perl deferring die to calling method

[arcnon]

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';
}

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?

[robin]

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";
}

[Old_Gray_Bear]

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'.

[ioannis]

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 ]}" ; 
}

[bart]

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.

[rfojta]

I would rather use B::foo(); Try that.

[fmerges]

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,

[chas]

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.)