#!/usr/bin/env perl
use strict;
use warnings;
use Data::Dumper;

opendir(my $dh, '.') or die $!;
my @files = map { /(.*)\.ctl$/ }readdir $dh;

my %srss;

for (@files) { # $_ is set to each element in @files
        for my $extension(qw(ctl log)) {
                my $file = "$_.$extension";
                open (my $fh, $file) or die $!;
                while (my $line = <$fh>) {
                        while ($line =~ /SRS[_\s]?(\d+)/g) {
                                $srss{$1} = 1;
                        }
                }
        }
}


print join '|', sort {$a <=> $b} keys %srss;
# 111|222|333|2222|3333