#! perl -slw
use strict;
use Carp;
use Try::Tiny;

use constant {
    ERROR123 => 'Divisor is undefined',
    ERROR456 => 'Divisor is zero',
};

sub divide {
    my( $e, $d ) = @_;
    croak ERROR123 unless defined $d;
    croak ERROR456 if $d == 0;
    return $e / $d;
}

my $result;
try{
    $result = divide( @ARGV );
} catch {
    die "You forgot to supply the second argument\n" if $_ =~ ERROR123;
    die "Dividing anything by zero is infinity\n"    if $_ =~ ERROR456;
    die "Unknown error $_\n";
};

print "Result: $result";