4 perl5db.pl - the perl debugger
8 perl -d your_Perl_script
12 C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when
13 you invoke a script with C<perl -d>. This documentation tries to outline the
14 structure and services provided by C<perl5db.pl>, and to describe how you
19 The debugger can look pretty forbidding to many Perl programmers. There are
20 a number of reasons for this, many stemming out of the debugger's history.
22 When the debugger was first written, Perl didn't have a lot of its nicer
23 features - no references, no lexical variables, no closures, no object-oriented
24 programming. So a lot of the things one would normally have done using such
25 features was done using global variables, globs and the C<local()> operator
28 Some of these have survived into the current debugger; a few of the more
29 interesting and still-useful idioms are noted in this section, along with notes
30 on the comments themselves.
32 =head2 Why not use more lexicals?
34 Experienced Perl programmers will note that the debugger code tends to use
35 mostly package globals rather than lexically-scoped variables. This is done
36 to allow a significant amount of control of the debugger from outside the
39 Unfortunately, though the variables are accessible, they're not well
40 documented, so it's generally been a decision that hasn't made a lot of
41 difference to most users. Where appropriate, comments have been added to
42 make variables more accessible and usable, with the understanding that these
43 I<are> debugger internals, and are therefore subject to change. Future
44 development should probably attempt to replace the globals with a well-defined
45 API, but for now, the variables are what we've got.
47 =head2 Automated variable stacking via C<local()>
49 As you may recall from reading C<perlfunc>, the C<local()> operator makes a
50 temporary copy of a variable in the current scope. When the scope ends, the
51 old copy is restored. This is often used in the debugger to handle the
52 automatic stacking of variables during recursive calls:
57 # Do some stuff, then ...
61 What happens is that on entry to the subroutine, C<$some_global> is localized,
62 then altered. When the subroutine returns, Perl automatically undoes the
63 localization, restoring the previous value. Voila, automatic stack management.
65 The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>,
66 which lets the debugger get control inside of C<eval>'ed code. The debugger
67 localizes a saved copy of C<$@> inside the subroutine, which allows it to
68 keep C<$@> safe until it C<DB::eval> returns, at which point the previous
69 value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep
70 track of C<$@> inside C<eval>s which C<eval> other C<eval's>.
72 In any case, watch for this pattern. It occurs fairly often.
76 This is used to cleverly reverse the sense of a logical test depending on
77 the value of an auxiliary variable. For instance, the debugger's C<S>
78 (search for subroutines by pattern) allows you to negate the pattern
81 # Find all non-'foo' subs:
84 Boolean algebra states that the truth table for XOR looks like this:
90 (! not present and no match) --> false, don't print
94 (! not present and matches) --> true, print
98 (! present and no match) --> true, print
102 (! present and matches) --> false, don't print
106 As you can see, the first pair applies when C<!> isn't supplied, and
107 the second pair applies when it is. The XOR simply allows us to
108 compact a more complicated if-then-elseif-else into a more elegant
109 (but perhaps overly clever) single test. After all, it needed this
112 =head2 FLAGS, FLAGS, FLAGS
114 There is a certain C programming legacy in the debugger. Some variables,
115 such as C<$single>, C<$trace>, and C<$frame>, have I<magical> values composed
116 of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces
117 of state to be stored independently in a single scalar.
123 is checking to see if the appropriate bit is on. Since each bit can be
124 "addressed" independently in this way, C<$scalar> is acting sort of like
125 an array of bits. Obviously, since the contents of C<$scalar> are just a
126 bit-pattern, we can save and restore it easily (it will just look like
129 The problem, is of course, that this tends to leave magic numbers scattered
130 all over your program whenever a bit is set, cleared, or checked. So why do
137 First, doing an arithmetical or bitwise operation on a scalar is
138 just about the fastest thing you can do in Perl: C<use constant> actually
139 creates a subroutine call, and array and hash lookups are much slower. Is
140 this over-optimization at the expense of readability? Possibly, but the
141 debugger accesses these variables a I<lot>. Any rewrite of the code will
142 probably have to benchmark alternate implementations and see which is the
143 best balance of readability and speed, and then document how it actually
148 Second, it's very easy to serialize a scalar number. This is done in
149 the restart code; the debugger state variables are saved in C<%ENV> and then
150 restored when the debugger is restarted. Having them be just numbers makes
155 Third, some of these variables are being shared with the Perl core
156 smack in the middle of the interpreter's execution loop. It's much faster for
157 a C program (like the interpreter) to check a bit in a scalar than to access
158 several different variables (or a Perl array).
162 =head2 What are those C<XXX> comments for?
164 Any comment containing C<XXX> means that the comment is either somewhat
165 speculative - it's not exactly clear what a given variable or chunk of
166 code is doing, or that it is incomplete - the basics may be clear, but the
167 subtleties are not completely documented.
169 Send in a patch if you can clear up, fill out, or clarify an C<XXX>.
171 =head1 DATA STRUCTURES MAINTAINED BY CORE
173 There are a number of special data structures provided to the debugger by
174 the Perl interpreter.
176 The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline>
177 via glob assignment) contains the text from C<$filename>, with each
178 element corresponding to a single line of C<$filename>. Additionally,
179 breakable lines will be dualvars with the numeric component being the
180 memory address of a COP node. Non-breakable lines are dualvar to 0.
182 The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
183 assignment) contains breakpoints and actions. The keys are line numbers;
184 you can set individual values, but not the whole hash. The Perl interpreter
185 uses this hash to determine where breakpoints have been set. Any true value is
186 considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>.
187 Values are magical in numeric context: 1 if the line is breakable, 0 if not.
189 The scalar C<${"_<$filename"}> simply contains the string C<$filename>.
190 This is also the case for evaluated strings that contain subroutines, or
191 which are currently being executed. The $filename for C<eval>ed strings looks
194 =head1 DEBUGGER STARTUP
196 When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
197 non-interactive sessions, C<.perldb> for interactive ones) that can set a number
198 of options. In addition, this file may define a subroutine C<&afterinit>
199 that will be executed (in the debugger's context) after the debugger has
202 Next, it checks the C<PERLDB_OPTS> environment variable and treats its
203 contents as the argument of a C<o> command in the debugger.
205 =head2 STARTUP-ONLY OPTIONS
207 The following options can only be specified at startup.
208 To set them in your rcfile, add a call to
209 C<&parse_options("optionName=new_value")>.
215 the TTY to use for debugging i/o.
219 if set, goes in NonStop mode. On interrupt, if TTY is not set,
220 uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using
221 Term::Rendezvous. Current variant is to have the name of TTY in this
226 if false, a dummy ReadLine is used, so you can debug
227 ReadLine applications.
231 if true, no i/o is performed until interrupt.
235 file or pipe to print line number info to. If it is a
236 pipe, a short "emacs like" message is used.
240 host:port to connect to on remote host for remote debugging.
244 file to store session history to. There is no default and so no
245 history file is written unless this variable is explicitly set.
249 number of commands to store to the file specified in C<HistFile>.
256 &parse_options("NonStop=1 LineInfo=db.out");
257 sub afterinit { $trace = 1; }
259 The script will run without human intervention, putting trace
260 information into C<db.out>. (If you interrupt it, you had better
261 reset C<LineInfo> to something I<interactive>!)
263 =head1 INTERNALS DESCRIPTION
265 =head2 DEBUGGER INTERFACE VARIABLES
267 Perl supplies the values for C<%sub>. It effectively inserts
268 a C<&DB::DB();> in front of each place that can have a
269 breakpoint. At each subroutine call, it calls C<&DB::sub> with
270 C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
271 {require 'perl5db.pl'}> before the first line.
273 After each C<require>d file is compiled, but before it is executed, a
274 call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
275 is the expanded name of the C<require>d file (as found via C<%INC>).
277 =head3 IMPORTANT INTERNAL VARIABLES
281 Used to control when the debugger will attempt to acquire another TTY to be
286 =item * 1 - on C<fork()>
288 =item * 2 - debugger is started inside debugger
290 =item * 4 - on startup
296 The value -2 indicates that no return value should be printed.
297 Any other positive value causes C<DB::sub> to print return values.
301 The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
302 contents of C<@_> when C<DB::eval> is called.
306 Determines what messages (if any) will get printed when a subroutine (or eval)
307 is entered or exited.
311 =item * 0 - No enter/exit messages
313 =item * 1 - Print I<entering> messages on subroutine entry
315 =item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
317 =item * 4 - Extended messages: C<< <in|out> I<context>=I<fully-qualified sub name> from I<file>:I<line> >>. If no other flag is on, acts like 1+4.
319 =item * 8 - Adds parameter information to messages, and overloaded stringify and tied FETCH is enabled on the printed arguments. Ignored if C<4> is not on.
321 =item * 16 - Adds C<I<context> return from I<subname>: I<value>> messages on subroutine/eval exit. Ignored if C<4> is not on.
325 To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
326 The debugger internally juggles the value of C<$frame> during execution to
327 protect external modules that the debugger uses from getting traced.
331 Tracks current debugger nesting level. Used to figure out how many
332 C<E<lt>E<gt>> pairs to surround the line number with when the debugger
333 outputs a prompt. Also used to help determine if the program has finished
334 during command parsing.
336 =head4 C<$onetimeDump>
338 Controls what (if anything) C<DB::eval()> will print after evaluating an
343 =item * C<undef> - don't print anything
345 =item * C<dump> - use C<dumpvar.pl> to display the value returned
347 =item * C<methods> - print the methods callable on the first item returned
351 =head4 C<$onetimeDumpDepth>
353 Controls how far down C<dumpvar.pl> will go before printing C<...> while
354 dumping a structure. Numeric. If C<undef>, print all levels.
358 Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
359 which is called before every statement, checks this and puts the user into
360 command mode if it finds C<$signal> set to a true value.
364 Controls behavior during single-stepping. Stacked in C<@stack> on entry to
365 each subroutine; popped again at the end of each subroutine.
369 =item * 0 - run continuously.
371 =item * 1 - single-step, go into subs. The C<s> command.
373 =item * 2 - single-step, don't go into subs. The C<n> command.
375 =item * 4 - print current sub depth (turned on to force this when C<too much
382 Controls the output of trace information.
386 =item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
388 =item * 2 - watch expressions are active
390 =item * 4 - user defined a C<watchfunction()> in C<afterinit()>
394 =head4 C<$slave_editor>
396 1 if C<LINEINFO> was directed to a pipe; 0 otherwise.
400 Stack of filehandles that C<DB::readline()> will read commands from.
401 Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
405 Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
406 supplied by the Perl interpreter to the debugger. Contains the source.
410 Previous values of watch expressions. First set when the expression is
411 entered; reset whenever the watch expression changes.
415 Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
416 so that the debugger can substitute safe values while it's running, and
417 restore them when it returns control.
421 Saves the current value of C<$single> on entry to a subroutine.
422 Manipulated by the C<c> command to turn off tracing in all subs above the
427 The 'watch' expressions: to be evaluated before each line is executed.
431 The typeahead buffer, used by C<DB::readline>.
435 Command aliases. Stored as character strings to be substituted for a command
438 =head4 C<%break_on_load>
440 Keys are file names, values are 1 (break when this file is loaded) or undef
441 (don't break when it is loaded).
445 Keys are line numbers, values are C<condition\0action>. If used in numeric
446 context, values are 0 if not breakable, 1 if breakable, no matter what is
447 in the actual hash entry.
449 =head4 C<%had_breakpoints>
451 Keys are file names; values are bitfields:
455 =item * 1 - file has a breakpoint in it.
457 =item * 2 - file has an action in it.
461 A zero or undefined value means this file has neither.
465 Stores the debugger options. These are character string values.
469 Saves breakpoints for code that hasn't been compiled yet.
470 Keys are subroutine names, values are:
474 =item * C<compile> - break when this sub is compiled
476 =item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
480 =head4 C<%postponed_file>
482 This hash keeps track of breakpoints that need to be set for files that have
483 not yet been compiled. Keys are filenames; values are references to hashes.
484 Each of these hashes is keyed by line number, and its values are breakpoint
485 definitions (C<condition\0action>).
487 =head1 DEBUGGER INITIALIZATION
489 The debugger's initialization actually jumps all over the place inside this
490 package. This is because there are several BEGIN blocks (which of course
491 execute immediately) spread through the code. Why is that?
493 The debugger needs to be able to change some things and set some things up
494 before the debugger code is compiled; most notably, the C<$deep> variable that
495 C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
496 debugger has to turn off warnings while the debugger code is compiled, but then
497 restore them to their original setting before the program being debugged begins
500 The first C<BEGIN> block simply turns off warnings by saving the current
501 setting of C<$^W> and then setting it to zero. The second one initializes
502 the debugger variables that are needed before the debugger begins executing.
503 The third one puts C<$^X> back to its former value.
505 We'll detail the second C<BEGIN> block later; just remember that if you need
506 to initialize something before the debugger starts really executing, that's
519 BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
523 $^V =~ /^v(\d+\.\d+)/;
524 feature->import(":$1");
525 $_initial_cwd = Cwd::getcwd();
528 # Debugger for Perl 5.00x; perl5db.pl patch level:
529 use vars qw($VERSION $header);
531 $VERSION = '1.49_02';
533 $header = "perl5db.pl version $VERSION";
535 =head1 DEBUGGER ROUTINES
539 This function replaces straight C<eval()> inside the debugger; it simplifies
540 the process of evaluating code in the user's context.
542 The code to be evaluated is passed via the package global variable
543 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
545 Before we do the C<eval()>, we preserve the current settings of C<$trace>,
546 C<$single>, C<$^D> and C<$usercontext>. The latter contains the
547 preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
548 user's current package, grabbed when C<DB::DB> got control. This causes the
549 proper context to be used when the eval is actually done. Afterward, we
550 restore C<$trace>, C<$single>, and C<$^D>.
552 Next we need to handle C<$@> without getting confused. We save C<$@> in a
553 local lexical, localize C<$saved[0]> (which is where C<save()> will put
554 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
555 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
556 considered sane by the debugger. If there was an C<eval()> error, we print
557 it on the debugger's output. If C<$onetimedump> is defined, we call
558 C<dumpit> if it's set to 'dump', or C<methods> if it's set to
559 'methods'. Setting it to something else causes the debugger to do the eval
560 but not print the result - handy if you want to do something else with it
561 (the "watch expressions" code does this to get the value of the watch
562 expression but not show it unless it matters).
564 In any case, we then return the list of output from C<eval> to the caller,
565 and unwinding restores the former version of C<$@> in C<@saved> as well
566 (the localization of C<$saved[0]> goes away at the end of this scope).
568 =head3 Parameters and variables influencing execution of DB::eval()
570 C<DB::eval> isn't parameterized in the standard way; this is to keep the
571 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
572 The variables listed below influence C<DB::eval()>'s execution directly.
576 =item C<$evalarg> - the thing to actually be eval'ed
578 =item C<$trace> - Current state of execution tracing
580 =item C<$single> - Current state of single-stepping
582 =item C<$onetimeDump> - what is to be displayed after the evaluation
584 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
588 The following variables are altered by C<DB::eval()> during its execution. They
589 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
593 =item C<@res> - used to capture output from actual C<eval>.
595 =item C<$otrace> - saved value of C<$trace>.
597 =item C<$osingle> - saved value of C<$single>.
599 =item C<$od> - saved value of C<$^D>.
601 =item C<$saved[0]> - saved value of C<$@>.
603 =item $\ - for output of C<$@> if there is an evaluation error.
607 =head3 The problem of lexicals
609 The context of C<DB::eval()> presents us with some problems. Obviously,
610 we want to be 'sandboxed' away from the debugger's internals when we do
611 the eval, but we need some way to control how punctuation variables and
612 debugger globals are used.
614 We can't use local, because the code inside C<DB::eval> can see localized
615 variables; and we can't use C<my> either for the same reason. The code
616 in this routine compromises and uses C<my>.
618 After this routine is over, we don't have user code executing in the debugger's
619 context, so we can use C<my> freely.
623 ############################################## Begin lexical danger zone
625 # 'my' variables used here could leak into (that is, be visible in)
626 # the context that the code being evaluated is executing in. This means that
627 # the code could modify the debugger's variables.
629 # Fiddling with the debugger's context could be Bad. We insulate things as
694 # Used to save @ARGV and extract any debugger-related flags.
697 # Used to prevent multiple entries to diesignal()
698 # (if for instance diesignal() itself dies)
701 # Used to prevent the debugger from running nonstop
705 sub _calc_usercontext {
708 # Cancel strict completely for the evaluated code, so the code
709 # the user evaluates won't be affected by it. (Shlomi Fish)
710 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @DB::saved;'
711 . "package $package;"; # this won't let them modify, alas
716 # 'my' would make it visible from user code
717 # but so does local! --tchrist
718 # Remember: this localizes @DB::res, not @main::res.
722 # Try to keep the user code from messing with us. Save these so that
723 # even if the eval'ed code changes them, we can put them back again.
724 # Needed because the user could refer directly to the debugger's
725 # package globals (and any 'my' variables in this containing scope)
726 # inside the eval(), and we want to try to stay safe.
727 local $otrace = $trace;
728 local $osingle = $single;
731 # Untaint the incoming eval() argument.
732 { ($evalarg) = $evalarg =~ /(.*)/s; }
734 # $usercontext built in DB::DB near the comment
735 # "set up the context for DB::eval ..."
736 # Evaluate and save any results.
737 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
739 # Restore those old values.
745 # Save the current value of $@, and preserve it in the debugger's copy
746 # of the saved precious globals.
749 # Since we're only saving $@, we only have to localize the array element
750 # that it will be stored in.
751 local $saved[0]; # Preserve the old value of $@
754 # Now see whether we need to report an error back to the user.
760 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
761 # are package globals.
762 elsif ($onetimeDump) {
763 if ( $onetimeDump eq 'dump' ) {
764 local $option{dumpDepth} = $onetimedumpDepth
765 if defined $onetimedumpDepth;
766 dumpit( $OUT, \@res );
768 elsif ( $onetimeDump eq 'methods' ) {
771 } ## end elsif ($onetimeDump)
775 ############################################## End lexical danger zone
777 # After this point it is safe to introduce lexicals.
778 # The code being debugged will be executing in its own context, and
779 # can't see the inside of the debugger.
781 # However, one should not overdo it: leave as much control from outside as
782 # possible. If you make something a lexical, it's not going to be addressable
783 # from outside the debugger even if you know its name.
785 # This file is automatically included if you do perl -d.
786 # It's probably not useful to include this yourself.
788 # Before venturing further into these twisty passages, it is
789 # wise to read the perldebguts man page or risk the ire of dragons.
791 # (It should be noted that perldebguts will tell you a lot about
792 # the underlying mechanics of how the debugger interfaces into the
793 # Perl interpreter, but not a lot about the debugger itself. The new
794 # comments in this code try to address this problem.)
796 # Note that no subroutine call is possible until &DB::sub is defined
797 # (for subroutines defined outside of the package DB). In fact the same is
798 # true if $deep is not defined.
800 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
802 # modified Perl debugger, to be run from Emacs in perldb-mode
803 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
804 # Johan Vromans -- upgrade to 4.0 pl 10
805 # Ilya Zakharevich -- patches after 5.001 (and some before ;-)
806 ########################################################################
808 =head1 DEBUGGER INITIALIZATION
810 The debugger starts up in phases.
814 First, it initializes the environment it wants to run in: turning off
815 warnings during its own compilation, defining variables which it will need
816 to avoid warnings later, setting itself up to not exit when the program
817 terminates, and defaulting to printing return values for the C<r> command.
821 # Needed for the statement after exec():
823 # This BEGIN block is simply used to switch off warnings during debugger
824 # compilation. Probably it would be better practice to fix the warnings,
825 # but this is how it's done at the moment.
830 } # Switch compilation warnings off until another BEGIN.
832 local ($^W) = 0; # Switch run-time warnings off during init.
834 =head2 THREADS SUPPORT
836 If we are running under a threaded Perl, we require threads and threads::shared
837 if the environment variable C<PERL5DB_THREADED> is set, to enable proper
838 threaded debugger control. C<-dt> can also be used to set this.
840 Each new thread will be announced and the debugger prompt will always inform
841 you of each new thread created. It will also indicate the thread id in which
842 we are currently running within the prompt like this:
846 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
847 command prompt. The prompt will show: C<[0]> when running under threads, but
848 not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
850 While running under threads, when you set or delete a breakpoint (etc.), this
851 will apply to all threads, not just the currently running one. When you are
852 in a currently executing thread, you will stay there until it completes. With
853 the current implementation it is not currently possible to hop from one thread
856 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
858 Note that threading support was built into the debugger as of Perl version
859 C<5.8.6> and debugger version C<1.2.8>.
864 # ensure we can share our non-threaded variables or no-op
865 if ($ENV{PERL5DB_THREADED}) {
867 require threads::shared;
868 import threads::shared qw(share);
872 print "Threads support enabled\n";
875 *share = sub(\[$@%]) {};
879 # These variables control the execution of 'dumpvar.pl'.
894 # used to control die() reporting in diesignal()
897 use vars qw($CarpLevel);
900 # without threads, $filename is not defined until DB::DB is called
901 share($main::{'_<'.$filename}) if defined $filename;
903 # Command-line + PERLLIB:
904 # Save the contents of @INC before they are modified elsewhere.
907 # This was an attempt to clear out the previous values of various
908 # trapped errors. Apparently it didn't help. XXX More info needed!
909 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
911 # We set these variables to safe values. We don't want to blindly turn
912 # off warnings, because other packages may still want them.
913 $trace = $signal = $single = 0; # Uninitialized warning suppression
914 # (local $^W cannot help - other packages!).
916 # Default to not exiting when program finishes; print the return
917 # value when the 'r' command is used to return from a subroutine.
918 $inhibit_exit = $option{PrintRet} = 1;
920 use vars qw($trace_to_depth);
922 # Default to 1E9 so it won't be limited to a certain recursion depth.
923 $trace_to_depth = 1E9;
925 =head1 OPTION PROCESSING
927 The debugger's options are actually spread out over the debugger itself and
928 C<dumpvar.pl>; some of these are variables to be set, while others are
929 subs to be called with a value. To try to make this a little easier to
930 manage, the debugger uses a few data structures to define what options
931 are legal and how they are to be processed.
933 First, the C<@options> array defines the I<names> of all the options that
939 CommandSet HistFile HistSize
940 hashDepth arrayDepth dumpDepth
941 DumpDBFiles DumpPackages DumpReused
942 compactDump veryCompact quote
943 HighBit undefPrint globPrint
944 PrintRet UsageOnly frame
946 ReadLine NonStop LineInfo
947 maxTraceLen recallCommand ShellBang
948 pager tkRunning ornaments
949 signalLevel warnLevel dieLevel
950 inhibit_exit ImmediateStop bareStringify
951 CreateTTY RemotePort windowSize
955 @RememberOnROptions = qw(DollarCaretP);
959 Second, C<optionVars> lists the variables that each option uses to save its
964 use vars qw(%optionVars);
967 hashDepth => \$dumpvar::hashDepth,
968 arrayDepth => \$dumpvar::arrayDepth,
969 CommandSet => \$CommandSet,
970 DumpDBFiles => \$dumpvar::dumpDBFiles,
971 DumpPackages => \$dumpvar::dumpPackages,
972 DumpReused => \$dumpvar::dumpReused,
973 HighBit => \$dumpvar::quoteHighBit,
974 undefPrint => \$dumpvar::printUndef,
975 globPrint => \$dumpvar::globPrint,
976 UsageOnly => \$dumpvar::usageOnly,
977 CreateTTY => \$CreateTTY,
978 bareStringify => \$dumpvar::bareStringify,
980 AutoTrace => \$trace,
981 inhibit_exit => \$inhibit_exit,
982 maxTraceLen => \$maxtrace,
983 ImmediateStop => \$ImmediateStop,
984 RemotePort => \$remoteport,
985 windowSize => \$window,
986 HistFile => \$histfile,
987 HistSize => \$histsize,
992 Third, C<%optionAction> defines the subroutine to be called to process each
997 use vars qw(%optionAction);
1000 compactDump => \&dumpvar::compactDump,
1001 veryCompact => \&dumpvar::veryCompact,
1002 quote => \&dumpvar::quote,
1005 ReadLine => \&ReadLine,
1006 NonStop => \&NonStop,
1007 LineInfo => \&LineInfo,
1008 recallCommand => \&recallCommand,
1009 ShellBang => \&shellBang,
1011 signalLevel => \&signalLevel,
1012 warnLevel => \&warnLevel,
1013 dieLevel => \&dieLevel,
1014 tkRunning => \&tkRunning,
1015 ornaments => \&ornaments,
1016 RemotePort => \&RemotePort,
1017 DollarCaretP => \&DollarCaretP,
1022 Last, the C<%optionRequire> notes modules that must be C<require>d if an
1027 # Note that this list is not complete: several options not listed here
1028 # actually require that dumpvar.pl be loaded for them to work, but are
1029 # not in the table. A subsequent patch will correct this problem; for
1030 # the moment, we're just recommenting, and we are NOT going to change
1032 use vars qw(%optionRequire);
1035 compactDump => 'dumpvar.pl',
1036 veryCompact => 'dumpvar.pl',
1037 quote => 'dumpvar.pl',
1042 There are a number of initialization-related variables which can be set
1043 by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1044 variable. These are:
1048 =item C<$rl> - readline control XXX needs more explanation
1050 =item C<$warnLevel> - whether or not debugger takes over warning handling
1052 =item C<$dieLevel> - whether or not debugger takes over die handling
1054 =item C<$signalLevel> - whether or not debugger takes over signal handling
1056 =item C<$pre> - preprompt actions (array reference)
1058 =item C<$post> - postprompt actions (array reference)
1062 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1064 =item C<$CommandSet> - which command set to use (defaults to new, documented set)
1070 # These guys may be defined in $ENV{PERL5DB} :
1071 $rl = 1 unless defined $rl;
1072 $warnLevel = 1 unless defined $warnLevel;
1073 $dieLevel = 1 unless defined $dieLevel;
1074 $signalLevel = 1 unless defined $signalLevel;
1075 $pre = [] unless defined $pre;
1076 $post = [] unless defined $post;
1077 $pretype = [] unless defined $pretype;
1078 $CreateTTY = 3 unless defined $CreateTTY;
1079 $CommandSet = '580' unless defined $CommandSet;
1084 share($signalLevel);
1094 The default C<die>, C<warn>, and C<signal> handlers are set up.
1098 warnLevel($warnLevel);
1099 dieLevel($dieLevel);
1100 signalLevel($signalLevel);
1104 The pager to be used is needed next. We try to get it from the
1105 environment first. If it's not defined there, we try to find it in
1106 the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1107 then call the C<pager()> function to save the pager name.
1111 # This routine makes sure $pager is set up so that '|' can use it.
1114 # If PAGER is defined in the environment, use it.
1118 # If not, see if Config.pm defines it.
1119 : eval { require Config }
1120 && defined $Config::Config{pager}
1121 ? $Config::Config{pager}
1123 # If not, fall back to 'more'.
1126 unless defined $pager;
1130 We set up the command to be used to access the man pages, the command
1131 recall character (C<!> unless otherwise defined) and the shell escape
1132 character (C<!> unless otherwise defined). Yes, these do conflict, and
1133 neither works in the debugger at the moment.
1139 # Set up defaults for command recall and shell escape (note:
1140 # these currently don't work in linemode debugging).
1141 recallCommand("!") unless defined $prc;
1142 shellBang("!") unless defined $psh;
1146 We then set up the gigantic string containing the debugger help.
1147 We also set the limit on the number of arguments we'll display during a
1154 # If we didn't get a default for the length of eval/stack trace args,
1156 $maxtrace = 400 unless defined $maxtrace;
1158 =head2 SETTING UP THE DEBUGGER GREETING
1160 The debugger I<greeting> helps to inform the user how many debuggers are
1161 running, and whether the current debugger is the primary or a child.
1163 If we are the primary, we just hang onto our pid so we'll have it when
1164 or if we start a child debugger. If we are a child, we'll set things up
1165 so we'll have a unique greeting and so the parent will give us our own
1168 We save the current contents of the C<PERLDB_PIDS> environment variable
1169 because we mess around with it. We'll also need to hang onto it because
1170 we'll need it if we restart.
1172 Child debuggers make a label out of the current PID structure recorded in
1173 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1174 yet so the parent will give them one later via C<resetterm()>.
1178 # Save the current contents of the environment; we're about to
1179 # much with it. We'll need this if we have to restart.
1180 use vars qw($ini_pids);
1181 $ini_pids = $ENV{PERLDB_PIDS};
1183 use vars qw ($pids $term_pid);
1185 if ( defined $ENV{PERLDB_PIDS} ) {
1187 # We're a child. Make us a label out of the current PID structure
1188 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
1189 # a term yet so the parent will give us one later via resetterm().
1191 my $env_pids = $ENV{PERLDB_PIDS};
1192 $pids = "[$env_pids]";
1194 # Unless we are on OpenVMS, all programs under the DCL shell run under
1197 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1201 $ENV{PERLDB_PIDS} .= "->$$";
1205 } ## end if (defined $ENV{PERLDB_PIDS...
1208 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
1209 # child debugger, and mark us as the parent, so we'll know to set up
1210 # more TTY's is we have to.
1211 $ENV{PERLDB_PIDS} = "$$";
1216 use vars qw($pidprompt);
1219 # Sets up $emacs as a synonym for $slave_editor.
1220 our ($slave_editor);
1221 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1223 =head2 READING THE RC FILE
1225 The debugger will read a file of initialization options if supplied. If
1226 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1230 # As noted, this test really doesn't check accurately that the debugger
1231 # is running at a terminal or not.
1233 use vars qw($rcfile);
1235 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1236 # this is the wrong metric!
1237 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
1242 The debugger does a safety test of the file to be read. It must be owned
1243 either by the current user or root, and must only be writable by the owner.
1247 # This wraps a safety test around "do" to read and evaluate the init file.
1249 # This isn't really safe, because there's a race
1250 # between checking and opening. The solution is to
1251 # open and fstat the handle, but then you have to read and
1252 # eval the contents. But then the silly thing gets
1253 # your lexical scope, which is unfortunate at best.
1257 # Just exactly what part of the word "CORE::" don't you understand?
1258 local $SIG{__WARN__};
1259 local $SIG{__DIE__};
1261 unless ( is_safe_file($file) ) {
1262 CORE::warn <<EO_GRIPE;
1263 perldb: Must not source insecure rcfile $file.
1264 You or the superuser must be the owner, and it must not
1265 be writable by anyone but its owner.
1268 } ## end unless (is_safe_file($file...
1271 CORE::warn("perldb: couldn't parse $file: $@") if $@;
1272 } ## end sub safe_do
1274 # This is the safety test itself.
1276 # Verifies that owner is either real user or superuser and that no
1277 # one but owner may write to it. This function is of limited use
1278 # when called on a path instead of upon a handle, because there are
1279 # no guarantees that filename (by dirent) whose file (by ino) is
1280 # eventually accessed is the same as the one tested.
1281 # Assumes that the file's existence is not in doubt.
1284 stat($path) || return; # mysteriously vaporized
1285 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
1287 return 0 if $uid != 0 && $uid != $<;
1288 return 0 if $mode & 022;
1290 } ## end sub is_safe_file
1292 # If the rcfile (whichever one we decided was the right one to read)
1293 # exists, we safely do it.
1295 safe_do("./$rcfile");
1298 # If there isn't one here, try the user's home directory.
