watch[$n] = $val;
2495 } ## end if ($val ne $old_watch...
2496 } ## end for my $n (0 ..
2497 } ## end if ($trace & 2)
2504 # 'v' is the value (i.e: method name or subroutine ref).
2505 # 's' is subroutine.
2512 '-' => { t => 'm', v => '_handle_dash_command', },
2513 '.' => { t => 's', v => \&_DB__handle_dot_command, },
2514 '=' => { t => 'm', v => '_handle_equal_sign_command', },
2515 'H' => { t => 'm', v => '_handle_H_command', },
2516 'S' => { t => 'm', v => '_handle_S_command', },
2517 'T' => { t => 'm', v => '_handle_T_command', },
2518 'W' => { t => 'm', v => '_handle_W_command', },
2519 'c' => { t => 's', v => \&_DB__handle_c_command, },
2520 'f' => { t => 's', v => \&_DB__handle_f_command, },
2521 'm' => { t => 's', v => \&_DB__handle_m_command, },
2522 'n' => { t => 'm', v => '_handle_n_command', },
2523 'p' => { t => 'm', v => '_handle_p_command', },
2524 'q' => { t => 'm', v => '_handle_q_command', },
2525 'r' => { t => 'm', v => '_handle_r_command', },
2526 's' => { t => 'm', v => '_handle_s_command', },
2527 'save' => { t => 'm', v => '_handle_save_command', },
2528 'source' => { t => 'm', v => '_handle_source_command', },
2529 't' => { t => 'm', v => '_handle_t_command', },
2530 'w' => { t => 'm', v => '_handle_w_command', },
2531 'x' => { t => 'm', v => '_handle_x_command', },
2532 'y' => { t => 's', v => \&_DB__handle_y_command, },
2533 (map { $_ => { t => 'm', v => '_handle_V_command_and_X_command', }, }
2535 (map { $_ => { t => 'm', v => '_handle_enable_disable_commands', }, }
2536 qw(enable disable)),
2538 { t => 's', v => \&_DB__handle_restart_and_rerun_commands, },
2540 (map { $_ => {t => 'm', v => '_handle_cmd_wrapper_commands' }, }
2541 qw(a A b B e E h i l L M o O v w W)),
2547 # lock the debugger and get the thread id for the prompt
2551 my ($prefix, $after, $infix);
2557 if ($ENV{PERL5DB_THREADED}) {
2558 $tid = eval { "[".threads->tid."]" };
2564 my $obj = DB::Obj->new(
2566 position => \$position,
2569 explicit_stop => \$explicit_stop,
2571 cmd_args => \$cmd_args,
2572 cmd_verb => \$cmd_verb,
2575 selected => \$selected,
2579 $obj->_DB_on_init__initialize_globals(@_);
2581 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
2582 # The code being debugged may have altered them.
2585 # Since DB::DB gets called after every line, we can use caller() to
2586 # figure out where we last were executing. Sneaky, eh? This works because
2587 # caller is returning all the extra information when called from the
2589 local ( $package, $filename, $line ) = caller;
2590 $filename_ini = $filename;
2592 # set up the context for DB::eval, so it can properly execute
2593 # code on behalf of the user. We add the package in so that the
2594 # code is eval'ed in the proper package (not in the debugger!).
2595 local $usercontext = _calc_usercontext($package);
2597 # Create an alias to the active file magical array to simplify
2599 local (*dbline) = $main::{ '_<' . $filename };
2601 # Last line in the program.
2604 # The &-call is here to ascertain the mutability of @_.
2605 &_DB__determine_if_we_should_break;
2607 # Preserve the current stop-or-not, and see if any of the W
2608 # (watch expressions) has changed.
2609 my $was_signal = $signal;
2611 # If we have any watch expressions ...
2612 _DB__handle_watch_expressions($obj);
2614 =head2 C<watchfunction()>
2616 C<watchfunction()> is a function that can be defined by the user; it is a
2617 function which will be run on each entry to C<DB::DB>; it gets the
2618 current package, filename, and line as its parameters.
2620 The watchfunction can do anything it likes; it is executing in the
2621 debugger's context, so it has access to all of the debugger's internal
2622 data structures and functions.
2624 C<watchfunction()> can control the debugger's actions. Any of the following
2625 will cause the debugger to return control to the user's program after
2626 C<watchfunction()> executes:
2632 Returning a false value from the C<watchfunction()> itself.
2636 Altering C<$single> to a false value.
2640 Altering C<$signal> to a false value.
2644 Turning off the C<4> bit in C<$trace> (this also disables the
2645 check for C<watchfunction()>. This can be done with
2653 # If there's a user-defined DB::watchfunction, call it with the
2654 # current package, filename, and line. The function executes in
2656 if ( $trace & 4 ) { # User-installed watch
2658 if watchfunction( $package, $filename, $line )
2661 and not( $trace & ~4 );
2662 } ## end if ($trace & 4)
2664 # Pick up any alteration to $signal in the watchfunction, and
2665 # turn off the signal now.
2666 $was_signal = $signal;
2669 =head2 GETTING READY TO EXECUTE COMMANDS
2671 The debugger decides to take control if single-step mode is on, the
2672 C<t> command was entered, or the user generated a signal. If the program
2673 has fallen off the end, we set things up so that entering further commands
2674 won't cause trouble, and we say that the program is over.
2678 # Make sure that we always print if asked for explicitly regardless
2679 # of $trace_to_depth .
2680 $explicit_stop = ($single || $was_signal);
2682 # Check to see if we should grab control ($single true,
2683 # trace set appropriately, or we got a signal).
2684 if ( $explicit_stop || ( $trace & 1 ) ) {
2685 $obj->_DB__grab_control(@_);
2686 } ## end if ($single || ($trace...
2690 If there's an action to be executed for the line we stopped at, execute it.
2691 If there are any preprompt actions, execute those as well.
2695 # If there's an action, do it now.
2698 # The &-call is here to ascertain the mutability of @_.
2702 # Are we nested another level (e.g., did we evaluate a function
2703 # that had a breakpoint in it at the debugger prompt)?
2704 if ( $single || $was_signal ) {
2706 # Yes, go down a level.
2707 local $level = $level + 1;
2709 # Do any pre-prompt actions.
2710 foreach $evalarg (@$pre) {
2711 # The &-call is here to ascertain the mutability of @_.
2715 # Complain about too much recursion if we passed the limit.
2717 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2720 # The line we're currently on. Set $incr to -1 to stay here
2721 # until we get a command that tells us to advance.
2723 $incr = -1; # for backward motion.
2725 # Tack preprompt debugger actions ahead of any actual input.
2726 @typeahead = ( @$pretype, @typeahead );
2728 =head2 WHERE ARE WE?
2730 XXX Relocate this section?
2732 The debugger normally shows the line corresponding to the current line of
2733 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2734 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2736 C<$incr> controls by how many lines the I<current> line should move forward
2737 after a command is executed. If set to -1, this indicates that the I<current>
2738 line shouldn't change.
2740 C<$start> is the I<current> line. It is used for things like knowing where to
2741 move forwards or backwards from when doing an C<L> or C<-> command.
2743 C<$max> tells the debugger where the last line of the current file is. It's
2744 used to terminate loops most often.
2746 =head2 THE COMMAND LOOP
2748 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2755 The outer part of the loop, starting at the C<CMD> label. This loop
2756 reads a command and then executes it.
2760 The inner part of the loop, starting at the C<PIPE> label. This part
2761 is wholly contained inside the C<CMD> block and only executes a command.
2762 Used to handle commands running inside a pager.
2766 So why have two labels to restart the loop? Because sometimes, it's easier to
2767 have a command I<generate> another command and then re-execute the loop to do
2768 the new command. This is faster, but perhaps a bit more convoluted.
2772 # The big command dispatch loop. It keeps running until the
2773 # user yields up control again.
2775 # If we have a terminal for input, and we get something back
2776 # from readline(), keep on processing.
2779 while (_DB__read_next_cmd($tid))
2783 # ... try to execute the input as debugger commands.
2785 # Don't stop running.
2788 # No signal is active.
2791 # Handle continued commands (ending with \):
2792 if ($cmd =~ s/\\\z/\n/) {
2793 $cmd .= DB::readline(" cont: ");
2797 =head4 The null command
2799 A newline entered by itself means I<re-execute the last command>. We grab the
2800 command out of C<$laststep> (where it was recorded previously), and copy it
2801 back into C<$cmd> to be executed below. If there wasn't any previous command,
2802 we'll do nothing below (no command will match). If there was, we also save it
2803 in the command history and fall through to allow the command parsing to pick
2808 # Empty input means repeat the last command.
2812 chomp($cmd); # get rid of the annoying extra newline
2813 if (length($cmd) >= 2) {
2814 push( @hist, $cmd );
2816 push( @truehist, $cmd );
2820 # This is a restart point for commands that didn't arrive
2821 # via direct user input. It allows us to 'redo PIPE' to
2822 # re-execute command processing without reading a new command.
2824 _DB__trim_command_and_return_first_component($obj);
2826 =head3 COMMAND ALIASES
2828 The debugger can create aliases for commands (these are stored in the
2829 C<%alias> hash). Before a command is executed, the command loop looks it up
2830 in the alias hash and substitutes the contents of the alias for the command,
2831 completely replacing it.
2835 # See if there's an alias for the command, and set it up if so.
2836 if ( $alias{$cmd_verb} ) {
2838 # Squelch signal handling; we want to keep control here
2839 # if something goes loco during the alias eval.
2840 local $SIG{__DIE__};
2841 local $SIG{__WARN__};
2843 # This is a command, so we eval it in the DEBUGGER's
2844 # scope! Otherwise, we can't see the special debugger
2845 # variables, or get to the debugger's subs. (Well, we
2846 # _could_, but why make it even more complicated?)
2847 eval "\$cmd =~ $alias{$cmd_verb}";
2850 print $OUT "Couldn't evaluate '$cmd_verb' alias: $@";
2853 _DB__trim_command_and_return_first_component($obj);
2854 } ## end if ($alias{$cmd_verb})
2856 =head3 MAIN-LINE COMMANDS
2858 All of these commands work up to and after the program being debugged has
2863 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2864 try to execute further, cleaning any restart-related stuff out of the
2865 environment, and executing with the last value of C<$?>.
2869 # All of these commands were remapped in perl 5.8.0;
2870 # we send them off to the secondary dispatcher (see below).
2871 $obj->_handle_special_char_cmd_wrapper_commands;
2872 _DB__trim_command_and_return_first_component($obj);
2874 if (my $cmd_rec = $cmd_lookup{$cmd_verb}) {
2875 my $type = $cmd_rec->{t};
2876 my $val = $cmd_rec->{v};
2880 elsif ($type eq 's') {
2885 =head4 C<t> - trace [n]
2887 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2888 If level is specified, set C<$trace_to_depth>.
2890 =head4 C<S> - list subroutines matching/not matching a pattern
2892 Walks through C<%sub>, checking to see whether or not to print the name.
2894 =head4 C<X> - list variables in current package
2896 Since the C<V> command actually processes this, just change this to the
2897 appropriate C<V> command and fall through.
2899 =head4 C<V> - list variables
2901 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2903 =head4 C<x> - evaluate and print an expression
2905 Hands the expression off to C<DB::eval>, setting it up to print the value
2906 via C<dumpvar.pl> instead of just printing it directly.
2908 =head4 C<m> - print methods
2910 Just uses C<DB::methods> to determine what methods are available.
2912 =head4 C<f> - switch files
2914 Switch to a different filename.
2916 =head4 C<.> - return to last-executed line.
2918 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2919 and then we look up the line in the magical C<%dbline> hash.
2921 =head4 C<-> - back one window
2923 We change C<$start> to be one window back; if we go back past the first line,
2924 we set it to be the first line. We ser C<$incr> to put us back at the
2925 currently-executing line, and then put a C<l $start +> (list one window from
2926 C<$start>) in C<$cmd> to be executed later.
2928 =head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
2930 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2931 problems, most notably that the default case of several commands destroying
2932 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2933 retain the old commands for those who were used to using them or who preferred
2934 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2935 deal with them instead of processing them in-line.
2937 =head4 C<y> - List lexicals in higher scope
2939 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2940 above the current one and then displays then using C<dumpvar.pl>.
2942 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2944 All of the commands below this point don't work after the program being
2945 debugged has ended. All of them check to see if the program has ended; this
2946 allows the commands to be relocated without worrying about a 'line of
2947 demarcation' above which commands can be entered anytime, and below which
2950 =head4 C<n> - single step, but don't trace down into subs
2952 Done by setting C<$single> to 2, which forces subs to execute straight through
2953 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2954 so a null command knows what to re-execute.
2956 =head4 C<s> - single-step, entering subs
2958 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2959 subs. Also saves C<s> as C<$lastcmd>.
2961 =head4 C<c> - run continuously, setting an optional breakpoint
2963 Most of the code for this command is taken up with locating the optional
2964 breakpoint, which is either a subroutine name or a line number. We set
2965 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2966 in this and all call levels above this one.
2968 =head4 C<r> - return from a subroutine
2970 For C<r> to work properly, the debugger has to stop execution again
2971 immediately after the return is executed. This is done by forcing
2972 single-stepping to be on in the call level above the current one. If
2973 we are printing return values when a C<r> is executed, set C<$doret>
2974 appropriately, and force us out of the command loop.
2976 =head4 C<T> - stack trace
2978 Just calls C<DB::print_trace>.
2980 =head4 C<w> - List window around current line.
2982 Just calls C<DB::cmd_w>.
2984 =head4 C<W> - watch-expression processing.
2986 Just calls C<DB::cmd_W>.
2988 =head4 C</> - search forward for a string in the source
2990 We take the argument and treat it as a pattern. If it turns out to be a
2991 bad one, we return the error we got from trying to C<eval> it and exit.
2992 If not, we create some code to do the search and C<eval> it so it can't
2997 _DB__handle_forward_slash_command($obj);
2999 =head4 C<?> - search backward for a string in the source
3001 Same as for C</>, except the loop runs backwards.
3005 _DB__handle_question_mark_command($obj);
3007 =head4 C<$rc> - Recall command
3009 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
3010 that the terminal supports history). It finds the command required, puts it
3011 into C<$cmd>, and redoes the loop to execute it.
3015 # $rc - recall command.
3016 $obj->_handle_rc_recall_command;
3018 =head4 C<$sh$sh> - C<system()> command
3020 Calls the C<_db_system()> to handle the command. This keeps the C<STDIN> and
3021 C<STDOUT> from getting messed up.
3025 $obj->_handle_sh_command;
3027 =head4 C<$rc I<pattern> $rc> - Search command history
3029 Another command to manipulate C<@hist>: this one searches it with a pattern.
3030 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
3034 $obj->_handle_rc_search_history_command;
3036 =head4 C<$sh> - Invoke a shell
3038 Uses C<_db_system()> to invoke a shell.
3042 =head4 C<$sh I<command>> - Force execution of a command in a shell
3044 Like the above, but the command is passed to the shell. Again, we use
3045 C<_db_system()> to avoid problems with C<STDIN> and C<STDOUT>.
3047 =head4 C<H> - display commands in history
3049 Prints the contents of C<@hist> (if any).
3051 =head4 C<man, doc, perldoc> - look up documentation
3053 Just calls C<runman()> to print the appropriate document.
3057 $obj->_handle_doc_command;
3061 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3062 the bottom of the loop.
3064 =head4 C<=> - define command alias
3066 Manipulates C<%alias> to add or list command aliases.
3068 =head4 C<source> - read commands from a file.
3070 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3073 =head4 C<enable> C<disable> - enable or disable breakpoints
3075 This enables or disables breakpoints.
3077 =head4 C<save> - send current history to a file
3079 Takes the complete history, (not the shrunken version you see with C<H>),
3080 and saves it to the given filename, so it can be replayed using C<source>.
3082 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3084 =head4 C<R> - restart
3086 Restart the debugger session.
3088 =head4 C<rerun> - rerun the current session
3090 Return to any given position in the B<true>-history list
3092 =head4 C<|, ||> - pipe output through the pager.
3094 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3095 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3096 pipe to the pager (restoring the output filehandles if this fails). If this
3097 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3098 set C<$signal>, sending us back into the debugger.
3100 We then trim off the pipe symbols and C<redo> the command loop at the
3101 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3106 # || - run command in the pager, with output to DB::OUT.
3107 _DB__handle_run_command_in_pager_command($obj);
3109 =head3 END OF COMMAND PARSING
3111 Anything left in C<$cmd> at this point is a Perl expression that we want to
3112 evaluate. We'll always evaluate in the user's context, and fully qualify
3113 any variables we might want to address in the C<DB> package.
3119 # trace an expression
3120 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3122 # Make sure the flag that says "the debugger's running" is
3123 # still on, to make sure we get control again.
3124 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3126 # Run *our* eval that executes in the caller's context.
3127 # The &-call is here to ascertain the mutability of @_.
3130 # Turn off the one-time-dump stuff now.
3132 $onetimeDump = undef;
3133 $onetimedumpDepth = undef;
3135 elsif ( $term_pid == $$ ) {
3136 eval { # May run under miniperl, when not available...
3141 # XXX If this is the master pid, print a newline.
3144 } ## end while (($term || &setterm...
3146 =head3 POST-COMMAND PROCESSING
3148 After each command, we check to see if the command output was piped anywhere.
3149 If so, we go through the necessary code to unhook the pipe and go back to
3150 our standard filehandles for input and output.
3155 _DB__at_end_of_every_command($obj);
3158 =head3 COMMAND LOOP TERMINATION
3160 When commands have finished executing, we come here. If the user closed the
3161 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3162 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3163 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3164 The interpreter will then execute the next line and then return control to us
3169 # No more commands? Quit.
3170 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
3172 # Evaluate post-prompt commands.
3173 foreach $evalarg (@$post) {
3174 # The &-call is here to ascertain the mutability of @_.
3177 } # if ($single || $signal)
3179 # Put the user's globals back where you found them.
3180 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3184 # Because DB::Obj is used above,
3186 # my $obj = DB::Obj->new(
3188 # The following package declaration must come before that,
3189 # or else runtime errors will occur with
3191 # PERLDB_OPTS="autotrace nonstop"
3201 my $self = bless {}, $class;
3209 my ($self, $args) = @_;
3211 %{$self} = (%$self, %$args);
3218 foreach my $slot_name (qw(
3219 after explicit_stop infix pat piped position prefix selected cmd_verb
3222 my $slot = $slot_name;
3227 ${ $self->{$slot} } = shift;
3230 return ${ $self->{$slot} };
3233 *{"append_to_$slot"} = sub {
3237 return $self->$slot($self->$slot . $s);
3242 sub _DB_on_init__initialize_globals
3246 # Check for whether we should be running continuously or not.
3247 # _After_ the perl program is compiled, $single is set to 1:
3248 if ( $single and not $second_time++ ) {
3250 # Options say run non-stop. Run until we get an interrupt.
3251 if ($runnonstop) { # Disable until signal
3252 # If there's any call stack in place, turn off single
3253 # stepping into subs throughout the stack.
3254 for my $i (0 .. $stack_depth) {
3258 # And we are now no longer in single-step mode.
3261 # If we simply returned at this point, we wouldn't get
3262 # the trace info. Fall on through.
3264 } ## end if ($runnonstop)
3266 elsif ($ImmediateStop) {
3268 # We are supposed to stop here; XXX probably a break.
3269 $ImmediateStop = 0; # We've processed it; turn it off
3270 $signal = 1; # Simulate an interrupt to force
3271 # us into the command loop
3273 } ## end if ($single and not $second_time...
3275 # If we're in single-step mode, or an interrupt (real or fake)
3276 # has occurred, turn off non-stop mode.
3277 $runnonstop = 0 if $single or $signal;
3282 sub _my_print_lineinfo
3284 my ($self, $i, $incr_pos) = @_;
3287 # Print it indented if tracing is on.
3288 DB::print_lineinfo( ' ' x $stack_depth,
3289 "$i:\t$DB::dbline[$i]" . $self->after );
3292 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3297 return $DB::dbline[$line];
3301 my ($self, $letter) = @_;
3303 return ($DB::cmd eq $letter);
3306 sub _DB__grab_control
3310 # Yes, grab control.
3311 if ($slave_editor) {
3313 # Tell the editor to update its position.
3314 $self->position("\032\032${DB::filename}:$line:0\n");
3315 DB::print_lineinfo($self->position());
3320 Special check: if we're in package C<DB::fake>, we've gone through the
3321 C<END> block at least once. We set up everything so that we can continue
3322 to enter commands and have a valid context to be in.
3326 elsif ( $DB::package eq 'DB::fake' ) {
3328 # Fallen off the end already.
3333 DB::print_help(<<EOP);
3334 Debugged program terminated. Use B<q> to quit or B<R> to restart,
3335 use B<o> I<inhibit_exit> to avoid stopping after program termination,
3336 B<h q>, B<h R> or B<h o> to get additional info.
3339 # Set the DB::eval context appropriately.
3340 # At program termination disable any user actions.
3341 $DB::action = undef;
3343 $DB::package = 'main';
3344 $DB::usercontext = DB::_calc_usercontext($DB::package);
3345 } ## end elsif ($package eq 'DB::fake')
3349 If the program hasn't finished executing, we scan forward to the
3350 next executable line, print that out, build the prompt from the file and line
3351 number information, and print that.
3358 # Still somewhere in the midst of execution. Set up the
3360 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3361 # Perl 5 ones (sorry, we don't print Klingon
3364 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
3365 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
3366 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
3368 # Break up the prompt if it's really long.
3369 if ( length($self->prefix()) > 30 ) {
3370 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
3372 $self->infix(":\t");
3375 $self->infix("):\t");
3377 $self->prefix . $line. $self->infix
3378 . $self->_curr_line . $self->after
3382 # Print current line info, indenting if necessary.
3383 $self->_my_print_lineinfo($line, $self->position);
3386 my $line_i = sub { return $DB::dbline[$i]; };
3388 # Scan forward, stopping at either the end or the next
3390 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
3393 # Drop out on null statements, block closers, and comments.
3394 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
3396 # Drop out if the user interrupted us.
3399 # Append a newline if the line doesn't have one. Can happen
3400 # in eval'ed text, for instance.
3401 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
3403 # Next executable line.
3404 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
3406 $self->append_to_position($incr_pos);
3407 $self->_my_print_lineinfo($i, $incr_pos);
3408 } ## end for ($i = $line + 1 ; $i...
3409 } ## end else [ if ($slave_editor)
3414 sub _handle_t_command {
3417 my $levels = $self->cmd_args();
3419 if ((!length($levels)) or ($levels !~ /\D/)) {
3422 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
3423 print {$OUT} "Trace = "
3425 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3434 sub _handle_S_command {
3437 if (my ($print_all_subs, $should_reverse, $Spatt)
3438 = $self->cmd_args =~ /\A((!)?(.+))?\z/) {
3439 # $Spatt is the pattern (if any) to use.
3441 my $Srev = defined $should_reverse;
3442 # No args - print all subs.
3443 my $Snocheck = !defined $print_all_subs;
3445 # Need to make these sane here.
3449 # Search through the debugger's magical hash of subs.
3450 # If $nocheck is true, just print the sub name.
3451 # Otherwise, check it against the pattern. We then use
3452 # the XOR trick to reverse the condition as required.
