Is this documented anywhere? Other than in your brain and the code?

perlsyn (yeah, the one nobody reads {grin}) says:

       Plain Old Comments (Not!)

       Much like the C preprocessor, Perl can process line
       directives.  Using this, one can control Perl's idea of
       filenames and line numbers in error or warning messages
       (especially for strings that are processed with eval()).
       The syntax for this mechanism is the same as for most C
       preprocessors: it matches the regular expression
       /^#\s*line\s+(\d+)\s*(?:\s"([^"]*)")?/ with $1 being the
       line number for the next line, and $2 being the optional
       filename (specified within quotes).

       Here are some examples that you should be able to type
       into your command shell:
[download]

and goes on to give some examples.

-- Randal L. Schwartz, Perl hacker

I actually did read perlsyn. I even go back and browse it periodically for fun. I have even written code that had no purpose other than to play with features that I found there. (For instance a program that was designed as a finite state machine, switching states with "goto &foo;".) I sincerely missed this particular point. Actually I remember seeing it, and not seeing why it would be useful, then forgetting it again.

That said, unless I am missing something obvious, I find the above feature to be buggy for perl 5.005_03 on both Windows and Linux. Here is my test:

$ perl
$str = <<FOO;
# line 1 "foo"
sub bar {
    die('gotcha');
}
&bar();
FOO

print "When executed by eval:\n";
eval($str);
print $@;

print "When executed by perl:\n";
open (PERL, "| perl") or die "Cannot start perl: $!";
print PERL $str;
close PERL;
__END__
When executed by eval:
gotcha at (eval 1) line 3.
When executed by perl:
gotcha at foo line 2.
[download]

When I go home tonight I will try this on 5.6 and send a bug report in if I still cannot get it to work.

For the record, I consider myself a Perl hacker, not a perl hacker. (VBG)