1299 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
1300 safe_do("$ENV{HOME}/$rcfile");
1303 # Else try the login directory.
1304 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
1305 safe_do("$ENV{LOGDIR}/$rcfile");
1308 # If the PERLDB_OPTS variable has options in it, parse those out next.
1309 if ( defined $ENV{PERLDB_OPTS} ) {
1310 parse_options( $ENV{PERLDB_OPTS} );
1315 The last thing we do during initialization is determine which subroutine is
1316 to be used to obtain a new terminal when a new debugger is started. Right now,
1317 the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
1322 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1323 # Works if you're running an xterm or xterm-like window, or you're on
1324 # OS/2, or on Mac OS X. This may need some expansion.
1326 if (not defined &get_fork_TTY) # only if no routine exists
1328 if ( defined $remoteport ) {
1329 # Expect an inetd-like server
1330 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1332 elsif (defined $ENV{TERM} # If we know what kind
1333 # of terminal this is,
1334 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1335 and defined $ENV{DISPLAY} # and what display it's on,
1338 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1340 elsif ( $ENV{TMUX} ) {
1341 *get_fork_TTY = \&tmux_get_fork_TTY;
1343 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1344 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1346 elsif ( $^O eq 'darwin' # If this is Mac OS X
1347 and defined $ENV{TERM_PROGRAM} # and we're running inside
1348 and $ENV{TERM_PROGRAM}
1349 eq 'Apple_Terminal' # Terminal.app
1352 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1354 } ## end if (not defined &get_fork_TTY...
1356 # untaint $^O, which may have been tainted by the last statement.
1357 # see bug [perl #24674]
1361 # Here begin the unreadable code. It needs fixing.
1363 =head2 RESTART PROCESSING
1365 This section handles the restart command. When the C<R> command is invoked, it
1366 tries to capture all of the state it can into environment variables, and
1367 then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1368 if C<PERLDB_RESTART> is there; if so, we reload all the information that
1369 the R command stuffed into the environment variables.
1371 PERLDB_RESTART - flag only, contains no restart data itself.
1372 PERLDB_HIST - command history, if it's available
1373 PERLDB_ON_LOAD - breakpoints set by the rc file
1374 PERLDB_POSTPONE - subs that have been loaded/not executed,
1376 PERLDB_VISITED - files that had breakpoints
1377 PERLDB_FILE_... - breakpoints for a file
1378 PERLDB_OPT - active options
1379 PERLDB_INC - the original @INC
1380 PERLDB_PRETYPE - preprompt debugger actions
1381 PERLDB_PRE - preprompt Perl code
1382 PERLDB_POST - post-prompt Perl code
1383 PERLDB_TYPEAHEAD - typeahead captured by readline()
1385 We chug through all these variables and plug the values saved in them
1386 back into the appropriate spots in the debugger.
1390 use vars qw(%postponed_file @typeahead);
1392 our (@hist, @truehist);
1394 sub _restore_shared_globals_after_restart
1396 @hist = get_list('PERLDB_HIST');
1397 %break_on_load = get_list("PERLDB_ON_LOAD");
1398 %postponed = get_list("PERLDB_POSTPONE");
1402 share(%break_on_load);
1406 sub _restore_breakpoints_and_actions {
1408 my @had_breakpoints = get_list("PERLDB_VISITED");
1410 for my $file_idx ( 0 .. $#had_breakpoints ) {
1411 my $filename = $had_breakpoints[$file_idx];
1412 my %pf = get_list("PERLDB_FILE_$file_idx");
1413 $postponed_file{ $filename } = \%pf if %pf;
1414 my @lines = sort {$a <=> $b} keys(%pf);
1415 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1416 for my $line_idx (0 .. $#lines) {
1417 _set_breakpoint_enabled_status(
1420 ($enabled_statuses[$line_idx] ? 1 : ''),
1428 sub _restore_options_after_restart
1430 my %options_map = get_list("PERLDB_OPT");
1432 while ( my ( $opt, $val ) = each %options_map ) {
1433 $val =~ s/[\\\']/\\$1/g;
1434 parse_options("$opt'$val'");
1440 sub _restore_globals_after_restart
1442 # restore original @INC
1443 @INC = get_list("PERLDB_INC");
1446 # return pre/postprompt actions and typeahead buffer
1447 $pretype = [ get_list("PERLDB_PRETYPE") ];
1448 $pre = [ get_list("PERLDB_PRE") ];
1449 $post = [ get_list("PERLDB_POST") ];
1450 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1456 if ( exists $ENV{PERLDB_RESTART} ) {
1458 # We're restarting, so we don't need the flag that says to restart anymore.
1459 delete $ENV{PERLDB_RESTART};
1462 _restore_shared_globals_after_restart();
1464 _restore_breakpoints_and_actions();
1467 _restore_options_after_restart();
1469 _restore_globals_after_restart();
1470 } ## end if (exists $ENV{PERLDB_RESTART...
1472 =head2 SETTING UP THE TERMINAL
1474 Now, we'll decide how the debugger is going to interact with the user.
1475 If there's no TTY, we set the debugger to run non-stop; there's not going
1476 to be anyone there to enter commands.
1480 use vars qw($notty $console $tty $LINEINFO);
1481 use vars qw($lineinfo $doccmd);
1485 # Local autoflush to avoid rt#116769,
1486 # as calling IO::File methods causes an unresolvable loop
1487 # that results in debugger failure.
1489 my $o = select($_[0]);
1501 If there is a TTY, we have to determine who it belongs to before we can
1502 proceed. If this is a slave editor or graphical debugger (denoted by
1503 the first command-line switch being '-emacs'), we shift this off and
1504 set C<$rl> to 0 (XXX ostensibly to do straight reads).
1510 # Is Perl being run from a slave editor or graphical debugger?
1511 # If so, don't use readline, and set $slave_editor = 1.
1512 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1517 #require Term::ReadLine;
1521 We then determine what the console should be on various systems:
1525 =item * Cygwin - We use C<stdin> instead of a separate device.
1529 if ( $^O eq 'cygwin' ) {
1531 # /dev/tty is binary. use stdin for textmode
1535 =item * Unix - use F</dev/tty>.
1539 elsif ( -e "/dev/tty" ) {
1540 $console = "/dev/tty";
1543 =item * Windows or MSDOS - use C<con>.
1547 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
1551 =item * VMS - use C<sys$command>.
1557 # everything else is ...
1558 $console = "sys\$command";
1565 Several other systems don't use a specific console. We C<undef $console>
1566 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1567 with a slave editor).
1571 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1573 # /dev/tty is binary. use stdin for textmode
1577 if ( $^O eq 'NetWare' ) {
1579 # /dev/tty is binary. use stdin for textmode
1583 # In OS/2, we need to use STDIN to get textmode too, even though
1584 # it pretty much looks like Unix otherwise.
1585 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1592 If there is a TTY hanging around from a parent, we use that as the console.
1596 $console = $tty if defined $tty;
1598 =head2 SOCKET HANDLING
1600 The debugger is capable of opening a socket and carrying out a debugging
1601 session over the socket.
1603 If C<RemotePort> was defined in the options, the debugger assumes that it
1604 should try to start a debugging session on that port. It builds the socket
1605 and then tries to connect the input and output filehandles to it.
1609 # Handle socket stuff.
1611 if ( defined $remoteport ) {
1613 # If RemotePort was defined in the options, connect input and output
1615 $IN = $OUT = connect_remoteport();
1616 } ## end if (defined $remoteport)
1620 If no C<RemotePort> was defined, and we want to create a TTY on startup,
1621 this is probably a situation where multiple debuggers are running (for example,
1622 a backticked command that starts up another debugger). We create a new IN and
1623 OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1631 # Two debuggers running (probably a system or a backtick that invokes
1632 # the debugger itself under the running one). create a new IN and OUT
1633 # filehandle, and do the necessary mojo to create a new tty if we
1634 # know how, and we can.
1635 create_IN_OUT(4) if $CreateTTY & 4;
1638 # If we have a console, check to see if there are separate ins and
1639 # outs to open. (They are assumed identical if not.)
1641 my ( $i, $o ) = split /,/, $console;
1642 $o = $i unless defined $o;
1644 # read/write on in, or just read, or read on STDIN.
1646 || open( IN, "<$i" )
1647 || open( IN, "<&STDIN" );
1649 # read/write/create/clobber out, or write/create/clobber out,
1650 # or merge with STDERR, or merge with STDOUT.
1652 || open( OUT, ">$o" )
1653 || open( OUT, ">&STDERR" )
1654 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1656 } ## end if ($console)
1657 elsif ( not defined $console ) {
1659 # No console. Open STDIN.
1660 open( IN, "<&STDIN" );
1662 # merge with STDERR, or with STDOUT.
1663 open( OUT, ">&STDERR" )
1664 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1665 $console = 'STDIN/OUT';
1666 } ## end elsif (not defined $console)
1668 # Keep copies of the filehandles so that when the pager runs, it
1669 # can close standard input without clobbering ours.
1670 if ($console or (not defined($console))) {
1674 } ## end elsif (from if(defined $remoteport))
1676 # Unbuffer DB::OUT. We need to see responses right away.
1679 # Line info goes to debugger output unless pointed elsewhere.
1680 # Pointing elsewhere makes it possible for slave editors to
1681 # keep track of file and position. We have both a filehandle
1682 # and a I/O description to keep track of.
1683 $LINEINFO = $OUT unless defined $LINEINFO;
1684 $lineinfo = $console unless defined $lineinfo;
1685 # share($LINEINFO); # <- unable to share globs
1690 To finish initialization, we show the debugger greeting,
1691 and then call the C<afterinit()> subroutine if there is one.
1695 # Show the debugger greeting.
1696 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1697 unless ($runnonstop) {
1700 if ( $term_pid eq '-1' ) {
1701 print $OUT "\nDaughter DB session started...\n";
1704 print $OUT "\nLoading DB routines from $header\n";
1707 $slave_editor ? "enabled" : "available", ".\n"
1710 "\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
1711 } ## end else [ if ($term_pid eq '-1')
1712 } ## end unless ($runnonstop)
1713 } ## end else [ if ($notty)
1715 # XXX This looks like a bug to me.
1716 # Why copy to @ARGS and then futz with @args?
1719 # Make sure backslashes before single quotes are stripped out, and
1720 # keep args unless they are numeric (XXX why?)
1721 # s/\'/\\\'/g; # removed while not justified understandably
1722 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
1725 # If there was an afterinit() sub defined, call it. It will get
1726 # executed in our scope, so it can fiddle with debugger globals.
1727 if ( defined &afterinit ) { # May be defined in $rcfile
1731 # Inform us about "Stack dump during die enabled ..." in dieLevel().
1732 use vars qw($I_m_init);
1736 ############################################################ Subroutines
1742 This gigantic subroutine is the heart of the debugger. Called before every
1743 statement, its job is to determine if a breakpoint has been reached, and
1744 stop if so; read commands from the user, parse them, and execute
1745 them, and then send execution off to the next statement.
1747 Note that the order in which the commands are processed is very important;
1748 some commands earlier in the loop will actually alter the C<$cmd> variable
1749 to create other commands to be executed later. This is all highly I<optimized>
1750 but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1751 see what's happening in any given command.
1755 # $cmd cannot be an our() variable unfortunately (possible perl bug?).
1785 sub _DB__determine_if_we_should_break
1787 # if we have something here, see if we should break.
1788 # $stop is lexical and local to this block - $action on the other hand
1793 && _is_breakpoint_enabled($filename, $line)
1794 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1797 # Stop if the stop criterion says to just stop.
1798 if ( $stop eq '1' ) {
1802 # It's a conditional stop; eval it in the user's context and
1803 # see if we should stop. If so, remove the one-time sigil.
1805 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1806 # The &-call is here to ascertain the mutability of @_.
1808 # If the breakpoint is temporary, then delete its enabled status.
1809 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1810 _cancel_breakpoint_temp_enabled_status($filename, $line);
1813 } ## end if ($dbline{$line} && ...
1816 sub _DB__is_finished {
1817 if ($finished and $level <= 1) {
1826 sub _DB__read_next_cmd
1830 # We have a terminal, or can get one ...
1835 # ... and it belongs to this PID or we get one for this PID ...
1836 if ($term_pid != $$) {
1840 # ... and we got a line of command input ...
1841 $cmd = DB::readline(
1842 "$pidprompt $tid DB"
1845 . ( '>' x $level ) . " "
1848 return defined($cmd);
1851 sub _DB__trim_command_and_return_first_component {
1854 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1855 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1857 my ($verb, $args) = $cmd =~ m{\A(\S*)\s*(.*)}s;
1859 $obj->cmd_verb($verb);
1860 $obj->cmd_args($args);
1865 sub _DB__handle_f_command {
1868 if ($file = $obj->cmd_args) {
1869 # help for no arguments (old-style was return from sub).
1872 "The old f command is now the r command.\n"; # hint
1873 print $OUT "The new f command switches filenames.\n";
1875 } ## end if (!$file)
1877 # if not in magic file list, try a close match.
1878 if ( !defined $main::{ '_<' . $file } ) {
1879 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
1881 $try = substr( $try, 2 );
1882 print $OUT "Choosing $try matching '$file':\n";
1885 } ## end if (($try) = grep(m#^_<.*$file#...
1886 } ## end if (!defined $main::{ ...
1888 # If not successfully switched now, we failed.
1889 if ( !defined $main::{ '_<' . $file } ) {
1890 print $OUT "No file matching '$file' is loaded.\n";
1894 # We switched, so switch the debugger internals around.
1895 elsif ( $file ne $filename ) {
1896 *dbline = $main::{ '_<' . $file };
1901 } ## end elsif ($file ne $filename)
1903 # We didn't switch; say we didn't.
1905 print $OUT "Already in $file.\n";
1913 sub _DB__handle_dot_command {
1917 if ($obj->_is_full('.')) {
1918 $incr = -1; # stay at current line
1920 # Reset everything to the old location.
1922 $filename = $filename_ini;
1923 *dbline = $main::{ '_<' . $filename };
1927 print_lineinfo($obj->position());
1934 sub _DB__handle_y_command {
1937 if (my ($match_level, $match_vars)
1938 = $obj->cmd_args =~ /\A(?:(\d*)\s*(.*))?\z/) {
1940 # See if we've got the necessary support.
1941 if (!eval { require PadWalker; PadWalker->VERSION(0.08) }) {
1945 ? "PadWalker module not found - please install\n"
1951 # Load up dumpvar if we don't have it. If we can, that is.
1952 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
1953 defined &main::dumpvar
1954 or print $OUT "dumpvar.pl not available.\n"
1957 # Got all the modules we need. Find them and print them.
1958 my @vars = split( ' ', $match_vars || '' );
1961 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 2 ) };
1963 # Oops. Can't find it.
1970 # Show the desired vars with dumplex().
1971 my $savout = select($OUT);
1973 # Have dumplex dump the lexicals.
1974 foreach my $key (sort keys %$h) {
1975 dumpvar::dumplex( $key, $h->{$key},
1976 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
1984 sub _DB__handle_c_command {
1987 my $i = $obj->cmd_args;
1989 if ($i =~ m#\A[\w:]*\z#) {
1991 # Hey, show's over. The debugged program finished
1992 # executing already.
1993 next CMD if _DB__is_finished();
1995 # Capture the place to put a one-time break.
1998 # Probably not needed, since we finish an interactive
1999 # sub-session anyway...
2000 # local $filename = $filename;
2001 # local *dbline = *dbline; # XXX Would this work?!
2003 # The above question wonders if localizing the alias
2004 # to the magic array works or not. Since it's commented
2005 # out, we'll just leave that to speculation for now.
2007 # If the "subname" isn't all digits, we'll assume it
2008 # is a subroutine name, and try to find it.
2009 if ( $subname =~ /\D/ ) { # subroutine name
2010 # Qualify it to the current package unless it's
2011 # already qualified.
2012 $subname = $package . "::" . $subname
2013 unless $subname =~ /::/;
2015 # find_sub will return "file:line_number" corresponding
2016 # to where the subroutine is defined; we call find_sub,
2017 # break up the return value, and assign it in one
2019 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2021 # Force the line number to be numeric.
2024 # If we got a line number, we found the sub.
2027 # Switch all the debugger's internals around so
2028 # we're actually working with that file.
2030 *dbline = $main::{ '_<' . $filename };
2032 # Mark that there's a breakpoint in this file.
2033 $had_breakpoints{$filename} |= 1;
2035 # Scan forward to the first executable line
2036 # after the 'sub whatever' line.
2039 while ($dbline[$_line_num] == 0 && $_line_num< $max)
2046 # We didn't find a sub by that name.
2048 print $OUT "Subroutine $subname not found.\n";
2051 } ## end if ($subname =~ /\D/)
2053 # At this point, either the subname was all digits (an
2054 # absolute line-break request) or we've scanned through
2055 # the code following the definition of the sub, looking
2056 # for an executable, which we may or may not have found.
2058 # If $i (which we set $subname from) is non-zero, we
2059 # got a request to break at some line somewhere. On
2060 # one hand, if there wasn't any real subroutine name
2061 # involved, this will be a request to break in the current
2062 # file at the specified line, so we have to check to make
2063 # sure that the line specified really is breakable.
2065 # On the other hand, if there was a subname supplied, the
2066 # preceding block has moved us to the proper file and
2067 # location within that file, and then scanned forward
2068 # looking for the next executable line. We have to make
2069 # sure that one was found.
2071 # On the gripping hand, we can't do anything unless the
2072 # current value of $i points to a valid breakable line.
2077 if ( $dbline[$i] == 0 ) {
2078 print $OUT "Line $i not breakable.\n";
2082 # Yes. Set up the one-time-break sigil.
2083 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2084 _enable_breakpoint_temp_enabled_status($filename, $i);
2087 # Turn off stack tracing from here up.
2088 for my $j (0 .. $stack_depth) {
2097 sub _DB__handle_forward_slash_command {
2100 # The pattern as a string.
2101 use vars qw($inpat);
2103 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2105 # Remove the final slash.
2106 $inpat =~ s:([^\\])/$:$1:;
2108 # If the pattern isn't null ...
2109 if ( $inpat ne "" ) {
2111 # Turn off warn and die processing for a bit.
2112 local $SIG{__DIE__};
2113 local $SIG{__WARN__};
2115 # Create the pattern.
2116 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2119 # Oops. Bad pattern. No biscuit.
2120 # Print the eval error and go back for more
2126 } ## end if ($inpat ne "")
2128 # Set up to stop on wrap-around.
2131 # Don't move off the current line.
2134 my $pat = $obj->pat;
2136 # Done in eval so nothing breaks if the pattern
2137 # does something weird.
2142 # Move ahead one line.
2145 # Wrap if we pass the last line.
2146 if ($start > $max) {
2150 # Stop if we have gotten back to this line again,
2151 last if ($start == $end);
2153 # A hit! (Note, though, that we are doing
2154 # case-insensitive matching. Maybe a qr//
2155 # expression would be better, so the user could
2156 # do case-sensitive matching if desired.
2157 if ($dbline[$start] =~ m/$pat/i) {
2158 if ($slave_editor) {
2159 # Handle proper escaping in the slave.
2160 print {$OUT} "\032\032$filename:$start:0\n";
2163 # Just print the line normally.
2164 print {$OUT} "$start:\t",$dbline[$start],"\n";
2166 # And quit since we found something.
2176 # If we wrapped, there never was a match.
2177 if ( $start == $end ) {
2178 print {$OUT} "/$pat/: not found\n";
2186 sub _DB__handle_question_mark_command {
2189 # ? - backward pattern search.
2190 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2192 # Get the pattern, remove trailing question mark.
2193 $inpat =~ s:([^\\])\?$:$1:;
2195 # If we've got one ...
2196 if ( $inpat ne "" ) {
2198 # Turn off die & warn handlers.
2199 local $SIG{__DIE__};
2200 local $SIG{__WARN__};
2201 eval '$inpat =~ m' . "\a$inpat\a";
2205 # Ouch. Not good. Print the error.
2210 } ## end if ($inpat ne "")
2212 # Where we are now is where to stop after wraparound.
2215 # Don't move away from this line.
2218 my $pat = $obj->pat;
2219 # Search inside the eval to prevent pattern badness
2227 # Wrap if we pass the first line.
2229 $start = $max if ($start <= 0);
2231 # Quit if we get back where we started,
2232 last if ($start == $end);
2235 if ($dbline[$start] =~ m/$pat/i) {
2236 if ($slave_editor) {
2237 # Yep, follow slave editor requirements.
2238 print $OUT "\032\032$filename:$start:0\n";
2241 # Yep, just print normally.
2242 print $OUT "$start:\t",$dbline[$start],"\n";
2251 # Say we failed if the loop never found anything,
2252 if ( $start == $end ) {
2253 print {$OUT} "?$pat?: not found\n";
2261 sub _DB__handle_restart_and_rerun_commands {
2264 my $cmd_cmd = $obj->cmd_verb;
2265 my $cmd_params = $obj->cmd_args;
2266 # R - restart execution.
2267 # rerun - controlled restart execution.
2268 if ($cmd_cmd eq 'rerun' or $cmd_params eq '') {
2270 # Change directory to the initial current working directory on
2271 # the script startup, so if the debugged program changed the
2272 # directory, then we will still be able to find the path to the
2273 # the program. (perl 5 RT #121509 ).
2274 chdir ($_initial_cwd);
2276 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
2278 # Close all non-system fds for a clean restart. A more
2279 # correct method would be to close all fds that were not
2280 # open when the process started, but this seems to be
2281 # hard. See "debugger 'R'estart and open database
2282 # connections" on p5p.
2284 my $max_fd = 1024; # default if POSIX can't be loaded
2285 if (eval { require POSIX }) {
2286 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
2289 if (defined $max_fd) {
2290 foreach ($^F+1 .. $max_fd-1) {
2291 next unless open FD_TO_CLOSE, "<&=$_";
2296 # And run Perl again. We use exec() to keep the
2297 # PID stable (and that way $ini_pids is still valid).
2298 exec(@args) or print {$OUT} "exec failed: $!\n";
2306 sub _DB__handle_run_command_in_pager_command {
2309 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
2310 if ( $pager =~ /^\|/ ) {
2312 # Default pager is into a pipe. Redirect I/O.
2313 open( SAVEOUT, ">&STDOUT" )
2314 || _db_warn("Can't save STDOUT");
2315 open( STDOUT, ">&OUT" )
2316 || _db_warn("Can't redirect STDOUT");
2317 } ## end if ($pager =~ /^\|/)
2320 # Not into a pipe. STDOUT is safe.
2321 open( SAVEOUT, ">&OUT" ) || _db_warn("Can't save DB::OUT");
2324 # Fix up environment to record we have less if so.
2327 unless ( $obj->piped(scalar ( open( OUT, $pager ) ) ) ) {
2329 # Couldn't open pipe to pager.
2330 _db_warn("Can't pipe output to '$pager'");
2331 if ( $pager =~ /^\|/ ) {
2333 # Redirect I/O back again.
2334 open( OUT, ">&STDOUT" ) # XXX: lost message
2335 || _db_warn("Can't restore DB::OUT");
2336 open( STDOUT, ">&SAVEOUT" )
2337 || _db_warn("Can't restore STDOUT");
2339 } ## end if ($pager =~ /^\|/)
2342 # Redirect I/O. STDOUT already safe.
2343 open( OUT, ">&STDOUT" ) # XXX: lost message
2344 || _db_warn("Can't restore DB::OUT");
2347 } ## end unless ($piped = open(OUT,...
2349 # Set up broken-pipe handler if necessary.
2350 $SIG{PIPE} = \&DB::catch
2352 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
2355 # Save current filehandle, and put it back.
2356 $obj->selected(scalar( select(OUT) ));
2357 # Don't put it back if pager was a pipe.
2358 if ($cmd !~ /\A\|\|/)
2360 select($obj->selected());
2364 # Trim off the pipe symbols and run the command now.
2365 $cmd =~ s#\A\|+\s*##;
2372 sub _DB__handle_m_command {
2375 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2380 # m expr - set up DB::eval to do the work
2381 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2382 $onetimeDump = 'methods'; # method output gets used there
2388 sub _DB__at_end_of_every_command {
2391 # At the end of every command:
2394 # Unhook the pipe mechanism now.
2395 if ( $pager =~ /^\|/ ) {
2397 # No error from the child.
2400 # we cannot warn here: the handle is missing --tchrist
2401 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
2403 # most of the $? crud was coping with broken cshisms
2404 # $? is explicitly set to 0, so this never runs.
2406 print SAVEOUT "Pager '$pager' failed: ";
2408 print SAVEOUT "shell returned -1\n";
2411 print SAVEOUT ( $? & 127 )
2412 ? " (SIG#" . ( $? & 127 ) . ")"
2413 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
2416 print SAVEOUT "status ", ( $? >> 8 ), "\n";
2420 # Reopen filehandle for our output (if we can) and
2421 # restore STDOUT (if we can).
2422 open( OUT, ">&STDOUT" ) || _db_warn("Can't restore DB::OUT");
2423 open( STDOUT, ">&SAVEOUT" )
2424 || _db_warn("Can't restore STDOUT");
2426 # Turn off pipe exception handler if necessary.
2427 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
2429 # Will stop ignoring SIGPIPE if done like nohup(1)
2430 # does SIGINT but Perl doesn't give us a choice.
2431 } ## end if ($pager =~ /^\|/)
2434 # Non-piped "pager". Just restore STDOUT.
2435 open( OUT, ">&SAVEOUT" ) || _db_warn("Can't restore DB::OUT");
2438 # Let Readline know about the new filehandles.
2439 reset_IN_OUT( \*IN, \*OUT );
2441 # Close filehandle pager was using, restore the normal one
2445 if ($obj->selected() ne "") {
2446 select($obj->selected);
2452 } ## end if ($piped)
2457 sub _DB__handle_watch_expressions
2461 if ( $DB::trace & 2 ) {
2462 for my $n (0 .. $#DB::to_watch) {
2463 $DB::evalarg = $DB::to_watch[$n];
2464 local $DB::onetimeDump; # Tell DB::eval() to not output results
2466 # Fix context DB::eval() wants to return an array, but
2467 # we need a scalar here.
2468 my ($val) = join( "', '", DB::eval(@_) );
2469 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
2472 if ( $val ne $DB::old_watch[$n] ) {
2474 # Yep! Show the difference, and fake an interrupt.
2476 print {$DB::OUT} <<EOP;
2477 Watchpoint $n:\t$DB::to_watch[$n] changed:
2478 old value:\t$DB::old_watch[$n]
2481 $DB::old_watch[$n] = $val;
2482 } ## end if ($val ne $old_watch...
2483 } ## end for my $n (0 ..
2484 } ## end if ($trace & 2)
2491 # 'v' is the value (i.e: method name or subroutine ref).
2492 # 's' is subroutine.
2499 '-' => { t => 'm', v => '_handle_dash_command', },
2500 '.' => { t => 's', v => \&_DB__handle_dot_command, },
2501 '=' => { t => 'm', v => '_handle_equal_sign_command', },
2502 'H' => { t => 'm', v => '_handle_H_command', },
2503 'S' => { t => 'm', v => '_handle_S_command', },
2504 'T' => { t => 'm', v => '_handle_T_command', },
2505 'W' => { t => 'm', v => '_handle_W_command', },
2506 'c' => { t => 's', v => \&_DB__handle_c_command, },
2507 'f' => { t => 's', v => \&_DB__handle_f_command, },
2508 'm' => { t => 's', v => \&_DB__handle_m_command, },
2509 'n' => { t => 'm', v => '_handle_n_command', },
2510 'p' => { t => 'm', v => '_handle_p_command', },
2511 'q' => { t => 'm', v => '_handle_q_command', },
2512 'r' => { t => 'm', v => '_handle_r_command', },
2513 's' => { t => 'm', v => '_handle_s_command', },
2514 'save' => { t => 'm', v => '_handle_save_command', },
2515 'source' => { t => 'm', v => '_handle_source_command', },
2516 't' => { t => 'm', v => '_handle_t_command', },
2517 'w' => { t => 'm', v => '_handle_w_command', },
2518 'x' => { t => 'm', v => '_handle_x_command', },
2519 'y' => { t => 's', v => \&_DB__handle_y_command, },
2520 (map { $_ => { t => 'm', v => '_handle_V_command_and_X_command', }, }
2522 (map { $_ => { t => 'm', v => '_handle_enable_disable_commands', }, }
2523 qw(enable disable)),
2525 { t => 's', v => \&_DB__handle_restart_and_rerun_commands, },
2527 (map { $_ => {t => 'm', v => '_handle_cmd_wrapper_commands' }, }
2528 qw(a A b B e E h i l L M o O v w W)),
2534 # lock the debugger and get the thread id for the prompt
2538 my ($prefix, $after, $infix);
2544 if ($ENV{PERL5DB_THREADED}) {
2545 $tid = eval { "[".threads->tid."]" };
2551 my $obj = DB::Obj->new(
2553 position => \$position,
2556 explicit_stop => \$explicit_stop,
2558 cmd_args => \$cmd_args,
2559 cmd_verb => \$cmd_verb,
2562 selected => \$selected,
2566 $obj->_DB_on_init__initialize_globals(@_);
2568 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
2569 # The code being debugged may have altered them.
2572 # Since DB::DB gets called after every line, we can use caller() to
2573 # figure out where we last were executing. Sneaky, eh? This works because
2574 # caller is returning all the extra information when called from the
2576 local ( $package, $filename, $line ) = caller;
2577 $filename_ini = $filename;
2579 # set up the context for DB::eval, so it can properly execute
2580 # code on behalf of the user. We add the package in so that the
2581 # code is eval'ed in the proper package (not in the debugger!).
2582 local $usercontext = _calc_usercontext($package);
2584 # Create an alias to the active file magical array to simplify
2586 local (*dbline) = $main::{ '_<' . $filename };
2588 # Last line in the program.
2591 # The &-call is here to ascertain the mutability of @_.
2592 &_DB__determine_if_we_should_break;
2594 # Preserve the current stop-or-not, and see if any of the W
2595 # (watch expressions) has changed.
2596 my $was_signal = $signal;
2598 # If we have any watch expressions ...
2599 _DB__handle_watch_expressions($obj);
2601 =head2 C<watchfunction()>
2603 C<watchfunction()> is a function that can be defined by the user; it is a
2604 function which will be run on each entry to C<DB::DB>; it gets the
2605 current package, filename, and line as its parameters.
2607 The watchfunction can do anything it likes; it is executing in the
2608 debugger's context, so it has access to all of the debugger's internal
2609 data structures and functions.
2611 C<watchfunction()> can control the debugger's actions. Any of the following
2612 will cause the debugger to return control to the user's program after
2613 C<watchfunction()> executes:
2619 Returning a false value from the C<watchfunction()> itself.
2623 Altering C<$single> to a false value.
2627 Altering C<$signal> to a false value.
2631 Turning off the C<4> bit in C<$trace> (this also disables the
2632 check for C<watchfunction()>. This can be done with
2640 # If there's a user-defined DB::watchfunction, call it with the
2641 # current package, filename, and line. The function executes in
2643 if ( $trace & 4 ) { # User-installed watch
2645 if watchfunction( $package, $filename, $line )
2648 and not( $trace & ~4 );
2649 } ## end if ($trace & 4)
2651 # Pick up any alteration to $signal in the watchfunction, and
2652 # turn off the signal now.
