Catching warnings

catch_warnings.pl

#!perl

use strict;
use warnings;
use 5.010;

my $escape = 0;

while (not $escape) {

    # Signal handler style

    local $SIG{__WARN__} = sub { say 'caught you'; $escape = 1 };
    my $substring = rand > 0.9 ? undef : "moo";
    say "Now substring is $substring";

}

while (1) {

    # exception style

    use warnings FATAL => qw/uninitialized/;
    my $substring = rand > 0.9 ? undef : "moo";

    eval {

        say "Now substring is $substring";

    };

    if (my $fatalled_warning = $@) {

        say "caught you: $fatalled_warning";
        last;

    }

}