Question

Given a method that may fail with warnings and/or errors, I want the error method to show up at the caller. Fir instance this script:

foo(0);         # line 1

sub foo {
    1 / shift;  # line 4
}

Produces the error Illegal division by zero at foo.pl line 4, but I want Illegal division by zero at foo.pl line 1. There should be several ways if I put the method in a module or if I wrap the method body in eval, but I have not found an easy way like this:

sub foo {
    attributeErrorsToCaller; # do some magic
    1 / shift;
}

Is there such a way?

---

EDIT: mirod’s answer comes close not what I was looking for:

Foo::foo(0);         # line 1

package Foo;
use diagnostics -traceonly;
BEGIN { disable diagnostics; }

sub foo {
    enable diagnostics;
    1 / shift;       # line 9
}

Without enable diagnostics the error message is Illegal division by zero at foo.pl line 9.. With enable diagnostics it is still too verbose, but this may also be useful:

Uncaught exception from user code:
    Illegal division by zero at foo.pl line 10.
 at foo.pl line 10
     Foo::foo(0) called at foo.pl line 2

I bet I could hack diagnostics to get exactely the feature I want, but using diagnostics as raw module is probably more recommended.

Answer 1

Would use diagnostics; be enough for you? It will dump the call stack, so the caller is quite easy to find out.

For example in you example:

#!/usr/bin/perl

use strict;
use warnings;
use diagnostics;


foo(0);

sub foo
  { 
    return 1/$_[0];
  }

gives this:

`Illegal division by zero at test_die line 12 (#1)
    (F) You tried to divide a number by 0.  Either something was wrong in
    your logic, or you need to put a conditional in to guard against
    meaningless input.

Uncaught exception from user code:
        Illegal division by zero at test_die line 12.
 at test_die line 12
        main::foo(0) called at test_die line 8