2653 $was_signal = $signal;
2656 =head2 GETTING READY TO EXECUTE COMMANDS
2658 The debugger decides to take control if single-step mode is on, the
2659 C<t> command was entered, or the user generated a signal. If the program
2660 has fallen off the end, we set things up so that entering further commands
2661 won't cause trouble, and we say that the program is over.
2665 # Make sure that we always print if asked for explicitly regardless
2666 # of $trace_to_depth .
2667 $explicit_stop = ($single || $was_signal);
2669 # Check to see if we should grab control ($single true,
2670 # trace set appropriately, or we got a signal).
2671 if ( $explicit_stop || ( $trace & 1 ) ) {
2672 $obj->_DB__grab_control(@_);
2673 } ## end if ($single || ($trace...
2677 If there's an action to be executed for the line we stopped at, execute it.
2678 If there are any preprompt actions, execute those as well.
2682 # If there's an action, do it now.
2685 # The &-call is here to ascertain the mutability of @_.
2689 # Are we nested another level (e.g., did we evaluate a function
2690 # that had a breakpoint in it at the debugger prompt)?
2691 if ( $single || $was_signal ) {
2693 # Yes, go down a level.
2694 local $level = $level + 1;
2696 # Do any pre-prompt actions.
2697 foreach $evalarg (@$pre) {
2698 # The &-call is here to ascertain the mutability of @_.
2702 # Complain about too much recursion if we passed the limit.
2704 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2707 # The line we're currently on. Set $incr to -1 to stay here
2708 # until we get a command that tells us to advance.
2710 $incr = -1; # for backward motion.
2712 # Tack preprompt debugger actions ahead of any actual input.
2713 @typeahead = ( @$pretype, @typeahead );
2715 =head2 WHERE ARE WE?
2717 XXX Relocate this section?
2719 The debugger normally shows the line corresponding to the current line of
2720 execution. Sometimes, though, we want to see the next line, or to move elsewhere
2721 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2723 C<$incr> controls by how many lines the I<current> line should move forward
2724 after a command is executed. If set to -1, this indicates that the I<current>
2725 line shouldn't change.
2727 C<$start> is the I<current> line. It is used for things like knowing where to
2728 move forwards or backwards from when doing an C<L> or C<-> command.
2730 C<$max> tells the debugger where the last line of the current file is. It's
2731 used to terminate loops most often.
2733 =head2 THE COMMAND LOOP
2735 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2742 The outer part of the loop, starting at the C<CMD> label. This loop
2743 reads a command and then executes it.
2747 The inner part of the loop, starting at the C<PIPE> label. This part
2748 is wholly contained inside the C<CMD> block and only executes a command.
2749 Used to handle commands running inside a pager.
2753 So why have two labels to restart the loop? Because sometimes, it's easier to
2754 have a command I<generate> another command and then re-execute the loop to do
2755 the new command. This is faster, but perhaps a bit more convoluted.
2759 # The big command dispatch loop. It keeps running until the
2760 # user yields up control again.
2762 # If we have a terminal for input, and we get something back
2763 # from readline(), keep on processing.
2766 while (_DB__read_next_cmd($tid))
2770 # ... try to execute the input as debugger commands.
2772 # Don't stop running.
2775 # No signal is active.
2778 # Handle continued commands (ending with \):
2779 if ($cmd =~ s/\\\z/\n/) {
2780 $cmd .= DB::readline(" cont: ");
2784 =head4 The null command
2786 A newline entered by itself means I<re-execute the last command>. We grab the
2787 command out of C<$laststep> (where it was recorded previously), and copy it
2788 back into C<$cmd> to be executed below. If there wasn't any previous command,
2789 we'll do nothing below (no command will match). If there was, we also save it
2790 in the command history and fall through to allow the command parsing to pick
2795 # Empty input means repeat the last command.
2799 chomp($cmd); # get rid of the annoying extra newline
2800 if (length($cmd) >= 2) {
2801 push( @hist, $cmd );
2803 push( @truehist, $cmd );
2807 # This is a restart point for commands that didn't arrive
2808 # via direct user input. It allows us to 'redo PIPE' to
2809 # re-execute command processing without reading a new command.
2811 _DB__trim_command_and_return_first_component($obj);
2813 =head3 COMMAND ALIASES
2815 The debugger can create aliases for commands (these are stored in the
2816 C<%alias> hash). Before a command is executed, the command loop looks it up
2817 in the alias hash and substitutes the contents of the alias for the command,
2818 completely replacing it.
2822 # See if there's an alias for the command, and set it up if so.
2823 if ( $alias{$cmd_verb} ) {
2825 # Squelch signal handling; we want to keep control here
2826 # if something goes loco during the alias eval.
2827 local $SIG{__DIE__};
2828 local $SIG{__WARN__};
2830 # This is a command, so we eval it in the DEBUGGER's
2831 # scope! Otherwise, we can't see the special debugger
2832 # variables, or get to the debugger's subs. (Well, we
2833 # _could_, but why make it even more complicated?)
2834 eval "\$cmd =~ $alias{$cmd_verb}";
2837 print $OUT "Couldn't evaluate '$cmd_verb' alias: $@";
2840 _DB__trim_command_and_return_first_component($obj);
2841 } ## end if ($alias{$cmd_verb})
2843 =head3 MAIN-LINE COMMANDS
2845 All of these commands work up to and after the program being debugged has
2850 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2851 try to execute further, cleaning any restart-related stuff out of the
2852 environment, and executing with the last value of C<$?>.
2856 # All of these commands were remapped in perl 5.8.0;
2857 # we send them off to the secondary dispatcher (see below).
2858 $obj->_handle_special_char_cmd_wrapper_commands;
2859 _DB__trim_command_and_return_first_component($obj);
2861 if (my $cmd_rec = $cmd_lookup{$cmd_verb}) {
2862 my $type = $cmd_rec->{t};
2863 my $val = $cmd_rec->{v};
2867 elsif ($type eq 's') {
2872 =head4 C<t> - trace [n]
2874 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2875 If level is specified, set C<$trace_to_depth>.
2877 =head4 C<S> - list subroutines matching/not matching a pattern
2879 Walks through C<%sub>, checking to see whether or not to print the name.
2881 =head4 C<X> - list variables in current package
2883 Since the C<V> command actually processes this, just change this to the
2884 appropriate C<V> command and fall through.
2886 =head4 C<V> - list variables
2888 Uses C<dumpvar.pl> to dump out the current values for selected variables.
2890 =head4 C<x> - evaluate and print an expression
2892 Hands the expression off to C<DB::eval>, setting it up to print the value
2893 via C<dumpvar.pl> instead of just printing it directly.
2895 =head4 C<m> - print methods
2897 Just uses C<DB::methods> to determine what methods are available.
2899 =head4 C<f> - switch files
2901 Switch to a different filename.
2903 =head4 C<.> - return to last-executed line.
2905 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2906 and then we look up the line in the magical C<%dbline> hash.
2908 =head4 C<-> - back one window
2910 We change C<$start> to be one window back; if we go back past the first line,
2911 we set it to be the first line. We ser C<$incr> to put us back at the
2912 currently-executing line, and then put a C<l $start +> (list one window from
2913 C<$start>) in C<$cmd> to be executed later.
2915 =head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
2917 In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2918 problems, most notably that the default case of several commands destroying
2919 the user's work in setting watchpoints, actions, etc. We wanted, however, to
2920 retain the old commands for those who were used to using them or who preferred
2921 them. At this point, we check for the new commands and call C<cmd_wrapper> to
2922 deal with them instead of processing them in-line.
2924 =head4 C<y> - List lexicals in higher scope
2926 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2927 above the current one and then displays then using C<dumpvar.pl>.
2929 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2931 All of the commands below this point don't work after the program being
2932 debugged has ended. All of them check to see if the program has ended; this
2933 allows the commands to be relocated without worrying about a 'line of
2934 demarcation' above which commands can be entered anytime, and below which
2937 =head4 C<n> - single step, but don't trace down into subs
2939 Done by setting C<$single> to 2, which forces subs to execute straight through
2940 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
2941 so a null command knows what to re-execute.
2943 =head4 C<s> - single-step, entering subs
2945 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
2946 subs. Also saves C<s> as C<$lastcmd>.
2948 =head4 C<c> - run continuously, setting an optional breakpoint
2950 Most of the code for this command is taken up with locating the optional
2951 breakpoint, which is either a subroutine name or a line number. We set
2952 the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2953 in this and all call levels above this one.
2955 =head4 C<r> - return from a subroutine
2957 For C<r> to work properly, the debugger has to stop execution again
2958 immediately after the return is executed. This is done by forcing
2959 single-stepping to be on in the call level above the current one. If
2960 we are printing return values when a C<r> is executed, set C<$doret>
2961 appropriately, and force us out of the command loop.
2963 =head4 C<T> - stack trace
2965 Just calls C<DB::print_trace>.
2967 =head4 C<w> - List window around current line.
2969 Just calls C<DB::cmd_w>.
2971 =head4 C<W> - watch-expression processing.
2973 Just calls C<DB::cmd_W>.
2975 =head4 C</> - search forward for a string in the source
2977 We take the argument and treat it as a pattern. If it turns out to be a
2978 bad one, we return the error we got from trying to C<eval> it and exit.
2979 If not, we create some code to do the search and C<eval> it so it can't
2984 _DB__handle_forward_slash_command($obj);
2986 =head4 C<?> - search backward for a string in the source
2988 Same as for C</>, except the loop runs backwards.
2992 _DB__handle_question_mark_command($obj);
2994 =head4 C<$rc> - Recall command
2996 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2997 that the terminal supports history). It finds the command required, puts it
2998 into C<$cmd>, and redoes the loop to execute it.
3002 # $rc - recall command.
3003 $obj->_handle_rc_recall_command;
3005 =head4 C<$sh$sh> - C<system()> command
3007 Calls the C<_db_system()> to handle the command. This keeps the C<STDIN> and
3008 C<STDOUT> from getting messed up.
3012 $obj->_handle_sh_command;
3014 =head4 C<$rc I<pattern> $rc> - Search command history
3016 Another command to manipulate C<@hist>: this one searches it with a pattern.
3017 If a command is found, it is placed in C<$cmd> and executed via C<redo>.
3021 $obj->_handle_rc_search_history_command;
3023 =head4 C<$sh> - Invoke a shell
3025 Uses C<_db_system()> to invoke a shell.
3029 =head4 C<$sh I<command>> - Force execution of a command in a shell
3031 Like the above, but the command is passed to the shell. Again, we use
3032 C<_db_system()> to avoid problems with C<STDIN> and C<STDOUT>.
3034 =head4 C<H> - display commands in history
3036 Prints the contents of C<@hist> (if any).
3038 =head4 C<man, doc, perldoc> - look up documentation
3040 Just calls C<runman()> to print the appropriate document.
3044 $obj->_handle_doc_command;
3048 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3049 the bottom of the loop.
3051 =head4 C<=> - define command alias
3053 Manipulates C<%alias> to add or list command aliases.
3055 =head4 C<source> - read commands from a file.
3057 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3060 =head4 C<enable> C<disable> - enable or disable breakpoints
3062 This enables or disables breakpoints.
3064 =head4 C<save> - send current history to a file
3066 Takes the complete history, (not the shrunken version you see with C<H>),
3067 and saves it to the given filename, so it can be replayed using C<source>.
3069 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3071 =head4 C<R> - restart
3073 Restart the debugger session.
3075 =head4 C<rerun> - rerun the current session
3077 Return to any given position in the B<true>-history list
3079 =head4 C<|, ||> - pipe output through the pager.
3081 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
3082 (the program's standard output). For C<||>, we only save C<OUT>. We open a
3083 pipe to the pager (restoring the output filehandles if this fails). If this
3084 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3085 set C<$signal>, sending us back into the debugger.
3087 We then trim off the pipe symbols and C<redo> the command loop at the
3088 C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3093 # || - run command in the pager, with output to DB::OUT.
3094 _DB__handle_run_command_in_pager_command($obj);
3096 =head3 END OF COMMAND PARSING
3098 Anything left in C<$cmd> at this point is a Perl expression that we want to
3099 evaluate. We'll always evaluate in the user's context, and fully qualify
3100 any variables we might want to address in the C<DB> package.
3106 # trace an expression
3107 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3109 # Make sure the flag that says "the debugger's running" is
3110 # still on, to make sure we get control again.
3111 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
3113 # Run *our* eval that executes in the caller's context.
3114 # The &-call is here to ascertain the mutability of @_.
3117 # Turn off the one-time-dump stuff now.
3119 $onetimeDump = undef;
3120 $onetimedumpDepth = undef;
3122 elsif ( $term_pid == $$ ) {
3123 eval { # May run under miniperl, when not available...
3128 # XXX If this is the master pid, print a newline.
3131 } ## end while (($term || &setterm...
3133 =head3 POST-COMMAND PROCESSING
3135 After each command, we check to see if the command output was piped anywhere.
3136 If so, we go through the necessary code to unhook the pipe and go back to
3137 our standard filehandles for input and output.
3142 _DB__at_end_of_every_command($obj);
3145 =head3 COMMAND LOOP TERMINATION
3147 When commands have finished executing, we come here. If the user closed the
3148 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3149 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3150 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3151 The interpreter will then execute the next line and then return control to us
3156 # No more commands? Quit.
3157 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
3159 # Evaluate post-prompt commands.
3160 foreach $evalarg (@$post) {
3161 # The &-call is here to ascertain the mutability of @_.
3164 } # if ($single || $signal)
3166 # Put the user's globals back where you found them.
3167 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
3171 # Because DB::Obj is used above,
3173 # my $obj = DB::Obj->new(
3175 # The following package declaration must come before that,
3176 # or else runtime errors will occur with
3178 # PERLDB_OPTS="autotrace nonstop"
3188 my $self = bless {}, $class;
3196 my ($self, $args) = @_;
3198 %{$self} = (%$self, %$args);
3205 foreach my $slot_name (qw(
3206 after explicit_stop infix pat piped position prefix selected cmd_verb
3209 my $slot = $slot_name;
3214 ${ $self->{$slot} } = shift;
3217 return ${ $self->{$slot} };
3220 *{"append_to_$slot"} = sub {
3224 return $self->$slot($self->$slot . $s);
3229 sub _DB_on_init__initialize_globals
3233 # Check for whether we should be running continuously or not.
3234 # _After_ the perl program is compiled, $single is set to 1:
3235 if ( $single and not $second_time++ ) {
3237 # Options say run non-stop. Run until we get an interrupt.
3238 if ($runnonstop) { # Disable until signal
3239 # If there's any call stack in place, turn off single
3240 # stepping into subs throughout the stack.
3241 for my $i (0 .. $stack_depth) {
3245 # And we are now no longer in single-step mode.
3248 # If we simply returned at this point, we wouldn't get
3249 # the trace info. Fall on through.
3251 } ## end if ($runnonstop)
3253 elsif ($ImmediateStop) {
3255 # We are supposed to stop here; XXX probably a break.
3256 $ImmediateStop = 0; # We've processed it; turn it off
3257 $signal = 1; # Simulate an interrupt to force
3258 # us into the command loop
3260 } ## end if ($single and not $second_time...
3262 # If we're in single-step mode, or an interrupt (real or fake)
3263 # has occurred, turn off non-stop mode.
3264 $runnonstop = 0 if $single or $signal;
3269 sub _my_print_lineinfo
3271 my ($self, $i, $incr_pos) = @_;
3274 # Print it indented if tracing is on.
3275 DB::print_lineinfo( ' ' x $stack_depth,
3276 "$i:\t$DB::dbline[$i]" . $self->after );
3279 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3284 return $DB::dbline[$line];
3288 my ($self, $letter) = @_;
3290 return ($DB::cmd eq $letter);
3293 sub _DB__grab_control
3297 # Yes, grab control.
3298 if ($slave_editor) {
3300 # Tell the editor to update its position.
3301 $self->position("\032\032${DB::filename}:$line:0\n");
3302 DB::print_lineinfo($self->position());
3307 Special check: if we're in package C<DB::fake>, we've gone through the
3308 C<END> block at least once. We set up everything so that we can continue
3309 to enter commands and have a valid context to be in.
3313 elsif ( $DB::package eq 'DB::fake' ) {
3315 # Fallen off the end already.
3320 DB::print_help(<<EOP);
3321 Debugged program terminated. Use B<q> to quit or B<R> to restart,
3322 use B<o> I<inhibit_exit> to avoid stopping after program termination,
3323 B<h q>, B<h R> or B<h o> to get additional info.
3326 # Set the DB::eval context appropriately.
3327 # At program termination disable any user actions.
3328 $DB::action = undef;
3330 $DB::package = 'main';
3331 $DB::usercontext = DB::_calc_usercontext($DB::package);
3332 } ## end elsif ($package eq 'DB::fake')
3336 If the program hasn't finished executing, we scan forward to the
3337 next executable line, print that out, build the prompt from the file and line
3338 number information, and print that.
3345 # Still somewhere in the midst of execution. Set up the
3347 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3348 # Perl 5 ones (sorry, we don't print Klingon
3351 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
3352 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
3353 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
3355 # Break up the prompt if it's really long.
3356 if ( length($self->prefix()) > 30 ) {
3357 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
3359 $self->infix(":\t");
3362 $self->infix("):\t");
3364 $self->prefix . $line. $self->infix
3365 . $self->_curr_line . $self->after
3369 # Print current line info, indenting if necessary.
3370 $self->_my_print_lineinfo($line, $self->position);
3373 my $line_i = sub { return $DB::dbline[$i]; };
3375 # Scan forward, stopping at either the end or the next
3377 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
3380 # Drop out on null statements, block closers, and comments.
3381 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
3383 # Drop out if the user interrupted us.
3386 # Append a newline if the line doesn't have one. Can happen
3387 # in eval'ed text, for instance.
3388 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
3390 # Next executable line.
3391 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
3393 $self->append_to_position($incr_pos);
3394 $self->_my_print_lineinfo($i, $incr_pos);
3395 } ## end for ($i = $line + 1 ; $i...
3396 } ## end else [ if ($slave_editor)
3401 sub _handle_t_command {
3404 my $levels = $self->cmd_args();
3406 if ((!length($levels)) or ($levels !~ /\D/)) {
3409 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
3410 print {$OUT} "Trace = "
3412 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3421 sub _handle_S_command {
3424 if (my ($print_all_subs, $should_reverse, $Spatt)
3425 = $self->cmd_args =~ /\A((!)?(.+))?\z/) {
3426 # $Spatt is the pattern (if any) to use.
3428 my $Srev = defined $should_reverse;
3429 # No args - print all subs.
3430 my $Snocheck = !defined $print_all_subs;
3432 # Need to make these sane here.
3436 # Search through the debugger's magical hash of subs.
3437 # If $nocheck is true, just print the sub name.
3438 # Otherwise, check it against the pattern. We then use
3439 # the XOR trick to reverse the condition as required.
3440 foreach $subname ( sort( keys %sub ) ) {
3441 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
3442 print $OUT $subname, "\n";
3451 sub _handle_V_command_and_X_command {
3454 $DB::cmd =~ s/^X\b/V $DB::package/;
3456 # Bare V commands get the currently-being-debugged package
3458 if ($self->_is_full('V')) {
3459 $DB::cmd = "V $DB::package";
3462 # V - show variables in package.
3463 if (my ($new_packname, $new_vars_str) =
3464 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
3466 # Save the currently selected filehandle and
3467 # force output to debugger's filehandle (dumpvar
3468 # just does "print" for output).
3469 my $savout = select($OUT);
3471 # Grab package name and variables to dump.
3472 $packname = $new_packname;
3473 my @vars = split( ' ', $new_vars_str );
3475 # If main::dumpvar isn't here, get it.
3476 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
3477 if ( defined &main::dumpvar ) {
3479 # We got it. Turn off subroutine entry/exit messages
3480 # for the moment, along with return values.
3484 # must detect sigpipe failures - not catching
3485 # then will cause the debugger to die.
3489 defined $option{dumpDepth}
3490 ? $option{dumpDepth}
3491 : -1, # assume -1 unless specified
3496 # The die doesn't need to include the $@, because
3497 # it will automatically get propagated for us.
3499 die unless $@ =~ /dumpvar print failed/;
3501 } ## end if (defined &main::dumpvar)
3504 # Couldn't load dumpvar.
3505 print $OUT "dumpvar.pl not available.\n";
3508 # Restore the output filehandle, and go round again.
3516 sub _handle_dash_command {
3519 if ($self->_is_full('-')) {
3521 # back up by a window; go to 1 if back too far.
3522 $start -= $incr + $window + 1;
3523 $start = 1 if $start <= 0;
3524 $incr = $window - 1;
3526 # Generate and execute a "l +" command (handled below).
3527 $DB::cmd = 'l ' . ($start) . '+';
3533 sub _n_or_s_commands_generic {
3534 my ($self, $new_val) = @_;
3536 next CMD if DB::_DB__is_finished();
3538 # Single step, but don't enter subs.
3541 # Save for empty command (repeat last).
3542 $laststep = $DB::cmd;
3547 my ($self, $letter, $new_val) = @_;
3549 if ($self->_is_full($letter)) {
3550 $self->_n_or_s_commands_generic($new_val);
3553 $self->_n_or_s_and_arg_commands_generic($letter, $new_val);
3559 sub _handle_n_command {
3562 return $self->_n_or_s('n', 2);
3565 sub _handle_s_command {
3568 return $self->_n_or_s('s', 1);
3571 sub _handle_r_command {
3574 # r - return from the current subroutine.
3575 if ($self->_is_full('r')) {
3577 # Can't do anything if the program's over.
3578 next CMD if DB::_DB__is_finished();
3580 # Turn on stack trace.
3581 $stack[$stack_depth] |= 1;
3583 # Print return value unless the stack is empty.
3584 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
3591 sub _handle_T_command {
3594 if ($self->_is_full('T')) {
3595 DB::print_trace( $OUT, 1 ); # skip DB
3602 sub _handle_w_command {
3605 DB::cmd_w( 'w', $self->cmd_args() );
3611 sub _handle_W_command {
3614 if (my $arg = $self->cmd_args) {
3615 DB::cmd_W( 'W', $arg );
3622 sub _handle_rc_recall_command {
3625 # $rc - recall command.
3626 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
3628 # No arguments, take one thing off history.
3629 pop(@hist) if length($DB::cmd) > 1;
3631 # Relative (- found)?
3632 # Y - index back from most recent (by 1 if bare minus)
3633 # N - go to that particular command slot or the last
3634 # thing if nothing following.
3637 scalar($minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist ))
3640 # Pick out the command desired.
3641 $DB::cmd = $hist[$self->cmd_verb];
3643 # Print the command to be executed and restart the loop
3644 # with that command in the buffer.
3645 print {$OUT} $DB::cmd, "\n";
3652 sub _handle_rc_search_history_command {
3655 # $rc pattern $rc - find a command in the history.
3656 if (my ($arg) = $DB::cmd =~ /\A$rc([^$rc].*)\z/) {
3658 # Create the pattern to use.
3662 # Toss off last entry if length is >1 (and it always is).
3663 pop(@hist) if length($DB::cmd) > 1;
3667 # Look backward through the history.
3669 for ( $i = $#hist ; $i ; --$i ) {
3670 # Stop if we find it.
3671 last SEARCH_HIST if $hist[$i] =~ /$pat/;
3677 print $OUT "No such command!\n\n";
3681 # Found it. Put it in the buffer, print it, and process it.
3682 $DB::cmd = $hist[$i];
3683 print $OUT $DB::cmd, "\n";
3690 sub _handle_H_command {
3693 if ($self->cmd_args =~ m#\A\*#) {
3694 @hist = @truehist = ();
3695 print $OUT "History cleansed\n";
3699 if (my ($num) = $self->cmd_args =~ /\A(?:-(\d+))?/) {
3701 # Anything other than negative numbers is ignored by
3702 # the (incorrect) pattern, so this test does nothing.
3703 $end = $num ? ( $#hist - $num ) : 0;
3705 # Set to the minimum if less than zero.
3706 $hist = 0 if $hist < 0;
3708 # Start at the end of the array.
3709 # Stay in while we're still above the ending value.
3710 # Tick back by one each time around the loop.
3713 for ( $i = $#hist ; $i > $end ; $i-- ) {
3715 # Print the command unless it has no arguments.
3716 print $OUT "$i: ", $hist[$i], "\n"
3717 unless $hist[$i] =~ /^.?$/;
3726 sub _handle_doc_command {
3729 # man, perldoc, doc - show manual pages.
3731 = $DB::cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
3732 DB::runman($man_page);
3739 sub _handle_p_command {
3742 my $print_cmd = 'print {$DB::OUT} ';
3743 # p - print (no args): print $_.
3744 if ($self->_is_full('p')) {
3745 $DB::cmd = $print_cmd . '$_';
3748 # p - print the given expression.
3749 $DB::cmd =~ s/\Ap\b/$print_cmd /;
3755 sub _handle_equal_sign_command {
3758 if ($DB::cmd =~ s/\A=\s*//) {
3760 if ( length $DB::cmd == 0 ) {
3762 # No args, get current aliases.
3763 @keys = sort keys %alias;
3765 elsif ( my ( $k, $v ) = ( $DB::cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3767 # Creating a new alias. $k is alias name, $v is
3770 # can't use $_ or kill //g state
3771 for my $x ( $k, $v ) {
3773 # Escape "alarm" characters.
3777 # Substitute key for value, using alarm chars
3778 # as separators (which is why we escaped them in
3780 $alias{$k} = "s\a$k\a$v\a";
3782 # Turn off standard warn and die behavior.
3783 local $SIG{__DIE__};
3784 local $SIG{__WARN__};
3787 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3789 # Nope. Bad alias. Say so and get out.
3790 print $OUT "Can't alias $k to $v: $@\n";
3795 # We'll only list the new one.
3797 } ## end elsif (my ($k, $v) = ($DB::cmd...
3799 # The argument is the alias to list.
3807 # Messy metaquoting: Trim the substitution code off.
3808 # We use control-G as the delimiter because it's not
3809 # likely to appear in the alias.
3810 if ( ( my $v = $alias{$k} ) =~ s
\as\a$k\a(.*)\a$
\a1
\a ) {
3813 print $OUT "$k\t= $1\n";
3815 elsif ( defined $alias{$k} ) {
3817 # Couldn't trim it off; just print the alias code.
3818 print $OUT "$k\t$alias{$k}\n";
3823 print "No alias for $k\n";
3825 } ## end for my $k (@keys)
3832 sub _handle_source_command {
3835 # source - read commands from a file (or pipe!) and execute.
3836 if (my $sourced_fn = $self->cmd_args) {
3837 if ( open my $fh, $sourced_fn ) {
3839 # Opened OK; stick it in the list of file handles.
3845 DB::_db_warn("Can't execute '$sourced_fn': $!\n");
3853 sub _handle_enable_disable_commands {
3856 my $which_cmd = $self->cmd_verb;
3857 my $position = $self->cmd_args;
3859 if ($position !~ /\s/) {
3860 my ($fn, $line_num);
3861 if ($position =~ m{\A\d+\z})
3863 $fn = $DB::filename;
3864 $line_num = $position;
3866 elsif (my ($new_fn, $new_line_num)
3867 = $position =~ m{\A(.*):(\d+)\z}) {
3868 ($fn, $line_num) = ($new_fn, $new_line_num);
3872 DB::_db_warn("Wrong spec for enable/disable argument.\n");
3876 if (DB::_has_breakpoint_data_ref($fn, $line_num)) {
3877 DB::_set_breakpoint_enabled_status($fn, $line_num,
3878 ($which_cmd eq 'enable' ? 1 : '')
3882 DB::_db_warn("No breakpoint set at ${fn}:${line_num}\n");
3892 sub _handle_save_command {
3895 if (my $new_fn = $self->cmd_args) {
3896 my $filename = $new_fn || '.perl5dbrc'; # default?
3897 if ( open my $fh, '>', $filename ) {
3899 # chomp to remove extraneous newlines from source'd files
3900 chomp( my @truelist =
3901 map { m/\A\s*(save|source)/ ? "#$_" : $_ }
3903 print {$fh} join( "\n", @truelist );
3904 print "commands saved in $filename\n";
3907 DB::_db_warn("Can't save debugger commands in '$new_fn': $!\n");
3915 sub _n_or_s_and_arg_commands_generic {
3916 my ($self, $letter, $new_val) = @_;
3918 # s - single-step. Remember the last command was 's'.
3919 if ($DB::cmd =~ s#\A\Q$letter\E\s#\$DB::single = $new_val;\n#) {
3920 $laststep = $letter;
3926 sub _handle_sh_command {
3929 # $sh$sh - run a shell command (if it's all ASCII).
3930 # Can't run shell commands with Unicode in the debugger, hmm.
3931 my $my_cmd = $DB::cmd;
3932 if ($my_cmd =~ m#\A$sh#gms) {
3934 if ($my_cmd =~ m#\G\z#cgms) {
3935 # Run the user's shell. If none defined, run Bourne.
3936 # We resume execution when the shell terminates.
3937 DB::_db_system( $ENV{SHELL} || "/bin/sh" );
3940 elsif ($my_cmd =~ m#\G$sh\s*(.*)#cgms) {
3945 elsif ($my_cmd =~ m#\G\s*(.*)#cgms) {
3946 DB::_db_system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3952 sub _handle_x_command {
3955 if ($DB::cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
3956 $onetimeDump = 'dump'; # main::dumpvar shows the output
3958 # handle special "x 3 blah" syntax XXX propagate
3959 # doc back to special variables.
3960 if ( $DB::cmd =~ s#\A\s*(\d+)(?=\s)# #) {
3961 $onetimedumpDepth = $1;
3968 sub _handle_q_command {
3971 if ($self->_is_full('q')) {
3980 sub _handle_cmd_wrapper_commands {
3983 DB::cmd_wrapper( $self->cmd_verb, $self->cmd_args, $line );
3987 sub _handle_special_char_cmd_wrapper_commands {
3990 # All of these commands were remapped in perl 5.8.0;
3991 # we send them off to the secondary dispatcher (see below).
3992 if (my ($cmd_letter, $my_arg) = $DB::cmd =~ /\A([<>\{]{1,2})\s*(.*)/so) {
3993 DB::cmd_wrapper( $cmd_letter, $my_arg, $line );
4004 # The following code may be executed now:
4009 C<sub> is called whenever a subroutine call happens in the program being
4010 debugged. The variable C<$DB::sub> contains the name of the subroutine
4013 The core function of this subroutine is to actually call the sub in the proper
4014 context, capturing its output. This of course causes C<DB::DB> to get called
4015 again, repeating until the subroutine ends and returns control to C<DB::sub>
4016 again. Once control returns, C<DB::sub> figures out whether or not to dump the
4017 return value, and returns its captured copy of the return value as its own
4018 return value. The value then feeds back into the program being debugged as if
4019 C<DB::sub> hadn't been there at all.
4021 C<sub> does all the work of printing the subroutine entry and exit messages
4022 enabled by setting C<$frame>. It notes what sub the autoloader got called for,
4023 and also prints the return value if needed (for the C<r> command and if
4024 the 16 bit is set in C<$frame>).
4026 It also tracks the subroutine call depth by saving the current setting of
4027 C<$single> in the C<@stack> package global; if this exceeds the value in
4028 C<$deep>, C<sub> automatically turns on printing of the current depth by
4029 setting the C<4> bit in C<$single>. In any case, it keeps the current setting
4030 of stop/don't stop on entry to subs set as it currently is set.
