#!/usr/bin/perl

# commonStart
# This script determines the string that is the common start of the
# strings passed as command-line arguments
# Cameron Hayne (macdev@hayne.net)  January 2005

use warnings;
use strict;

my @strings = @ARGV;
my $numStrings = scalar(@ARGV);
if ($numStrings < 2)
{
    print "Must supply at least 2 strings as command-line arguents\n";
    exit;
}

my $sep = chr(0); # null character - presumed not to occur in strings
my $common = $strings[0];
for (my $i = 1; $i < $numStrings; $i++)
{
    if ("$common$sep$strings[$i]" =~ /^(.*).*$sep\1.*$/)
    {
        $common = $1;
    }
}

print "$common\n";