Well done for consulting the docs - they really are rather good.

You might also want to know that a simple assignment can be chomped as well so you could write this as chomp ($output = $_); instead. Full demo script:

#!/usr/bin/env perl
use strict;
use warnings;

$_ = "foo\n";
print "in: '$_'\n";
chomp (my $output = $_);
print "out: '$output'\n";
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I concur with others in warning against shelling out to find for your original task, not least because of the vagaries of the arguments and output formats of such a utility across platforms. Stick with the modules which come with Perl or are on CPAN for better portability.