4032 =head3 C<caller()> support
4034 If C<caller()> is called from the package C<DB>, it provides some
4035 additional data, in the following order:
4041 The package name the sub was in
4043 =item * C<$filename>
4045 The filename it was defined in
4049 The line number it was defined on
4051 =item * C<$subroutine>
4053 The subroutine name; C<(eval)> if an C<eval>().
4057 1 if it has arguments, 0 if not
4059 =item * C<$wantarray>
4061 1 if array context, 0 if scalar context
4063 =item * C<$evaltext>
4065 The C<eval>() text, if any (undefined for C<eval BLOCK>)
4067 =item * C<$is_require>
4069 frame was created by a C<use> or C<require> statement
4073 pragma information; subject to change between versions
4077 pragma information; subject to change between versions
4079 =item * C<@DB::args>
4081 arguments with which the subroutine was invoked
4089 # We need to fully qualify the name ("DB::sub") to make "use strict;"
4090 # happy. -- Shlomi Fish
4092 sub _indent_print_line_info {
4093 my ($offset, $str) = @_;
4095 print_lineinfo( ' ' x ($stack_depth - $offset), $str);
4100 sub _print_frame_message {
4104 if ($frame & 4) { # Extended frame entry message
4105 _indent_print_line_info(-1, "in ");
4107 # Why -1? But it works! :-(
4108 # Because print_trace will call add 1 to it and then call
4109 # dump_trace; this results in our skipping -1+1 = 0 stack frames
4112 # Now it's 0 because we extracted a function.
4113 print_trace( $LINEINFO, 0, 1, 1, "$sub$al" );
4116 _indent_print_line_info(-1, "entering $sub$al\n" );
4124 # lock ourselves under threads
4127 # Whether or not the autoloader was running, a scalar to put the
4128 # sub's return value in (if needed), and an array to put the sub's
4129 # return value in (if needed).
4130 my ( $al, $ret, @ret ) = "";
4131 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) {
4132 print "creating new thread\n";
4135 # If the last ten characters are '::AUTOLOAD', note we've traced
4136 # into AUTOLOAD for $sub.
4137 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
4139 $al = " for $$sub" if defined $$sub;
4142 # We stack the stack pointer and then increment it to protect us
4143 # from a situation that might unwind a whole bunch of call frames
4144 # at once. Localizing the stack pointer means that it will automatically
4145 # unwind the same amount when multiple stack frames are unwound.
4146 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
4149 $#stack = $stack_depth;
4151 # Save current single-step setting.
4152 $stack[-1] = $single;
4154 # Turn off all flags except single-stepping.
4157 # If we've gotten really deeply recursed, turn on the flag that will
4158 # make us stop with the 'deep recursion' message.
4159 $single |= 4 if $stack_depth == $deep;
4161 # If frame messages are on ...
4163 _print_frame_message($al);
4164 # standard frame entry message
4166 my $print_exit_msg = sub {
4167 # Check for exit trace messages...
4170 if ($frame & 4) # Extended exit message
4172 _indent_print_line_info(0, "out ");
4173 print_trace( $LINEINFO, 0, 1, 1, "$sub$al" );
4177 _indent_print_line_info(0, "exited $sub$al\n" );
4183 # Determine the sub's return type, and capture appropriately.
4186 # Called in array context. call sub and capture output.
4187 # DB::DB will recursively get control again if appropriate; we'll come
4188 # back here when the sub is finished.
4194 # Pop the single-step value back off the stack.
4195 $single |= $stack[ $stack_depth-- ];
4197 $print_exit_msg->();
4199 # Print the return info if we need to.
4200 if ( $doret eq $stack_depth or $frame & 16 ) {
4202 # Turn off output record separator.
4204 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4206 # Indent if we're printing because of $frame tracing.
4209 print {$fh} ' ' x $stack_depth;
4212 # Print the return value.
4213 print {$fh} "list context return from $sub:\n";
4214 dumpit( $fh, \@ret );
4216 # And don't print it again.
4218 } ## end if ($doret eq $stack_depth...
4219 # And we have to return the return value now.
4221 } ## end if (wantarray)
4225 if ( defined wantarray ) {
4227 # Save the value if it's wanted at all.
4232 # Void return, explicitly.
4237 # Pop the single-step value off the stack.
4238 $single |= $stack[ $stack_depth-- ];
4240 # If we're doing exit messages...
4241 $print_exit_msg->();
4243 # If we are supposed to show the return value... same as before.
4244 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) {
4246 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
4247 print $fh ( ' ' x $stack_depth ) if $frame & 16;
4250 ? "scalar context return from $sub: "
4251 : "void context return from $sub\n"
4253 dumpit( $fh, $ret ) if defined wantarray;
4255 } ## end if ($doret eq $stack_depth...
4257 # Return the appropriate scalar value.
4259 } ## end else [ if (wantarray)
4266 # lock ourselves under threads
4269 # Whether or not the autoloader was running, a scalar to put the
4270 # sub's return value in (if needed), and an array to put the sub's
4271 # return value in (if needed).
4272 my ( $al, $ret, @ret ) = "";
4273 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
4274 print "creating new thread\n";
4277 # If the last ten characters are C'::AUTOLOAD', note we've traced
4278 # into AUTOLOAD for $sub.
4279 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
4283 # We stack the stack pointer and then increment it to protect us
4284 # from a situation that might unwind a whole bunch of call frames
4285 # at once. Localizing the stack pointer means that it will automatically
4286 # unwind the same amount when multiple stack frames are unwound.
4287 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
4290 $#stack = $stack_depth;
4292 # Save current single-step setting.
4293 $stack[-1] = $single;
4295 # Turn off all flags except single-stepping.
4296 # Use local so the single-step value is popped back off the
4298 local $single = $single & 1;
4300 # If we've gotten really deeply recursed, turn on the flag that will
4301 # make us stop with the 'deep recursion' message.
4302 $single |= 4 if $stack_depth == $deep;
4304 # If frame messages are on ...
4305 _print_frame_message($al);
4307 # call the original lvalue sub.
4311 # Abstracting common code from multiple places elsewhere:
4312 sub depth_print_lineinfo {
4313 my $always_print = shift;
4315 print_lineinfo( @_ ) if ($always_print or $stack_depth < $trace_to_depth);
4318 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API
4320 In Perl 5.8.0, there was a major realignment of the commands and what they did,
4321 Most of the changes were to systematize the command structure and to eliminate
4322 commands that threw away user input without checking.
4324 The following sections describe the code added to make it easy to support
4325 multiple command sets with conflicting command names. This section is a start
4326 at unifying all command processing to make it simpler to develop commands.
4328 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line
4329 number, and C<$dbline> (the current line) as arguments.
4331 Support functions in this section which have multiple modes of failure C<die>
4332 on error; the rest simply return a false value.
4334 The user-interface functions (all of the C<cmd_*> functions) just output
4339 The C<%set> hash defines the mapping from command letter to subroutine
4342 C<%set> is a two-level hash, indexed by set name and then by command name.
4343 Note that trying to set the CommandSet to C<foobar> simply results in the
4344 5.8.0 command set being used, since there's no top-level entry for C<foobar>.
4353 'A' => 'pre580_null',
4355 'B' => 'pre580_null',
4356 'd' => 'pre580_null',
4359 'M' => 'pre580_null',
4361 'o' => 'pre580_null',
4367 '<' => 'pre590_prepost',
4368 '<<' => 'pre590_prepost',
4369 '>' => 'pre590_prepost',
4370 '>>' => 'pre590_prepost',
4371 '{' => 'pre590_prepost',
4372 '{{' => 'pre590_prepost',
4376 my %breakpoints_data;
4378 sub _has_breakpoint_data_ref {
4379 my ($filename, $line) = @_;
4382 exists( $breakpoints_data{$filename} )
4384 exists( $breakpoints_data{$filename}{$line} )
4388 sub _get_breakpoint_data_ref {
4389 my ($filename, $line) = @_;
4391 return ($breakpoints_data{$filename}{$line} ||= +{});
4394 sub _delete_breakpoint_data_ref {
4395 my ($filename, $line) = @_;
4397 delete($breakpoints_data{$filename}{$line});
4398 if (! scalar(keys( %{$breakpoints_data{$filename}} )) ) {
4399 delete($breakpoints_data{$filename});
4405 sub _set_breakpoint_enabled_status {
4406 my ($filename, $line, $status) = @_;
4408 _get_breakpoint_data_ref($filename, $line)->{'enabled'} =
4415 sub _enable_breakpoint_temp_enabled_status {
4416 my ($filename, $line) = @_;
4418 _get_breakpoint_data_ref($filename, $line)->{'temp_enabled'} = 1;
4423 sub _cancel_breakpoint_temp_enabled_status {
4424 my ($filename, $line) = @_;
4426 my $ref = _get_breakpoint_data_ref($filename, $line);
4428 delete ($ref->{'temp_enabled'});
4431 _delete_breakpoint_data_ref($filename, $line);
4437 sub _is_breakpoint_enabled {
4438 my ($filename, $line) = @_;
4440 my $data_ref = _get_breakpoint_data_ref($filename, $line);
4441 return ($data_ref->{'enabled'} || $data_ref->{'temp_enabled'});
4444 =head2 C<cmd_wrapper()> (API)
4446 C<cmd_wrapper()> allows the debugger to switch command sets
4447 depending on the value of the C<CommandSet> option.
4449 It tries to look up the command in the C<%set> package-level I<lexical>
4450 (which means external entities can't fiddle with it) and create the name of
4451 the sub to call based on the value found in the hash (if it's there). I<All>
4452 of the commands to be handled in a set have to be added to C<%set>; if they
4453 aren't found, the 5.8.0 equivalent is called (if there is one).
4455 This code uses symbolic references.
4462 my $dblineno = shift;
4464 # Assemble the command subroutine's name by looking up the
4465 # command set and command name in %set. If we can't find it,
4466 # default to the older version of the command.
4468 . ( $set{$CommandSet}{$cmd}
4469 || ( $cmd =~ /\A[<>{]+/o ? 'prepost' : $cmd ) );
4471 # Call the command subroutine, call it by name.
4472 return __PACKAGE__->can($call)->( $cmd, $line, $dblineno );
4473 } ## end sub cmd_wrapper
4475 =head3 C<cmd_a> (command)
4477 The C<a> command handles pre-execution actions. These are associated with a
4478 particular line, so they're stored in C<%dbline>. We default to the current
4479 line if none is specified.
4485 my $line = shift || ''; # [.|line] expr
4488 # If it's dot (here), or not all digits, use the current line.
4489 $line =~ s/\A\./$dbline/;
4491 # Should be a line number followed by an expression.
4492 if ( my ($lineno, $expr) = $line =~ /^\s*(\d*)\s*(\S.+)/ ) {
4494 if (! length($lineno)) {
4498 # If we have an expression ...
4499 if ( length $expr ) {
4501 # ... but the line isn't breakable, complain.
4502 if ( $dbline[$lineno] == 0 ) {
4504 "Line $lineno($dbline[$lineno]) does not have an action?\n";
4508 # It's executable. Record that the line has an action.
4509 $had_breakpoints{$filename} |= 2;
4511 # Remove any action, temp breakpoint, etc.
4512 $dbline{$lineno} =~ s/\0[^\0]*//;
4514 # Add the action to the line.
4515 $dbline{$lineno} .= "\0" . action($expr);
4517 _set_breakpoint_enabled_status($filename, $lineno, 1);
4519 } ## end if (length $expr)
4520 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/)
4525 "Adding an action requires an optional lineno and an expression\n"
4530 =head3 C<cmd_A> (command)
4532 Delete actions. Similar to above, except the delete code is in a separate
4533 subroutine, C<delete_action>.
4539 my $line = shift || '';
4543 $line =~ s/^\./$dbline/;
4545 # Call delete_action with a null param to delete them all.
4546 # The '1' forces the eval to be true. It'll be false only
4547 # if delete_action blows up for some reason, in which case
4548 # we print $@ and get out.
4549 if ( $line eq '*' ) {
4550 if (! eval { _delete_all_actions(); 1 }) {
4556 # There's a real line number. Pass it to delete_action.
4557 # Error trapping is as above.
4558 elsif ( $line =~ /^(\S.*)/ ) {
4559 if (! eval { delete_action($1); 1 }) {
4565 # Swing and a miss. Bad syntax.
4568 "Deleting an action requires a line number, or '*' for all\n" ; # hint
4572 =head3 C<delete_action> (API)
4574 C<delete_action> accepts either a line number or C<undef>. If a line number
4575 is specified, we check for the line being executable (if it's not, it
4576 couldn't have had an action). If it is, we just take the action off (this
4577 will get any kind of an action, including breakpoints).
4581 sub _remove_action_from_dbline {
4584 $dbline{$i} =~ s/\0[^\0]*//; # \^a
4585 delete $dbline{$i} if $dbline{$i} eq '';
4590 sub _delete_all_actions {
4591 print {$OUT} "Deleting all actions...\n";
4593 for my $file ( keys %had_breakpoints ) {
4594 local *dbline = $main::{ '_<' . $file };
4597 for my $i (1 .. $max) {
4598 if ( defined $dbline{$i} ) {
4599 _remove_action_from_dbline($i);
4603 unless ( $had_breakpoints{$file} &= ~2 ) {
4604 delete $had_breakpoints{$file};
4614 if ( defined($i) ) {
4616 die "Line $i has no action .\n" if $dbline[$i] == 0;
4618 # Nuke whatever's there.
4619 _remove_action_from_dbline($i);
4622 _delete_all_actions();
4626 =head3 C<cmd_b> (command)
4628 Set breakpoints. Since breakpoints can be set in so many places, in so many
4629 ways, conditionally or not, the breakpoint code is kind of complex. Mostly,
4630 we try to parse the command type, and then shuttle it off to an appropriate
4631 subroutine to actually do the work of setting the breakpoint in the right
4638 my $line = shift; # [.|line] [cond]
4641 my $default_cond = sub {
4643 return length($cond) ? $cond : '1';
4646 # Make . the current line number if it's there..
4647 $line =~ s/^\.(\s|\z)/$dbline$1/;
4649 # No line number, no condition. Simple break on current line.
4650 if ( $line =~ /^\s*$/ ) {
4651 cmd_b_line( $dbline, 1 );
4654 # Break on load for a file.
4655 elsif ( my ($file) = $line =~ /^load\b\s*(.*)/ ) {
4660 # b compile|postpone <some sub> [<condition>]
4661 # The interpreter actually traps this one for us; we just put the
4662 # necessary condition in the %postponed hash.
4663 elsif ( my ($action, $subname, $cond)
4664 = $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
4666 # De-Perl4-ify the name - ' separators to ::.
4667 $subname =~ s/'/::/g;
4669 # Qualify it into the current package unless it's already qualified.
4670 $subname = "${package}::" . $subname unless $subname =~ /::/;
4672 # Add main if it starts with ::.
4673 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
4675 # Save the break type for this sub.
4676 $postponed{$subname} = (($action eq 'postpone')
4677 ? ( "break +0 if " . $default_cond->($cond) )
4679 } ## end elsif ($line =~ ...
4680 # b <filename>:<line> [<condition>]
4681 elsif (my ($filename, $line_num, $cond)
4682 = $line =~ /\A(\S+[^:]):(\d+)\s*(.*)/ms) {
4683 cmd_b_filename_line(
4686 (length($cond) ? $cond : '1'),
4689 # b <sub name> [<condition>]
4690 elsif ( my ($new_subname, $new_cond) =
4691 $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
4694 $subname = $new_subname;
4695 cmd_b_sub( $subname, $default_cond->($new_cond) );
4698 # b <line> [<condition>].
4699 elsif ( my ($line_n, $cond) = $line =~ /^(\d*)\s*(.*)/ ) {
4701 # Capture the line. If none, it's the current line.
4702 $line = $line_n || $dbline;
4705 cmd_b_line( $line, $default_cond->($cond) );
4708 # Line didn't make sense.
4710 print "confused by line($line)?\n";
4716 =head3 C<break_on_load> (API)
4718 We want to break when this file is loaded. Mark this file in the
4719 C<%break_on_load> hash, and note that it has a breakpoint in
4720 C<%had_breakpoints>.
4726 $break_on_load{$file} = 1;
4727 $had_breakpoints{$file} |= 1;
4730 =head3 C<report_break_on_load> (API)
4732 Gives us an array of filenames that are set to break on load. Note that
4733 only files with break-on-load are in here, so simply showing the keys
4738 sub report_break_on_load {
4739 sort keys %break_on_load;
4742 =head3 C<cmd_b_load> (command)
4744 We take the file passed in and try to find it in C<%INC> (which maps modules
4745 to files they came from). We mark those files for break-on-load via
4746 C<break_on_load> and then report that it was done.
4754 # This is a block because that way we can use a redo inside it
4755 # even without there being any looping structure at all outside it.
4758 # Save short name and full path if found.
4760 push @files, $::INC{$file} if $::INC{$file};
4762 # Tack on .pm and do it again unless there was a '.' in the name
4764 $file .= '.pm', redo unless $file =~ /\./;
4767 # Do the real work here.
4768 break_on_load($_) for @files;
4770 # All the files that have break-on-load breakpoints.
4771 @files = report_break_on_load;
4773 # Normalize for the purposes of our printing this.
4776 print $OUT "Will stop on load of '@files'.\n";
4777 } ## end sub cmd_b_load
4779 =head3 C<$filename_error> (API package global)
4781 Several of the functions we need to implement in the API need to work both
4782 on the current file and on other files. We don't want to duplicate code, so
4783 C<$filename_error> is used to contain the name of the file that's being
4784 worked on (if it's not the current one).
4786 We can now build functions in pairs: the basic function works on the current
4787 file, and uses C<$filename_error> as part of its error message. Since this is
4788 initialized to C<"">, no filename will appear when we are working on the
4791 The second function is a wrapper which does the following:
4797 Localizes C<$filename_error> and sets it to the name of the file to be processed.
4801 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process.
4805 Calls the first function.
4807 The first function works on the I<current> file (i.e., the one we changed to),
4808 and prints C<$filename_error> in the error message (the name of the other file)
4809 if it needs to. When the functions return, C<*dbline> is restored to point
4810 to the actual current file (the one we're executing in) and
4811 C<$filename_error> is restored to C<"">. This restores everything to
4812 the way it was before the second function was called at all.
4814 See the comments in C<breakable_line> and C<breakable_line_in_file> for more
4821 use vars qw($filename_error);
4822 $filename_error = '';
4824 =head3 breakable_line(from, to) (API)
4826 The subroutine decides whether or not a line in the current file is breakable.
4827 It walks through C<@dbline> within the range of lines specified, looking for
4828 the first line that is breakable.
4830 If C<$to> is greater than C<$from>, the search moves forwards, finding the
4831 first line I<after> C<$to> that's breakable, if there is one.
4833 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the
4834 first line I<before> C<$to> that's breakable, if there is one.
4838 sub breakable_line {
4840 my ( $from, $to ) = @_;
4842 # $i is the start point. (Where are the FORTRAN programs of yesteryear?)
4845 # If there are at least 2 arguments, we're trying to search a range.
4848 # $delta is positive for a forward search, negative for a backward one.
4849 my $delta = $from < $to ? +1 : -1;
4851 # Keep us from running off the ends of the file.
4852 my $limit = $delta > 0 ? $#dbline : 1;
4854 # Clever test. If you're a mathematician, it's obvious why this
4855 # test works. If not:
4856 # If $delta is positive (going forward), $limit will be $#dbline.
4857 # If $to is less than $limit, ($limit - $to) will be positive, times
4858 # $delta of 1 (positive), so the result is > 0 and we should use $to
4859 # as the stopping point.
4861 # If $to is greater than $limit, ($limit - $to) is negative,
4862 # times $delta of 1 (positive), so the result is < 0 and we should
4863 # use $limit ($#dbline) as the stopping point.
4865 # If $delta is negative (going backward), $limit will be 1.
4866 # If $to is zero, ($limit - $to) will be 1, times $delta of -1
4867 # (negative) so the result is > 0, and we use $to as the stopping
4870 # If $to is less than zero, ($limit - $to) will be positive,
4871 # times $delta of -1 (negative), so the result is not > 0, and
4872 # we use $limit (1) as the stopping point.
4874 # If $to is 1, ($limit - $to) will zero, times $delta of -1
4875 # (negative), still giving zero; the result is not > 0, and
4876 # we use $limit (1) as the stopping point.
4878 # if $to is >1, ($limit - $to) will be negative, times $delta of -1
4879 # (negative), giving a positive (>0) value, so we'll set $limit to
4882 $limit = $to if ( $limit - $to ) * $delta > 0;
4884 # The real search loop.
4885 # $i starts at $from (the point we want to start searching from).
4886 # We move through @dbline in the appropriate direction (determined
4887 # by $delta: either -1 (back) or +1 (ahead).
4888 # We stay in as long as we haven't hit an executable line
4889 # ($dbline[$i] == 0 means not executable) and we haven't reached
4890 # the limit yet (test similar to the above).
4891 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0;
4893 } ## end if (@_ >= 2)
4895 # If $i points to a line that is executable, return that.
4896 return $i unless $dbline[$i] == 0;
4898 # Format the message and print it: no breakable lines in range.
4899 my ( $pl, $upto ) = ( '', '' );
4900 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to;
4902 # If there's a filename in filename_error, we'll see it.
4904 die "Line$pl $from$upto$filename_error not breakable\n";
4905 } ## end sub breakable_line
4907 =head3 breakable_line_in_filename(file, from, to) (API)
4909 Like C<breakable_line>, but look in another file.
4913 sub breakable_line_in_filename {
4915 # Capture the file name.
4918 # Swap the magic line array over there temporarily.
4919 local *dbline = $main::{ '_<' . $f };
4921 # If there's an error, it's in this other file.
4922 local $filename_error = " of '$f'";
4924 # Find the breakable line.
4927 # *dbline and $filename_error get restored when this block ends.
4929 } ## end sub breakable_line_in_filename
4931 =head3 break_on_line(lineno, [condition]) (API)
4933 Adds a breakpoint with the specified condition (or 1 if no condition was
4934 specified) to the specified line. Dies if it can't.
4940 my $cond = @_ ? shift(@_) : 1;
4946 # Woops, not a breakable line. $filename_error allows us to say
4947 # if it was in a different file.
4948 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0;
4950 # Mark this file as having breakpoints in it.
4951 $had_breakpoints{$filename} |= 1;
4953 # If there is an action or condition here already ...
4954 if ( $dbline{$i} ) {
4956 # ... swap this condition for the existing one.
4957 $dbline{$i} =~ s/^[^\0]*/$cond/;
4961 # Nothing here - just add the condition.
4962 $dbline{$i} = $cond;
4964 _set_breakpoint_enabled_status($filename, $i, 1);
4968 } ## end sub break_on_line
4970 =head3 cmd_b_line(line, [condition]) (command)
4972 Wrapper for C<break_on_line>. Prints the failure message if it
4978 if (not eval { break_on_line(@_); 1 }) {
4980 print $OUT $@ and return;
4984 } ## end sub cmd_b_line
4986 =head3 cmd_b_filename_line(line, [condition]) (command)
4988 Wrapper for C<break_on_filename_line>. Prints the failure message if it
4993 sub cmd_b_filename_line {
4994 if (not eval { break_on_filename_line(@_); 1 }) {
4996 print $OUT $@ and return;
5002 =head3 break_on_filename_line(file, line, [condition]) (API)
5004 Switches to the file specified and then calls C<break_on_line> to set
5009 sub break_on_filename_line {
5012 my $cond = @_ ? shift(@_) : 1;
5014 # Switch the magical hash temporarily.
5015 local *dbline = $main::{ '_<' . $f };
5017 # Localize the variables that break_on_line uses to make its message.
5018 local $filename_error = " of '$f'";
5019 local $filename = $f;
5021 # Add the breakpoint.
5022 break_on_line( $i, $cond );
5025 } ## end sub break_on_filename_line
5027 =head3 break_on_filename_line_range(file, from, to, [condition]) (API)
5029 Switch to another file, search the range of lines specified for an
5030 executable one, and put a breakpoint on the first one you find.
5034 sub break_on_filename_line_range {
5038 my $cond = @_ ? shift(@_) : 1;
5040 # Find a breakable line if there is one.
5041 my $i = breakable_line_in_filename( $f, $from, $to );
5043 # Add the breakpoint.
5044 break_on_filename_line( $f, $i, $cond );
5047 } ## end sub break_on_filename_line_range
5049 =head3 subroutine_filename_lines(subname, [condition]) (API)
5051 Search for a subroutine within a given file. The condition is ignored.
5052 Uses C<find_sub> to locate the desired subroutine.
5056 sub subroutine_filename_lines {
5057 my ( $subname ) = @_;
5059 # Returned value from find_sub() is fullpathname:startline-endline.
5060 # The match creates the list (fullpathname, start, end).
5061 return (find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/);
5062 } ## end sub subroutine_filename_lines
5064 =head3 break_subroutine(subname) (API)
5066 Places a break on the first line possible in the specified subroutine. Uses
5067 C<subroutine_filename_lines> to find the subroutine, and
5068 C<break_on_filename_line_range> to place the break.
5072 sub break_subroutine {
5073 my $subname = shift;
5075 # Get filename, start, and end.
5076 my ( $file, $s, $e ) = subroutine_filename_lines($subname)
5077 or die "Subroutine $subname not found.\n";
5080 # Null condition changes to '1' (always true).
5081 my $cond = @_ ? shift(@_) : 1;
5083 # Put a break the first place possible in the range of lines
5084 # that make up this subroutine.
5085 break_on_filename_line_range( $file, $s, $e, $cond );
5088 } ## end sub break_subroutine
5090 =head3 cmd_b_sub(subname, [condition]) (command)
5092 We take the incoming subroutine name and fully-qualify it as best we can.
5096 =item 1. If it's already fully-qualified, leave it alone.
5098 =item 2. Try putting it in the current package.
5100 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there.
5102 =item 4. If it starts with '::', put it in 'main::'.
5106 After all this cleanup, we call C<break_subroutine> to try to set the
5112 my $subname = shift;
5113 my $cond = @_ ? shift : 1;
5115 # If the subname isn't a code reference, qualify it so that
5116 # break_subroutine() will work right.
5117 if ( ref($subname) ne 'CODE' ) {
5120 $subname =~ s/'/::/g;
5123 # Put it in this package unless it's already qualified.
5124 if ($subname !~ /::/)
5126 $subname = $package . '::' . $subname;
5129 # Requalify it into CORE::GLOBAL if qualifying it into this
5130 # package resulted in its not being defined, but only do so
5131 # if it really is in CORE::GLOBAL.
5132 my $core_name = "CORE::GLOBAL::$s";
5133 if ((!defined(&$subname))
5135 and (defined &{$core_name}))
5137 $subname = $core_name;
5140 # Put it in package 'main' if it has a leading ::.
5141 if ($subname =~ /\A::/)
5143 $subname = "main" . $subname;
5145 } ## end if ( ref($subname) ne 'CODE' ) {
5147 # Try to set the breakpoint.
5148 if (not eval { break_subroutine( $subname, $cond ); 1 }) {
5155 } ## end sub cmd_b_sub
5157 =head3 C<cmd_B> - delete breakpoint(s) (command)
5159 The command mostly parses the command line and tries to turn the argument
5160 into a line spec. If it can't, it uses the current line. It then calls
5161 C<delete_breakpoint> to actually do the work.
5163 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments,
5164 thereby deleting all the breakpoints.
5171 # No line spec? Use dbline.
5172 # If there is one, use it if it's non-zero, or wipe it out if it is.
5173 my $line = ( $_[0] =~ /\A\./ ) ? $dbline : (shift || '');
5176 # If the line was dot, make the line the current one.
5177 $line =~ s/^\./$dbline/;
5179 # If it's * we're deleting all the breakpoints.
5180 if ( $line eq '*' ) {
5181 if (not eval { delete_breakpoint(); 1 }) {
5186 # If there is a line spec, delete the breakpoint on that line.
5187 elsif ( $line =~ /\A(\S.*)/ ) {
5188 if (not eval { delete_breakpoint( $line || $dbline ); 1 }) {
5192 } ## end elsif ($line =~ /^(\S.*)/)
5197 "Deleting a breakpoint requires a line number, or '*' for all\n"
5204 =head3 delete_breakpoint([line]) (API)
5206 This actually does the work of deleting either a single breakpoint, or all
5209 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we
5210 just drop out with a message saying so. If it is, we remove the condition
5211 part of the 'condition\0action' that says there's a breakpoint here. If,
5212 after we've done that, there's nothing left, we delete the corresponding
5213 line in C<%dbline> to signal that no action needs to be taken for this line.
5215 For all breakpoints, we iterate through the keys of C<%had_breakpoints>,
5216 which lists all currently-loaded files which have breakpoints. We then look
5217 at each line in each of these files, temporarily switching the C<%dbline>
5218 and C<@dbline> structures to point to the files in question, and do what
5219 we did in the single line case: delete the condition in C<@dbline>, and
5220 delete the key in C<%dbline> if nothing's left.
5222 We then wholesale delete C<%postponed>, C<%postponed_file>, and
5223 C<%break_on_load>, because these structures contain breakpoints for files
5224 and code that haven't been loaded yet. We can just kill these off because there
5225 are no magical debugger structures associated with them.
5229 sub _remove_breakpoint_entry {
5233 _delete_breakpoint_data_ref($fn, $i);
5238 sub _delete_all_breakpoints {
5239 print {$OUT} "Deleting all breakpoints...\n";
5241 # %had_breakpoints lists every file that had at least one
5243 for my $fn ( keys %had_breakpoints ) {
5245 # Switch to the desired file temporarily.
5246 local *dbline = $main::{ '_<' . $fn };
5250 # For all lines in this file ...
5251 for my $i (1 .. $max) {
5253 # If there's a breakpoint or action on this line ...
5254 if ( defined $dbline{$i} ) {
5256 # ... remove the breakpoint.
5257 $dbline{$i} =~ s/\A[^\0]+//;
5258 if ( $dbline{$i} =~ s/\A\0?\z// ) {
5259 # Remove the entry altogether if no action is there.
5260 _remove_breakpoint_entry($fn, $i);
5262 } ## end if (defined $dbline{$i...
5263 } ## end for $i (1 .. $max)
5265 # If, after we turn off the "there were breakpoints in this file"
5266 # bit, the entry in %had_breakpoints for this file is zero,
5267 # we should remove this file from the hash.
5268 if ( not $had_breakpoints{$fn} &= (~1) ) {
5269 delete $had_breakpoints{$fn};
5271 } ## end for my $fn (keys %had_breakpoints)
5273 # Kill off all the other breakpoints that are waiting for files that
5274 # haven't been loaded yet.
5276 undef %postponed_file;
5277 undef %break_on_load;
5282 sub _delete_breakpoint_from_line {
5285 # Woops. This line wasn't breakable at all.
5286 die "Line $i not breakable.\n" if $dbline[$i] == 0;
5288 # Kill the condition, but leave any action.
5289 $dbline{$i} =~ s/\A[^\0]*//;
5291 # Remove the entry entirely if there's no action left.
5292 if ($dbline{$i} eq '') {
5293 _remove_breakpoint_entry($filename, $i);
5299 sub delete_breakpoint {
5302 # If we got a line, delete just that one.
5303 if ( defined($i) ) {
5304 _delete_breakpoint_from_line($i);
5306 # No line; delete them all.
