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);
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";
874 *share = sub(\[$@%]) {};
878 # These variables control the execution of 'dumpvar.pl'.
893 # used to control die() reporting in diesignal()
896 use vars qw($CarpLevel);
899 # without threads, $filename is not defined until DB::DB is called
900 share($main::{'_<'.$filename}) if defined $filename;
902 # Command-line + PERLLIB:
903 # Save the contents of @INC before they are modified elsewhere.
906 # This was an attempt to clear out the previous values of various
907 # trapped errors. Apparently it didn't help. XXX More info needed!
908 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
910 # We set these variables to safe values. We don't want to blindly turn
911 # off warnings, because other packages may still want them.
912 $trace = $signal = $single = 0; # Uninitialized warning suppression
913 # (local $^W cannot help - other packages!).
915 # Default to not exiting when program finishes; print the return
916 # value when the 'r' command is used to return from a subroutine.
917 $inhibit_exit = $option{PrintRet} = 1;
919 use vars qw($trace_to_depth);
921 # Default to 1E9 so it won't be limited to a certain recursion depth.
922 $trace_to_depth = 1E9;
924 =head1 OPTION PROCESSING
926 The debugger's options are actually spread out over the debugger itself and
927 C<dumpvar.pl>; some of these are variables to be set, while others are
928 subs to be called with a value. To try to make this a little easier to
929 manage, the debugger uses a few data structures to define what options
930 are legal and how they are to be processed.
932 First, the C<@options> array defines the I<names> of all the options that
938 CommandSet HistFile HistSize
939 hashDepth arrayDepth dumpDepth
940 DumpDBFiles DumpPackages DumpReused
941 compactDump veryCompact quote
942 HighBit undefPrint globPrint
943 PrintRet UsageOnly frame
945 ReadLine NonStop LineInfo
946 maxTraceLen recallCommand ShellBang
947 pager tkRunning ornaments
948 signalLevel warnLevel dieLevel
949 inhibit_exit ImmediateStop bareStringify
950 CreateTTY RemotePort windowSize
954 @RememberOnROptions = qw(DollarCaretP);
958 Second, C<optionVars> lists the variables that each option uses to save its
963 use vars qw(%optionVars);
966 hashDepth => \$dumpvar::hashDepth,
967 arrayDepth => \$dumpvar::arrayDepth,
968 CommandSet => \$CommandSet,
969 DumpDBFiles => \$dumpvar::dumpDBFiles,
970 DumpPackages => \$dumpvar::dumpPackages,
971 DumpReused => \$dumpvar::dumpReused,
972 HighBit => \$dumpvar::quoteHighBit,
973 undefPrint => \$dumpvar::printUndef,
974 globPrint => \$dumpvar::globPrint,
975 UsageOnly => \$dumpvar::usageOnly,
976 CreateTTY => \$CreateTTY,
977 bareStringify => \$dumpvar::bareStringify,
979 AutoTrace => \$trace,
980 inhibit_exit => \$inhibit_exit,
981 maxTraceLen => \$maxtrace,
982 ImmediateStop => \$ImmediateStop,
983 RemotePort => \$remoteport,
984 windowSize => \$window,
985 HistFile => \$histfile,
986 HistSize => \$histsize,
991 Third, C<%optionAction> defines the subroutine to be called to process each
996 use vars qw(%optionAction);
999 compactDump => \&dumpvar::compactDump,
1000 veryCompact => \&dumpvar::veryCompact,
1001 quote => \&dumpvar::quote,
1004 ReadLine => \&ReadLine,
1005 NonStop => \&NonStop,
1006 LineInfo => \&LineInfo,
1007 recallCommand => \&recallCommand,
1008 ShellBang => \&shellBang,
1010 signalLevel => \&signalLevel,
1011 warnLevel => \&warnLevel,
1012 dieLevel => \&dieLevel,
1013 tkRunning => \&tkRunning,
1014 ornaments => \&ornaments,
1015 RemotePort => \&RemotePort,
1016 DollarCaretP => \&DollarCaretP,
1021 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1026 # Note that this list is not complete: several options not listed here
1027 # actually require that dumpvar.pl be loaded for them to work, but are
1028 # not in the table. A subsequent patch will correct this problem; for
1029 # the moment, we're just recommenting, and we are NOT going to change
1031 use vars qw(%optionRequire);
1034 compactDump => 'dumpvar.pl',
1035 veryCompact => 'dumpvar.pl',
1036 quote => 'dumpvar.pl',
1041 There are a number of initialization-related variables which can be set
1042 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1043 variable. These are:
1047 =item C<$rl> - readline control XXX needs more explanation
1049 =item C<$warnLevel> - whether or not debugger takes over warning handling
1051 =item C<$dieLevel> - whether or not debugger takes over die handling
1053 =item C<$signalLevel> - whether or not debugger takes over signal handling
1055 =item C<$pre> - preprompt actions (array reference)
1057 =item C<$post> - postprompt actions (array reference)
1061 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1063 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1069 # These guys may be defined in $ENV{PERL5DB} :
1070 $rl = 1 unless defined $rl;
1071 $warnLevel = 1 unless defined $warnLevel;
1072 $dieLevel = 1 unless defined $dieLevel;
1073 $signalLevel = 1 unless defined $signalLevel;
1074 $pre = [] unless defined $pre;
1075 $post = [] unless defined $post;
1076 $pretype = [] unless defined $pretype;
1077 $CreateTTY = 3 unless defined $CreateTTY;
1078 $CommandSet = '580' unless defined $CommandSet;
1083 share($signalLevel);
1093 The default C<die>, C<warn>, and C<signal> handlers are set up.
1097 warnLevel($warnLevel);
1098 dieLevel($dieLevel);
1099 signalLevel($signalLevel);
1103 The pager to be used is needed next. We try to get it from the
1104 environment first. If it's not defined there, we try to find it in
1105 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1106 then call the C<pager()> function to save the pager name.
1110 # This routine makes sure $pager is set up so that '|' can use it.
1113 # If PAGER is defined in the environment, use it.
1117 # If not, see if Config.pm defines it.
1118 : eval { require Config }
1119 && defined $Config::Config{pager}
1120 ? $Config::Config{pager}
1122 # If not, fall back to 'more'.
1125 unless defined $pager;
1129 We set up the command to be used to access the man pages, the command
1130 recall character (C<!> unless otherwise defined) and the shell escape
1131 character (C<!> unless otherwise defined). Yes, these do conflict, and
1132 neither works in the debugger at the moment.
1138 # Set up defaults for command recall and shell escape (note:
1139 # these currently don't work in linemode debugging).
1140 recallCommand("!") unless defined $prc;
1141 shellBang("!") unless defined $psh;
1145 We then set up the gigantic string containing the debugger help.
1146 We also set the limit on the number of arguments we'll display during a
1153 # If we didn't get a default for the length of eval/stack trace args,
1155 $maxtrace = 400 unless defined $maxtrace;
1157 =head2 SETTING UP THE DEBUGGER GREETING
1159 The debugger I<greeting> helps to inform the user how many debuggers are
1160 running, and whether the current debugger is the primary or a child.
1162 If we are the primary, we just hang onto our pid so we'll have it when
1163 or if we start a child debugger. If we are a child, we'll set things up
1164 so we'll have a unique greeting and so the parent will give us our own
1167 We save the current contents of the C<PERLDB_PIDS> environment variable
1168 because we mess around with it. We'll also need to hang onto it because
1169 we'll need it if we restart.
1171 Child debuggers make a label out of the current PID structure recorded in
1172 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1173 yet so the parent will give them one later via C<resetterm()>.
1177 # Save the current contents of the environment; we're about to
1178 # much with it. We'll need this if we have to restart.
1179 use vars qw($ini_pids);
1180 $ini_pids = $ENV{PERLDB_PIDS};
1182 use vars qw ($pids $term_pid);
1184 if ( defined $ENV{PERLDB_PIDS} ) {
1186 # We're a child. Make us a label out of the current PID structure
1187 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1188 # a term yet so the parent will give us one later via resetterm().
1190 my $env_pids = $ENV{PERLDB_PIDS};
1191 $pids = "[$env_pids]";
1193 # Unless we are on OpenVMS, all programs under the DCL shell run under
1196 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1200 $ENV{PERLDB_PIDS} .= "->$$";
1204 } ## end if (defined $ENV{PERLDB_PIDS...
1207 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1208 # child debugger, and mark us as the parent, so we'll know to set up
1209 # more TTY's is we have to.
1210 $ENV{PERLDB_PIDS} = "$$";
1215 use vars qw($pidprompt);
1218 # Sets up $emacs as a synonym for $slave_editor.
1219 our ($slave_editor);
1220 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1222 =head2 READING THE RC FILE
1224 The debugger will read a file of initialization options if supplied. If
1225 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1229 # As noted, this test really doesn't check accurately that the debugger
1230 # is running at a terminal or not.
1232 use vars qw($rcfile);
1234 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1235 # this is the wrong metric!
1236 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
1241 The debugger does a safety test of the file to be read. It must be owned
1242 either by the current user or root, and must only be writable by the owner.
1246 # This wraps a safety test around "do" to read and evaluate the init file.
1248 # This isn't really safe, because there's a race
1249 # between checking and opening. The solution is to
1250 # open and fstat the handle, but then you have to read and
1251 # eval the contents. But then the silly thing gets
1252 # your lexical scope, which is unfortunate at best.
1256 # Just exactly what part of the word "CORE::" don't you understand?
1257 local $SIG{__WARN__};
1258 local $SIG{__DIE__};
1260 unless ( is_safe_file($file) ) {
1261 CORE::warn <<EO_GRIPE;
1262 perldb: Must not source insecure rcfile $file.
1263 You or the superuser must be the owner, and it must not
1264 be writable by anyone but its owner.
1267 } ## end unless (is_safe_file($file...
1270 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1271 } ## end sub safe_do
1273 # This is the safety test itself.
1275 # Verifies that owner is either real user or superuser and that no
1276 # one but owner may write to it. This function is of limited use
1277 # when called on a path instead of upon a handle, because there are
1278 # no guarantees that filename (by dirent) whose file (by ino) is
1279 # eventually accessed is the same as the one tested.
1280 # Assumes that the file's existence is not in doubt.
1283 stat($path) || return; # mysteriously vaporized
1284 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1286 return 0 if $uid != 0 && $uid != $<;
1287 return 0 if $mode & 022;
1289 } ## end sub is_safe_file
1291 # If the rcfile (whichever one we decided was the right one to read)
1292 # exists, we safely do it.
1294 safe_do("./$rcfile");
1297 # If there isn't one here, try the user's home directory.
1298 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1299 safe_do("$ENV{HOME}/$rcfile");
1302 # Else try the login directory.
1303 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1304 safe_do("$ENV{LOGDIR}/$rcfile");
1307 # If the PERLDB_OPTS variable has options in it, parse those out next.
1308 if ( defined $ENV{PERLDB_OPTS} ) {
1309 parse_options( $ENV{PERLDB_OPTS} );
1314 The last thing we do during initialization is determine which subroutine is
1315 to be used to obtain a new terminal when a new debugger is started. Right now,
1316 the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
1321 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1322 # Works if you're running an xterm or xterm-like window, or you're on
1323 # OS/2, or on Mac OS X. This may need some expansion.
1325 if (not defined &get_fork_TTY) # only if no routine exists
1327 if ( defined $remoteport ) {
1328 # Expect an inetd-like server
1329 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1331 elsif (defined $ENV{TERM} # If we know what kind
1332 # of terminal this is,
1333 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1334 and defined $ENV{DISPLAY} # and what display it's on,
1337 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1339 elsif ( $ENV{TMUX} ) {
1340 *get_fork_TTY = \&tmux_get_fork_TTY;
1342 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1343 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1345 elsif ( $^O eq 'darwin' # If this is Mac OS X
1346 and defined $ENV{TERM_PROGRAM} # and we're running inside
1347 and $ENV{TERM_PROGRAM}
1348 eq 'Apple_Terminal' # Terminal.app
1351 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1353 } ## end if (not defined &get_fork_TTY...
1355 # untaint $^O, which may have been tainted by the last statement.
1356 # see bug [perl #24674]
1360 # Here begin the unreadable code. It needs fixing.
1362 =head2 RESTART PROCESSING
1364 This section handles the restart command. When the C<R> command is invoked, it
1365 tries to capture all of the state it can into environment variables, and
1366 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1367 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1368 the R command stuffed into the environment variables.
1370 PERLDB_RESTART - flag only, contains no restart data itself.
1371 PERLDB_HIST - command history, if it's available
1372 PERLDB_ON_LOAD - breakpoints set by the rc file
1373 PERLDB_POSTPONE - subs that have been loaded/not executed,
1375 PERLDB_VISITED - files that had breakpoints
1376 PERLDB_FILE_... - breakpoints for a file
1377 PERLDB_OPT - active options
1378 PERLDB_INC - the original @INC
1379 PERLDB_PRETYPE - preprompt debugger actions
1380 PERLDB_PRE - preprompt Perl code
1381 PERLDB_POST - post-prompt Perl code
1382 PERLDB_TYPEAHEAD - typeahead captured by readline()
1384 We chug through all these variables and plug the values saved in them
1385 back into the appropriate spots in the debugger.
1389 use vars qw(%postponed_file @typeahead);
1391 our (@hist, @truehist);
1393 sub _restore_shared_globals_after_restart
1395 @hist = get_list('PERLDB_HIST');
1396 %break_on_load = get_list("PERLDB_ON_LOAD");
1397 %postponed = get_list("PERLDB_POSTPONE");
1401 share(%break_on_load);
1405 sub _restore_breakpoints_and_actions {
1407 my @had_breakpoints = get_list("PERLDB_VISITED");
1409 for my $file_idx ( 0 .. $#had_breakpoints ) {
1410 my $filename = $had_breakpoints[$file_idx];
1411 my %pf = get_list("PERLDB_FILE_$file_idx");
1412 $postponed_file{ $filename } = \%pf if %pf;
1413 my @lines = sort {$a <=> $b} keys(%pf);
1414 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1415 for my $line_idx (0 .. $#lines) {
1416 _set_breakpoint_enabled_status(
1419 ($enabled_statuses[$line_idx] ? 1 : ''),
1427 sub _restore_options_after_restart
1429 my %options_map = get_list("PERLDB_OPT");
1431 while ( my ( $opt, $val ) = each %options_map ) {
1432 $val =~ s/[\\\']/\\$1/g;
1433 parse_options("$opt'$val'");
1439 sub _restore_globals_after_restart
1441 # restore original @INC
1442 @INC = get_list("PERLDB_INC");
1445 # return pre/postprompt actions and typeahead buffer
1446 $pretype = [ get_list("PERLDB_PRETYPE") ];
1447 $pre = [ get_list("PERLDB_PRE") ];
1448 $post = [ get_list("PERLDB_POST") ];
1449 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1455 if ( exists $ENV{PERLDB_RESTART} ) {
1457 # We're restarting, so we don't need the flag that says to restart anymore.
1458 delete $ENV{PERLDB_RESTART};
1461 _restore_shared_globals_after_restart();
1463 _restore_breakpoints_and_actions();
1466 _restore_options_after_restart();
1468 _restore_globals_after_restart();
1469 } ## end if (exists $ENV{PERLDB_RESTART...
1471 =head2 SETTING UP THE TERMINAL
1473 Now, we'll decide how the debugger is going to interact with the user.
1474 If there's no TTY, we set the debugger to run non-stop; there's not going
1475 to be anyone there to enter commands.
1479 use vars qw($notty $console $tty $LINEINFO);
1480 use vars qw($lineinfo $doccmd);
1484 # Local autoflush to avoid rt#116769,
1485 # as calling IO::File methods causes an unresolvable loop
1486 # that results in debugger failure.
1488 my $o = select($_[0]);
1500 If there is a TTY, we have to determine who it belongs to before we can
1501 proceed. If this is a slave editor or graphical debugger (denoted by
1502 the first command-line switch being '-emacs'), we shift this off and
1503 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1509 # Is Perl being run from a slave editor or graphical debugger?
1510 # If so, don't use readline, and set $slave_editor = 1.
1511 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1516 #require Term::ReadLine;
1520 We then determine what the console should be on various systems:
1524 =item * Cygwin - We use C<stdin> instead of a separate device.
1528 if ( $^O eq 'cygwin' ) {
1530 # /dev/tty is binary. use stdin for textmode
1534 =item * Unix - use F</dev/tty>.
1538 elsif ( -e "/dev/tty" ) {
1539 $console = "/dev/tty";
1542 =item * Windows or MSDOS - use C<con>.
1546 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1550 =item * VMS - use C<sys$command>.
1556 # everything else is ...
1557 $console = "sys\$command";
1564 Several other systems don't use a specific console. We C<undef $console>
1565 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1566 with a slave editor).
1570 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1572 # /dev/tty is binary. use stdin for textmode
1576 if ( $^O eq 'NetWare' ) {
1578 # /dev/tty is binary. use stdin for textmode
1582 # In OS/2, we need to use STDIN to get textmode too, even though
1583 # it pretty much looks like Unix otherwise.
1584 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1591 If there is a TTY hanging around from a parent, we use that as the console.
1595 $console = $tty if defined $tty;
1597 =head2 SOCKET HANDLING
1599 The debugger is capable of opening a socket and carrying out a debugging
1600 session over the socket.
1602 If C<RemotePort> was defined in the options, the debugger assumes that it
1603 should try to start a debugging session on that port. It builds the socket
1604 and then tries to connect the input and output filehandles to it.
1608 # Handle socket stuff.
1610 if ( defined $remoteport ) {
1612 # If RemotePort was defined in the options, connect input and output
1614 $IN = $OUT = connect_remoteport();
1615 } ## end if (defined $remoteport)
1619 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1620 this is probably a situation where multiple debuggers are running (for example,
1621 a backticked command that starts up another debugger). We create a new IN and
1622 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1630 # Two debuggers running (probably a system or a backtick that invokes
1631 # the debugger itself under the running one). create a new IN and OUT
1632 # filehandle, and do the necessary mojo to create a new tty if we
1633 # know how, and we can.
1634 create_IN_OUT(4) if $CreateTTY & 4;
1637 # If we have a console, check to see if there are separate ins and
1638 # outs to open. (They are assumed identical if not.)
1640 my ( $i, $o ) = split /,/, $console;
1641 $o = $i unless defined $o;
1643 # read/write on in, or just read, or read on STDIN.
1645 || open( IN, "<$i" )
1646 || open( IN, "<&STDIN" );
1648 # read/write/create/clobber out, or write/create/clobber out,
1649 # or merge with STDERR, or merge with STDOUT.
1651 || open( OUT, ">$o" )
1652 || open( OUT, ">&STDERR" )
1653 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1655 } ## end if ($console)
1656 elsif ( not defined $console ) {
1658 # No console. Open STDIN.
1659 open( IN, "<&STDIN" );
1661 # merge with STDERR, or with STDOUT.
1662 open( OUT, ">&STDERR" )
1663 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1664 $console = 'STDIN/OUT';
1665 } ## end elsif (not defined $console)
1667 # Keep copies of the filehandles so that when the pager runs, it
1668 # can close standard input without clobbering ours.
1669 if ($console or (not defined($console))) {
1673 } ## end elsif (from if(defined $remoteport))
1675 # Unbuffer DB::OUT. We need to see responses right away.
1678 # Line info goes to debugger output unless pointed elsewhere.
1679 # Pointing elsewhere makes it possible for slave editors to
1680 # keep track of file and position. We have both a filehandle
1681 # and a I/O description to keep track of.
1682 $LINEINFO = $OUT unless defined $LINEINFO;
1683 $lineinfo = $console unless defined $lineinfo;
1684 # share($LINEINFO); # <- unable to share globs
1689 To finish initialization, we show the debugger greeting,
1690 and then call the C<afterinit()> subroutine if there is one.
1694 # Show the debugger greeting.
1695 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1696 unless ($runnonstop) {
1699 if ( $term_pid eq '-1' ) {
1700 print $OUT "\nDaughter DB session started...\n";
1703 print $OUT "\nLoading DB routines from $header\n";
1706 $slave_editor ? "enabled" : "available", ".\n"
1709 "\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
1710 } ## end else [ if ($term_pid eq '-1')
1711 } ## end unless ($runnonstop)
1712 } ## end else [ if ($notty)
1714 # XXX This looks like a bug to me.
1715 # Why copy to @ARGS and then futz with @args?
1718 # Make sure backslashes before single quotes are stripped out, and
1719 # keep args unless they are numeric (XXX why?)
1720 # s/\'/\\\'/g; # removed while not justified understandably
1721 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1724 # If there was an afterinit() sub defined, call it. It will get
1725 # executed in our scope, so it can fiddle with debugger globals.
1726 if ( defined &afterinit ) { # May be defined in $rcfile
1730 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1731 use vars qw($I_m_init);
1735 ############################################################ Subroutines
1741 This gigantic subroutine is the heart of the debugger. Called before every
1742 statement, its job is to determine if a breakpoint has been reached, and
1743 stop if so; read commands from the user, parse them, and execute
1744 them, and then send execution off to the next statement.
1746 Note that the order in which the commands are processed is very important;
1747 some commands earlier in the loop will actually alter the C<$cmd> variable
1748 to create other commands to be executed later. This is all highly I<optimized>
1749 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1750 see what's happening in any given command.
1754 # $cmd cannot be an our() variable unfortunately (possible perl bug?).
1784 sub _DB__determine_if_we_should_break
1786 # if we have something here, see if we should break.
1787 # $stop is lexical and local to this block - $action on the other hand
1792 && _is_breakpoint_enabled($filename, $line)
1793 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1796 # Stop if the stop criterion says to just stop.
1797 if ( $stop eq '1' ) {
1801 # It's a conditional stop; eval it in the user's context and
1802 # see if we should stop. If so, remove the one-time sigil.
1804 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1805 # The &-call is here to ascertain the mutability of @_.
1807 # If the breakpoint is temporary, then delete its enabled status.
1808 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1809 _cancel_breakpoint_temp_enabled_status($filename, $line);
1812 } ## end if ($dbline{$line} && ...
1815 sub _DB__is_finished {
1816 if ($finished and $level <= 1) {
1825 sub _DB__read_next_cmd
1829 # We have a terminal, or can get one ...
1834 # ... and it belongs to this PID or we get one for this PID ...
1835 if ($term_pid != $$) {
1839 # ... and we got a line of command input ...
1840 $cmd = DB::readline(
1841 "$pidprompt $tid DB"
1844 . ( '>' x $level ) . " "
1847 return defined($cmd);
1850 sub _DB__trim_command_and_return_first_component {
1853 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1854 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1856 my ($verb, $args) = $cmd =~ m{\A(\S*)\s*(.*)}s;
1858 $obj->cmd_verb($verb);
1859 $obj->cmd_args($args);
1864 sub _DB__handle_f_command {
1867 if ($file = $obj->cmd_args) {
1868 # help for no arguments (old-style was return from sub).
1871 "The old f command is now the r command.\n"; # hint
1872 print $OUT "The new f command switches filenames.\n";
1874 } ## end if (!$file)
1876 # if not in magic file list, try a close match.
1877 if ( !defined $main::{ '_<' . $file } ) {
1878 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
1880 $try = substr( $try, 2 );
1881 print $OUT "Choosing $try matching '$file':\n";
1884 } ## end if (($try) = grep(m#^_<.*$file#...
1885 } ## end if (!defined $main::{ ...
1887 # If not successfully switched now, we failed.
1888 if ( !defined $main::{ '_<' . $file } ) {
1889 print $OUT "No file matching '$file' is loaded.\n";
1893 # We switched, so switch the debugger internals around.
1894 elsif ( $file ne $filename ) {
1895 *dbline = $main::{ '_<' . $file };
1900 } ## end elsif ($file ne $filename)
1902 # We didn't switch; say we didn't.
1904 print $OUT "Already in $file.\n";
1912 sub _DB__handle_dot_command {
1916 if ($obj->_is_full('.')) {
1917 $incr = -1; # stay at current line
1919 # Reset everything to the old location.
1921 $filename = $filename_ini;
1922 *dbline = $main::{ '_<' . $filename };
1926 print_lineinfo($obj->position());
1933 sub _DB__handle_y_command {
1936 if (my ($match_level, $match_vars)
1937 = $obj->cmd_args =~ /\A(?:(\d*)\s*(.*))?\z/) {
1939 # See if we've got the necessary support.
1940 if (!eval { require PadWalker; PadWalker->VERSION(0.08) }) {
1944 ? "PadWalker module not found - please install\n"
1950 # Load up dumpvar if we don't have it. If we can, that is.
1951 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
1952 defined &main::dumpvar
1953 or print $OUT "dumpvar.pl not available.\n"
1956 # Got all the modules we need. Find them and print them.
1957 my @vars = split( ' ', $match_vars || '' );
1960 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 1 ) };
1962 # Oops. Can't find it.
1969 # Show the desired vars with dumplex().
1970 my $savout = select($OUT);
1972 # Have dumplex dump the lexicals.
1973 foreach my $key (sort keys %$h) {
1974 dumpvar::dumplex( $key, $h->{$key},
1975 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
1983 sub _DB__handle_c_command {
1986 my $i = $obj->cmd_args;
1988 if ($i =~ m#\A[\w:]*\z#) {
1990 # Hey, show's over. The debugged program finished
1991 # executing already.
1992 next CMD if _DB__is_finished();
1994 # Capture the place to put a one-time break.
1997 # Probably not needed, since we finish an interactive
1998 # sub-session anyway...
1999 # local $filename = $filename;
2000 # local *dbline = *dbline; # XXX Would this work?!
2002 # The above question wonders if localizing the alias
2003 # to the magic array works or not. Since it's commented
2004 # out, we'll just leave that to speculation for now.
2006 # If the "subname" isn't all digits, we'll assume it
2007 # is a subroutine name, and try to find it.
2008 if ( $subname =~ /\D/ ) { # subroutine name
2009 # Qualify it to the current package unless it's
2010 # already qualified.
2011 $subname = $package . "::" . $subname
2012 unless $subname =~ /::/;
2014 # find_sub will return "file:line_number" corresponding
2015 # to where the subroutine is defined; we call find_sub,
2016 # break up the return value, and assign it in one
2018 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2020 # Force the line number to be numeric.
2023 # If we got a line number, we found the sub.
2026 # Switch all the debugger's internals around so
2027 # we're actually working with that file.
2029 *dbline = $main::{ '_<' . $filename };
2031 # Mark that there's a breakpoint in this file.
2032 $had_breakpoints{$filename} |= 1;
2034 # Scan forward to the first executable line
2035 # after the 'sub whatever' line.
2038 while ($dbline[$_line_num] == 0 && $_line_num< $max)
2045 # We didn't find a sub by that name.
2047 print $OUT "Subroutine $subname not found.\n";
2050 } ## end if ($subname =~ /\D/)
2052 # At this point, either the subname was all digits (an
2053 # absolute line-break request) or we've scanned through
2054 # the code following the definition of the sub, looking
2055 # for an executable, which we may or may not have found.
2057 # If $i (which we set $subname from) is non-zero, we
2058 # got a request to break at some line somewhere. On
2059 # one hand, if there wasn't any real subroutine name
2060 # involved, this will be a request to break in the current
2061 # file at the specified line, so we have to check to make
2062 # sure that the line specified really is breakable.
2064 # On the other hand, if there was a subname supplied, the
2065 # preceding block has moved us to the proper file and
2066 # location within that file, and then scanned forward
2067 # looking for the next executable line. We have to make
2068 # sure that one was found.
2070 # On the gripping hand, we can't do anything unless the
2071 # current value of $i points to a valid breakable line.
2076 if ( $dbline[$i] == 0 ) {
2077 print $OUT "Line $i not breakable.\n";
2081 # Yes. Set up the one-time-break sigil.