3453 foreach $subname ( sort( keys %sub ) ) {
3454 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
3455 print $OUT $subname, "\n";
3464 sub _handle_V_command_and_X_command {
3467 $DB::cmd =~ s/^X\b/V $DB::package/;
3469 # Bare V commands get the currently-being-debugged package
3471 if ($self->_is_full('V')) {
3472 $DB::cmd = "V $DB::package";
3475 # V - show variables in package.
3476 if (my ($new_packname, $new_vars_str) =
3477 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
3479 # Save the currently selected filehandle and
3480 # force output to debugger's filehandle (dumpvar
3481 # just does "print" for output).
3482 my $savout = select($OUT);
3484 # Grab package name and variables to dump.
3485 $packname = $new_packname;
3486 my @vars = split( ' ', $new_vars_str );
3488 # If main::dumpvar isn't here, get it.
3489 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
3490 if ( defined &main::dumpvar ) {
3492 # We got it. Turn off subroutine entry/exit messages
3493 # for the moment, along with return values.
3497 # must detect sigpipe failures - not catching
3498 # then will cause the debugger to die.
3502 defined $option{dumpDepth}
3503 ? $option{dumpDepth}
3504 : -1, # assume -1 unless specified
3509 # The die doesn't need to include the $@, because
3510 # it will automatically get propagated for us.
3512 die unless $@ =~ /dumpvar print failed/;
3514 } ## end if (defined &main::dumpvar)
3517 # Couldn't load dumpvar.
3518 print $OUT "dumpvar.pl not available.\n";
3521 # Restore the output filehandle, and go round again.
3529 sub _handle_dash_command {
3532 if ($self->_is_full('-')) {
3534 # back up by a window; go to 1 if back too far.
3535 $start -= $incr + $window + 1;
3536 $start = 1 if $start <= 0;
3537 $incr = $window - 1;
3539 # Generate and execute a "l +" command (handled below).
3540 $DB::cmd = 'l ' . ($start) . '+';
3546 sub _n_or_s_commands_generic {
3547 my ($self, $new_val) = @_;
3549 next CMD if DB::_DB__is_finished();
3551 # Single step, but don't enter subs.
3554 # Save for empty command (repeat last).
3555 $laststep = $DB::cmd;
3560 my ($self, $letter, $new_val) = @_;
3562 if ($self->_is_full($letter)) {
3563 $self->_n_or_s_commands_generic($new_val);
3566 $self->_n_or_s_and_arg_commands_generic($letter, $new_val);
3572 sub _handle_n_command {
3575 return $self->_n_or_s('n', 2);
3578 sub _handle_s_command {
3581 return $self->_n_or_s('s', 1);
3584 sub _handle_r_command {
3587 # r - return from the current subroutine.
3588 if ($self->_is_full('r')) {
3590 # Can't do anything if the program's over.
3591 next CMD if DB::_DB__is_finished();
3593 # Turn on stack trace.
3594 $stack[$stack_depth] |= 1;
3596 # Print return value unless the stack is empty.
3597 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
3604 sub _handle_T_command {
3607 if ($self->_is_full('T')) {
3608 DB::print_trace( $OUT, 1 ); # skip DB
3615 sub _handle_w_command {
3618 DB::cmd_w( 'w', $self->cmd_args() );
3624 sub _handle_W_command {
3627 if (my $arg = $self->cmd_args) {
3628 DB::cmd_W( 'W', $arg );
3635 sub _handle_rc_recall_command {
3638 # $rc - recall command.
3639 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
3641 # No arguments, take one thing off history.
3642 pop(@hist) if length($DB::cmd) > 1;
3644 # Relative (- found)?
3645 # Y - index back from most recent (by 1 if bare minus)
3646 # N - go to that particular command slot or the last
3647 # thing if nothing following.
3650 scalar($minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist ))
3653 # Pick out the command desired.
3654 $DB::cmd = $hist[$self->cmd_verb];
3656 # Print the command to be executed and restart the loop
3657 # with that command in the buffer.
3658 print {$OUT} $DB::cmd, "\n";
3665 sub _handle_rc_search_history_command {
3668 # $rc pattern $rc - find a command in the history.
3669 if (my ($arg) = $DB::cmd =~ /\A$rc([^$rc].*)\z/) {
3671 # Create the pattern to use.
3675 # Toss off last entry if length is >1 (and it always is).
3676 pop(@hist) if length($DB::cmd) > 1;
3680 # Look backward through the history.
3682 for ( $i = $#hist ; $i ; --$i ) {
3683 # Stop if we find it.
3684 last SEARCH_HIST if $hist[$i] =~ /$pat/;
3690 print $OUT "No such command!\n\n";
3694 # Found it. Put it in the buffer, print it, and process it.
3695 $DB::cmd = $hist[$i];
3696 print $OUT $DB::cmd, "\n";
3703 sub _handle_H_command {
3706 if ($self->cmd_args =~ m#\A\*#) {
3707 @hist = @truehist = ();
3708 print $OUT "History cleansed\n";
3712 if (my ($num) = $self->cmd_args =~ /\A(?:-(\d+))?/) {
3714 # Anything other than negative numbers is ignored by
3715 # the (incorrect) pattern, so this test does nothing.
3716 $end = $num ? ( $#hist - $num ) : 0;
3718 # Set to the minimum if less than zero.
3719 $hist = 0 if $hist < 0;
3721 # Start at the end of the array.
3722 # Stay in while we're still above the ending value.
3723 # Tick back by one each time around the loop.
3726 for ( $i = $#hist ; $i > $end ; $i-- ) {
3728 # Print the command unless it has no arguments.
3729 print $OUT "$i: ", $hist[$i], "\n"
3730 unless $hist[$i] =~ /^.?$/;
3739 sub _handle_doc_command {
3742 # man, perldoc, doc - show manual pages.
3744 = $DB::cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
3745 DB::runman($man_page);
3752 sub _handle_p_command {
3755 my $print_cmd = 'print {$DB::OUT} ';
3756 # p - print (no args): print $_.
3757 if ($self->_is_full('p')) {
3758 $DB::cmd = $print_cmd . '$_';
3761 # p - print the given expression.
3762 $DB::cmd =~ s/\Ap\b/$print_cmd /;
3768 sub _handle_equal_sign_command {
3771 if ($DB::cmd =~ s/\A=\s*//) {
3773 if ( length $DB::cmd == 0 ) {
3775 # No args, get current aliases.
3776 @keys = sort keys %alias;
3778 elsif ( my ( $k, $v ) = ( $DB::cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3780 # Creating a new alias. $k is alias name, $v is
3783 # can't use $_ or kill //g state
3784 for my $x ( $k, $v ) {
3786 # Escape "alarm" characters.
3790 # Substitute key for value, using alarm chars
3791 # as separators (which is why we escaped them in
3793 $alias{$k} = "s\a$k\a$v\a";
3795 # Turn off standard warn and die behavior.
3796 local $SIG{__DIE__};
3797 local $SIG{__WARN__};
3800 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3802 # Nope. Bad alias. Say so and get out.
3803 print $OUT "Can't alias $k to $v: $@\n";
3808 # We'll only list the new one.
3810 } ## end elsif (my ($k, $v) = ($DB::cmd...
3812 # The argument is the alias to list.
3820 # Messy metaquoting: Trim the substitution code off.
3821 # We use control-G as the delimiter because it's not
3822 # likely to appear in the alias.
3823 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3826 print $OUT "$k\t= $1\n";
3828 elsif ( defined $alias{$k} ) {
3830 # Couldn't trim it off; just print the alias code.
3831 print $OUT "$k\t$alias{$k}\n";
3836 print "No alias for $k\n";
3838 } ## end for my $k (@keys)
3845 sub _handle_source_command {
3848 # source - read commands from a file (or pipe!) and execute.
3849 if (my $sourced_fn = $self->cmd_args) {
3850 if ( open my $fh, $sourced_fn ) {
3852 # Opened OK; stick it in the list of file handles.
3858 DB::_db_warn("Can't execute '$sourced_fn': $!\n");
3866 sub _handle_enable_disable_commands {
3869 my $which_cmd = $self->cmd_verb;
3870 my $position = $self->cmd_args;
3872 if ($position !~ /\s/) {
3873 my ($fn, $line_num);
3874 if ($position =~ m{\A\d+\z})
3876 $fn = $DB::filename;
3877 $line_num = $position;
3879 elsif (my ($new_fn, $new_line_num)
3880 = $position =~ m{\A(.*):(\d+)\z}) {
3881 ($fn, $line_num) = ($new_fn, $new_line_num);
3885 DB::_db_warn("Wrong spec for enable/disable argument.\n");
3889 if (DB::_has_breakpoint_data_ref($fn, $line_num)) {
3890 DB::_set_breakpoint_enabled_status($fn, $line_num,
3891 ($which_cmd eq 'enable' ? 1 : '')
3895 DB::_db_warn("No breakpoint set at ${fn}:${line_num}\n");
3905 sub _handle_save_command {
3908 if (my $new_fn = $self->cmd_args) {
3909 my $filename = $new_fn || '.perl5dbrc'; # default?
3910 if ( open my $fh, '>', $filename ) {
3912 # chomp to remove extraneous newlines from source'd files
3913 chomp( my @truelist =
3914 map { m/\A\s*(save|source)/ ? "#$_" : $_ }
3916 print {$fh} join( "\n", @truelist );
3917 print "commands saved in $filename\n";
3920 DB::_db_warn("Can't save debugger commands in '$new_fn': $!\n");
3928 sub _n_or_s_and_arg_commands_generic {
3929 my ($self, $letter, $new_val) = @_;
3931 # s - single-step. Remember the last command was 's'.
3932 if ($DB::cmd =~ s#\A\Q$letter\E\s#\$DB::single = $new_val;\n#) {
3933 $laststep = $letter;
3939 sub _handle_sh_command {
3942 # $sh$sh - run a shell command (if it's all ASCII).
3943 # Can't run shell commands with Unicode in the debugger, hmm.
3944 my $my_cmd = $DB::cmd;
3945 if ($my_cmd =~ m#\A$sh#gms) {
3947 if ($my_cmd =~ m#\G\z#cgms) {
3948 # Run the user's shell. If none defined, run Bourne.
3949 # We resume execution when the shell terminates.
3950 DB::_db_system( $ENV{SHELL} || "/bin/sh" );
3953 elsif ($my_cmd =~ m#\G$sh\s*(.*)#cgms) {
3958 elsif ($my_cmd =~ m#\G\s*(.*)#cgms) {
3959 DB::_db_system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3965 sub _handle_x_command {
3968 if ($DB::cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
3969 $onetimeDump = 'dump'; # main::dumpvar shows the output
3971 # handle special "x 3 blah" syntax XXX propagate
3972 # doc back to special variables.
3973 if ( $DB::cmd =~ s#\A\s*(\d+)(?=\s)# #) {
3974 $onetimedumpDepth = $1;
3981 sub _handle_q_command {
3984 if ($self->_is_full('q')) {
3993 sub _handle_cmd_wrapper_commands {
3996 DB::cmd_wrapper( $self->cmd_verb, $self->cmd_args, $line );
4000 sub _handle_special_char_cmd_wrapper_commands {
4003 # All of these commands were remapped in perl 5.8.0;
4004 # we send them off to the secondary dispatcher (see below).
4005 if (my ($cmd_letter, $my_arg) = $DB::cmd =~ /\A([<>\{]{1,2})\s*(.*)/so) {
4006 DB::cmd_wrapper( $cmd_letter, $my_arg, $line );
4017 # The following code may be executed now:
4022 C<sub> is called whenever a subroutine call happens in the program being
4023 debugged. The variable C<$DB::sub> contains the name of the subroutine
4026 The core function of this subroutine is to actually call the sub in the proper
4027 context, capturing its output. This of course causes C<DB::DB> to get called
4028 again, repeating until the subroutine ends and returns control to C<DB::sub>
4029 again. Once control returns, C<DB::sub> figures out whether or not to dump the
4030 return value, and returns its captured copy of the return value as its own
4031 return value. The value then feeds back into the program being debugged as if
4032 C<DB::sub> hadn't been there at all.
4034 C<sub> does all the work of printing the subroutine entry and exit messages
4035 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
4036 and also prints the return value if needed (for the C<r> command and if
4037 the 16 bit is set in C<$frame>).
4039 It also tracks the subroutine call depth by saving the current setting of
4040 C<$single> in the C<@stack> package global; if this exceeds the value in
4041 C<$deep>, C<sub> automatically turns on printing of the current depth by
4042 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
4043 of stop/don't stop on entry to subs set as it currently is set.
4045 =head3 C<caller()> support
4047 If C<caller()> is called from the package C<DB>, it provides some
4048 additional data, in the following order:
4054 The package name the sub was in
4056 =item * C<$filename>
4058 The filename it was defined in
4062 The line number it was defined on
4064 =item * C<$subroutine>
4066 The subroutine name; C<(eval)> if an C<eval>().
4070 1 if it has arguments, 0 if not
4072 =item * C<$wantarray>
4074 1 if array context, 0 if scalar context
4076 =item * C<$evaltext>
4078 The C<eval>() text, if any (undefined for C<eval BLOCK>)
4080 =item * C<$is_require>
4082 frame was created by a C<use> or C<require> statement
4086 pragma information; subject to change between versions
4090 pragma information; subject to change between versions
4092 =item * C<@DB::args>
4094 arguments with which the subroutine was invoked
4102 # We need to fully qualify the name ("DB::sub") to make "use strict;"
4103 # happy. -- Shlomi Fish
4105 sub _indent_print_line_info {
4106 my ($offset, $str) = @_;
4108 print_lineinfo( ' ' x ($stack_depth - $offset), $str);
4113 sub _print_frame_message {
4117 if ($frame & 4) { # Extended frame entry message
4118 _indent_print_line_info(-1, "in ");
4120 # Why -1? But it works! :-(
4121 # Because print_trace will call add 1 to it and then call
4122 # dump_trace; this results in our skipping -1+1 = 0 stack frames
4125 # Now it's 0 because we extracted a function.
4126 print_trace( $LINEINFO, 0, 1, 1, "$sub$al" );
4129 _indent_print_line_info(-1, "entering $sub$al\n" );
4137 # lock ourselves under threads
4140 # Whether or not the autoloader was running, a scalar to put the
4141 # sub's return value in (if needed), and an array to put the sub's
4142 # return value in (if needed).
4143 my ( $al, $ret, @ret ) = "";
4144 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) {
4145 print "creating new thread\n";
4148 # If the last ten characters are '::AUTOLOAD', note we've traced
4149 # into AUTOLOAD for $sub.
4150 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
4152 $al = " for $$sub" if defined $$sub;
4155 # We stack the stack pointer and then increment it to protect us
4156 # from a situation that might unwind a whole bunch of call frames
4157 # at once. Localizing the stack pointer means that it will automatically
4158 # unwind the same amount when multiple stack frames are unwound.
4159 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
4162 $#stack = $stack_depth;
4164 # Save current single-step setting.
4165 $stack[-1] = $single;
4167 # Turn off all flags except single-stepping.
4170 # If we've gotten really deeply recursed, turn on the flag that will
4171 # make us stop with the 'deep recursion' message.
4172 $single |= 4 if $stack_depth == $deep;
4174 # If frame messages are on ...
4176 _print_frame_message($al);
4177 # standard frame entry message
4179 my $print_exit_msg = sub {
4180 # Check for exit trace messages...
4183 if ($frame & 4) # Extended exit message
4185 _indent_print_line_info(0, "out ");
4186 print_trace( $LINEINFO, 0, 1, 1, "$sub$al" );
4190 _indent_print_line_info(0, "exited $sub$al\n" );
4196 # Determine the sub's return type, and capture appropriately.
4199 # Called in array context. call sub and capture output.
4200 # DB::DB will recursively get control again if appropriate; we'll come
4201 # back here when the sub is finished.
4207 # Pop the single-step value back off the stack.
4208 $single |= $stack[ $stack_depth-- ];
4210 $print_exit_msg->();
4212 # Print the return info if we need to.
4213 if ( $doret eq $stack_depth or $frame & 16 ) {
4215 # Turn off output record separator.
4217 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4219 # Indent if we're printing because of $frame tracing.
4222 print {$fh} ' ' x $stack_depth;
4225 # Print the return value.
4226 print {$fh} "list context return from $sub:\n";
4227 dumpit( $fh, \@ret );
4229 # And don't print it again.
4231 } ## end if ($doret eq $stack_depth...
4232 # And we have to return the return value now.
4234 } ## end if (wantarray)
4238 if ( defined wantarray ) {
4240 # Save the value if it's wanted at all.
4245 # Void return, explicitly.
4250 # Pop the single-step value off the stack.
4251 $single |= $stack[ $stack_depth-- ];
4253 # If we're doing exit messages...
4254 $print_exit_msg->();
4256 # If we are supposed to show the return value... same as before.
4257 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
4259 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4260 print $fh ( ' ' x $stack_depth ) if $frame & 16;
4263 ? "scalar context return from $sub: "
4264 : "void context return from $sub\n"
4266 dumpit( $fh, $ret ) if defined wantarray;
4268 } ## end if ($doret eq $stack_depth...
4270 # Return the appropriate scalar value.
4272 } ## end else [ if (wantarray)
4279 # lock ourselves under threads
4282 # Whether or not the autoloader was running, a scalar to put the
4283 # sub's return value in (if needed), and an array to put the sub's
4284 # return value in (if needed).
4285 my ( $al, $ret, @ret ) = "";
4286 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
4287 print "creating new thread\n";
4290 # If the last ten characters are C'::AUTOLOAD', note we've traced
4291 # into AUTOLOAD for $sub.
4292 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
4296 # We stack the stack pointer and then increment it to protect us
4297 # from a situation that might unwind a whole bunch of call frames
4298 # at once. Localizing the stack pointer means that it will automatically
4299 # unwind the same amount when multiple stack frames are unwound.
4300 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
4303 $#stack = $stack_depth;
4305 # Save current single-step setting.
4306 $stack[-1] = $single;
4308 # Turn off all flags except single-stepping.
4309 # Use local so the single-step value is popped back off the
4311 local $single = $single & 1;
4313 # If we've gotten really deeply recursed, turn on the flag that will
4314 # make us stop with the 'deep recursion' message.
4315 $single |= 4 if $stack_depth == $deep;
4317 # If frame messages are on ...
4318 _print_frame_message($al);
4320 # call the original lvalue sub.
4324 # Abstracting common code from multiple places elsewhere:
4325 sub depth_print_lineinfo {
4326 my $always_print = shift;
4328 print_lineinfo( @_ ) if ($always_print or $stack_depth < $trace_to_depth);
4331 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
4333 In Perl 5.8.0, there was a major realignment of the commands and what they did,
4334 Most of the changes were to systematize the command structure and to eliminate
4335 commands that threw away user input without checking.
4337 The following sections describe the code added to make it easy to support
4338 multiple command sets with conflicting command names. This section is a start
4339 at unifying all command processing to make it simpler to develop commands.
4341 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
4342 number, and C<$dbline> (the current line) as arguments.
4344 Support functions in this section which have multiple modes of failure C<die>
4345 on error; the rest simply return a false value.
4347 The user-interface functions (all of the C<cmd_*> functions) just output
4352 The C<%set> hash defines the mapping from command letter to subroutine
4355 C<%set> is a two-level hash, indexed by set name and then by command name.
4356 Note that trying to set the CommandSet to C<foobar> simply results in the
4357 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
4366 'A' => 'pre580_null',
4368 'B' => 'pre580_null',
4369 'd' => 'pre580_null',
4372 'M' => 'pre580_null',
4374 'o' => 'pre580_null',
4380 '<' => 'pre590_prepost',
4381 '<<' => 'pre590_prepost',
4382 '>' => 'pre590_prepost',
4383 '>>' => 'pre590_prepost',
4384 '{' => 'pre590_prepost',
4385 '{{' => 'pre590_prepost',
4389 my %breakpoints_data;
4391 sub _has_breakpoint_data_ref {
4392 my ($filename, $line) = @_;
4395 exists( $breakpoints_data{$filename} )
4397 exists( $breakpoints_data{$filename}{$line} )
4401 sub _get_breakpoint_data_ref {
4402 my ($filename, $line) = @_;
4404 return ($breakpoints_data{$filename}{$line} ||= +{});
4407 sub _delete_breakpoint_data_ref {
4408 my ($filename, $line) = @_;
4410 delete($breakpoints_data{$filename}{$line});
4411 if (! scalar(keys( %{$breakpoints_data{$filename}} )) ) {
4412 delete($breakpoints_data{$filename});
4418 sub _set_breakpoint_enabled_status {
4419 my ($filename, $line, $status) = @_;
4421 _get_breakpoint_data_ref($filename, $line)->{'enabled'} =
4428 sub _enable_breakpoint_temp_enabled_status {
4429 my ($filename, $line) = @_;
4431 _get_breakpoint_data_ref($filename, $line)->{'temp_enabled'} = 1;
4436 sub _cancel_breakpoint_temp_enabled_status {
4437 my ($filename, $line) = @_;
4439 my $ref = _get_breakpoint_data_ref($filename, $line);
4441 delete ($ref->{'temp_enabled'});
4444 _delete_breakpoint_data_ref($filename, $line);
4450 sub _is_breakpoint_enabled {
4451 my ($filename, $line) = @_;
4453 my $data_ref = _get_breakpoint_data_ref($filename, $line);
4454 return ($data_ref->{'enabled'} || $data_ref->{'temp_enabled'});
4457 =head2 C<cmd_wrapper()> (API)
4459 C<cmd_wrapper()> allows the debugger to switch command sets
4460 depending on the value of the C<CommandSet> option.
4462 It tries to look up the command in the C<%set> package-level I<lexical>
4463 (which means external entities can't fiddle with it) and create the name of
4464 the sub to call based on the value found in the hash (if it's there). I<All>
4465 of the commands to be handled in a set have to be added to C<%set>; if they
4466 aren't found, the 5.8.0 equivalent is called (if there is one).
4468 This code uses symbolic references.
4475 my $dblineno = shift;
4477 # Assemble the command subroutine's name by looking up the
4478 # command set and command name in %set. If we can't find it,
4479 # default to the older version of the command.
4481 . ( $set{$CommandSet}{$cmd}
4482 || ( $cmd =~ /\A[<>{]+/o ? 'prepost' : $cmd ) );
4484 # Call the command subroutine, call it by name.
4485 return __PACKAGE__->can($call)->( $cmd, $line, $dblineno );
4486 } ## end sub cmd_wrapper
4488 =head3 C<cmd_a> (command)
4490 The C<a> command handles pre-execution actions. These are associated with a
4491 particular line, so they're stored in C<%dbline>. We default to the current
4492 line if none is specified.
4498 my $line = shift || ''; # [.|line] expr
4501 # If it's dot (here), or not all digits, use the current line.
4502 $line =~ s/\A\./$dbline/;
4504 # Should be a line number followed by an expression.
4505 if ( my ($lineno, $expr) = $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
4507 if (! length($lineno)) {
4511 # If we have an expression ...
4512 if ( length $expr ) {
4514 # ... but the line isn't breakable, complain.
4515 if ( $dbline[$lineno] == 0 ) {
4517 "Line $lineno($dbline[$lineno]) does not have an action?\n";
4521 # It's executable. Record that the line has an action.
