perl deferring die to calling method

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

sorry I don't really know how to exactly phase my question. Hopefully the example can show what I can't phase right.

A.pm
-----------
package A
use B;

B->foo();

B.pm
-----------
package B
sub foo{
     die 'your data is screwed';
}
[download]

When it dies it yeilds 'your data is screwed at B.pm line x'

what I would like is the die to report 'your data is screwed at A.pm line x'. x being the line number where B->foo was called.

What is the best way to accomplish this?

Comment on perl deferring die to calling method Download Code

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Re: perl deferring die to calling method by robin (Chaplain) on Dec 09, 2005 at 23:03 UTC
Instead of using `die`, use `croak` from the Carp package. It’s designed for exactly this situation. `## This is B.pm ## package B; use Carp 'croak'; sub foo { croak "Your data is screwed"; }` [download]	[reply] [d/l] [select]
Re: perl deferring die to calling method by Old_Gray_Bear (Bishop) on Dec 09, 2005 at 23:05 UTC
Look at Carp.pm: carp() -- warns of an error; reports the error as having occured in the calling routine, not the routine that contains the 'carp'. ---- I Go Back to Sleep, Now. OGB	[reply]
Re: perl deferring die to calling method by ioannis (Abbot) on Dec 10, 2005 at 01:56 UTC
You could also use caller(). In the example bellow, I have renamed the package name from B.pm to Bb.pm -- so we don't load from the official B namespace. `package Bb; sub foo { die "your data is screwed at @{[ caller ]}" ; }` [download]	[reply] [d/l]
Re: perl deferring die to calling method by bart (Canon) on Dec 10, 2005 at 22:38 UTC
As an aside, just this warning: Do not ever use "B" as a name for a test module. The reason is because B actually exists — even more: it comes with perl.	[reply]
Re: perl deferring die to calling method by rfojta (Initiate) on Dec 10, 2005 at 11:42 UTC
I would rather use B::foo(); Try that.	[reply]
Re^2: perl deferring die to calling method by fmerges (Chaplain) on Dec 10, 2005 at 14:00 UTC
Hi, I would also do so... If you were using OO then calling B->foo() would be the best method, but on your example you're not using OO only funcion call, and when calling it with B->foo(), you must know that the first argument in @_ is the package name 'B'. So go for B::foo() or take a look at the Exporter module. Also is good to read the manuals about perlref, perlboot. There was also a module, think it was by Brian D Foy, something to make alias to the package names inside your package scope... Regards, fmerges at irc.freenode.net	[reply]
Re: perl deferring die to calling method by chas (Priest) on Dec 10, 2005 at 20:47 UTC
Just a comment: as others have implicitly noted, your package declarations should end with a semicolon. (Otherwise, I don't believe your code will compile.)	[reply]


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