Translate debug code to a debugging technique

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

I found myself using cluck() today. Nothing wrong about that, except I couldn't find a nice way to ditch it for perl -d. I'm trying to see how to schedule/stop for a stack trace in this situation, with the debugger:


sub message_id($)
{
    my $tr = shift; defined $tr or cluck(), return undef;
    $tr->isa('HTML::Element')   or return undef;
    my $td = ($tr->content_list())[0];
    return $td->as_trimmed_text();
}
[download]

This function is called hundreds of times, I only want a backtrace when it's about to return in that specific condition.
(and yeah, I know cluck works perfectly there).

Thanks in advance

Comment on Translate debug code to a debugging technique Download Code

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Re: Translate debug code to a debugging technique by shenme (Priest) on Oct 02, 2004 at 04:03 UTC
Would "$DB::single = 1;" be enough to return you control while in the debugger? You could then do whatever you needed to track down your problem?	[reply]
Re^2: Translate debug code to a debugging technique by hlen (Beadle) on Oct 02, 2004 at 04:29 UTC
Seems nice =). I'm trying to test that, but am having some trouble. My code forks, and the debugger is opening some `Daughter' windows, and then I can't get it to respond. It seems to be entering an infinite loop when I close them. I need some practice, maybe there's a way to make it not follow children. I still wonder if there's a way to do that without editing the code, out of curiosity. Thanks a lot.	[reply]
Re: Translate debug code to a debugging technique by Prior Nacre V (Hermit) on Oct 02, 2004 at 05:38 UTC
You could call `cluck()` conditionally based on the value of `$^D`. Something as simple as `( $^D \|\| cluck() )` may suffice. See both perlrun and perldebug for a number of gotchas with this method. Regards, PN5	[reply] [d/l] [select]