4522 $had_breakpoints{$filename} |= 2;
4524 # Remove any action, temp breakpoint, etc.
4525 $dbline{$lineno} =~ s/\0[^\0]*//;
4527 # Add the action to the line.
4528 $dbline{$lineno} .= "\0" . action($expr);
4530 _set_breakpoint_enabled_status($filename, $lineno, 1);
4532 } ## end if (length $expr)
4533 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
4538 "Adding an action requires an optional lineno and an expression\n"
4543 =head3 C<cmd_A> (command)
4545 Delete actions. Similar to above, except the delete code is in a separate
4546 subroutine, C<delete_action>.
4552 my $line = shift || '';
4556 $line =~ s/^\./$dbline/;
4558 # Call delete_action with a null param to delete them all.
4559 # The '1' forces the eval to be true. It'll be false only
4560 # if delete_action blows up for some reason, in which case
4561 # we print $@ and get out.
4562 if ( $line eq '*' ) {
4563 if (! eval { _delete_all_actions(); 1 }) {
4569 # There's a real line number. Pass it to delete_action.
4570 # Error trapping is as above.
4571 elsif ( $line =~ /^(\S.*)/ ) {
4572 if (! eval { delete_action($1); 1 }) {
4578 # Swing and a miss. Bad syntax.
4581 "Deleting an action requires a line number, or '*' for all\n" ; # hint
4585 =head3 C<delete_action> (API)
4587 C<delete_action> accepts either a line number or C<undef>. If a line number
4588 is specified, we check for the line being executable (if it's not, it
4589 couldn't have had an action). If it is, we just take the action off (this
4590 will get any kind of an action, including breakpoints).
4594 sub _remove_action_from_dbline {
4597 $dbline{$i} =~ s/\0[^\0]*//; # \^a
4598 delete $dbline{$i} if $dbline{$i} eq '';
4603 sub _delete_all_actions {
4604 print {$OUT} "Deleting all actions...\n";
4606 for my $file ( keys %had_breakpoints ) {
4607 local *dbline = $main::{ '_<' . $file };
4610 for my $i (1 .. $max) {
4611 if ( defined $dbline{$i} ) {
4612 _remove_action_from_dbline($i);
4616 unless ( $had_breakpoints{$file} &= ~2 ) {
4617 delete $had_breakpoints{$file};
4627 if ( defined($i) ) {
4629 die "Line $i has no action .\n" if $dbline[$i] == 0;
4631 # Nuke whatever's there.
4632 _remove_action_from_dbline($i);
4635 _delete_all_actions();
4639 =head3 C<cmd_b> (command)
4641 Set breakpoints. Since breakpoints can be set in so many places, in so many
4642 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4643 we try to parse the command type, and then shuttle it off to an appropriate
4644 subroutine to actually do the work of setting the breakpoint in the right
4651 my $line = shift; # [.|line] [cond]
4654 my $default_cond = sub {
4656 return length($cond) ? $cond : '1';
4659 # Make . the current line number if it's there..
4660 $line =~ s/^\.(\s|\z)/$dbline$1/;
4662 # No line number, no condition. Simple break on current line.
4663 if ( $line =~ /^\s*$/ ) {
4664 cmd_b_line( $dbline, 1 );
4667 # Break on load for a file.
4668 elsif ( my ($file) = $line =~ /^load\b\s*(.*)/ ) {
4673 # b compile|postpone <some sub> [<condition>]
4674 # The interpreter actually traps this one for us; we just put the
4675 # necessary condition in the %postponed hash.
4676 elsif ( my ($action, $subname, $cond)
4677 = $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4679 # De-Perl4-ify the name - ' separators to ::.
4680 $subname =~ s/'/::/g;
4682 # Qualify it into the current package unless it's already qualified.
4683 $subname = "${package}::" . $subname unless $subname =~ /::/;
4685 # Add main if it starts with ::.
4686 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4688 # Save the break type for this sub.
4689 $postponed{$subname} = (($action eq 'postpone')
4690 ? ( "break +0 if " . $default_cond->($cond) )
4692 } ## end elsif ($line =~ ...
4693 # b <filename>:<line> [<condition>]
4694 elsif (my ($filename, $line_num, $cond)
4695 = $line =~ /\A(\S+[^:]):(\d+)\s*(.*)/ms) {
4696 cmd_b_filename_line(
4699 (length($cond) ? $cond : '1'),
4702 # b <sub name> [<condition>]
4703 elsif ( my ($new_subname, $new_cond) =
4704 $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4707 $subname = $new_subname;
4708 cmd_b_sub( $subname, $default_cond->($new_cond) );
4711 # b <line> [<condition>].
4712 elsif ( my ($line_n, $cond) = $line =~ /^(\d*)\s*(.*)/ ) {
4714 # Capture the line. If none, it's the current line.
4715 $line = $line_n || $dbline;
4718 cmd_b_line( $line, $default_cond->($cond) );
4721 # Line didn't make sense.
4723 print "confused by line($line)?\n";
4729 =head3 C<break_on_load> (API)
4731 We want to break when this file is loaded. Mark this file in the
4732 C<%break_on_load> hash, and note that it has a breakpoint in
4733 C<%had_breakpoints>.
4739 $break_on_load{$file} = 1;
4740 $had_breakpoints{$file} |= 1;
4743 =head3 C<report_break_on_load> (API)
4745 Gives us an array of filenames that are set to break on load. Note that
4746 only files with break-on-load are in here, so simply showing the keys
4751 sub report_break_on_load {
4752 sort keys %break_on_load;
4755 =head3 C<cmd_b_load> (command)
4757 We take the file passed in and try to find it in C<%INC> (which maps modules
4758 to files they came from). We mark those files for break-on-load via
4759 C<break_on_load> and then report that it was done.
4767 # This is a block because that way we can use a redo inside it
4768 # even without there being any looping structure at all outside it.
4771 # Save short name and full path if found.
4773 push @files, $::INC{$file} if $::INC{$file};
4775 # Tack on .pm and do it again unless there was a '.' in the name
4777 $file .= '.pm', redo unless $file =~ /\./;
4780 # Do the real work here.
4781 break_on_load($_) for @files;
4783 # All the files that have break-on-load breakpoints.
4784 @files = report_break_on_load;
4786 # Normalize for the purposes of our printing this.
4789 print $OUT "Will stop on load of '@files'.\n";
4790 } ## end sub cmd_b_load
4792 =head3 C<$filename_error> (API package global)
4794 Several of the functions we need to implement in the API need to work both
4795 on the current file and on other files. We don't want to duplicate code, so
4796 C<$filename_error> is used to contain the name of the file that's being
4797 worked on (if it's not the current one).
4799 We can now build functions in pairs: the basic function works on the current
4800 file, and uses C<$filename_error> as part of its error message. Since this is
4801 initialized to C<"">, no filename will appear when we are working on the
4804 The second function is a wrapper which does the following:
4810 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4814 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4818 Calls the first function.
4820 The first function works on the I<current> file (i.e., the one we changed to),
4821 and prints C<$filename_error> in the error message (the name of the other file)
4822 if it needs to. When the functions return, C<*dbline> is restored to point
4823 to the actual current file (the one we're executing in) and
4824 C<$filename_error> is restored to C<"">. This restores everything to
4825 the way it was before the second function was called at all.
4827 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4834 use vars qw($filename_error);
4835 $filename_error = '';
4837 =head3 breakable_line(from, to) (API)
4839 The subroutine decides whether or not a line in the current file is breakable.
4840 It walks through C<@dbline> within the range of lines specified, looking for
4841 the first line that is breakable.
4843 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4844 first line I<after> C<$to> that's breakable, if there is one.
4846 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4847 first line I<before> C<$to> that's breakable, if there is one.
4851 sub breakable_line {
4853 my ( $from, $to ) = @_;
4855 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4858 # If there are at least 2 arguments, we're trying to search a range.
4861 # $delta is positive for a forward search, negative for a backward one.
4862 my $delta = $from < $to ? +1 : -1;
4864 # Keep us from running off the ends of the file.
4865 my $limit = $delta > 0 ? $#dbline : 1;
4867 # Clever test. If you're a mathematician, it's obvious why this
4868 # test works. If not:
4869 # If $delta is positive (going forward), $limit will be $#dbline.
4870 # If $to is less than $limit, ($limit - $to) will be positive, times
4871 # $delta of 1 (positive), so the result is > 0 and we should use $to
4872 # as the stopping point.
4874 # If $to is greater than $limit, ($limit - $to) is negative,
4875 # times $delta of 1 (positive), so the result is < 0 and we should
4876 # use $limit ($#dbline) as the stopping point.
4878 # If $delta is negative (going backward), $limit will be 1.
4879 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4880 # (negative) so the result is > 0, and we use $to as the stopping
4883 # If $to is less than zero, ($limit - $to) will be positive,
4884 # times $delta of -1 (negative), so the result is not > 0, and
4885 # we use $limit (1) as the stopping point.
4887 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4888 # (negative), still giving zero; the result is not > 0, and
4889 # we use $limit (1) as the stopping point.
4891 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4892 # (negative), giving a positive (>0) value, so we'll set $limit to
4895 $limit = $to if ( $limit - $to ) * $delta > 0;
4897 # The real search loop.
4898 # $i starts at $from (the point we want to start searching from).
4899 # We move through @dbline in the appropriate direction (determined
4900 # by $delta: either -1 (back) or +1 (ahead).
4901 # We stay in as long as we haven't hit an executable line
4902 # ($dbline[$i] == 0 means not executable) and we haven't reached
4903 # the limit yet (test similar to the above).
4904 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4906 } ## end if (@_ >= 2)
4908 # If $i points to a line that is executable, return that.
4909 return $i unless $dbline[$i] == 0;
4911 # Format the message and print it: no breakable lines in range.
4912 my ( $pl, $upto ) = ( '', '' );
4913 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4915 # If there's a filename in filename_error, we'll see it.
4917 die "Line$pl $from$upto$filename_error not breakable\n";
4918 } ## end sub breakable_line
4920 =head3 breakable_line_in_filename(file, from, to) (API)
4922 Like C<breakable_line>, but look in another file.
4926 sub breakable_line_in_filename {
4928 # Capture the file name.
4931 # Swap the magic line array over there temporarily.
4932 local *dbline = $main::{ '_<' . $f };
4934 # If there's an error, it's in this other file.
4935 local $filename_error = " of '$f'";
4937 # Find the breakable line.
4940 # *dbline and $filename_error get restored when this block ends.
4942 } ## end sub breakable_line_in_filename
4944 =head3 break_on_line(lineno, [condition]) (API)
4946 Adds a breakpoint with the specified condition (or 1 if no condition was
4947 specified) to the specified line. Dies if it can't.
4953 my $cond = @_ ? shift(@_) : 1;
4959 # Woops, not a breakable line. $filename_error allows us to say
4960 # if it was in a different file.
4961 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4963 # Mark this file as having breakpoints in it.
4964 $had_breakpoints{$filename} |= 1;
4966 # If there is an action or condition here already ...
4967 if ( $dbline{$i} ) {
4969 # ... swap this condition for the existing one.
4970 $dbline{$i} =~ s/^[^\0]*/$cond/;
4974 # Nothing here - just add the condition.
4975 $dbline{$i} = $cond;
4977 _set_breakpoint_enabled_status($filename, $i, 1);
4981 } ## end sub break_on_line
4983 =head3 cmd_b_line(line, [condition]) (command)
4985 Wrapper for C<break_on_line>. Prints the failure message if it
4991 if (not eval { break_on_line(@_); 1 }) {
4993 print $OUT $@ and return;
4997 } ## end sub cmd_b_line
4999 =head3 cmd_b_filename_line(line, [condition]) (command)
5001 Wrapper for C<break_on_filename_line>. Prints the failure message if it
5006 sub cmd_b_filename_line {
5007 if (not eval { break_on_filename_line(@_); 1 }) {
5009 print $OUT $@ and return;
5015 =head3 break_on_filename_line(file, line, [condition]) (API)
5017 Switches to the file specified and then calls C<break_on_line> to set
5022 sub break_on_filename_line {
5025 my $cond = @_ ? shift(@_) : 1;
5027 # Switch the magical hash temporarily.
5028 local *dbline = $main::{ '_<' . $f };
5030 # Localize the variables that break_on_line uses to make its message.
5031 local $filename_error = " of '$f'";
5032 local $filename = $f;
5034 # Add the breakpoint.
5035 break_on_line( $i, $cond );
5038 } ## end sub break_on_filename_line
5040 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
5042 Switch to another file, search the range of lines specified for an
5043 executable one, and put a breakpoint on the first one you find.
5047 sub break_on_filename_line_range {
5051 my $cond = @_ ? shift(@_) : 1;
5053 # Find a breakable line if there is one.
5054 my $i = breakable_line_in_filename( $f, $from, $to );
5056 # Add the breakpoint.
5057 break_on_filename_line( $f, $i, $cond );
5060 } ## end sub break_on_filename_line_range
5062 =head3 subroutine_filename_lines(subname, [condition]) (API)
5064 Search for a subroutine within a given file. The condition is ignored.
5065 Uses C<find_sub> to locate the desired subroutine.
5069 sub subroutine_filename_lines {
5070 my ( $subname ) = @_;
5072 # Returned value from find_sub() is fullpathname:startline-endline.
5073 # The match creates the list (fullpathname, start, end).
5074 return (find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/);
5075 } ## end sub subroutine_filename_lines
5077 =head3 break_subroutine(subname) (API)
5079 Places a break on the first line possible in the specified subroutine. Uses
5080 C<subroutine_filename_lines> to find the subroutine, and
5081 C<break_on_filename_line_range> to place the break.
5085 sub break_subroutine {
5086 my $subname = shift;
5088 # Get filename, start, and end.
5089 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
5090 or die "Subroutine $subname not found.\n";
5093 # Null condition changes to '1' (always true).
5094 my $cond = @_ ? shift(@_) : 1;
5096 # Put a break the first place possible in the range of lines
5097 # that make up this subroutine.
5098 break_on_filename_line_range( $file, $s, $e, $cond );
5101 } ## end sub break_subroutine
5103 =head3 cmd_b_sub(subname, [condition]) (command)
5105 We take the incoming subroutine name and fully-qualify it as best we can.
5109 =item 1. If it's already fully-qualified, leave it alone.
5111 =item 2. Try putting it in the current package.
5113 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
5115 =item 4. If it starts with '::', put it in 'main::'.
5119 After all this cleanup, we call C<break_subroutine> to try to set the
5125 my $subname = shift;
5126 my $cond = @_ ? shift : 1;
5128 # If the subname isn't a code reference, qualify it so that
5129 # break_subroutine() will work right.
5130 if ( ref($subname) ne 'CODE' ) {
5133 $subname =~ s/'/::/g;
5136 # Put it in this package unless it's already qualified.
5137 if ($subname !~ /::/)
5139 $subname = $package . '::' . $subname;
5142 # Requalify it into CORE::GLOBAL if qualifying it into this
5143 # package resulted in its not being defined, but only do so
5144 # if it really is in CORE::GLOBAL.
5145 my $core_name = "CORE::GLOBAL::$s";
5146 if ((!defined(&$subname))
5148 and (defined &{$core_name}))
5150 $subname = $core_name;
5153 # Put it in package 'main' if it has a leading ::.
5154 if ($subname =~ /\A::/)
5156 $subname = "main" . $subname;
5158 } ## end if ( ref($subname) ne 'CODE' ) {
5160 # Try to set the breakpoint.
5161 if (not eval { break_subroutine( $subname, $cond ); 1 }) {
5168 } ## end sub cmd_b_sub
5170 =head3 C<cmd_B> - delete breakpoint(s) (command)
5172 The command mostly parses the command line and tries to turn the argument
5173 into a line spec. If it can't, it uses the current line. It then calls
5174 C<delete_breakpoint> to actually do the work.
5176 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
5177 thereby deleting all the breakpoints.
5184 # No line spec? Use dbline.
5185 # If there is one, use it if it's non-zero, or wipe it out if it is.
5186 my $line = ( $_[0] =~ /\A\./ ) ? $dbline : (shift || '');
5189 # If the line was dot, make the line the current one.
5190 $line =~ s/^\./$dbline/;
5192 # If it's * we're deleting all the breakpoints.
5193 if ( $line eq '*' ) {
5194 if (not eval { delete_breakpoint(); 1 }) {
5199 # If there is a line spec, delete the breakpoint on that line.
5200 elsif ( $line =~ /\A(\S.*)/ ) {
5201 if (not eval { delete_breakpoint( $line || $dbline ); 1 }) {
5205 } ## end elsif ($line =~ /^(\S.*)/)
5210 "Deleting a breakpoint requires a line number, or '*' for all\n"
5217 =head3 delete_breakpoint([line]) (API)
5219 This actually does the work of deleting either a single breakpoint, or all
5222 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
5223 just drop out with a message saying so. If it is, we remove the condition
5224 part of the 'condition\0action' that says there's a breakpoint here. If,
5225 after we've done that, there's nothing left, we delete the corresponding
5226 line in C<%dbline> to signal that no action needs to be taken for this line.
5228 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
5229 which lists all currently-loaded files which have breakpoints. We then look
5230 at each line in each of these files, temporarily switching the C<%dbline>
5231 and C<@dbline> structures to point to the files in question, and do what
5232 we did in the single line case: delete the condition in C<@dbline>, and
5233 delete the key in C<%dbline> if nothing's left.
5235 We then wholesale delete C<%postponed>, C<%postponed_file>, and
5236 C<%break_on_load>, because these structures contain breakpoints for files
5237 and code that haven't been loaded yet. We can just kill these off because there
5238 are no magical debugger structures associated with them.
5242 sub _remove_breakpoint_entry {
5246 _delete_breakpoint_data_ref($fn, $i);
5251 sub _delete_all_breakpoints {
5252 print {$OUT} "Deleting all breakpoints...\n";
5254 # %had_breakpoints lists every file that had at least one
5256 for my $fn ( keys %had_breakpoints ) {
5258 # Switch to the desired file temporarily.
5259 local *dbline = $main::{ '_<' . $fn };
5263 # For all lines in this file ...
5264 for my $i (1 .. $max) {
5266 # If there's a breakpoint or action on this line ...
5267 if ( defined $dbline{$i} ) {
5269 # ... remove the breakpoint.
5270 $dbline{$i} =~ s/\A[^\0]+//;
5271 if ( $dbline{$i} =~ s/\A\0?\z// ) {
5272 # Remove the entry altogether if no action is there.
5273 _remove_breakpoint_entry($fn, $i);
5275 } ## end if (defined $dbline{$i...
5276 } ## end for $i (1 .. $max)
5278 # If, after we turn off the "there were breakpoints in this file"
5279 # bit, the entry in %had_breakpoints for this file is zero,
5280 # we should remove this file from the hash.
5281 if ( not $had_breakpoints{$fn} &= (~1) ) {
5282 delete $had_breakpoints{$fn};
5284 } ## end for my $fn (keys %had_breakpoints)
5286 # Kill off all the other breakpoints that are waiting for files that
5287 # haven't been loaded yet.
5289 undef %postponed_file;
5290 undef %break_on_load;
5295 sub _delete_breakpoint_from_line {
5298 # Woops. This line wasn't breakable at all.
5299 die "Line $i not breakable.\n" if $dbline[$i] == 0;
5301 # Kill the condition, but leave any action.
5302 $dbline{$i} =~ s/\A[^\0]*//;
5304 # Remove the entry entirely if there's no action left.
5305 if ($dbline{$i} eq '') {
5306 _remove_breakpoint_entry($filename, $i);
5312 sub delete_breakpoint {
5315 # If we got a line, delete just that one.
5316 if ( defined($i) ) {
5317 _delete_breakpoint_from_line($i);
5319 # No line; delete them all.
5321 _delete_all_breakpoints();
5327 =head3 cmd_stop (command)
5329 This is meant to be part of the new command API, but it isn't called or used
5330 anywhere else in the debugger. XXX It is probably meant for use in development
5335 sub cmd_stop { # As on ^C, but not signal-safy.
5339 =head3 C<cmd_e> - threads
5341 Display the current thread id:
5345 This could be how (when implemented) to send commands to this thread id (e cmd)
5346 or that thread id (e tid cmd).
5353 unless (exists($INC{'threads.pm'})) {
5354 print "threads not loaded($ENV{PERL5DB_THREADED})
5355 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5357 my $tid = threads->tid;
5358 print "thread id: $tid\n";
5362 =head3 C<cmd_E> - list of thread ids
5364 Display the list of available thread ids:
5368 This could be used (when implemented) to send commands to all threads (E cmd).
5375 unless (exists($INC{'threads.pm'})) {
5376 print "threads not loaded($ENV{PERL5DB_THREADED})
5377 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5379 my $tid = threads->tid;
5380 print "thread ids: ".join(', ',
5381 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
5386 =head3 C<cmd_h> - help command (command)
5388 Does the work of either
5394 Showing all the debugger help
5398 Showing help for a specific command
5405 use vars qw($summary);
5410 # If we have no operand, assume null.
5411 my $line = shift || '';
5413 # 'h h'. Print the long-format help.
5414 if ( $line =~ /\Ah\s*\z/ ) {
5418 # 'h <something>'. Search for the command and print only its help.
5419 elsif ( my ($asked) = $line =~ /\A(\S.*)\z/ ) {
5421 # support long commands; otherwise bogus errors
5422 # happen when you ask for h on <CR> for example
5423 my $qasked = quotemeta($asked); # for searching; we don't
5424 # want to use it as a pattern.
5425 # XXX: finds CR but not <CR>
5427 # Search the help string for the command.
5429 $help =~ /^ # Start of a line
5431 (?:[IB]<) # Optional markup
5432 $qasked # The requested command
5437 # It's there; pull it out and print it.
5441 (?:[IB]<) # Optional markup
5442 $qasked # The command
5443 ([\s\S]*?) # Description line(s)
5444 \n) # End of last description line
5445 (?!\s) # Next line not starting with
5454 # Not found; not a debugger command.
5456 print_help("B<$asked> is not a debugger command.\n");
5458 } ## end elsif ($line =~ /^(\S.*)$/)
5460 # 'h' - print the summary help.
5462 print_help($summary);
5466 =head3 C<cmd_i> - inheritance display
5468 Display the (nested) parentage of the module or object given.
5475 foreach my $isa ( split( /\s+/, $line ) ) {
5477 # The &-call is here to ascertain the mutability of @_.
5485 defined( ${"$_\::VERSION"} )
5486 ? ' ' . ${"$_\::VERSION"}
5488 } @{mro::get_linear_isa(ref($isa) || $isa)}
5494 =head3 C<cmd_l> - list lines (command)
5496 Most of the command is taken up with transforming all the different line
5497 specification syntaxes into 'start-stop'. After that is done, the command
5498 runs a loop over C<@dbline> for the specified range of lines. It handles
5499 the printing of each line and any markers (C<==E<gt>> for current line,
5500 C<b> for break on this line, C<a> for action on this line, C<:> for this
5503 We save the last line listed in the C<$start> global for further listing
5510 foreach my $v (@_) {
5520 foreach my $v (@_) {
5528 sub _minify_to_max {
5531 $$ref = _min($$ref, $max);
5536 sub _cmd_l_handle_var_name {
5537 my $var_name = shift;
5539 $evalarg = $var_name;
5541 my ($s) = DB::eval();
5543 # Ooops. Bad scalar.
