$ ./sample.pl my-dev-1
---
classes:
  - all
  - dev

##</code><code>##

#!/usr/bin/perl

use strict;
use warnings;
use YAML qw( Dump );
use Getopt::Std;
use constant { true => 1, false => 0 };
use Data::Dumper;

my $deploy      = 'common';
my $host        = 'unknown';
my $fullhost    = 'none';

my @classes     = ();

my %args   = ();

getopts( 'hr:', \%args );

sub usage {
    my $heredoc = <<EOF;

Usage: sample.pl [-h] hostname

    [ -h ]    print this help message 
EOF
    print $heredoc;
    return $heredoc;
}

# main
if (@ARGV == 0) {
    print "no args\n";
} else {
    $fullhost = $ARGV[$#ARGV];

    $fullhost =~ s/^.*:://;

    if ( $fullhost =~ /(\w+)-(.*)/ ) {
        ( $deploy, $host ) = ( $1, $2 );
    }
}

if ( $args{h} ) { usage() }

if ( $deploy =~ /^my$/ ) {

    # Pushing global classes
    push( @classes, 'all' );

    if ( $host =~ /build-/ ) {
        push( @classes, 'build' );
    }

    # Pushing Dev Classes
    if ( $host =~ /dev-/ ) {
        push( @classes, 'dev' );
    }
} else {
    push( @classes, 'base' );
}

print Dump(
    {
        classes => \@classes,
    }
);

##</code><code>##

#!/usr/bin/perl

use warnings;
use strict;
use Test::More tests => 2;
use Test::Output;

require_ok( "./sample.pl");

is(&usage(), "
Usage: sample.pl [-h] hostname

    [ -h ]    print this help message 
", 'check usage message');

done_testing();

##</code><code>##

$ ./test.pl 
1..2
no args
---
classes:
  - base
ok 1 - require './sample.pl';

Usage: sample.pl [-h] hostname

    [ -h ]    print this help message 
ok 2 - check usage message