2082 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2083 _enable_breakpoint_temp_enabled_status($filename, $i);
2086 # Turn off stack tracing from here up.
2087 for my $j (0 .. $stack_depth) {
2096 sub _DB__handle_forward_slash_command {
2099 # The pattern as a string.
2100 use vars qw($inpat);
2102 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2104 # Remove the final slash.
2105 $inpat =~ s:([^\\])/$:$1:;
2107 # If the pattern isn't null ...
2108 if ( $inpat ne "" ) {
2110 # Turn off warn and die processing for a bit.
2111 local $SIG{__DIE__};
2112 local $SIG{__WARN__};
2114 # Create the pattern.
2115 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2118 # Oops. Bad pattern. No biscuit.
2119 # Print the eval error and go back for more
2125 } ## end if ($inpat ne "")
2127 # Set up to stop on wrap-around.
2130 # Don't move off the current line.
2133 my $pat = $obj->pat;
2135 # Done in eval so nothing breaks if the pattern
2136 # does something weird.
2141 # Move ahead one line.
2144 # Wrap if we pass the last line.
2145 if ($start > $max) {
2149 # Stop if we have gotten back to this line again,
2150 last if ($start == $end);
2152 # A hit! (Note, though, that we are doing
2153 # case-insensitive matching. Maybe a qr//
2154 # expression would be better, so the user could
2155 # do case-sensitive matching if desired.
2156 if ($dbline[$start] =~ m/$pat/i) {
2157 if ($slave_editor) {
2158 # Handle proper escaping in the slave.
2159 print {$OUT} "\032\032$filename:$start:0\n";
2162 # Just print the line normally.
2163 print {$OUT} "$start:\t",$dbline[$start],"\n";
2165 # And quit since we found something.
2175 # If we wrapped, there never was a match.
2176 if ( $start == $end ) {
2177 print {$OUT} "/$pat/: not found\n";
2185 sub _DB__handle_question_mark_command {
2188 # ? - backward pattern search.
2189 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2191 # Get the pattern, remove trailing question mark.
2192 $inpat =~ s:([^\\])\?$:$1:;
2194 # If we've got one ...
2195 if ( $inpat ne "" ) {
2197 # Turn off die & warn handlers.
2198 local $SIG{__DIE__};
2199 local $SIG{__WARN__};
2200 eval '$inpat =~ m' . "\a$inpat\a";
2204 # Ouch. Not good. Print the error.
2209 } ## end if ($inpat ne "")
2211 # Where we are now is where to stop after wraparound.
2214 # Don't move away from this line.
2217 my $pat = $obj->pat;
2218 # Search inside the eval to prevent pattern badness
2226 # Wrap if we pass the first line.
2228 $start = $max if ($start <= 0);
2230 # Quit if we get back where we started,
2231 last if ($start == $end);
2234 if ($dbline[$start] =~ m/$pat/i) {
2235 if ($slave_editor) {
2236 # Yep, follow slave editor requirements.
2237 print $OUT "\032\032$filename:$start:0\n";
2240 # Yep, just print normally.
2241 print $OUT "$start:\t",$dbline[$start],"\n";
2250 # Say we failed if the loop never found anything,
2251 if ( $start == $end ) {
2252 print {$OUT} "?$pat?: not found\n";
2260 sub _DB__handle_restart_and_rerun_commands {
2263 my $cmd_cmd = $obj->cmd_verb;
2264 my $cmd_params = $obj->cmd_args;
2265 # R - restart execution.
2266 # rerun - controlled restart execution.
2267 if ($cmd_cmd eq 'rerun' or $cmd_params eq '') {
2269 # Change directory to the initial current working directory on
2270 # the script startup, so if the debugged program changed the
2271 # directory, then we will still be able to find the path to the
2272 # the program. (perl 5 RT #121509 ).
2273 chdir ($_initial_cwd);
2275 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
2277 # Close all non-system fds for a clean restart. A more
2278 # correct method would be to close all fds that were not
2279 # open when the process started, but this seems to be
2280 # hard. See "debugger 'R'estart and open database
2281 # connections" on p5p.
2283 my $max_fd = 1024; # default if POSIX can't be loaded
2284 if (eval { require POSIX }) {
2285 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
2288 if (defined $max_fd) {
2289 foreach ($^F+1 .. $max_fd-1) {
2290 next unless open FD_TO_CLOSE, "<&=$_";
2295 # And run Perl again. We use exec() to keep the
2296 # PID stable (and that way $ini_pids is still valid).
2297 exec(@args) or print {$OUT} "exec failed: $!\n";
2305 sub _DB__handle_run_command_in_pager_command {
2308 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
2309 if ( $pager =~ /^\|/ ) {
2311 # Default pager is into a pipe. Redirect I/O.
2312 open( SAVEOUT, ">&STDOUT" )
2313 || _db_warn("Can't save STDOUT");
2314 open( STDOUT, ">&OUT" )
2315 || _db_warn("Can't redirect STDOUT");
2316 } ## end if ($pager =~ /^\|/)
2319 # Not into a pipe. STDOUT is safe.
2320 open( SAVEOUT, ">&OUT" ) || _db_warn("Can't save DB::OUT");
2323 # Fix up environment to record we have less if so.
2326 unless ( $obj->piped(scalar ( open( OUT, $pager ) ) ) ) {
2328 # Couldn't open pipe to pager.
2329 _db_warn("Can't pipe output to '$pager'");
2330 if ( $pager =~ /^\|/ ) {
2332 # Redirect I/O back again.
2333 open( OUT, ">&STDOUT" ) # XXX: lost message
2334 || _db_warn("Can't restore DB::OUT");
2335 open( STDOUT, ">&SAVEOUT" )
2336 || _db_warn("Can't restore STDOUT");
2338 } ## end if ($pager =~ /^\|/)
2341 # Redirect I/O. STDOUT already safe.
2342 open( OUT, ">&STDOUT" ) # XXX: lost message
2343 || _db_warn("Can't restore DB::OUT");
2346 } ## end unless ($piped = open(OUT,...
2348 # Set up broken-pipe handler if necessary.
2349 $SIG{PIPE} = \&DB::catch
2351 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
2354 # Save current filehandle, and put it back.
2355 $obj->selected(scalar( select(OUT) ));
2356 # Don't put it back if pager was a pipe.
2357 if ($cmd !~ /\A\|\|/)
2359 select($obj->selected());
2363 # Trim off the pipe symbols and run the command now.
2364 $cmd =~ s#\A\|+\s*##;
2371 sub _DB__handle_m_command {
2374 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2379 # m expr - set up DB::eval to do the work
2380 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2381 $onetimeDump = 'methods'; # method output gets used there
2387 sub _DB__at_end_of_every_command {
2390 # At the end of every command:
2393 # Unhook the pipe mechanism now.
2394 if ( $pager =~ /^\|/ ) {
2396 # No error from the child.
2399 # we cannot warn here: the handle is missing --tchrist
2400 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
2402 # most of the $? crud was coping with broken cshisms
2403 # $? is explicitly set to 0, so this never runs.
2405 print SAVEOUT "Pager '$pager' failed: ";
2407 print SAVEOUT "shell returned -1\n";
2410 print SAVEOUT ( $? & 127 )
2411 ? " (SIG#" . ( $? & 127 ) . ")"
2412 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
2415 print SAVEOUT "status ", ( $? >> 8 ), "\n";
2419 # Reopen filehandle for our output (if we can) and
2420 # restore STDOUT (if we can).
2421 open( OUT, ">&STDOUT" ) || _db_warn("Can't restore DB::OUT");
2422 open( STDOUT, ">&SAVEOUT" )
2423 || _db_warn("Can't restore STDOUT");
2425 # Turn off pipe exception handler if necessary.
2426 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
2428 # Will stop ignoring SIGPIPE if done like nohup(1)
2429 # does SIGINT but Perl doesn't give us a choice.
2430 } ## end if ($pager =~ /^\|/)
2433 # Non-piped "pager". Just restore STDOUT.
2434 open( OUT, ">&SAVEOUT" ) || _db_warn("Can't restore DB::OUT");
2437 # Let Readline know about the new filehandles.
2438 reset_IN_OUT( \*IN, \*OUT );
2440 # Close filehandle pager was using, restore the normal one
2444 if ($obj->selected() ne "") {
2445 select($obj->selected);
2451 } ## end if ($piped)
2456 sub _DB__handle_watch_expressions
2460 if ( $DB::trace & 2 ) {
2461 for my $n (0 .. $#DB::to_watch) {
2462 $DB::evalarg = $DB::to_watch[$n];
2463 local $DB::onetimeDump; # Tell DB::eval() to not output results
2465 # Fix context DB::eval() wants to return an array, but
2466 # we need a scalar here.
2467 my ($val) = join( "', '", DB::eval(@_) );
2468 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
2471 if ( $val ne $DB::old_watch[$n] ) {
2473 # Yep! Show the difference, and fake an interrupt.
2475 print {$DB::OUT} <<EOP;
2476 Watchpoint $n:\t$DB::to_watch[$n] changed:
2477 old value:\t$DB::old_watch[$n]
2480 $DB::old_watch[$n] = $val;
2481 } ## end if ($val ne $old_watch...
2482 } ## end for my $n (0 ..
2483 } ## end if ($trace & 2)
2490 # 'v' is the value (i.e: method name or subroutine ref).
2491 # 's' is subroutine.
2494 '-' => { t => 'm', v => '_handle_dash_command', },
2495 '.' => { t => 's', v => \&_DB__handle_dot_command, },
2496 '=' => { t => 'm', v => '_handle_equal_sign_command', },
2497 'H' => { t => 'm', v => '_handle_H_command', },
2498 'S' => { t => 'm', v => '_handle_S_command', },
2499 'T' => { t => 'm', v => '_handle_T_command', },
2500 'W' => { t => 'm', v => '_handle_W_command', },
2501 'c' => { t => 's', v => \&_DB__handle_c_command, },
2502 'f' => { t => 's', v => \&_DB__handle_f_command, },
2503 'm' => { t => 's', v => \&_DB__handle_m_command, },
2504 'n' => { t => 'm', v => '_handle_n_command', },
2505 'p' => { t => 'm', v => '_handle_p_command', },
2506 'q' => { t => 'm', v => '_handle_q_command', },
2507 'r' => { t => 'm', v => '_handle_r_command', },
2508 's' => { t => 'm', v => '_handle_s_command', },
2509 'save' => { t => 'm', v => '_handle_save_command', },
2510 'source' => { t => 'm', v => '_handle_source_command', },
2511 't' => { t => 'm', v => '_handle_t_command', },
2512 'w' => { t => 'm', v => '_handle_w_command', },
2513 'x' => { t => 'm', v => '_handle_x_command', },
2514 'y' => { t => 's', v => \&_DB__handle_y_command, },
2515 (map { $_ => { t => 'm', v => '_handle_V_command_and_X_command', }, }
2517 (map { $_ => { t => 'm', v => '_handle_enable_disable_commands', }, }
2518 qw(enable disable)),
2520 { t => 's', v => \&_DB__handle_restart_and_rerun_commands, },
2522 (map { $_ => {t => 'm', v => '_handle_cmd_wrapper_commands' }, }
2523 qw(a A b B e E h i l L M o O v w W)),
2528 # lock the debugger and get the thread id for the prompt
2532 my ($prefix, $after, $infix);
2538 if ($ENV{PERL5DB_THREADED}) {
2539 $tid = eval { "[".threads->tid."]" };
2545 my $obj = DB::Obj->new(
2547 position => \$position,
2550 explicit_stop => \$explicit_stop,
2552 cmd_args => \$cmd_args,
2553 cmd_verb => \$cmd_verb,
2556 selected => \$selected,
2560 $obj->_DB_on_init__initialize_globals(@_);
2562 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
2563 # The code being debugged may have altered them.
2566 # Since DB::DB gets called after every line, we can use caller() to
2567 # figure out where we last were executing. Sneaky, eh? This works because
2568 # caller is returning all the extra information when called from the
2570 local ( $package, $filename, $line ) = caller;
2571 $filename_ini = $filename;
2573 # set up the context for DB::eval, so it can properly execute
2574 # code on behalf of the user. We add the package in so that the
2575 # code is eval'ed in the proper package (not in the debugger!).
2576 local $usercontext = _calc_usercontext($package);
2578 # Create an alias to the active file magical array to simplify
2580 local (*dbline) = $main::{ '_<' . $filename };
2582 # Last line in the program.
2585 # The &-call is here to ascertain the mutability of @_.
2586 &_DB__determine_if_we_should_break;
2588 # Preserve the current stop-or-not, and see if any of the W
2589 # (watch expressions) has changed.
2590 my $was_signal = $signal;
2592 # If we have any watch expressions ...
2593 _DB__handle_watch_expressions($obj);
2595 =head2 C<watchfunction()>
2597 C<watchfunction()> is a function that can be defined by the user; it is a
2598 function which will be run on each entry to C<DB::DB>; it gets the
2599 current package, filename, and line as its parameters.
2601 The watchfunction can do anything it likes; it is executing in the
2602 debugger's context, so it has access to all of the debugger's internal
2603 data structures and functions.
2605 C<watchfunction()> can control the debugger's actions. Any of the following
2606 will cause the debugger to return control to the user's program after
2607 C<watchfunction()> executes:
2613 Returning a false value from the C<watchfunction()> itself.
2617 Altering C<$single> to a false value.
2621 Altering C<$signal> to a false value.
2625 Turning off the C<4> bit in C<$trace> (this also disables the
2626 check for C<watchfunction()>. This can be done with
2634 # If there's a user-defined DB::watchfunction, call it with the
2635 # current package, filename, and line. The function executes in
2637 if ( $trace & 4 ) { # User-installed watch
2639 if watchfunction( $package, $filename, $line )
2642 and not( $trace & ~4 );
2643 } ## end if ($trace & 4)
2645 # Pick up any alteration to $signal in the watchfunction, and
2646 # turn off the signal now.
2647 $was_signal = $signal;
2650 =head2 GETTING READY TO EXECUTE COMMANDS
2652 The debugger decides to take control if single-step mode is on, the
2653 C<t> command was entered, or the user generated a signal. If the program
2654 has fallen off the end, we set things up so that entering further commands
2655 won't cause trouble, and we say that the program is over.
2659 # Make sure that we always print if asked for explicitly regardless
2660 # of $trace_to_depth .
2661 $explicit_stop = ($single || $was_signal);
2663 # Check to see if we should grab control ($single true,
2664 # trace set appropriately, or we got a signal).
2665 if ( $explicit_stop || ( $trace & 1 ) ) {
2666 $obj->_DB__grab_control(@_);
2667 } ## end if ($single || ($trace...
2671 If there's an action to be executed for the line we stopped at, execute it.
2672 If there are any preprompt actions, execute those as well.
2676 # If there's an action, do it now.
2679 # The &-call is here to ascertain the mutability of @_.
2683 # Are we nested another level (e.g., did we evaluate a function
2684 # that had a breakpoint in it at the debugger prompt)?
2685 if ( $single || $was_signal ) {
2687 # Yes, go down a level.
2688 local $level = $level + 1;
2690 # Do any pre-prompt actions.
2691 foreach $evalarg (@$pre) {
2692 # The &-call is here to ascertain the mutability of @_.
2696 # Complain about too much recursion if we passed the limit.
2698 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2701 # The line we're currently on. Set $incr to -1 to stay here
2702 # until we get a command that tells us to advance.
2704 $incr = -1; # for backward motion.
2706 # Tack preprompt debugger actions ahead of any actual input.
2707 @typeahead = ( @$pretype, @typeahead );
2709 =head2 WHERE ARE WE?
2711 XXX Relocate this section?
2713 The debugger normally shows the line corresponding to the current line of
2714 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2715 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2717 C<$incr> controls by how many lines the I<current> line should move forward
2718 after a command is executed. If set to -1, this indicates that the I<current>
2719 line shouldn't change.
2721 C<$start> is the I<current> line. It is used for things like knowing where to
2722 move forwards or backwards from when doing an C<L> or C<-> command.
2724 C<$max> tells the debugger where the last line of the current file is. It's
2725 used to terminate loops most often.
2727 =head2 THE COMMAND LOOP
2729 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2736 The outer part of the loop, starting at the C<CMD> label. This loop
2737 reads a command and then executes it.
2741 The inner part of the loop, starting at the C<PIPE> label. This part
2742 is wholly contained inside the C<CMD> block and only executes a command.
2743 Used to handle commands running inside a pager.
2747 So why have two labels to restart the loop? Because sometimes, it's easier to
2748 have a command I<generate> another command and then re-execute the loop to do
2749 the new command. This is faster, but perhaps a bit more convoluted.
2753 # The big command dispatch loop. It keeps running until the
2754 # user yields up control again.
2756 # If we have a terminal for input, and we get something back
2757 # from readline(), keep on processing.
2760 while (_DB__read_next_cmd($tid))
2764 # ... try to execute the input as debugger commands.
2766 # Don't stop running.
2769 # No signal is active.
2772 # Handle continued commands (ending with \):
2773 if ($cmd =~ s/\\\z/\n/) {
2774 $cmd .= DB::readline(" cont: ");
2778 =head4 The null command
2780 A newline entered by itself means I<re-execute the last command>. We grab the
2781 command out of C<$laststep> (where it was recorded previously), and copy it
2782 back into C<$cmd> to be executed below. If there wasn't any previous command,
2783 we'll do nothing below (no command will match). If there was, we also save it
2784 in the command history and fall through to allow the command parsing to pick
2789 # Empty input means repeat the last command.
2793 chomp($cmd); # get rid of the annoying extra newline
2794 if (length($cmd) >= 2) {
2795 push( @hist, $cmd );
2797 push( @truehist, $cmd );
2801 # This is a restart point for commands that didn't arrive
2802 # via direct user input. It allows us to 'redo PIPE' to
2803 # re-execute command processing without reading a new command.
2805 _DB__trim_command_and_return_first_component($obj);
2807 =head3 COMMAND ALIASES
2809 The debugger can create aliases for commands (these are stored in the
2810 C<%alias> hash). Before a command is executed, the command loop looks it up
2811 in the alias hash and substitutes the contents of the alias for the command,
2812 completely replacing it.
2816 # See if there's an alias for the command, and set it up if so.
2817 if ( $alias{$cmd_verb} ) {
2819 # Squelch signal handling; we want to keep control here
2820 # if something goes loco during the alias eval.
2821 local $SIG{__DIE__};
2822 local $SIG{__WARN__};
2824 # This is a command, so we eval it in the DEBUGGER's
2825 # scope! Otherwise, we can't see the special debugger
2826 # variables, or get to the debugger's subs. (Well, we
2827 # _could_, but why make it even more complicated?)
2828 eval "\$cmd =~ $alias{$cmd_verb}";
2831 print $OUT "Couldn't evaluate '$cmd_verb' alias: $@";
2834 _DB__trim_command_and_return_first_component($obj);
2835 } ## end if ($alias{$cmd_verb})
2837 =head3 MAIN-LINE COMMANDS
2839 All of these commands work up to and after the program being debugged has
2844 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2845 try to execute further, cleaning any restart-related stuff out of the
2846 environment, and executing with the last value of C<$?>.
2850 # All of these commands were remapped in perl 5.8.0;
2851 # we send them off to the secondary dispatcher (see below).
2852 $obj->_handle_special_char_cmd_wrapper_commands;
2853 _DB__trim_command_and_return_first_component($obj);
2855 if (my $cmd_rec = $cmd_lookup{$cmd_verb}) {
2856 my $type = $cmd_rec->{t};
2857 my $val = $cmd_rec->{v};
2861 elsif ($type eq 's') {
2866 =head4 C<t> - trace [n]
2868 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2869 If level is specified, set C<$trace_to_depth>.
2871 =head4 C<S> - list subroutines matching/not matching a pattern
2873 Walks through C<%sub>, checking to see whether or not to print the name.
2875 =head4 C<X> - list variables in current package
2877 Since the C<V> command actually processes this, just change this to the
2878 appropriate C<V> command and fall through.
2880 =head4 C<V> - list variables
2882 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2884 =head4 C<x> - evaluate and print an expression
2886 Hands the expression off to C<DB::eval>, setting it up to print the value
2887 via C<dumpvar.pl> instead of just printing it directly.
2889 =head4 C<m> - print methods
2891 Just uses C<DB::methods> to determine what methods are available.
2893 =head4 C<f> - switch files
2895 Switch to a different filename.
2897 =head4 C<.> - return to last-executed line.
2899 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2900 and then we look up the line in the magical C<%dbline> hash.
2902 =head4 C<-> - back one window
2904 We change C<$start> to be one window back; if we go back past the first line,
2905 we set it to be the first line. We ser C<$incr> to put us back at the
2906 currently-executing line, and then put a C<l $start +> (list one window from
2907 C<$start>) in C<$cmd> to be executed later.
2909 =head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
2911 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2912 problems, most notably that the default case of several commands destroying
2913 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2914 retain the old commands for those who were used to using them or who preferred
2915 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2916 deal with them instead of processing them in-line.
2918 =head4 C<y> - List lexicals in higher scope
2920 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2921 above the current one and then displays then using C<dumpvar.pl>.
2923 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2925 All of the commands below this point don't work after the program being
2926 debugged has ended. All of them check to see if the program has ended; this
2927 allows the commands to be relocated without worrying about a 'line of
2928 demarcation' above which commands can be entered anytime, and below which
2931 =head4 C<n> - single step, but don't trace down into subs
2933 Done by setting C<$single> to 2, which forces subs to execute straight through
2934 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2935 so a null command knows what to re-execute.
2937 =head4 C<s> - single-step, entering subs
2939 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2940 subs. Also saves C<s> as C<$lastcmd>.
2942 =head4 C<c> - run continuously, setting an optional breakpoint
2944 Most of the code for this command is taken up with locating the optional
2945 breakpoint, which is either a subroutine name or a line number. We set
2946 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2947 in this and all call levels above this one.
2949 =head4 C<r> - return from a subroutine
2951 For C<r> to work properly, the debugger has to stop execution again
2952 immediately after the return is executed. This is done by forcing
2953 single-stepping to be on in the call level above the current one. If
2954 we are printing return values when a C<r> is executed, set C<$doret>
2955 appropriately, and force us out of the command loop.
2957 =head4 C<T> - stack trace
2959 Just calls C<DB::print_trace>.
2961 =head4 C<w> - List window around current line.
2963 Just calls C<DB::cmd_w>.
2965 =head4 C<W> - watch-expression processing.
2967 Just calls C<DB::cmd_W>.
2969 =head4 C</> - search forward for a string in the source
2971 We take the argument and treat it as a pattern. If it turns out to be a
2972 bad one, we return the error we got from trying to C<eval> it and exit.
2973 If not, we create some code to do the search and C<eval> it so it can't
2978 _DB__handle_forward_slash_command($obj);
2980 =head4 C<?> - search backward for a string in the source
2982 Same as for C</>, except the loop runs backwards.
2986 _DB__handle_question_mark_command($obj);
2988 =head4 C<$rc> - Recall command
2990 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2991 that the terminal supports history). It finds the command required, puts it
2992 into C<$cmd>, and redoes the loop to execute it.
2996 # $rc - recall command.
2997 $obj->_handle_rc_recall_command;
2999 =head4 C<$sh$sh> - C<system()> command
3001 Calls the C<_db_system()> to handle the command. This keeps the C<STDIN> and
3002 C<STDOUT> from getting messed up.
3006 $obj->_handle_sh_command;
3008 =head4 C<$rc I<pattern> $rc> - Search command history
3010 Another command to manipulate C<@hist>: this one searches it with a pattern.
3011 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
3015 $obj->_handle_rc_search_history_command;
3017 =head4 C<$sh> - Invoke a shell
3019 Uses C<_db_system()> to invoke a shell.
3023 =head4 C<$sh I<command>> - Force execution of a command in a shell
3025 Like the above, but the command is passed to the shell. Again, we use
3026 C<_db_system()> to avoid problems with C<STDIN> and C<STDOUT>.
3028 =head4 C<H> - display commands in history
3030 Prints the contents of C<@hist> (if any).
3032 =head4 C<man, doc, perldoc> - look up documentation
3034 Just calls C<runman()> to print the appropriate document.
3038 $obj->_handle_doc_command;
3042 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3043 the bottom of the loop.
3045 =head4 C<=> - define command alias
3047 Manipulates C<%alias> to add or list command aliases.
3049 =head4 C<source> - read commands from a file.
3051 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3054 =head4 C<enable> C<disable> - enable or disable breakpoints
3056 This enables or disables breakpoints.
3058 =head4 C<save> - send current history to a file
3060 Takes the complete history, (not the shrunken version you see with C<H>),
3061 and saves it to the given filename, so it can be replayed using C<source>.
3063 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3065 =head4 C<R> - restart
3067 Restart the debugger session.
3069 =head4 C<rerun> - rerun the current session
3071 Return to any given position in the B<true>-history list
3073 =head4 C<|, ||> - pipe output through the pager.
3075 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3076 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3077 pipe to the pager (restoring the output filehandles if this fails). If this
3078 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3079 set C<$signal>, sending us back into the debugger.
3081 We then trim off the pipe symbols and C<redo> the command loop at the
3082 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3087 # || - run command in the pager, with output to DB::OUT.
3088 _DB__handle_run_command_in_pager_command($obj);
3090 =head3 END OF COMMAND PARSING
3092 Anything left in C<$cmd> at this point is a Perl expression that we want to
3093 evaluate. We'll always evaluate in the user's context, and fully qualify
3094 any variables we might want to address in the C<DB> package.
3100 # trace an expression
3101 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3103 # Make sure the flag that says "the debugger's running" is
3104 # still on, to make sure we get control again.
3105 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3107 # Run *our* eval that executes in the caller's context.
3108 # The &-call is here to ascertain the mutability of @_.
3111 # Turn off the one-time-dump stuff now.
3113 $onetimeDump = undef;
3114 $onetimedumpDepth = undef;
3116 elsif ( $term_pid == $$ ) {
3117 eval { # May run under miniperl, when not available...
3122 # XXX If this is the master pid, print a newline.
3125 } ## end while (($term || &setterm...
3127 =head3 POST-COMMAND PROCESSING
3129 After each command, we check to see if the command output was piped anywhere.
3130 If so, we go through the necessary code to unhook the pipe and go back to
3131 our standard filehandles for input and output.
3136 _DB__at_end_of_every_command($obj);
3139 =head3 COMMAND LOOP TERMINATION
3141 When commands have finished executing, we come here. If the user closed the
3142 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3143 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3144 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3145 The interpreter will then execute the next line and then return control to us
3150 # No more commands? Quit.
3151 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
3153 # Evaluate post-prompt commands.
3154 foreach $evalarg (@$post) {
3155 # The &-call is here to ascertain the mutability of @_.
3158 } # if ($single || $signal)
3160 # Put the user's globals back where you found them.
3161 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3165 # Because DB::Obj is used above,
3167 # my $obj = DB::Obj->new(
3169 # The following package declaration must come before that,
3170 # or else runtime errors will occur with
3172 # PERLDB_OPTS="autotrace nonstop"
3182 my $self = bless {}, $class;
3190 my ($self, $args) = @_;
3192 %{$self} = (%$self, %$args);
3199 foreach my $slot_name (qw(
3200 after explicit_stop infix pat piped position prefix selected cmd_verb
3203 my $slot = $slot_name;
3208 ${ $self->{$slot} } = shift;
3211 return ${ $self->{$slot} };
3214 *{"append_to_$slot"} = sub {
3218 return $self->$slot($self->$slot . $s);
3223 sub _DB_on_init__initialize_globals
3227 # Check for whether we should be running continuously or not.
3228 # _After_ the perl program is compiled, $single is set to 1:
3229 if ( $single and not $second_time++ ) {
3231 # Options say run non-stop. Run until we get an interrupt.