5545 print {$OUT} "Error: $@\n";
5549 # Good scalar. If it's a reference, find what it points to.
5551 print {$OUT} "Interpreted as: $1 $s\n";
5554 # Call self recursively to really do the command.
5555 return _cmd_l_main( $s );
5558 sub _cmd_l_handle_subname {
5563 $subname =~ s/\'/::/;
5565 # Put it in this package unless it starts with ::.
5566 $subname = $package . "::" . $subname unless $subname =~ /::/;
5568 # Put it in CORE::GLOBAL if t doesn't start with :: and
5569 # it doesn't live in this package and it lives in CORE::GLOBAL.
5570 $subname = "CORE::GLOBAL::$s"
5571 if not defined &$subname
5573 and defined &{"CORE::GLOBAL::$s"};
5575 # Put leading '::' names into 'main::'.
5576 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
5578 # Get name:start-stop from find_sub, and break this up at
5580 my @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
5582 # Pull off start-stop.
5583 my $subrange = pop @pieces;
5585 # If the name contained colons, the split broke it up.
5586 # Put it back together.
5587 $file = join( ':', @pieces );
5589 # If we're not in that file, switch over to it.
5590 if ( $file ne $filename ) {
5591 if (! $slave_editor) {
5592 print {$OUT} "Switching to file '$file'.\n";
5595 # Switch debugger's magic structures.
5596 *dbline = $main::{ '_<' . $file };
5599 } ## end if ($file ne $filename)
5601 # Subrange is 'start-stop'. If this is less than a window full,
5602 # swap it to 'start+', which will list a window from the start point.
5604 if ( eval($subrange) < -$window ) {
5605 $subrange =~ s/-.*/+/;
5608 # Call self recursively to list the range.
5609 return _cmd_l_main( $subrange );
5610 } ## end if ($subrange)
5614 print {$OUT} "Subroutine $subname not found.\n";
5620 # Compute new range to list.
5621 $incr = $window - 1;
5624 return _cmd_l_main( $start . '-' . ( $start + $incr ) );
5628 my ($new_start, $new_incr) = @_;
5630 # Don't reset start for 'l +nnn'.
5631 $start = $new_start if $new_start;
5633 # Increment for list. Use window size if not specified.
5634 # (Allows 'l +' to work.)
5635 $incr = $new_incr || ($window - 1);
5637 # Create a line range we'll understand, and recurse to do it.
5638 return _cmd_l_main( $start . '-' . ( $start + $incr ) );
5641 sub _cmd_l_calc_initial_end_and_i {
5642 my ($spec, $start_match, $end_match) = @_;
5644 # Determine end point; use end of file if not specified.
5645 my $end = ( !defined $start_match ) ? $max :
5646 ( $end_match ? $end_match : $start_match );
5648 # Go on to the end, and then stop.
5649 _minify_to_max(\$end);
5651 # Determine start line.
5652 my $i = $start_match;
5666 my ($spec, $current_line, $start_match, $end_match) = @_;
5669 _cmd_l_calc_initial_end_and_i($spec, $start_match, $end_match);
5671 # If we're running under a slave editor, force it to show the lines.
5672 if ($slave_editor) {
5673 print {$OUT} "\032\032$filename:$i:0\n";
5676 # We're doing it ourselves. We want to show the line and special
5678 # - the current line in execution
5679 # - whether a line is breakable or not
5680 # - whether a line has a break or not
5681 # - whether a line has an action or not
5684 for ( ; $i <= $end ; $i++ ) {
5686 # Check for breakpoints and actions.
5687 my ( $stop, $action );
5689 ( $stop, $action ) = split( /\0/, $dbline{$i} );
5692 # ==> if this is the current line in execution,
5693 # : if it's breakable.
5695 ( $i == $current_line and $filename eq $filename_ini )
5697 : ( $dbline[$i] + 0 ? ':' : ' ' );
5699 # Add break and action indicators.
5700 $arrow .= 'b' if $stop;
5701 $arrow .= 'a' if $action;
5704 print {$OUT} "$i$arrow\t", $dbline[$i];
5706 # Move on to the next line. Drop out on an interrupt.
5711 } ## end for (; $i <= $end ; $i++)
5713 # Line the prompt up; print a newline if the last line listed
5714 # didn't have a newline.
5715 if ($dbline[ $i - 1 ] !~ /\n\z/) {
5718 } ## end else [ if ($slave_editor)
5720 # Save the point we last listed to in case another relative 'l'
5721 # command is desired. Don't let it run off the end.
5723 _minify_to_max(\$start);
5731 # If this is '-something', delete any spaces after the dash.
5732 $spec =~ s/\A-\s*\z/-/;
5734 # If the line is '$something', assume this is a scalar containing a
5736 # Set up for DB::eval() - evaluate in *user* context.
5737 if ( my ($var_name) = $spec =~ /\A(\$.*)/s ) {
5738 return _cmd_l_handle_var_name($var_name);
5740 # l name. Try to find a sub by that name.
5741 elsif ( ($subname) = $spec =~ /\A([\':A-Za-z_][\':\w]*(?:\[.*\])?)/s ) {
5742 return _cmd_l_handle_subname();
5745 elsif ( $spec !~ /\S/ ) {
5746 return _cmd_l_empty();
5748 # l [start]+number_of_lines
5749 elsif ( my ($new_start, $new_incr) = $spec =~ /\A(\d*)\+(\d*)\z/ ) {
5750 return _cmd_l_plus($new_start, $new_incr);
5752 # l start-stop or l start,stop
5753 elsif (my ($s, $e) = $spec =~ /^(?:(-?[\d\$\.]+)(?:[-,]([\d\$\.]+))?)?/ ) {
5754 return _cmd_l_range($spec, $line, $s, $e);
5761 my (undef, $line) = @_;
5763 return _cmd_l_main($line);
5766 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5768 To list breakpoints, the command has to look determine where all of them are
5769 first. It starts a C<%had_breakpoints>, which tells us what all files have
5770 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5771 magic source and breakpoint data structures) to the file, and then look
5772 through C<%dbline> for lines with breakpoints and/or actions, listing them
5773 out. We look through C<%postponed> not-yet-compiled subroutines that have
5774 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5775 that have breakpoints.
5777 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5781 sub _cmd_L_calc_arg {
5782 # If no argument, list everything. Pre-5.8.0 version always lists
5784 my $arg = shift || 'abw';
5785 if ($CommandSet ne '580')
5793 sub _cmd_L_calc_wanted_flags {
5794 my $arg = _cmd_L_calc_arg(shift);
5796 return (map { index($arg, $_) >= 0 ? 1 : 0 } qw(a b w));
5800 sub _cmd_L_handle_breakpoints {
5801 my ($handle_db_line) = @_;
5804 # Look in all the files with breakpoints...
5805 for my $file ( keys %had_breakpoints ) {
5807 # Temporary switch to this file.
5808 local *dbline = $main::{ '_<' . $file };
5810 # Set up to look through the whole file.
5812 my $was; # Flag: did we print something
5815 # For each line in the file ...
5816 for my $i (1 .. $max) {
5818 # We've got something on this line.
5819 if ( defined $dbline{$i} ) {
5821 # Print the header if we haven't.
5823 print {$OUT} "$file:\n";
5827 print {$OUT} " $i:\t", $dbline[$i];
5829 $handle_db_line->($dbline{$i});
5831 # Quit if the user hit interrupt.
5833 last BREAKPOINTS_SCAN;
5835 } ## end if (defined $dbline{$i...
5836 } ## end for my $i (1 .. $max)
5837 } ## end for my $file (keys %had_breakpoints)
5842 sub _cmd_L_handle_postponed_breakpoints {
5843 my ($handle_db_line) = @_;
5845 print {$OUT} "Postponed breakpoints in files:\n";
5848 for my $file ( keys %postponed_file ) {
5849 my $db = $postponed_file{$file};
5850 print {$OUT} " $file:\n";
5851 for my $line ( sort { $a <=> $b } keys %$db ) {
5852 print {$OUT} " $line:\n";
5854 $handle_db_line->($db->{$line});
5857 last POSTPONED_SCANS;
5861 last POSTPONED_SCANS;
5872 my ($action_wanted, $break_wanted, $watch_wanted) =
5873 _cmd_L_calc_wanted_flags(shift);
5875 my $handle_db_line = sub {
5878 my ( $stop, $action ) = split( /\0/, $l );
5880 if ($stop and $break_wanted) {
5881 print {$OUT} " break if (", $stop, ")\n"
5884 if ($action && $action_wanted) {
5885 print {$OUT} " action: ", $action, "\n"
5891 # Breaks and actions are found together, so we look in the same place
5893 if ( $break_wanted or $action_wanted ) {
5894 _cmd_L_handle_breakpoints($handle_db_line);
5897 # Look for breaks in not-yet-compiled subs:
5898 if ( %postponed and $break_wanted ) {
5899 print {$OUT} "Postponed breakpoints in subroutines:\n";
5902 for $subname ( keys %postponed ) {
5903 print {$OUT} " $subname\t$postponed{$subname}\n";
5908 } ## end if (%postponed and $break_wanted)
5910 # Find files that have not-yet-loaded breaks:
5911 my @have = map { # Combined keys
5912 keys %{ $postponed_file{$_} }
5913 } keys %postponed_file;
5915 # If there are any, list them.
5916 if ( @have and ( $break_wanted or $action_wanted ) ) {
5917 _cmd_L_handle_postponed_breakpoints($handle_db_line);
5918 } ## end if (@have and ($break_wanted...
5920 if ( %break_on_load and $break_wanted ) {
5921 print {$OUT} "Breakpoints on load:\n";
5922 BREAK_ON_LOAD: for my $filename ( keys %break_on_load ) {
5923 print {$OUT} " $filename\n";
5924 last BREAK_ON_LOAD if $signal;
5926 } ## end if (%break_on_load and...
5928 if ($watch_wanted and ( $trace & 2 )) {
5929 print {$OUT} "Watch-expressions:\n" if @to_watch;
5930 TO_WATCH: for my $expr (@to_watch) {
5931 print {$OUT} " $expr\n";
5932 last TO_WATCH if $signal;
5939 =head3 C<cmd_M> - list modules (command)
5941 Just call C<list_modules>.
5951 =head3 C<cmd_o> - options (command)
5953 If this is just C<o> by itself, we list the current settings via
5954 C<dump_option>. If there's a nonblank value following it, we pass that on to
5955 C<parse_options> for processing.
5961 my $opt = shift || ''; # opt[=val]
5963 # Nonblank. Try to parse and process.
5964 if ( $opt =~ /^(\S.*)/ ) {
5968 # Blank. List the current option settings.
5976 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5978 Advises the user that the O command has been renamed.
5983 print $OUT "The old O command is now the o command.\n"; # hint
5984 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5985 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5988 =head3 C<cmd_v> - view window (command)
5990 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5991 move back a few lines to list the selected line in context. Uses C<cmd_l>
5992 to do the actual listing after figuring out the range of line to request.
5996 use vars qw($preview);
6002 # Extract the line to list around. (Astute readers will have noted that
6003 # this pattern will match whether or not a numeric line is specified,
6004 # which means that we'll always enter this loop (though a non-numeric
6005 # argument results in no action at all)).
6006 if ( $line =~ /^(\d*)$/ ) {
6008 # Total number of lines to list (a windowful).
6009 $incr = $window - 1;
6011 # Set the start to the argument given (if there was one).
6014 # Back up by the context amount.
6017 # Put together a linespec that cmd_l will like.
6018 $line = $start . '-' . ( $start + $incr );
6021 cmd_l( 'l', $line );
6022 } ## end if ($line =~ /^(\d*)$/)
6025 =head3 C<cmd_w> - add a watch expression (command)
6027 The 5.8 version of this command adds a watch expression if one is specified;
6028 it does nothing if entered with no operands.
6030 We extract the expression, save it, evaluate it in the user's context, and
6031 save the value. We'll re-evaluate it each time the debugger passes a line,
6032 and will stop (see the code at the top of the command loop) if the value
6033 of any of the expressions changes.
6037 sub _add_watch_expr {
6041 push @to_watch, $expr;
6043 # Parameterize DB::eval and call it to get the expression's value
6044 # in the user's context. This version can handle expressions which
6045 # return a list value.
6047 # The &-call is here to ascertain the mutability of @_.
6048 my ($val) = join( ' ', &DB::eval);
6049 $val = ( defined $val ) ? "'$val'" : 'undef';
6051 # Save the current value of the expression.
6052 push @old_watch, $val;
6054 # We are now watching expressions.
6063 # Null expression if no arguments.
6064 my $expr = shift || '';
6066 # If expression is not null ...
6067 if ( $expr =~ /\A\S/ ) {
6068 _add_watch_expr($expr);
6069 } ## end if ($expr =~ /^(\S.*)/)
6071 # You have to give one to get one.
6073 print $OUT "Adding a watch-expression requires an expression\n"; # hint
6079 =head3 C<cmd_W> - delete watch expressions (command)
6081 This command accepts either a watch expression to be removed from the list
6082 of watch expressions, or C<*> to delete them all.
6084 If C<*> is specified, we simply empty the watch expression list and the
6085 watch expression value list. We also turn off the bit that says we've got
6088 If an expression (or partial expression) is specified, we pattern-match
6089 through the expressions and remove the ones that match. We also discard
6090 the corresponding values. If no watch expressions are left, we turn off
6091 the I<watching expressions> bit.
6097 my $expr = shift || '';
6100 if ( $expr eq '*' ) {
6105 print $OUT "Deleting all watch expressions ...\n";
6108 @to_watch = @old_watch = ();
6111 # Delete one of them.
6112 elsif ( $expr =~ /^(\S.*)/ ) {
6114 # Where we are in the list.
6117 # For each expression ...
6118 foreach (@to_watch) {
6119 my $val = $to_watch[$i_cnt];
6121 # Does this one match the command argument?
6122 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
6123 # Yes. Turn it off, and its value too.
6124 splice( @to_watch, $i_cnt, 1 );
6125 splice( @old_watch, $i_cnt, 1 );
6128 } ## end foreach (@to_watch)
6130 # We don't bother to turn watching off because
6131 # a) we don't want to stop calling watchfunction() if it exists
6132 # b) foreach over a null list doesn't do anything anyway
6134 } ## end elsif ($expr =~ /^(\S.*)/)
6136 # No command arguments entered.
6139 "Deleting a watch-expression requires an expression, or '*' for all\n"
6144 ### END of the API section
6146 =head1 SUPPORT ROUTINES
6148 These are general support routines that are used in a number of places
6149 throughout the debugger.
6153 save() saves the user's versions of globals that would mess us up in C<@saved>,
6154 and installs the versions we like better.
6160 # Save eval failure, command failure, extended OS error, output field
6161 # separator, input record separator, output record separator and
6162 # the warning setting.
6163 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
6165 $, = ""; # output field separator is null string
6166 $/ = "\n"; # input record separator is newline
6167 $\ = ""; # output record separator is null string
6168 $^W = 0; # warnings are off
6171 =head2 C<print_lineinfo> - show where we are now
6173 print_lineinfo prints whatever it is that it is handed; it prints it to the
6174 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
6175 us to feed line information to a slave editor without messing up the
6180 sub print_lineinfo {
6182 # Make the terminal sensible if we're not the primary debugger.
6183 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
6186 # $LINEINFO may be undef if $noTTY is set or some other issue.
6189 print {$LINEINFO} @_;
6191 } ## end sub print_lineinfo
6193 =head2 C<postponed_sub>
6195 Handles setting postponed breakpoints in subroutines once they're compiled.
6196 For breakpoints, we use C<DB::find_sub> to locate the source file and line
6197 range for the subroutine, then mark the file as having a breakpoint,
6198 temporarily switch the C<*dbline> glob over to the source file, and then
6199 search the given range of lines to find a breakable line. If we find one,
6200 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
6204 # The following takes its argument via $evalarg to preserve current @_
6208 # Get the subroutine name.
6209 my $subname = shift;
6211 # If this is a 'break +<n> if <condition>' ...
6212 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
6214 # If there's no offset, use '+0'.
6215 my $offset = $1 || 0;
6217 # find_sub's value is 'fullpath-filename:start-stop'. It's
6218 # possible that the filename might have colons in it too.
6219 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
6222 # We got the start line. Add the offset '+<n>' from
6223 # $postponed{subname}.
6226 # Switch to the file this sub is in, temporarily.
6227 local *dbline = $main::{ '_<' . $file };
6229 # No warnings, please.
6230 local $^W = 0; # != 0 is magical below
6232 # This file's got a breakpoint in it.
6233 $had_breakpoints{$file} |= 1;
6235 # Last line in file.
6238 # Search forward until we hit a breakable line or get to
6239 # the end of the file.
6240 ++$i until $dbline[$i] != 0 or $i >= $max;
6242 # Copy the breakpoint in and delete it from %postponed.
6243 $dbline{$i} = delete $postponed{$subname};
6246 # find_sub didn't find the sub.
6249 print $OUT "Subroutine $subname not found.\n";
6252 } ## end if ($postponed{$subname...
6253 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
6255 #print $OUT "In postponed_sub for '$subname'.\n";
6256 } ## end sub postponed_sub
6260 Called after each required file is compiled, but before it is executed;
6261 also called if the name of a just-compiled subroutine is a key of
6262 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
6263 etc.) into the just-compiled code.
6265 If this is a C<require>'d file, the incoming parameter is the glob
6266 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
6268 If it's a subroutine, the incoming parameter is the subroutine name.
6274 # If there's a break, process it.
6275 if ($ImmediateStop) {
6277 # Right, we've stopped. Turn it off.
6280 # Enter the command loop when DB::DB gets called.
6284 # If this is a subroutine, let postponed_sub() deal with it.
6285 if (ref(\$_[0]) ne 'GLOB') {
6286 return postponed_sub(@_);
6289 # Not a subroutine. Deal with the file.
6290 local *dbline = shift;
6291 my $filename = $dbline;
6292 $filename =~ s/^_<//;
6294 $signal = 1, print $OUT "'$filename' loaded...\n"
6295 if $break_on_load{$filename};
6296 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
6298 # Do we have any breakpoints to put in this file?
6299 return unless $postponed_file{$filename};
6301 # Yes. Mark this file as having breakpoints.
6302 $had_breakpoints{$filename} |= 1;
6304 # "Cannot be done: insufficient magic" - we can't just put the
6305 # breakpoints saved in %postponed_file into %dbline by assigning
6306 # the whole hash; we have to do it one item at a time for the
6307 # breakpoints to be set properly.
6308 #%dbline = %{$postponed_file{$filename}};
6310 # Set the breakpoints, one at a time.
6313 for $key ( keys %{ $postponed_file{$filename} } ) {
6315 # Stash the saved breakpoint into the current file's magic line array.
6316 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
6319 # This file's been compiled; discard the stored breakpoints.
6320 delete $postponed_file{$filename};
6322 } ## end sub postponed
6326 C<dumpit> is the debugger's wrapper around dumpvar.pl.
6328 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
6329 a reference to a variable (the thing to be dumped) as its input.
6331 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
6332 the currently-selected filehandle, thank you very much). The current
6333 values of the package globals C<$single> and C<$trace> are backed up in
6334 lexicals, and they are turned off (this keeps the debugger from trying
6335 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
6336 preserve its current value and it is set to zero to prevent entry/exit
6337 messages from printing, and C<$doret> is localized as well and set to -2 to
6338 prevent return values from being shown.
6340 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
6341 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
6342 installed version in C<@INC>, yours will be used instead. Possible security
6345 It then checks to see if the subroutine C<main::dumpValue> is now defined
6346 it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
6347 localizes the globals necessary for things to be sane when C<main::dumpValue()>
6348 is called, and picks up the variable to be dumped from the parameter list.
6350 It checks the package global C<%options> to see if there's a C<dumpDepth>
6351 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
6352 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
6353 structure: -1 means dump everything.
6355 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
6358 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
6359 and we then return to the caller.
6365 # Save the current output filehandle and switch to the one
6366 # passed in as the first parameter.
6367 my $savout = select(shift);
6369 # Save current settings of $single and $trace, and then turn them off.
6370 my $osingle = $single;
6371 my $otrace = $trace;
6372 $single = $trace = 0;
6374 # XXX Okay, what do $frame and $doret do, again?
6378 # Load dumpvar.pl unless we've already got the sub we need from it.
6379 unless ( defined &main::dumpValue ) {
6380 do 'dumpvar.pl' or die $@;
6383 # If the load succeeded (or we already had dumpvalue()), go ahead
6385 if ( defined &main::dumpValue ) {
6390 my $maxdepth = shift || $option{dumpDepth};
6391 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
6392 main::dumpValue( $v, $maxdepth );
6393 } ## end if (defined &main::dumpValue)
6395 # Oops, couldn't load dumpvar.pl.
6398 print $OUT "dumpvar.pl not available.\n";
6401 # Reset $single and $trace to their old values.
6405 # Restore the old filehandle.
6409 =head2 C<print_trace>
6411 C<print_trace>'s job is to print a stack trace. It does this via the
6412 C<dump_trace> routine, which actually does all the ferreting-out of the
6413 stack trace data. C<print_trace> takes care of formatting it nicely and
6414 printing it to the proper filehandle.
6422 The filehandle to print to.
6426 How many frames to skip before starting trace.
6430 How many frames to print.
6434 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
6438 The original comment below seems to be noting that the traceback may not be
6439 correct if this routine is called in a tied method.
6443 # Tied method do not create a context, so may get wrong message:
6449 # If this is going to a slave editor, but we're not the primary
6450 # debugger, reset it first.
6452 if $fh eq $LINEINFO # slave editor
6453 and $LINEINFO eq $OUT # normal output
6454 and $term_pid != $$; # not the primary
6456 # Collect the actual trace information to be formatted.
6457 # This is an array of hashes of subroutine call info.
6458 my @sub = dump_trace( $_[0] + 1, $_[1] );
6460 # Grab the "short report" flag from @_.
6461 my $short = $_[2]; # Print short report, next one for sub name
6463 # Run through the traceback info, format it, and print it.
6465 for my $i (0 .. $#sub) {
6467 # Drop out if the user has lost interest and hit control-C.
6470 # Set the separator so arrays print nice.
6473 # Grab and stringify the arguments if they are there.
6475 defined $sub[$i]{args}
6476 ? "(@{ $sub[$i]{args} })"
6479 # Shorten them up if $maxtrace says they're too long.
6480 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
6481 if length $args > $maxtrace;
6483 # Get the file name.
6484 my $file = $sub[$i]{file};
6486 # Put in a filename header if short is off.
6487 $file = $file eq '-e' ? $file : "file '$file'" unless $short;
6489 # Get the actual sub's name, and shorten to $maxtrace's requirement.
6490 $s = $sub[$i]{'sub'};
6491 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
6493 # Short report uses trimmed file and sub names.
6495 my $sub = @_ >= 4 ? $_[3] : $s;
6496 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
6497 } ## end if ($short)
6499 # Non-short report includes full names.
6501 print $fh "$sub[$i]{context} = $s$args"
6502 . " called from $file"
6503 . " line $sub[$i]{line}\n";
6505 } ## end for my $i (0 .. $#sub)
6506 } ## end sub print_trace
6508 =head2 dump_trace(skip[,count])
6510 Actually collect the traceback information available via C<caller()>. It does
6511 some filtering and cleanup of the data, but mostly it just collects it to
6512 make C<print_trace()>'s job easier.