5308 _delete_all_breakpoints();
5314 =head3 cmd_stop (command)
5316 This is meant to be part of the new command API, but it isn't called or used
5317 anywhere else in the debugger. XXX It is probably meant for use in development
5322 sub cmd_stop { # As on ^C, but not signal-safy.
5326 =head3 C<cmd_e> - threads
5328 Display the current thread id:
5332 This could be how (when implemented) to send commands to this thread id (e cmd)
5333 or that thread id (e tid cmd).
5340 unless (exists($INC{'threads.pm'})) {
5341 print "threads not loaded($ENV{PERL5DB_THREADED})
5342 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5344 my $tid = threads->tid;
5345 print "thread id: $tid\n";
5349 =head3 C<cmd_E> - list of thread ids
5351 Display the list of available thread ids:
5355 This could be used (when implemented) to send commands to all threads (E cmd).
5362 unless (exists($INC{'threads.pm'})) {
5363 print "threads not loaded($ENV{PERL5DB_THREADED})
5364 please run the debugger with PERL5DB_THREADED=1 set in the environment\n";
5366 my $tid = threads->tid;
5367 print "thread ids: ".join(', ',
5368 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list
5373 =head3 C<cmd_h> - help command (command)
5375 Does the work of either
5381 Showing all the debugger help
5385 Showing help for a specific command
5392 use vars qw($summary);
5397 # If we have no operand, assume null.
5398 my $line = shift || '';
5400 # 'h h'. Print the long-format help.
5401 if ( $line =~ /\Ah\s*\z/ ) {
5405 # 'h <something>'. Search for the command and print only its help.
5406 elsif ( my ($asked) = $line =~ /\A(\S.*)\z/ ) {
5408 # support long commands; otherwise bogus errors
5409 # happen when you ask for h on <CR> for example
5410 my $qasked = quotemeta($asked); # for searching; we don't
5411 # want to use it as a pattern.
5412 # XXX: finds CR but not <CR>
5414 # Search the help string for the command.
5416 $help =~ /^ # Start of a line
5418 (?:[IB]<) # Optional markup
5419 $qasked # The requested command
5424 # It's there; pull it out and print it.
5428 (?:[IB]<) # Optional markup
5429 $qasked # The command
5430 ([\s\S]*?) # Description line(s)
5431 \n) # End of last description line
5432 (?!\s) # Next line not starting with
5441 # Not found; not a debugger command.
5443 print_help("B<$asked> is not a debugger command.\n");
5445 } ## end elsif ($line =~ /^(\S.*)$/)
5447 # 'h' - print the summary help.
5449 print_help($summary);
5453 =head3 C<cmd_i> - inheritance display
5455 Display the (nested) parentage of the module or object given.
5462 foreach my $isa ( split( /\s+/, $line ) ) {
5464 # The &-call is here to ascertain the mutability of @_.
5472 defined( ${"$_\::VERSION"} )
5473 ? ' ' . ${"$_\::VERSION"}
5475 } @{mro::get_linear_isa(ref($isa) || $isa)}
5481 =head3 C<cmd_l> - list lines (command)
5483 Most of the command is taken up with transforming all the different line
5484 specification syntaxes into 'start-stop'. After that is done, the command
5485 runs a loop over C<@dbline> for the specified range of lines. It handles
5486 the printing of each line and any markers (C<==E<gt>> for current line,
5487 C<b> for break on this line, C<a> for action on this line, C<:> for this
5490 We save the last line listed in the C<$start> global for further listing
5497 foreach my $v (@_) {
5507 foreach my $v (@_) {
5515 sub _minify_to_max {
5518 $$ref = _min($$ref, $max);
5523 sub _cmd_l_handle_var_name {
5524 my $var_name = shift;
5526 $evalarg = $var_name;
5528 my ($s) = DB::eval();
5530 # Ooops. Bad scalar.
5532 print {$OUT} "Error: $@\n";
5536 # Good scalar. If it's a reference, find what it points to.
5538 print {$OUT} "Interpreted as: $1 $s\n";
5541 # Call self recursively to really do the command.
5542 return _cmd_l_main( $s );
5545 sub _cmd_l_handle_subname {
5550 $subname =~ s/\'/::/;
5552 # Put it in this package unless it starts with ::.
5553 $subname = $package . "::" . $subname unless $subname =~ /::/;
5555 # Put it in CORE::GLOBAL if t doesn't start with :: and
5556 # it doesn't live in this package and it lives in CORE::GLOBAL.
5557 $subname = "CORE::GLOBAL::$s"
5558 if not defined &$subname
5560 and defined &{"CORE::GLOBAL::$s"};
5562 # Put leading '::' names into 'main::'.
5563 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
5565 # Get name:start-stop from find_sub, and break this up at
5567 my @pieces = split( /:/, find_sub($subname) || $sub{$subname} );
5569 # Pull off start-stop.
5570 my $subrange = pop @pieces;
5572 # If the name contained colons, the split broke it up.
5573 # Put it back together.
5574 $file = join( ':', @pieces );
5576 # If we're not in that file, switch over to it.
5577 if ( $file ne $filename ) {
5578 if (! $slave_editor) {
5579 print {$OUT} "Switching to file '$file'.\n";
5582 # Switch debugger's magic structures.
5583 *dbline = $main::{ '_<' . $file };
5586 } ## end if ($file ne $filename)
5588 # Subrange is 'start-stop'. If this is less than a window full,
5589 # swap it to 'start+', which will list a window from the start point.
5591 if ( eval($subrange) < -$window ) {
5592 $subrange =~ s/-.*/+/;
5595 # Call self recursively to list the range.
5596 return _cmd_l_main( $subrange );
5597 } ## end if ($subrange)
5601 print {$OUT} "Subroutine $subname not found.\n";
5607 # Compute new range to list.
5608 $incr = $window - 1;
5611 return _cmd_l_main( $start . '-' . ( $start + $incr ) );
5615 my ($new_start, $new_incr) = @_;
5617 # Don't reset start for 'l +nnn'.
5618 $start = $new_start if $new_start;
5620 # Increment for list. Use window size if not specified.
5621 # (Allows 'l +' to work.)
5622 $incr = $new_incr || ($window - 1);
5624 # Create a line range we'll understand, and recurse to do it.
5625 return _cmd_l_main( $start . '-' . ( $start + $incr ) );
5628 sub _cmd_l_calc_initial_end_and_i {
5629 my ($spec, $start_match, $end_match) = @_;
5631 # Determine end point; use end of file if not specified.
5632 my $end = ( !defined $start_match ) ? $max :
5633 ( $end_match ? $end_match : $start_match );
5635 # Go on to the end, and then stop.
5636 _minify_to_max(\$end);
5638 # Determine start line.
5639 my $i = $start_match;
5653 my ($spec, $current_line, $start_match, $end_match) = @_;
5656 _cmd_l_calc_initial_end_and_i($spec, $start_match, $end_match);
5658 # If we're running under a slave editor, force it to show the lines.
5659 if ($slave_editor) {
5660 print {$OUT} "\032\032$filename:$i:0\n";
5663 # We're doing it ourselves. We want to show the line and special
5665 # - the current line in execution
5666 # - whether a line is breakable or not
5667 # - whether a line has a break or not
5668 # - whether a line has an action or not
5671 for ( ; $i <= $end ; $i++ ) {
5673 # Check for breakpoints and actions.
5674 my ( $stop, $action );
5676 ( $stop, $action ) = split( /\0/, $dbline{$i} );
5679 # ==> if this is the current line in execution,
5680 # : if it's breakable.
5682 ( $i == $current_line and $filename eq $filename_ini )
5684 : ( $dbline[$i] + 0 ? ':' : ' ' );
5686 # Add break and action indicators.
5687 $arrow .= 'b' if $stop;
5688 $arrow .= 'a' if $action;
5691 print {$OUT} "$i$arrow\t", $dbline[$i];
5693 # Move on to the next line. Drop out on an interrupt.
5698 } ## end for (; $i <= $end ; $i++)
5700 # Line the prompt up; print a newline if the last line listed
5701 # didn't have a newline.
5702 if ($dbline[ $i - 1 ] !~ /\n\z/) {
5705 } ## end else [ if ($slave_editor)
5707 # Save the point we last listed to in case another relative 'l'
5708 # command is desired. Don't let it run off the end.
5710 _minify_to_max(\$start);
5718 # If this is '-something', delete any spaces after the dash.
5719 $spec =~ s/\A-\s*\z/-/;
5721 # If the line is '$something', assume this is a scalar containing a
5723 # Set up for DB::eval() - evaluate in *user* context.
5724 if ( my ($var_name) = $spec =~ /\A(\$.*)/s ) {
5725 return _cmd_l_handle_var_name($var_name);
5727 # l name. Try to find a sub by that name.
5728 elsif ( ($subname) = $spec =~ /\A([\':A-Za-z_][\':\w]*(?:\[.*\])?)/s ) {
5729 return _cmd_l_handle_subname();
5732 elsif ( $spec !~ /\S/ ) {
5733 return _cmd_l_empty();
5735 # l [start]+number_of_lines
5736 elsif ( my ($new_start, $new_incr) = $spec =~ /\A(\d*)\+(\d*)\z/ ) {
5737 return _cmd_l_plus($new_start, $new_incr);
5739 # l start-stop or l start,stop
5740 elsif (my ($s, $e) = $spec =~ /^(?:(-?[\d\$\.]+)(?:[-,]([\d\$\.]+))?)?/ ) {
5741 return _cmd_l_range($spec, $line, $s, $e);
5748 my (undef, $line) = @_;
5750 return _cmd_l_main($line);
5753 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command)
5755 To list breakpoints, the command has to look determine where all of them are
5756 first. It starts a C<%had_breakpoints>, which tells us what all files have
5757 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the
5758 magic source and breakpoint data structures) to the file, and then look
5759 through C<%dbline> for lines with breakpoints and/or actions, listing them
5760 out. We look through C<%postponed> not-yet-compiled subroutines that have
5761 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files
5762 that have breakpoints.
5764 Watchpoints are simpler: we just list the entries in C<@to_watch>.
5768 sub _cmd_L_calc_arg {
5769 # If no argument, list everything. Pre-5.8.0 version always lists
5771 my $arg = shift || 'abw';
5772 if ($CommandSet ne '580')
5780 sub _cmd_L_calc_wanted_flags {
5781 my $arg = _cmd_L_calc_arg(shift);
5783 return (map { index($arg, $_) >= 0 ? 1 : 0 } qw(a b w));
5787 sub _cmd_L_handle_breakpoints {
5788 my ($handle_db_line) = @_;
5791 # Look in all the files with breakpoints...
5792 for my $file ( keys %had_breakpoints ) {
5794 # Temporary switch to this file.
5795 local *dbline = $main::{ '_<' . $file };
5797 # Set up to look through the whole file.
5799 my $was; # Flag: did we print something
5802 # For each line in the file ...
5803 for my $i (1 .. $max) {
5805 # We've got something on this line.
5806 if ( defined $dbline{$i} ) {
5808 # Print the header if we haven't.
5810 print {$OUT} "$file:\n";
5814 print {$OUT} " $i:\t", $dbline[$i];
5816 $handle_db_line->($dbline{$i});
5818 # Quit if the user hit interrupt.
5820 last BREAKPOINTS_SCAN;
5822 } ## end if (defined $dbline{$i...
5823 } ## end for my $i (1 .. $max)
5824 } ## end for my $file (keys %had_breakpoints)
5829 sub _cmd_L_handle_postponed_breakpoints {
5830 my ($handle_db_line) = @_;
5832 print {$OUT} "Postponed breakpoints in files:\n";
5835 for my $file ( keys %postponed_file ) {
5836 my $db = $postponed_file{$file};
5837 print {$OUT} " $file:\n";
5838 for my $line ( sort { $a <=> $b } keys %$db ) {
5839 print {$OUT} " $line:\n";
5841 $handle_db_line->($db->{$line});
5844 last POSTPONED_SCANS;
5848 last POSTPONED_SCANS;
5859 my ($action_wanted, $break_wanted, $watch_wanted) =
5860 _cmd_L_calc_wanted_flags(shift);
5862 my $handle_db_line = sub {
5865 my ( $stop, $action ) = split( /\0/, $l );
5867 if ($stop and $break_wanted) {
5868 print {$OUT} " break if (", $stop, ")\n"
5871 if ($action && $action_wanted) {
5872 print {$OUT} " action: ", $action, "\n"
5878 # Breaks and actions are found together, so we look in the same place
5880 if ( $break_wanted or $action_wanted ) {
5881 _cmd_L_handle_breakpoints($handle_db_line);
5884 # Look for breaks in not-yet-compiled subs:
5885 if ( %postponed and $break_wanted ) {
5886 print {$OUT} "Postponed breakpoints in subroutines:\n";
5889 for $subname ( keys %postponed ) {
5890 print {$OUT} " $subname\t$postponed{$subname}\n";
5895 } ## end if (%postponed and $break_wanted)
5897 # Find files that have not-yet-loaded breaks:
5898 my @have = map { # Combined keys
5899 keys %{ $postponed_file{$_} }
5900 } keys %postponed_file;
5902 # If there are any, list them.
5903 if ( @have and ( $break_wanted or $action_wanted ) ) {
5904 _cmd_L_handle_postponed_breakpoints($handle_db_line);
5905 } ## end if (@have and ($break_wanted...
5907 if ( %break_on_load and $break_wanted ) {
5908 print {$OUT} "Breakpoints on load:\n";
5909 BREAK_ON_LOAD: for my $filename ( keys %break_on_load ) {
5910 print {$OUT} " $filename\n";
5911 last BREAK_ON_LOAD if $signal;
5913 } ## end if (%break_on_load and...
5915 if ($watch_wanted and ( $trace & 2 )) {
5916 print {$OUT} "Watch-expressions:\n" if @to_watch;
5917 TO_WATCH: for my $expr (@to_watch) {
5918 print {$OUT} " $expr\n";
5919 last TO_WATCH if $signal;
5926 =head3 C<cmd_M> - list modules (command)
5928 Just call C<list_modules>.
5938 =head3 C<cmd_o> - options (command)
5940 If this is just C<o> by itself, we list the current settings via
5941 C<dump_option>. If there's a nonblank value following it, we pass that on to
5942 C<parse_options> for processing.
5948 my $opt = shift || ''; # opt[=val]
5950 # Nonblank. Try to parse and process.
5951 if ( $opt =~ /^(\S.*)/ ) {
5955 # Blank. List the current option settings.
5963 =head3 C<cmd_O> - nonexistent in 5.8.x (command)
5965 Advises the user that the O command has been renamed.
5970 print $OUT "The old O command is now the o command.\n"; # hint
5971 print $OUT "Use 'h' to get current command help synopsis or\n"; #
5972 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; #
5975 =head3 C<cmd_v> - view window (command)
5977 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to
5978 move back a few lines to list the selected line in context. Uses C<cmd_l>
5979 to do the actual listing after figuring out the range of line to request.
5983 use vars qw($preview);
5989 # Extract the line to list around. (Astute readers will have noted that
5990 # this pattern will match whether or not a numeric line is specified,
5991 # which means that we'll always enter this loop (though a non-numeric
5992 # argument results in no action at all)).
5993 if ( $line =~ /^(\d*)$/ ) {
5995 # Total number of lines to list (a windowful).
5996 $incr = $window - 1;
5998 # Set the start to the argument given (if there was one).
6001 # Back up by the context amount.
6004 # Put together a linespec that cmd_l will like.
6005 $line = $start . '-' . ( $start + $incr );
6008 cmd_l( 'l', $line );
6009 } ## end if ($line =~ /^(\d*)$/)
6012 =head3 C<cmd_w> - add a watch expression (command)
6014 The 5.8 version of this command adds a watch expression if one is specified;
6015 it does nothing if entered with no operands.
6017 We extract the expression, save it, evaluate it in the user's context, and
6018 save the value. We'll re-evaluate it each time the debugger passes a line,
6019 and will stop (see the code at the top of the command loop) if the value
6020 of any of the expressions changes.
6024 sub _add_watch_expr {
6028 push @to_watch, $expr;
6030 # Parameterize DB::eval and call it to get the expression's value
6031 # in the user's context. This version can handle expressions which
6032 # return a list value.
6034 # The &-call is here to ascertain the mutability of @_.
6035 my ($val) = join( ' ', &DB::eval);
6036 $val = ( defined $val ) ? "'$val'" : 'undef';
6038 # Save the current value of the expression.
6039 push @old_watch, $val;
6041 # We are now watching expressions.
6050 # Null expression if no arguments.
6051 my $expr = shift || '';
6053 # If expression is not null ...
6054 if ( $expr =~ /\A\S/ ) {
6055 _add_watch_expr($expr);
6056 } ## end if ($expr =~ /^(\S.*)/)
6058 # You have to give one to get one.
6060 print $OUT "Adding a watch-expression requires an expression\n"; # hint
6066 =head3 C<cmd_W> - delete watch expressions (command)
6068 This command accepts either a watch expression to be removed from the list
6069 of watch expressions, or C<*> to delete them all.
6071 If C<*> is specified, we simply empty the watch expression list and the
6072 watch expression value list. We also turn off the bit that says we've got
6075 If an expression (or partial expression) is specified, we pattern-match
6076 through the expressions and remove the ones that match. We also discard
6077 the corresponding values. If no watch expressions are left, we turn off
6078 the I<watching expressions> bit.
6084 my $expr = shift || '';
6087 if ( $expr eq '*' ) {
6092 print $OUT "Deleting all watch expressions ...\n";
6095 @to_watch = @old_watch = ();
6098 # Delete one of them.
6099 elsif ( $expr =~ /^(\S.*)/ ) {
6101 # Where we are in the list.
6104 # For each expression ...
6105 foreach (@to_watch) {
6106 my $val = $to_watch[$i_cnt];
6108 # Does this one match the command argument?
6109 if ( $val eq $expr ) { # =~ m/^\Q$i$/) {
6110 # Yes. Turn it off, and its value too.
6111 splice( @to_watch, $i_cnt, 1 );
6112 splice( @old_watch, $i_cnt, 1 );
6115 } ## end foreach (@to_watch)
6117 # We don't bother to turn watching off because
6118 # a) we don't want to stop calling watchfunction() if it exists
6119 # b) foreach over a null list doesn't do anything anyway
6121 } ## end elsif ($expr =~ /^(\S.*)/)
6123 # No command arguments entered.
6126 "Deleting a watch-expression requires an expression, or '*' for all\n"
6131 ### END of the API section
6133 =head1 SUPPORT ROUTINES
6135 These are general support routines that are used in a number of places
6136 throughout the debugger.
6140 save() saves the user's versions of globals that would mess us up in C<@saved>,
6141 and installs the versions we like better.
6147 # Save eval failure, command failure, extended OS error, output field
6148 # separator, input record separator, output record separator and
6149 # the warning setting.
6150 @saved = ( $@, $!, $^E, $,, $/, $\, $^W );
6152 $, = ""; # output field separator is null string
6153 $/ = "\n"; # input record separator is newline
6154 $\ = ""; # output record separator is null string
6155 $^W = 0; # warnings are off
6158 =head2 C<print_lineinfo> - show where we are now
6160 print_lineinfo prints whatever it is that it is handed; it prints it to the
6161 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows
6162 us to feed line information to a slave editor without messing up the
6167 sub print_lineinfo {
6169 # Make the terminal sensible if we're not the primary debugger.
6170 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$;
6173 # $LINEINFO may be undef if $noTTY is set or some other issue.
6176 print {$LINEINFO} @_;
6178 } ## end sub print_lineinfo
6180 =head2 C<postponed_sub>
6182 Handles setting postponed breakpoints in subroutines once they're compiled.
6183 For breakpoints, we use C<DB::find_sub> to locate the source file and line
6184 range for the subroutine, then mark the file as having a breakpoint,
6185 temporarily switch the C<*dbline> glob over to the source file, and then
6186 search the given range of lines to find a breakable line. If we find one,
6187 we set the breakpoint on it, deleting the breakpoint from C<%postponed>.
6191 # The following takes its argument via $evalarg to preserve current @_
6195 # Get the subroutine name.
6196 my $subname = shift;
6198 # If this is a 'break +<n> if <condition>' ...
6199 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) {
6201 # If there's no offset, use '+0'.
6202 my $offset = $1 || 0;
6204 # find_sub's value is 'fullpath-filename:start-stop'. It's
6205 # possible that the filename might have colons in it too.
6206 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ );
6209 # We got the start line. Add the offset '+<n>' from
6210 # $postponed{subname}.
6213 # Switch to the file this sub is in, temporarily.
6214 local *dbline = $main::{ '_<' . $file };
6216 # No warnings, please.
6217 local $^W = 0; # != 0 is magical below
6219 # This file's got a breakpoint in it.
6220 $had_breakpoints{$file} |= 1;
6222 # Last line in file.
6225 # Search forward until we hit a breakable line or get to
6226 # the end of the file.
6227 ++$i until $dbline[$i] != 0 or $i >= $max;
6229 # Copy the breakpoint in and delete it from %postponed.
6230 $dbline{$i} = delete $postponed{$subname};
6233 # find_sub didn't find the sub.
6236 print $OUT "Subroutine $subname not found.\n";
6239 } ## end if ($postponed{$subname...
6240 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 }
6242 #print $OUT "In postponed_sub for '$subname'.\n";
6243 } ## end sub postponed_sub
6247 Called after each required file is compiled, but before it is executed;
6248 also called if the name of a just-compiled subroutine is a key of
6249 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>,
6250 etc.) into the just-compiled code.
6252 If this is a C<require>'d file, the incoming parameter is the glob
6253 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file.
6255 If it's a subroutine, the incoming parameter is the subroutine name.
6261 # If there's a break, process it.
6262 if ($ImmediateStop) {
6264 # Right, we've stopped. Turn it off.
6267 # Enter the command loop when DB::DB gets called.
6271 # If this is a subroutine, let postponed_sub() deal with it.
6272 if (ref(\$_[0]) ne 'GLOB') {
6273 return postponed_sub(@_);
6276 # Not a subroutine. Deal with the file.
6277 local *dbline = shift;
6278 my $filename = $dbline;
6279 $filename =~ s/^_<//;
6281 $signal = 1, print $OUT "'$filename' loaded...\n"
6282 if $break_on_load{$filename};
6283 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame;
6285 # Do we have any breakpoints to put in this file?
6286 return unless $postponed_file{$filename};
6288 # Yes. Mark this file as having breakpoints.
6289 $had_breakpoints{$filename} |= 1;
6291 # "Cannot be done: insufficient magic" - we can't just put the
6292 # breakpoints saved in %postponed_file into %dbline by assigning
6293 # the whole hash; we have to do it one item at a time for the
6294 # breakpoints to be set properly.
6295 #%dbline = %{$postponed_file{$filename}};
6297 # Set the breakpoints, one at a time.
6300 for $key ( keys %{ $postponed_file{$filename} } ) {
6302 # Stash the saved breakpoint into the current file's magic line array.
6303 $dbline{$key} = ${ $postponed_file{$filename} }{$key};
6306 # This file's been compiled; discard the stored breakpoints.
6307 delete $postponed_file{$filename};
6309 } ## end sub postponed
6313 C<dumpit> is the debugger's wrapper around dumpvar.pl.
6315 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and
6316 a reference to a variable (the thing to be dumped) as its input.
6318 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to
6319 the currently-selected filehandle, thank you very much). The current
6320 values of the package globals C<$single> and C<$trace> are backed up in
6321 lexicals, and they are turned off (this keeps the debugger from trying
6322 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to
6323 preserve its current value and it is set to zero to prevent entry/exit
6324 messages from printing, and C<$doret> is localized as well and set to -2 to
6325 prevent return values from being shown.
6327 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and
6328 tries to load it (note: if you have a C<dumpvar.pl> ahead of the
6329 installed version in C<@INC>, yours will be used instead. Possible security
6332 It then checks to see if the subroutine C<main::dumpValue> is now defined
6333 it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()>
6334 localizes the globals necessary for things to be sane when C<main::dumpValue()>
6335 is called, and picks up the variable to be dumped from the parameter list.
6337 It checks the package global C<%options> to see if there's a C<dumpDepth>
6338 specified. If not, -1 is assumed; if so, the supplied value gets passed on to
6339 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a
6340 structure: -1 means dump everything.
6342 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a
6345 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored
6346 and we then return to the caller.
6352 # Save the current output filehandle and switch to the one
6353 # passed in as the first parameter.
6354 my $savout = select(shift);
6356 # Save current settings of $single and $trace, and then turn them off.
6357 my $osingle = $single;
6358 my $otrace = $trace;
6359 $single = $trace = 0;
6361 # XXX Okay, what do $frame and $doret do, again?
6365 # Load dumpvar.pl unless we've already got the sub we need from it.
6366 unless ( defined &main::dumpValue ) {
6367 do 'dumpvar.pl' or die $@;
6370 # If the load succeeded (or we already had dumpvalue()), go ahead
6372 if ( defined &main::dumpValue ) {
6377 my $maxdepth = shift || $option{dumpDepth};
6378 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth
6379 main::dumpValue( $v, $maxdepth );
6380 } ## end if (defined &main::dumpValue)
6382 # Oops, couldn't load dumpvar.pl.
6385 print $OUT "dumpvar.pl not available.\n";
6388 # Reset $single and $trace to their old values.
6392 # Restore the old filehandle.
6396 =head2 C<print_trace>
6398 C<print_trace>'s job is to print a stack trace. It does this via the
6399 C<dump_trace> routine, which actually does all the ferreting-out of the
6400 stack trace data. C<print_trace> takes care of formatting it nicely and
6401 printing it to the proper filehandle.
6409 The filehandle to print to.
6413 How many frames to skip before starting trace.
6417 How many frames to print.
6421 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments
6425 The original comment below seems to be noting that the traceback may not be
6426 correct if this routine is called in a tied method.
6430 # Tied method do not create a context, so may get wrong message:
6436 # If this is going to a slave editor, but we're not the primary
6437 # debugger, reset it first.
6439 if $fh eq $LINEINFO # slave editor
6440 and $LINEINFO eq $OUT # normal output
6441 and $term_pid != $$; # not the primary
6443 # Collect the actual trace information to be formatted.
6444 # This is an array of hashes of subroutine call info.
6445 my @sub = dump_trace( $_[0] + 1, $_[1] );
6447 # Grab the "short report" flag from @_.
6448 my $short = $_[2]; # Print short report, next one for sub name
6450 # Run through the traceback info, format it, and print it.
6452 for my $i (0 .. $#sub) {
6454 # Drop out if the user has lost interest and hit control-C.
6457 # Set the separator so arrays print nice.
6460 # Grab and stringify the arguments if they are there.
6462 defined $sub[$i]{args}
6463 ? "(@{ $sub[$i]{args} })"
6466 # Shorten them up if $maxtrace says they're too long.
6467 $args = ( substr $args, 0, $maxtrace - 3 ) . '...'
6468 if length $args > $maxtrace;
6470 # Get the file name.
6471 my $file = $sub[$i]{file};
6473 # Put in a filename header if short is off.
6474 $file = $file eq '-e' ? $file : "file '$file'" unless $short;
6476 # Get the actual sub's name, and shorten to $maxtrace's requirement.
6477 $s = $sub[$i]{'sub'};
6478 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace;
6480 # Short report uses trimmed file and sub names.
6482 my $sub = @_ >= 4 ? $_[3] : $s;
6483 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n";
6484 } ## end if ($short)
6486 # Non-short report includes full names.
6488 print $fh "$sub[$i]{context} = $s$args"
6489 . " called from $file"
6490 . " line $sub[$i]{line}\n";
6492 } ## end for my $i (0 .. $#sub)
6493 } ## end sub print_trace
6495 =head2 dump_trace(skip[,count])
6497 Actually collect the traceback information available via C<caller()>. It does
6498 some filtering and cleanup of the data, but mostly it just collects it to
6499 make C<print_trace()>'s job easier.
6501 C<skip> defines the number of stack frames to be skipped, working backwards
6502 from the most current. C<count> determines the total number of frames to
6503 be returned; all of them (well, the first 10^9) are returned if C<count>
6506 This routine returns a list of hashes, from most-recent to least-recent
6507 stack frame. Each has the following keys and values:
6511 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array)
6513 =item * C<sub> - subroutine name, or C<eval> information
6515 =item * C<args> - undef, or a reference to an array of arguments
6517 =item * C<file> - the file in which this item was defined (if any)
6519 =item * C<line> - the line on which it was defined
6525 sub _dump_trace_calc_saved_single_arg
6527 my ($nothard, $arg) = @_;
6530 if ( not defined $arg ) { # undefined parameter
6534 elsif ( $nothard and tied $arg ) { # tied parameter
6537 elsif ( $nothard and $type = ref $arg ) { # reference
6538 return "ref($type)";
6540 else { # can be stringified
6542 "$arg"; # Safe to stringify now - should not call f().
6544 # Backslash any single-quotes or backslashes.
6547 # Single-quote it unless it's a number or a colon-separated
6550 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
6552 # Turn high-bit characters into meta-whatever, and controls into like
6554 require 'meta_notation.pm';
6555 $_ = _meta_notation($_) if /[[:^print:]]/a;
6561 sub _dump_trace_calc_save_args {
6565 map { _dump_trace_calc_saved_single_arg($nothard, $_) } @args
6571 # How many levels to skip.
6574 # How many levels to show. (1e9 is a cheap way of saying "all of them";
6575 # it's unlikely that we'll have more than a billion stack frames. If you
6576 # do, you've got an awfully big machine...)
6577 my $count = shift || 1e9;
6579 # We increment skip because caller(1) is the first level *back* from
6580 # the current one. Add $skip to the count of frames so we have a
6581 # simple stop criterion, counting from $skip to $count+$skip.
6585 # These variables are used to capture output from caller();
6586 my ( $p, $file, $line, $sub, $h, $context );
6588 my ( $e, $r, @sub, $args );
6590 # XXX Okay... why'd we do that?
6591 my $nothard = not $frame & 8;
6594 # Do not want to trace this.
6595 my $otrace = $trace;
6598 # Start out at the skip count.
6599 # If we haven't reached the number of frames requested, and caller() is
6600 # still returning something, stay in the loop. (If we pass the requested
6601 # number of stack frames, or we run out - caller() returns nothing - we
6603 # Up the stack frame index to go back one more level each time.
6607 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ;
6612 # Go through the arguments and save them for later.
6613 my $save_args = _dump_trace_calc_save_args($nothard);
6615 # If context is true, this is array (@)context.
6616 # If context is false, this is scalar ($) context.
6617 # If neither, context isn't defined. (This is apparently a 'can't
6619 $context = $context ? '@' : ( defined $context ? "\$" : '.' );
6621 # if the sub has args ($h true), make an anonymous array of the
6623 $args = $h ? $save_args : undef;
6625 # remove trailing newline-whitespace-semicolon-end of line sequence
6626 # from the eval text, if any.
6627 $e =~ s/\n\s*\;\s*\Z// if $e;
6629 # Escape backslashed single-quotes again if necessary.
6630 $e =~ s/([\\\'])/\\$1/g if $e;
6632 # if the require flag is true, the eval text is from a require.
6634 $sub = "require '$e'";
6637 # if it's false, the eval text is really from an eval.
6638 elsif ( defined $r ) {
6642 # If the sub is '(eval)', this is a block eval, meaning we don't
6643 # know what the eval'ed text actually was.
6644 elsif ( $sub eq '(eval)' ) {
6645 $sub = "eval {...}";
6648 # Stick the collected information into @sub as an anonymous hash.
