(C<eval>'d) as Perl code in the current package. (The debugger
uses the DB package for keeping its own state information.)
+Note that the said C<eval> is bound by an implicit scope. As a
+result any newly introduced lexical variable or any modified
+capture buffer content is lost after the eval. The debugger is a
+nice environment to learn Perl, but if you interactively experiment using
+material which should be in the same scope, stuff it in one line.
+
For any text entered at the debugger prompt, leading and trailing whitespace
is first stripped before further processing. If a debugger command
coincides with some function in your own program, merely precede the
=over 12
+=item h
+
+Prints out a summary help message
+
=item h [command]
-Prints out a help message.
+Prints out a help message for the given debugger command.
-If you supply another debugger command as an argument to the C<h> command,
-it prints out the description for just that command. The special
-argument of C<h h> produces a more compact help listing, designed to fit
-together on one screen.
+=item h h
-If the output of the C<h> command (or any command, for that matter) scrolls
+The special argument of C<h h> produces the entire help page, which is quite long.
+
+If the output of the C<h h> command (or any command, for that matter) scrolls
past your screen, precede the command with a leading pipe symbol so
that it's run through your pager, as in
- DB> |h
+ DB> |h h
+
+You may change the pager which is used via C<o pager=...> command.
-You may change the pager which is used via C<O pager=...> command.
=item p expr
The C<DB::OUT> filehandle is opened to F</dev/tty>, regardless of
where STDOUT may be redirected to.
-=item x expr
+=item x [maxdepth] expr
-Evaluates its expression in list context and dumps out the result
-in a pretty-printed fashion. Nested data structures are printed out
-recursively, unlike the real C<print> function in Perl.
+Evaluates its expression in list context and dumps out the result in a
+pretty-printed fashion. Nested data structures are printed out
+recursively, unlike the real C<print> function in Perl. When dumping
+hashes, you'll probably prefer 'x \%h' rather than 'x %h'.
See L<Dumpvalue> if you'd like to do this yourself.
The output format is governed by multiple options described under
L<"Configurable Options">.
+If the C<maxdepth> is included, it must be a numeral I<N>; the value is
+dumped only I<N> levels deep, as if the C<dumpDepth> option had been
+temporarily set to I<N>.
+
=item V [pkg [vars]]
-Display all (or some) variables in package (defaulting to C<main>)
+Display all (or some) variables in package (defaulting to C<main>)
using a data pretty-printer (hashes show their keys and values so
you see what's what, control characters are made printable, etc.).
Make sure you don't put the type specifier (like C<$>) there, just
Same as C<V currentpackage [vars]>.
+=item y [level [vars]]
+
+Display all (or some) lexical variables (mnemonic: C<mY> variables)
+in the current scope or I<level> scopes higher. You can limit the
+variables that you see with I<vars> which works exactly as it does
+for the C<V> and C<X> commands. Requires the C<PadWalker> module
+version 0.08 or higher; will warn if this isn't installed. Output
+is pretty-printed in the same style as for C<V> and the format is
+controlled by the same options.
+
=item T
Produce a stack backtrace. See below for details on its output.
List previous window of lines.
-=item w [line]
+=item v [line]
-List window (a few lines) around the current line.
+View a few lines of code around the current line.
=item .
=item f filename
Switch to viewing a different file or C<eval> statement. If I<filename>
-is not a full pathname found in the values of %INC, it is considered
+is not a full pathname found in the values of %INC, it is considered
a regex.
C<eval>ed strings (when accessible) are considered to be filenames:
Search backwards for pattern; final ? is optional.
The search is case-insensitive by default.
-=item L
+=item L [abw]
-List all breakpoints and actions.
+List (default all) actions, breakpoints and watch expressions
=item S [[!]regex]
Trace through execution of C<expr>.
See L<perldebguts/"Frame Listing Output Examples"> for examples.
+=item b
+
+Sets breakpoint on current line
+
=item b [line] [condition]
-Set a breakpoint before the given line. If I<line> is omitted, set a
-breakpoint on the line about to be executed. If a condition
+Set a breakpoint before the given line. If a condition
is specified, it's evaluated each time the statement is reached: a
breakpoint is taken only if the condition is true. Breakpoints may
only be set on lines that begin an executable statement. Conditions
Sets a breakpoint before the first statement executed after the specified
subroutine is compiled.