6514 C<skip> defines the number of stack frames to be skipped, working backwards
6515 from the most current. C<count> determines the total number of frames to
6516 be returned; all of them (well, the first 10^9) are returned if C<count>
6519 This routine returns a list of hashes, from most-recent to least-recent
6520 stack frame. Each has the following keys and values:
6524 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
6526 =item * C<sub> - subroutine name, or C<eval> information
6528 =item * C<args> - undef, or a reference to an array of arguments
6530 =item * C<file> - the file in which this item was defined (if any)
6532 =item * C<line> - the line on which it was defined
6538 sub _dump_trace_calc_saved_single_arg
6540 my ($nothard, $arg) = @_;
6543 if ( not defined $arg ) { # undefined parameter
6547 elsif ( $nothard and tied $arg ) { # tied parameter
6550 elsif ( $nothard and $type = ref $arg ) { # reference
6551 return "ref($type)";
6553 else { # can be stringified
6555 "$arg"; # Safe to stringify now - should not call f().
6557 # Backslash any single-quotes or backslashes.
6560 # Single-quote it unless it's a number or a colon-separated
6563 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
6565 # Turn high-bit characters into meta-whatever, and controls into like
6567 require 'meta_notation.pm';
6568 $_ = _meta_notation($_) if /[[:^print:]]/a;
6574 sub _dump_trace_calc_save_args {
6578 map { _dump_trace_calc_saved_single_arg($nothard, $_) } @args
6584 # How many levels to skip.
6587 # How many levels to show. (1e9 is a cheap way of saying "all of them";
6588 # it's unlikely that we'll have more than a billion stack frames. If you
6589 # do, you've got an awfully big machine...)
6590 my $count = shift || 1e9;
6592 # We increment skip because caller(1) is the first level *back* from
6593 # the current one. Add $skip to the count of frames so we have a
6594 # simple stop criterion, counting from $skip to $count+$skip.
6598 # These variables are used to capture output from caller();
6599 my ( $p, $file, $line, $sub, $h, $context );
6601 my ( $e, $r, @sub, $args );
6603 # XXX Okay... why'd we do that?
6604 my $nothard = not $frame & 8;
6607 # Do not want to trace this.
6608 my $otrace = $trace;
6611 # Start out at the skip count.
6612 # If we haven't reached the number of frames requested, and caller() is
6613 # still returning something, stay in the loop. (If we pass the requested
6614 # number of stack frames, or we run out - caller() returns nothing - we
6616 # Up the stack frame index to go back one more level each time.
6620 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
6625 # Go through the arguments and save them for later.
6626 my $save_args = _dump_trace_calc_save_args($nothard);
6628 # If context is true, this is array (@)context.
6629 # If context is false, this is scalar ($) context.
6630 # If neither, context isn't defined. (This is apparently a 'can't
6632 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
6634 # if the sub has args ($h true), make an anonymous array of the
6636 $args = $h ? $save_args : undef;
6638 # remove trailing newline-whitespace-semicolon-end of line sequence
6639 # from the eval text, if any.
6640 $e =~ s/\n\s*\;\s*\Z// if $e;
6642 # Escape backslashed single-quotes again if necessary.
6643 $e =~ s/([\\\'])/\\$1/g if $e;
6645 # if the require flag is true, the eval text is from a require.
6647 $sub = "require '$e'";
6650 # if it's false, the eval text is really from an eval.
6651 elsif ( defined $r ) {
6655 # If the sub is '(eval)', this is a block eval, meaning we don't
6656 # know what the eval'ed text actually was.
6657 elsif ( $sub eq '(eval)' ) {
6658 $sub = "eval {...}";
6661 # Stick the collected information into @sub as an anonymous hash.
6665 context => $context,
6673 # Stop processing frames if the user hit control-C.
6675 } ## end for ($i = $skip ; $i < ...
6677 # Restore the trace value again.
6680 } ## end sub dump_trace
6684 C<action()> takes input provided as the argument to an add-action command,
6685 either pre- or post-, and makes sure it's a complete command. It doesn't do
6686 any fancy parsing; it just keeps reading input until it gets a string
6687 without a trailing backslash.
6694 while ( $action =~ s/\\$// ) {
6696 # We have a backslash on the end. Read more.
6698 } ## end while ($action =~ s/\\$//)
6700 # Return the assembled action.
6706 This routine mostly just packages up a regular expression to be used
6707 to check that the thing it's being matched against has properly-matched
6710 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
6711 speeds things up by only creating the qr//'ed expression once; if it's
6712 already defined, we don't try to define it again. A speed hack.
6716 use vars qw($balanced_brace_re);
6720 # I hate using globals!
6721 $balanced_brace_re ||= qr{
6724 (?> [^{}] + ) # Non-parens without backtracking
6726 (??{ $balanced_brace_re }) # Group with matching parens
6730 return $_[0] !~ m/$balanced_brace_re/;
6731 } ## end sub unbalanced
6735 C<gets()> is a primitive (very primitive) routine to read continuations.
6736 It was devised for reading continuations for actions.
6737 it just reads more input with C<readline()> and returns it.
6742 return DB::readline("cont: ");
6745 =head2 C<_db_system()> - handle calls to<system()> without messing up the debugger
6747 The C<system()> function assumes that it can just go ahead and use STDIN and
6748 STDOUT, but under the debugger, we want it to use the debugger's input and
6751 C<_db_system()> socks away the program's STDIN and STDOUT, and then substitutes
6752 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
6753 and then puts everything back again.
6759 # We save, change, then restore STDIN and STDOUT to avoid fork() since
6760 # some non-Unix systems can do system() but have problems with fork().
6761 open( SAVEIN, "<&STDIN" ) || _db_warn("Can't save STDIN");
6762 open( SAVEOUT, ">&STDOUT" ) || _db_warn("Can't save STDOUT");
6763 open( STDIN, "<&IN" ) || _db_warn("Can't redirect STDIN");
6764 open( STDOUT, ">&OUT" ) || _db_warn("Can't redirect STDOUT");
6766 # XXX: using csh or tcsh destroys sigint retvals!
6768 open( STDIN, "<&SAVEIN" ) || _db_warn("Can't restore STDIN");
6769 open( STDOUT, ">&SAVEOUT" ) || _db_warn("Can't restore STDOUT");
6773 # most of the $? crud was coping with broken cshisms
6775 _db_warn( "(Command exited ", ( $? >> 8 ), ")\n" );
6779 "(Command died of SIG#",
6781 ( ( $? & 128 ) ? " -- core dumped" : "" ),
6790 *system = \&_db_system;
6792 =head1 TTY MANAGEMENT
6794 The subs here do some of the terminal management for multiple debuggers.
6798 Top-level function called when we want to set up a new terminal for use
6801 If the C<noTTY> debugger option was set, we'll either use the terminal
6802 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
6803 to find one. If we're a forked debugger, we call C<resetterm> to try to
6804 get a whole new terminal if we can.
6806 In either case, we set up the terminal next. If the C<ReadLine> option was
6807 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6808 the appropriate attributes. We then
6812 use vars qw($ornaments);
6813 use vars qw($rl_attribs);
6817 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6820 require Term::ReadLine;
6822 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6825 my ( $i, $o ) = split $tty, /,/;
6826 $o = $i unless defined $o;
6827 open( IN, "<$i" ) or die "Cannot open TTY '$i' for read: $!";
6828 open( OUT, ">$o" ) or die "Cannot open TTY '$o' for write: $!";
6834 # We don't have a TTY - try to find one via Term::Rendezvous.
6836 require Term::Rendezvous;
6838 # See if we have anything to pass to Term::Rendezvous.
6839 # Use $HOME/.perldbtty$$ if not.
6840 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6842 # Rendezvous and get the filehandles.
6843 my $term_rv = Term::Rendezvous->new( $rv );
6845 $OUT = $term_rv->OUT;
6846 } ## end else [ if ($tty)
6847 } ## end if ($notty)
6849 # We're a daughter debugger. Try to fork off another TTY.
6850 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6854 # If we shouldn't use Term::ReadLine, don't.
6856 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6859 # We're using Term::ReadLine. Get all the attributes for this terminal.
6861 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6863 $rl_attribs = $term->Attribs;
6864 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6865 if defined $rl_attribs->{basic_word_break_characters}
6866 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6867 $rl_attribs->{special_prefixes} = '$@&%';
6868 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6869 $rl_attribs->{completion_function} = \&db_complete;
6870 } ## end else [ if (!$rl)
6872 # Set up the LINEINFO filehandle.
6873 $LINEINFO = $OUT unless defined $LINEINFO;
6874 $lineinfo = $console unless defined $lineinfo;
6880 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6881 $term->SetHistory(@hist);
6884 # XXX Ornaments are turned on unconditionally, which is not
6885 # always a good thing.
6886 ornaments($ornaments) if defined $ornaments;
6888 } ## end sub setterm
6891 $histfile //= option_val("HistFile", undef);
6892 return unless defined $histfile;
6893 open my $fh, "<", $histfile or return;
6904 return unless defined $histfile;
6905 eval { require File::Path } or return;
6906 eval { require File::Basename } or return;
6907 File::Path::mkpath(File::Basename::dirname($histfile));
6908 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6909 $histsize //= option_val("HistSize",100);
6910 my @copy = grep { $_ ne '?' } @hist;
6911 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6912 for ($start .. $#copy) {
6913 print $fh "$copy[$_]\n";
6915 close $fh or die "Could not write '$histfile': $!";
6918 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6920 When the process being debugged forks, or the process invokes a command
6921 via C<system()> which starts a new debugger, we need to be able to get a new
6922 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6923 fight over the terminal, and you can never quite be sure who's going to get the
6924 input you're typing.
6926 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6927 is tasked with doing all the necessary operating system mojo to get a new
6928 TTY (and probably another window) and to direct the new debugger to read and
6931 The debugger provides C<get_fork_TTY> functions which work for TCP
6932 socket servers, X11, OS/2, and Mac OS X. Other systems are not
6933 supported. You are encouraged to write C<get_fork_TTY> functions which
6934 work for I<your> platform and contribute them.
6936 =head3 C<socket_get_fork_TTY>
6940 sub connect_remoteport {
6943 my $socket = IO::Socket::INET->new(
6945 PeerAddr => $remoteport,
6949 die "Unable to connect to remote host: $remoteport\n";
6954 sub socket_get_fork_TTY {
6955 $tty = $LINEINFO = $IN = $OUT = connect_remoteport();
6957 # Do I need to worry about setting $term?
6959 reset_IN_OUT( $IN, $OUT );
6963 =head3 C<xterm_get_fork_TTY>
6965 This function provides the C<get_fork_TTY> function for X11. If a
6966 program running under the debugger forks, a new <xterm> window is opened and
6967 the subsidiary debugger is directed there.
6969 The C<open()> call is of particular note here. We have the new C<xterm>
6970 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6971 command (which prints the device name of the TTY we'll want to use for input
6972 and output to STDOUT, then C<sleep> for a very long time, routing this output
6973 to file number 3. This way we can simply read from the <XT> filehandle (which
6974 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6976 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6981 sub xterm_get_fork_TTY {
6982 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6984 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6987 # Get the output from 'tty' and clean it up a little.
6991 $pidprompt = ''; # Shown anyway in titlebar
6993 # We need $term defined or we can not switch to the newly created xterm
6994 if ($tty ne '' && !defined $term) {
6995 require Term::ReadLine;
6997 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
7000 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
7003 # There's our new TTY.
7005 } ## end sub xterm_get_fork_TTY
7007 =head3 C<os2_get_fork_TTY>
7009 XXX It behooves an OS/2 expert to write the necessary documentation for this!
7013 # This example function resets $IN, $OUT itself
7015 sub os2_get_fork_TTY { # A simplification of the following (and works without):
7017 ( my $name = $0 ) =~ s,^.*[/\\],,s;
7018 my %opt = ( title => "Daughter Perl debugger $pids $name",
7019 ($rl ? (read_by_key => 1) : ()) );
7020 require OS2::Process;
7021 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
7023 $pidprompt = ''; # Shown anyway in titlebar
7024 reset_IN_OUT($in, $out);
7026 return ''; # Indicate that reset_IN_OUT is called
7027 } ## end sub os2_get_fork_TTY
7029 =head3 C<macosx_get_fork_TTY>
7031 The Mac OS X version uses AppleScript to tell Terminal.app to create
7036 # Notes about Terminal.app's AppleScript support,
7037 # (aka things that might break in future OS versions).
7039 # The "do script" command doesn't return a reference to the new window
7040 # it creates, but since it appears frontmost and windows are enumerated
7041 # front to back, we can use "first window" === "window 1".
7043 # Since "do script" is implemented by supplying the argument (plus a
7044 # return character) as terminal input, there's a potential race condition
7045 # where the debugger could beat the shell to reading the command.
7046 # To prevent this, we wait for the screen to clear before proceeding.
7049 # There's no direct accessor for the tty device name, so we fiddle
7050 # with the window title options until it says what we want.
7053 # There _is_ a direct accessor for the tty device name, _and_ there's
7054 # a new possible component of the window title (the name of the settings
7055 # set). A separate version is needed.
7057 my @script_versions=
7059 ([237, <<'__LEOPARD__'],
7060 tell application "Terminal"
7061 do script "clear;exec sleep 100000"
7062 tell first tab of first window
7064 set custom title to "forked perl debugger"
7065 set title displays custom title to true
7066 repeat while (length of first paragraph of (get contents)) > 0
7074 [100, <<'__JAGUAR_TIGER__'],
7075 tell application "Terminal"
7076 do script "clear;exec sleep 100000"
7078 set title displays shell path to false
7079 set title displays window size to false
7080 set title displays file name to false
7081 set title displays device name to true
7082 set title displays custom title to true
7083 set custom title to ""
7084 copy "/dev/" & name to thetty
7085 set custom title to "forked perl debugger"
7086 repeat while (length of first paragraph of (get contents)) > 0
7096 sub macosx_get_fork_TTY
7098 my($version,$script,$pipe,$tty);
7100 return unless $version=$ENV{TERM_PROGRAM_VERSION};
7101 foreach my $entry (@script_versions) {
7102 if ($version>=$entry->[0]) {
7103 $script=$entry->[1];
7107 return unless defined($script);
7108 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script);
7109 $tty=readline($pipe);
7111 return unless defined($tty) && $tty =~ m(^/dev/);
7116 =head3 C<tmux_get_fork_TTY>
7118 Creates a split window for subprocesses when a process running under the
7119 perl debugger in Tmux forks.
7123 sub tmux_get_fork_TTY {
7124 return unless $ENV{TMUX};
7128 my $status = open $pipe, '-|', 'tmux', 'split-window',
7129 '-P', '-F', '#{pane_tty}', 'sleep 100000';
7141 if ( !defined $term ) {
7142 require Term::ReadLine;
7144 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
7147 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
7155 =head2 C<create_IN_OUT($flags)>
7157 Create a new pair of filehandles, pointing to a new TTY. If impossible,
7158 try to diagnose why.
7164 =item * 1 - Don't know how to create a new TTY.
7166 =item * 2 - Debugger has forked, but we can't get a new TTY.
7168 =item * 4 - standard debugger startup is happening.
7174 use vars qw($fork_TTY);
7176 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
7178 # If we know how to get a new TTY, do it! $in will have
7179 # the TTY name if get_fork_TTY works.
7180 my $in = get_fork_TTY(@_) if defined &get_fork_TTY;
7182 # It used to be that
7183 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
7185 if ( not defined $in ) {
7188 # We don't know how.
7189 print_help(<<EOP) if $why == 1;
7190 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
7194 print_help(<<EOP) if $why == 2;
7195 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
7196 This may be an asynchronous session, so the parent debugger may be active.
7199 # Note that both debuggers are fighting over the same input.
7200 print_help(<<EOP) if $why != 4;
7201 Since two debuggers fight for the same TTY, input is severely entangled.
7205 I know how to switch the output to a different window in xterms, OS/2
7206 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
7207 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
7208 B<DB::get_fork_TTY()> returning this.
7210 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
7211 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
7214 } ## end if (not defined $in)
7215 elsif ( $in ne '' ) {
7219 $console = ''; # Indicate no need to open-from-the-console
7222 } ## end sub create_IN_OUT
7226 Handles rejiggering the prompt when we've forked off a new debugger.
7228 If the new debugger happened because of a C<system()> that invoked a
7229 program under the debugger, the arrow between the old pid and the new
7230 in the prompt has I<two> dashes instead of one.
7232 We take the current list of pids and add this one to the end. If there
7233 isn't any list yet, we make one up out of the initial pid associated with
7234 the terminal and our new pid, sticking an arrow (either one-dashed or
7235 two dashed) in between them.
7237 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
7238 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
7243 sub resetterm { # We forked, so we need a different TTY
7245 # Needs to be passed to create_IN_OUT() as well.
7248 # resetterm(2): got in here because of a system() starting a debugger.
7249 # resetterm(1): just forked.
7250 my $systemed = $in > 1 ? '-' : '';
7252 # If there's already a list of pids, add this to the end.
7254 $pids =~ s/\]/$systemed->$$]/;
7257 # No pid list. Time to make one.
7259 $pids = "[$term_pid->$$]";
7262 # The prompt we're going to be using for this debugger.
7265 # We now 0wnz this terminal.
7268 # Just return if we're not supposed to try to create a new TTY.
7269 return unless $CreateTTY & $in;
7271 # Try to create a new IN/OUT pair.
7273 } ## end sub resetterm
7277 First, we handle stuff in the typeahead buffer. If there is any, we shift off
7278 the next line, print a message saying we got it, add it to the terminal
7279 history (if possible), and return it.
7281 If there's nothing in the typeahead buffer, check the command filehandle stack.
7282 If there are any filehandles there, read from the last one, and return the line
7283 if we got one. If not, we pop the filehandle off and close it, and try the
7284 next one up the stack.
7286 If we've emptied the filehandle stack, we check to see if we've got a socket
7287 open, and we read that and return it if we do. If we don't, we just call the
7288 core C<readline()> and return its value.
7294 # Localize to prevent it from being smashed in the program being debugged.
7297 # If there are stacked filehandles to read from ...
7298 # (Handle it before the typeahead, because we may call source/etc. from
7302 # Read from the last one in the stack.
7303 my $line = CORE::readline( $cmdfhs[-1] );
7305 # If we got a line ...
7307 ? ( print $OUT ">> $line" and return $line ) # Echo and return
7308 : close pop @cmdfhs; # Pop and close
7309 } ## end while (@cmdfhs)
7311 # Pull a line out of the typeahead if there's stuff there.
7314 # How many lines left.
7315 my $left = @typeahead;
7317 # Get the next line.
7318 my $got = shift @typeahead;
7320 # Print a message saying we got input from the typeahead.
7322 print $OUT "auto(-$left)", shift, $got, "\n";
7324 # Add it to the terminal history (if possible).
7325 $term->AddHistory($got)
7327 and defined $term->Features->{addHistory};
7329 } ## end if (@typeahead)
7331 # We really need to read some input. Turn off entry/exit trace and
7332 # return value printing.
7336 # Nothing on the filehandle stack. Socket?
7337 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
7339 # Send anything we have to send.
7340 $OUT->write( join( '', @_ ) );
7342 # Receive anything there is to receive.
7347 while ($first_time or (length($buf) && ($stuff .= $buf) !~ /\n/))
7350 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
7351 # XXX Don't know. You tell me.
7356 } ## end if (ref $OUT and UNIVERSAL::isa...
7358 # No socket. Just read from the terminal.
7360 return $term->readline(@_);
7362 } ## end sub readline
7364 =head1 OPTIONS SUPPORT ROUTINES
7366 These routines handle listing and setting option values.
7368 =head2 C<dump_option> - list the current value of an option setting
7370 This routine uses C<option_val> to look up the value for an option.
7371 It cleans up escaped single-quotes and then displays the option and
7377 my ( $opt, $val ) = @_;
7378 $val = option_val( $opt, 'N/A' );
7379 $val =~ s/([\\\'])/\\$1/g;
7380 printf $OUT "%20s = '%s'\n", $opt, $val;
7381 } ## end sub dump_option
7383 sub options2remember {
7384 foreach my $k (@RememberOnROptions) {
7385 $option{$k} = option_val( $k, 'N/A' );
7390 =head2 C<option_val> - find the current value of an option
7392 This can't just be a simple hash lookup because of the indirect way that
7393 the option values are stored. Some are retrieved by calling a subroutine,
7394 some are just variables.
7396 You must supply a default value to be used in case the option isn't set.
7401 my ( $opt, $default ) = @_;
7404 # Does this option exist, and is it a variable?
7405 # If so, retrieve the value via the value in %optionVars.
7406 if ( defined $optionVars{$opt}
7407 and defined ${ $optionVars{$opt} } )
7409 $val = ${ $optionVars{$opt} };
7412 # Does this option exist, and it's a subroutine?
7413 # If so, call the subroutine via the ref in %optionAction
7414 # and capture the value.
7415 elsif ( defined $optionAction{$opt}
7416 and defined &{ $optionAction{$opt} } )
7418 $val = &{ $optionAction{$opt} }();
7421 # If there's an action or variable for the supplied option,
7422 # but no value was set, use the default.
7423 elsif (defined $optionAction{$opt} and not defined $option{$opt}
7424 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
7429 # Otherwise, do the simple hash lookup.
7431 $val = $option{$opt};
7434 # If the value isn't defined, use the default.
7435 # Then return whatever the value is.
7436 $val = $default unless defined $val;
7438 } ## end sub option_val
7440 =head2 C<parse_options>
7442 Handles the parsing and execution of option setting/displaying commands.
7444 An option entered by itself is assumed to be I<set me to 1> (the default value)
7445 if the option is a boolean one. If not, the user is prompted to enter a valid
7446 value or to query the current value (via C<option? >).
7448 If C<option=value> is entered, we try to extract a quoted string from the
7449 value (if it is quoted). If it's not, we just use the whole value as-is.
7451 We load any modules required to service this option, and then we set it: if
7452 it just gets stuck in a variable, we do that; if there's a subroutine to
7453 handle setting the option, we call that.
7455 Finally, if we're running in interactive mode, we display the effect of the
7456 user's command back to the terminal, skipping this if we're setting things
7457 during initialization.
7467 # These options need a value. Don't allow them to be clobbered by accident.
7468 my %opt_needs_val = map { ( $_ => 1 ) } qw{
7469 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
7470 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
7473 while (length($s)) {
7476 # Clean off excess leading whitespace.
7477 $s =~ s/^\s+// && next;
7479 # Options are always all word characters, followed by a non-word
7481 if ($s !~ s/^(\w+)(\W?)//) {
7482 print {$OUT} "Invalid option '$s'\n";
7485 my ( $opt, $sep ) = ( $1, $2 );
7487 # Make sure that such an option exists.
7488 my $matches = ( grep { /^\Q$opt/ && ( $option = $_ ) } @options )
7489 || ( grep { /^\Q$opt/i && ( $option = $_ ) } @options );
7492 print {$OUT} "Unknown option '$opt'\n";
7496 print {$OUT} "Ambiguous option '$opt'\n";
7501 # '?' as separator means query, but must have whitespace after it.