6652 context => $context,
6660 # Stop processing frames if the user hit control-C.
6662 } ## end for ($i = $skip ; $i < ...
6664 # Restore the trace value again.
6667 } ## end sub dump_trace
6671 C<action()> takes input provided as the argument to an add-action command,
6672 either pre- or post-, and makes sure it's a complete command. It doesn't do
6673 any fancy parsing; it just keeps reading input until it gets a string
6674 without a trailing backslash.
6681 while ( $action =~ s/\\$// ) {
6683 # We have a backslash on the end. Read more.
6685 } ## end while ($action =~ s/\\$//)
6687 # Return the assembled action.
6693 This routine mostly just packages up a regular expression to be used
6694 to check that the thing it's being matched against has properly-matched
6697 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which
6698 speeds things up by only creating the qr//'ed expression once; if it's
6699 already defined, we don't try to define it again. A speed hack.
6703 use vars qw($balanced_brace_re);
6707 # I hate using globals!
6708 $balanced_brace_re ||= qr{
6711 (?> [^{}] + ) # Non-parens without backtracking
6713 (??{ $balanced_brace_re }) # Group with matching parens
6717 return $_[0] !~ m/$balanced_brace_re/;
6718 } ## end sub unbalanced
6722 C<gets()> is a primitive (very primitive) routine to read continuations.
6723 It was devised for reading continuations for actions.
6724 it just reads more input with C<readline()> and returns it.
6729 return DB::readline("cont: ");
6732 =head2 C<_db_system()> - handle calls to<system()> without messing up the debugger
6734 The C<system()> function assumes that it can just go ahead and use STDIN and
6735 STDOUT, but under the debugger, we want it to use the debugger's input and
6738 C<_db_system()> socks away the program's STDIN and STDOUT, and then substitutes
6739 the debugger's IN and OUT filehandles for them. It does the C<system()> call,
6740 and then puts everything back again.
6746 # We save, change, then restore STDIN and STDOUT to avoid fork() since
6747 # some non-Unix systems can do system() but have problems with fork().
6748 open( SAVEIN, "<&STDIN" ) || _db_warn("Can't save STDIN");
6749 open( SAVEOUT, ">&STDOUT" ) || _db_warn("Can't save STDOUT");
6750 open( STDIN, "<&IN" ) || _db_warn("Can't redirect STDIN");
6751 open( STDOUT, ">&OUT" ) || _db_warn("Can't redirect STDOUT");
6753 # XXX: using csh or tcsh destroys sigint retvals!
6755 open( STDIN, "<&SAVEIN" ) || _db_warn("Can't restore STDIN");
6756 open( STDOUT, ">&SAVEOUT" ) || _db_warn("Can't restore STDOUT");
6760 # most of the $? crud was coping with broken cshisms
6762 _db_warn( "(Command exited ", ( $? >> 8 ), ")\n" );
6766 "(Command died of SIG#",
6768 ( ( $? & 128 ) ? " -- core dumped" : "" ),
6777 *system = \&_db_system;
6779 =head1 TTY MANAGEMENT
6781 The subs here do some of the terminal management for multiple debuggers.
6785 Top-level function called when we want to set up a new terminal for use
6788 If the C<noTTY> debugger option was set, we'll either use the terminal
6789 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous>
6790 to find one. If we're a forked debugger, we call C<resetterm> to try to
6791 get a whole new terminal if we can.
6793 In either case, we set up the terminal next. If the C<ReadLine> option was
6794 true, we'll get a C<Term::ReadLine> object for the current terminal and save
6795 the appropriate attributes. We then
6799 use vars qw($ornaments);
6800 use vars qw($rl_attribs);
6804 # Load Term::Readline, but quietly; don't debug it and don't trace it.
6807 require Term::ReadLine;
6809 # If noTTY is set, but we have a TTY name, go ahead and hook up to it.
6812 my ( $i, $o ) = split $tty, /,/;
6813 $o = $i unless defined $o;
6814 open( IN, "<$i" ) or die "Cannot open TTY '$i' for read: $!";
6815 open( OUT, ">$o" ) or die "Cannot open TTY '$o' for write: $!";
6821 # We don't have a TTY - try to find one via Term::Rendezvous.
6823 require Term::Rendezvous;
6825 # See if we have anything to pass to Term::Rendezvous.
6826 # Use $HOME/.perldbtty$$ if not.
6827 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$";
6829 # Rendezvous and get the filehandles.
6830 my $term_rv = Term::Rendezvous->new( $rv );
6832 $OUT = $term_rv->OUT;
6833 } ## end else [ if ($tty)
6834 } ## end if ($notty)
6836 # We're a daughter debugger. Try to fork off another TTY.
6837 if ( $term_pid eq '-1' ) { # In a TTY with another debugger
6841 # If we shouldn't use Term::ReadLine, don't.
6843 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6846 # We're using Term::ReadLine. Get all the attributes for this terminal.
6848 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6850 $rl_attribs = $term->Attribs;
6851 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}'
6852 if defined $rl_attribs->{basic_word_break_characters}
6853 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1;
6854 $rl_attribs->{special_prefixes} = '$@&%';
6855 $rl_attribs->{completer_word_break_characters} .= '$@&%';
6856 $rl_attribs->{completion_function} = \&db_complete;
6857 } ## end else [ if (!$rl)
6859 # Set up the LINEINFO filehandle.
6860 $LINEINFO = $OUT unless defined $LINEINFO;
6861 $lineinfo = $console unless defined $lineinfo;
6867 if ( $term->Features->{setHistory} and "@hist" ne "?" ) {
6868 $term->SetHistory(@hist);
6871 # XXX Ornaments are turned on unconditionally, which is not
6872 # always a good thing.
6873 ornaments($ornaments) if defined $ornaments;
6875 } ## end sub setterm
6878 $histfile //= option_val("HistFile", undef);
6879 return unless defined $histfile;
6880 open my $fh, "<", $histfile or return;
6891 return unless defined $histfile;
6892 eval { require File::Path } or return;
6893 eval { require File::Basename } or return;
6894 File::Path::mkpath(File::Basename::dirname($histfile));
6895 open my $fh, ">", $histfile or die "Could not open '$histfile': $!";
6896 $histsize //= option_val("HistSize",100);
6897 my @copy = grep { $_ ne '?' } @hist;
6898 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0;
6899 for ($start .. $#copy) {
6900 print $fh "$copy[$_]\n";
6902 close $fh or die "Could not write '$histfile': $!";
6905 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS
6907 When the process being debugged forks, or the process invokes a command
6908 via C<system()> which starts a new debugger, we need to be able to get a new
6909 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes
6910 fight over the terminal, and you can never quite be sure who's going to get the
6911 input you're typing.
6913 C<get_fork_TTY> is a glob-aliased function which calls the real function that
6914 is tasked with doing all the necessary operating system mojo to get a new
6915 TTY (and probably another window) and to direct the new debugger to read and
6918 The debugger provides C<get_fork_TTY> functions which work for TCP
6919 socket servers, X11, OS/2, and Mac OS X. Other systems are not
6920 supported. You are encouraged to write C<get_fork_TTY> functions which
6921 work for I<your> platform and contribute them.
6923 =head3 C<socket_get_fork_TTY>
6927 sub connect_remoteport {
6930 my $socket = IO::Socket::INET->new(
6932 PeerAddr => $remoteport,
6936 die "Unable to connect to remote host: $remoteport\n";
6941 sub socket_get_fork_TTY {
6942 $tty = $LINEINFO = $IN = $OUT = connect_remoteport();
6944 # Do I need to worry about setting $term?
6946 reset_IN_OUT( $IN, $OUT );
6950 =head3 C<xterm_get_fork_TTY>
6952 This function provides the C<get_fork_TTY> function for X11. If a
6953 program running under the debugger forks, a new <xterm> window is opened and
6954 the subsidiary debugger is directed there.
6956 The C<open()> call is of particular note here. We have the new C<xterm>
6957 we're spawning route file number 3 to STDOUT, and then execute the C<tty>
6958 command (which prints the device name of the TTY we'll want to use for input
6959 and output to STDOUT, then C<sleep> for a very long time, routing this output
6960 to file number 3. This way we can simply read from the <XT> filehandle (which
6961 is STDOUT from the I<commands> we ran) to get the TTY we want to use.
6963 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are
6968 sub xterm_get_fork_TTY {
6969 ( my $name = $0 ) =~ s,^.*[/\\],,s;
6971 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\
6974 # Get the output from 'tty' and clean it up a little.
6978 $pidprompt = ''; # Shown anyway in titlebar
6980 # We need $term defined or we can not switch to the newly created xterm
6981 if ($tty ne '' && !defined $term) {
6982 require Term::ReadLine;
6984 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
6987 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
6990 # There's our new TTY.
6992 } ## end sub xterm_get_fork_TTY
6994 =head3 C<os2_get_fork_TTY>
6996 XXX It behooves an OS/2 expert to write the necessary documentation for this!
7000 # This example function resets $IN, $OUT itself
7002 sub os2_get_fork_TTY { # A simplification of the following (and works without):
7004 ( my $name = $0 ) =~ s,^.*[/\\],,s;
7005 my %opt = ( title => "Daughter Perl debugger $pids $name",
7006 ($rl ? (read_by_key => 1) : ()) );
7007 require OS2::Process;
7008 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) }
7010 $pidprompt = ''; # Shown anyway in titlebar
7011 reset_IN_OUT($in, $out);
7013 return ''; # Indicate that reset_IN_OUT is called
7014 } ## end sub os2_get_fork_TTY
7016 =head3 C<macosx_get_fork_TTY>
7018 The Mac OS X version uses AppleScript to tell Terminal.app to create
7023 # Notes about Terminal.app's AppleScript support,
7024 # (aka things that might break in future OS versions).
7026 # The "do script" command doesn't return a reference to the new window
7027 # it creates, but since it appears frontmost and windows are enumerated
7028 # front to back, we can use "first window" === "window 1".
7030 # Since "do script" is implemented by supplying the argument (plus a
7031 # return character) as terminal input, there's a potential race condition
7032 # where the debugger could beat the shell to reading the command.
7033 # To prevent this, we wait for the screen to clear before proceeding.
7036 # There's no direct accessor for the tty device name, so we fiddle
7037 # with the window title options until it says what we want.
7040 # There _is_ a direct accessor for the tty device name, _and_ there's
7041 # a new possible component of the window title (the name of the settings
7042 # set). A separate version is needed.
7044 my @script_versions=
7046 ([237, <<'__LEOPARD__'],
7047 tell application "Terminal"
7048 do script "clear;exec sleep 100000"
7049 tell first tab of first window
7051 set custom title to "forked perl debugger"
7052 set title displays custom title to true
7053 repeat while (length of first paragraph of (get contents)) > 0
7061 [100, <<'__JAGUAR_TIGER__'],
7062 tell application "Terminal"
7063 do script "clear;exec sleep 100000"
7065 set title displays shell path to false
7066 set title displays window size to false
7067 set title displays file name to false
7068 set title displays device name to true
7069 set title displays custom title to true
7070 set custom title to ""
7071 copy "/dev/" & name to thetty
7072 set custom title to "forked perl debugger"
7073 repeat while (length of first paragraph of (get contents)) > 0
7083 sub macosx_get_fork_TTY
7085 my($version,$script,$pipe,$tty);
7087 return unless $version=$ENV{TERM_PROGRAM_VERSION};
7088 foreach my $entry (@script_versions) {
7089 if ($version>=$entry->[0]) {
7090 $script=$entry->[1];
7094 return unless defined($script);
7095 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script);
7096 $tty=readline($pipe);
7098 return unless defined($tty) && $tty =~ m(^/dev/);
7103 =head3 C<tmux_get_fork_TTY>
7105 Creates a split window for subprocesses when a process running under the
7106 perl debugger in Tmux forks.
7110 sub tmux_get_fork_TTY {
7111 return unless $ENV{TMUX};
7115 my $status = open $pipe, '-|', 'tmux', 'split-window',
7116 '-P', '-F', '#{pane_tty}', 'sleep 100000';
7128 if ( !defined $term ) {
7129 require Term::ReadLine;
7131 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
7134 $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
7142 =head2 C<create_IN_OUT($flags)>
7144 Create a new pair of filehandles, pointing to a new TTY. If impossible,
7145 try to diagnose why.
7151 =item * 1 - Don't know how to create a new TTY.
7153 =item * 2 - Debugger has forked, but we can't get a new TTY.
7155 =item * 4 - standard debugger startup is happening.
7161 use vars qw($fork_TTY);
7163 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there
7165 # If we know how to get a new TTY, do it! $in will have
7166 # the TTY name if get_fork_TTY works.
7167 my $in = get_fork_TTY(@_) if defined &get_fork_TTY;
7169 # It used to be that
7170 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility
7172 if ( not defined $in ) {
7175 # We don't know how.
7176 print_help(<<EOP) if $why == 1;
7177 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########>
7181 print_help(<<EOP) if $why == 2;
7182 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########>
7183 This may be an asynchronous session, so the parent debugger may be active.
7186 # Note that both debuggers are fighting over the same input.
7187 print_help(<<EOP) if $why != 4;
7188 Since two debuggers fight for the same TTY, input is severely entangled.
7192 I know how to switch the output to a different window in xterms, OS/2
7193 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name
7194 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
7195 B<DB::get_fork_TTY()> returning this.
7197 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window
7198 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>.
7201 } ## end if (not defined $in)
7202 elsif ( $in ne '' ) {
7206 $console = ''; # Indicate no need to open-from-the-console
7209 } ## end sub create_IN_OUT
7213 Handles rejiggering the prompt when we've forked off a new debugger.
7215 If the new debugger happened because of a C<system()> that invoked a
7216 program under the debugger, the arrow between the old pid and the new
7217 in the prompt has I<two> dashes instead of one.
7219 We take the current list of pids and add this one to the end. If there
7220 isn't any list yet, we make one up out of the initial pid associated with
7221 the terminal and our new pid, sticking an arrow (either one-dashed or
7222 two dashed) in between them.
7224 If C<CreateTTY> is off, or C<resetterm> was called with no arguments,
7225 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead
7230 sub resetterm { # We forked, so we need a different TTY
7232 # Needs to be passed to create_IN_OUT() as well.
7235 # resetterm(2): got in here because of a system() starting a debugger.
7236 # resetterm(1): just forked.
7237 my $systemed = $in > 1 ? '-' : '';
7239 # If there's already a list of pids, add this to the end.
7241 $pids =~ s/\]/$systemed->$$]/;
7244 # No pid list. Time to make one.
7246 $pids = "[$term_pid->$$]";
7249 # The prompt we're going to be using for this debugger.
7252 # We now 0wnz this terminal.
7255 # Just return if we're not supposed to try to create a new TTY.
7256 return unless $CreateTTY & $in;
7258 # Try to create a new IN/OUT pair.
7260 } ## end sub resetterm
7264 First, we handle stuff in the typeahead buffer. If there is any, we shift off
7265 the next line, print a message saying we got it, add it to the terminal
7266 history (if possible), and return it.
7268 If there's nothing in the typeahead buffer, check the command filehandle stack.
7269 If there are any filehandles there, read from the last one, and return the line
7270 if we got one. If not, we pop the filehandle off and close it, and try the
7271 next one up the stack.
7273 If we've emptied the filehandle stack, we check to see if we've got a socket
7274 open, and we read that and return it if we do. If we don't, we just call the
7275 core C<readline()> and return its value.
7281 # Localize to prevent it from being smashed in the program being debugged.
7284 # If there are stacked filehandles to read from ...
7285 # (Handle it before the typeahead, because we may call source/etc. from
7289 # Read from the last one in the stack.
7290 my $line = CORE::readline( $cmdfhs[-1] );
7292 # If we got a line ...
7294 ? ( print $OUT ">> $line" and return $line ) # Echo and return
7295 : close pop @cmdfhs; # Pop and close
7296 } ## end while (@cmdfhs)
7298 # Pull a line out of the typeahead if there's stuff there.
7301 # How many lines left.
7302 my $left = @typeahead;
7304 # Get the next line.
7305 my $got = shift @typeahead;
7307 # Print a message saying we got input from the typeahead.
7309 print $OUT "auto(-$left)", shift, $got, "\n";
7311 # Add it to the terminal history (if possible).
7312 $term->AddHistory($got)
7314 and defined $term->Features->{addHistory};
7316 } ## end if (@typeahead)
7318 # We really need to read some input. Turn off entry/exit trace and
7319 # return value printing.
7323 # Nothing on the filehandle stack. Socket?
7324 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) {
7326 # Send anything we have to send.
7327 $OUT->write( join( '', @_ ) );
7329 # Receive anything there is to receive.
7334 while ($first_time or (length($buf) && ($stuff .= $buf) !~ /\n/))
7337 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?"
7338 # XXX Don't know. You tell me.
7343 } ## end if (ref $OUT and UNIVERSAL::isa...
7345 # No socket. Just read from the terminal.
7347 return $term->readline(@_);
7349 } ## end sub readline
7351 =head1 OPTIONS SUPPORT ROUTINES
7353 These routines handle listing and setting option values.
7355 =head2 C<dump_option> - list the current value of an option setting
7357 This routine uses C<option_val> to look up the value for an option.
7358 It cleans up escaped single-quotes and then displays the option and
7364 my ( $opt, $val ) = @_;
7365 $val = option_val( $opt, 'N/A' );
7366 $val =~ s/([\\\'])/\\$1/g;
7367 printf $OUT "%20s = '%s'\n", $opt, $val;
7368 } ## end sub dump_option
7370 sub options2remember {
7371 foreach my $k (@RememberOnROptions) {
7372 $option{$k} = option_val( $k, 'N/A' );
7377 =head2 C<option_val> - find the current value of an option
7379 This can't just be a simple hash lookup because of the indirect way that
7380 the option values are stored. Some are retrieved by calling a subroutine,
7381 some are just variables.
7383 You must supply a default value to be used in case the option isn't set.
7388 my ( $opt, $default ) = @_;
7391 # Does this option exist, and is it a variable?
7392 # If so, retrieve the value via the value in %optionVars.
7393 if ( defined $optionVars{$opt}
7394 and defined ${ $optionVars{$opt} } )
7396 $val = ${ $optionVars{$opt} };
7399 # Does this option exist, and it's a subroutine?
7400 # If so, call the subroutine via the ref in %optionAction
7401 # and capture the value.
7402 elsif ( defined $optionAction{$opt}
7403 and defined &{ $optionAction{$opt} } )
7405 $val = &{ $optionAction{$opt} }();
7408 # If there's an action or variable for the supplied option,
7409 # but no value was set, use the default.
7410 elsif (defined $optionAction{$opt} and not defined $option{$opt}
7411 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } )
7416 # Otherwise, do the simple hash lookup.
7418 $val = $option{$opt};
7421 # If the value isn't defined, use the default.
7422 # Then return whatever the value is.
7423 $val = $default unless defined $val;
7425 } ## end sub option_val
7427 =head2 C<parse_options>
7429 Handles the parsing and execution of option setting/displaying commands.
7431 An option entered by itself is assumed to be I<set me to 1> (the default value)
7432 if the option is a boolean one. If not, the user is prompted to enter a valid
7433 value or to query the current value (via C<option? >).
7435 If C<option=value> is entered, we try to extract a quoted string from the
7436 value (if it is quoted). If it's not, we just use the whole value as-is.
7438 We load any modules required to service this option, and then we set it: if
7439 it just gets stuck in a variable, we do that; if there's a subroutine to
7440 handle setting the option, we call that.
7442 Finally, if we're running in interactive mode, we display the effect of the
7443 user's command back to the terminal, skipping this if we're setting things
7444 during initialization.
7454 # These options need a value. Don't allow them to be clobbered by accident.
7455 my %opt_needs_val = map { ( $_ => 1 ) } qw{
7456 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize
7457 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet
7460 while (length($s)) {
7463 # Clean off excess leading whitespace.
7464 $s =~ s/^\s+// && next;
7466 # Options are always all word characters, followed by a non-word
7468 if ($s !~ s/^(\w+)(\W?)//) {
7469 print {$OUT} "Invalid option '$s'\n";
7472 my ( $opt, $sep ) = ( $1, $2 );
7474 # Make sure that such an option exists.
7475 my $matches = ( grep { /^\Q$opt/ && ( $option = $_ ) } @options )
7476 || ( grep { /^\Q$opt/i && ( $option = $_ ) } @options );
7479 print {$OUT} "Unknown option '$opt'\n";
7483 print {$OUT} "Ambiguous option '$opt'\n";
7488 # '?' as separator means query, but must have whitespace after it.
7489 if ( "?" eq $sep ) {
7491 print {$OUT} "Option query '$opt?' followed by non-space '$s'\n" ;
7496 #&dump_option($opt);
7497 } ## end if ("?" eq $sep)
7499 # Separator is whitespace (or just a carriage return).
7500 # They're going for a default, which we assume is 1.
7501 elsif ( $sep !~ /\S/ ) {
7503 $val = "1"; # this is an evil default; make 'em set it!
7506 # Separator is =. Trying to set a value.
7507 elsif ( $sep eq "=" ) {
7509 # If quoted, extract a quoted string.
7510 if ($s =~ s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) {
7512 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g;
7515 # Not quoted. Use the whole thing. Warn about 'option='.
7519 print OUT qq(Option better cleared using $opt=""\n)
7521 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x)
7523 } ## end elsif ($sep eq "=")
7525 # "Quoted" with [], <>, or {}.
7526 else { #{ to "let some poor schmuck bounce on the % key in B<vi>."
7528 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #}
7529 $s =~ s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)//
7530 or print( $OUT "Unclosed option value '$opt$sep$_'\n" ), last;
7531 ( $val = $1 ) =~ s/\\([\\$end])/$1/g;
7532 } ## end else [ if ("?" eq $sep)
7534 # Exclude non-booleans from getting set to 1 by default.
7535 if ( $opt_needs_val{$option} && $val_defaulted ) {
7536 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O';
7538 "Option '$opt' is non-boolean. Use '$cmd $option=VAL' to set, '$cmd $option?' to query\n";
7540 } ## end if ($opt_needs_val{$option...
7542 # Save the option value.
7543 $option{$option} = $val if defined $val;
7545 # Load any module that this option requires.
7546 if ( defined($optionRequire{$option}) && defined($val) ) {
7550 require '$optionRequire{$option}';
7552 } || die $@ # XXX: shouldn't happen
7556 # Stick it in the proper variable if it goes in a variable.
7557 if (defined($optionVars{$option}) && defined($val)) {
7558 ${ $optionVars{$option} } = $val;
7561 # Call the appropriate sub if it gets set via sub.
7562 if (defined($optionAction{$option})
7563 && defined (&{ $optionAction{$option} })
7566 &{ $optionAction{$option} }($val);
7569 # Not initialization - echo the value we set it to.
7570 dump_option($option) if ($OUT ne \*STDERR);
7571 } ## end while (length)
7572 } ## end sub parse_options
7574 =head1 RESTART SUPPORT
7576 These routines are used to store (and restore) lists of items in environment
7577 variables during a restart.
7581 Set_list packages up items to be stored in a set of environment variables
7582 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing
7583 the values). Values outside the standard ASCII charset are stored by encoding
7584 them as hexadecimal values.
7589 my ( $stem, @list ) = @_;
7592 # VAR_n: how many we have. Scalar assignment gets the number of items.
7593 $ENV{"${stem}_n"} = @list;
7595 # Grab each item in the list, escape the backslashes, encode the non-ASCII
7596 # as hex, and then save in the appropriate VAR_0, VAR_1, etc.
7597 for my $i ( 0 .. $#list ) {
7599 $val =~ s/\\/\\\\/g;
7600 no warnings 'experimental::regex_sets';
7601 $val =~ s/ ( (?[ [\000-\xFF] & [:^print:] ]) ) /
7602 "\\0x" . unpack('H2',$1)/xaeg;
7603 $ENV{"${stem}_$i"} = $val;
7604 } ## end for $i (0 .. $#list)
7605 } ## end sub set_list
7609 Reverse the set_list operation: grab VAR_n to see how many we should be getting
7610 back, and then pull VAR_0, VAR_1. etc. back out.
7617 my $n = delete $ENV{"${stem}_n"};
7619 for my $i ( 0 .. $n - 1 ) {
7620 $val = delete $ENV{"${stem}_$i"};
7621 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge;
7625 } ## end sub get_list
7627 =head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT
7631 The C<catch()> subroutine is the essence of fast and low-impact. We simply
7632 set an already-existing global scalar variable to a constant value. This
7633 avoids allocating any memory possibly in the middle of something that will
7634 get all confused if we do, particularly under I<unsafe signals>.
7640 return; # Put nothing on the stack - malloc/free land!
7645 C<warn> emits a warning, by joining together its arguments and printing
7646 them, with couple of fillips.
7648 If the composited message I<doesn't> end with a newline, we automatically
7649 add C<$!> and a newline to the end of the message. The subroutine expects $OUT
7650 to be set to the filehandle to be used to output warnings; it makes no
7651 assumptions about what filehandles are available.
7656 my ($msg) = join( "", @_ );
7657 $msg .= ": $!\n" unless $msg =~ /\n$/;
7664 =head1 INITIALIZATION TTY SUPPORT
7666 =head2 C<reset_IN_OUT>
7668 This routine handles restoring the debugger's input and output filehandles
7669 after we've tried and failed to move them elsewhere. In addition, it assigns
7670 the debugger's output filehandle to $LINEINFO if it was already open there.
7675 my $switch_li = $LINEINFO eq $OUT;
7677 # If there's a term and it's able to get a new tty, try to get one.
7678 if ( $term and $term->Features->{newTTY} ) {
7679 ( $IN, $OUT ) = ( shift, shift );
7680 $term->newTTY( $IN, $OUT );
7683 # This term can't get a new tty now. Better luck later.
7685 _db_warn("Too late to set IN/OUT filehandles, enabled on next 'R'!\n");
7688 # Set the filehndles up as they were.
7690 ( $IN, $OUT ) = ( shift, shift );
7693 # Unbuffer the output filehandle.
7696 # Point LINEINFO to the same output filehandle if it was there before.
7697 $LINEINFO = $OUT if $switch_li;
7698 } ## end sub reset_IN_OUT
7700 =head1 OPTION SUPPORT ROUTINES
7702 The following routines are used to process some of the more complicated
7707 Sets the input and output filehandles to the specified files or pipes.
7708 If the terminal supports switching, we go ahead and do it. If not, and
7709 there's already a terminal in place, we save the information to take effect
7712 If there's no terminal yet (for instance, during debugger initialization),
7713 we go ahead and set C<$console> and C<$tty> to the file indicated.
7719 if ( @_ and $term and $term->Features->{newTTY} ) {
7721 # This terminal supports switching to a new TTY.
7722 # Can be a list of two files, or on string containing both names,
7724 # XXX Should this perhaps be an assignment from @_?
7725 my ( $in, $out ) = shift;
7728 # Split list apart if supplied.
7729 ( $in, $out ) = split /,/, $in, 2;
7733 # Use the same file for both input and output.
7737 # Open file onto the debugger's filehandles, if you can.
7738 open IN, $in or die "cannot open '$in' for read: $!";
7739 open OUT, ">$out" or die "cannot open '$out' for write: $!";
7741 # Swap to the new filehandles.
7742 reset_IN_OUT( \*IN, \*OUT );
7744 # Save the setting for later.
7746 } ## end if (@_ and $term and $term...
7748 # Terminal doesn't support new TTY, or doesn't support readline.
7749 # Can't do it now, try restarting.
7751 _db_warn("Too late to set TTY, enabled on next 'R'!\n");
7754 # Useful if done through PERLDB_OPTS:
7755 $console = $tty = shift if @_;
7757 # Return whatever the TTY is.
7763 Sets the C<$notty> global, controlling whether or not the debugger tries to
7764 get a terminal to read from. If called after a terminal is already in place,
7765 we save the value to use it if we're restarted.
7771 _db_warn("Too late to set noTTY, enabled on next 'R'!\n") if @_;
7773 $notty = shift if @_;
7779 Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub>
7780 (essentially, no C<readline> processing on this I<terminal>). Otherwise, we
7781 use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save
7782 the value in case a restart is done so we can change it then.
7788 _db_warn("Too late to set ReadLine, enabled on next 'R'!\n") if @_;
7792 } ## end sub ReadLine
7794 =head2 C<RemotePort>
7796 Sets the port that the debugger will try to connect to when starting up.
7797 If the terminal's already been set up, we can't do it, but we remember the
7798 setting in case the user does a restart.
7804 _db_warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_;
7806 $remoteport = shift if @_;
7808 } ## end sub RemotePort
7812 Checks with the terminal to see if C<Tk> is running, and returns true or
7813 false. Returns false if the current terminal doesn't support C<readline>.
7818 if ( ${ $term->Features }{tkRunning} ) {
7819 return $term->tkRunning(@_);
7823 print $OUT "tkRunning not supported by current ReadLine package.\n";
7826 } ## end sub tkRunning
7830 Sets nonstop mode. If a terminal's already been set up, it's too late; the
7831 debugger remembers the setting in case you restart, though.
7837 _db_warn("Too late to set up NonStop mode, enabled on next 'R'!\n")
7840 $runnonstop = shift if @_;
7842 } ## end sub NonStop
7846 _db_warn("Some flag changes could not take effect until next 'R'!\n")
7849 $^P = parse_DollarCaretP_flags(shift) if @_;
7850 expand_DollarCaretP_flags($^P);
7855 Set up the C<$pager> variable. Adds a pipe to the front unless there's one
7863 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/;
7870 Sets the shell escape command, and generates a printable copy to be used
7877 # If we got an argument, meta-quote it, and add '\b' if it
7878 # ends in a word character.
7880 $sh = quotemeta shift;
7881 $sh .= "\\b" if $sh =~ /\w$/;
7884 # Generate the printable version for the help:
7885 $psh = $sh; # copy it
7886 $psh =~ s/\\b$//; # Take off trailing \b if any
7887 $psh =~ s/\\(.)/$1/g; # De-escape
7888 $psh; # return the printable version
7889 } ## end sub shellBang
7893 If the terminal has its own ornaments, fetch them. Otherwise accept whatever
7894 was passed as the argument. (This means you can't override the terminal's
7900 if ( defined $term ) {
7902 # We don't want to show warning backtraces, but we do want die() ones.
7903 local $warnLevel = 0;
7904 local $dieLevel = 1;
7906 # No ornaments if the terminal doesn't support them.
7907 if (not $term->Features->{ornaments}) {
7911 return (eval { $term->ornaments(@_) } || '');
7914 # Use what was passed in if we can't determine it ourselves.
7921 } ## end sub ornaments
7923 =head2 C<recallCommand>
7925 Sets the recall command, and builds a printable version which will appear in
7932 # If there is input, metaquote it. Add '\b' if it ends with a word
7935 $rc = quotemeta shift;
7936 $rc .= "\\b" if $rc =~ /\w$/;
7939 # Build it into a printable version.
7940 $prc = $rc; # Copy it
7941 $prc =~ s/\\b$//; # Remove trailing \b
7942 $prc =~ s/\\(.)/$1/g; # Remove escapes
7943 return $prc; # Return the printable version
7944 } ## end sub recallCommand
7946 =head2 C<LineInfo> - where the line number information goes
7948 Called with no arguments, returns the file or pipe that line info should go to.
7950 Called with an argument (a file or a pipe), it opens that onto the
7951 C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the
7952 file or pipe again to the caller.