3232 if ($runnonstop) { # Disable until signal
3233 # If there's any call stack in place, turn off single
3234 # stepping into subs throughout the stack.
3235 for my $i (0 .. $stack_depth) {
3239 # And we are now no longer in single-step mode.
3242 # If we simply returned at this point, we wouldn't get
3243 # the trace info. Fall on through.
3245 } ## end if ($runnonstop)
3247 elsif ($ImmediateStop) {
3249 # We are supposed to stop here; XXX probably a break.
3250 $ImmediateStop = 0; # We've processed it; turn it off
3251 $signal = 1; # Simulate an interrupt to force
3252 # us into the command loop
3254 } ## end if ($single and not $second_time...
3256 # If we're in single-step mode, or an interrupt (real or fake)
3257 # has occurred, turn off non-stop mode.
3258 $runnonstop = 0 if $single or $signal;
3263 sub _my_print_lineinfo
3265 my ($self, $i, $incr_pos) = @_;
3268 # Print it indented if tracing is on.
3269 DB::print_lineinfo( ' ' x $stack_depth,
3270 "$i:\t$DB::dbline[$i]" . $self->after );
3273 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3278 return $DB::dbline[$line];
3282 my ($self, $letter) = @_;
3284 return ($DB::cmd eq $letter);
3287 sub _DB__grab_control
3291 # Yes, grab control.
3292 if ($slave_editor) {
3294 # Tell the editor to update its position.
3295 $self->position("\032\032${DB::filename}:$line:0\n");
3296 DB::print_lineinfo($self->position());
3301 Special check: if we're in package C<DB::fake>, we've gone through the
3302 C<END> block at least once. We set up everything so that we can continue
3303 to enter commands and have a valid context to be in.
3307 elsif ( $DB::package eq 'DB::fake' ) {
3309 # Fallen off the end already.
3314 DB::print_help(<<EOP);
3315 Debugged program terminated. Use B<q> to quit or B<R> to restart,
3316 use B<o> I<inhibit_exit> to avoid stopping after program termination,
3317 B<h q>, B<h R> or B<h o> to get additional info.
3320 # Set the DB::eval context appropriately.
3321 $DB::package = 'main';
3322 $DB::usercontext = DB::_calc_usercontext($DB::package);
3323 } ## end elsif ($package eq 'DB::fake')
3327 If the program hasn't finished executing, we scan forward to the
3328 next executable line, print that out, build the prompt from the file and line
3329 number information, and print that.
3336 # Still somewhere in the midst of execution. Set up the
3338 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3339 # Perl 5 ones (sorry, we don't print Klingon
3342 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
3343 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
3344 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
3346 # Break up the prompt if it's really long.
3347 if ( length($self->prefix()) > 30 ) {
3348 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
3350 $self->infix(":\t");
3353 $self->infix("):\t");
3355 $self->prefix . $line. $self->infix
3356 . $self->_curr_line . $self->after
3360 # Print current line info, indenting if necessary.
3361 $self->_my_print_lineinfo($line, $self->position);
3364 my $line_i = sub { return $DB::dbline[$i]; };
3366 # Scan forward, stopping at either the end or the next
3368 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
3371 # Drop out on null statements, block closers, and comments.
3372 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
3374 # Drop out if the user interrupted us.
3377 # Append a newline if the line doesn't have one. Can happen
3378 # in eval'ed text, for instance.
3379 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
3381 # Next executable line.
3382 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
3384 $self->append_to_position($incr_pos);
3385 $self->_my_print_lineinfo($i, $incr_pos);
3386 } ## end for ($i = $line + 1 ; $i...
3387 } ## end else [ if ($slave_editor)
3392 sub _handle_t_command {
3395 my $levels = $self->cmd_args();
3397 if ((!length($levels)) or ($levels !~ /\D/)) {
3400 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
3401 print {$OUT} "Trace = "
3403 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3412 sub _handle_S_command {
3415 if (my ($print_all_subs, $should_reverse, $Spatt)
3416 = $self->cmd_args =~ /\A((!)?(.+))?\z/) {
3417 # $Spatt is the pattern (if any) to use.
3419 my $Srev = defined $should_reverse;
3420 # No args - print all subs.
3421 my $Snocheck = !defined $print_all_subs;
3423 # Need to make these sane here.
3427 # Search through the debugger's magical hash of subs.
3428 # If $nocheck is true, just print the sub name.
3429 # Otherwise, check it against the pattern. We then use
3430 # the XOR trick to reverse the condition as required.
3431 foreach $subname ( sort( keys %sub ) ) {
3432 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
3433 print $OUT $subname, "\n";
3442 sub _handle_V_command_and_X_command {
3445 $DB::cmd =~ s/^X\b/V $DB::package/;
3447 # Bare V commands get the currently-being-debugged package
3449 if ($self->_is_full('V')) {
3450 $DB::cmd = "V $DB::package";
3453 # V - show variables in package.
3454 if (my ($new_packname, $new_vars_str) =
3455 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
3457 # Save the currently selected filehandle and
3458 # force output to debugger's filehandle (dumpvar
3459 # just does "print" for output).
3460 my $savout = select($OUT);
3462 # Grab package name and variables to dump.
3463 $packname = $new_packname;
3464 my @vars = split( ' ', $new_vars_str );
3466 # If main::dumpvar isn't here, get it.
3467 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
3468 if ( defined &main::dumpvar ) {
3470 # We got it. Turn off subroutine entry/exit messages
3471 # for the moment, along with return values.
3475 # must detect sigpipe failures - not catching
3476 # then will cause the debugger to die.
3480 defined $option{dumpDepth}
3481 ? $option{dumpDepth}
3482 : -1, # assume -1 unless specified
3487 # The die doesn't need to include the $@, because
3488 # it will automatically get propagated for us.
3490 die unless $@ =~ /dumpvar print failed/;
3492 } ## end if (defined &main::dumpvar)
3495 # Couldn't load dumpvar.
3496 print $OUT "dumpvar.pl not available.\n";
3499 # Restore the output filehandle, and go round again.
3507 sub _handle_dash_command {
3510 if ($self->_is_full('-')) {
3512 # back up by a window; go to 1 if back too far.
3513 $start -= $incr + $window + 1;
3514 $start = 1 if $start <= 0;
3515 $incr = $window - 1;
3517 # Generate and execute a "l +" command (handled below).
3518 $DB::cmd = 'l ' . ($start) . '+';
3524 sub _n_or_s_commands_generic {
3525 my ($self, $new_val) = @_;
3527 next CMD if DB::_DB__is_finished();
3529 # Single step, but don't enter subs.
3532 # Save for empty command (repeat last).
3533 $laststep = $DB::cmd;
3538 my ($self, $letter, $new_val) = @_;
3540 if ($self->_is_full($letter)) {
3541 $self->_n_or_s_commands_generic($new_val);
3544 $self->_n_or_s_and_arg_commands_generic($letter, $new_val);
3550 sub _handle_n_command {
3553 return $self->_n_or_s('n', 2);
3556 sub _handle_s_command {
3559 return $self->_n_or_s('s', 1);
3562 sub _handle_r_command {
3565 # r - return from the current subroutine.
3566 if ($self->_is_full('r')) {
3568 # Can't do anything if the program's over.
3569 next CMD if DB::_DB__is_finished();
3571 # Turn on stack trace.
3572 $stack[$stack_depth] |= 1;
3574 # Print return value unless the stack is empty.
3575 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
3582 sub _handle_T_command {
3585 if ($self->_is_full('T')) {
3586 DB::print_trace( $OUT, 1 ); # skip DB
3593 sub _handle_w_command {
3596 DB::cmd_w( 'w', $self->cmd_args() );
3602 sub _handle_W_command {
3605 if (my $arg = $self->cmd_args) {
3606 DB::cmd_W( 'W', $arg );
3613 sub _handle_rc_recall_command {
3616 # $rc - recall command.
3617 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
3619 # No arguments, take one thing off history.
3620 pop(@hist) if length($DB::cmd) > 1;
3622 # Relative (- found)?
3623 # Y - index back from most recent (by 1 if bare minus)
3624 # N - go to that particular command slot or the last
3625 # thing if nothing following.
3628 scalar($minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist ))
3631 # Pick out the command desired.
3632 $DB::cmd = $hist[$self->cmd_verb];
3634 # Print the command to be executed and restart the loop
3635 # with that command in the buffer.
3636 print {$OUT} $DB::cmd, "\n";
3643 sub _handle_rc_search_history_command {
3646 # $rc pattern $rc - find a command in the history.
3647 if (my ($arg) = $DB::cmd =~ /\A$rc([^$rc].*)\z/) {
3649 # Create the pattern to use.
3653 # Toss off last entry if length is >1 (and it always is).
3654 pop(@hist) if length($DB::cmd) > 1;
3658 # Look backward through the history.
3660 for ( $i = $#hist ; $i ; --$i ) {
3661 # Stop if we find it.
3662 last SEARCH_HIST if $hist[$i] =~ /$pat/;
3668 print $OUT "No such command!\n\n";
3672 # Found it. Put it in the buffer, print it, and process it.
3673 $DB::cmd = $hist[$i];
3674 print $OUT $DB::cmd, "\n";
3681 sub _handle_H_command {
3684 if ($self->cmd_args =~ m#\A\*#) {
3685 @hist = @truehist = ();
3686 print $OUT "History cleansed\n";
3690 if (my ($num) = $self->cmd_args =~ /\A(?:-(\d+))?/) {
3692 # Anything other than negative numbers is ignored by
3693 # the (incorrect) pattern, so this test does nothing.
3694 $end = $num ? ( $#hist - $num ) : 0;
3696 # Set to the minimum if less than zero.
3697 $hist = 0 if $hist < 0;
3699 # Start at the end of the array.
3700 # Stay in while we're still above the ending value.
3701 # Tick back by one each time around the loop.
3704 for ( $i = $#hist ; $i > $end ; $i-- ) {
3706 # Print the command unless it has no arguments.
3707 print $OUT "$i: ", $hist[$i], "\n"
3708 unless $hist[$i] =~ /^.?$/;
3717 sub _handle_doc_command {
3720 # man, perldoc, doc - show manual pages.
3722 = $DB::cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
3723 DB::runman($man_page);
3730 sub _handle_p_command {
3733 my $print_cmd = 'print {$DB::OUT} ';
3734 # p - print (no args): print $_.
3735 if ($self->_is_full('p')) {
3736 $DB::cmd = $print_cmd . '$_';
3739 # p - print the given expression.
3740 $DB::cmd =~ s/\Ap\b/$print_cmd /;
3746 sub _handle_equal_sign_command {
3749 if ($DB::cmd =~ s/\A=\s*//) {
3751 if ( length $DB::cmd == 0 ) {
3753 # No args, get current aliases.
3754 @keys = sort keys %alias;
3756 elsif ( my ( $k, $v ) = ( $DB::cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3758 # Creating a new alias. $k is alias name, $v is
3761 # can't use $_ or kill //g state
3762 for my $x ( $k, $v ) {
3764 # Escape "alarm" characters.
3768 # Substitute key for value, using alarm chars
3769 # as separators (which is why we escaped them in
3771 $alias{$k} = "s\a$k\a$v\a";
3773 # Turn off standard warn and die behavior.
3774 local $SIG{__DIE__};
3775 local $SIG{__WARN__};
3778 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3780 # Nope. Bad alias. Say so and get out.
3781 print $OUT "Can't alias $k to $v: $@\n";
3786 # We'll only list the new one.
3788 } ## end elsif (my ($k, $v) = ($DB::cmd...
3790 # The argument is the alias to list.
3798 # Messy metaquoting: Trim the substitution code off.
3799 # We use control-G as the delimiter because it's not
3800 # likely to appear in the alias.
3801 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3804 print $OUT "$k\t= $1\n";
3806 elsif ( defined $alias{$k} ) {
3808 # Couldn't trim it off; just print the alias code.
3809 print $OUT "$k\t$alias{$k}\n";
3814 print "No alias for $k\n";
3816 } ## end for my $k (@keys)
3823 sub _handle_source_command {
3826 # source - read commands from a file (or pipe!) and execute.
3827 if (my $sourced_fn = $self->cmd_args) {
3828 if ( open my $fh, $sourced_fn ) {
3830 # Opened OK; stick it in the list of file handles.
3836 DB::_db_warn("Can't execute '$sourced_fn': $!\n");
3844 sub _handle_enable_disable_commands {
3847 my $which_cmd = $self->cmd_verb;
3848 my $position = $self->cmd_args;
3850 if ($position !~ /\s/) {
3851 my ($fn, $line_num);
3852 if ($position =~ m{\A\d+\z})
3854 $fn = $DB::filename;
3855 $line_num = $position;
3857 elsif (my ($new_fn, $new_line_num)
3858 = $position =~ m{\A(.*):(\d+)\z}) {
3859 ($fn, $line_num) = ($new_fn, $new_line_num);
3863 DB::_db_warn("Wrong spec for enable/disable argument.\n");
3867 if (DB::_has_breakpoint_data_ref($fn, $line_num)) {
3868 DB::_set_breakpoint_enabled_status($fn, $line_num,
3869 ($which_cmd eq 'enable' ? 1 : '')
3873 DB::_db_warn("No breakpoint set at ${fn}:${line_num}\n");
3883 sub _handle_save_command {
3886 if (my $new_fn = $self->cmd_args) {
3887 my $filename = $new_fn || '.perl5dbrc'; # default?
3888 if ( open my $fh, '>', $filename ) {
3890 # chomp to remove extraneous newlines from source'd files
3891 chomp( my @truelist =
3892 map { m/\A\s*(save|source)/ ? "#$_" : $_ }
3894 print {$fh} join( "\n", @truelist );
3895 print "commands saved in $filename\n";
3898 DB::_db_warn("Can't save debugger commands in '$new_fn': $!\n");
3906 sub _n_or_s_and_arg_commands_generic {
3907 my ($self, $letter, $new_val) = @_;
3909 # s - single-step. Remember the last command was 's'.
3910 if ($DB::cmd =~ s#\A\Q$letter\E\s#\$DB::single = $new_val;\n#) {
3911 $laststep = $letter;
3917 sub _handle_sh_command {
3920 # $sh$sh - run a shell command (if it's all ASCII).
3921 # Can't run shell commands with Unicode in the debugger, hmm.
3922 my $my_cmd = $DB::cmd;
3923 if ($my_cmd =~ m#\A$sh#gms) {
3925 if ($my_cmd =~ m#\G\z#cgms) {
3926 # Run the user's shell. If none defined, run Bourne.
3927 # We resume execution when the shell terminates.
3928 DB::_db_system( $ENV{SHELL} || "/bin/sh" );
3931 elsif ($my_cmd =~ m#\G$sh\s*(.*)#cgms) {
3936 elsif ($my_cmd =~ m#\G\s*(.*)#cgms) {
3937 DB::_db_system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3943 sub _handle_x_command {
3946 if ($DB::cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
3947 $onetimeDump = 'dump'; # main::dumpvar shows the output
3949 # handle special "x 3 blah" syntax XXX propagate
3950 # doc back to special variables.
3951 if ( $DB::cmd =~ s#\A\s*(\d+)(?=\s)# #) {
3952 $onetimedumpDepth = $1;
3959 sub _handle_q_command {
3962 if ($self->_is_full('q')) {
3971 sub _handle_cmd_wrapper_commands {
3974 DB::cmd_wrapper( $self->cmd_verb, $self->cmd_args, $line );
3978 sub _handle_special_char_cmd_wrapper_commands {
3981 # All of these commands were remapped in perl 5.8.0;
3982 # we send them off to the secondary dispatcher (see below).
3983 if (my ($cmd_letter, $my_arg) = $DB::cmd =~ /\A([<>\{]{1,2})\s*(.*)/so) {
3984 DB::cmd_wrapper( $cmd_letter, $my_arg, $line );
3995 # The following code may be executed now:
4000 C<sub> is called whenever a subroutine call happens in the program being
4001 debugged. The variable C<$DB::sub> contains the name of the subroutine
4004 The core function of this subroutine is to actually call the sub in the proper
4005 context, capturing its output. This of course causes C<DB::DB> to get called
4006 again, repeating until the subroutine ends and returns control to C<DB::sub>
4007 again. Once control returns, C<DB::sub> figures out whether or not to dump the
4008 return value, and returns its captured copy of the return value as its own
4009 return value. The value then feeds back into the program being debugged as if
4010 C<DB::sub> hadn't been there at all.
4012 C<sub> does all the work of printing the subroutine entry and exit messages
4013 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
4014 and also prints the return value if needed (for the C<r> command and if
4015 the 16 bit is set in C<$frame>).
4017 It also tracks the subroutine call depth by saving the current setting of
4018 C<$single> in the C<@stack> package global; if this exceeds the value in
4019 C<$deep>, C<sub> automatically turns on printing of the current depth by
4020 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
4021 of stop/don't stop on entry to subs set as it currently is set.
4023 =head3 C<caller()> support
4025 If C<caller()> is called from the package C<DB>, it provides some
4026 additional data, in the following order:
4032 The package name the sub was in
4034 =item * C<$filename>
4036 The filename it was defined in
4040 The line number it was defined on
4042 =item * C<$subroutine>
4044 The subroutine name; C<(eval)> if an C<eval>().
4048 1 if it has arguments, 0 if not
4050 =item * C<$wantarray>
4052 1 if array context, 0 if scalar context
4054 =item * C<$evaltext>
4056 The C<eval>() text, if any (undefined for C<eval BLOCK>)
4058 =item * C<$is_require>
4060 frame was created by a C<use> or C<require> statement
4064 pragma information; subject to change between versions
4068 pragma information; subject to change between versions
4070 =item * C<@DB::args>
4072 arguments with which the subroutine was invoked
4080 # We need to fully qualify the name ("DB::sub") to make "use strict;"
4081 # happy. -- Shlomi Fish
4083 sub _indent_print_line_info {
4084 my ($offset, $str) = @_;
4086 print_lineinfo( ' ' x ($stack_depth - $offset), $str);
4091 sub _print_frame_message {
4095 if ($frame & 4) { # Extended frame entry message
4096 _indent_print_line_info(-1, "in ");
4098 # Why -1? But it works! :-(
4099 # Because print_trace will call add 1 to it and then call
4100 # dump_trace; this results in our skipping -1+1 = 0 stack frames
4103 # Now it's 0 because we extracted a function.
4104 print_trace( $LINEINFO, 0, 1, 1, "$sub$al" );
4107 _indent_print_line_info(-1, "entering $sub$al\n" );
4115 # lock ourselves under threads
4118 # Whether or not the autoloader was running, a scalar to put the
4119 # sub's return value in (if needed), and an array to put the sub's
4120 # return value in (if needed).
4121 my ( $al, $ret, @ret ) = "";
4122 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) {
4123 print "creating new thread\n";
4126 # If the last ten characters are '::AUTOLOAD', note we've traced
4127 # into AUTOLOAD for $sub.
4128 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
4130 $al = " for $$sub" if defined $$sub;
4133 # We stack the stack pointer and then increment it to protect us
4134 # from a situation that might unwind a whole bunch of call frames
4135 # at once. Localizing the stack pointer means that it will automatically
4136 # unwind the same amount when multiple stack frames are unwound.
4137 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
4140 $#stack = $stack_depth;
4142 # Save current single-step setting.
4143 $stack[-1] = $single;
4145 # Turn off all flags except single-stepping.
4148 # If we've gotten really deeply recursed, turn on the flag that will
4149 # make us stop with the 'deep recursion' message.
4150 $single |= 4 if $stack_depth == $deep;
4152 # If frame messages are on ...
4154 _print_frame_message($al);
4155 # standard frame entry message
4157 my $print_exit_msg = sub {
4158 # Check for exit trace messages...
4161 if ($frame & 4) # Extended exit message
4163 _indent_print_line_info(0, "out ");
4164 print_trace( $LINEINFO, 0, 1, 1, "$sub$al" );
4168 _indent_print_line_info(0, "exited $sub$al\n" );
4174 # Determine the sub's return type, and capture appropriately.
4177 # Called in array context. call sub and capture output.
4178 # DB::DB will recursively get control again if appropriate; we'll come
4179 # back here when the sub is finished.
4185 # Pop the single-step value back off the stack.
4186 $single |= $stack[ $stack_depth-- ];
4188 $print_exit_msg->();
4190 # Print the return info if we need to.
4191 if ( $doret eq $stack_depth or $frame & 16 ) {
4193 # Turn off output record separator.
4195 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4197 # Indent if we're printing because of $frame tracing.
4200 print {$fh} ' ' x $stack_depth;
4203 # Print the return value.
4204 print {$fh} "list context return from $sub:\n";
4205 dumpit( $fh, \@ret );
4207 # And don't print it again.
4209 } ## end if ($doret eq $stack_depth...
4210 # And we have to return the return value now.
4212 } ## end if (wantarray)
4216 if ( defined wantarray ) {
4218 # Save the value if it's wanted at all.
4223 # Void return, explicitly.
4228 # Pop the single-step value off the stack.
4229 $single |= $stack[ $stack_depth-- ];
4231 # If we're doing exit messages...
4232 $print_exit_msg->();
4234 # If we are supposed to show the return value... same as before.
4235 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
4237 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4238 print $fh ( ' ' x $stack_depth ) if $frame & 16;
4241 ? "scalar context return from $sub: "
4242 : "void context return from $sub\n"
4244 dumpit( $fh, $ret ) if defined wantarray;
4246 } ## end if ($doret eq $stack_depth...
4248 # Return the appropriate scalar value.
4250 } ## end else [ if (wantarray)
4257 # lock ourselves under threads
4260 # Whether or not the autoloader was running, a scalar to put the
4261 # sub's return value in (if needed), and an array to put the sub's
4262 # return value in (if needed).
4263 my ( $al, $ret, @ret ) = "";
4264 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
4265 print "creating new thread\n";
4268 # If the last ten characters are C'::AUTOLOAD', note we've traced
4269 # into AUTOLOAD for $sub.
4270 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
4274 # We stack the stack pointer and then increment it to protect us
4275 # from a situation that might unwind a whole bunch of call frames
4276 # at once. Localizing the stack pointer means that it will automatically
4277 # unwind the same amount when multiple stack frames are unwound.
4278 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
4281 $#stack = $stack_depth;
4283 # Save current single-step setting.
4284 $stack[-1] = $single;
4286 # Turn off all flags except single-stepping.
4287 # Use local so the single-step value is popped back off the
4289 local $single = $single & 1;
4291 # If we've gotten really deeply recursed, turn on the flag that will
4292 # make us stop with the 'deep recursion' message.
4293 $single |= 4 if $stack_depth == $deep;
4295 # If frame messages are on ...
4296 _print_frame_message($al);
4298 # call the original lvalue sub.
4302 # Abstracting common code from multiple places elsewhere:
4303 sub depth_print_lineinfo {
4304 my $always_print = shift;
4306 print_lineinfo( @_ ) if ($always_print or $stack_depth < $trace_to_depth);
4309 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
4311 In Perl 5.8.0, there was a major realignment of the commands and what they did,
4312 Most of the changes were to systematize the command structure and to eliminate
4313 commands that threw away user input without checking.
4315 The following sections describe the code added to make it easy to support
4316 multiple command sets with conflicting command names. This section is a start
4317 at unifying all command processing to make it simpler to develop commands.
4319 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
4320 number, and C<$dbline> (the current line) as arguments.
4322 Support functions in this section which have multiple modes of failure C<die>
4323 on error; the rest simply return a false value.
4325 The user-interface functions (all of the C<cmd_*> functions) just output
4330 The C<%set> hash defines the mapping from command letter to subroutine
4333 C<%set> is a two-level hash, indexed by set name and then by command name.
4334 Note that trying to set the CommandSet to C<foobar> simply results in the
4335 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
4344 'A' => 'pre580_null',
4346 'B' => 'pre580_null',
4347 'd' => 'pre580_null',
4350 'M' => 'pre580_null',
4352 'o' => 'pre580_null',
4358 '<' => 'pre590_prepost',
4359 '<<' => 'pre590_prepost',
4360 '>' => 'pre590_prepost',
4361 '>>' => 'pre590_prepost',
4362 '{' => 'pre590_prepost',
4363 '{{' => 'pre590_prepost',
4367 my %breakpoints_data;
4369 sub _has_breakpoint_data_ref {
4370 my ($filename, $line) = @_;
4373 exists( $breakpoints_data{$filename} )
4375 exists( $breakpoints_data{$filename}{$line} )
4379 sub _get_breakpoint_data_ref {
4380 my ($filename, $line) = @_;
4382 return ($breakpoints_data{$filename}{$line} ||= +{});
4385 sub _delete_breakpoint_data_ref {
4386 my ($filename, $line) = @_;
4388 delete($breakpoints_data{$filename}{$line});
4389 if (! scalar(keys( %{$breakpoints_data{$filename}} )) ) {
4390 delete($breakpoints_data{$filename});
4396 sub _set_breakpoint_enabled_status {
4397 my ($filename, $line, $status) = @_;
4399 _get_breakpoint_data_ref($filename, $line)->{'enabled'} =
4406 sub _enable_breakpoint_temp_enabled_status {
4407 my ($filename, $line) = @_;
4409 _get_breakpoint_data_ref($filename, $line)->{'temp_enabled'} = 1;
4414 sub _cancel_breakpoint_temp_enabled_status {
4415 my ($filename, $line) = @_;
4417 my $ref = _get_breakpoint_data_ref($filename, $line);
4419 delete ($ref->{'temp_enabled'});
4422 _delete_breakpoint_data_ref($filename, $line);
4428 sub _is_breakpoint_enabled {
4429 my ($filename, $line) = @_;
4431 my $data_ref = _get_breakpoint_data_ref($filename, $line);
4432 return ($data_ref->{'enabled'} || $data_ref->{'temp_enabled'});
4435 =head2 C<cmd_wrapper()> (API)
4437 C<cmd_wrapper()> allows the debugger to switch command sets
4438 depending on the value of the C<CommandSet> option.
4440 It tries to look up the command in the C<%set> package-level I<lexical>
4441 (which means external entities can't fiddle with it) and create the name of
4442 the sub to call based on the value found in the hash (if it's there). I<All>
4443 of the commands to be handled in a set have to be added to C<%set>; if they
4444 aren't found, the 5.8.0 equivalent is called (if there is one).
4446 This code uses symbolic references.
4453 my $dblineno = shift;
4455 # Assemble the command subroutine's name by looking up the
4456 # command set and command name in %set. If we can't find it,
4457 # default to the older version of the command.
4459 . ( $set{$CommandSet}{$cmd}
4460 || ( $cmd =~ /\A[<>{]+/o ? 'prepost' : $cmd ) );
4462 # Call the command subroutine, call it by name.
4463 return __PACKAGE__->can($call)->( $cmd, $line, $dblineno );
4464 } ## end sub cmd_wrapper
4466 =head3 C<cmd_a> (command)
4468 The C<a> command handles pre-execution actions. These are associated with a
4469 particular line, so they're stored in C<%dbline>. We default to the current
4470 line if none is specified.
4476 my $line = shift || ''; # [.|line] expr
4479 # If it's dot (here), or not all digits, use the current line.
4480 $line =~ s/\A\./$dbline/;
4482 # Should be a line number followed by an expression.
4483 if ( my ($lineno, $expr) = $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
4485 if (! length($lineno)) {
4489 # If we have an expression ...
4490 if ( length $expr ) {
4492 # ... but the line isn't breakable, complain.
4493 if ( $dbline[$lineno] == 0 ) {
4495 "Line $lineno($dbline[$lineno]) does not have an action?\n";
4499 # It's executable. Record that the line has an action.
4500 $had_breakpoints{$filename} |= 2;
4502 # Remove any action, temp breakpoint, etc.
4503 $dbline{$lineno} =~ s/\0[^\0]*//;
4505 # Add the action to the line.