7502 if ( "?" eq $sep ) {
7504 print {$OUT} "Option query '$opt?' followed by non-space '$s'\n" ;
7509 #&dump_option($opt);
7510 } ## end if ("?" eq $sep)
7512 # Separator is whitespace (or just a carriage return).
7513 # They're going for a default, which we assume is 1.
7514 elsif ( $sep !~ /\S/ ) {
7516 $val = "1"; # this is an evil default; make 'em set it!
7519 # Separator is =. Trying to set a value.
7520 elsif ( $sep eq "=" ) {
7522 # If quoted, extract a quoted string.
7523 if ($s =~ s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
7525 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
7528 # Not quoted. Use the whole thing. Warn about 'option='.
7532 print OUT qq(Option better cleared using $opt=""\n)
7534 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
7536 } ## end elsif ($sep eq "=")
7538 # "Quoted" with [], <>, or {}.
7539 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
7541 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
7542 $s =~ s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
7543 or print( $OUT "Unclosed option value '$opt$sep$_'\n" ), last;
7544 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
7545 } ## end else [ if ("?" eq $sep)
7547 # Exclude non-booleans from getting set to 1 by default.
7548 if ( $opt_needs_val{$option} && $val_defaulted ) {
7549 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
7551 "Option '$opt' is non-boolean. Use '$cmd $option=VAL' to set, '$cmd $option?' to query\n";
7553 } ## end if ($opt_needs_val{$option...
7555 # Save the option value.
7556 $option{$option} = $val if defined $val;
7558 # Load any module that this option requires.
7559 if ( defined($optionRequire{$option}) && defined($val) ) {
7563 require '$optionRequire{$option}';
7565 } || die $@ # XXX: shouldn't happen
7569 # Stick it in the proper variable if it goes in a variable.
7570 if (defined($optionVars{$option}) && defined($val)) {
7571 ${ $optionVars{$option} } = $val;
7574 # Call the appropriate sub if it gets set via sub.
7575 if (defined($optionAction{$option})
7576 && defined (&{ $optionAction{$option} })
7579 &{ $optionAction{$option} }($val);
7582 # Not initialization - echo the value we set it to.
7583 dump_option($option) if ($OUT ne \*STDERR);
7584 } ## end while (length)
7585 } ## end sub parse_options
7587 =head1 RESTART SUPPORT
7589 These routines are used to store (and restore) lists of items in environment
7590 variables during a restart.
7594 Set_list packages up items to be stored in a set of environment variables
7595 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
7596 the values). Values outside the standard ASCII charset are stored by encoding
7597 them as hexadecimal values.
7602 my ( $stem, @list ) = @_;
7605 # VAR_n: how many we have. Scalar assignment gets the number of items.
7606 $ENV{"${stem}_n"} = @list;
7608 # Grab each item in the list, escape the backslashes, encode the non-ASCII
7609 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
7610 for my $i ( 0 .. $#list ) {
7612 $val =~ s/\\/\\\\/g;
7613 no warnings 'experimental::regex_sets';
7614 $val =~ s/ ( (?[ [\000-\xFF] & [:^print:] ]) ) /
7615 "\\0x" . unpack('H2',$1)/xaeg;
7616 $ENV{"${stem}_$i"} = $val;
7617 } ## end for $i (0 .. $#list)
7618 } ## end sub set_list
7622 Reverse the set_list operation: grab VAR_n to see how many we should be getting
7623 back, and then pull VAR_0, VAR_1. etc. back out.
7630 my $n = delete $ENV{"${stem}_n"};
7632 for my $i ( 0 .. $n - 1 ) {
7633 $val = delete $ENV{"${stem}_$i"};
7634 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
7638 } ## end sub get_list
7640 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
7644 The C<catch()> subroutine is the essence of fast and low-impact. We simply
7645 set an already-existing global scalar variable to a constant value. This
7646 avoids allocating any memory possibly in the middle of something that will
7647 get all confused if we do, particularly under I<unsafe signals>.
7653 return; # Put nothing on the stack - malloc/free land!
7658 C<warn> emits a warning, by joining together its arguments and printing
7659 them, with couple of fillips.
7661 If the composited message I<doesn't> end with a newline, we automatically
7662 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
7663 to be set to the filehandle to be used to output warnings; it makes no
7664 assumptions about what filehandles are available.
7669 my ($msg) = join( "", @_ );
7670 $msg .= ": $!\n" unless $msg =~ /\n$/;
7677 =head1 INITIALIZATION TTY SUPPORT
7679 =head2 C<reset_IN_OUT>
7681 This routine handles restoring the debugger's input and output filehandles
7682 after we've tried and failed to move them elsewhere. In addition, it assigns
7683 the debugger's output filehandle to $LINEINFO if it was already open there.
7688 my $switch_li = $LINEINFO eq $OUT;
7690 # If there's a term and it's able to get a new tty, try to get one.
7691 if ( $term and $term->Features->{newTTY} ) {
7692 ( $IN, $OUT ) = ( shift, shift );
7693 $term->newTTY( $IN, $OUT );
7696 # This term can't get a new tty now. Better luck later.
7698 _db_warn("Too late to set IN/OUT filehandles, enabled on next 'R'!\n");
7701 # Set the filehndles up as they were.
7703 ( $IN, $OUT ) = ( shift, shift );
7706 # Unbuffer the output filehandle.
7709 # Point LINEINFO to the same output filehandle if it was there before.
7710 $LINEINFO = $OUT if $switch_li;
7711 } ## end sub reset_IN_OUT
7713 =head1 OPTION SUPPORT ROUTINES
7715 The following routines are used to process some of the more complicated
7720 Sets the input and output filehandles to the specified files or pipes.
7721 If the terminal supports switching, we go ahead and do it. If not, and
7722 there's already a terminal in place, we save the information to take effect
7725 If there's no terminal yet (for instance, during debugger initialization),
7726 we go ahead and set C<$console> and C<$tty> to the file indicated.
7732 if ( @_ and $term and $term->Features->{newTTY} ) {
7734 # This terminal supports switching to a new TTY.
7735 # Can be a list of two files, or on string containing both names,
7737 # XXX Should this perhaps be an assignment from @_?
7738 my ( $in, $out ) = shift;
7741 # Split list apart if supplied.
7742 ( $in, $out ) = split /,/, $in, 2;
7746 # Use the same file for both input and output.
7750 # Open file onto the debugger's filehandles, if you can.
7751 open IN, $in or die "cannot open '$in' for read: $!";
7752 open OUT, ">$out" or die "cannot open '$out' for write: $!";
7754 # Swap to the new filehandles.
7755 reset_IN_OUT( \*IN, \*OUT );
7757 # Save the setting for later.
7759 } ## end if (@_ and $term and $term...
7761 # Terminal doesn't support new TTY, or doesn't support readline.
7762 # Can't do it now, try restarting.
7764 _db_warn("Too late to set TTY, enabled on next 'R'!\n");
7767 # Useful if done through PERLDB_OPTS:
7768 $console = $tty = shift if @_;
7770 # Return whatever the TTY is.
7776 Sets the C<$notty> global, controlling whether or not the debugger tries to
7777 get a terminal to read from. If called after a terminal is already in place,
7778 we save the value to use it if we're restarted.
7784 _db_warn("Too late to set noTTY, enabled on next 'R'!\n") if @_;
7786 $notty = shift if @_;
7792 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
7793 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
7794 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
7795 the value in case a restart is done so we can change it then.
7801 _db_warn("Too late to set ReadLine, enabled on next 'R'!\n") if @_;
7805 } ## end sub ReadLine
7807 =head2 C<RemotePort>
7809 Sets the port that the debugger will try to connect to when starting up.
7810 If the terminal's already been set up, we can't do it, but we remember the
7811 setting in case the user does a restart.
7817 _db_warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
7819 $remoteport = shift if @_;
7821 } ## end sub RemotePort
7825 Checks with the terminal to see if C<Tk> is running, and returns true or
7826 false. Returns false if the current terminal doesn't support C<readline>.
7831 if ( ${ $term->Features }{tkRunning} ) {
7832 return $term->tkRunning(@_);
7836 print $OUT "tkRunning not supported by current ReadLine package.\n";
7839 } ## end sub tkRunning
7843 Sets nonstop mode. If a terminal's already been set up, it's too late; the
7844 debugger remembers the setting in case you restart, though.
7850 _db_warn("Too late to set up NonStop mode, enabled on next 'R'!\n")
7853 $runnonstop = shift if @_;
7855 } ## end sub NonStop
7859 _db_warn("Some flag changes could not take effect until next 'R'!\n")
7862 $^P = parse_DollarCaretP_flags(shift) if @_;
7863 expand_DollarCaretP_flags($^P);
7868 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
7876 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
7883 Sets the shell escape command, and generates a printable copy to be used
7890 # If we got an argument, meta-quote it, and add '\b' if it
7891 # ends in a word character.
7893 $sh = quotemeta shift;
7894 $sh .= "\\b" if $sh =~ /\w$/;
7897 # Generate the printable version for the help:
7898 $psh = $sh; # copy it
7899 $psh =~ s/\\b$//; # Take off trailing \b if any
7900 $psh =~ s/\\(.)/$1/g; # De-escape
7901 $psh; # return the printable version
7902 } ## end sub shellBang
7906 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7907 was passed as the argument. (This means you can't override the terminal's
7913 if ( defined $term ) {
7915 # We don't want to show warning backtraces, but we do want die() ones.
7916 local $warnLevel = 0;
7917 local $dieLevel = 1;
7919 # No ornaments if the terminal doesn't support them.
7920 if (not $term->Features->{ornaments}) {
7924 return (eval { $term->ornaments(@_) } || '');
7927 # Use what was passed in if we can't determine it ourselves.
7934 } ## end sub ornaments
7936 =head2 C<recallCommand>
7938 Sets the recall command, and builds a printable version which will appear in
7945 # If there is input, metaquote it. Add '\b' if it ends with a word
7948 $rc = quotemeta shift;
7949 $rc .= "\\b" if $rc =~ /\w$/;
7952 # Build it into a printable version.
7953 $prc = $rc; # Copy it
7954 $prc =~ s/\\b$//; # Remove trailing \b
7955 $prc =~ s/\\(.)/$1/g; # Remove escapes
7956 return $prc; # Return the printable version
7957 } ## end sub recallCommand
7959 =head2 C<LineInfo> - where the line number information goes
7961 Called with no arguments, returns the file or pipe that line info should go to.
7963 Called with an argument (a file or a pipe), it opens that onto the
7964 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7965 file or pipe again to the caller.
7973 # If this is a valid "thing to be opened for output", tack a
7974 # '>' onto the front.
7975 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7977 # If this is a pipe, the stream points to a slave editor.
7978 $slave_editor = ( $stream =~ /^\|/ );
7980 my $new_lineinfo_fh;
7981 # Open it up and unbuffer it.
7982 open ($new_lineinfo_fh , $stream )
7983 or _db_warn("Cannot open '$stream' for write");
7984 $LINEINFO = $new_lineinfo_fh;
7985 _autoflush($LINEINFO);
7989 } ## end sub LineInfo
7991 =head1 COMMAND SUPPORT ROUTINES
7993 These subroutines provide functionality for various commands.
7995 =head2 C<list_modules>
7997 For the C<M> command: list modules loaded and their versions.
7998 Essentially just runs through the keys in %INC, picks each package's
7999 C<$VERSION> variable, gets the file name, and formats the information
8004 sub list_modules { # versions
8008 # keys are the "as-loaded" name, values are the fully-qualified path
8009 # to the file itself.
8011 $file = $_; # get the module name
8012 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
8013 s,/,::,g; # change '/' to '::'
8014 s/^perl5db$/DB/; # Special case: debugger
8015 # moves to package DB
8016 s/^Term::ReadLine::readline$/readline/; # simplify readline
8018 # If the package has a $VERSION package global (as all good packages
8019 # should!) decode it and save as partial message.
8020 my $pkg_version = do { no strict 'refs'; ${ $_ . '::VERSION' } };
8021 if ( defined $pkg_version ) {
8022 $version{$file} = "$pkg_version from ";
8025 # Finish up the message with the file the package came from.
8026 $version{$file} .= $INC{$file};
8027 } ## end for (keys %INC)
8029 # Hey, dumpit() formats a hash nicely, so why not use it?
8030 dumpit( $OUT, \%version );
8031 } ## end sub list_modules
8035 Sets up the monster string used to format and print the help.
8037 =head3 HELP MESSAGE FORMAT
8039 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
8040 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
8041 easy to parse and portable, but which still allows the help to be a little
8042 nicer than just plain text.
8044 Essentially, you define the command name (usually marked up with C<< B<> >>
8045 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
8046 newline. The descriptive text can also be marked up in the same way. If you
8047 need to continue the descriptive text to another line, start that line with
8048 just tabs and then enter the marked-up text.
8050 If you are modifying the help text, I<be careful>. The help-string parser is
8051 not very sophisticated, and if you don't follow these rules it will mangle the
8052 help beyond hope until you fix the string.
8056 use vars qw($pre580_help);
8057 use vars qw($pre580_summary);
8061 # XXX: make sure there are tabs between the command and explanation,
8062 # or print_help will screw up your formatting if you have
8063 # eeevil ornaments enabled. This is an insane mess.
8066 Help is currently only available for the new 5.8 command set.
8067 No help is available for the old command set.
8068 We assume you know what you're doing if you switch to it.
8071 B<s> [I<expr>] Single step [in I<expr>].
8072 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
8073 <B<CR>> Repeat last B<n> or B<s> command.
8074 B<r> Return from current subroutine.
8075 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
8076 at the specified position.
8077 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
8078 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
8079 B<l> I<line> List single I<line>.
8080 B<l> I<subname> List first window of lines from subroutine.
8081 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
8082 B<l> List next window of lines.
8083 B<-> List previous window of lines.
8084 B<v> [I<line>] View window around I<line>.
8085 B<.> Return to the executed line.
8086 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
8087 I<filename> may be either the full name of the file, or a regular
8088 expression matching the full file name:
8089 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
8090 Evals (with saved bodies) are considered to be filenames:
8091 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
8092 (in the order of execution).
8093 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
8094 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
8095 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
8096 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
8097 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth).
8098 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
8099 B<b> Sets breakpoint on current line)
8100 B<b> [I<line>] [I<condition>]
8101 Set breakpoint; I<line> defaults to the current execution line;
8102 I<condition> breaks if it evaluates to true, defaults to '1'.
8103 B<b> I<subname> [I<condition>]
8104 Set breakpoint at first line of subroutine.
8105 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
8106 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
8107 B<b> B<postpone> I<subname> [I<condition>]
8108 Set breakpoint at first line of subroutine after
8110 B<b> B<compile> I<subname>
8111 Stop after the subroutine is compiled.
8112 B<B> [I<line>] Delete the breakpoint for I<line>.
8113 B<B> I<*> Delete all breakpoints.
8114 B<a> [I<line>] I<command>
8115 Set an action to be done before the I<line> is executed;
8116 I<line> defaults to the current execution line.
8117 Sequence is: check for breakpoint/watchpoint, print line
8118 if necessary, do action, prompt user if necessary,
8121 B<A> [I<line>] Delete the action for I<line>.
8122 B<A> I<*> Delete all actions.
8123 B<w> I<expr> Add a global watch-expression.
8125 B<W> I<expr> Delete a global watch-expression.
8126 B<W> I<*> Delete all watch-expressions.
8127 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
8128 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
8129 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
8130 B<x> I<expr> Evals expression in list context, dumps the result.
8131 B<m> I<expr> Evals expression in list context, prints methods callable
8132 on the first element of the result.
8133 B<m> I<class> Prints methods callable via the given class.
8134 B<M> Show versions of loaded modules.
8135 B<i> I<class> Prints nested parents of given class.
8136 B<e> Display current thread id.
8137 B<E> Display all thread ids the current one will be identified: <n>.
8138 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8140 B<<> ? List Perl commands to run before each prompt.
8141 B<<> I<expr> Define Perl command to run before each prompt.
8142 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
8143 B<< *> Delete the list of perl commands to run before each prompt.
8144 B<>> ? List Perl commands to run after each prompt.
8145 B<>> I<expr> Define Perl command to run after each prompt.
8146 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
8147 B<>>B< *> Delete the list of Perl commands to run after each prompt.
8148 B<{> I<db_command> Define debugger command to run before each prompt.
8149 B<{> ? List debugger commands to run before each prompt.
8150 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
8151 B<{ *> Delete the list of debugger commands to run before each prompt.
8152 B<$prc> I<number> Redo a previous command (default previous command).
8153 B<$prc> I<-number> Redo number'th-to-last command.
8154 B<$prc> I<pattern> Redo last command that started with I<pattern>.
8155 See 'B<O> I<recallCommand>' too.
8156 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
8161 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
8163 See 'B<O> I<shellBang>' too.
8164 B<source> I<file> Execute I<file> containing debugger commands (may nest).
8165 B<save> I<file> Save current debugger session (actual history) to I<file>.
8166 B<rerun> Rerun session to current position.
8167 B<rerun> I<n> Rerun session to numbered command.
8168 B<rerun> I<-n> Rerun session to number'th-to-last command.
8169 B<H> I<-number> Display last number commands (default all).
8170 B<H> I<*> Delete complete history.
8171 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
8172 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
8173 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarily select()ed as well.
8174 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
8175 I<command> Execute as a perl statement in current package.
8176 B<R> Pure-man-restart of debugger, some of debugger state
8177 and command-line options may be lost.
8178 Currently the following settings are preserved:
8179 history, breakpoints and actions, debugger B<O>ptions
8180 and the following command-line options: I<-w>, I<-I>, I<-e>.
8182 B<o> [I<opt>] ... Set boolean option to true
8183 B<o> [I<opt>B<?>] Query options
8184 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
8185 Set options. Use quotes if spaces in value.
8186 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
8187 I<pager> program for output of \"|cmd\";
8188 I<tkRunning> run Tk while prompting (with ReadLine);
8189 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
8190 I<inhibit_exit> Allows stepping off the end of the script.
8191 I<ImmediateStop> Debugger should stop as early as possible.
8192 I<RemotePort> Remote hostname:port for remote debugging
8193 The following options affect what happens with B<V>, B<X>, and B<x> commands:
8194 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
8195 I<compactDump>, I<veryCompact> change style of array and hash dump;
8196 I<globPrint> whether to print contents of globs;
8197 I<DumpDBFiles> dump arrays holding debugged files;
8198 I<DumpPackages> dump symbol tables of packages;
8199 I<DumpReused> dump contents of \"reused\" addresses;
8200 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
8201 I<bareStringify> Do not print the overload-stringified value;
8202 Other options include:
8203 I<PrintRet> affects printing of return value after B<r> command,
8204 I<frame> affects printing messages on subroutine entry/exit.
8205 I<AutoTrace> affects printing messages on possible breaking points.
8206 I<maxTraceLen> gives max length of evals/args listed in stack trace.
8207 I<ornaments> affects screen appearance of the command line.
8208 I<CreateTTY> bits control attempts to create a new TTY on events:
8209 1: on fork() 2: debugger is started inside debugger
8211 During startup options are initialized from \$ENV{PERLDB_OPTS}.
8212 You can put additional initialization options I<TTY>, I<noTTY>,
8213 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
8214 B<R> after you set them).
8216 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
8217 B<h> Summary of debugger commands.
8218 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
8219 B<h h> Long help for debugger commands
8220 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
8221 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
8222 Set B<\$DB::doccmd> to change viewer.
8224 Type '|h h' for a paged display if this was too hard to read.
8226 "; # Fix balance of vi % matching: }}}}
8228 # note: tabs in the following section are not-so-helpful
8229 $summary = <<"END_SUM";
8230 I<List/search source lines:> I<Control script execution:>
8231 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
8232 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
8233 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
8234 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
8235 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
8236 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
8237 I<Debugger controls:> B<L> List break/watch/actions
8238 B<o> [...] Set debugger options B<t> [I<n>] [I<expr>] Toggle trace [max depth] ][trace expr]
8239 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
8240 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
8241 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
8242 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
8243 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
8244 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
8245 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
8246 B<q> or B<^D> Quit B<R> Attempt a restart
8247 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
8248 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
8249 B<p> I<expr> Print expression (uses script's current package).
8250 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
8251 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
8252 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
8253 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8254 B<e> Display thread id B<E> Display all thread ids.
8255 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
8258 # ')}}; # Fix balance of vi % matching
8260 # and this is really numb...
8263 B<s> [I<expr>] Single step [in I<expr>].
8264 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
8265 B<CR>> Repeat last B<n> or B<s> command.
8266 B<r> Return from current subroutine.
8267 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
8268 at the specified position.
8269 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
8270 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
8271 B<l> I<line> List single I<line>.
8272 B<l> I<subname> List first window of lines from subroutine.
8273 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
8274 B<l> List next window of lines.
8275 B<-> List previous window of lines.
8276 B<w> [I<line>] List window around I<line>.
8277 B<.> Return to the executed line.
8278 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
8279 I<filename> may be either the full name of the file, or a regular
8280 expression matching the full file name:
8281 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
8282 Evals (with saved bodies) are considered to be filenames:
8283 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
8284 (in the order of execution).
8285 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
8286 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
8287 B<L> List all breakpoints and actions.
8288 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
8289 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth) .
8290 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
8291 B<b> [I<line>] [I<condition>]
8292 Set breakpoint; I<line> defaults to the current execution line;
8293 I<condition> breaks if it evaluates to true, defaults to '1'.
8294 B<b> I<subname> [I<condition>]
8295 Set breakpoint at first line of subroutine.
8296 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
8297 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
8298 B<b> B<postpone> I<subname> [I<condition>]
8299 Set breakpoint at first line of subroutine after
8301 B<b> B<compile> I<subname>
8302 Stop after the subroutine is compiled.
8303 B<d> [I<line>] Delete the breakpoint for I<line>.
8304 B<D> Delete all breakpoints.
8305 B<a> [I<line>] I<command>
8306 Set an action to be done before the I<line> is executed;
8307 I<line> defaults to the current execution line.
8308 Sequence is: check for breakpoint/watchpoint, print line
8309 if necessary, do action, prompt user if necessary,
8311 B<a> [I<line>] Delete the action for I<line>.
8312 B<A> Delete all actions.
8313 B<W> I<expr> Add a global watch-expression.
8314 B<W> Delete all watch-expressions.
8315 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
8316 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
8317 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
8318 B<x> I<expr> Evals expression in list context, dumps the result.
8319 B<m> I<expr> Evals expression in list context, prints methods callable
8320 on the first element of the result.
8321 B<m> I<class> Prints methods callable via the given class.
8323 B<<> ? List Perl commands to run before each prompt.
8324 B<<> I<expr> Define Perl command to run before each prompt.
8325 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
8326 B<>> ? List Perl commands to run after each prompt.
8327 B<>> I<expr> Define Perl command to run after each prompt.
8328 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
8329 B<{> I<db_command> Define debugger command to run before each prompt.
8330 B<{> ? List debugger commands to run before each prompt.
8331 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
8332 B<$prc> I<number> Redo a previous command (default previous command).
8333 B<$prc> I<-number> Redo number'th-to-last command.
8334 B<$prc> I<pattern> Redo last command that started with I<pattern>.
8335 See 'B<O> I<recallCommand>' too.
8336 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
8341 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
8343 See 'B<O> I<shellBang>' too.
8344 B<source> I<file> Execute I<file> containing debugger commands (may nest).
8345 B<H> I<-number> Display last number commands (default all).
8346 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
8347 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
8348 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
8349 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
8350 I<command> Execute as a perl statement in current package.
8351 B<v> Show versions of loaded modules.
8352 B<R> Pure-man-restart of debugger, some of debugger state
8353 and command-line options may be lost.