7960 # If this is a valid "thing to be opened for output", tack a
7961 # '>' onto the front.
7962 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo";
7964 # If this is a pipe, the stream points to a slave editor.
7965 $slave_editor = ( $stream =~ /^\|/ );
7967 my $new_lineinfo_fh;
7968 # Open it up and unbuffer it.
7969 open ($new_lineinfo_fh , $stream )
7970 or _db_warn("Cannot open '$stream' for write");
7971 $LINEINFO = $new_lineinfo_fh;
7972 _autoflush($LINEINFO);
7976 } ## end sub LineInfo
7978 =head1 COMMAND SUPPORT ROUTINES
7980 These subroutines provide functionality for various commands.
7982 =head2 C<list_modules>
7984 For the C<M> command: list modules loaded and their versions.
7985 Essentially just runs through the keys in %INC, picks each package's
7986 C<$VERSION> variable, gets the file name, and formats the information
7991 sub list_modules { # versions
7995 # keys are the "as-loaded" name, values are the fully-qualified path
7996 # to the file itself.
7998 $file = $_; # get the module name
7999 s,\.p[lm]$,,i; # remove '.pl' or '.pm'
8000 s,/,::,g; # change '/' to '::'
8001 s/^perl5db$/DB/; # Special case: debugger
8002 # moves to package DB
8003 s/^Term::ReadLine::readline$/readline/; # simplify readline
8005 # If the package has a $VERSION package global (as all good packages
8006 # should!) decode it and save as partial message.
8007 my $pkg_version = do { no strict 'refs'; ${ $_ . '::VERSION' } };
8008 if ( defined $pkg_version ) {
8009 $version{$file} = "$pkg_version from ";
8012 # Finish up the message with the file the package came from.
8013 $version{$file} .= $INC{$file};
8014 } ## end for (keys %INC)
8016 # Hey, dumpit() formats a hash nicely, so why not use it?
8017 dumpit( $OUT, \%version );
8018 } ## end sub list_modules
8022 Sets up the monster string used to format and print the help.
8024 =head3 HELP MESSAGE FORMAT
8026 The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments>
8027 (C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly
8028 easy to parse and portable, but which still allows the help to be a little
8029 nicer than just plain text.
8031 Essentially, you define the command name (usually marked up with C<< B<> >>
8032 and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a
8033 newline. The descriptive text can also be marked up in the same way. If you
8034 need to continue the descriptive text to another line, start that line with
8035 just tabs and then enter the marked-up text.
8037 If you are modifying the help text, I<be careful>. The help-string parser is
8038 not very sophisticated, and if you don't follow these rules it will mangle the
8039 help beyond hope until you fix the string.
8043 use vars qw($pre580_help);
8044 use vars qw($pre580_summary);
8048 # XXX: make sure there are tabs between the command and explanation,
8049 # or print_help will screw up your formatting if you have
8050 # eeevil ornaments enabled. This is an insane mess.
8053 Help is currently only available for the new 5.8 command set.
8054 No help is available for the old command set.
8055 We assume you know what you're doing if you switch to it.
8058 B<s> [I<expr>] Single step [in I<expr>].
8059 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
8060 <B<CR>> Repeat last B<n> or B<s> command.
8061 B<r> Return from current subroutine.
8062 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
8063 at the specified position.
8064 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
8065 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
8066 B<l> I<line> List single I<line>.
8067 B<l> I<subname> List first window of lines from subroutine.
8068 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
8069 B<l> List next window of lines.
8070 B<-> List previous window of lines.
8071 B<v> [I<line>] View window around I<line>.
8072 B<.> Return to the executed line.
8073 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
8074 I<filename> may be either the full name of the file, or a regular
8075 expression matching the full file name:
8076 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
8077 Evals (with saved bodies) are considered to be filenames:
8078 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
8079 (in the order of execution).
8080 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
8081 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
8082 B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions.
8083 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
8084 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth).
8085 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
8086 B<b> Sets breakpoint on current line)
8087 B<b> [I<line>] [I<condition>]
8088 Set breakpoint; I<line> defaults to the current execution line;
8089 I<condition> breaks if it evaluates to true, defaults to '1'.
8090 B<b> I<subname> [I<condition>]
8091 Set breakpoint at first line of subroutine.
8092 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
8093 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
8094 B<b> B<postpone> I<subname> [I<condition>]
8095 Set breakpoint at first line of subroutine after
8097 B<b> B<compile> I<subname>
8098 Stop after the subroutine is compiled.
8099 B<B> [I<line>] Delete the breakpoint for I<line>.
8100 B<B> I<*> Delete all breakpoints.
8101 B<a> [I<line>] I<command>
8102 Set an action to be done before the I<line> is executed;
8103 I<line> defaults to the current execution line.
8104 Sequence is: check for breakpoint/watchpoint, print line
8105 if necessary, do action, prompt user if necessary,
8108 B<A> [I<line>] Delete the action for I<line>.
8109 B<A> I<*> Delete all actions.
8110 B<w> I<expr> Add a global watch-expression.
8112 B<W> I<expr> Delete a global watch-expression.
8113 B<W> I<*> Delete all watch-expressions.
8114 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
8115 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
8116 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
8117 B<x> I<expr> Evals expression in list context, dumps the result.
8118 B<m> I<expr> Evals expression in list context, prints methods callable
8119 on the first element of the result.
8120 B<m> I<class> Prints methods callable via the given class.
8121 B<M> Show versions of loaded modules.
8122 B<i> I<class> Prints nested parents of given class.
8123 B<e> Display current thread id.
8124 B<E> Display all thread ids the current one will be identified: <n>.
8125 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8127 B<<> ? List Perl commands to run before each prompt.
8128 B<<> I<expr> Define Perl command to run before each prompt.
8129 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
8130 B<< *> Delete the list of perl commands to run before each prompt.
8131 B<>> ? List Perl commands to run after each prompt.
8132 B<>> I<expr> Define Perl command to run after each prompt.
8133 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
8134 B<>>B< *> Delete the list of Perl commands to run after each prompt.
8135 B<{> I<db_command> Define debugger command to run before each prompt.
8136 B<{> ? List debugger commands to run before each prompt.
8137 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
8138 B<{ *> Delete the list of debugger commands to run before each prompt.
8139 B<$prc> I<number> Redo a previous command (default previous command).
8140 B<$prc> I<-number> Redo number'th-to-last command.
8141 B<$prc> I<pattern> Redo last command that started with I<pattern>.
8142 See 'B<O> I<recallCommand>' too.
8143 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
8148 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
8150 See 'B<O> I<shellBang>' too.
8151 B<source> I<file> Execute I<file> containing debugger commands (may nest).
8152 B<save> I<file> Save current debugger session (actual history) to I<file>.
8153 B<rerun> Rerun session to current position.
8154 B<rerun> I<n> Rerun session to numbered command.
8155 B<rerun> I<-n> Rerun session to number'th-to-last command.
8156 B<H> I<-number> Display last number commands (default all).
8157 B<H> I<*> Delete complete history.
8158 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
8159 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
8160 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarily select()ed as well.
8161 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
8162 I<command> Execute as a perl statement in current package.
8163 B<R> Pure-man-restart of debugger, some of debugger state
8164 and command-line options may be lost.
8165 Currently the following settings are preserved:
8166 history, breakpoints and actions, debugger B<O>ptions
8167 and the following command-line options: I<-w>, I<-I>, I<-e>.
8169 B<o> [I<opt>] ... Set boolean option to true
8170 B<o> [I<opt>B<?>] Query options
8171 B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
8172 Set options. Use quotes if spaces in value.
8173 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
8174 I<pager> program for output of \"|cmd\";
8175 I<tkRunning> run Tk while prompting (with ReadLine);
8176 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
8177 I<inhibit_exit> Allows stepping off the end of the script.
8178 I<ImmediateStop> Debugger should stop as early as possible.
8179 I<RemotePort> Remote hostname:port for remote debugging
8180 The following options affect what happens with B<V>, B<X>, and B<x> commands:
8181 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
8182 I<compactDump>, I<veryCompact> change style of array and hash dump;
8183 I<globPrint> whether to print contents of globs;
8184 I<DumpDBFiles> dump arrays holding debugged files;
8185 I<DumpPackages> dump symbol tables of packages;
8186 I<DumpReused> dump contents of \"reused\" addresses;
8187 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
8188 I<bareStringify> Do not print the overload-stringified value;
8189 Other options include:
8190 I<PrintRet> affects printing of return value after B<r> command,
8191 I<frame> affects printing messages on subroutine entry/exit.
8192 I<AutoTrace> affects printing messages on possible breaking points.
8193 I<maxTraceLen> gives max length of evals/args listed in stack trace.
8194 I<ornaments> affects screen appearance of the command line.
8195 I<CreateTTY> bits control attempts to create a new TTY on events:
8196 1: on fork() 2: debugger is started inside debugger
8198 During startup options are initialized from \$ENV{PERLDB_OPTS}.
8199 You can put additional initialization options I<TTY>, I<noTTY>,
8200 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
8201 B<R> after you set them).
8203 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
8204 B<h> Summary of debugger commands.
8205 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
8206 B<h h> Long help for debugger commands
8207 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
8208 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
8209 Set B<\$DB::doccmd> to change viewer.
8211 Type '|h h' for a paged display if this was too hard to read.
8213 "; # Fix balance of vi % matching: }}}}
8215 # note: tabs in the following section are not-so-helpful
8216 $summary = <<"END_SUM";
8217 I<List/search source lines:> I<Control script execution:>
8218 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
8219 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
8220 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs
8221 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
8222 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
8223 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position
8224 I<Debugger controls:> B<L> List break/watch/actions
8225 B<o> [...] Set debugger options B<t> [I<n>] [I<expr>] Toggle trace [max depth] ][trace expr]
8226 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
8227 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints
8228 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
8229 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions
8230 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression
8231 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs
8232 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
8233 B<q> or B<^D> Quit B<R> Attempt a restart
8234 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
8235 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
8236 B<p> I<expr> Print expression (uses script's current package).
8237 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
8238 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
8239 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree.
8240 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8241 B<e> Display thread id B<E> Display all thread ids.
8242 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
8245 # ')}}; # Fix balance of vi % matching
8247 # and this is really numb...
8250 B<s> [I<expr>] Single step [in I<expr>].
8251 B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>].
8252 B<CR>> Repeat last B<n> or B<s> command.
8253 B<r> Return from current subroutine.
8254 B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint
8255 at the specified position.
8256 B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>.
8257 B<l> I<min>B<->I<max> List lines I<min> through I<max>.
8258 B<l> I<line> List single I<line>.
8259 B<l> I<subname> List first window of lines from subroutine.
8260 B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>.
8261 B<l> List next window of lines.
8262 B<-> List previous window of lines.
8263 B<w> [I<line>] List window around I<line>.
8264 B<.> Return to the executed line.
8265 B<f> I<filename> Switch to viewing I<filename>. File must be already loaded.
8266 I<filename> may be either the full name of the file, or a regular
8267 expression matching the full file name:
8268 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file.
8269 Evals (with saved bodies) are considered to be filenames:
8270 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval
8271 (in the order of execution).
8272 B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional.
8273 B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional.
8274 B<L> List all breakpoints and actions.
8275 B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>.
8276 B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth) .
8277 B<t> [I<n>] I<expr> Trace through execution of I<expr>.
8278 B<b> [I<line>] [I<condition>]
8279 Set breakpoint; I<line> defaults to the current execution line;
8280 I<condition> breaks if it evaluates to true, defaults to '1'.
8281 B<b> I<subname> [I<condition>]
8282 Set breakpoint at first line of subroutine.
8283 B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>.
8284 B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file.
8285 B<b> B<postpone> I<subname> [I<condition>]
8286 Set breakpoint at first line of subroutine after
8288 B<b> B<compile> I<subname>
8289 Stop after the subroutine is compiled.
8290 B<d> [I<line>] Delete the breakpoint for I<line>.
8291 B<D> Delete all breakpoints.
8292 B<a> [I<line>] I<command>
8293 Set an action to be done before the I<line> is executed;
8294 I<line> defaults to the current execution line.
8295 Sequence is: check for breakpoint/watchpoint, print line
8296 if necessary, do action, prompt user if necessary,
8298 B<a> [I<line>] Delete the action for I<line>.
8299 B<A> Delete all actions.
8300 B<W> I<expr> Add a global watch-expression.
8301 B<W> Delete all watch-expressions.
8302 B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current).
8303 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps.
8304 B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\".
8305 B<x> I<expr> Evals expression in list context, dumps the result.
8306 B<m> I<expr> Evals expression in list context, prints methods callable
8307 on the first element of the result.
8308 B<m> I<class> Prints methods callable via the given class.
8310 B<<> ? List Perl commands to run before each prompt.
8311 B<<> I<expr> Define Perl command to run before each prompt.
8312 B<<<> I<expr> Add to the list of Perl commands to run before each prompt.
8313 B<>> ? List Perl commands to run after each prompt.
8314 B<>> I<expr> Define Perl command to run after each prompt.
8315 B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt.
8316 B<{> I<db_command> Define debugger command to run before each prompt.
8317 B<{> ? List debugger commands to run before each prompt.
8318 B<{{> I<db_command> Add to the list of debugger commands to run before each prompt.
8319 B<$prc> I<number> Redo a previous command (default previous command).
8320 B<$prc> I<-number> Redo number'th-to-last command.
8321 B<$prc> I<pattern> Redo last command that started with I<pattern>.
8322 See 'B<O> I<recallCommand>' too.
8323 B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)"
8328 B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")."
8330 See 'B<O> I<shellBang>' too.
8331 B<source> I<file> Execute I<file> containing debugger commands (may nest).
8332 B<H> I<-number> Display last number commands (default all).
8333 B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package.
8334 B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager.
8335 B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well.
8336 B<\=> [I<alias> I<value>] Define a command alias, or list current aliases.
8337 I<command> Execute as a perl statement in current package.
8338 B<v> Show versions of loaded modules.
8339 B<R> Pure-man-restart of debugger, some of debugger state
8340 and command-line options may be lost.
8341 Currently the following settings are preserved:
8342 history, breakpoints and actions, debugger B<O>ptions
8343 and the following command-line options: I<-w>, I<-I>, I<-e>.
8345 B<O> [I<opt>] ... Set boolean option to true
8346 B<O> [I<opt>B<?>] Query options
8347 B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ...
8348 Set options. Use quotes if spaces in value.
8349 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell;
8350 I<pager> program for output of \"|cmd\";
8351 I<tkRunning> run Tk while prompting (with ReadLine);
8352 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity;
8353 I<inhibit_exit> Allows stepping off the end of the script.
8354 I<ImmediateStop> Debugger should stop as early as possible.
8355 I<RemotePort> Remote hostname:port for remote debugging
8356 The following options affect what happens with B<V>, B<X>, and B<x> commands:
8357 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all);
8358 I<compactDump>, I<veryCompact> change style of array and hash dump;
8359 I<globPrint> whether to print contents of globs;
8360 I<DumpDBFiles> dump arrays holding debugged files;
8361 I<DumpPackages> dump symbol tables of packages;
8362 I<DumpReused> dump contents of \"reused\" addresses;
8363 I<quote>, I<HighBit>, I<undefPrint> change style of string dump;
8364 I<bareStringify> Do not print the overload-stringified value;
8365 Other options include:
8366 I<PrintRet> affects printing of return value after B<r> command,
8367 I<frame> affects printing messages on subroutine entry/exit.
8368 I<AutoTrace> affects printing messages on possible breaking points.
8369 I<maxTraceLen> gives max length of evals/args listed in stack trace.
8370 I<ornaments> affects screen appearance of the command line.
8371 I<CreateTTY> bits control attempts to create a new TTY on events:
8372 1: on fork() 2: debugger is started inside debugger
8374 During startup options are initialized from \$ENV{PERLDB_OPTS}.
8375 You can put additional initialization options I<TTY>, I<noTTY>,
8376 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use
8377 B<R> after you set them).
8379 B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction.
8380 B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page.
8381 B<h h> Summary of debugger commands.
8382 B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the
8383 named Perl I<manpage>, or on B<$doccmd> itself if omitted.
8384 Set B<\$DB::doccmd> to change viewer.
8386 Type '|h' for a paged display if this was too hard to read.
8388 "; # Fix balance of vi % matching: }}}}
8390 # note: tabs in the following section are not-so-helpful
8391 $pre580_summary = <<"END_SUM";
8392 I<List/search source lines:> I<Control script execution:>
8393 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace
8394 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr]
8395 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs
8396 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s>
8397 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine
8398 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position
8399 I<Debugger controls:> B<L> List break/watch/actions
8400 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr]
8401 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint
8402 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints
8403 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line
8404 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression
8405 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch
8406 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess
8407 B<q> or B<^D> Quit B<R> Attempt a restart
8408 I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr>
8409 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods.
8410 B<p> I<expr> Print expression (uses script's current package).
8411 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern
8412 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern.
8413 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\".
8414 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>.
8415 For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs.
8418 # ')}}; # Fix balance of vi % matching
8420 } ## end sub sethelp
8422 =head2 C<print_help()>
8424 Most of what C<print_help> does is just text formatting. It finds the
8425 C<B> and C<I> ornaments, cleans them off, and substitutes the proper
8426 terminal control characters to simulate them (courtesy of
8427 C<Term::ReadLine::TermCap>).
8432 my $help_str = shift;
8434 # Restore proper alignment destroyed by eeevil I<> and B<>
8435 # ornaments: A pox on both their houses!
8437 # A help command will have everything up to and including
8438 # the first tab sequence padded into a field 16 (or if indented 20)
8439 # wide. If it's wider than that, an extra space will be added.
8441 ^ # only matters at start of line
8442 ( \ {4} | \t )* # some subcommands are indented
8443 ( < ? # so <CR> works
8444 [BI] < [^\t\n] + ) # find an eeevil ornament
8445 ( \t+ ) # original separation, discarded
8446 ( .* ) # this will now start (no earlier) than
8449 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4);
8450 my $clean = $command;
8451 $clean =~ s/[BI]<([^>]*)>/$1/g;
8453 # replace with this whole string:
8454 ($leadwhite ? " " x 4 : "")
8456 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ")
8461 $help_str =~ s{ # handle bold ornaments
8462 B < ( [^>] + | > ) >
8464 $Term::ReadLine::TermCap::rl_term_set[2]
8466 . $Term::ReadLine::TermCap::rl_term_set[3]
8469 $help_str =~ s{ # handle italic ornaments
8470 I < ( [^>] + | > ) >
8472 $Term::ReadLine::TermCap::rl_term_set[0]
8474 . $Term::ReadLine::TermCap::rl_term_set[1]
8478 print {$OUT} $help_str;
8481 } ## end sub print_help
8485 This routine does a lot of gyrations to be sure that the pager is C<less>.
8486 It checks for C<less> masquerading as C<more> and records the result in
8487 C<$fixed_less> so we don't have to go through doing the stats again.
8491 use vars qw($fixed_less);
8494 if ($pager =~ /\bless\b/)
8498 elsif ($pager =~ /\bmore\b/)
8500 # Nope, set to more. See what's out there.
8501 my @st_more = stat('/usr/bin/more');
8502 my @st_less = stat('/usr/bin/less');
8504 # is it really less, pretending to be more?
8508 && $st_more[0] == $st_less[0]
8509 && $st_more[1] == $st_less[1]
8519 # We already know if this is set.
8520 return if $fixed_less;
8522 # changes environment!
8523 # 'r' added so we don't do (slow) stats again.
8524 $fixed_less = 1 if _calc_is_less();
8527 } ## end sub fix_less
8529 =head1 DIE AND WARN MANAGEMENT
8533 C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying
8534 to debug a debugger problem.
8536 It does its best to report the error that occurred, and then forces the
8537 program, debugger, and everything to die.
8543 # No entry/exit messages.
8546 # No return value prints.
8549 # set the abort signal handling to the default (just terminate).
8550 $SIG{'ABRT'} = 'DEFAULT';
8552 # If we enter the signal handler recursively, kill myself with an
8553 # abort signal (so we just terminate).
8554 kill 'ABRT', $$ if $panic++;
8556 # If we can show detailed info, do so.
8557 if ( defined &Carp::longmess ) {
8559 # Don't recursively enter the warn handler, since we're carping.
8560 local $SIG{__WARN__} = '';
8562 # Skip two levels before reporting traceback: we're skipping
8563 # mydie and confess.
8564 local $Carp::CarpLevel = 2; # mydie + confess
8566 # Tell us all about it.
8567 _db_warn( Carp::longmess("Signal @_") );
8570 # No Carp. Tell us about the signal as best we can.
8573 print $DB::OUT "Got signal @_\n";
8578 } ## end sub diesignal
8582 The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to
8583 be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>.
8589 # No entry/exit trace.
8592 # No return value printing.
8595 # Turn off warn and die handling to prevent recursive entries to this
8597 local $SIG{__WARN__} = '';
8598 local $SIG{__DIE__} = '';
8600 # Load Carp if we can. If $^S is false (current thing being compiled isn't
8601 # done yet), we may not be able to do a require.
8602 eval { require Carp }
8603 if defined $^S; # If error/warning during compilation,
8604 # require may be broken.
8606 # Use the core warn() unless Carp loaded OK.
8608 "\nCannot print stack trace, load with -MCarp option to see stack" ),
8610 unless defined &Carp::longmess;
8612 # Save the current values of $single and $trace, and then turn them off.
8613 my ( $mysingle, $mytrace ) = ( $single, $trace );
8617 # We can call Carp::longmess without its being "debugged" (which we
8618 # don't want - we just want to use it!). Capture this for later.
8619 my $mess = Carp::longmess(@_);
8621 # Restore $single and $trace to their original values.
8622 ( $single, $trace ) = ( $mysingle, $mytrace );
8624 # Use the debugger's own special way of printing warnings to print
8625 # the stack trace message.
8631 The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace
8632 by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off
8633 single stepping and tracing during the call to C<Carp::longmess> to avoid
8634 debugging it - we just want to use it.
8636 If C<dieLevel> is zero, we let the program being debugged handle the
8637 exceptions. If it's 1, you get backtraces for any exception. If it's 2,
8638 the debugger takes over all exception handling, printing a backtrace and
8639 displaying the exception via its C<dbwarn()> routine.
8646 local $SIG{__DIE__} = '';
8647 local $SIG{__WARN__} = '';
8648 if ( $dieLevel > 2 ) {
8649 local $SIG{__WARN__} = \&dbwarn;
8650 _db_warn(@_); # Yell no matter what
8653 if ( $dieLevel < 2 ) {
8654 die @_ if $^S; # in eval propagate
8657 # The code used to check $^S to see if compilation of the current thing
8658 # hadn't finished. We don't do it anymore, figuring eval is pretty stable.
8659 eval { require Carp };
8662 "\nCannot print stack trace, load with -MCarp option to see stack" )
8663 unless defined &Carp::longmess;
8665 # We do not want to debug this chunk (automatic disabling works
8666 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off,
8667 # get the stack trace from Carp::longmess (if possible), restore $signal
8668 # and $trace, and then die with the stack trace.
8669 my ( $mysingle, $mytrace ) = ( $single, $trace );
8675 package Carp; # Do not include us in the list
8676 eval { $mess = Carp::longmess(@_); };
8678 ( $single, $trace ) = ( $mysingle, $mytrace );
8682 =head2 C<warnlevel()>
8684 Set the C<$DB::warnLevel> variable that stores the value of the
8685 C<warnLevel> option. Calling C<warnLevel()> with a positive value
8686 results in the debugger taking over all warning handlers. Setting
8687 C<warnLevel> to zero leaves any warning handlers set up by the program
8688 being debugged in place.
8694 my $prevwarn = $SIG{__WARN__} unless $warnLevel;
8697 $SIG{__WARN__} = \&DB::dbwarn;
8700 $SIG{__WARN__} = $prevwarn;
8702 undef $SIG{__WARN__};
8706 } ## end sub warnLevel
8710 Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the
8711 C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to
8712 zero lets you use your own C<die()> handler.
8719 my $prevdie = $SIG{__DIE__} unless $dieLevel;
8723 # Always set it to dbdie() for non-zero values.
8724 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2;
8726 # No longer exists, so don't try to use it.
8727 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2;
8729 # If we've finished initialization, mention that stack dumps
8730 # are enabled, If dieLevel is 1, we won't stack dump if we die
8732 print $OUT "Stack dump during die enabled",
8733 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n"
8736 # XXX This is probably obsolete, given that diehard() is gone.
8737 print $OUT "Dump printed too.\n" if $dieLevel > 2;
8738 } ## end if ($dieLevel)
8740 # Put the old one back if there was one.
8742 $SIG{__DIE__} = $prevdie;
8743 print $OUT "Default die handler restored.\n";
8745 undef $SIG{__DIE__};
8746 print $OUT "Die handler removed.\n";
8750 } ## end sub dieLevel
8752 =head2 C<signalLevel>
8754 Number three in a series: set C<signalLevel> to zero to keep your own
8755 signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger
8756 takes over and handles them with C<DB::diesignal()>.
8762 my $prevsegv = $SIG{SEGV} unless $signalLevel;
8763 my $prevbus = $SIG{BUS} unless $signalLevel;
8764 $signalLevel = shift;
8766 $SIG{SEGV} = \&DB::diesignal;
8767 $SIG{BUS} = \&DB::diesignal;
8770 $SIG{SEGV} = $prevsegv;
8771 $SIG{BUS} = $prevbus;
8775 } ## end sub signalLevel
8777 =head1 SUBROUTINE DECODING SUPPORT
8779 These subroutines are used during the C<x> and C<X> commands to try to
8780 produce as much information as possible about a code reference. They use
8781 L<Devel::Peek> to try to find the glob in which this code reference lives
8782 (if it does) - this allows us to actually code references which correspond
8783 to named subroutines (including those aliased via glob assignment).
8785 =head2 C<CvGV_name()>
8787 Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference
8788 via that routine. If this fails, return the reference again (when the
8789 reference is stringified, it'll come out as C<SOMETHING(0x...)>).
8795 my $name = CvGV_name_or_bust($in);
8796 defined $name ? $name : $in;
8799 =head2 C<CvGV_name_or_bust> I<coderef>
8801 Calls L<Devel::Peek> to try to find the glob the ref lives in; returns
8802 C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't
8803 find a glob for this ref.
8805 Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob.
8809 use vars qw($skipCvGV);
8811 sub CvGV_name_or_bust {
8813 return if $skipCvGV; # Backdoor to avoid problems if XS broken...
8814 return unless ref $in;
8815 $in = \&$in; # Hard reference...
8816 eval { require Devel::Peek; 1 } or return;
8817 my $gv = Devel::Peek::CvGV($in) or return;
8818 *$gv{PACKAGE} . '::' . *$gv{NAME};
8819 } ## end sub CvGV_name_or_bust
8823 A utility routine used in various places; finds the file where a subroutine
8824 was defined, and returns that filename and a line-number range.
8826 Tries to use C<@sub> first; if it can't find it there, it tries building a
8827 reference to the subroutine and uses C<CvGV_name_or_bust> to locate it,
8828 loading it into C<@sub> as a side effect (XXX I think). If it can't find it
8829 this way, it brute-force searches C<%sub>, checking for identical references.
8833 sub _find_sub_helper {
8836 return unless defined &$subr;
8837 my $name = CvGV_name_or_bust($subr);
8839 $data = $sub{$name} if defined $name;
8840 return $data if defined $data;
8843 $subr = \&$subr; # Hard reference
8846 $s = $_, last if $subr eq \&$_;
8861 return ( $sub{$subr} || _find_sub_helper($subr) );
8862 } ## end sub find_sub
8866 A subroutine that uses the utility function C<methods_via> to find all the
8867 methods in the class corresponding to the current reference and in
8876 # Figure out the class - either this is the class or it's a reference
8877 # to something blessed into that class.
8879 $class = ref $class if ref $class;
8883 # Show the methods that this class has.
8884 methods_via( $class, '', 1 );
8886 # Show the methods that UNIVERSAL has.
8887 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 );
8888 } ## end sub methods
8890 =head2 C<methods_via($class, $prefix, $crawl_upward)>
8892 C<methods_via> does the work of crawling up the C<@ISA> tree and reporting
8893 all the parent class methods. C<$class> is the name of the next class to
8894 try; C<$prefix> is the message prefix, which gets built up as we go up the
8895 C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go
8896 higher in the C<@ISA> tree, 0 if we should stop.
8902 # If we've processed this class already, just quit.
8904 return if $seen{$class}++;
8906 # This is a package that is contributing the methods we're about to print.
8908 my $prepend = $prefix ? "via $prefix: " : '';
8911 # Extract from all the symbols in this class.
8912 my $class_ref = do { no strict "refs"; \%{$class . '::'} };
8913 while (my ($name, $glob) = each %$class_ref) {
8914 # references directly in the symbol table are Proxy Constant
8915 # Subroutines, and are by their very nature defined
8916 # Otherwise, check if the thing is a typeglob, and if it is, it decays
8917 # to a subroutine reference, which can be tested by defined.
8918 # $glob might also be the value -1 (from sub foo;)
8919 # or (say) '$$' (from sub foo ($$);)
8920 # \$glob will be SCALAR in both cases.
8921 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob))
8922 && !$seen{$name}++) {
8923 push @to_print, "$prepend$name\n";
8930 print $DB::OUT $_ foreach sort @to_print;
8933 # If the $crawl_upward argument is false, just quit here.
8934 return unless shift;
8936 # $crawl_upward true: keep going up the tree.
8937 # Find all the classes this one is a subclass of.
8938 my $class_ISA_ref = do { no strict "refs"; \@{"${class}::ISA"} };
8939 for my $name ( @$class_ISA_ref ) {
8941 # Set up the new prefix.
8942 $prepend = $prefix ? $prefix . " -> $name" : $name;
8944 # Crawl up the tree and keep trying to crawl up.
8945 methods_via( $name, $prepend, 1 );
8947 } ## end sub methods_via
8949 =head2 C<setman> - figure out which command to use to show documentation
8951 Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly.
8956 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|NetWare)\z/s
8957 ? "man" # O Happy Day!
8958 : "perldoc"; # Alas, poor unfortunates
8961 =head2 C<runman> - run the appropriate command to show documentation
8963 Accepts a man page name; runs the appropriate command to display it (set up
8964 during debugger initialization). Uses C<_db_system()> to avoid mucking up the
8965 program's STDIN and STDOUT.
8972 _db_system("$doccmd $doccmd");
8976 # this way user can override, like with $doccmd="man -Mwhatever"
8977 # or even just "man " to disable the path check.
8978 if ( $doccmd ne 'man' ) {
8979 _db_system("$doccmd $page");
8983 $page = 'perl' if lc($page) eq 'help';
8986 my $man1dir = $Config::Config{man1direxp};
8987 my $man3dir = $Config::Config{man3direxp};
8988 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ }
8990 $manpath .= "$man1dir:" if $man1dir =~ /\S/;
8991 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir;
8992 chop $manpath if $manpath;
8994 # harmless if missing, I figure
8995 local $ENV{MANPATH} = $manpath if $manpath;
8996 my $nopathopt = $^O =~ /dunno what goes here/;
9001 # I just *know* there are men without -M
9002 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
9007 unless ( $page =~ /^perl\w/ ) {
9008 # Previously the debugger contained a list which it slurped in,
9009 # listing the known "perl" manpages. However, it was out of date,
9010 # with errors both of omission and inclusion. This approach is
9011 # considerably less complex. The failure mode on a butchered
9012 # install is simply that the user has to run man or perldoc
9013 # "manually" with the full manpage name.