4506 $dbline{$lineno} .= "\0" . action($expr);
4508 _set_breakpoint_enabled_status($filename, $lineno, 1);
4510 } ## end if (length $expr)
4511 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
4516 "Adding an action requires an optional lineno and an expression\n"
4521 =head3 C<cmd_A> (command)
4523 Delete actions. Similar to above, except the delete code is in a separate
4524 subroutine, C<delete_action>.
4530 my $line = shift || '';
4534 $line =~ s/^\./$dbline/;
4536 # Call delete_action with a null param to delete them all.
4537 # The '1' forces the eval to be true. It'll be false only
4538 # if delete_action blows up for some reason, in which case
4539 # we print $@ and get out.
4540 if ( $line eq '*' ) {
4541 if (! eval { _delete_all_actions(); 1 }) {
4547 # There's a real line number. Pass it to delete_action.
4548 # Error trapping is as above.
4549 elsif ( $line =~ /^(\S.*)/ ) {
4550 if (! eval { delete_action($1); 1 }) {
4556 # Swing and a miss. Bad syntax.
4559 "Deleting an action requires a line number, or '*' for all\n" ; # hint
4563 =head3 C<delete_action> (API)
4565 C<delete_action> accepts either a line number or C<undef>. If a line number
4566 is specified, we check for the line being executable (if it's not, it
4567 couldn't have had an action). If it is, we just take the action off (this
4568 will get any kind of an action, including breakpoints).
4572 sub _remove_action_from_dbline {
4575 $dbline{$i} =~ s/\0[^\0]*//; # \^a
4576 delete $dbline{$i} if $dbline{$i} eq '';
4581 sub _delete_all_actions {
4582 print {$OUT} "Deleting all actions...\n";
4584 for my $file ( keys %had_breakpoints ) {
4585 local *dbline = $main::{ '_<' . $file };
4588 for my $i (1 .. $max) {
4589 if ( defined $dbline{$i} ) {
4590 _remove_action_from_dbline($i);
4594 unless ( $had_breakpoints{$file} &= ~2 ) {
4595 delete $had_breakpoints{$file};
4605 if ( defined($i) ) {
4607 die "Line $i has no action .\n" if $dbline[$i] == 0;
4609 # Nuke whatever's there.
4610 _remove_action_from_dbline($i);
4613 _delete_all_actions();
4617 =head3 C<cmd_b> (command)
4619 Set breakpoints. Since breakpoints can be set in so many places, in so many
4620 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4621 we try to parse the command type, and then shuttle it off to an appropriate
4622 subroutine to actually do the work of setting the breakpoint in the right
4629 my $line = shift; # [.|line] [cond]
4632 my $default_cond = sub {
4634 return length($cond) ? $cond : '1';
4637 # Make . the current line number if it's there..
4638 $line =~ s/^\.(\s|\z)/$dbline$1/;
4640 # No line number, no condition. Simple break on current line.
4641 if ( $line =~ /^\s*$/ ) {
4642 cmd_b_line( $dbline, 1 );
4645 # Break on load for a file.
4646 elsif ( my ($file) = $line =~ /^load\b\s*(.*)/ ) {
4651 # b compile|postpone <some sub> [<condition>]
4652 # The interpreter actually traps this one for us; we just put the
4653 # necessary condition in the %postponed hash.
4654 elsif ( my ($action, $subname, $cond)
4655 = $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4657 # De-Perl4-ify the name - ' separators to ::.
4658 $subname =~ s/'/::/g;
4660 # Qualify it into the current package unless it's already qualified.
4661 $subname = "${package}::" . $subname unless $subname =~ /::/;
4663 # Add main if it starts with ::.
4664 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4666 # Save the break type for this sub.
4667 $postponed{$subname} = (($action eq 'postpone')
4668 ? ( "break +0 if " . $default_cond->($cond) )
4670 } ## end elsif ($line =~ ...
4671 # b <filename>:<line> [<condition>]
4672 elsif (my ($filename, $line_num, $cond)
4673 = $line =~ /\A(\S+[^:]):(\d+)\s*(.*)/ms) {
4674 cmd_b_filename_line(
4677 (length($cond) ? $cond : '1'),
4680 # b <sub name> [<condition>]
4681 elsif ( my ($new_subname, $new_cond) =
4682 $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4685 $subname = $new_subname;
4686 cmd_b_sub( $subname, $default_cond->($new_cond) );
4689 # b <line> [<condition>].
4690 elsif ( my ($line_n, $cond) = $line =~ /^(\d*)\s*(.*)/ ) {
4692 # Capture the line. If none, it's the current line.
4693 $line = $line_n || $dbline;
4696 cmd_b_line( $line, $default_cond->($cond) );
4699 # Line didn't make sense.
4701 print "confused by line($line)?\n";
4707 =head3 C<break_on_load> (API)
4709 We want to break when this file is loaded. Mark this file in the
4710 C<%break_on_load> hash, and note that it has a breakpoint in
4711 C<%had_breakpoints>.
4717 $break_on_load{$file} = 1;
4718 $had_breakpoints{$file} |= 1;
4721 =head3 C<report_break_on_load> (API)
4723 Gives us an array of filenames that are set to break on load. Note that
4724 only files with break-on-load are in here, so simply showing the keys
4729 sub report_break_on_load {
4730 sort keys %break_on_load;
4733 =head3 C<cmd_b_load> (command)
4735 We take the file passed in and try to find it in C<%INC> (which maps modules
4736 to files they came from). We mark those files for break-on-load via
4737 C<break_on_load> and then report that it was done.
4745 # This is a block because that way we can use a redo inside it
4746 # even without there being any looping structure at all outside it.
4749 # Save short name and full path if found.
4751 push @files, $::INC{$file} if $::INC{$file};
4753 # Tack on .pm and do it again unless there was a '.' in the name
4755 $file .= '.pm', redo unless $file =~ /\./;
4758 # Do the real work here.
4759 break_on_load($_) for @files;
4761 # All the files that have break-on-load breakpoints.
4762 @files = report_break_on_load;
4764 # Normalize for the purposes of our printing this.
4767 print $OUT "Will stop on load of '@files'.\n";
4768 } ## end sub cmd_b_load
4770 =head3 C<$filename_error> (API package global)
4772 Several of the functions we need to implement in the API need to work both
4773 on the current file and on other files. We don't want to duplicate code, so
4774 C<$filename_error> is used to contain the name of the file that's being
4775 worked on (if it's not the current one).
4777 We can now build functions in pairs: the basic function works on the current
4778 file, and uses C<$filename_error> as part of its error message. Since this is
4779 initialized to C<"">, no filename will appear when we are working on the
4782 The second function is a wrapper which does the following:
4788 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4792 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4796 Calls the first function.
4798 The first function works on the I<current> file (i.e., the one we changed to),
4799 and prints C<$filename_error> in the error message (the name of the other file)
4800 if it needs to. When the functions return, C<*dbline> is restored to point
4801 to the actual current file (the one we're executing in) and
4802 C<$filename_error> is restored to C<"">. This restores everything to
4803 the way it was before the second function was called at all.
4805 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4812 use vars qw($filename_error);
4813 $filename_error = '';
4815 =head3 breakable_line(from, to) (API)
4817 The subroutine decides whether or not a line in the current file is breakable.
4818 It walks through C<@dbline> within the range of lines specified, looking for
4819 the first line that is breakable.
4821 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4822 first line I<after> C<$to> that's breakable, if there is one.
4824 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4825 first line I<before> C<$to> that's breakable, if there is one.
4829 sub breakable_line {
4831 my ( $from, $to ) = @_;
4833 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4836 # If there are at least 2 arguments, we're trying to search a range.
4839 # $delta is positive for a forward search, negative for a backward one.
4840 my $delta = $from < $to ? +1 : -1;
4842 # Keep us from running off the ends of the file.
4843 my $limit = $delta > 0 ? $#dbline : 1;
4845 # Clever test. If you're a mathematician, it's obvious why this
4846 # test works. If not:
4847 # If $delta is positive (going forward), $limit will be $#dbline.
4848 # If $to is less than $limit, ($limit - $to) will be positive, times
4849 # $delta of 1 (positive), so the result is > 0 and we should use $to
4850 # as the stopping point.
4852 # If $to is greater than $limit, ($limit - $to) is negative,
4853 # times $delta of 1 (positive), so the result is < 0 and we should
4854 # use $limit ($#dbline) as the stopping point.
4856 # If $delta is negative (going backward), $limit will be 1.
4857 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4858 # (negative) so the result is > 0, and we use $to as the stopping
4861 # If $to is less than zero, ($limit - $to) will be positive,
4862 # times $delta of -1 (negative), so the result is not > 0, and
4863 # we use $limit (1) as the stopping point.
4865 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4866 # (negative), still giving zero; the result is not > 0, and
4867 # we use $limit (1) as the stopping point.
4869 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4870 # (negative), giving a positive (>0) value, so we'll set $limit to
4873 $limit = $to if ( $limit - $to ) * $delta > 0;
4875 # The real search loop.
4876 # $i starts at $from (the point we want to start searching from).
4877 # We move through @dbline in the appropriate direction (determined
4878 # by $delta: either -1 (back) or +1 (ahead).
4879 # We stay in as long as we haven't hit an executable line
4880 # ($dbline[$i] == 0 means not executable) and we haven't reached
4881 # the limit yet (test similar to the above).
4882 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4884 } ## end if (@_ >= 2)
4886 # If $i points to a line that is executable, return that.
4887 return $i unless $dbline[$i] == 0;
4889 # Format the message and print it: no breakable lines in range.
4890 my ( $pl, $upto ) = ( '', '' );
4891 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4893 # If there's a filename in filename_error, we'll see it.
4895 die "Line$pl $from$upto$filename_error not breakable\n";
4896 } ## end sub breakable_line
4898 =head3 breakable_line_in_filename(file, from, to) (API)
4900 Like C<breakable_line>, but look in another file.
4904 sub breakable_line_in_filename {
4906 # Capture the file name.
4909 # Swap the magic line array over there temporarily.
4910 local *dbline = $main::{ '_<' . $f };
4912 # If there's an error, it's in this other file.
4913 local $filename_error = " of '$f'";
4915 # Find the breakable line.
4918 # *dbline and $filename_error get restored when this block ends.
4920 } ## end sub breakable_line_in_filename
4922 =head3 break_on_line(lineno, [condition]) (API)
4924 Adds a breakpoint with the specified condition (or 1 if no condition was
4925 specified) to the specified line. Dies if it can't.
4931 my $cond = @_ ? shift(@_) : 1;
4937 # Woops, not a breakable line. $filename_error allows us to say
4938 # if it was in a different file.
4939 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4941 # Mark this file as having breakpoints in it.
4942 $had_breakpoints{$filename} |= 1;
4944 # If there is an action or condition here already ...
4945 if ( $dbline{$i} ) {
4947 # ... swap this condition for the existing one.
4948 $dbline{$i} =~ s/^[^\0]*/$cond/;
4952 # Nothing here - just add the condition.
4953 $dbline{$i} = $cond;
4955 _set_breakpoint_enabled_status($filename, $i, 1);
4959 } ## end sub break_on_line
4961 =head3 cmd_b_line(line, [condition]) (command)
4963 Wrapper for C<break_on_line>. Prints the failure message if it
4969 if (not eval { break_on_line(@_); 1 }) {
4971 print $OUT $@ and return;
4975 } ## end sub cmd_b_line
4977 =head3 cmd_b_filename_line(line, [condition]) (command)
4979 Wrapper for C<break_on_filename_line>. Prints the failure message if it
4984 sub cmd_b_filename_line {
4985 if (not eval { break_on_filename_line(@_); 1 }) {
4987 print $OUT $@ and return;
4993 =head3 break_on_filename_line(file, line, [condition]) (API)
4995 Switches to the file specified and then calls C<break_on_line> to set
5000 sub break_on_filename_line {
5003 my $cond = @_ ? shift(@_) : 1;
5005 # Switch the magical hash temporarily.
5006 local *dbline = $main::{ '_<' . $f };
5008 # Localize the variables that break_on_line uses to make its message.
5009 local $filename_error = " of '$f'";
5010 local $filename = $f;
5012 # Add the breakpoint.
5013 break_on_line( $i, $cond );
5016 } ## end sub break_on_filename_line
5018 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
5020 Switch to another file, search the range of lines specified for an
5021 executable one, and put a breakpoint on the first one you find.
5025 sub break_on_filename_line_range {
5029 my $cond = @_ ? shift(@_) : 1;
5031 # Find a breakable line if there is one.
5032 my $i = breakable_line_in_filename( $f, $from, $to );
5034 # Add the breakpoint.
5035 break_on_filename_line( $f, $i, $cond );
5038 } ## end sub break_on_filename_line_range
5040 =head3 subroutine_filename_lines(subname, [condition]) (API)
5042 Search for a subroutine within a given file. The condition is ignored.
5043 Uses C<find_sub> to locate the desired subroutine.
5047 sub subroutine_filename_lines {
5048 my ( $subname ) = @_;
5050 # Returned value from find_sub() is fullpathname:startline-endline.
5051 # The match creates the list (fullpathname, start, end).
5052 return (find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/);
5053 } ## end sub subroutine_filename_lines
5055 =head3 break_subroutine(subname) (API)
5057 Places a break on the first line possible in the specified subroutine. Uses
5058 C<subroutine_filename_lines> to find the subroutine, and
5059 C<break_on_filename_line_range> to place the break.
5063 sub break_subroutine {
5064 my $subname = shift;
5066 # Get filename, start, and end.
5067 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
5068 or die "Subroutine $subname not found.\n";
5071 # Null condition changes to '1' (always true).
5072 my $cond = @_ ? shift(@_) : 1;
5074 # Put a break the first place possible in the range of lines
5075 # that make up this subroutine.
5076 break_on_filename_line_range( $file, $s, $e, $cond );
5079 } ## end sub break_subroutine
5081 =head3 cmd_b_sub(subname, [condition]) (command)
5083 We take the incoming subroutine name and fully-qualify it as best we can.
5087 =item 1. If it's already fully-qualified, leave it alone.
5089 =item 2. Try putting it in the current package.
5091 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
5093 =item 4. If it starts with '::', put it in 'main::'.
5097 After all this cleanup, we call C<break_subroutine> to try to set the
5103 my $subname = shift;
5104 my $cond = @_ ? shift : 1;
5106 # If the subname isn't a code reference, qualify it so that
5107 # break_subroutine() will work right.
5108 if ( ref($subname) ne 'CODE' ) {
5111 $subname =~ s/'/::/g;
5114 # Put it in this package unless it's already qualified.
5115 if ($subname !~ /::/)
5117 $subname = $package . '::' . $subname;
5120 # Requalify it into CORE::GLOBAL if qualifying it into this
5121 # package resulted in its not being defined, but only do so
5122 # if it really is in CORE::GLOBAL.
5123 my $core_name = "CORE::GLOBAL::$s";
5124 if ((!defined(&$subname))
5126 and (defined &{$core_name}))
5128 $subname = $core_name;
5131 # Put it in package 'main' if it has a leading ::.
5132 if ($subname =~ /\A::/)
5134 $subname = "main" . $subname;
5136 } ## end if ( ref($subname) ne 'CODE' ) {
5138 # Try to set the breakpoint.
5139 if (not eval { break_subroutine( $subname, $cond ); 1 }) {
5146 } ## end sub cmd_b_sub
5148 =head3 C<cmd_B> - delete breakpoint(s) (command)
5150 The command mostly parses the command line and tries to turn the argument
5151 into a line spec. If it can't, it uses the current line. It then calls
5152 C<delete_breakpoint> to actually do the work.
5154 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
5155 thereby deleting all the breakpoints.
5162 # No line spec? Use dbline.
5163 # If there is one, use it if it's non-zero, or wipe it out if it is.
5164 my $line = ( $_[0] =~ /\A\./ ) ? $dbline : (shift || '');
5167 # If the line was dot, make the line the current one.
5168 $line =~ s/^\./$dbline/;
5170 # If it's * we're deleting all the breakpoints.
5171 if ( $line eq '*' ) {
5172 if (not eval { delete_breakpoint(); 1 }) {
5177 # If there is a line spec, delete the breakpoint on that line.
5178 elsif ( $line =~ /\A(\S.*)/ ) {
5179 if (not eval { delete_breakpoint( $line || $dbline ); 1 }) {
5183 } ## end elsif ($line =~ /^(\S.*)/)
5188 "Deleting a breakpoint requires a line number, or '*' for all\n"
5195 =head3 delete_breakpoint([line]) (API)
5197 This actually does the work of deleting either a single breakpoint, or all
5200 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
5201 just drop out with a message saying so. If it is, we remove the condition
5202 part of the 'condition\0action' that says there's a breakpoint here. If,
5203 after we've done that, there's nothing left, we delete the corresponding
5204 line in C<%dbline> to signal that no action needs to be taken for this line.
5206 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
5207 which lists all currently-loaded files which have breakpoints. We then look
5208 at each line in each of these files, temporarily switching the C<%dbline>
5209 and C<@dbline> structures to point to the files in question, and do what
5210 we did in the single line case: delete the condition in C<@dbline>, and
5211 delete the key in C<%dbline> if nothing's left.
5213 We then wholesale delete C<%postponed>, C<%postponed_file>, and
5214 C<%break_on_load>, because these structures contain breakpoints for files
5215 and code that haven't been loaded yet. We can just kill these off because there
5216 are no magical debugger structures associated with them.
5220 sub _remove_breakpoint_entry {
5224 _delete_breakpoint_data_ref($fn, $i);
5229 sub _delete_all_breakpoints {
5230 print {$OUT} "Deleting all breakpoints...\n";
5232 # %had_breakpoints lists every file that had at least one
5234 for my $fn ( keys %had_breakpoints ) {
5236 # Switch to the desired file temporarily.
5237 local *dbline = $main::{ '_<' . $fn };
5241 # For all lines in this file ...
5242 for my $i (1 .. $max) {
5244 # If there's a breakpoint or action on this line ...
5245 if ( defined $dbline{$i} ) {
5247 # ... remove the breakpoint.
5248 $dbline{$i} =~ s/\A[^\0]+//;
5249 if ( $dbline{$i} =~ s/\A\0?\z// ) {
5250 # Remove the entry altogether if no action is there.
5251 _remove_breakpoint_entry($fn, $i);
5253 } ## end if (defined $dbline{$i...
5254 } ## end for $i (1 .. $max)
5256 # If, after we turn off the "there were breakpoints in this file"
5257 # bit, the entry in %had_breakpoints for this file is zero,
5258 # we should remove this file from the hash.
5259 if ( not $had_breakpoints{$fn} &= (~1) ) {
5260 delete $had_breakpoints{$fn};
5262 } ## end for my $fn (keys %had_breakpoints)
5264 # Kill off all the other breakpoints that are waiting for files that
5265 # haven't been loaded yet.
5267 undef %postponed_file;
5268 undef %break_on_load;
5273 sub _delete_breakpoint_from_line {
5276 # Woops. This line wasn't breakable at all.
5277 die "Line $i not breakable.\n" if $dbline[$i] == 0;
5279 # Kill the condition, but leave any action.
5280 $dbline{$i} =~ s/\A[^\0]*//;
5282 # Remove the entry entirely if there's no action left.
5283 if ($dbline{$i} eq '') {
5284 _remove_breakpoint_entry($filename, $i);
5290 sub delete_breakpoint {
5293 # If we got a line, delete just that one.
5294 if ( defined($i) ) {
5295 _delete_breakpoint_from_line($i);
5297 # No line; delete them all.
5299 _delete_all_breakpoints();
5305 =head3 cmd_stop (command)
5307 This is meant to be part of the new command API, but it isn't called or used
5308 anywhere else in the debugger. XXX It is probably meant for use in development
5313 sub cmd_stop { # As on ^C, but not signal-safy.
5317 =head3 C<cmd_e> - threads
5319 Display the current thread id:
5323 This could be how (when implemented) to send commands to this thread id (e cmd)
5324 or that thread id (e tid cmd).
5331 unless (exists($INC{'threads.pm'})) {
5332 print "threads not loaded($ENV{PERL5DB_THREADED})
5333 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5335 my $tid = threads->tid;
5336 print "thread id: $tid\n";
5340 =head3 C<cmd_E> - list of thread ids
5342 Display the list of available thread ids:
5346 This could be used (when implemented) to send commands to all threads (E cmd).
5353 unless (exists($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 $tid = threads->tid;
5358 print "thread ids: ".join(', ',
5359 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
5364 =head3 C<cmd_h> - help command (command)
5366 Does the work of either
5372 Showing all the debugger help
5376 Showing help for a specific command
5383 use vars qw($summary);
5388 # If we have no operand, assume null.
5389 my $line = shift || '';
5391 # 'h h'. Print the long-format help.
5392 if ( $line =~ /\Ah\s*\z/ ) {
5396 # 'h <something>'. Search for the command and print only its help.
5397 elsif ( my ($asked) = $line =~ /\A(\S.*)\z/ ) {
5399 # support long commands; otherwise bogus errors
5400 # happen when you ask for h on <CR> for example
5401 my $qasked = quotemeta($asked); # for searching; we don't
5402 # want to use it as a pattern.
5403 # XXX: finds CR but not <CR>
5405 # Search the help string for the command.
5407 $help =~ /^ # Start of a line
5409 (?:[IB]<) # Optional markup
5410 $qasked # The requested command
5415 # It's there; pull it out and print it.
5419 (?:[IB]<) # Optional markup
5420 $qasked # The command
5421 ([\s\S]*?) # Description line(s)
5422 \n) # End of last description line
5423 (?!\s) # Next line not starting with
5432 # Not found; not a debugger command.
5434 print_help("B<$asked> is not a debugger command.\n");
5436 } ## end elsif ($line =~ /^(\S.*)$/)
5438 # 'h' - print the summary help.
5440 print_help($summary);
5444 =head3 C<cmd_i> - inheritance display
5446 Display the (nested) parentage of the module or object given.
5453 foreach my $isa ( split( /\s+/, $line ) ) {
5455 # The &-call is here to ascertain the mutability of @_.
5463 defined( ${"$_\::VERSION"} )
5464 ? ' ' . ${"$_\::VERSION"}
5466 } @{mro::get_linear_isa(ref($isa) || $isa)}
5472 =head3 C<cmd_l> - list lines (command)
5474 Most of the command is taken up with transforming all the different line
5475 specification syntaxes into 'start-stop'. After that is done, the command
5476 runs a loop over C<@dbline> for the specified range of lines. It handles
5477 the printing of each line and any markers (C<==E<gt>> for current line,
5478 C<b> for break on this line, C<a> for action on this line, C<:> for this
5481 We save the last line listed in the C<$start> global for further listing
5488 foreach my $v (@_) {
5498 foreach my $v (@_) {
5506 sub _minify_to_max {
5509 $$ref = _min($$ref, $max);
5514 sub _cmd_l_handle_var_name {
5515 my $var_name = shift;
5517 $evalarg = $var_name;
5519 my ($s) = DB::eval();
5521 # Ooops. Bad scalar.
5523 print {$OUT} "Error: $@\n";
5527 # Good scalar. If it's a reference, find what it points to.
5529 print {$OUT} "Interpreted as: $1 $s\n";
5532 # Call self recursively to really do the command.
5533 return _cmd_l_main( $s );
5536 sub _cmd_l_handle_subname {
5541 $subname =~ s/\'/::/;
5543 # Put it in this package unless it starts with ::.
5544 $subname = $package . "::" . $subname unless $subname =~ /::/;
5546 # Put it in CORE::GLOBAL if t doesn't start with :: and
5547 # it doesn't live in this package and it lives in CORE::GLOBAL.
5548 $subname = "CORE::GLOBAL::$s"
5549 if not defined &$subname
5551 and defined &{"CORE::GLOBAL::$s"};
5553 # Put leading '::' names into 'main::'.
5554 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
5556 # Get name:start-stop from find_sub, and break this up at
5558 my @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
5560 # Pull off start-stop.
5561 my $subrange = pop @pieces;
5563 # If the name contained colons, the split broke it up.
5564 # Put it back together.
5565 $file = join( ':', @pieces );
5567 # If we're not in that file, switch over to it.
5568 if ( $file ne $filename ) {
5569 if (! $slave_editor) {
5570 print {$OUT} "Switching to file '$file'.\n";
5573 # Switch debugger's magic structures.
5574 *dbline = $main::{ '_<' . $file };
5577 } ## end if ($file ne $filename)
5579 # Subrange is 'start-stop'. If this is less than a window full,
5580 # swap it to 'start+', which will list a window from the start point.
5582 if ( eval($subrange) < -$window ) {
5583 $subrange =~ s/-.*/+/;
5586 # Call self recursively to list the range.
5587 return _cmd_l_main( $subrange );
5588 } ## end if ($subrange)
5592 print {$OUT} "Subroutine $subname not found.\n";
5598 # Compute new range to list.
5599 $incr = $window - 1;
5602 return _cmd_l_main( $start . '-' . ( $start + $incr ) );
5606 my ($new_start, $new_incr) = @_;
5608 # Don't reset start for 'l +nnn'.
5609 $start = $new_start if $new_start;
5611 # Increment for list. Use window size if not specified.
5612 # (Allows 'l +' to work.)
5613 $incr = $new_incr || ($window - 1);
5615 # Create a line range we'll understand, and recurse to do it.
5616 return _cmd_l_main( $start . '-' . ( $start + $incr ) );
5619 sub _cmd_l_calc_initial_end_and_i {
5620 my ($spec, $start_match, $end_match) = @_;
5622 # Determine end point; use end of file if not specified.
5623 my $end = ( !defined $start_match ) ? $max :
5624 ( $end_match ? $end_match : $start_match );
5626 # Go on to the end, and then stop.
5627 _minify_to_max(\$end);
5629 # Determine start line.
5630 my $i = $start_match;
5644 my ($spec, $current_line, $start_match, $end_match) = @_;
5647 _cmd_l_calc_initial_end_and_i($spec, $start_match, $end_match);
5649 # If we're running under a slave editor, force it to show the lines.
5650 if ($slave_editor) {
5651 print {$OUT} "\032\032$filename:$i:0\n";
5654 # We're doing it ourselves. We want to show the line and special
5656 # - the current line in execution
5657 # - whether a line is breakable or not
5658 # - whether a line has a break or not
5659 # - whether a line has an action or not
5662 for ( ; $i <= $end ; $i++ ) {
5664 # Check for breakpoints and actions.
5665 my ( $stop, $action );
5667 ( $stop, $action ) = split( /\0/, $dbline{$i} );
5670 # ==> if this is the current line in execution,
5671 # : if it's breakable.
5673 ( $i == $current_line and $filename eq $filename_ini )
5675 : ( $dbline[$i] + 0 ? ':' : ' ' );
5677 # Add break and action indicators.
5678 $arrow .= 'b' if $stop;
5679 $arrow .= 'a' if $action;
5682 print {$OUT} "$i$arrow\t", $dbline[$i];
5684 # Move on to the next line. Drop out on an interrupt.
5689 } ## end for (; $i <= $end ; $i++)
5691 # Line the prompt up; print a newline if the last line listed
5692 # didn't have a newline.
5693 if ($dbline[ $i - 1 ] !~ /\n\z/) {
5696 } ## end else [ if ($slave_editor)
5698 # Save the point we last listed to in case another relative 'l'
5699 # command is desired. Don't let it run off the end.
5701 _minify_to_max(\$start);
5709 # If this is '-something', delete any spaces after the dash.
5710 $spec =~ s/\A-\s*\z/-/;
5712 # If the line is '$something', assume this is a scalar containing a
5714 # Set up for DB::eval() - evaluate in *user* context.
5715 if ( my ($var_name) = $spec =~ /\A(\$.*)/s ) {
5716 return _cmd_l_handle_var_name($var_name);
5718 # l name. Try to find a sub by that name.