8354 Currently the following settings are preserved:
8355 history, breakpoints and actions, debugger B<O>ptions
8356 and the following command-line options: I<-w>, I<-I>, I<-e>.
8358 B<O> [I<opt>] ... Set boolean option to true
8359 B<O> [I<opt>B<?>] Query options
8360 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
8361 Set options. Use quotes if spaces in value.
8362 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
8363 I<pager> program for output of \"|cmd\";
8364 I<tkRunning> run Tk while prompting (with ReadLine);
8365 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
8366 I<inhibit_exit> Allows stepping off the end of the script.
8367 I<ImmediateStop> Debugger should stop as early as possible.
8368 I<RemotePort> Remote hostname:port for remote debugging
8369 The following options affect what happens with B<V>, B<X>, and B<x> commands:
8370 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
8371 I<compactDump>, I<veryCompact> change style of array and hash dump;
8372 I<globPrint> whether to print contents of globs;
8373 I<DumpDBFiles> dump arrays holding debugged files;
8374 I<DumpPackages> dump symbol tables of packages;
8375 I<DumpReused> dump contents of \"reused\" addresses;
8376 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
8377 I<bareStringify> Do not print the overload-stringified value;
8378 Other options include:
8379 I<PrintRet> affects printing of return value after B<r> command,
8380 I<frame> affects printing messages on subroutine entry/exit.
8381 I<AutoTrace> affects printing messages on possible breaking points.
8382 I<maxTraceLen> gives max length of evals/args listed in stack trace.
8383 I<ornaments> affects screen appearance of the command line.
8384 I<CreateTTY> bits control attempts to create a new TTY on events:
8385 1: on fork() 2: debugger is started inside debugger
8387 During startup options are initialized from \$ENV{PERLDB_OPTS}.
8388 You can put additional initialization options I<TTY>, I<noTTY>,
8389 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
8390 B<R> after you set them).
8392 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
8393 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
8394 B<h h> Summary of debugger commands.
8395 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
8396 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
8397 Set B<\$DB::doccmd> to change viewer.
8399 Type '|h' for a paged display if this was too hard to read.
8401 "; # Fix balance of vi % matching: }}}}
8403 # note: tabs in the following section are not-so-helpful
8404 $pre580_summary = <<"END_SUM";
8405 I<List/search source lines:> I<Control script execution:>
8406 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
8407 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
8408 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
8409 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
8410 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
8411 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
8412 I<Debugger controls:> B<L> List break/watch/actions
8413 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
8414 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
8415 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
8416 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
8417 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
8418 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
8419 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
8420 B<q> or B<^D> Quit B<R> Attempt a restart
8421 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
8422 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
8423 B<p> I<expr> Print expression (uses script's current package).
8424 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
8425 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
8426 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
8427 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8428 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
8431 # ')}}; # Fix balance of vi % matching
8433 } ## end sub sethelp
8435 =head2 C<print_help()>
8437 Most of what C<print_help> does is just text formatting. It finds the
8438 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
8439 terminal control characters to simulate them (courtesy of
8440 C<Term::ReadLine::TermCap>).
8445 my $help_str = shift;
8447 # Restore proper alignment destroyed by eeevil I<> and B<>
8448 # ornaments: A pox on both their houses!
8450 # A help command will have everything up to and including
8451 # the first tab sequence padded into a field 16 (or if indented 20)
8452 # wide. If it's wider than that, an extra space will be added.
8454 ^ # only matters at start of line
8455 ( \ {4} | \t )* # some subcommands are indented
8456 ( < ? # so <CR> works
8457 [BI] < [^\t\n] + ) # find an eeevil ornament
8458 ( \t+ ) # original separation, discarded
8459 ( .* ) # this will now start (no earlier) than
8462 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
8463 my $clean = $command;
8464 $clean =~ s/[BI]<([^>]*)>/$1/g;
8466 # replace with this whole string:
8467 ($leadwhite ? " " x 4 : "")
8469 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
8474 $help_str =~ s{ # handle bold ornaments
8475 B < ( [^>] + | > ) >
8477 $Term::ReadLine::TermCap::rl_term_set[2]
8479 . $Term::ReadLine::TermCap::rl_term_set[3]
8482 $help_str =~ s{ # handle italic ornaments
8483 I < ( [^>] + | > ) >
8485 $Term::ReadLine::TermCap::rl_term_set[0]
8487 . $Term::ReadLine::TermCap::rl_term_set[1]
8491 print {$OUT} $help_str;
8494 } ## end sub print_help
8498 This routine does a lot of gyrations to be sure that the pager is C<less>.
8499 It checks for C<less> masquerading as C<more> and records the result in
8500 C<$fixed_less> so we don't have to go through doing the stats again.
8504 use vars qw($fixed_less);
8507 if ($pager =~ /\bless\b/)
8511 elsif ($pager =~ /\bmore\b/)
8513 # Nope, set to more. See what's out there.
8514 my @st_more = stat('/usr/bin/more');
8515 my @st_less = stat('/usr/bin/less');
8517 # is it really less, pretending to be more?
8521 && $st_more[0] == $st_less[0]
8522 && $st_more[1] == $st_less[1]
8532 # We already know if this is set.
8533 return if $fixed_less;
8535 # changes environment!
8536 # 'r' added so we don't do (slow) stats again.
8537 $fixed_less = 1 if _calc_is_less();
8540 } ## end sub fix_less
8542 =head1 DIE AND WARN MANAGEMENT
8546 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
8547 to debug a debugger problem.
8549 It does its best to report the error that occurred, and then forces the
8550 program, debugger, and everything to die.
8556 # No entry/exit messages.
8559 # No return value prints.
8562 # set the abort signal handling to the default (just terminate).
8563 $SIG{'ABRT'} = 'DEFAULT';
8565 # If we enter the signal handler recursively, kill myself with an
8566 # abort signal (so we just terminate).
8567 kill 'ABRT', $$ if $panic++;
8569 # If we can show detailed info, do so.
8570 if ( defined &Carp::longmess ) {
8572 # Don't recursively enter the warn handler, since we're carping.
8573 local $SIG{__WARN__} = '';
8575 # Skip two levels before reporting traceback: we're skipping
8576 # mydie and confess.
8577 local $Carp::CarpLevel = 2; # mydie + confess
8579 # Tell us all about it.
8580 _db_warn( Carp::longmess("Signal @_") );
8583 # No Carp. Tell us about the signal as best we can.
8586 print $DB::OUT "Got signal @_\n";
8591 } ## end sub diesignal
8595 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
8596 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
8602 # No entry/exit trace.
8605 # No return value printing.
8608 # Turn off warn and die handling to prevent recursive entries to this
8610 local $SIG{__WARN__} = '';
8611 local $SIG{__DIE__} = '';
8613 # Load Carp if we can. If $^S is false (current thing being compiled isn't
8614 # done yet), we may not be able to do a require.
8615 eval { require Carp }
8616 if defined $^S; # If error/warning during compilation,
8617 # require may be broken.
8619 # Use the core warn() unless Carp loaded OK.
8621 "\nCannot print stack trace, load with -MCarp option to see stack" ),
8623 unless defined &Carp::longmess;
8625 # Save the current values of $single and $trace, and then turn them off.
8626 my ( $mysingle, $mytrace ) = ( $single, $trace );
8630 # We can call Carp::longmess without its being "debugged" (which we
8631 # don't want - we just want to use it!). Capture this for later.
8632 my $mess = Carp::longmess(@_);
8634 # Restore $single and $trace to their original values.
8635 ( $single, $trace ) = ( $mysingle, $mytrace );
8637 # Use the debugger's own special way of printing warnings to print
8638 # the stack trace message.
8644 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
8645 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
8646 single stepping and tracing during the call to C<Carp::longmess> to avoid
8647 debugging it - we just want to use it.
8649 If C<dieLevel> is zero, we let the program being debugged handle the
8650 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
8651 the debugger takes over all exception handling, printing a backtrace and
8652 displaying the exception via its C<dbwarn()> routine.
8659 local $SIG{__DIE__} = '';
8660 local $SIG{__WARN__} = '';
8661 if ( $dieLevel > 2 ) {
8662 local $SIG{__WARN__} = \&dbwarn;
8663 _db_warn(@_); # Yell no matter what
8666 if ( $dieLevel < 2 ) {
8667 die @_ if $^S; # in eval propagate
8670 # The code used to check $^S to see if compilation of the current thing
8671 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
8672 eval { require Carp };
8675 "\nCannot print stack trace, load with -MCarp option to see stack" )
8676 unless defined &Carp::longmess;
8678 # We do not want to debug this chunk (automatic disabling works
8679 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
8680 # get the stack trace from Carp::longmess (if possible), restore $signal
8681 # and $trace, and then die with the stack trace.
8682 my ( $mysingle, $mytrace ) = ( $single, $trace );
8688 package Carp; # Do not include us in the list
8689 eval { $mess = Carp::longmess(@_); };
8691 ( $single, $trace ) = ( $mysingle, $mytrace );
8695 =head2 C<warnlevel()>
8697 Set the C<$DB::warnLevel> variable that stores the value of the
8698 C<warnLevel> option. Calling C<warnLevel()> with a positive value
8699 results in the debugger taking over all warning handlers. Setting
8700 C<warnLevel> to zero leaves any warning handlers set up by the program
8701 being debugged in place.
8707 my $prevwarn = $SIG{__WARN__} unless $warnLevel;
8710 $SIG{__WARN__} = \&DB::dbwarn;
8713 $SIG{__WARN__} = $prevwarn;
8715 undef $SIG{__WARN__};
8719 } ## end sub warnLevel
8723 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
8724 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
8725 zero lets you use your own C<die()> handler.
8732 my $prevdie = $SIG{__DIE__} unless $dieLevel;
8736 # Always set it to dbdie() for non-zero values.
8737 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
8739 # No longer exists, so don't try to use it.
8740 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
8742 # If we've finished initialization, mention that stack dumps
8743 # are enabled, If dieLevel is 1, we won't stack dump if we die
8745 print $OUT "Stack dump during die enabled",
8746 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
8749 # XXX This is probably obsolete, given that diehard() is gone.
8750 print $OUT "Dump printed too.\n" if $dieLevel > 2;
8751 } ## end if ($dieLevel)
8753 # Put the old one back if there was one.
8755 $SIG{__DIE__} = $prevdie;
8756 print $OUT "Default die handler restored.\n";
8758 undef $SIG{__DIE__};
8759 print $OUT "Die handler removed.\n";
8763 } ## end sub dieLevel
8765 =head2 C<signalLevel>
8767 Number three in a series: set C<signalLevel> to zero to keep your own
8768 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
8769 takes over and handles them with C<DB::diesignal()>.
8775 my $prevsegv = $SIG{SEGV} unless $signalLevel;
8776 my $prevbus = $SIG{BUS} unless $signalLevel;
8777 $signalLevel = shift;
8779 $SIG{SEGV} = \&DB::diesignal;
8780 $SIG{BUS} = \&DB::diesignal;
8783 $SIG{SEGV} = $prevsegv;
8784 $SIG{BUS} = $prevbus;
8788 } ## end sub signalLevel
8790 =head1 SUBROUTINE DECODING SUPPORT
8792 These subroutines are used during the C<x> and C<X> commands to try to
8793 produce as much information as possible about a code reference. They use
8794 L<Devel::Peek> to try to find the glob in which this code reference lives
8795 (if it does) - this allows us to actually code references which correspond
8796 to named subroutines (including those aliased via glob assignment).
8798 =head2 C<CvGV_name()>
8800 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
8801 via that routine. If this fails, return the reference again (when the
8802 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
8808 my $name = CvGV_name_or_bust($in);
8809 defined $name ? $name : $in;
8812 =head2 C<CvGV_name_or_bust> I<coderef>
8814 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
8815 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
8816 find a glob for this ref.
8818 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
8822 use vars qw($skipCvGV);
8824 sub CvGV_name_or_bust {
8826 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
8827 return unless ref $in;
8828 $in = \&$in; # Hard reference...
8829 eval { require Devel::Peek; 1 } or return;
8830 my $gv = Devel::Peek::CvGV($in) or return;
8831 *$gv{PACKAGE} . '::' . *$gv{NAME};
8832 } ## end sub CvGV_name_or_bust
8836 A utility routine used in various places; finds the file where a subroutine
8837 was defined, and returns that filename and a line-number range.
8839 Tries to use C<@sub> first; if it can't find it there, it tries building a
8840 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
8841 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
8842 this way, it brute-force searches C<%sub>, checking for identical references.
8846 sub _find_sub_helper {
8849 return unless defined &$subr;
8850 my $name = CvGV_name_or_bust($subr);
8852 $data = $sub{$name} if defined $name;
8853 return $data if defined $data;
8856 $subr = \&$subr; # Hard reference
8859 $s = $_, last if $subr eq \&$_;
8874 return ( $sub{$subr} || _find_sub_helper($subr) );
8875 } ## end sub find_sub
8879 A subroutine that uses the utility function C<methods_via> to find all the
8880 methods in the class corresponding to the current reference and in
8889 # Figure out the class - either this is the class or it's a reference
8890 # to something blessed into that class.
8892 $class = ref $class if ref $class;
8896 # Show the methods that this class has.
8897 methods_via( $class, '', 1 );
8899 # Show the methods that UNIVERSAL has.
8900 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
8901 } ## end sub methods
8903 =head2 C<methods_via($class, $prefix, $crawl_upward)>
8905 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
8906 all the parent class methods. C<$class> is the name of the next class to
8907 try; C<$prefix> is the message prefix, which gets built up as we go up the
8908 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
8909 higher in the C<@ISA> tree, 0 if we should stop.
8915 # If we've processed this class already, just quit.
8917 return if $seen{$class}++;
8919 # This is a package that is contributing the methods we're about to print.
8921 my $prepend = $prefix ? "via $prefix: " : '';
8924 # Extract from all the symbols in this class.
8925 my $class_ref = do { no strict "refs"; \%{$class . '::'} };
8926 while (my ($name, $glob) = each %$class_ref) {
8927 # references directly in the symbol table are Proxy Constant
8928 # Subroutines, and are by their very nature defined
8929 # Otherwise, check if the thing is a typeglob, and if it is, it decays
8930 # to a subroutine reference, which can be tested by defined.
8931 # $glob might also be the value -1 (from sub foo;)
8932 # or (say) '$$' (from sub foo ($$);)
8933 # \$glob will be SCALAR in both cases.
8934 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob))
8935 && !$seen{$name}++) {
8936 push @to_print, "$prepend$name\n";
8943 print $DB::OUT $_ foreach sort @to_print;
8946 # If the $crawl_upward argument is false, just quit here.
8947 return unless shift;
8949 # $crawl_upward true: keep going up the tree.
8950 # Find all the classes this one is a subclass of.
8951 my $class_ISA_ref = do { no strict "refs"; \@{"${class}::ISA"} };
8952 for my $name ( @$class_ISA_ref ) {
8954 # Set up the new prefix.
8955 $prepend = $prefix ? $prefix . " -> $name" : $name;
8957 # Crawl up the tree and keep trying to crawl up.
8958 methods_via( $name, $prepend, 1 );
8960 } ## end sub methods_via
8962 =head2 C<setman> - figure out which command to use to show documentation
8964 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8969 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|NetWare)\z/s
8970 ? "man" # O Happy Day!
8971 : "perldoc"; # Alas, poor unfortunates
8974 =head2 C<runman> - run the appropriate command to show documentation
8976 Accepts a man page name; runs the appropriate command to display it (set up
8977 during debugger initialization). Uses C<_db_system()> to avoid mucking up the
8978 program's STDIN and STDOUT.
8985 _db_system("$doccmd $doccmd");
8989 # this way user can override, like with $doccmd="man -Mwhatever"
8990 # or even just "man " to disable the path check.
8991 if ( $doccmd ne 'man' ) {
8992 _db_system("$doccmd $page");
8996 $page = 'perl' if lc($page) eq 'help';
8999 my $man1dir = $Config::Config{man1direxp};
9000 my $man3dir = $Config::Config{man3direxp};
9001 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
9003 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
9004 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
9005 chop $manpath if $manpath;
9007 # harmless if missing, I figure
9008 local $ENV{MANPATH} = $manpath if $manpath;
9009 my $nopathopt = $^O =~ /dunno what goes here/;
9014 # I just *know* there are men without -M
9015 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
9020 unless ( $page =~ /^perl\w/ ) {
9021 # Previously the debugger contained a list which it slurped in,
9022 # listing the known "perl" manpages. However, it was out of date,
9023 # with errors both of omission and inclusion. This approach is
9024 # considerably less complex. The failure mode on a butchered
9025 # install is simply that the user has to run man or perldoc
9026 # "manually" with the full manpage name.
9028 # There is a list of $^O values in installperl to determine whether
9029 # the directory is 'pods' or 'pod'. However, we can avoid tight
9030 # coupling to that by simply checking the "non-standard" 'pods'
9032 my $pods = "$Config::Config{privlibexp}/pods";
9033 $pods = "$Config::Config{privlibexp}/pod"
9035 if (-f "$pods/perl$page.pod") {
9036 CORE::system( $doccmd,
9037 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
9041 } ## end if (CORE::system($doccmd...
9044 #use Carp; # This did break, left for debugging
9046 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
9048 Because of the way the debugger interface to the Perl core is designed, any
9049 debugger package globals that C<DB::sub()> requires have to be defined before
9050 any subroutines can be called. These are defined in the second C<BEGIN> block.
9052 This block sets things up so that (basically) the world is sane
9053 before the debugger starts executing. We set up various variables that the
9054 debugger has to have set up before the Perl core starts running:
9060 The debugger's own filehandles (copies of STD and STDOUT for now).
9064 Characters for shell escapes, the recall command, and the history command.
9068 The maximum recursion depth.
9072 The size of a C<w> command's window.
9076 The before-this-line context to be printed in a C<v> (view a window around this line) command.
9080 The fact that we're not in a sub at all right now.
9084 The default SIGINT handler for the debugger.
9088 The appropriate value of the flag in C<$^D> that says the debugger is running
9092 The current debugger recursion level
9096 The list of postponed items and the C<$single> stack (XXX define this)
9100 That we want no return values and no subroutine entry/exit trace.
9106 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
9108 use vars qw($db_stop);
9110 BEGIN { # This does not compile, alas. (XXX eh?)
9111 $IN = \*STDIN; # For bugs before DB::OUT has been opened
9112 $OUT = \*STDERR; # For errors before DB::OUT has been opened
9114 # Define characters used by command parsing.
9115 $sh = '!'; # Shell escape (does not work)
9116 $rc = ','; # Recall command (does not work)
9117 @hist = ('?'); # Show history (does not work)
9118 @truehist = (); # Can be saved for replay (per session)
9120 # This defines the point at which you get the 'deep recursion'
9121 # warning. It MUST be defined or the debugger will not load.
9124 # Number of lines around the current one that are shown in the
9128 # How much before-the-current-line context the 'v' command should
9129 # use in calculating the start of the window it will display.
9132 # We're not in any sub yet, but we need this to be a defined value.
9135 # Set up the debugger's interrupt handler. It simply sets a flag
9136 # ($signal) that DB::DB() will check before each command is executed.
9137 $SIG{INT} = \&DB::catch;
9139 # The following lines supposedly, if uncommented, allow the debugger to
9140 # debug itself. Perhaps we can try that someday.
9141 # This may be enabled to debug debugger:
9142 #$warnLevel = 1 unless defined $warnLevel;
9143 #$dieLevel = 1 unless defined $dieLevel;
9144 #$signalLevel = 1 unless defined $signalLevel;
9146 # This is the flag that says "a debugger is running, please call
9147 # DB::DB and DB::sub". We will turn it on forcibly before we try to
9148 # execute anything in the user's context, because we always want to
9150 $db_stop = 0; # Compiler warning ...
9151 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
9153 # This variable records how many levels we're nested in debugging. Used
9154 # Used in the debugger prompt, and in determining whether it's all over or
9156 $level = 0; # Level of recursive debugging
9158 # "Triggers bug (?) in perl if we postpone this until runtime."
9159 # XXX No details on this yet, or whether we should fix the bug instead
9160 # of work around it. Stay tuned.
9163 # Used to track the current stack depth using the auto-stacked-variable
9165 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
9167 # Don't print return values on exiting a subroutine.
9170 # No extry/exit tracing.
9175 BEGIN { $^W = $ini_warn; } # Switch warnings back
9177 =head1 READLINE SUPPORT - COMPLETION FUNCTION
9181 C<readline> support - adds command completion to basic C<readline>.
9183 Returns a list of possible completions to C<readline> when invoked. C<readline>
9184 will print the longest common substring following the text already entered.
9186 If there is only a single possible completion, C<readline> will use it in full.
9188 This code uses C<map> and C<grep> heavily to create lists of possible
9189 completion. Think LISP in this section.
9195 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
9196 # $text is the text to be completed.
9197 # $line is the incoming line typed by the user.
9198 # $start is the start of the text to be completed in the incoming line.
9199 my ( $text, $line, $start ) = @_;
9201 # Save the initial text.
9202 # The search pattern is current package, ::, extract the next qualifier
9203 # Prefix and pack are set to undef.
9204 my ( $itext, $search, $prefix, $pack ) =
9205 ( $text, "^\Q${package}::\E([^:]+)\$" );
9207 =head3 C<b postpone|compile>
9213 Find all the subroutines that might match in this package
9217 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
9221 Include all the rest of the subs that are known
9225 C<grep> out the ones that match the text we have so far
9229 Return this as the list of possible completions
9235 return sort grep /^\Q$text/, ( keys %sub ),
9236 qw(postpone load compile), # subroutines
9237 ( map { /$search/ ? ($1) : () } keys %sub )
9238 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
9242 Get all the possible files from C<@INC> as it currently stands and
9243 select the ones that match the text so far.
9247 return sort grep /^\Q$text/, values %INC # files
9248 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
9250 =head3 C<V> (list variable) and C<m> (list modules)
9252 There are two entry points for these commands:
9254 =head4 Unqualified package names
9256 Get the top-level packages and grab everything that matches the text
9257 so far. For each match, recursively complete the partial packages to
9258 get all possible matching packages. Return this sorted list.
9262 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9263 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
9264 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
9266 =head4 Qualified package names
9268 Take a partially-qualified package and find all subpackages for it
9269 by getting all the subpackages for the package so far, matching all
9270 the subpackages against the text, and discarding all of them which
9271 start with 'main::'. Return this list.
9275 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9276 grep !/^main::/, grep /^\Q$text/,
9277 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () }
9278 do { no strict 'refs'; keys %{ $prefix . '::' } }
9279 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
9280 and $text =~ /^(.*[^:])::?(\w*)$/
9283 =head3 C<f> - switch files
9285 Here, we want to get a fully-qualified filename for the C<f> command.
9290 =item 1. The original source file itself
9292 =item 2. A file from C<@INC>
9294 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
9300 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
9301 # We might possibly want to switch to an eval (which has a "filename"
9302 # like '(eval 9)'), so we may need to clean up the completion text
9303 # before proceeding.
