#!/usr/bin/perl

use strict;
use warnings;

my $url = "http://172.20.37.115:8080/se/1.0/provision/subscribers/198968";

# use rindex to get the position of the rightmost / character, add 1 
# use substr to extract the remainder of the string after this position
# perldoc -f rindex
# perldoc -f substr

my $subscriber = substr( $url, ( rindex($url, '/') + 1 ) );

print "$subscriber";