5719 elsif ( ($subname) = $spec =~ /\A([\':A-Za-z_][\':\w]*(?:\[.*\])?)/s ) {
5720 return _cmd_l_handle_subname();
5723 elsif ( $spec !~ /\S/ ) {
5724 return _cmd_l_empty();
5726 # l [start]+number_of_lines
5727 elsif ( my ($new_start, $new_incr) = $spec =~ /\A(\d*)\+(\d*)\z/ ) {
5728 return _cmd_l_plus($new_start, $new_incr);
5730 # l start-stop or l start,stop
5731 elsif (my ($s, $e) = $spec =~ /^(?:(-?[\d\$\.]+)(?:[-,]([\d\$\.]+))?)?/ ) {
5732 return _cmd_l_range($spec, $line, $s, $e);
5739 my (undef, $line) = @_;
5741 return _cmd_l_main($line);
5744 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5746 To list breakpoints, the command has to look determine where all of them are
5747 first. It starts a C<%had_breakpoints>, which tells us what all files have
5748 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5749 magic source and breakpoint data structures) to the file, and then look
5750 through C<%dbline> for lines with breakpoints and/or actions, listing them
5751 out. We look through C<%postponed> not-yet-compiled subroutines that have
5752 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5753 that have breakpoints.
5755 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5759 sub _cmd_L_calc_arg {
5760 # If no argument, list everything. Pre-5.8.0 version always lists
5762 my $arg = shift || 'abw';
5763 if ($CommandSet ne '580')
5771 sub _cmd_L_calc_wanted_flags {
5772 my $arg = _cmd_L_calc_arg(shift);
5774 return (map { index($arg, $_) >= 0 ? 1 : 0 } qw(a b w));
5778 sub _cmd_L_handle_breakpoints {
5779 my ($handle_db_line) = @_;
5782 # Look in all the files with breakpoints...
5783 for my $file ( keys %had_breakpoints ) {
5785 # Temporary switch to this file.
5786 local *dbline = $main::{ '_<' . $file };
5788 # Set up to look through the whole file.
5790 my $was; # Flag: did we print something
5793 # For each line in the file ...
5794 for my $i (1 .. $max) {
5796 # We've got something on this line.
5797 if ( defined $dbline{$i} ) {
5799 # Print the header if we haven't.
5801 print {$OUT} "$file:\n";
5805 print {$OUT} " $i:\t", $dbline[$i];
5807 $handle_db_line->($dbline{$i});
5809 # Quit if the user hit interrupt.
5811 last BREAKPOINTS_SCAN;
5813 } ## end if (defined $dbline{$i...
5814 } ## end for my $i (1 .. $max)
5815 } ## end for my $file (keys %had_breakpoints)
5820 sub _cmd_L_handle_postponed_breakpoints {
5821 my ($handle_db_line) = @_;
5823 print {$OUT} "Postponed breakpoints in files:\n";
5826 for my $file ( keys %postponed_file ) {
5827 my $db = $postponed_file{$file};
5828 print {$OUT} " $file:\n";
5829 for my $line ( sort { $a <=> $b } keys %$db ) {
5830 print {$OUT} " $line:\n";
5832 $handle_db_line->($db->{$line});
5835 last POSTPONED_SCANS;
5839 last POSTPONED_SCANS;
5850 my ($action_wanted, $break_wanted, $watch_wanted) =
5851 _cmd_L_calc_wanted_flags(shift);
5853 my $handle_db_line = sub {
5856 my ( $stop, $action ) = split( /\0/, $l );
5858 if ($stop and $break_wanted) {
5859 print {$OUT} " break if (", $stop, ")\n"
5862 if ($action && $action_wanted) {
5863 print {$OUT} " action: ", $action, "\n"
5869 # Breaks and actions are found together, so we look in the same place
5871 if ( $break_wanted or $action_wanted ) {
5872 _cmd_L_handle_breakpoints($handle_db_line);
5875 # Look for breaks in not-yet-compiled subs:
5876 if ( %postponed and $break_wanted ) {
5877 print {$OUT} "Postponed breakpoints in subroutines:\n";
5880 for $subname ( keys %postponed ) {
5881 print {$OUT} " $subname\t$postponed{$subname}\n";
5886 } ## end if (%postponed and $break_wanted)
5888 # Find files that have not-yet-loaded breaks:
5889 my @have = map { # Combined keys
5890 keys %{ $postponed_file{$_} }
5891 } keys %postponed_file;
5893 # If there are any, list them.
5894 if ( @have and ( $break_wanted or $action_wanted ) ) {
5895 _cmd_L_handle_postponed_breakpoints($handle_db_line);
5896 } ## end if (@have and ($break_wanted...
5898 if ( %break_on_load and $break_wanted ) {
5899 print {$OUT} "Breakpoints on load:\n";
5900 BREAK_ON_LOAD: for my $filename ( keys %break_on_load ) {
5901 print {$OUT} " $filename\n";
5902 last BREAK_ON_LOAD if $signal;
5904 } ## end if (%break_on_load and...
5906 if ($watch_wanted and ( $trace & 2 )) {
5907 print {$OUT} "Watch-expressions:\n" if @to_watch;
5908 TO_WATCH: for my $expr (@to_watch) {
5909 print {$OUT} " $expr\n";
5910 last TO_WATCH if $signal;
5917 =head3 C<cmd_M> - list modules (command)
5919 Just call C<list_modules>.
5929 =head3 C<cmd_o> - options (command)
5931 If this is just C<o> by itself, we list the current settings via
5932 C<dump_option>. If there's a nonblank value following it, we pass that on to
5933 C<parse_options> for processing.
5939 my $opt = shift || ''; # opt[=val]
5941 # Nonblank. Try to parse and process.
5942 if ( $opt =~ /^(\S.*)/ ) {
5946 # Blank. List the current option settings.
5954 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5956 Advises the user that the O command has been renamed.
5961 print $OUT "The old O command is now the o command.\n"; # hint
5962 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5963 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5966 =head3 C<cmd_v> - view window (command)
5968 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5969 move back a few lines to list the selected line in context. Uses C<cmd_l>
5970 to do the actual listing after figuring out the range of line to request.
5974 use vars qw($preview);
5980 # Extract the line to list around. (Astute readers will have noted that
5981 # this pattern will match whether or not a numeric line is specified,
5982 # which means that we'll always enter this loop (though a non-numeric
5983 # argument results in no action at all)).
5984 if ( $line =~ /^(\d*)$/ ) {
5986 # Total number of lines to list (a windowful).
5987 $incr = $window - 1;
5989 # Set the start to the argument given (if there was one).
5992 # Back up by the context amount.
5995 # Put together a linespec that cmd_l will like.
5996 $line = $start . '-' . ( $start + $incr );
5999 cmd_l( 'l', $line );
6000 } ## end if ($line =~ /^(\d*)$/)
6003 =head3 C<cmd_w> - add a watch expression (command)
6005 The 5.8 version of this command adds a watch expression if one is specified;
6006 it does nothing if entered with no operands.
6008 We extract the expression, save it, evaluate it in the user's context, and
6009 save the value. We'll re-evaluate it each time the debugger passes a line,
6010 and will stop (see the code at the top of the command loop) if the value
6011 of any of the expressions changes.
6015 sub _add_watch_expr {
6019 push @to_watch, $expr;
6021 # Parameterize DB::eval and call it to get the expression's value
6022 # in the user's context. This version can handle expressions which
6023 # return a list value.
6025 # The &-call is here to ascertain the mutability of @_.
6026 my ($val) = join( ' ', &DB::eval);
6027 $val = ( defined $val ) ? "'$val'" : 'undef';
6029 # Save the current value of the expression.
6030 push @old_watch, $val;
6032 # We are now watching expressions.
6041 # Null expression if no arguments.
6042 my $expr = shift || '';
6044 # If expression is not null ...
6045 if ( $expr =~ /\A\S/ ) {
6046 _add_watch_expr($expr);
6047 } ## end if ($expr =~ /^(\S.*)/)
6049 # You have to give one to get one.
6051 print $OUT "Adding a watch-expression requires an expression\n"; # hint
6057 =head3 C<cmd_W> - delete watch expressions (command)
6059 This command accepts either a watch expression to be removed from the list
6060 of watch expressions, or C<*> to delete them all.
6062 If C<*> is specified, we simply empty the watch expression list and the
6063 watch expression value list. We also turn off the bit that says we've got
6066 If an expression (or partial expression) is specified, we pattern-match
6067 through the expressions and remove the ones that match. We also discard
6068 the corresponding values. If no watch expressions are left, we turn off
6069 the I<watching expressions> bit.
6075 my $expr = shift || '';
6078 if ( $expr eq '*' ) {
6083 print $OUT "Deleting all watch expressions ...\n";
6086 @to_watch = @old_watch = ();
6089 # Delete one of them.
6090 elsif ( $expr =~ /^(\S.*)/ ) {
6092 # Where we are in the list.
6095 # For each expression ...
6096 foreach (@to_watch) {
6097 my $val = $to_watch[$i_cnt];
6099 # Does this one match the command argument?
6100 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
6101 # Yes. Turn it off, and its value too.
6102 splice( @to_watch, $i_cnt, 1 );
6103 splice( @old_watch, $i_cnt, 1 );
6106 } ## end foreach (@to_watch)
6108 # We don't bother to turn watching off because
6109 # a) we don't want to stop calling watchfunction() if it exists
6110 # b) foreach over a null list doesn't do anything anyway
6112 } ## end elsif ($expr =~ /^(\S.*)/)
6114 # No command arguments entered.
6117 "Deleting a watch-expression requires an expression, or '*' for all\n"
6122 ### END of the API section
6124 =head1 SUPPORT ROUTINES
6126 These are general support routines that are used in a number of places
6127 throughout the debugger.
6131 save() saves the user's versions of globals that would mess us up in C<@saved>,
6132 and installs the versions we like better.
6138 # Save eval failure, command failure, extended OS error, output field
6139 # separator, input record separator, output record separator and
6140 # the warning setting.
6141 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
6143 $, = ""; # output field separator is null string
6144 $/ = "\n"; # input record separator is newline
6145 $\ = ""; # output record separator is null string
6146 $^W = 0; # warnings are off
6149 =head2 C<print_lineinfo> - show where we are now
6151 print_lineinfo prints whatever it is that it is handed; it prints it to the
6152 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
6153 us to feed line information to a slave editor without messing up the
6158 sub print_lineinfo {
6160 # Make the terminal sensible if we're not the primary debugger.
6161 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
6164 # $LINEINFO may be undef if $noTTY is set or some other issue.
6167 print {$LINEINFO} @_;
6169 } ## end sub print_lineinfo
6171 =head2 C<postponed_sub>
6173 Handles setting postponed breakpoints in subroutines once they're compiled.
6174 For breakpoints, we use C<DB::find_sub> to locate the source file and line
6175 range for the subroutine, then mark the file as having a breakpoint,
6176 temporarily switch the C<*dbline> glob over to the source file, and then
6177 search the given range of lines to find a breakable line. If we find one,
6178 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
6182 # The following takes its argument via $evalarg to preserve current @_
6186 # Get the subroutine name.
6187 my $subname = shift;
6189 # If this is a 'break +<n> if <condition>' ...
6190 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
6192 # If there's no offset, use '+0'.
6193 my $offset = $1 || 0;
6195 # find_sub's value is 'fullpath-filename:start-stop'. It's
6196 # possible that the filename might have colons in it too.
6197 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
6200 # We got the start line. Add the offset '+<n>' from
6201 # $postponed{subname}.
6204 # Switch to the file this sub is in, temporarily.
6205 local *dbline = $main::{ '_<' . $file };
6207 # No warnings, please.
6208 local $^W = 0; # != 0 is magical below
6210 # This file's got a breakpoint in it.
6211 $had_breakpoints{$file} |= 1;
6213 # Last line in file.
6216 # Search forward until we hit a breakable line or get to
6217 # the end of the file.
6218 ++$i until $dbline[$i] != 0 or $i >= $max;
6220 # Copy the breakpoint in and delete it from %postponed.
6221 $dbline{$i} = delete $postponed{$subname};
6224 # find_sub didn't find the sub.
6227 print $OUT "Subroutine $subname not found.\n";
6230 } ## end if ($postponed{$subname...
6231 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
6233 #print $OUT "In postponed_sub for '$subname'.\n";
6234 } ## end sub postponed_sub
6238 Called after each required file is compiled, but before it is executed;
6239 also called if the name of a just-compiled subroutine is a key of
6240 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
6241 etc.) into the just-compiled code.
6243 If this is a C<require>'d file, the incoming parameter is the glob
6244 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
6246 If it's a subroutine, the incoming parameter is the subroutine name.
6252 # If there's a break, process it.
6253 if ($ImmediateStop) {
6255 # Right, we've stopped. Turn it off.
6258 # Enter the command loop when DB::DB gets called.
6262 # If this is a subroutine, let postponed_sub() deal with it.
6263 if (ref(\$_[0]) ne 'GLOB') {
6264 return postponed_sub(@_);
6267 # Not a subroutine. Deal with the file.
6268 local *dbline = shift;
6269 my $filename = $dbline;
6270 $filename =~ s/^_<//;
6272 $signal = 1, print $OUT "'$filename' loaded...\n"
6273 if $break_on_load{$filename};
6274 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
6276 # Do we have any breakpoints to put in this file?
6277 return unless $postponed_file{$filename};
6279 # Yes. Mark this file as having breakpoints.
6280 $had_breakpoints{$filename} |= 1;
6282 # "Cannot be done: insufficient magic" - we can't just put the
6283 # breakpoints saved in %postponed_file into %dbline by assigning
6284 # the whole hash; we have to do it one item at a time for the
6285 # breakpoints to be set properly.
6286 #%dbline = %{$postponed_file{$filename}};
6288 # Set the breakpoints, one at a time.
6291 for $key ( keys %{ $postponed_file{$filename} } ) {
6293 # Stash the saved breakpoint into the current file's magic line array.
6294 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
6297 # This file's been compiled; discard the stored breakpoints.
6298 delete $postponed_file{$filename};
6300 } ## end sub postponed
6304 C<dumpit> is the debugger's wrapper around dumpvar.pl.
6306 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
6307 a reference to a variable (the thing to be dumped) as its input.
6309 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
6310 the currently-selected filehandle, thank you very much). The current
6311 values of the package globals C<$single> and C<$trace> are backed up in
6312 lexicals, and they are turned off (this keeps the debugger from trying
6313 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
6314 preserve its current value and it is set to zero to prevent entry/exit
6315 messages from printing, and C<$doret> is localized as well and set to -2 to
6316 prevent return values from being shown.
6318 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
6319 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
6320 installed version in C<@INC>, yours will be used instead. Possible security
6323 It then checks to see if the subroutine C<main::dumpValue> is now defined
6324 it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
6325 localizes the globals necessary for things to be sane when C<main::dumpValue()>
6326 is called, and picks up the variable to be dumped from the parameter list.
6328 It checks the package global C<%options> to see if there's a C<dumpDepth>
6329 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
6330 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
6331 structure: -1 means dump everything.
6333 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
6336 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
6337 and we then return to the caller.
6343 # Save the current output filehandle and switch to the one
6344 # passed in as the first parameter.
6345 my $savout = select(shift);
6347 # Save current settings of $single and $trace, and then turn them off.
6348 my $osingle = $single;
6349 my $otrace = $trace;
6350 $single = $trace = 0;
6352 # XXX Okay, what do $frame and $doret do, again?
6356 # Load dumpvar.pl unless we've already got the sub we need from it.
6357 unless ( defined &main::dumpValue ) {
6358 do 'dumpvar.pl' or die $@;
6361 # If the load succeeded (or we already had dumpvalue()), go ahead
6363 if ( defined &main::dumpValue ) {
6368 my $maxdepth = shift || $option{dumpDepth};
6369 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
6370 main::dumpValue( $v, $maxdepth );
6371 } ## end if (defined &main::dumpValue)
6373 # Oops, couldn't load dumpvar.pl.
6376 print $OUT "dumpvar.pl not available.\n";
6379 # Reset $single and $trace to their old values.
6383 # Restore the old filehandle.
6387 =head2 C<print_trace>
6389 C<print_trace>'s job is to print a stack trace. It does this via the
6390 C<dump_trace> routine, which actually does all the ferreting-out of the
6391 stack trace data. C<print_trace> takes care of formatting it nicely and
6392 printing it to the proper filehandle.
6400 The filehandle to print to.
6404 How many frames to skip before starting trace.
6408 How many frames to print.
6412 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
6416 The original comment below seems to be noting that the traceback may not be
6417 correct if this routine is called in a tied method.
6421 # Tied method do not create a context, so may get wrong message:
6427 # If this is going to a slave editor, but we're not the primary
6428 # debugger, reset it first.
6430 if $fh eq $LINEINFO # slave editor
6431 and $LINEINFO eq $OUT # normal output
6432 and $term_pid != $$; # not the primary
6434 # Collect the actual trace information to be formatted.
6435 # This is an array of hashes of subroutine call info.
6436 my @sub = dump_trace( $_[0] + 1, $_[1] );
6438 # Grab the "short report" flag from @_.
6439 my $short = $_[2]; # Print short report, next one for sub name
6441 # Run through the traceback info, format it, and print it.
6443 for my $i (0 .. $#sub) {
6445 # Drop out if the user has lost interest and hit control-C.
6448 # Set the separator so arrays print nice.
6451 # Grab and stringify the arguments if they are there.
6453 defined $sub[$i]{args}
6454 ? "(@{ $sub[$i]{args} })"
6457 # Shorten them up if $maxtrace says they're too long.
6458 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
6459 if length $args > $maxtrace;
6461 # Get the file name.
6462 my $file = $sub[$i]{file};
6464 # Put in a filename header if short is off.
6465 $file = $file eq '-e' ? $file : "file '$file'" unless $short;
6467 # Get the actual sub's name, and shorten to $maxtrace's requirement.
6468 $s = $sub[$i]{'sub'};
6469 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
6471 # Short report uses trimmed file and sub names.
6473 my $sub = @_ >= 4 ? $_[3] : $s;
6474 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
6475 } ## end if ($short)
6477 # Non-short report includes full names.
6479 print $fh "$sub[$i]{context} = $s$args"
6480 . " called from $file"
6481 . " line $sub[$i]{line}\n";
6483 } ## end for my $i (0 .. $#sub)
6484 } ## end sub print_trace
6486 =head2 dump_trace(skip[,count])
6488 Actually collect the traceback information available via C<caller()>. It does
6489 some filtering and cleanup of the data, but mostly it just collects it to
6490 make C<print_trace()>'s job easier.
6492 C<skip> defines the number of stack frames to be skipped, working backwards
6493 from the most current. C<count> determines the total number of frames to
6494 be returned; all of them (well, the first 10^9) are returned if C<count>
6497 This routine returns a list of hashes, from most-recent to least-recent
6498 stack frame. Each has the following keys and values:
6502 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
6504 =item * C<sub> - subroutine name, or C<eval> information
6506 =item * C<args> - undef, or a reference to an array of arguments
6508 =item * C<file> - the file in which this item was defined (if any)
6510 =item * C<line> - the line on which it was defined
6516 sub _dump_trace_calc_saved_single_arg
6518 my ($nothard, $arg) = @_;
6521 if ( not defined $arg ) { # undefined parameter
6525 elsif ( $nothard and tied $arg ) { # tied parameter
6528 elsif ( $nothard and $type = ref $arg ) { # reference
6529 return "ref($type)";
6531 else { # can be stringified
6533 "$arg"; # Safe to stringify now - should not call f().
6535 # Backslash any single-quotes or backslashes.
6538 # Single-quote it unless it's a number or a colon-separated
6541 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
6543 # Turn high-bit characters into meta-whatever.
6544 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
6546 # Turn control characters into ^-whatever.
6547 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
6553 sub _dump_trace_calc_save_args {
6557 map { _dump_trace_calc_saved_single_arg($nothard, $_) } @args
6563 # How many levels to skip.
6566 # How many levels to show. (1e9 is a cheap way of saying "all of them";
6567 # it's unlikely that we'll have more than a billion stack frames. If you
6568 # do, you've got an awfully big machine...)
6569 my $count = shift || 1e9;
6571 # We increment skip because caller(1) is the first level *back* from
6572 # the current one. Add $skip to the count of frames so we have a
6573 # simple stop criterion, counting from $skip to $count+$skip.
6577 # These variables are used to capture output from caller();
6578 my ( $p, $file, $line, $sub, $h, $context );
6580 my ( $e, $r, @sub, $args );
6582 # XXX Okay... why'd we do that?
6583 my $nothard = not $frame & 8;
6586 # Do not want to trace this.
6587 my $otrace = $trace;
6590 # Start out at the skip count.
6591 # If we haven't reached the number of frames requested, and caller() is
6592 # still returning something, stay in the loop. (If we pass the requested
6593 # number of stack frames, or we run out - caller() returns nothing - we
6595 # Up the stack frame index to go back one more level each time.
6599 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
6604 # Go through the arguments and save them for later.
6605 my $save_args = _dump_trace_calc_save_args($nothard);
6607 # If context is true, this is array (@)context.
6608 # If context is false, this is scalar ($) context.
6609 # If neither, context isn't defined. (This is apparently a 'can't
6611 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
6613 # if the sub has args ($h true), make an anonymous array of the
6615 $args = $h ? $save_args : undef;
6617 # remove trailing newline-whitespace-semicolon-end of line sequence
6618 # from the eval text, if any.
6619 $e =~ s/\n\s*\;\s*\Z// if $e;
6621 # Escape backslashed single-quotes again if necessary.
6622 $e =~ s/([\\\'])/\\$1/g if $e;
6624 # if the require flag is true, the eval text is from a require.
6626 $sub = "require '$e'";
6629 # if it's false, the eval text is really from an eval.
6630 elsif ( defined $r ) {
6634 # If the sub is '(eval)', this is a block eval, meaning we don't
6635 # know what the eval'ed text actually was.
6636 elsif ( $sub eq '(eval)' ) {
6637 $sub = "eval {...}";
6640 # Stick the collected information into @sub as an anonymous hash.
6644 context => $context,
6652 # Stop processing frames if the user hit control-C.
6654 } ## end for ($i = $skip ; $i < ...
6656 # Restore the trace value again.
6659 } ## end sub dump_trace
6663 C<action()> takes input provided as the argument to an add-action command,
6664 either pre- or post-, and makes sure it's a complete command. It doesn't do
6665 any fancy parsing; it just keeps reading input until it gets a string
6666 without a trailing backslash.
6673 while ( $action =~ s/\\$// ) {
6675 # We have a backslash on the end. Read more.
6677 } ## end while ($action =~ s/\\$//)
6679 # Return the assembled action.
6685 This routine mostly just packages up a regular expression to be used
6686 to check that the thing it's being matched against has properly-matched
6689 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
6690 speeds things up by only creating the qr//'ed expression once; if it's
6691 already defined, we don't try to define it again. A speed hack.
6695 use vars qw($balanced_brace_re);
6699 # I hate using globals!
6700 $balanced_brace_re ||= qr{
6703 (?> [^{}] + ) # Non-parens without backtracking
6705 (??{ $balanced_brace_re }) # Group with matching parens
6709 return $_[0] !~ m/$balanced_brace_re/;
6710 } ## end sub unbalanced
6714 C<gets()> is a primitive (very primitive) routine to read continuations.
6715 It was devised for reading continuations for actions.
6716 it just reads more input with C<readline()> and returns it.
6721 return DB::readline("cont: ");
6724 =head2 C<_db_system()> - handle calls to<system()> without messing up the debugger
6726 The C<system()> function assumes that it can just go ahead and use STDIN and
6727 STDOUT, but under the debugger, we want it to use the debugger's input and
6730 C<_db_system()> socks away the program's STDIN and STDOUT, and then substitutes
6731 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
6732 and then puts everything back again.
6738 # We save, change, then restore STDIN and STDOUT to avoid fork() since
6739 # some non-Unix systems can do system() but have problems with fork().
6740 open( SAVEIN, "<&STDIN" ) || db_warn("Can't save STDIN");
6741 open( SAVEOUT, ">&STDOUT" ) || db_warn("Can't save STDOUT");
6742 open( STDIN, "<&IN" ) || db_warn("Can't redirect STDIN");
6743 open( STDOUT, ">&OUT" ) || db_warn("Can't redirect STDOUT");
6745 # XXX: using csh or tcsh destroys sigint retvals!
6747 open( STDIN, "<&SAVEIN" ) || db_warn("Can't restore STDIN");
6748 open( STDOUT, ">&SAVEOUT" ) || db_warn("Can't restore STDOUT");
6752 # most of the $? crud was coping with broken cshisms
6754 db_warn( "(Command exited ", ( $? >> 8 ), ")\n" );
6758 "(Command died of SIG#",
6760 ( ( $? & 128 ) ? " -- core dumped" : "" ),
6769 *system = \&_db_system;
6771 =head1 TTY MANAGEMENT
6773 The subs here do some of the terminal management for multiple debuggers.
6777 Top-level function called when we want to set up a new terminal for use
6780 If the C<noTTY> debugger option was set, we'll either use the terminal
6781 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
6782 to find one. If we're a forked debugger, we call C<resetterm> to try to
6783 get a whole new terminal if we can.
6785 In either case, we set up the terminal next. If the C<ReadLine> option was
6786 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6787 the appropriate attributes. We then
6791 use vars qw($ornaments);
6792 use vars qw($rl_attribs);
6796 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6799 require Term::ReadLine;
6801 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6804 my ( $i, $o ) = split $tty, /,/;
6805 $o = $i unless defined $o;
6806 open( IN, "<$i" ) or die "Cannot open TTY '$i' for read: $!";
6807 open( OUT, ">$o" ) or die "Cannot open TTY '$o' for write: $!";
6813 # We don't have a TTY - try to find one via Term::Rendezvous.
6815 require Term::Rendezvous;
6817 # See if we have anything to pass to Term::Rendezvous.
6818 # Use $HOME/.perldbtty$$ if not.
6819 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6821 # Rendezvous and get the filehandles.
6822 my $term_rv = Term::Rendezvous->new( $rv );
6824 $OUT = $term_rv->OUT;
6825 } ## end else [ if ($tty)
6826 } ## end if ($notty)
6828 # We're a daughter debugger. Try to fork off another TTY.
6829 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6833 # If we shouldn't use Term::ReadLine, don't.
6835 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6838 # We're using Term::ReadLine. Get all the attributes for this terminal.
6840 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6842 $rl_attribs = $term->Attribs;
6843 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6844 if defined $rl_attribs->{basic_word_break_characters}
6845 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6846 $rl_attribs->{special_prefixes} = '$@&%';
6847 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6848 $rl_attribs->{completion_function} = \&db_complete;
6849 } ## end else [ if (!$rl)
6851 # Set up the LINEINFO filehandle.
6852 $LINEINFO = $OUT unless defined $LINEINFO;
6853 $lineinfo = $console unless defined $lineinfo;
6859 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6860 $term->SetHistory(@hist);
6863 # XXX Ornaments are turned on unconditionally, which is not
6864 # always a good thing.
6865 ornaments($ornaments) if defined $ornaments;
6867 } ## end sub setterm
6870 $histfile //= option_val("HistFile", undef);
6871 return unless defined $histfile;
6872 open my $fh, "<", $histfile or return;
6883 return unless defined $histfile;
6884 eval { require File::Path } or return;
6885 eval { require File::Basename } or return;
6886 File::Path::mkpath(File::Basename::dirname($histfile));
6887 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6888 $histsize //= option_val("HistSize",100);
6889 my @copy = grep { $_ ne '?' } @hist;
6890 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6891 for ($start .. $#copy) {
6892 print $fh "$copy[$_]\n";
6894 close $fh or die "Could not write '$histfile': $!";
6897 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6899 When the process being debugged forks, or the process invokes a command
6900 via C<system()> which starts a new debugger, we need to be able to get a new
6901 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6902 fight over the terminal, and you can never quite be sure who's going to get the
6903 input you're typing.
