#!/usr/bin/perl
use strict;

while (<DATA>) {
    my @nodes = split ('/');
    print $nodes[-1];
}

__DATA__
/home/users/me/proteins/1hc9.txt
/home/users/me/proteins/193l.txt
/home/users/me/proteins/1trz.txt
/home/users/me/proteins/2psg.txt