#!/usr/bin/perl

use strict;
use warnings;

my $done = 0;

while (not $done) {
    print "\n\nPlease type the numbers of the messages that are to be released (n-n and n \nare allowable, A for all): ";
    my $input = <STDIN>;
    chomp($input);
    foreach my $range (split(/,/, $input)) {
        $range =~ s/\s*//g;     # Remove whitespace
        if ($range =~ /[Aa]/) {
            # All messages, assume we're done
            print "All messages!\n";
            # ...
            $done = 1;
        }
        elsif ($range =~ /(\d+)        # Single message number
                          (?:          # Can be followed by a dash with a
                            -(\d+)     # second number (which denotes the end
                          )?           # of the range
                         /x) {
            if ($1 and $2) {
                print "Message range: #$1 to #$2\n";
                # ...
            }
            else {
                print "Single message: #$1\n";
                # ...
            }
        }
        elsif ($range =~ /[Qq]/) {
            # Give the user the option to quit.
            $done = 1;
        }
        else {
            # Wrong input
            print "Wrong input!\n";
            # ...
        }
    }
}