6905 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6906 is tasked with doing all the necessary operating system mojo to get a new
6907 TTY (and probably another window) and to direct the new debugger to read and
6910 The debugger provides C<get_fork_TTY> functions which work for TCP
6911 socket servers, X11, OS/2, and Mac OS X. Other systems are not
6912 supported. You are encouraged to write C<get_fork_TTY> functions which
6913 work for I<your> platform and contribute them.
6915 =head3 C<socket_get_fork_TTY>
6919 sub connect_remoteport {
6922 my $socket = IO::Socket::INET->new(
6924 PeerAddr => $remoteport,
6928 die "Unable to connect to remote host: $remoteport\n";
6933 sub socket_get_fork_TTY {
6934 $tty = $LINEINFO = $IN = $OUT = connect_remoteport();
6936 # Do I need to worry about setting $term?
6938 reset_IN_OUT( $IN, $OUT );
6942 =head3 C<xterm_get_fork_TTY>
6944 This function provides the C<get_fork_TTY> function for X11. If a
6945 program running under the debugger forks, a new <xterm> window is opened and
6946 the subsidiary debugger is directed there.
6948 The C<open()> call is of particular note here. We have the new C<xterm>
6949 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6950 command (which prints the device name of the TTY we'll want to use for input
6951 and output to STDOUT, then C<sleep> for a very long time, routing this output
6952 to file number 3. This way we can simply read from the <XT> filehandle (which
6953 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6955 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6960 sub xterm_get_fork_TTY {
6961 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6963 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6966 # Get the output from 'tty' and clean it up a little.
6970 $pidprompt = ''; # Shown anyway in titlebar
6972 # We need $term defined or we can not switch to the newly created xterm
6973 if ($tty ne '' && !defined $term) {
6974 require Term::ReadLine;
6976 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6979 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6982 # There's our new TTY.
6984 } ## end sub xterm_get_fork_TTY
6986 =head3 C<os2_get_fork_TTY>
6988 XXX It behooves an OS/2 expert to write the necessary documentation for this!
6992 # This example function resets $IN, $OUT itself
6994 sub os2_get_fork_TTY { # A simplification of the following (and works without):
6996 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6997 my %opt = ( title => "Daughter Perl debugger $pids $name",
6998 ($rl ? (read_by_key => 1) : ()) );
6999 require OS2::Process;
7000 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
7002 $pidprompt = ''; # Shown anyway in titlebar
7003 reset_IN_OUT($in, $out);
7005 return ''; # Indicate that reset_IN_OUT is called
7006 } ## end sub os2_get_fork_TTY
7008 =head3 C<macosx_get_fork_TTY>
7010 The Mac OS X version uses AppleScript to tell Terminal.app to create
7015 # Notes about Terminal.app's AppleScript support,
7016 # (aka things that might break in future OS versions).
7018 # The "do script" command doesn't return a reference to the new window
7019 # it creates, but since it appears frontmost and windows are enumerated
7020 # front to back, we can use "first window" === "window 1".
7022 # Since "do script" is implemented by supplying the argument (plus a
7023 # return character) as terminal input, there's a potential race condition
7024 # where the debugger could beat the shell to reading the command.
7025 # To prevent this, we wait for the screen to clear before proceeding.
7028 # There's no direct accessor for the tty device name, so we fiddle
7029 # with the window title options until it says what we want.
7032 # There _is_ a direct accessor for the tty device name, _and_ there's
7033 # a new possible component of the window title (the name of the settings
7034 # set). A separate version is needed.
7036 my @script_versions=
7038 ([237, <<'__LEOPARD__'],
7039 tell application "Terminal"
7040 do script "clear;exec sleep 100000"
7041 tell first tab of first window
7043 set custom title to "forked perl debugger"
7044 set title displays custom title to true
7045 repeat while (length of first paragraph of (get contents)) > 0
7053 [100, <<'__JAGUAR_TIGER__'],
7054 tell application "Terminal"
7055 do script "clear;exec sleep 100000"
7057 set title displays shell path to false
7058 set title displays window size to false
7059 set title displays file name to false
7060 set title displays device name to true
7061 set title displays custom title to true
7062 set custom title to ""
7063 copy "/dev/" & name to thetty
7064 set custom title to "forked perl debugger"
7065 repeat while (length of first paragraph of (get contents)) > 0
7075 sub macosx_get_fork_TTY
7077 my($version,$script,$pipe,$tty);
7079 return unless $version=$ENV{TERM_PROGRAM_VERSION};
7080 foreach my $entry (@script_versions) {
7081 if ($version>=$entry->[0]) {
7082 $script=$entry->[1];
7086 return unless defined($script);
7087 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script);
7088 $tty=readline($pipe);
7090 return unless defined($tty) && $tty =~ m(^/dev/);
7095 =head3 C<tmux_get_fork_TTY>
7097 Creates a split window for subprocesses when a process running under the
7098 perl debugger in Tmux forks.
7102 sub tmux_get_fork_TTY {
7103 return unless $ENV{TMUX};
7107 my $status = open $pipe, '-|', 'tmux', 'split-window',
7108 '-P', '-F', '#{pane_tty}', 'sleep 100000';
7120 if ( !defined $term ) {
7121 require Term::ReadLine;
7123 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
7126 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
7134 =head2 C<create_IN_OUT($flags)>
7136 Create a new pair of filehandles, pointing to a new TTY. If impossible,
7137 try to diagnose why.
7143 =item * 1 - Don't know how to create a new TTY.
7145 =item * 2 - Debugger has forked, but we can't get a new TTY.
7147 =item * 4 - standard debugger startup is happening.
7153 use vars qw($fork_TTY);
7155 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
7157 # If we know how to get a new TTY, do it! $in will have
7158 # the TTY name if get_fork_TTY works.
7159 my $in = get_fork_TTY(@_) if defined &get_fork_TTY;
7161 # It used to be that
7162 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
7164 if ( not defined $in ) {
7167 # We don't know how.
7168 print_help(<<EOP) if $why == 1;
7169 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
7173 print_help(<<EOP) if $why == 2;
7174 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
7175 This may be an asynchronous session, so the parent debugger may be active.
7178 # Note that both debuggers are fighting over the same input.
7179 print_help(<<EOP) if $why != 4;
7180 Since two debuggers fight for the same TTY, input is severely entangled.
7184 I know how to switch the output to a different window in xterms, OS/2
7185 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
7186 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
7187 B<DB::get_fork_TTY()> returning this.
7189 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
7190 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
7193 } ## end if (not defined $in)
7194 elsif ( $in ne '' ) {
7198 $console = ''; # Indicate no need to open-from-the-console
7201 } ## end sub create_IN_OUT
7205 Handles rejiggering the prompt when we've forked off a new debugger.
7207 If the new debugger happened because of a C<system()> that invoked a
7208 program under the debugger, the arrow between the old pid and the new
7209 in the prompt has I<two> dashes instead of one.
7211 We take the current list of pids and add this one to the end. If there
7212 isn't any list yet, we make one up out of the initial pid associated with
7213 the terminal and our new pid, sticking an arrow (either one-dashed or
7214 two dashed) in between them.
7216 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
7217 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
7222 sub resetterm { # We forked, so we need a different TTY
7224 # Needs to be passed to create_IN_OUT() as well.
7227 # resetterm(2): got in here because of a system() starting a debugger.
7228 # resetterm(1): just forked.
7229 my $systemed = $in > 1 ? '-' : '';
7231 # If there's already a list of pids, add this to the end.
7233 $pids =~ s/\]/$systemed->$$]/;
7236 # No pid list. Time to make one.
7238 $pids = "[$term_pid->$$]";
7241 # The prompt we're going to be using for this debugger.
7244 # We now 0wnz this terminal.
7247 # Just return if we're not supposed to try to create a new TTY.
7248 return unless $CreateTTY & $in;
7250 # Try to create a new IN/OUT pair.
7252 } ## end sub resetterm
7256 First, we handle stuff in the typeahead buffer. If there is any, we shift off
7257 the next line, print a message saying we got it, add it to the terminal
7258 history (if possible), and return it.
7260 If there's nothing in the typeahead buffer, check the command filehandle stack.
7261 If there are any filehandles there, read from the last one, and return the line
7262 if we got one. If not, we pop the filehandle off and close it, and try the
7263 next one up the stack.
7265 If we've emptied the filehandle stack, we check to see if we've got a socket
7266 open, and we read that and return it if we do. If we don't, we just call the
7267 core C<readline()> and return its value.
7273 # Localize to prevent it from being smashed in the program being debugged.
7276 # If there are stacked filehandles to read from ...
7277 # (Handle it before the typeahead, because we may call source/etc. from
7281 # Read from the last one in the stack.
7282 my $line = CORE::readline( $cmdfhs[-1] );
7284 # If we got a line ...
7286 ? ( print $OUT ">> $line" and return $line ) # Echo and return
7287 : close pop @cmdfhs; # Pop and close
7288 } ## end while (@cmdfhs)
7290 # Pull a line out of the typeahead if there's stuff there.
7293 # How many lines left.
7294 my $left = @typeahead;
7296 # Get the next line.
7297 my $got = shift @typeahead;
7299 # Print a message saying we got input from the typeahead.
7301 print $OUT "auto(-$left)", shift, $got, "\n";
7303 # Add it to the terminal history (if possible).
7304 $term->AddHistory($got)
7306 and defined $term->Features->{addHistory};
7308 } ## end if (@typeahead)
7310 # We really need to read some input. Turn off entry/exit trace and
7311 # return value printing.
7315 # Nothing on the filehandle stack. Socket?
7316 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
7318 # Send anything we have to send.
7319 $OUT->write( join( '', @_ ) );
7321 # Receive anything there is to receive.
7326 while ($first_time or (length($buf) && ($stuff .= $buf) !~ /\n/))
7329 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
7330 # XXX Don't know. You tell me.
7335 } ## end if (ref $OUT and UNIVERSAL::isa...
7337 # No socket. Just read from the terminal.
7339 return $term->readline(@_);
7341 } ## end sub readline
7343 =head1 OPTIONS SUPPORT ROUTINES
7345 These routines handle listing and setting option values.
7347 =head2 C<dump_option> - list the current value of an option setting
7349 This routine uses C<option_val> to look up the value for an option.
7350 It cleans up escaped single-quotes and then displays the option and
7356 my ( $opt, $val ) = @_;
7357 $val = option_val( $opt, 'N/A' );
7358 $val =~ s/([\\\'])/\\$1/g;
7359 printf $OUT "%20s = '%s'\n", $opt, $val;
7360 } ## end sub dump_option
7362 sub options2remember {
7363 foreach my $k (@RememberOnROptions) {
7364 $option{$k} = option_val( $k, 'N/A' );
7369 =head2 C<option_val> - find the current value of an option
7371 This can't just be a simple hash lookup because of the indirect way that
7372 the option values are stored. Some are retrieved by calling a subroutine,
7373 some are just variables.
7375 You must supply a default value to be used in case the option isn't set.
7380 my ( $opt, $default ) = @_;
7383 # Does this option exist, and is it a variable?
7384 # If so, retrieve the value via the value in %optionVars.
7385 if ( defined $optionVars{$opt}
7386 and defined ${ $optionVars{$opt} } )
7388 $val = ${ $optionVars{$opt} };
7391 # Does this option exist, and it's a subroutine?
7392 # If so, call the subroutine via the ref in %optionAction
7393 # and capture the value.
7394 elsif ( defined $optionAction{$opt}
7395 and defined &{ $optionAction{$opt} } )
7397 $val = &{ $optionAction{$opt} }();
7400 # If there's an action or variable for the supplied option,
7401 # but no value was set, use the default.
7402 elsif (defined $optionAction{$opt} and not defined $option{$opt}
7403 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
7408 # Otherwise, do the simple hash lookup.
7410 $val = $option{$opt};
7413 # If the value isn't defined, use the default.
7414 # Then return whatever the value is.
7415 $val = $default unless defined $val;
7417 } ## end sub option_val
7419 =head2 C<parse_options>
7421 Handles the parsing and execution of option setting/displaying commands.
7423 An option entered by itself is assumed to be I<set me to 1> (the default value)
7424 if the option is a boolean one. If not, the user is prompted to enter a valid
7425 value or to query the current value (via C<option? >).
7427 If C<option=value> is entered, we try to extract a quoted string from the
7428 value (if it is quoted). If it's not, we just use the whole value as-is.
7430 We load any modules required to service this option, and then we set it: if
7431 it just gets stuck in a variable, we do that; if there's a subroutine to
7432 handle setting the option, we call that.
7434 Finally, if we're running in interactive mode, we display the effect of the
7435 user's command back to the terminal, skipping this if we're setting things
7436 during initialization.
7446 # These options need a value. Don't allow them to be clobbered by accident.
7447 my %opt_needs_val = map { ( $_ => 1 ) } qw{
7448 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
7449 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
7452 while (length($s)) {
7455 # Clean off excess leading whitespace.
7456 $s =~ s/^\s+// && next;
7458 # Options are always all word characters, followed by a non-word
7460 if ($s !~ s/^(\w+)(\W?)//) {
7461 print {$OUT} "Invalid option '$s'\n";
7464 my ( $opt, $sep ) = ( $1, $2 );
7466 # Make sure that such an option exists.
7467 my $matches = ( grep { /^\Q$opt/ && ( $option = $_ ) } @options )
7468 || ( grep { /^\Q$opt/i && ( $option = $_ ) } @options );
7471 print {$OUT} "Unknown option '$opt'\n";
7475 print {$OUT} "Ambiguous option '$opt'\n";
7480 # '?' as separator means query, but must have whitespace after it.
7481 if ( "?" eq $sep ) {
7483 print {$OUT} "Option query '$opt?' followed by non-space '$s'\n" ;
7488 #&dump_option($opt);
7489 } ## end if ("?" eq $sep)
7491 # Separator is whitespace (or just a carriage return).
7492 # They're going for a default, which we assume is 1.
7493 elsif ( $sep !~ /\S/ ) {
7495 $val = "1"; # this is an evil default; make 'em set it!
7498 # Separator is =. Trying to set a value.
7499 elsif ( $sep eq "=" ) {
7501 # If quoted, extract a quoted string.
7502 if ($s =~ s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
7504 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
7507 # Not quoted. Use the whole thing. Warn about 'option='.
7511 print OUT qq(Option better cleared using $opt=""\n)
7513 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
7515 } ## end elsif ($sep eq "=")
7517 # "Quoted" with [], <>, or {}.
7518 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
7520 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
7521 $s =~ s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
7522 or print( $OUT "Unclosed option value '$opt$sep$_'\n" ), last;
7523 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
7524 } ## end else [ if ("?" eq $sep)
7526 # Exclude non-booleans from getting set to 1 by default.
7527 if ( $opt_needs_val{$option} && $val_defaulted ) {
7528 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
7530 "Option '$opt' is non-boolean. Use '$cmd $option=VAL' to set, '$cmd $option?' to query\n";
7532 } ## end if ($opt_needs_val{$option...
7534 # Save the option value.
7535 $option{$option} = $val if defined $val;
7537 # Load any module that this option requires.
7538 if ( defined($optionRequire{$option}) && defined($val) ) {
7542 require '$optionRequire{$option}';
7544 } || die $@ # XXX: shouldn't happen
7548 # Stick it in the proper variable if it goes in a variable.
7549 if (defined($optionVars{$option}) && defined($val)) {
7550 ${ $optionVars{$option} } = $val;
7553 # Call the appropriate sub if it gets set via sub.
7554 if (defined($optionAction{$option})
7555 && defined (&{ $optionAction{$option} })
7558 &{ $optionAction{$option} }($val);
7561 # Not initialization - echo the value we set it to.
7562 dump_option($option) if ($OUT ne \*STDERR);
7563 } ## end while (length)
7564 } ## end sub parse_options
7566 =head1 RESTART SUPPORT
7568 These routines are used to store (and restore) lists of items in environment
7569 variables during a restart.
7573 Set_list packages up items to be stored in a set of environment variables
7574 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
7575 the values). Values outside the standard ASCII charset are stored by encoding
7576 then as hexadecimal values.
7581 my ( $stem, @list ) = @_;
7584 # VAR_n: how many we have. Scalar assignment gets the number of items.
7585 $ENV{"${stem}_n"} = @list;
7587 # Grab each item in the list, escape the backslashes, encode the non-ASCII
7588 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
7589 for my $i ( 0 .. $#list ) {
7591 $val =~ s/\\/\\\\/g;
7592 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg;
7593 $ENV{"${stem}_$i"} = $val;
7594 } ## end for $i (0 .. $#list)
7595 } ## end sub set_list
7599 Reverse the set_list operation: grab VAR_n to see how many we should be getting
7600 back, and then pull VAR_0, VAR_1. etc. back out.
7607 my $n = delete $ENV{"${stem}_n"};
7609 for my $i ( 0 .. $n - 1 ) {
7610 $val = delete $ENV{"${stem}_$i"};
7611 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
7615 } ## end sub get_list
7617 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
7621 The C<catch()> subroutine is the essence of fast and low-impact. We simply
7622 set an already-existing global scalar variable to a constant value. This
7623 avoids allocating any memory possibly in the middle of something that will
7624 get all confused if we do, particularly under I<unsafe signals>.
7630 return; # Put nothing on the stack - malloc/free land!
7635 C<warn> emits a warning, by joining together its arguments and printing
7636 them, with couple of fillips.
7638 If the composited message I<doesn't> end with a newline, we automatically
7639 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
7640 to be set to the filehandle to be used to output warnings; it makes no
7641 assumptions about what filehandles are available.
7646 my ($msg) = join( "", @_ );
7647 $msg .= ": $!\n" unless $msg =~ /\n$/;
7654 =head1 INITIALIZATION TTY SUPPORT
7656 =head2 C<reset_IN_OUT>
7658 This routine handles restoring the debugger's input and output filehandles
7659 after we've tried and failed to move them elsewhere. In addition, it assigns
7660 the debugger's output filehandle to $LINEINFO if it was already open there.
7665 my $switch_li = $LINEINFO eq $OUT;
7667 # If there's a term and it's able to get a new tty, try to get one.
7668 if ( $term and $term->Features->{newTTY} ) {
7669 ( $IN, $OUT ) = ( shift, shift );
7670 $term->newTTY( $IN, $OUT );
7673 # This term can't get a new tty now. Better luck later.
7675 _db_warn("Too late to set IN/OUT filehandles, enabled on next 'R'!\n");
7678 # Set the filehndles up as they were.
7680 ( $IN, $OUT ) = ( shift, shift );
7683 # Unbuffer the output filehandle.
7686 # Point LINEINFO to the same output filehandle if it was there before.
7687 $LINEINFO = $OUT if $switch_li;
7688 } ## end sub reset_IN_OUT
7690 =head1 OPTION SUPPORT ROUTINES
7692 The following routines are used to process some of the more complicated
7697 Sets the input and output filehandles to the specified files or pipes.
7698 If the terminal supports switching, we go ahead and do it. If not, and
7699 there's already a terminal in place, we save the information to take effect
7702 If there's no terminal yet (for instance, during debugger initialization),
7703 we go ahead and set C<$console> and C<$tty> to the file indicated.
7709 if ( @_ and $term and $term->Features->{newTTY} ) {
7711 # This terminal supports switching to a new TTY.
7712 # Can be a list of two files, or on string containing both names,
7714 # XXX Should this perhaps be an assignment from @_?
7715 my ( $in, $out ) = shift;
7718 # Split list apart if supplied.
7719 ( $in, $out ) = split /,/, $in, 2;
7723 # Use the same file for both input and output.
7727 # Open file onto the debugger's filehandles, if you can.
7728 open IN, $in or die "cannot open '$in' for read: $!";
7729 open OUT, ">$out" or die "cannot open '$out' for write: $!";
7731 # Swap to the new filehandles.
7732 reset_IN_OUT( \*IN, \*OUT );
7734 # Save the setting for later.
7736 } ## end if (@_ and $term and $term...
7738 # Terminal doesn't support new TTY, or doesn't support readline.
7739 # Can't do it now, try restarting.
7741 _db_warn("Too late to set TTY, enabled on next 'R'!\n");
7744 # Useful if done through PERLDB_OPTS:
7745 $console = $tty = shift if @_;
7747 # Return whatever the TTY is.
7753 Sets the C<$notty> global, controlling whether or not the debugger tries to
7754 get a terminal to read from. If called after a terminal is already in place,
7755 we save the value to use it if we're restarted.
7761 _db_warn("Too late to set noTTY, enabled on next 'R'!\n") if @_;
7763 $notty = shift if @_;
7769 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
7770 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
7771 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
7772 the value in case a restart is done so we can change it then.
7778 _db_warn("Too late to set ReadLine, enabled on next 'R'!\n") if @_;
7782 } ## end sub ReadLine
7784 =head2 C<RemotePort>
7786 Sets the port that the debugger will try to connect to when starting up.
7787 If the terminal's already been set up, we can't do it, but we remember the
7788 setting in case the user does a restart.
7794 _db_warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
7796 $remoteport = shift if @_;
7798 } ## end sub RemotePort
7802 Checks with the terminal to see if C<Tk> is running, and returns true or
7803 false. Returns false if the current terminal doesn't support C<readline>.
7808 if ( ${ $term->Features }{tkRunning} ) {
7809 return $term->tkRunning(@_);
7813 print $OUT "tkRunning not supported by current ReadLine package.\n";
7816 } ## end sub tkRunning
7820 Sets nonstop mode. If a terminal's already been set up, it's too late; the
7821 debugger remembers the setting in case you restart, though.
7827 _db_warn("Too late to set up NonStop mode, enabled on next 'R'!\n")
7830 $runnonstop = shift if @_;
7832 } ## end sub NonStop
7836 _db_warn("Some flag changes could not take effect until next 'R'!\n")
7839 $^P = parse_DollarCaretP_flags(shift) if @_;
7840 expand_DollarCaretP_flags($^P);
7845 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
7853 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
7860 Sets the shell escape command, and generates a printable copy to be used
7867 # If we got an argument, meta-quote it, and add '\b' if it
7868 # ends in a word character.
7870 $sh = quotemeta shift;
7871 $sh .= "\\b" if $sh =~ /\w$/;
7874 # Generate the printable version for the help:
7875 $psh = $sh; # copy it
7876 $psh =~ s/\\b$//; # Take off trailing \b if any
7877 $psh =~ s/\\(.)/$1/g; # De-escape
7878 $psh; # return the printable version
7879 } ## end sub shellBang
7883 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7884 was passed as the argument. (This means you can't override the terminal's
7890 if ( defined $term ) {
7892 # We don't want to show warning backtraces, but we do want die() ones.
7893 local $warnLevel = 0;
7894 local $dieLevel = 1;
7896 # No ornaments if the terminal doesn't support them.
7897 if (not $term->Features->{ornaments}) {
7901 return (eval { $term->ornaments(@_) } || '');
7904 # Use what was passed in if we can't determine it ourselves.
7911 } ## end sub ornaments
7913 =head2 C<recallCommand>
7915 Sets the recall command, and builds a printable version which will appear in
7922 # If there is input, metaquote it. Add '\b' if it ends with a word
7925 $rc = quotemeta shift;
7926 $rc .= "\\b" if $rc =~ /\w$/;
7929 # Build it into a printable version.
7930 $prc = $rc; # Copy it
7931 $prc =~ s/\\b$//; # Remove trailing \b
7932 $prc =~ s/\\(.)/$1/g; # Remove escapes
7933 return $prc; # Return the printable version
7934 } ## end sub recallCommand
7936 =head2 C<LineInfo> - where the line number information goes
7938 Called with no arguments, returns the file or pipe that line info should go to.
7940 Called with an argument (a file or a pipe), it opens that onto the
7941 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7942 file or pipe again to the caller.
7950 # If this is a valid "thing to be opened for output", tack a
7951 # '>' onto the front.
7952 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7954 # If this is a pipe, the stream points to a slave editor.
7955 $slave_editor = ( $stream =~ /^\|/ );
7957 my $new_lineinfo_fh;
7958 # Open it up and unbuffer it.
7959 open ($new_lineinfo_fh , $stream )
7960 or _db_warn("Cannot open '$stream' for write");
7961 $LINEINFO = $new_lineinfo_fh;
7962 _autoflush($LINEINFO);
7966 } ## end sub LineInfo
7968 =head1 COMMAND SUPPORT ROUTINES
7970 These subroutines provide functionality for various commands.
7972 =head2 C<list_modules>
7974 For the C<M> command: list modules loaded and their versions.
7975 Essentially just runs through the keys in %INC, picks each package's
7976 C<$VERSION> variable, gets the file name, and formats the information
7981 sub list_modules { # versions
7985 # keys are the "as-loaded" name, values are the fully-qualified path
7986 # to the file itself.
7988 $file = $_; # get the module name
7989 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
7990 s,/,::,g; # change '/' to '::'
7991 s/^perl5db$/DB/; # Special case: debugger
7992 # moves to package DB
7993 s/^Term::ReadLine::readline$/readline/; # simplify readline
7995 # If the package has a $VERSION package global (as all good packages
7996 # should!) decode it and save as partial message.
7997 my $pkg_version = do { no strict 'refs'; ${ $_ . '::VERSION' } };
7998 if ( defined $pkg_version ) {
7999 $version{$file} = "$pkg_version from ";
8002 # Finish up the message with the file the package came from.
8003 $version{$file} .= $INC{$file};
8004 } ## end for (keys %INC)
8006 # Hey, dumpit() formats a hash nicely, so why not use it?
8007 dumpit( $OUT, \%version );
8008 } ## end sub list_modules
8012 Sets up the monster string used to format and print the help.
8014 =head3 HELP MESSAGE FORMAT
8016 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
8017 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
8018 easy to parse and portable, but which still allows the help to be a little
8019 nicer than just plain text.
8021 Essentially, you define the command name (usually marked up with C<< B<> >>
8022 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
8023 newline. The descriptive text can also be marked up in the same way. If you
8024 need to continue the descriptive text to another line, start that line with
8025 just tabs and then enter the marked-up text.
8027 If you are modifying the help text, I<be careful>. The help-string parser is
8028 not very sophisticated, and if you don't follow these rules it will mangle the
8029 help beyond hope until you fix the string.
8033 use vars qw($pre580_help);
8034 use vars qw($pre580_summary);
8038 # XXX: make sure there are tabs between the command and explanation,
8039 # or print_help will screw up your formatting if you have
8040 # eeevil ornaments enabled. This is an insane mess.
8043 Help is currently only available for the new 5.8 command set.
8044 No help is available for the old command set.
8045 We assume you know what you're doing if you switch to it.
8048 B<s> [I<expr>] Single step [in I<expr>].
8049 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
8050 <B<CR>> Repeat last B<n> or B<s> command.
8051 B<r> Return from current subroutine.
8052 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
8053 at the specified position.
8054 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
8055 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
8056 B<l> I<line> List single I<line>.
8057 B<l> I<subname> List first window of lines from subroutine.
8058 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
8059 B<l> List next window of lines.
8060 B<-> List previous window of lines.
8061 B<v> [I<line>] View window around I<line>.
8062 B<.> Return to the executed line.
8063 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
8064 I<filename> may be either the full name of the file, or a regular
8065 expression matching the full file name:
8066 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
8067 Evals (with saved bodies) are considered to be filenames:
8068 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
8069 (in the order of execution).
8070 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
8071 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
8072 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
8073 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
8074 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth).