-=item d [line]
+=item B line
-Delete a breakpoint from the specified I<line>. If I<line> is omitted, deletes
-the breakpoint from the line about to be executed.
+Delete a breakpoint from the specified I<line>.
-=item D
+=item B *
Delete all installed breakpoints.
a 53 print "DB FOUND $foo\n"
-=item a [line]
+=item A line
-Delete an action from the specified line. If I<line> is omitted, delete
-the action on the line that is about to be executed.
+Delete an action from the specified line.
-=item A
+=item A *
Delete all installed actions.
-=item W expr
+=item w expr
Add a global watch-expression. We hope you know what one of these
-is, because they're supposed to be obvious. B<WARNING>: It is far
-too easy to destroy your watch expressions by accidentally omitting
-the I<expr>.
+is, because they're supposed to be obvious.
+
+=item W expr
-=item W
+Delete watch-expression
+
+=item W *
Delete all watch-expressions.
-=item O booloption ...
+=item o
+
+Display all options
+
+=item o booloption ...
Set each listed Boolean option to the value C<1>.
-=item O anyoption? ...
+=item o anyoption? ...
Print out the value of one or more options.
-=item O option=value ...
+=item o option=value ...
Set the value of one or more options. If the value has internal
-whitespace, it should be quoted. For example, you could set C<O
+whitespace, it should be quoted. For example, you could set C<o
pager="less -MQeicsNfr"> to call B<less> with those specific options.
You may use either single or double quotes, but if you do, you must
escape any embedded instances of same sort of quote you began with,
as well as any escaping any escapes that immediately precede that
quote but which are not meant to escape the quote itself. In other
words, you follow single-quoting rules irrespective of the quote;
-eg: C<O option='this isn\'t bad'> or C<O option="She said, \"Isn't
+eg: C<o option='this isn\'t bad'> or C<o option="She said, \"Isn't
it?\"">.
For historical reasons, the C<=value> is optional, but defaults to
1 only where it is safe to do so--that is, mostly for Boolean
options. It is always better to assign a specific value using C<=>.
The C<option> can be abbreviated, but for clarity probably should
-not be. Several options can be set together. See L<"Configurable Options">
+not be. Several options can be set together. See L<"Configurable Options">
for a list of these.
-=item < ?
+=item < ?
List out all pre-prompt Perl command actions.
=item < [ command ]
Set an action (Perl command) to happen before every debugger prompt.
-A multi-line command may be entered by backslashing the newlines.
-B<WARNING> If C<command> is missing, all actions are wiped out!
+A multi-line command may be entered by backslashing the newlines.
+
+=item < *
+
+Delete all pre-prompt Perl command actions.
=item << command
Set an action (Perl command) to happen after the prompt when you've
just given a command to return to executing the script. A multi-line
command may be entered by backslashing the newlines (we bet you
-couldn't've guessed this by now). B<WARNING> If C<command> is
-missing, all actions are wiped out!
+couldn't've guessed this by now).
+
+=item > *
+
+Delete all post-prompt Perl command actions.
=item >> command
=item { [ command ]
Set an action (debugger command) to happen before every debugger prompt.
-A multi-line command may be entered in the customary fashion.
-B<WARNING> If C<command> is missing, all actions are wiped out!
+A multi-line command may be entered in the customary fashion.
Because this command is in some senses new, a warning is issued if
you appear to have accidentally entered a block instead. If that's
-what you mean to do, write it as with C<;{ ... }> or even
+what you mean to do, write it as with C<;{ ... }> or even
C<do { ... }>.
+=item { *
+
+Delete all pre-prompt debugger commands.
+
=item {{ command
Add an action (debugger command) to happen before every debugger prompt.
=item ! pattern
Redo last command that started with pattern.
-See C<O recallCommand>, too.
+See C<o recallCommand>, too.
=item !! cmd
Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT) See
-C<O shellBang>, also. Note that the user's current shell (well,
+C<o shellBang>, also. Note that the user's current shell (well,
their C<$ENV{SHELL}> variable) will be used, which can interfere
with proper interpretation of exit status or signal and coredump
information.
