Put the "try" code inside an eval block, then check the value of $@. Example:

#! /usr/bin/perl -w
use strict;

for my $i ( 2, 1, 0 ) {
    for my $j ( 2, 1 ) {
        eval { 
            print "$j / $i = " . $j / $i . $/;
        };
        if ( $@ ) {
            warn "Warning: $@";
        }
    }
}

__END__
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