#!/usr/bin/perl
use warnings;
use strict;
use Tie::File;
use File::Copy;
use Sys::Hostname;

my $host = hostname;
my $group = 'sbo';
my $newstring = 'sbo::18659:x0929,x1465,x1368,x5552';
my $backup = "/tmp/groups";
copy ("$backup", "$backup.tmp") or die "can not copy $backup";
tie my @lines, 'Tie::File', "$backup" or die "can not open $backup $!";
for (@lines) {
    if (/$group/) {
        $_ .= $newstring;
        last;
    }
}
untie @lines;
print "\n $host \n";