8075 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
8076 B<b> Sets breakpoint on current line)
8077 B<b> [I<line>] [I<condition>]
8078 Set breakpoint; I<line> defaults to the current execution line;
8079 I<condition> breaks if it evaluates to true, defaults to '1'.
8080 B<b> I<subname> [I<condition>]
8081 Set breakpoint at first line of subroutine.
8082 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
8083 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
8084 B<b> B<postpone> I<subname> [I<condition>]
8085 Set breakpoint at first line of subroutine after
8087 B<b> B<compile> I<subname>
8088 Stop after the subroutine is compiled.
8089 B<B> [I<line>] Delete the breakpoint for I<line>.
8090 B<B> I<*> Delete all breakpoints.
8091 B<a> [I<line>] I<command>
8092 Set an action to be done before the I<line> is executed;
8093 I<line> defaults to the current execution line.
8094 Sequence is: check for breakpoint/watchpoint, print line
8095 if necessary, do action, prompt user if necessary,
8098 B<A> [I<line>] Delete the action for I<line>.
8099 B<A> I<*> Delete all actions.
8100 B<w> I<expr> Add a global watch-expression.
8102 B<W> I<expr> Delete a global watch-expression.
8103 B<W> I<*> Delete all watch-expressions.
8104 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
8105 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
8106 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
8107 B<x> I<expr> Evals expression in list context, dumps the result.
8108 B<m> I<expr> Evals expression in list context, prints methods callable
8109 on the first element of the result.
8110 B<m> I<class> Prints methods callable via the given class.
8111 B<M> Show versions of loaded modules.
8112 B<i> I<class> Prints nested parents of given class.
8113 B<e> Display current thread id.
8114 B<E> Display all thread ids the current one will be identified: <n>.
8115 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8117 B<<> ? List Perl commands to run before each prompt.
8118 B<<> I<expr> Define Perl command to run before each prompt.
8119 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
8120 B<< *> Delete the list of perl commands to run before each prompt.
8121 B<>> ? List Perl commands to run after each prompt.
8122 B<>> I<expr> Define Perl command to run after each prompt.
8123 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
8124 B<>>B< *> Delete the list of Perl commands to run after each prompt.
8125 B<{> I<db_command> Define debugger command to run before each prompt.
8126 B<{> ? List debugger commands to run before each prompt.
8127 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
8128 B<{ *> Delete the list of debugger commands to run before each prompt.
8129 B<$prc> I<number> Redo a previous command (default previous command).
8130 B<$prc> I<-number> Redo number'th-to-last command.
8131 B<$prc> I<pattern> Redo last command that started with I<pattern>.
8132 See 'B<O> I<recallCommand>' too.
8133 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
8138 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
8140 See 'B<O> I<shellBang>' too.
8141 B<source> I<file> Execute I<file> containing debugger commands (may nest).
8142 B<save> I<file> Save current debugger session (actual history) to I<file>.
8143 B<rerun> Rerun session to current position.
8144 B<rerun> I<n> Rerun session to numbered command.
8145 B<rerun> I<-n> Rerun session to number'th-to-last command.
8146 B<H> I<-number> Display last number commands (default all).
8147 B<H> I<*> Delete complete history.
8148 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
8149 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
8150 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarily select()ed as well.
8151 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
8152 I<command> Execute as a perl statement in current package.
8153 B<R> Pure-man-restart of debugger, some of debugger state
8154 and command-line options may be lost.
8155 Currently the following settings are preserved:
8156 history, breakpoints and actions, debugger B<O>ptions
8157 and the following command-line options: I<-w>, I<-I>, I<-e>.
8159 B<o> [I<opt>] ... Set boolean option to true
8160 B<o> [I<opt>B<?>] Query options
8161 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
8162 Set options. Use quotes if spaces in value.
8163 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
8164 I<pager> program for output of \"|cmd\";
8165 I<tkRunning> run Tk while prompting (with ReadLine);
8166 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
8167 I<inhibit_exit> Allows stepping off the end of the script.
8168 I<ImmediateStop> Debugger should stop as early as possible.
8169 I<RemotePort> Remote hostname:port for remote debugging
8170 The following options affect what happens with B<V>, B<X>, and B<x> commands:
8171 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
8172 I<compactDump>, I<veryCompact> change style of array and hash dump;
8173 I<globPrint> whether to print contents of globs;
8174 I<DumpDBFiles> dump arrays holding debugged files;
8175 I<DumpPackages> dump symbol tables of packages;
8176 I<DumpReused> dump contents of \"reused\" addresses;
8177 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
8178 I<bareStringify> Do not print the overload-stringified value;
8179 Other options include:
8180 I<PrintRet> affects printing of return value after B<r> command,
8181 I<frame> affects printing messages on subroutine entry/exit.
8182 I<AutoTrace> affects printing messages on possible breaking points.
8183 I<maxTraceLen> gives max length of evals/args listed in stack trace.
8184 I<ornaments> affects screen appearance of the command line.
8185 I<CreateTTY> bits control attempts to create a new TTY on events:
8186 1: on fork() 2: debugger is started inside debugger
8188 During startup options are initialized from \$ENV{PERLDB_OPTS}.
8189 You can put additional initialization options I<TTY>, I<noTTY>,
8190 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
8191 B<R> after you set them).
8193 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
8194 B<h> Summary of debugger commands.
8195 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
8196 B<h h> Long help for debugger commands
8197 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
8198 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
8199 Set B<\$DB::doccmd> to change viewer.
8201 Type '|h h' for a paged display if this was too hard to read.
8203 "; # Fix balance of vi % matching: }}}}
8205 # note: tabs in the following section are not-so-helpful
8206 $summary = <<"END_SUM";
8207 I<List/search source lines:> I<Control script execution:>
8208 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
8209 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
8210 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
8211 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
8212 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
8213 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
8214 I<Debugger controls:> B<L> List break/watch/actions
8215 B<o> [...] Set debugger options B<t> [I<n>] [I<expr>] Toggle trace [max depth] ][trace expr]
8216 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
8217 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
8218 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
8219 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
8220 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
8221 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
8222 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
8223 B<q> or B<^D> Quit B<R> Attempt a restart
8224 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
8225 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
8226 B<p> I<expr> Print expression (uses script's current package).
8227 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
8228 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
8229 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
8230 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8231 B<e> Display thread id B<E> Display all thread ids.
8232 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
8235 # ')}}; # Fix balance of vi % matching
8237 # and this is really numb...
8240 B<s> [I<expr>] Single step [in I<expr>].
8241 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
8242 B<CR>> Repeat last B<n> or B<s> command.
8243 B<r> Return from current subroutine.
8244 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
8245 at the specified position.
8246 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
8247 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
8248 B<l> I<line> List single I<line>.
8249 B<l> I<subname> List first window of lines from subroutine.
8250 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
8251 B<l> List next window of lines.
8252 B<-> List previous window of lines.
8253 B<w> [I<line>] List window around I<line>.
8254 B<.> Return to the executed line.
8255 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
8256 I<filename> may be either the full name of the file, or a regular
8257 expression matching the full file name:
8258 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
8259 Evals (with saved bodies) are considered to be filenames:
8260 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
8261 (in the order of execution).
8262 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
8263 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
8264 B<L> List all breakpoints and actions.
8265 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
8266 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth) .
8267 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
8268 B<b> [I<line>] [I<condition>]
8269 Set breakpoint; I<line> defaults to the current execution line;
8270 I<condition> breaks if it evaluates to true, defaults to '1'.
8271 B<b> I<subname> [I<condition>]
8272 Set breakpoint at first line of subroutine.
8273 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
8274 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
8275 B<b> B<postpone> I<subname> [I<condition>]
8276 Set breakpoint at first line of subroutine after
8278 B<b> B<compile> I<subname>
8279 Stop after the subroutine is compiled.
8280 B<d> [I<line>] Delete the breakpoint for I<line>.
8281 B<D> Delete all breakpoints.
8282 B<a> [I<line>] I<command>
8283 Set an action to be done before the I<line> is executed;
8284 I<line> defaults to the current execution line.
8285 Sequence is: check for breakpoint/watchpoint, print line
8286 if necessary, do action, prompt user if necessary,
8288 B<a> [I<line>] Delete the action for I<line>.
8289 B<A> Delete all actions.
8290 B<W> I<expr> Add a global watch-expression.
8291 B<W> Delete all watch-expressions.
8292 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
8293 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
8294 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
8295 B<x> I<expr> Evals expression in list context, dumps the result.
8296 B<m> I<expr> Evals expression in list context, prints methods callable
8297 on the first element of the result.
8298 B<m> I<class> Prints methods callable via the given class.
8300 B<<> ? List Perl commands to run before each prompt.
8301 B<<> I<expr> Define Perl command to run before each prompt.
8302 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
8303 B<>> ? List Perl commands to run after each prompt.
8304 B<>> I<expr> Define Perl command to run after each prompt.
8305 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
8306 B<{> I<db_command> Define debugger command to run before each prompt.
8307 B<{> ? List debugger commands to run before each prompt.
8308 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
8309 B<$prc> I<number> Redo a previous command (default previous command).
8310 B<$prc> I<-number> Redo number'th-to-last command.
8311 B<$prc> I<pattern> Redo last command that started with I<pattern>.
8312 See 'B<O> I<recallCommand>' too.
8313 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
8318 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
8320 See 'B<O> I<shellBang>' too.
8321 B<source> I<file> Execute I<file> containing debugger commands (may nest).
8322 B<H> I<-number> Display last number commands (default all).
8323 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
8324 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
8325 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
8326 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
8327 I<command> Execute as a perl statement in current package.
8328 B<v> Show versions of loaded modules.
8329 B<R> Pure-man-restart of debugger, some of debugger state
8330 and command-line options may be lost.
8331 Currently the following settings are preserved:
8332 history, breakpoints and actions, debugger B<O>ptions
8333 and the following command-line options: I<-w>, I<-I>, I<-e>.
8335 B<O> [I<opt>] ... Set boolean option to true
8336 B<O> [I<opt>B<?>] Query options
8337 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
8338 Set options. Use quotes if spaces in value.
8339 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
8340 I<pager> program for output of \"|cmd\";
8341 I<tkRunning> run Tk while prompting (with ReadLine);
8342 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
8343 I<inhibit_exit> Allows stepping off the end of the script.
8344 I<ImmediateStop> Debugger should stop as early as possible.
8345 I<RemotePort> Remote hostname:port for remote debugging
8346 The following options affect what happens with B<V>, B<X>, and B<x> commands:
8347 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
8348 I<compactDump>, I<veryCompact> change style of array and hash dump;
8349 I<globPrint> whether to print contents of globs;
8350 I<DumpDBFiles> dump arrays holding debugged files;
8351 I<DumpPackages> dump symbol tables of packages;
8352 I<DumpReused> dump contents of \"reused\" addresses;
8353 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
8354 I<bareStringify> Do not print the overload-stringified value;
8355 Other options include:
8356 I<PrintRet> affects printing of return value after B<r> command,
8357 I<frame> affects printing messages on subroutine entry/exit.
8358 I<AutoTrace> affects printing messages on possible breaking points.
8359 I<maxTraceLen> gives max length of evals/args listed in stack trace.
8360 I<ornaments> affects screen appearance of the command line.
8361 I<CreateTTY> bits control attempts to create a new TTY on events:
8362 1: on fork() 2: debugger is started inside debugger
8364 During startup options are initialized from \$ENV{PERLDB_OPTS}.
8365 You can put additional initialization options I<TTY>, I<noTTY>,
8366 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
8367 B<R> after you set them).
8369 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
8370 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
8371 B<h h> Summary of debugger commands.
8372 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
8373 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
8374 Set B<\$DB::doccmd> to change viewer.
8376 Type '|h' for a paged display if this was too hard to read.
8378 "; # Fix balance of vi % matching: }}}}
8380 # note: tabs in the following section are not-so-helpful
8381 $pre580_summary = <<"END_SUM";
8382 I<List/search source lines:> I<Control script execution:>
8383 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
8384 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
8385 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
8386 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
8387 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
8388 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
8389 I<Debugger controls:> B<L> List break/watch/actions
8390 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
8391 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
8392 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
8393 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
8394 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
8395 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
8396 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
8397 B<q> or B<^D> Quit B<R> Attempt a restart
8398 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
8399 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
8400 B<p> I<expr> Print expression (uses script's current package).
8401 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
8402 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
8403 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
8404 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8405 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
8408 # ')}}; # Fix balance of vi % matching
8410 } ## end sub sethelp
8412 =head2 C<print_help()>
8414 Most of what C<print_help> does is just text formatting. It finds the
8415 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
8416 terminal control characters to simulate them (courtesy of
8417 C<Term::ReadLine::TermCap>).
8422 my $help_str = shift;
8424 # Restore proper alignment destroyed by eeevil I<> and B<>
8425 # ornaments: A pox on both their houses!
8427 # A help command will have everything up to and including
8428 # the first tab sequence padded into a field 16 (or if indented 20)
8429 # wide. If it's wider than that, an extra space will be added.
8431 ^ # only matters at start of line
8432 ( \040{4} | \t )* # some subcommands are indented
8433 ( < ? # so <CR> works
8434 [BI] < [^\t\n] + ) # find an eeevil ornament
8435 ( \t+ ) # original separation, discarded
8436 ( .* ) # this will now start (no earlier) than
8439 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
8440 my $clean = $command;
8441 $clean =~ s/[BI]<([^>]*)>/$1/g;
8443 # replace with this whole string:
8444 ($leadwhite ? " " x 4 : "")
8446 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
8451 $help_str =~ s{ # handle bold ornaments
8452 B < ( [^>] + | > ) >
8454 $Term::ReadLine::TermCap::rl_term_set[2]
8456 . $Term::ReadLine::TermCap::rl_term_set[3]
8459 $help_str =~ s{ # handle italic ornaments
8460 I < ( [^>] + | > ) >
8462 $Term::ReadLine::TermCap::rl_term_set[0]
8464 . $Term::ReadLine::TermCap::rl_term_set[1]
8468 print {$OUT} $help_str;
8471 } ## end sub print_help
8475 This routine does a lot of gyrations to be sure that the pager is C<less>.
8476 It checks for C<less> masquerading as C<more> and records the result in
8477 C<$fixed_less> so we don't have to go through doing the stats again.
8481 use vars qw($fixed_less);
8484 if ($pager =~ /\bless\b/)
8488 elsif ($pager =~ /\bmore\b/)
8490 # Nope, set to more. See what's out there.
8491 my @st_more = stat('/usr/bin/more');
8492 my @st_less = stat('/usr/bin/less');
8494 # is it really less, pretending to be more?
8498 && $st_more[0] == $st_less[0]
8499 && $st_more[1] == $st_less[1]
8509 # We already know if this is set.
8510 return if $fixed_less;
8512 # changes environment!
8513 # 'r' added so we don't do (slow) stats again.
8514 $fixed_less = 1 if _calc_is_less();
8517 } ## end sub fix_less
8519 =head1 DIE AND WARN MANAGEMENT
8523 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
8524 to debug a debugger problem.
8526 It does its best to report the error that occurred, and then forces the
8527 program, debugger, and everything to die.
8533 # No entry/exit messages.
8536 # No return value prints.
8539 # set the abort signal handling to the default (just terminate).
8540 $SIG{'ABRT'} = 'DEFAULT';
8542 # If we enter the signal handler recursively, kill myself with an
8543 # abort signal (so we just terminate).
8544 kill 'ABRT', $$ if $panic++;
8546 # If we can show detailed info, do so.
8547 if ( defined &Carp::longmess ) {
8549 # Don't recursively enter the warn handler, since we're carping.
8550 local $SIG{__WARN__} = '';
8552 # Skip two levels before reporting traceback: we're skipping
8553 # mydie and confess.
8554 local $Carp::CarpLevel = 2; # mydie + confess
8556 # Tell us all about it.
8557 _db_warn( Carp::longmess("Signal @_") );
8560 # No Carp. Tell us about the signal as best we can.
8563 print $DB::OUT "Got signal @_\n";
8568 } ## end sub diesignal
8572 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
8573 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
8579 # No entry/exit trace.
8582 # No return value printing.
8585 # Turn off warn and die handling to prevent recursive entries to this
8587 local $SIG{__WARN__} = '';
8588 local $SIG{__DIE__} = '';
8590 # Load Carp if we can. If $^S is false (current thing being compiled isn't
8591 # done yet), we may not be able to do a require.
8592 eval { require Carp }
8593 if defined $^S; # If error/warning during compilation,
8594 # require may be broken.
8596 # Use the core warn() unless Carp loaded OK.
8598 "\nCannot print stack trace, load with -MCarp option to see stack" ),
8600 unless defined &Carp::longmess;
8602 # Save the current values of $single and $trace, and then turn them off.
8603 my ( $mysingle, $mytrace ) = ( $single, $trace );
8607 # We can call Carp::longmess without its being "debugged" (which we
8608 # don't want - we just want to use it!). Capture this for later.
8609 my $mess = Carp::longmess(@_);
8611 # Restore $single and $trace to their original values.
8612 ( $single, $trace ) = ( $mysingle, $mytrace );
8614 # Use the debugger's own special way of printing warnings to print
8615 # the stack trace message.
8621 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
8622 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
8623 single stepping and tracing during the call to C<Carp::longmess> to avoid
8624 debugging it - we just want to use it.
8626 If C<dieLevel> is zero, we let the program being debugged handle the
8627 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
8628 the debugger takes over all exception handling, printing a backtrace and
8629 displaying the exception via its C<dbwarn()> routine.
8636 local $SIG{__DIE__} = '';
8637 local $SIG{__WARN__} = '';
8638 if ( $dieLevel > 2 ) {
8639 local $SIG{__WARN__} = \&dbwarn;
8640 _db_warn(@_); # Yell no matter what
8643 if ( $dieLevel < 2 ) {
8644 die @_ if $^S; # in eval propagate
8647 # The code used to check $^S to see if compilation of the current thing
8648 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
8649 eval { require Carp };
8652 "\nCannot print stack trace, load with -MCarp option to see stack" )
8653 unless defined &Carp::longmess;
8655 # We do not want to debug this chunk (automatic disabling works
8656 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
8657 # get the stack trace from Carp::longmess (if possible), restore $signal
8658 # and $trace, and then die with the stack trace.
8659 my ( $mysingle, $mytrace ) = ( $single, $trace );
8665 package Carp; # Do not include us in the list
8666 eval { $mess = Carp::longmess(@_); };
8668 ( $single, $trace ) = ( $mysingle, $mytrace );
8672 =head2 C<warnlevel()>
8674 Set the C<$DB::warnLevel> variable that stores the value of the
8675 C<warnLevel> option. Calling C<warnLevel()> with a positive value
8676 results in the debugger taking over all warning handlers. Setting
8677 C<warnLevel> to zero leaves any warning handlers set up by the program
8678 being debugged in place.
8684 my $prevwarn = $SIG{__WARN__} unless $warnLevel;
8687 $SIG{__WARN__} = \&DB::dbwarn;
8690 $SIG{__WARN__} = $prevwarn;
8692 undef $SIG{__WARN__};
8696 } ## end sub warnLevel
8700 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
8701 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
8702 zero lets you use your own C<die()> handler.
8709 my $prevdie = $SIG{__DIE__} unless $dieLevel;
8713 # Always set it to dbdie() for non-zero values.
8714 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
8716 # No longer exists, so don't try to use it.
8717 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
8719 # If we've finished initialization, mention that stack dumps
8720 # are enabled, If dieLevel is 1, we won't stack dump if we die
8722 print $OUT "Stack dump during die enabled",
8723 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
8726 # XXX This is probably obsolete, given that diehard() is gone.
8727 print $OUT "Dump printed too.\n" if $dieLevel > 2;
8728 } ## end if ($dieLevel)
8730 # Put the old one back if there was one.
8732 $SIG{__DIE__} = $prevdie;
8733 print $OUT "Default die handler restored.\n";
8735 undef $SIG{__DIE__};
8736 print $OUT "Die handler removed.\n";
8740 } ## end sub dieLevel
8742 =head2 C<signalLevel>
8744 Number three in a series: set C<signalLevel> to zero to keep your own
8745 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
8746 takes over and handles them with C<DB::diesignal()>.
8752 my $prevsegv = $SIG{SEGV} unless $signalLevel;
8753 my $prevbus = $SIG{BUS} unless $signalLevel;
8754 $signalLevel = shift;
8756 $SIG{SEGV} = \&DB::diesignal;
8757 $SIG{BUS} = \&DB::diesignal;
8760 $SIG{SEGV} = $prevsegv;
8761 $SIG{BUS} = $prevbus;
8765 } ## end sub signalLevel
8767 =head1 SUBROUTINE DECODING SUPPORT
8769 These subroutines are used during the C<x> and C<X> commands to try to
8770 produce as much information as possible about a code reference. They use
8771 L<Devel::Peek> to try to find the glob in which this code reference lives
8772 (if it does) - this allows us to actually code references which correspond
8773 to named subroutines (including those aliased via glob assignment).
8775 =head2 C<CvGV_name()>
8777 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
8778 via that routine. If this fails, return the reference again (when the
8779 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
8785 my $name = CvGV_name_or_bust($in);
8786 defined $name ? $name : $in;
8789 =head2 C<CvGV_name_or_bust> I<coderef>
8791 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
8792 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
8793 find a glob for this ref.
8795 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
8799 use vars qw($skipCvGV);
8801 sub CvGV_name_or_bust {
8803 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
8804 return unless ref $in;
8805 $in = \&$in; # Hard reference...
8806 eval { require Devel::Peek; 1 } or return;
8807 my $gv = Devel::Peek::CvGV($in) or return;
8808 *$gv{PACKAGE} . '::' . *$gv{NAME};
8809 } ## end sub CvGV_name_or_bust
8813 A utility routine used in various places; finds the file where a subroutine
8814 was defined, and returns that filename and a line-number range.
8816 Tries to use C<@sub> first; if it can't find it there, it tries building a
8817 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
8818 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
8819 this way, it brute-force searches C<%sub>, checking for identical references.
8823 sub _find_sub_helper {
8826 return unless defined &$subr;
8827 my $name = CvGV_name_or_bust($subr);
8829 $data = $sub{$name} if defined $name;
8830 return $data if defined $data;
8833 $subr = \&$subr; # Hard reference
8836 $s = $_, last if $subr eq \&$_;
8851 return ( $sub{$subr} || _find_sub_helper($subr) );
8852 } ## end sub find_sub
8856 A subroutine that uses the utility function C<methods_via> to find all the
8857 methods in the class corresponding to the current reference and in
8866 # Figure out the class - either this is the class or it's a reference
8867 # to something blessed into that class.
8869 $class = ref $class if ref $class;
8873 # Show the methods that this class has.
8874 methods_via( $class, '', 1 );
8876 # Show the methods that UNIVERSAL has.
8877 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
8878 } ## end sub methods
8880 =head2 C<methods_via($class, $prefix, $crawl_upward)>
8882 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
8883 all the parent class methods. C<$class> is the name of the next class to
8884 try; C<$prefix> is the message prefix, which gets built up as we go up the
8885 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
8886 higher in the C<@ISA> tree, 0 if we should stop.
8892 # If we've processed this class already, just quit.
8894 return if $seen{$class}++;
8896 # This is a package that is contributing the methods we're about to print.
8898 my $prepend = $prefix ? "via $prefix: " : '';
8901 # Extract from all the symbols in this class.
8902 my $class_ref = do { no strict "refs"; \%{$class . '::'} };
8903 while (my ($name, $glob) = each %$class_ref) {
8904 # references directly in the symbol table are Proxy Constant
8905 # Subroutines, and are by their very nature defined
8906 # Otherwise, check if the thing is a typeglob, and if it is, it decays
8907 # to a subroutine reference, which can be tested by defined.
8908 # $glob might also be the value -1 (from sub foo;)
8909 # or (say) '$$' (from sub foo ($$);)
8910 # \$glob will be SCALAR in both cases.
8911 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob))
8912 && !$seen{$name}++) {
8913 push @to_print, "$prepend$name\n";
8920 print $DB::OUT $_ foreach sort @to_print;
8923 # If the $crawl_upward argument is false, just quit here.
8924 return unless shift;
8926 # $crawl_upward true: keep going up the tree.
8927 # Find all the classes this one is a subclass of.
8928 my $class_ISA_ref = do { no strict "refs"; \@{"${class}::ISA"} };
8929 for my $name ( @$class_ISA_ref ) {
8931 # Set up the new prefix.
8932 $prepend = $prefix ? $prefix . " -> $name" : $name;
8934 # Crawl up the tree and keep trying to crawl up.
8935 methods_via( $name, $prepend, 1 );
8937 } ## end sub methods_via
8939 =head2 C<setman> - figure out which command to use to show documentation
8941 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8946 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|NetWare)\z/s
8947 ? "man" # O Happy Day!
8948 : "perldoc"; # Alas, poor unfortunates
8951 =head2 C<runman> - run the appropriate command to show documentation
8953 Accepts a man page name; runs the appropriate command to display it (set up
8954 during debugger initialization). Uses C<_db_system()> to avoid mucking up the
8955 program's STDIN and STDOUT.
8962 _db_system("$doccmd $doccmd");
8966 # this way user can override, like with $doccmd="man -Mwhatever"
8967 # or even just "man " to disable the path check.
8968 if ( $doccmd ne 'man' ) {
8969 _db_system("$doccmd $page");
8973 $page = 'perl' if lc($page) eq 'help';
8976 my $man1dir = $Config::Config{man1direxp};
8977 my $man3dir = $Config::Config{man3direxp};
8978 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
8980 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
8981 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
8982 chop $manpath if $manpath;
8984 # harmless if missing, I figure
8985 local $ENV{MANPATH} = $manpath if $manpath;
8986 my $nopathopt = $^O =~ /dunno what goes here/;
8991 # I just *know* there are men without -M
8992 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
8997 unless ( $page =~ /^perl\w/ ) {
8998 # Previously the debugger contained a list which it slurped in,
8999 # listing the known "perl" manpages. However, it was out of date,
9000 # with errors both of omission and inclusion. This approach is
9001 # considerably less complex. The failure mode on a butchered
9002 # install is simply that the user has to run man or perldoc
9003 # "manually" with the full manpage name.
9005 # There is a list of $^O values in installperl to determine whether
9006 # the directory is 'pods' or 'pod'. However, we can avoid tight
9007 # coupling to that by simply checking the "non-standard" 'pods'
9009 my $pods = "$Config::Config{privlibexp}/pods";
9010 $pods = "$Config::Config{privlibexp}/pod"
9012 if (-f "$pods/perl$page.pod") {
9013 CORE::system( $doccmd,
9014 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
9018 } ## end if (CORE::system($doccmd...
9021 #use Carp; # This did break, left for debugging
9023 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
9025 Because of the way the debugger interface to the Perl core is designed, any
9026 debugger package globals that C<DB::sub()> requires have to be defined before
9027 any subroutines can be called. These are defined in the second C<BEGIN> block.
9029 This block sets things up so that (basically) the world is sane
9030 before the debugger starts executing. We set up various variables that the
9031 debugger has to have set up before the Perl core starts running:
9037 The debugger's own filehandles (copies of STD and STDOUT for now).
9041 Characters for shell escapes, the recall command, and the history command.
9045 The maximum recursion depth.
9049 The size of a C<w> command's window.
9053 The before-this-line context to be printed in a C<v> (view a window around this line) command.
9057 The fact that we're not in a sub at all right now.
9061 The default SIGINT handler for the debugger.
9065 The appropriate value of the flag in C<$^D> that says the debugger is running
9069 The current debugger recursion level
9073 The list of postponed items and the C<$single> stack (XXX define this)
9077 That we want no return values and no subroutine entry/exit trace.
9083 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
9085 use vars qw($db_stop);
9087 BEGIN { # This does not compile, alas. (XXX eh?)
9088 $IN = \*STDIN; # For bugs before DB::OUT has been opened
9089 $OUT = \*STDERR; # For errors before DB::OUT has been opened
9091 # Define characters used by command parsing.