9304 $prefix = length($1) - length($text);
9309 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
9310 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
9311 out of C<%main::>, add the initial source file, and extract the ones that
9312 match the completion text so far.
9317 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
9319 } ## end if ($line =~ /^\|*f\s+(.*)/)
9321 =head3 Subroutine name completion
9323 We look through all of the defined subs (the keys of C<%sub>) and
9324 return both all the possible matches to the subroutine name plus
9325 all the matches qualified to the current package.
9329 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
9330 $text = substr $text, 1;
9332 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
9334 map { /$search/ ? ($1) : () }
9337 } ## end if ((substr $text, 0, ...
9339 =head3 Scalar, array, and hash completion: partially qualified package
9341 Much like the above, except we have to do a little more cleanup:
9345 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
9353 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
9357 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
9363 Figure out the prefix vs. what needs completing.
9367 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
9374 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
9380 map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
9388 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.
9392 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9393 return db_complete( $out[0], $line, $start );
9396 # Return the list of possibles.
9399 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
9405 =head3 Symbol completion: current package or package C<main>.
9409 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
9416 If it's C<main>, delete main to just get C<::> leading.
9420 $pack = ( $package eq 'main' ? '' : $package ) . '::';
9426 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
9430 $prefix = substr $text, 0, 1;
9431 $text = substr $text, 1;
9439 We look for the lexical scope above DB::DB and auto-complete lexical variables
9440 if PadWalker could be loaded.
9444 if (not $text =~ /::/ and eval { require PadWalker } ) {
9447 my @info = caller($level);
9451 last if $info[3] eq 'DB::DB';
9454 my $lexicals = PadWalker::peek_my($level);
9455 push @out, grep /^\Q$prefix$text/, keys %$lexicals;
9463 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
9467 push @out, map "$prefix$_", grep /^\Q$text/,
9468 ( grep /^_?[a-zA-Z]/, do { no strict 'refs'; keys %$pack } ),
9469 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
9473 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
9479 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9480 return db_complete( $out[0], $line, $start );
9483 # Return the list of possibles.
9485 } ## end if ($text =~ /^[\$@%]/)
9489 We use C<option_val()> to look up the current value of the option. If there's
9490 only a single value, we complete the command in such a way that it is a
9491 complete command for setting the option in question. If there are multiple
9492 possible values, we generate a command consisting of the option plus a trailing
9493 question mark, which, if executed, will list the current value of the option.
9497 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
9498 { # Options after space
9499 # We look for the text to be matched in the list of possible options,
9500 # and fetch the current value.
9501 my @out = grep /^\Q$text/, @options;
9502 my $val = option_val( $out[0], undef );
9504 # Set up a 'query option's value' command.
9506 if ( not defined $val or $val =~ /[\n\r]/ ) {
9508 # There's really nothing else we can do.
9511 # We have a value. Create a proper option-setting command.
9512 elsif ( $val =~ /\s/ ) {
9514 # XXX This may be an extraneous variable.
9517 # We'll want to quote the string (because of the embedded
9518 # whtespace), but we want to make sure we don't end up with
9519 # mismatched quote characters. We try several possibilities.
9520 foreach my $l ( split //, qq/\"\'\#\|/ ) {
9522 # If we didn't find this quote character in the value,
9523 # quote it using this quote character.
9524 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
9526 } ## end elsif ($val =~ /\s/)
9528 # Don't need any quotes.
9533 # If there were multiple possible values, return '? ', which
9534 # makes the command into a query command. If there was just one,
9535 # have readline append that.
9536 $rl_attribs->{completer_terminator_character} =
9537 ( @out == 1 ? $out : '? ' );
9539 # Return list of possibilities.
9541 } ## end if ((substr $line, 0, ...
9543 =head3 Filename completion
9545 For entering filenames. We simply call C<readline>'s C<filename_list()>
9546 method with the completion text to get the possible completions.
9550 return $term->filename_list($text); # filenames
9552 } ## end sub db_complete
9554 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
9556 Functions that possibly ought to be somewhere else.
9566 print $OUT "Use 'q' to quit or 'R' to restart. 'h q' for details.\n";
9571 If we have $ini_pids, save it in the environment; else remove it from the
9572 environment. Used by the C<R> (restart) command.
9577 if ( defined($ini_pids) ) {
9578 $ENV{PERLDB_PIDS} = $ini_pids;
9581 delete( $ENV{PERLDB_PIDS} );
9583 } ## end sub clean_ENV
9585 # PERLDBf_... flag names from perl.h
9586 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
9589 %DollarCaretP_flags = (
9590 PERLDBf_SUB => 0x01, # Debug sub enter/exit
9591 PERLDBf_LINE => 0x02, # Keep line #
9592 PERLDBf_NOOPT => 0x04, # Switch off optimizations
9593 PERLDBf_INTER => 0x08, # Preserve more data
9594 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
9595 PERLDBf_SINGLE => 0x20, # Start with single-step on
9596 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
9597 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
9598 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
9599 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
9600 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"}
9601 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO
9603 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger
9604 # doesn't need to set it. It's provided for the benefit of profilers and
9605 # other code analysers.
9607 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
9610 sub parse_DollarCaretP_flags {
9615 foreach my $f ( split /\s*\|\s*/, $flags ) {
9617 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
9620 elsif ( $f =~ /^(\d+)$/ ) {
9623 elsif ( $f =~ /^DEFAULT$/i ) {
9624 $value = $DollarCaretP_flags{PERLDB_ALL};
9627 $f =~ /^(?:PERLDBf_)?(.*)$/i;
9628 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
9629 unless ( defined $value ) {
9631 "Unrecognized \$^P flag '$f'!\n",
9632 "Acceptable flags are: "
9633 . join( ', ', sort keys %DollarCaretP_flags ),
9634 ", and hexadecimal and decimal numbers.\n"
9644 sub expand_DollarCaretP_flags {
9645 my $DollarCaretP = shift;
9648 my $n = ( 1 << $_ );
9649 ( $DollarCaretP & $n )
9650 ? ( $DollarCaretP_flags_r{$n}
9651 || sprintf( '0x%x', $n ) )
9655 return @bits ? join( '|', @bits ) : 0;
9662 Rerun the current session to:
9664 rerun current position
9666 rerun 4 command number 4
9668 rerun -4 current command minus 4 (go back 4 steps)
9670 Whether this always makes sense, in the current context is unknowable, and is
9671 in part left as a useful exercise for the reader. This sub returns the
9672 appropriate arguments to rerun the current session.
9679 pop(@truehist); # strim
9680 unless (defined $truehist[$i]) {
9681 print "Unable to return to non-existent command: $i\n";
9683 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
9684 my @temp = @truehist; # store
9685 push(@DB::typeahead, @truehist); # saved
9686 @truehist = @hist = (); # flush
9687 @args = restart(); # setup
9688 get_list("PERLDB_HIST"); # clean
9689 set_list("PERLDB_HIST", @temp); # reset
9696 Restarting the debugger is a complex operation that occurs in several phases.
9697 First, we try to reconstruct the command line that was used to invoke Perl
9703 # I may not be able to resurrect you, but here goes ...
9705 "Warning: some settings and command-line options may be lost!\n";
9706 my ( @script, @flags, $cl );
9708 # If warn was on before, turn it on again.
9709 push @flags, '-w' if $ini_warn;
9711 # Rebuild the -I flags that were on the initial
9714 push @flags, '-I', $_;
9717 # Turn on taint if it was on before.
9718 push @flags, '-T' if ${^TAINT};
9720 # Arrange for setting the old INC:
9721 # Save the current @init_INC in the environment.
9722 set_list( "PERLDB_INC", @ini_INC );
9724 # If this was a perl one-liner, go to the "file"
9725 # corresponding to the one-liner read all the lines
9726 # out of it (except for the first one, which is going
9727 # to be added back on again when 'perl -d' runs: that's
9728 # the 'require perl5db.pl;' line), and add them back on
9729 # to the command line to be executed.
9731 my $lines = *{$main::{'_<-e'}}{ARRAY};
9732 for ( 1 .. $#$lines ) { # The first line is PERL5DB
9733 chomp( $cl = $lines->[$_] );
9734 push @script, '-e', $cl;
9736 } ## end if ($0 eq '-e')
9738 # Otherwise we just reuse the original name we had
9746 After the command line has been reconstructed, the next step is to save
9747 the debugger's status in environment variables. The C<DB::set_list> routine
9748 is used to save aggregate variables (both hashes and arrays); scalars are
9749 just popped into environment variables directly.
9753 # If the terminal supported history, grab it and
9754 # save that in the environment.
9755 set_list( "PERLDB_HIST",
9756 $term->Features->{getHistory}
9760 # Find all the files that were visited during this
9761 # session (i.e., the debugger had magic hashes
9762 # corresponding to them) and stick them in the environment.
9763 my @had_breakpoints = keys %had_breakpoints;
9764 set_list( "PERLDB_VISITED", @had_breakpoints );
9766 # Save the debugger options we chose.
9767 set_list( "PERLDB_OPT", %option );
9768 # set_list( "PERLDB_OPT", options2remember() );
9770 # Save the break-on-loads.
9771 set_list( "PERLDB_ON_LOAD", %break_on_load );
9775 The most complex part of this is the saving of all of the breakpoints. They
9776 can live in an awful lot of places, and we have to go through all of them,
9777 find the breakpoints, and then save them in the appropriate environment
9778 variable via C<DB::set_list>.
9782 # Go through all the breakpoints and make sure they're
9785 for ( 0 .. $#had_breakpoints ) {
9787 # We were in this file.
9788 my $file = $had_breakpoints[$_];
9790 # Grab that file's magic line hash.
9791 *dbline = $main::{ '_<' . $file };
9793 # Skip out if it doesn't exist, or if the breakpoint
9794 # is in a postponed file (we'll do postponed ones
9796 next unless %dbline or $postponed_file{$file};
9798 # In an eval. This is a little harder, so we'll
9799 # do more processing on that below.
9800 ( push @hard, $file ), next
9801 if $file =~ /^\(\w*eval/;
9803 # XXX I have no idea what this is doing. Yet.
9805 @add = %{ $postponed_file{$file} }
9806 if $postponed_file{$file};
9808 # Save the list of all the breakpoints for this file.
9809 set_list( "PERLDB_FILE_$_", %dbline, @add );
9811 # Serialize the extra data %breakpoints_data hash.
9813 set_list( "PERLDB_FILE_ENABLED_$_",
9814 map { _is_breakpoint_enabled($file, $_) ? 1 : 0 }
9815 sort { $a <=> $b } keys(%dbline)
9817 } ## end for (0 .. $#had_breakpoints)
9819 # The breakpoint was inside an eval. This is a little
9820 # more difficult. XXX and I don't understand it.
9821 foreach my $hard_file (@hard) {
9822 # Get over to the eval in question.
9823 *dbline = $main::{ '_<' . $hard_file };
9824 my $quoted = quotemeta $hard_file;
9826 for my $sub ( keys %sub ) {
9827 if (my ($n1, $n2) = $sub{$sub} =~ /\A$quoted:(\d+)-(\d+)\z/) {
9828 $subs{$sub} = [ $n1, $n2 ];
9833 "No subroutines in $hard_file, ignoring breakpoints.\n";
9836 LINES: foreach my $line ( keys %dbline ) {
9838 # One breakpoint per sub only:
9839 my ( $offset, $found );
9840 SUBS: foreach my $sub ( keys %subs ) {
9842 $subs{$sub}->[1] >= $line # Not after the subroutine
9844 not defined $offset # Not caught
9850 $offset = $line - $subs{$sub}->[0];
9852 $offset = "+$offset";
9855 } ## end if ($subs{$sub}->[1] >=...
9856 } ## end for $sub (keys %subs)
9857 if ( defined $offset ) {
9858 $postponed{$found} =
9859 "break $offset if $dbline{$line}";
9863 ("Breakpoint in ${hard_file}:$line ignored:"
9864 . " after all the subroutines.\n");
9866 } ## end for $line (keys %dbline)
9867 } ## end for (@hard)
9869 # Save the other things that don't need to be
9871 set_list( "PERLDB_POSTPONE", %postponed );
9872 set_list( "PERLDB_PRETYPE", @$pretype );
9873 set_list( "PERLDB_PRE", @$pre );
9874 set_list( "PERLDB_POST", @$post );
9875 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9877 # We are officially restarting.
9878 $ENV{PERLDB_RESTART} = 1;
9880 # We are junking all child debuggers.
9881 delete $ENV{PERLDB_PIDS}; # Restore ini state
9883 # Set this back to the initial pid.
9884 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9888 After all the debugger status has been saved, we take the command we built up
9889 and then return it, so we can C<exec()> it. The debugger will spot the
9890 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9891 from the environment.
9895 # And run Perl again. Add the "-d" flag, all the
9896 # flags we built up, the script (whether a one-liner
9897 # or a file), add on the -emacs flag for a slave editor,
9898 # and then the old arguments.
9900 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9906 =head1 END PROCESSING - THE C<END> BLOCK
9908 Come here at the very end of processing. We want to go into a
9909 loop where we allow the user to enter commands and interact with the
9910 debugger, but we don't want anything else to execute.
9912 First we set the C<$finished> variable, so that some commands that
9913 shouldn't be run after the end of program quit working.
9915 We then figure out whether we're truly done (as in the user entered a C<q>
9916 command, or we finished execution while running nonstop). If we aren't,
9917 we set C<$single> to 1 (causing the debugger to get control again).
9919 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9920 message and returns control to the debugger. Repeat.
9922 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9923 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9924 break, run to completion.).
9929 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9930 $fall_off_end = 1 unless $inhibit_exit;
9932 # Do not stop in at_exit() and destructors on exit:
9933 if ($fall_off_end or $runnonstop) {
9937 DB::fake::at_exit();
9941 =head1 PRE-5.8 COMMANDS
9943 Some of the commands changed function quite a bit in the 5.8 command
9944 realignment, so much so that the old code had to be replaced completely.
9945 Because we wanted to retain the option of being able to go back to the
9946 former command set, we moved the old code off to this section.
9948 There's an awful lot of duplicated code here. We've duplicated the
9949 comments to keep things clear.
9953 Does nothing. Used to I<turn off> commands.
9957 sub cmd_pre580_null {
9962 =head2 Old C<a> command.
9964 This version added actions if you supplied them, and deleted them
9973 # Argument supplied. Add the action.
9974 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9976 # If the line isn't there, use the current line.
9977 my $i = $1 || $line;
9980 # If there is an action ...
9983 # ... but the line isn't breakable, skip it.
9984 if ( $dbline[$i] == 0 ) {
9985 print $OUT "Line $i may not have an action.\n";
9989 # ... and the line is breakable:
9990 # Mark that there's an action in this file.
9991 $had_breakpoints{$filename} |= 2;
9993 # Delete any current action.
9994 $dbline{$i} =~ s/\0[^\0]*//;
9996 # Add the new action, continuing the line as needed.
9997 $dbline{$i} .= "\0" . action($j);
9999 } ## end if (length $j)
10001 # No action supplied.
10004 # Delete the action.
10005 $dbline{$i} =~ s/\0[^\0]*//;
10007 # Mark as having no break or action if nothing's left.
10008 delete $dbline{$i} if $dbline{$i} eq '';
10010 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
10011 } ## end sub cmd_pre580_a
10013 =head2 Old C<b> command
10022 my $dbline = shift;
10025 if ( $cmd =~ /^load\b\s*(.*)/ ) {
10031 # b compile|postpone <some sub> [<condition>]
10032 # The interpreter actually traps this one for us; we just put the
10033 # necessary condition in the %postponed hash.
10034 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
10036 # Capture the condition if there is one. Make it true if none.
10037 my $cond = length $3 ? $3 : '1';
10039 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
10040 # if it was 'compile'.
10041 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
10043 # De-Perl4-ify the name - ' separators to ::.
10044 $subname =~ s/\'/::/g;
10046 # Qualify it into the current package unless it's already qualified.
10047 $subname = "${package}::" . $subname
10048 unless $subname =~ /::/;
10050 # Add main if it starts with ::.
10051 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
10053 # Save the break type for this sub.
10054 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
10055 } ## end elsif ($cmd =~ ...
10057 # b <sub name> [<condition>]
10058 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
10060 my $cond = length $2 ? $2 : '1';
10061 cmd_b_sub( $subname, $cond );
10063 # b <line> [<condition>].
10064 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
10065 my $i = $1 || $dbline;
10066 my $cond = length $2 ? $2 : '1';
10067 cmd_b_line( $i, $cond );
10069 } ## end sub cmd_pre580_b
10071 =head2 Old C<D> command.
10073 Delete all breakpoints unconditionally.
10080 if ( $cmd =~ /^\s*$/ ) {
10081 print $OUT "Deleting all breakpoints...\n";
10083 # %had_breakpoints lists every file that had at least one
10084 # breakpoint in it.
10086 for $file ( keys %had_breakpoints ) {
10088 # Switch to the desired file temporarily.
10089 local *dbline = $main::{ '_<' . $file };
10094 # For all lines in this file ...
10095 for my $i (1 .. $max) {
10097 # If there's a breakpoint or action on this line ...
10098 if ( defined $dbline{$i} ) {
10100 # ... remove the breakpoint.
10101 $dbline{$i} =~ s/^[^\0]+//;
10102 if ( $dbline{$i} =~ s/^\0?$// ) {
10104 # Remove the entry altogether if no action is there.
10105 delete $dbline{$i};
10107 } ## end if (defined $dbline{$i...
10108 } ## end for my $i (1 .. $max)
10110 # If, after we turn off the "there were breakpoints in this file"
10111 # bit, the entry in %had_breakpoints for this file is zero,
10112 # we should remove this file from the hash.
10113 if ( not $had_breakpoints{$file} &= ~1 ) {
10114 delete $had_breakpoints{$file};
10116 } ## end for $file (keys %had_breakpoints)
10118 # Kill off all the other breakpoints that are waiting for files that
10119 # haven't been loaded yet.
10121 undef %postponed_file;
10122 undef %break_on_load;
10123 } ## end if ($cmd =~ /^\s*$/)
10124 } ## end sub cmd_pre580_D
10126 =head2 Old C<h> command
10128 Print help. Defaults to printing the long-form help; the 5.8 version
10129 prints the summary by default.
10137 # Print the *right* help, long format.
10138 if ( $cmd =~ /^\s*$/ ) {
10139 print_help($pre580_help);
10142 # 'h h' - explicitly-requested summary.
10143 elsif ( $cmd =~ /^h\s*/ ) {
10144 print_help($pre580_summary);
10147 # Find and print a command's help.
10148 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
10149 my $asked = $1; # for proper errmsg
10150 my $qasked = quotemeta($asked); # for searching
10151 # XXX: finds CR but not <CR>
10155 (?:[IB]<) # Optional markup
10156 $qasked # The command name
10163 ( # The command help:
10165 (?:[IB]<) # Optional markup
10166 $qasked # The command name
10167 ([\s\S]*?) # Lines starting with tabs
10171 ) # Line not starting with space
10172 # (Next command's help)
10176 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
10180 print_help("B<$asked> is not a debugger command.\n");
10182 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
10183 } ## end sub cmd_pre580_h
10185 =head2 Old C<W> command
10187 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
10195 # Delete all watch expressions.
10196 if ( $cmd =~ /^$/ ) {
10198 # No watching is going on.
10201 # Kill all the watch expressions and values.
10202 @to_watch = @old_watch = ();
10205 # Add a watch expression.
10206 elsif ( $cmd =~ /^(.*)/s ) {
10208 # add it to the list to be watched.
10209 push @to_watch, $1;
10211 # Get the current value of the expression.
10212 # Doesn't handle expressions returning list values!
10214 # The &-call is here to ascertain the mutability of @_.
10215 my ($val) = &DB::eval;
10216 $val = ( defined $val ) ? "'$val'" : 'undef';
10219 push @old_watch, $val;
10221 # We're watching stuff.
10224 } ## end elsif ($cmd =~ /^(.*)/s)
10225 } ## end sub cmd_pre580_W
10227 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
10229 The debugger used to have a bunch of nearly-identical code to handle
10230 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
10231 C<cmd_prepost> unify all this into one set of code to handle the
10232 appropriate actions.
10234 =head2 C<cmd_pre590_prepost>
10236 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
10237 do something destructive. In pre 5.8 debuggers, the default action was to
10238 delete all the actions.
10242 sub cmd_pre590_prepost {
10244 my $line = shift || '*';
10245 my $dbline = shift;
10247 return cmd_prepost( $cmd, $line, $dbline );
10248 } ## end sub cmd_pre590_prepost
10250 =head2 C<cmd_prepost>
10252 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
10253 Since the lists of actions are all held in arrays that are pointed to by
10254 references anyway, all we have to do is pick the right array reference and
10255 then use generic code to all, delete, or list actions.
10262 # No action supplied defaults to 'list'.
10263 my $line = shift || '?';
10265 # Figure out what to put in the prompt.
10268 # Make sure we have some array or another to address later.
10269 # This means that if for some reason the tests fail, we won't be
10270 # trying to stash actions or delete them from the wrong place.
10273 # < - Perl code to run before prompt.
10274 if ( $cmd =~ /^\</o ) {
10275 $which = 'pre-perl';
10279 # > - Perl code to run after prompt.
10280 elsif ( $cmd =~ /^\>/o ) {
10281 $which = 'post-perl';
10285 # { - first check for properly-balanced braces.
10286 elsif ( $cmd =~ /^\{/o ) {
10287 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
10289 "$cmd is now a debugger command\nuse ';$cmd' if you mean Perl code\n";
10292 # Properly balanced. Pre-prompt debugger actions.
10294 $which = 'pre-debugger';
10297 } ## end elsif ( $cmd =~ /^\{/o )
10299 # Did we find something that makes sense?
10301 print $OUT "Confused by command: $cmd\n";
10308 if ( $line =~ /^\s*\?\s*$/o ) {
10311 # Nothing there. Complain.
10312 print $OUT "No $which actions.\n";
10316 # List the actions in the selected list.
10317 print $OUT "$which commands:\n";
10318 foreach my $action (@$aref) {
10319 print $OUT "\t$cmd -- $action\n";
10322 } ## end if ( $line =~ /^\s*\?\s*$/o)
10324 # Might be a delete.
10326 if ( length($cmd) == 1 ) {
10327 if ( $line =~ /^\s*\*\s*$/o ) {
10329 # It's a delete. Get rid of the old actions in the
10332 print $OUT "All $cmd actions cleared.\n";
10336 # Replace all the actions. (This is a <, >, or {).
10337 @$aref = action($line);
10339 } ## end if ( length($cmd) == 1)
10340 elsif ( length($cmd) == 2 ) {
10342 # Add the action to the line. (This is a <<, >>, or {{).
10343 push @$aref, action($line);
10347 # <<<, >>>>, {{{{{{ ... something not a command.
10349 "Confused by strange length of $which command($cmd)...\n";
10351 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
10353 } ## end sub cmd_prepost
10357 Contains the C<at_exit> routine that the debugger uses to issue the
10358 C<Debugged program terminated ...> message after the program completes. See
10359 the C<END> block documentation for more details.
10366 "Debugged program terminated. Use 'q' to quit or 'R' to restart.";
10369 package DB; # Do not trace this 1; below!