CODEWITHSUNDEEP
perl
user1424739
user1424739

Reputation: 13685

How to make perl exit with an error code upon use of uninitialized-value?

I don't see how to make perl fail upon use of uninitialized-value. Is there a way to make this the default behavior? Thanks.

https://perlmaven.com/use-of-uninitialized-value

Upvotes: 1

Views: 508

Answers (2)

GMB
GMB

Reputation: 222482

Dave's answer sure is the best pick for the described use case.

Here is another solution, that demonstrates the use of the warning signal handler (see http://perldoc.perl.org/functions/warn.html).

The benefit of using a signal handler is flexibility : you can trap any kind of warning, analyze it and then implement any behavior you like. In the given use case this is an overkill, it but can be useful in more complex cases.

use strict;
use warnings;
use feature "say";

local $SIG{__WARN__} = sub {
    if ($_[0] =~ /^Use of uninitialized value/) {
        die $_[0]; 
    } else { 
        warn $_[0] ;
    }
};

my $foo;
say "Foo is $foo";
say "Dont get here";

Upvotes: 1

Dave Cross
Dave Cross

Reputation: 69264

Something like this perhaps:

#!/usr/bin/perl
use strict;
use warnings;
use warnings FATAL => qw[uninitialized];
use feature 'say';

my $foo;

say "Foo is $foo";
say "Don't get here";

Comment out the FATAL line to see the standard behaviour.

Upvotes: 3

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