9092 $sh = '!'; # Shell escape (does not work)
9093 $rc = ','; # Recall command (does not work)
9094 @hist = ('?'); # Show history (does not work)
9095 @truehist = (); # Can be saved for replay (per session)
9097 # This defines the point at which you get the 'deep recursion'
9098 # warning. It MUST be defined or the debugger will not load.
9101 # Number of lines around the current one that are shown in the
9105 # How much before-the-current-line context the 'v' command should
9106 # use in calculating the start of the window it will display.
9109 # We're not in any sub yet, but we need this to be a defined value.
9112 # Set up the debugger's interrupt handler. It simply sets a flag
9113 # ($signal) that DB::DB() will check before each command is executed.
9114 $SIG{INT} = \&DB::catch;
9116 # The following lines supposedly, if uncommented, allow the debugger to
9117 # debug itself. Perhaps we can try that someday.
9118 # This may be enabled to debug debugger:
9119 #$warnLevel = 1 unless defined $warnLevel;
9120 #$dieLevel = 1 unless defined $dieLevel;
9121 #$signalLevel = 1 unless defined $signalLevel;
9123 # This is the flag that says "a debugger is running, please call
9124 # DB::DB and DB::sub". We will turn it on forcibly before we try to
9125 # execute anything in the user's context, because we always want to
9127 $db_stop = 0; # Compiler warning ...
9128 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
9130 # This variable records how many levels we're nested in debugging. Used
9131 # Used in the debugger prompt, and in determining whether it's all over or
9133 $level = 0; # Level of recursive debugging
9135 # "Triggers bug (?) in perl if we postpone this until runtime."
9136 # XXX No details on this yet, or whether we should fix the bug instead
9137 # of work around it. Stay tuned.
9140 # Used to track the current stack depth using the auto-stacked-variable
9142 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
9144 # Don't print return values on exiting a subroutine.
9147 # No extry/exit tracing.
9152 BEGIN { $^W = $ini_warn; } # Switch warnings back
9154 =head1 READLINE SUPPORT - COMPLETION FUNCTION
9158 C<readline> support - adds command completion to basic C<readline>.
9160 Returns a list of possible completions to C<readline> when invoked. C<readline>
9161 will print the longest common substring following the text already entered.
9163 If there is only a single possible completion, C<readline> will use it in full.
9165 This code uses C<map> and C<grep> heavily to create lists of possible
9166 completion. Think LISP in this section.
9172 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
9173 # $text is the text to be completed.
9174 # $line is the incoming line typed by the user.
9175 # $start is the start of the text to be completed in the incoming line.
9176 my ( $text, $line, $start ) = @_;
9178 # Save the initial text.
9179 # The search pattern is current package, ::, extract the next qualifier
9180 # Prefix and pack are set to undef.
9181 my ( $itext, $search, $prefix, $pack ) =
9182 ( $text, "^\Q${package}::\E([^:]+)\$" );
9184 =head3 C<b postpone|compile>
9190 Find all the subroutines that might match in this package
9194 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
9198 Include all the rest of the subs that are known
9202 C<grep> out the ones that match the text we have so far
9206 Return this as the list of possible completions
9212 return sort grep /^\Q$text/, ( keys %sub ),
9213 qw(postpone load compile), # subroutines
9214 ( map { /$search/ ? ($1) : () } keys %sub )
9215 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
9219 Get all the possible files from C<@INC> as it currently stands and
9220 select the ones that match the text so far.
9224 return sort grep /^\Q$text/, values %INC # files
9225 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
9227 =head3 C<V> (list variable) and C<m> (list modules)
9229 There are two entry points for these commands:
9231 =head4 Unqualified package names
9233 Get the top-level packages and grab everything that matches the text
9234 so far. For each match, recursively complete the partial packages to
9235 get all possible matching packages. Return this sorted list.
9239 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9240 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
9241 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
9243 =head4 Qualified package names
9245 Take a partially-qualified package and find all subpackages for it
9246 by getting all the subpackages for the package so far, matching all
9247 the subpackages against the text, and discarding all of them which
9248 start with 'main::'. Return this list.
9252 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9253 grep !/^main::/, grep /^\Q$text/,
9254 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () }
9255 do { no strict 'refs'; keys %{ $prefix . '::' } }
9256 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
9257 and $text =~ /^(.*[^:])::?(\w*)$/
9260 =head3 C<f> - switch files
9262 Here, we want to get a fully-qualified filename for the C<f> command.
9267 =item 1. The original source file itself
9269 =item 2. A file from C<@INC>
9271 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
9277 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
9278 # We might possibly want to switch to an eval (which has a "filename"
9279 # like '(eval 9)'), so we may need to clean up the completion text
9280 # before proceeding.
9281 $prefix = length($1) - length($text);
9286 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
9287 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
9288 out of C<%main::>, add the initial source file, and extract the ones that
9289 match the completion text so far.
9294 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
9296 } ## end if ($line =~ /^\|*f\s+(.*)/)
9298 =head3 Subroutine name completion
9300 We look through all of the defined subs (the keys of C<%sub>) and
9301 return both all the possible matches to the subroutine name plus
9302 all the matches qualified to the current package.
9306 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
9307 $text = substr $text, 1;
9309 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
9311 map { /$search/ ? ($1) : () }
9314 } ## end if ((substr $text, 0, ...
9316 =head3 Scalar, array, and hash completion: partially qualified package
9318 Much like the above, except we have to do a little more cleanup:
9322 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
9330 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
9334 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
9340 Figure out the prefix vs. what needs completing.
9344 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
9351 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
9357 map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
9365 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.
9369 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9370 return db_complete( $out[0], $line, $start );
9373 # Return the list of possibles.
9376 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
9382 =head3 Symbol completion: current package or package C<main>.
9386 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
9393 If it's C<main>, delete main to just get C<::> leading.
9397 $pack = ( $package eq 'main' ? '' : $package ) . '::';
9403 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
9407 $prefix = substr $text, 0, 1;
9408 $text = substr $text, 1;
9416 We look for the lexical scope above DB::DB and auto-complete lexical variables
9417 if PadWalker could be loaded.
9421 if (not $text =~ /::/ and eval { require PadWalker } ) {
9424 my @info = caller($level);
9428 last if $info[3] eq 'DB::DB';
9431 my $lexicals = PadWalker::peek_my($level);
9432 push @out, grep /^\Q$prefix$text/, keys %$lexicals;
9440 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
9444 push @out, map "$prefix$_", grep /^\Q$text/,
9445 ( grep /^_?[a-zA-Z]/, do { no strict 'refs'; keys %$pack } ),
9446 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
9450 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
9456 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9457 return db_complete( $out[0], $line, $start );
9460 # Return the list of possibles.
9462 } ## end if ($text =~ /^[\$@%]/)
9466 We use C<option_val()> to look up the current value of the option. If there's
9467 only a single value, we complete the command in such a way that it is a
9468 complete command for setting the option in question. If there are multiple
9469 possible values, we generate a command consisting of the option plus a trailing
9470 question mark, which, if executed, will list the current value of the option.
9474 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
9475 { # Options after space
9476 # We look for the text to be matched in the list of possible options,
9477 # and fetch the current value.
9478 my @out = grep /^\Q$text/, @options;
9479 my $val = option_val( $out[0], undef );
9481 # Set up a 'query option's value' command.
9483 if ( not defined $val or $val =~ /[\n\r]/ ) {
9485 # There's really nothing else we can do.
9488 # We have a value. Create a proper option-setting command.
9489 elsif ( $val =~ /\s/ ) {
9491 # XXX This may be an extraneous variable.
9494 # We'll want to quote the string (because of the embedded
9495 # whtespace), but we want to make sure we don't end up with
9496 # mismatched quote characters. We try several possibilities.
9497 foreach my $l ( split //, qq/\"\'\#\|/ ) {
9499 # If we didn't find this quote character in the value,
9500 # quote it using this quote character.
9501 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
9503 } ## end elsif ($val =~ /\s/)
9505 # Don't need any quotes.
9510 # If there were multiple possible values, return '? ', which
9511 # makes the command into a query command. If there was just one,
9512 # have readline append that.
9513 $rl_attribs->{completer_terminator_character} =
9514 ( @out == 1 ? $out : '? ' );
9516 # Return list of possibilities.
9518 } ## end if ((substr $line, 0, ...
9520 =head3 Filename completion
9522 For entering filenames. We simply call C<readline>'s C<filename_list()>
9523 method with the completion text to get the possible completions.
9527 return $term->filename_list($text); # filenames
9529 } ## end sub db_complete
9531 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
9533 Functions that possibly ought to be somewhere else.
9543 print $OUT "Use 'q' to quit or 'R' to restart. 'h q' for details.\n";
9548 If we have $ini_pids, save it in the environment; else remove it from the
9549 environment. Used by the C<R> (restart) command.
9554 if ( defined($ini_pids) ) {
9555 $ENV{PERLDB_PIDS} = $ini_pids;
9558 delete( $ENV{PERLDB_PIDS} );
9560 } ## end sub clean_ENV
9562 # PERLDBf_... flag names from perl.h
9563 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
9566 %DollarCaretP_flags = (
9567 PERLDBf_SUB => 0x01, # Debug sub enter/exit
9568 PERLDBf_LINE => 0x02, # Keep line #
9569 PERLDBf_NOOPT => 0x04, # Switch off optimizations
9570 PERLDBf_INTER => 0x08, # Preserve more data
9571 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
9572 PERLDBf_SINGLE => 0x20, # Start with single-step on
9573 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
9574 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
9575 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
9576 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
9577 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"}
9578 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO
9580 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger
9581 # doesn't need to set it. It's provided for the benefit of profilers and
9582 # other code analysers.
9584 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
9587 sub parse_DollarCaretP_flags {
9592 foreach my $f ( split /\s*\|\s*/, $flags ) {
9594 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
9597 elsif ( $f =~ /^(\d+)$/ ) {
9600 elsif ( $f =~ /^DEFAULT$/i ) {
9601 $value = $DollarCaretP_flags{PERLDB_ALL};
9604 $f =~ /^(?:PERLDBf_)?(.*)$/i;
9605 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
9606 unless ( defined $value ) {
9608 "Unrecognized \$^P flag '$f'!\n",
9609 "Acceptable flags are: "
9610 . join( ', ', sort keys %DollarCaretP_flags ),
9611 ", and hexadecimal and decimal numbers.\n"
9621 sub expand_DollarCaretP_flags {
9622 my $DollarCaretP = shift;
9625 my $n = ( 1 << $_ );
9626 ( $DollarCaretP & $n )
9627 ? ( $DollarCaretP_flags_r{$n}
9628 || sprintf( '0x%x', $n ) )
9632 return @bits ? join( '|', @bits ) : 0;
9639 Rerun the current session to:
9641 rerun current position
9643 rerun 4 command number 4
9645 rerun -4 current command minus 4 (go back 4 steps)
9647 Whether this always makes sense, in the current context is unknowable, and is
9648 in part left as a useful exercise for the reader. This sub returns the
9649 appropriate arguments to rerun the current session.
9656 pop(@truehist); # strim
9657 unless (defined $truehist[$i]) {
9658 print "Unable to return to non-existent command: $i\n";
9660 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
9661 my @temp = @truehist; # store
9662 push(@DB::typeahead, @truehist); # saved
9663 @truehist = @hist = (); # flush
9664 @args = restart(); # setup
9665 get_list("PERLDB_HIST"); # clean
9666 set_list("PERLDB_HIST", @temp); # reset
9673 Restarting the debugger is a complex operation that occurs in several phases.
9674 First, we try to reconstruct the command line that was used to invoke Perl
9680 # I may not be able to resurrect you, but here goes ...
9682 "Warning: some settings and command-line options may be lost!\n";
9683 my ( @script, @flags, $cl );
9685 # If warn was on before, turn it on again.
9686 push @flags, '-w' if $ini_warn;
9688 # Rebuild the -I flags that were on the initial
9691 push @flags, '-I', $_;
9694 # Turn on taint if it was on before.
9695 push @flags, '-T' if ${^TAINT};
9697 # Arrange for setting the old INC:
9698 # Save the current @init_INC in the environment.
9699 set_list( "PERLDB_INC", @ini_INC );
9701 # If this was a perl one-liner, go to the "file"
9702 # corresponding to the one-liner read all the lines
9703 # out of it (except for the first one, which is going
9704 # to be added back on again when 'perl -d' runs: that's
9705 # the 'require perl5db.pl;' line), and add them back on
9706 # to the command line to be executed.
9708 my $lines = *{$main::{'_<-e'}}{ARRAY};
9709 for ( 1 .. $#$lines ) { # The first line is PERL5DB
9710 chomp( $cl = $lines->[$_] );
9711 push @script, '-e', $cl;
9713 } ## end if ($0 eq '-e')
9715 # Otherwise we just reuse the original name we had
9723 After the command line has been reconstructed, the next step is to save
9724 the debugger's status in environment variables. The C<DB::set_list> routine
9725 is used to save aggregate variables (both hashes and arrays); scalars are
9726 just popped into environment variables directly.
9730 # If the terminal supported history, grab it and
9731 # save that in the environment.
9732 set_list( "PERLDB_HIST",
9733 $term->Features->{getHistory}
9737 # Find all the files that were visited during this
9738 # session (i.e., the debugger had magic hashes
9739 # corresponding to them) and stick them in the environment.
9740 my @had_breakpoints = keys %had_breakpoints;
9741 set_list( "PERLDB_VISITED", @had_breakpoints );
9743 # Save the debugger options we chose.
9744 set_list( "PERLDB_OPT", %option );
9745 # set_list( "PERLDB_OPT", options2remember() );
9747 # Save the break-on-loads.
9748 set_list( "PERLDB_ON_LOAD", %break_on_load );
9752 The most complex part of this is the saving of all of the breakpoints. They
9753 can live in an awful lot of places, and we have to go through all of them,
9754 find the breakpoints, and then save them in the appropriate environment
9755 variable via C<DB::set_list>.
9759 # Go through all the breakpoints and make sure they're
9762 for ( 0 .. $#had_breakpoints ) {
9764 # We were in this file.
9765 my $file = $had_breakpoints[$_];
9767 # Grab that file's magic line hash.
9768 *dbline = $main::{ '_<' . $file };
9770 # Skip out if it doesn't exist, or if the breakpoint
9771 # is in a postponed file (we'll do postponed ones
9773 next unless %dbline or $postponed_file{$file};
9775 # In an eval. This is a little harder, so we'll
9776 # do more processing on that below.
9777 ( push @hard, $file ), next
9778 if $file =~ /^\(\w*eval/;
9780 # XXX I have no idea what this is doing. Yet.
9782 @add = %{ $postponed_file{$file} }
9783 if $postponed_file{$file};
9785 # Save the list of all the breakpoints for this file.
9786 set_list( "PERLDB_FILE_$_", %dbline, @add );
9788 # Serialize the extra data %breakpoints_data hash.
9790 set_list( "PERLDB_FILE_ENABLED_$_",
9791 map { _is_breakpoint_enabled($file, $_) ? 1 : 0 }
9792 sort { $a <=> $b } keys(%dbline)
9794 } ## end for (0 .. $#had_breakpoints)
9796 # The breakpoint was inside an eval. This is a little
9797 # more difficult. XXX and I don't understand it.
9798 foreach my $hard_file (@hard) {
9799 # Get over to the eval in question.
9800 *dbline = $main::{ '_<' . $hard_file };
9801 my $quoted = quotemeta $hard_file;
9803 for my $sub ( keys %sub ) {
9804 if (my ($n1, $n2) = $sub{$sub} =~ /\A$quoted:(\d+)-(\d+)\z/) {
9805 $subs{$sub} = [ $n1, $n2 ];
9810 "No subroutines in $hard_file, ignoring breakpoints.\n";
9813 LINES: foreach my $line ( keys %dbline ) {
9815 # One breakpoint per sub only:
9816 my ( $offset, $found );
9817 SUBS: foreach my $sub ( keys %subs ) {
9819 $subs{$sub}->[1] >= $line # Not after the subroutine
9821 not defined $offset # Not caught
9827 $offset = $line - $subs{$sub}->[0];
9829 $offset = "+$offset";
9832 } ## end if ($subs{$sub}->[1] >=...
9833 } ## end for $sub (keys %subs)
9834 if ( defined $offset ) {
9835 $postponed{$found} =
9836 "break $offset if $dbline{$line}";
9840 ("Breakpoint in ${hard_file}:$line ignored:"
9841 . " after all the subroutines.\n");
9843 } ## end for $line (keys %dbline)
9844 } ## end for (@hard)
9846 # Save the other things that don't need to be
9848 set_list( "PERLDB_POSTPONE", %postponed );
9849 set_list( "PERLDB_PRETYPE", @$pretype );
9850 set_list( "PERLDB_PRE", @$pre );
9851 set_list( "PERLDB_POST", @$post );
9852 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9854 # We are officially restarting.
9855 $ENV{PERLDB_RESTART} = 1;
9857 # We are junking all child debuggers.
9858 delete $ENV{PERLDB_PIDS}; # Restore ini state
9860 # Set this back to the initial pid.
9861 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9865 After all the debugger status has been saved, we take the command we built up
9866 and then return it, so we can C<exec()> it. The debugger will spot the
9867 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9868 from the environment.
9872 # And run Perl again. Add the "-d" flag, all the
9873 # flags we built up, the script (whether a one-liner
9874 # or a file), add on the -emacs flag for a slave editor,
9875 # and then the old arguments.
9877 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9883 =head1 END PROCESSING - THE C<END> BLOCK
9885 Come here at the very end of processing. We want to go into a
9886 loop where we allow the user to enter commands and interact with the
9887 debugger, but we don't want anything else to execute.
9889 First we set the C<$finished> variable, so that some commands that
9890 shouldn't be run after the end of program quit working.
9892 We then figure out whether we're truly done (as in the user entered a C<q>
9893 command, or we finished execution while running nonstop). If we aren't,
9894 we set C<$single> to 1 (causing the debugger to get control again).
9896 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9897 message and returns control to the debugger. Repeat.
9899 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9900 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9901 break, run to completion.).
9906 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9907 $fall_off_end = 1 unless $inhibit_exit;
9909 # Do not stop in at_exit() and destructors on exit:
9910 if ($fall_off_end or $runnonstop) {
9914 DB::fake::at_exit();
9918 =head1 PRE-5.8 COMMANDS
9920 Some of the commands changed function quite a bit in the 5.8 command
9921 realignment, so much so that the old code had to be replaced completely.
9922 Because we wanted to retain the option of being able to go back to the
9923 former command set, we moved the old code off to this section.
9925 There's an awful lot of duplicated code here. We've duplicated the
9926 comments to keep things clear.
9930 Does nothing. Used to I<turn off> commands.
9934 sub cmd_pre580_null {
9939 =head2 Old C<a> command.
9941 This version added actions if you supplied them, and deleted them
9950 # Argument supplied. Add the action.
9951 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9953 # If the line isn't there, use the current line.
9954 my $i = $1 || $line;
9957 # If there is an action ...
9960 # ... but the line isn't breakable, skip it.
9961 if ( $dbline[$i] == 0 ) {
9962 print $OUT "Line $i may not have an action.\n";
9966 # ... and the line is breakable:
9967 # Mark that there's an action in this file.
9968 $had_breakpoints{$filename} |= 2;
9970 # Delete any current action.
9971 $dbline{$i} =~ s/\0[^\0]*//;
9973 # Add the new action, continuing the line as needed.
9974 $dbline{$i} .= "\0" . action($j);
9976 } ## end if (length $j)
9978 # No action supplied.
9981 # Delete the action.
9982 $dbline{$i} =~ s/\0[^\0]*//;
9984 # Mark as having no break or action if nothing's left.
9985 delete $dbline{$i} if $dbline{$i} eq '';
9987 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
9988 } ## end sub cmd_pre580_a
9990 =head2 Old C<b> command
10002 if ( $cmd =~ /^load\b\s*(.*)/ ) {
10008 # b compile|postpone <some sub> [<condition>]
10009 # The interpreter actually traps this one for us; we just put the
10010 # necessary condition in the %postponed hash.
10011 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
10013 # Capture the condition if there is one. Make it true if none.
10014 my $cond = length $3 ? $3 : '1';
10016 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
10017 # if it was 'compile'.
10018 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
10020 # De-Perl4-ify the name - ' separators to ::.
10021 $subname =~ s/\'/::/g;
10023 # Qualify it into the current package unless it's already qualified.
10024 $subname = "${package}::" . $subname
10025 unless $subname =~ /::/;
10027 # Add main if it starts with ::.
10028 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
10030 # Save the break type for this sub.
10031 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
10032 } ## end elsif ($cmd =~ ...
10034 # b <sub name> [<condition>]
10035 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
10037 my $cond = length $2 ? $2 : '1';
10038 cmd_b_sub( $subname, $cond );
10040 # b <line> [<condition>].
10041 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
10042 my $i = $1 || $dbline;
10043 my $cond = length $2 ? $2 : '1';
10044 cmd_b_line( $i, $cond );
10046 } ## end sub cmd_pre580_b
10048 =head2 Old C<D> command.
10050 Delete all breakpoints unconditionally.
10057 if ( $cmd =~ /^\s*$/ ) {
10058 print $OUT "Deleting all breakpoints...\n";
10060 # %had_breakpoints lists every file that had at least one
10061 # breakpoint in it.
10063 for $file ( keys %had_breakpoints ) {
10065 # Switch to the desired file temporarily.
10066 local *dbline = $main::{ '_<' . $file };
10071 # For all lines in this file ...
10072 for my $i (1 .. $max) {
10074 # If there's a breakpoint or action on this line ...
10075 if ( defined $dbline{$i} ) {
10077 # ... remove the breakpoint.
10078 $dbline{$i} =~ s/^[^\0]+//;
10079 if ( $dbline{$i} =~ s/^\0?$// ) {
10081 # Remove the entry altogether if no action is there.
10082 delete $dbline{$i};
10084 } ## end if (defined $dbline{$i...
10085 } ## end for my $i (1 .. $max)
10087 # If, after we turn off the "there were breakpoints in this file"
10088 # bit, the entry in %had_breakpoints for this file is zero,
10089 # we should remove this file from the hash.
10090 if ( not $had_breakpoints{$file} &= ~1 ) {
10091 delete $had_breakpoints{$file};
10093 } ## end for $file (keys %had_breakpoints)
10095 # Kill off all the other breakpoints that are waiting for files that
10096 # haven't been loaded yet.
10098 undef %postponed_file;
10099 undef %break_on_load;
10100 } ## end if ($cmd =~ /^\s*$/)
10101 } ## end sub cmd_pre580_D
10103 =head2 Old C<h> command
10105 Print help. Defaults to printing the long-form help; the 5.8 version
10106 prints the summary by default.
10114 # Print the *right* help, long format.
10115 if ( $cmd =~ /^\s*$/ ) {
10116 print_help($pre580_help);
10119 # 'h h' - explicitly-requested summary.
10120 elsif ( $cmd =~ /^h\s*/ ) {
10121 print_help($pre580_summary);
10124 # Find and print a command's help.
10125 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
10126 my $asked = $1; # for proper errmsg
10127 my $qasked = quotemeta($asked); # for searching
10128 # XXX: finds CR but not <CR>
10132 (?:[IB]<) # Optional markup
10133 $qasked # The command name
10140 ( # The command help:
10142 (?:[IB]<) # Optional markup
10143 $qasked # The command name
10144 ([\s\S]*?) # Lines starting with tabs
10148 ) # Line not starting with space
10149 # (Next command's help)
10153 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
10157 print_help("B<$asked> is not a debugger command.\n");
10159 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
10160 } ## end sub cmd_pre580_h
10162 =head2 Old C<W> command
10164 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
10172 # Delete all watch expressions.
10173 if ( $cmd =~ /^$/ ) {
10175 # No watching is going on.
10178 # Kill all the watch expressions and values.
10179 @to_watch = @old_watch = ();
10182 # Add a watch expression.
10183 elsif ( $cmd =~ /^(.*)/s ) {
10185 # add it to the list to be watched.
10186 push @to_watch, $1;
10188 # Get the current value of the expression.
10189 # Doesn't handle expressions returning list values!
10191 # The &-call is here to ascertain the mutability of @_.
10192 my ($val) = &DB::eval;
10193 $val = ( defined $val ) ? "'$val'" : 'undef';
10196 push @old_watch, $val;
10198 # We're watching stuff.
10201 } ## end elsif ($cmd =~ /^(.*)/s)
10202 } ## end sub cmd_pre580_W
10204 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
10206 The debugger used to have a bunch of nearly-identical code to handle
10207 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
10208 C<cmd_prepost> unify all this into one set of code to handle the
10209 appropriate actions.
10211 =head2 C<cmd_pre590_prepost>
10213 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
10214 do something destructive. In pre 5.8 debuggers, the default action was to
10215 delete all the actions.
10219 sub cmd_pre590_prepost {
10221 my $line = shift || '*';
10222 my $dbline = shift;
10224 return cmd_prepost( $cmd, $line, $dbline );
10225 } ## end sub cmd_pre590_prepost
10227 =head2 C<cmd_prepost>
10229 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
10230 Since the lists of actions are all held in arrays that are pointed to by
10231 references anyway, all we have to do is pick the right array reference and
10232 then use generic code to all, delete, or list actions.
10239 # No action supplied defaults to 'list'.
10240 my $line = shift || '?';
10242 # Figure out what to put in the prompt.
10245 # Make sure we have some array or another to address later.
10246 # This means that if for some reason the tests fail, we won't be
10247 # trying to stash actions or delete them from the wrong place.
10250 # < - Perl code to run before prompt.
10251 if ( $cmd =~ /^\</o ) {
10252 $which = 'pre-perl';
10256 # > - Perl code to run after prompt.
10257 elsif ( $cmd =~ /^\>/o ) {
10258 $which = 'post-perl';
10262 # { - first check for properly-balanced braces.
10263 elsif ( $cmd =~ /^\{/o ) {
10264 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
10266 "$cmd is now a debugger command\nuse ';$cmd' if you mean Perl code\n";
10269 # Properly balanced. Pre-prompt debugger actions.
10271 $which = 'pre-debugger';
10274 } ## end elsif ( $cmd =~ /^\{/o )
10276 # Did we find something that makes sense?
10278 print $OUT "Confused by command: $cmd\n";
10285 if ( $line =~ /^\s*\?\s*$/o ) {
10288 # Nothing there. Complain.
10289 print $OUT "No $which actions.\n";
10293 # List the actions in the selected list.
10294 print $OUT "$which commands:\n";
10295 foreach my $action (@$aref) {
10296 print $OUT "\t$cmd -- $action\n";
10299 } ## end if ( $line =~ /^\s*\?\s*$/o)
10301 # Might be a delete.
10303 if ( length($cmd) == 1 ) {
10304 if ( $line =~ /^\s*\*\s*$/o ) {
10306 # It's a delete. Get rid of the old actions in the
10309 print $OUT "All $cmd actions cleared.\n";
10313 # Replace all the actions. (This is a <, >, or {).
10314 @$aref = action($line);
10316 } ## end if ( length($cmd) == 1)
10317 elsif ( length($cmd) == 2 ) {
10319 # Add the action to the line. (This is a <<, >>, or {{).
10320 push @$aref, action($line);
10324 # <<<, >>>>, {{{{{{ ... something not a command.
10326 "Confused by strange length of $which command($cmd)...\n";
10328 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
10330 } ## end sub cmd_prepost
10334 Contains the C<at_exit> routine that the debugger uses to issue the
10335 C<Debugged program terminated ...> message after the program completes. See
10336 the C<END> block documentation for more details.
10343 "Debugged program terminated. Use 'q' to quit or 'R' to restart.";
10346 package DB; # Do not trace this 1; below!