$SIG{__DIE__} = sub {
    warn "ack: ", join(', ', grep defined, caller(0)), $/;
};

die("I died at line: ", __LINE__);

__output__

ack: main, -, 5, main::__ANON__, 1, 0, 0, 
I died at line: 5 at - line 5.
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_________
broquaint

Or to take this a step further, place the following at the beginning of the script....

use Carp;
$SIG{__DIE__} = \&Carp::confess;
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This turns any die into a confess, giving you a full stack trace. (Of course it does add two to the line numbers reported -- you could fudge this by adding these two statements to a pre-existing line).
Enjoy...

--JAS

$ perl -d trans.pl 
Default die handler restored.

Loading DB routines from perl5db.pl version 1.07
Editor support available.

Enter h or `h h' for help, or `man perldebug' for more help.

main::(trans.pl:1):    open(DICT, "/usr/dict/words");
  DB<1> b 4
  DB<2> c
main::(trans.pl:4):    my $text = join('',<DICT>);
  DB<2>
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From there you can get a stack trace, examine variables, etc.

Happy hunting,
-sam

maybe Devel::TraceSubs would help? something like...

use Devel::TraceSubs 0.02;

my $dbg = Devel::TraceSubs->new();
$dbg->trace( 'my::package::here::' );  ## maybe it's 'main::' in your 
+case?
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it should show a pretty good stack trace. please let me know if it helps, or you have problems using it.

~Particle *accelerates*

If you know the line where the code fails, you can insert   $DB::single=2; on the line before, run under the debugger and hit 'c' to got straight to that line and grab your stacktrace that way. Quick and much less tedious than the single stepping method.

Along the lines of my above (erroneuos) reply, If you know the line where the error occurs, just put a

confess()
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statement at the line immediately before the script fails.

# beginning of program

eval {
    main();
};
if ( $@ ) {
    confess();
}

sub main {
...
}
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#!/usr/bin/perl -w

use strict;
use Carp;

eval {
    main();
};
if ( $@ ) {
    confess();
}

exit;

sub main {
    print "hello world\n";
}
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No cigar.

#!/usr/bin/perl -w

use strict;
use Carp;

eval {
    main();
};
if ( $@ ) {
    confess($@);
}

exit;

sub foo {
    my $aargh = shift;
    
    die $aargh;
}

sub main {
    foo "hello world\n";
}
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I don't get a stack trace. Once it has finished the eval, the stack is no longer there.

I've been in similar circumstances and I use the GUI Debugger and had great success with it. You can expand or contract data structures which is nice and since you can see your code, you can decide where you want to set your breakpoints. Plus it runs great on win32 boxes too.

Hope that helps!

There is no emoticon for what I'm feeling now.

Of course (Doh!) once I know the line where the program is failing, I can set a break in the previous executable line, and if it's the first line in a sub, set a break on the sub.

This has given me enough information for a bug report for the original problem I had, but I could imagine there might be some problems if the code is inside a coderef and/or an eval (yes, I do do tortuous things with coderefs sometimes as fever knows :-).

However, I still think that the debugger could benefit from a better handler to catch $SIG{__DIE__}, enabling you to look at lexical variables in scope at the point where it dies, and the good ol' stack trace. Where or to whom do I post such a suggestion?

Also, I could use (and I am thinking of writing when I get a round tuit) a generic script called confessor.pl, which takes a script and argv list, sets up the die handler which will confess, then requires in the script. I have had a brief stab at this, but there are issues with BEGIN code, and the scripts are not designed to be 'require'd so they do not return true.

Update: Maybe a form of use Carp qw(verbose); should catch $SIG{__DIE__}. Possibly use Carp qw(verbose,catchdie);

Update 2: Just tried the suggestion use diagnostics; or rather perl -Mdiagnostics foobar.pl from anonymonk below. It does the business! Anonymonk++ whoever you are! Sign up to the monastery with an ID, your input is most welcome.

Recently a very interesting post/patch was made to p5p that looks like it could meet your debugging requirements (and make Carp::Assert redundant). If it gets in it will be in version 5.10 however. :-(

--- demerphq
my friends call me, usually because I'm late....

and the scripts are not designed to be 'require'd so they do not return true.

Maybe you could use the do 'stat.pl'; syntax instead?

---

Okay you lot, get your wings on the left, halos on the right. It's one size fits all, and "No!", you can't have a different color.
Pick up your cloud down the end and "Yes" if you get allocated a grey one they are a bit damp under foot, but someone has to get them.
Get used to the wings fast cos its an 8 hour day...unless the Govenor calls for a cyclone or hurricane, in which case 16 hour shifts are mandatory.
Just be grateful that you arrived just as the tornado season finished. Them buggers are real work.

$SIG{__DIE__} = sub {
  my ( $path, $line, $subr );
  my $i = 0;
  while ( $subr = (caller($i++))[3] ) {
    return if $subr eq '(eval)';
  }
  warn "died at: ", join(' line ', (caller)[1,2]), "\n";
  $i = 1;
  while ( ($path, $line) = (caller($i++))[1,2] ) {
    warn "caller:  $path line $line\n";
  }
};
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