Differences between version 25 and predecessor to the previous major change of PerlOneLiners.
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| Newer page: | version 25 | Last edited on Thursday, May 19, 2005 5:56:59 pm | by AristotlePagaltzis | Revert |
| Older page: | version 24 | Last edited on Wednesday, May 11, 2005 2:57:40 pm | by CraigBox | Revert |
@@ -43,15 +43,25 @@
</verbatim>
Note that you can use any punctuation as the separator in an <tt>s///</tt> command, and if you have backslashes or even need literal slashes in your pattern then doing this can increase clarity.
-!! sh -x
a Perl script
+!! Trace execution in
a [
Perl]
script
-If you're just trying to get
a printout of
each line of Perl
code as it executes
(the way that
sh -x provides
for shell
scripts), you can't use Perl
's -D switch. Instead do this
:
+Getting
a trace showing
each executed
line of code in sequence
(think <tt>
sh -x</tt> but
for [Perl]
scripts) is not obvious. perl(1)
's <tt>
-D</tt>
switch itself does not provide such functionality, but you can get there like so
:
<verbatim>
$ PERLDB_OPTS="NonStop=1 AutoTrace=1 frame=2" perl -dS program
</verbatim>
+
+Another option is to install the [Devel::Trace | http://search.cpan.org/dist/Devel-Trace/] module and simply use it on the script using the <tt>-d:Trace</tt> argument:
+
+<verbatim>
+$ perl -d:Trace program
+</verbatim>
+
+This does not work everywhere, but is has the advantage that you can easily influence the amount of trace output from within the script. [Perl] developers will therefore probably prefer to use the module.
+
+''This really belongs on a ~PerlNotes page, not here.''
!! List all currently running processes
This is useful if you suspect that ps(1) is not reliable, whether due to a RootKit or some other cause. It prints the process ID and command line of every running process on the system (except some "special" kernel processes that lie about/don't have command lines).