9015 # There is a list of $^O values in installperl to determine whether
9016 # the directory is 'pods' or 'pod'. However, we can avoid tight
9017 # coupling to that by simply checking the "non-standard" 'pods'
9019 my $pods = "$Config::Config{privlibexp}/pods";
9020 $pods = "$Config::Config{privlibexp}/pod"
9022 if (-f "$pods/perl$page.pod") {
9023 CORE::system( $doccmd,
9024 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ),
9028 } ## end if (CORE::system($doccmd...
9031 #use Carp; # This did break, left for debugging
9033 =head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK
9035 Because of the way the debugger interface to the Perl core is designed, any
9036 debugger package globals that C<DB::sub()> requires have to be defined before
9037 any subroutines can be called. These are defined in the second C<BEGIN> block.
9039 This block sets things up so that (basically) the world is sane
9040 before the debugger starts executing. We set up various variables that the
9041 debugger has to have set up before the Perl core starts running:
9047 The debugger's own filehandles (copies of STD and STDOUT for now).
9051 Characters for shell escapes, the recall command, and the history command.
9055 The maximum recursion depth.
9059 The size of a C<w> command's window.
9063 The before-this-line context to be printed in a C<v> (view a window around this line) command.
9067 The fact that we're not in a sub at all right now.
9071 The default SIGINT handler for the debugger.
9075 The appropriate value of the flag in C<$^D> that says the debugger is running
9079 The current debugger recursion level
9083 The list of postponed items and the C<$single> stack (XXX define this)
9087 That we want no return values and no subroutine entry/exit trace.
9093 # The following BEGIN is very handy if debugger goes havoc, debugging debugger?
9095 use vars qw($db_stop);
9097 BEGIN { # This does not compile, alas. (XXX eh?)
9098 $IN = \*STDIN; # For bugs before DB::OUT has been opened
9099 $OUT = \*STDERR; # For errors before DB::OUT has been opened
9101 # Define characters used by command parsing.
9102 $sh = '!'; # Shell escape (does not work)
9103 $rc = ','; # Recall command (does not work)
9104 @hist = ('?'); # Show history (does not work)
9105 @truehist = (); # Can be saved for replay (per session)
9107 # This defines the point at which you get the 'deep recursion'
9108 # warning. It MUST be defined or the debugger will not load.
9111 # Number of lines around the current one that are shown in the
9115 # How much before-the-current-line context the 'v' command should
9116 # use in calculating the start of the window it will display.
9119 # We're not in any sub yet, but we need this to be a defined value.
9122 # Set up the debugger's interrupt handler. It simply sets a flag
9123 # ($signal) that DB::DB() will check before each command is executed.
9124 $SIG{INT} = \&DB::catch;
9126 # The following lines supposedly, if uncommented, allow the debugger to
9127 # debug itself. Perhaps we can try that someday.
9128 # This may be enabled to debug debugger:
9129 #$warnLevel = 1 unless defined $warnLevel;
9130 #$dieLevel = 1 unless defined $dieLevel;
9131 #$signalLevel = 1 unless defined $signalLevel;
9133 # This is the flag that says "a debugger is running, please call
9134 # DB::DB and DB::sub". We will turn it on forcibly before we try to
9135 # execute anything in the user's context, because we always want to
9137 $db_stop = 0; # Compiler warning ...
9138 $db_stop = 1 << 30; # ... because this is only used in an eval() later.
9140 # This variable records how many levels we're nested in debugging. Used
9141 # Used in the debugger prompt, and in determining whether it's all over or
9143 $level = 0; # Level of recursive debugging
9145 # "Triggers bug (?) in perl if we postpone this until runtime."
9146 # XXX No details on this yet, or whether we should fix the bug instead
9147 # of work around it. Stay tuned.
9150 # Used to track the current stack depth using the auto-stacked-variable
9152 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack
9154 # Don't print return values on exiting a subroutine.
9157 # No extry/exit tracing.
9162 BEGIN { $^W = $ini_warn; } # Switch warnings back
9164 =head1 READLINE SUPPORT - COMPLETION FUNCTION
9168 C<readline> support - adds command completion to basic C<readline>.
9170 Returns a list of possible completions to C<readline> when invoked. C<readline>
9171 will print the longest common substring following the text already entered.
9173 If there is only a single possible completion, C<readline> will use it in full.
9175 This code uses C<map> and C<grep> heavily to create lists of possible
9176 completion. Think LISP in this section.
9182 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah
9183 # $text is the text to be completed.
9184 # $line is the incoming line typed by the user.
9185 # $start is the start of the text to be completed in the incoming line.
9186 my ( $text, $line, $start ) = @_;
9188 # Save the initial text.
9189 # The search pattern is current package, ::, extract the next qualifier
9190 # Prefix and pack are set to undef.
9191 my ( $itext, $search, $prefix, $pack ) =
9192 ( $text, "^\Q${package}::\E([^:]+)\$" );
9194 =head3 C<b postpone|compile>
9200 Find all the subroutines that might match in this package
9204 Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself)
9208 Include all the rest of the subs that are known
9212 C<grep> out the ones that match the text we have so far
9216 Return this as the list of possible completions
9222 return sort grep /^\Q$text/, ( keys %sub ),
9223 qw(postpone load compile), # subroutines
9224 ( map { /$search/ ? ($1) : () } keys %sub )
9225 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/;
9229 Get all the possible files from C<@INC> as it currently stands and
9230 select the ones that match the text so far.
9234 return sort grep /^\Q$text/, values %INC # files
9235 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/;
9237 =head3 C<V> (list variable) and C<m> (list modules)
9239 There are two entry points for these commands:
9241 =head4 Unqualified package names
9243 Get the top-level packages and grab everything that matches the text
9244 so far. For each match, recursively complete the partial packages to
9245 get all possible matching packages. Return this sorted list.
9249 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9250 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages
9251 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/;
9253 =head4 Qualified package names
9255 Take a partially-qualified package and find all subpackages for it
9256 by getting all the subpackages for the package so far, matching all
9257 the subpackages against the text, and discarding all of them which
9258 start with 'main::'. Return this list.
9262 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) }
9263 grep !/^main::/, grep /^\Q$text/,
9264 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () }
9265 do { no strict 'refs'; keys %{ $prefix . '::' } }
9266 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/
9267 and $text =~ /^(.*[^:])::?(\w*)$/
9270 =head3 C<f> - switch files
9272 Here, we want to get a fully-qualified filename for the C<f> command.
9277 =item 1. The original source file itself
9279 =item 2. A file from C<@INC>
9281 =item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>).
9287 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files
9288 # We might possibly want to switch to an eval (which has a "filename"
9289 # like '(eval 9)'), so we may need to clean up the completion text
9290 # before proceeding.
9291 $prefix = length($1) - length($text);
9296 Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file>
9297 (C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these
9298 out of C<%main::>, add the initial source file, and extract the ones that
9299 match the completion text so far.
9304 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ),
9306 } ## end if ($line =~ /^\|*f\s+(.*)/)
9308 =head3 Subroutine name completion
9310 We look through all of the defined subs (the keys of C<%sub>) and
9311 return both all the possible matches to the subroutine name plus
9312 all the matches qualified to the current package.
9316 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines
9317 $text = substr $text, 1;
9319 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ),
9321 map { /$search/ ? ($1) : () }
9324 } ## end if ((substr $text, 0, ...
9326 =head3 Scalar, array, and hash completion: partially qualified package
9328 Much like the above, except we have to do a little more cleanup:
9332 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package
9340 Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified.
9344 $pack = ( $1 eq 'main' ? '' : $1 ) . '::';
9350 Figure out the prefix vs. what needs completing.
9354 $prefix = ( substr $text, 0, 1 ) . $1 . '::';
9361 Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities.
9367 map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/,
9375 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.
9379 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9380 return db_complete( $out[0], $line, $start );
9383 # Return the list of possibles.
9386 } ## end if ($text =~ /^[\$@%](.*)::(.*)/)
9392 =head3 Symbol completion: current package or package C<main>.
9396 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main)
9403 If it's C<main>, delete main to just get C<::> leading.
9407 $pack = ( $package eq 'main' ? '' : $package ) . '::';
9413 We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed.
9417 $prefix = substr $text, 0, 1;
9418 $text = substr $text, 1;
9426 We look for the lexical scope above DB::DB and auto-complete lexical variables
9427 if PadWalker could be loaded.
9431 if (not $text =~ /::/ and eval { require PadWalker } ) {
9434 my @info = caller($level);
9438 last if $info[3] eq 'DB::DB';
9441 my $lexicals = PadWalker::peek_my($level);
9442 push @out, grep /^\Q$prefix$text/, keys %$lexicals;
9450 If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols.
9454 push @out, map "$prefix$_", grep /^\Q$text/,
9455 ( grep /^_?[a-zA-Z]/, do { no strict 'refs'; keys %$pack } ),
9456 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) );
9460 If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol.
9466 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) {
9467 return db_complete( $out[0], $line, $start );
9470 # Return the list of possibles.
9472 } ## end if ($text =~ /^[\$@%]/)
9476 We use C<option_val()> to look up the current value of the option. If there's
9477 only a single value, we complete the command in such a way that it is a
9478 complete command for setting the option in question. If there are multiple
9479 possible values, we generate a command consisting of the option plus a trailing
9480 question mark, which, if executed, will list the current value of the option.
9484 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ )
9485 { # Options after space
9486 # We look for the text to be matched in the list of possible options,
9487 # and fetch the current value.
9488 my @out = grep /^\Q$text/, @options;
9489 my $val = option_val( $out[0], undef );
9491 # Set up a 'query option's value' command.
9493 if ( not defined $val or $val =~ /[\n\r]/ ) {
9495 # There's really nothing else we can do.
9498 # We have a value. Create a proper option-setting command.
9499 elsif ( $val =~ /\s/ ) {
9501 # XXX This may be an extraneous variable.
9504 # We'll want to quote the string (because of the embedded
9505 # whtespace), but we want to make sure we don't end up with
9506 # mismatched quote characters. We try several possibilities.
9507 foreach my $l ( split //, qq/\"\'\#\|/ ) {
9509 # If we didn't find this quote character in the value,
9510 # quote it using this quote character.
9511 $out = "$l$val$l ", last if ( index $val, $l ) == -1;
9513 } ## end elsif ($val =~ /\s/)
9515 # Don't need any quotes.
9520 # If there were multiple possible values, return '? ', which
9521 # makes the command into a query command. If there was just one,
9522 # have readline append that.
9523 $rl_attribs->{completer_terminator_character} =
9524 ( @out == 1 ? $out : '? ' );
9526 # Return list of possibilities.
9528 } ## end if ((substr $line, 0, ...
9530 =head3 Filename completion
9532 For entering filenames. We simply call C<readline>'s C<filename_list()>
9533 method with the completion text to get the possible completions.
9537 return $term->filename_list($text); # filenames
9539 } ## end sub db_complete
9541 =head1 MISCELLANEOUS SUPPORT FUNCTIONS
9543 Functions that possibly ought to be somewhere else.
9553 print $OUT "Use 'q' to quit or 'R' to restart. 'h q' for details.\n";
9558 If we have $ini_pids, save it in the environment; else remove it from the
9559 environment. Used by the C<R> (restart) command.
9564 if ( defined($ini_pids) ) {
9565 $ENV{PERLDB_PIDS} = $ini_pids;
9568 delete( $ENV{PERLDB_PIDS} );
9570 } ## end sub clean_ENV
9572 # PERLDBf_... flag names from perl.h
9573 our ( %DollarCaretP_flags, %DollarCaretP_flags_r );
9576 %DollarCaretP_flags = (
9577 PERLDBf_SUB => 0x01, # Debug sub enter/exit
9578 PERLDBf_LINE => 0x02, # Keep line #
9579 PERLDBf_NOOPT => 0x04, # Switch off optimizations
9580 PERLDBf_INTER => 0x08, # Preserve more data
9581 PERLDBf_SUBLINE => 0x10, # Keep subr source lines
9582 PERLDBf_SINGLE => 0x20, # Start with single-step on
9583 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr
9584 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto
9585 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals
9586 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs
9587 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"}
9588 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO
9590 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger
9591 # doesn't need to set it. It's provided for the benefit of profilers and
9592 # other code analysers.
9594 %DollarCaretP_flags_r = reverse %DollarCaretP_flags;
9597 sub parse_DollarCaretP_flags {
9602 foreach my $f ( split /\s*\|\s*/, $flags ) {
9604 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) {
9607 elsif ( $f =~ /^(\d+)$/ ) {
9610 elsif ( $f =~ /^DEFAULT$/i ) {
9611 $value = $DollarCaretP_flags{PERLDB_ALL};
9614 $f =~ /^(?:PERLDBf_)?(.*)$/i;
9615 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) };
9616 unless ( defined $value ) {
9618 "Unrecognized \$^P flag '$f'!\n",
9619 "Acceptable flags are: "
9620 . join( ', ', sort keys %DollarCaretP_flags ),
9621 ", and hexadecimal and decimal numbers.\n"
9631 sub expand_DollarCaretP_flags {
9632 my $DollarCaretP = shift;
9635 my $n = ( 1 << $_ );
9636 ( $DollarCaretP & $n )
9637 ? ( $DollarCaretP_flags_r{$n}
9638 || sprintf( '0x%x', $n ) )
9642 return @bits ? join( '|', @bits ) : 0;
9649 Rerun the current session to:
9651 rerun current position
9653 rerun 4 command number 4
9655 rerun -4 current command minus 4 (go back 4 steps)
9657 Whether this always makes sense, in the current context is unknowable, and is
9658 in part left as a useful exercise for the reader. This sub returns the
9659 appropriate arguments to rerun the current session.
9666 pop(@truehist); # strim
9667 unless (defined $truehist[$i]) {
9668 print "Unable to return to non-existent command: $i\n";
9670 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist);
9671 my @temp = @truehist; # store
9672 push(@DB::typeahead, @truehist); # saved
9673 @truehist = @hist = (); # flush
9674 @args = restart(); # setup
9675 get_list("PERLDB_HIST"); # clean
9676 set_list("PERLDB_HIST", @temp); # reset
9683 Restarting the debugger is a complex operation that occurs in several phases.
9684 First, we try to reconstruct the command line that was used to invoke Perl
9690 # I may not be able to resurrect you, but here goes ...
9692 "Warning: some settings and command-line options may be lost!\n";
9693 my ( @script, @flags, $cl );
9695 # If warn was on before, turn it on again.
9696 push @flags, '-w' if $ini_warn;
9698 # Rebuild the -I flags that were on the initial
9701 push @flags, '-I', $_;
9704 # Turn on taint if it was on before.
9705 push @flags, '-T' if ${^TAINT};
9707 # Arrange for setting the old INC:
9708 # Save the current @init_INC in the environment.
9709 set_list( "PERLDB_INC", @ini_INC );
9711 # If this was a perl one-liner, go to the "file"
9712 # corresponding to the one-liner read all the lines
9713 # out of it (except for the first one, which is going
9714 # to be added back on again when 'perl -d' runs: that's
9715 # the 'require perl5db.pl;' line), and add them back on
9716 # to the command line to be executed.
9718 my $lines = *{$main::{'_<-e'}}{ARRAY};
9719 for ( 1 .. $#$lines ) { # The first line is PERL5DB
9720 chomp( $cl = $lines->[$_] );
9721 push @script, '-e', $cl;
9723 } ## end if ($0 eq '-e')
9725 # Otherwise we just reuse the original name we had
9733 After the command line has been reconstructed, the next step is to save
9734 the debugger's status in environment variables. The C<DB::set_list> routine
9735 is used to save aggregate variables (both hashes and arrays); scalars are
9736 just popped into environment variables directly.
9740 # If the terminal supported history, grab it and
9741 # save that in the environment.
9742 set_list( "PERLDB_HIST",
9743 $term->Features->{getHistory}
9747 # Find all the files that were visited during this
9748 # session (i.e., the debugger had magic hashes
9749 # corresponding to them) and stick them in the environment.
9750 my @had_breakpoints = keys %had_breakpoints;
9751 set_list( "PERLDB_VISITED", @had_breakpoints );
9753 # Save the debugger options we chose.
9754 set_list( "PERLDB_OPT", %option );
9755 # set_list( "PERLDB_OPT", options2remember() );
9757 # Save the break-on-loads.
9758 set_list( "PERLDB_ON_LOAD", %break_on_load );
9762 The most complex part of this is the saving of all of the breakpoints. They
9763 can live in an awful lot of places, and we have to go through all of them,
9764 find the breakpoints, and then save them in the appropriate environment
9765 variable via C<DB::set_list>.
9769 # Go through all the breakpoints and make sure they're
9772 for ( 0 .. $#had_breakpoints ) {
9774 # We were in this file.
9775 my $file = $had_breakpoints[$_];
9777 # Grab that file's magic line hash.
9778 *dbline = $main::{ '_<' . $file };
9780 # Skip out if it doesn't exist, or if the breakpoint
9781 # is in a postponed file (we'll do postponed ones
9783 next unless %dbline or $postponed_file{$file};
9785 # In an eval. This is a little harder, so we'll
9786 # do more processing on that below.
9787 ( push @hard, $file ), next
9788 if $file =~ /^\(\w*eval/;
9790 # XXX I have no idea what this is doing. Yet.
9792 @add = %{ $postponed_file{$file} }
9793 if $postponed_file{$file};
9795 # Save the list of all the breakpoints for this file.
9796 set_list( "PERLDB_FILE_$_", %dbline, @add );
9798 # Serialize the extra data %breakpoints_data hash.
9800 set_list( "PERLDB_FILE_ENABLED_$_",
9801 map { _is_breakpoint_enabled($file, $_) ? 1 : 0 }
9802 sort { $a <=> $b } keys(%dbline)
9804 } ## end for (0 .. $#had_breakpoints)
9806 # The breakpoint was inside an eval. This is a little
9807 # more difficult. XXX and I don't understand it.
9808 foreach my $hard_file (@hard) {
9809 # Get over to the eval in question.
9810 *dbline = $main::{ '_<' . $hard_file };
9811 my $quoted = quotemeta $hard_file;
9813 for my $sub ( keys %sub ) {
9814 if (my ($n1, $n2) = $sub{$sub} =~ /\A$quoted:(\d+)-(\d+)\z/) {
9815 $subs{$sub} = [ $n1, $n2 ];
9820 "No subroutines in $hard_file, ignoring breakpoints.\n";
9823 LINES: foreach my $line ( keys %dbline ) {
9825 # One breakpoint per sub only:
9826 my ( $offset, $found );
9827 SUBS: foreach my $sub ( keys %subs ) {
9829 $subs{$sub}->[1] >= $line # Not after the subroutine
9831 not defined $offset # Not caught
9837 $offset = $line - $subs{$sub}->[0];
9839 $offset = "+$offset";
9842 } ## end if ($subs{$sub}->[1] >=...
9843 } ## end for $sub (keys %subs)
9844 if ( defined $offset ) {
9845 $postponed{$found} =
9846 "break $offset if $dbline{$line}";
9850 ("Breakpoint in ${hard_file}:$line ignored:"
9851 . " after all the subroutines.\n");
9853 } ## end for $line (keys %dbline)
9854 } ## end for (@hard)
9856 # Save the other things that don't need to be
9858 set_list( "PERLDB_POSTPONE", %postponed );
9859 set_list( "PERLDB_PRETYPE", @$pretype );
9860 set_list( "PERLDB_PRE", @$pre );
9861 set_list( "PERLDB_POST", @$post );
9862 set_list( "PERLDB_TYPEAHEAD", @typeahead );
9864 # We are officially restarting.
9865 $ENV{PERLDB_RESTART} = 1;
9867 # We are junking all child debuggers.
9868 delete $ENV{PERLDB_PIDS}; # Restore ini state
9870 # Set this back to the initial pid.
9871 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids;
9875 After all the debugger status has been saved, we take the command we built up
9876 and then return it, so we can C<exec()> it. The debugger will spot the
9877 C<PERLDB_RESTART> environment variable and realize it needs to reload its state
9878 from the environment.
9882 # And run Perl again. Add the "-d" flag, all the
9883 # flags we built up, the script (whether a one-liner
9884 # or a file), add on the -emacs flag for a slave editor,
9885 # and then the old arguments.
9887 return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS);
9893 =head1 END PROCESSING - THE C<END> BLOCK
9895 Come here at the very end of processing. We want to go into a
9896 loop where we allow the user to enter commands and interact with the
9897 debugger, but we don't want anything else to execute.
9899 First we set the C<$finished> variable, so that some commands that
9900 shouldn't be run after the end of program quit working.
9902 We then figure out whether we're truly done (as in the user entered a C<q>
9903 command, or we finished execution while running nonstop). If we aren't,
9904 we set C<$single> to 1 (causing the debugger to get control again).
9906 We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...>
9907 message and returns control to the debugger. Repeat.
9909 When the user finally enters a C<q> command, C<$fall_off_end> is set to
9910 1 and the C<END> block simply exits with C<$single> set to 0 (don't
9911 break, run to completion.).
9916 $finished = 1 if $inhibit_exit; # So that some commands may be disabled.
9917 $fall_off_end = 1 unless $inhibit_exit;
9919 # Do not stop in at_exit() and destructors on exit:
9920 if ($fall_off_end or $runnonstop) {
9924 DB::fake::at_exit();
9928 =head1 PRE-5.8 COMMANDS
9930 Some of the commands changed function quite a bit in the 5.8 command
9931 realignment, so much so that the old code had to be replaced completely.
9932 Because we wanted to retain the option of being able to go back to the
9933 former command set, we moved the old code off to this section.
9935 There's an awful lot of duplicated code here. We've duplicated the
9936 comments to keep things clear.
9940 Does nothing. Used to I<turn off> commands.
9944 sub cmd_pre580_null {
9949 =head2 Old C<a> command.
9951 This version added actions if you supplied them, and deleted them
9960 # Argument supplied. Add the action.
9961 if ( $cmd =~ /^(\d*)\s*(.*)/ ) {
9963 # If the line isn't there, use the current line.
9964 my $i = $1 || $line;
9967 # If there is an action ...
9970 # ... but the line isn't breakable, skip it.
9971 if ( $dbline[$i] == 0 ) {
9972 print $OUT "Line $i may not have an action.\n";
9976 # ... and the line is breakable:
9977 # Mark that there's an action in this file.
9978 $had_breakpoints{$filename} |= 2;
9980 # Delete any current action.
9981 $dbline{$i} =~ s/\0[^\0]*//;
9983 # Add the new action, continuing the line as needed.
9984 $dbline{$i} .= "\0" . action($j);
9986 } ## end if (length $j)
9988 # No action supplied.
9991 # Delete the action.
9992 $dbline{$i} =~ s/\0[^\0]*//;
9994 # Mark as having no break or action if nothing's left.
9995 delete $dbline{$i} if $dbline{$i} eq '';
9997 } ## end if ($cmd =~ /^(\d*)\s*(.*)/)
9998 } ## end sub cmd_pre580_a
10000 =head2 Old C<b> command
10009 my $dbline = shift;
10012 if ( $cmd =~ /^load\b\s*(.*)/ ) {
10018 # b compile|postpone <some sub> [<condition>]
10019 # The interpreter actually traps this one for us; we just put the
10020 # necessary condition in the %postponed hash.
10021 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) {
10023 # Capture the condition if there is one. Make it true if none.
10024 my $cond = length $3 ? $3 : '1';
10026 # Save the sub name and set $break to 1 if $1 was 'postpone', 0
10027 # if it was 'compile'.
10028 my ( $subname, $break ) = ( $2, $1 eq 'postpone' );
10030 # De-Perl4-ify the name - ' separators to ::.
10031 $subname =~ s/\'/::/g;
10033 # Qualify it into the current package unless it's already qualified.
10034 $subname = "${package}::" . $subname
10035 unless $subname =~ /::/;
10037 # Add main if it starts with ::.
10038 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::";
10040 # Save the break type for this sub.
10041 $postponed{$subname} = $break ? "break +0 if $cond" : "compile";
10042 } ## end elsif ($cmd =~ ...
10044 # b <sub name> [<condition>]
10045 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) {
10047 my $cond = length $2 ? $2 : '1';
10048 cmd_b_sub( $subname, $cond );
10050 # b <line> [<condition>].
10051 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) {
10052 my $i = $1 || $dbline;
10053 my $cond = length $2 ? $2 : '1';
10054 cmd_b_line( $i, $cond );
10056 } ## end sub cmd_pre580_b
10058 =head2 Old C<D> command.
10060 Delete all breakpoints unconditionally.
10067 if ( $cmd =~ /^\s*$/ ) {
10068 print $OUT "Deleting all breakpoints...\n";
10070 # %had_breakpoints lists every file that had at least one
10071 # breakpoint in it.
10073 for $file ( keys %had_breakpoints ) {
10075 # Switch to the desired file temporarily.
10076 local *dbline = $main::{ '_<' . $file };
10081 # For all lines in this file ...
10082 for my $i (1 .. $max) {
10084 # If there's a breakpoint or action on this line ...
10085 if ( defined $dbline{$i} ) {
10087 # ... remove the breakpoint.
10088 $dbline{$i} =~ s/^[^\0]+//;
10089 if ( $dbline{$i} =~ s/^\0?$// ) {
10091 # Remove the entry altogether if no action is there.
10092 delete $dbline{$i};
10094 } ## end if (defined $dbline{$i...
10095 } ## end for my $i (1 .. $max)
10097 # If, after we turn off the "there were breakpoints in this file"
10098 # bit, the entry in %had_breakpoints for this file is zero,
10099 # we should remove this file from the hash.
10100 if ( not $had_breakpoints{$file} &= ~1 ) {
10101 delete $had_breakpoints{$file};
10103 } ## end for $file (keys %had_breakpoints)
10105 # Kill off all the other breakpoints that are waiting for files that
10106 # haven't been loaded yet.
10108 undef %postponed_file;
10109 undef %break_on_load;
10110 } ## end if ($cmd =~ /^\s*$/)
10111 } ## end sub cmd_pre580_D
10113 =head2 Old C<h> command
10115 Print help. Defaults to printing the long-form help; the 5.8 version
10116 prints the summary by default.
10124 # Print the *right* help, long format.
10125 if ( $cmd =~ /^\s*$/ ) {
10126 print_help($pre580_help);
10129 # 'h h' - explicitly-requested summary.
10130 elsif ( $cmd =~ /^h\s*/ ) {
10131 print_help($pre580_summary);
10134 # Find and print a command's help.
10135 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) {
10136 my $asked = $1; # for proper errmsg
10137 my $qasked = quotemeta($asked); # for searching
10138 # XXX: finds CR but not <CR>
10142 (?:[IB]<) # Optional markup
10143 $qasked # The command name
10150 ( # The command help:
10152 (?:[IB]<) # Optional markup
10153 $qasked # The command name
10154 ([\s\S]*?) # Lines starting with tabs
10158 ) # Line not starting with space
10159 # (Next command's help)
10163 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m)
10167 print_help("B<$asked> is not a debugger command.\n");
10169 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/)
10170 } ## end sub cmd_pre580_h
10172 =head2 Old C<W> command
10174 C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all.
10182 # Delete all watch expressions.
10183 if ( $cmd =~ /^$/ ) {
10185 # No watching is going on.
10188 # Kill all the watch expressions and values.
10189 @to_watch = @old_watch = ();
10192 # Add a watch expression.
10193 elsif ( $cmd =~ /^(.*)/s ) {
10195 # add it to the list to be watched.
10196 push @to_watch, $1;
10198 # Get the current value of the expression.
10199 # Doesn't handle expressions returning list values!
10201 # The &-call is here to ascertain the mutability of @_.
10202 my ($val) = &DB::eval;
10203 $val = ( defined $val ) ? "'$val'" : 'undef';
10206 push @old_watch, $val;
10208 # We're watching stuff.
10211 } ## end elsif ($cmd =~ /^(.*)/s)
10212 } ## end sub cmd_pre580_W
10214 =head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS
10216 The debugger used to have a bunch of nearly-identical code to handle
10217 the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and
10218 C<cmd_prepost> unify all this into one set of code to handle the
10219 appropriate actions.
10221 =head2 C<cmd_pre590_prepost>
10223 A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't
10224 do something destructive. In pre 5.8 debuggers, the default action was to
10225 delete all the actions.
10229 sub cmd_pre590_prepost {
10231 my $line = shift || '*';
10232 my $dbline = shift;
10234 return cmd_prepost( $cmd, $line, $dbline );
10235 } ## end sub cmd_pre590_prepost
10237 =head2 C<cmd_prepost>
10239 Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc.
10240 Since the lists of actions are all held in arrays that are pointed to by
10241 references anyway, all we have to do is pick the right array reference and
10242 then use generic code to all, delete, or list actions.
10249 # No action supplied defaults to 'list'.
10250 my $line = shift || '?';
10252 # Figure out what to put in the prompt.
10255 # Make sure we have some array or another to address later.
10256 # This means that if for some reason the tests fail, we won't be
10257 # trying to stash actions or delete them from the wrong place.
10260 # < - Perl code to run before prompt.
10261 if ( $cmd =~ /^\</o ) {
10262 $which = 'pre-perl';
10266 # > - Perl code to run after prompt.
10267 elsif ( $cmd =~ /^\>/o ) {
10268 $which = 'post-perl';
10272 # { - first check for properly-balanced braces.
10273 elsif ( $cmd =~ /^\{/o ) {
10274 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) {
10276 "$cmd is now a debugger command\nuse ';$cmd' if you mean Perl code\n";
10279 # Properly balanced. Pre-prompt debugger actions.
10281 $which = 'pre-debugger';
10284 } ## end elsif ( $cmd =~ /^\{/o )
10286 # Did we find something that makes sense?
10288 print $OUT "Confused by command: $cmd\n";
10295 if ( $line =~ /^\s*\?\s*$/o ) {
10298 # Nothing there. Complain.
10299 print $OUT "No $which actions.\n";
10303 # List the actions in the selected list.
10304 print $OUT "$which commands:\n";
10305 foreach my $action (@$aref) {
10306 print $OUT "\t$cmd -- $action\n";
10309 } ## end if ( $line =~ /^\s*\?\s*$/o)
10311 # Might be a delete.
10313 if ( length($cmd) == 1 ) {
10314 if ( $line =~ /^\s*\*\s*$/o ) {
10316 # It's a delete. Get rid of the old actions in the
10319 print $OUT "All $cmd actions cleared.\n";
10323 # Replace all the actions. (This is a <, >, or {).
10324 @$aref = action($line);
10326 } ## end if ( length($cmd) == 1)
10327 elsif ( length($cmd) == 2 ) {
10329 # Add the action to the line. (This is a <<, >>, or {{).
10330 push @$aref, action($line);
10334 # <<<, >>>>, {{{{{{ ... something not a command.
10336 "Confused by strange length of $which command($cmd)...\n";
10338 } ## end else [ if ( $line =~ /^\s*\?\s*$/o)
10340 } ## end sub cmd_prepost
10344 Contains the C<at_exit> routine that the debugger uses to issue the
10345 C<Debugged program terminated ...> message after the program completes. See
10346 the C<END> block documentation for more details.
10353 "Debugged program terminated. Use 'q' to quit or 'R' to restart.";
10356 package DB; # Do not trace this 1; below!