mapping warning from an eval code to actual line in text

ISAI student has asked for the wisdom of the Perl Monks concerning the following question:

Hello all. I am running a very lengthy code (too lengthy to upload, and may be proprietary). I am getting these warnings:

        eval {...} called at /edata/eng/ldagan/voodoo_from_1.1.7.b4/bi
+n/../DesignLibs/ScriptLib/Generic/WMPerl/voodoo/voodooThreads.pm line
+ 73 thread 3
Use of uninitialized value $_ in pattern match (m//) at (eval 60) line
+ 1, <$SIM_F> line 50.
Use of uninitialized value $_ in pattern match (m//) at (eval 61) line
+ 1, <$SIM_F> line 50.
[download]

I have tried to look, but could not find any pattern match that uses $_ in the file. I could be missing something, of course. Line 73 is:

$thread = threads->create(\&executeSimThread, $tb, $i, "Thread data " 
+. $i, $all_shary_for_subs, $global_non_share_ref  );
[download]

I could not find in the subroutine any usage of $_ in pattern matching. Thanks.

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Re: mapping warning from an eval code to actual line in text by choroba (Cardinal) on May 10, 2013 at 11:27 UTC
Note that the special variable $_ does not have to be specified in pattern matching: `#!/usr/bin/perl use warnings; undef $_; $x = 'abcd'; print 'yes' if $x = /a/;` [download] The above code gives no output and the following warning: `Use of uninitialized value $_ in pattern match (m//) at ./1.pl line 6.` [download] لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ	[reply] [d/l] [select]
Re^2: mapping warning from an eval code to actual line in text by ISAI student (Scribe) on May 10, 2013 at 11:37 UTC
Good one... I'll have a look. Still don't know how to map the numbers in eval to the code... But, it gives me something to try... Thanks.	[reply]
Re: mapping warning from an eval code to actual line in text by BrowserUk (Patriarch) on May 10, 2013 at 11:56 UTC
See Re: Re: Re: Line Numbers for an idea that might allow you to track down your evals more easily. With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply]
Re: mapping warning from an eval code to actual line in text by kcott (Archbishop) on May 10, 2013 at 11:39 UTC
G'day ISAI student, "I could not find in the subroutine any usage of $_ in pattern matching. Thanks." `$_` is the default variable to match against (see perlrequick). So, `$_ =~ /$pat/` can be written as just `/$pat/`. I can only suggest that you might need to be looking for constructs like: `if (/$pat/) { ... for (m{$pat}g) { ...` [download] -- Ken	[reply] [d/l] [select]
Re: mapping warning from an eval code to actual line in text by tobyink (Canon) on May 10, 2013 at 12:12 UTC
`eval q{#line 1 "blah blah" die "Hello" if 1; } or die @$;` [download] See "Plain Old Comments (Not!)" in perlsyn `package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name`	[reply] [d/l]