-=item @ file
+=item source file
-Read and execute debugger commands from I<file>. I<file> may itself contain
-C<@> commands.
+Read and execute debugger commands from I<file>.
+I<file> may itself contain C<source> commands.
=item H -number
C<exit> twice might work.
Set the C<inhibit_exit> option to 0 if you want to be able to step
-off the end the script. You may also need to set $finished to 0
+off the end the script. You may also need to set $finished to 0
if you want to step through global destruction.
=item R
=item m expr
List which methods may be called on the result of the evaluated
-expression. The expression may evaluated to a reference to a
+expression. The expression may evaluated to a reference to a
blessed object, or to a package name.
+=item M
+
+Displays all loaded modules and their versions
+
+
=item man [manpage]
Despite its name, this calls your system's default documentation
=head2 Configurable Options
-The debugger has numerous options settable using the C<O> command,
+The debugger has numerous options settable using the C<o> command,
either interactively or from the environment or an rc file.
(./.perldb or ~/.perldb under Unix.)
Print only first N elements ('' for all).
+=item C<dumpDepth>
+
+Limit recursion depth to N levels when dumping structures.
+Negative values are interpreted as infinity. Default: infinity.
+
=item C<compactDump>, C<veryCompact>
Change the style of array and hash output. If C<compactDump>, short array
=back
After the rc file is read, the debugger reads the C<$ENV{PERLDB_OPTS}>
-environment variable and parses this as the remainder of a `O ...'
+environment variable and parses this as the remainder of a "O ..."
line as one might enter at the debugger prompt. You may place the
initialization options C<TTY>, C<noTTY>, C<ReadLine>, and C<NonStop>
there.
with two methods: C<IN> and C<OUT>. These should return filehandles to use
for debugging input and output correspondingly. The C<new> method should
inspect an argument containing the value of C<$ENV{PERLDB_NOTTY}> at
-startup, or C<"/tmp/perldbtty$$"> otherwise. This file is not
+startup, or C<"$ENV{HOME}/.perldbtty$$"> otherwise. This file is not
inspected for proper ownership, so security hazards are theoretically
possible.
Other examples include
- $ PERLDB_OPTS="NonStop frame=2" perl -d myprogram
+ $ PERLDB_OPTS="NonStop LineInfo=listing frame=2" perl -d myprogram
which runs script non-interactively, printing info on each entry
into a subroutine and each executed line into the file named F<listing>.
The debugger probably contains enough configuration hooks that you
won't ever have to modify it yourself. You may change the behaviour
-of debugger from within the debugger using its C<O> command, from
+of debugger from within the debugger using its C<o> command, from
the command line via the C<PERLDB_OPTS> environment variable, and
from customization files.
it must be owned by the superuser or the current user, and writable
by no one but its owner.
+You can mock TTY input to debugger by adding arbitrary commands to
+@DB::typeahead. For example, your F<.perldb> file might contain:
+
+ sub afterinit { push @DB::typeahead, "b 4", "b 6"; }
+
+Which would attempt to set breakpoints on lines 4 and 6 immediately
+after debugger initilization. Note that @DB::typeahead is not a supported
+interface and is subject to change in future releases.
+
If you want to modify the debugger, copy F<perl5db.pl> from the
Perl library to another name and hack it to your heart's content.
You'll then want to set your C<PERL5DB> environment variable to say
Perl distribution was uncertain.
Users of B<vi> should also look into B<vim> and B<gvim>, the mousey
-and windy version, for coloring of Perl keywords.
+and windy version, for coloring of Perl keywords.
Note that only perl can truly parse Perl, so all such CASE tools
fall somewhat short of the mark, especially if you don't program
and
L<perlrun>.
+When debugging a script that uses #! and is thus normally found in
+$PATH, the -S option causes perl to search $PATH for it, so you don't
+have to type the path or C<which $scriptname>.
+
+ $ perl -Sd foo.pl
+
=head1 BUGS
You cannot get stack frame information or in any fashion debug functions
projects / p5sagit/p5-mst-13.2.git / blobdiff