# Create some files
$touch {1..3}{a..c}.{ctl,log}
$ls
1a.ctl  1a.log  1b.ctl  1b.log  1c.ctl  1c.log  2a.ctl  2a.log  2b.ctl  2b.log  2c.ctl  2c.log  3a.ctl  3a.log  3b.ctl  3b.log  3c.ctl  3c.log  junk.pl
$echo "SRS_222" >> 1c.ctl
$echo "SRS_333" >> 1c.log
$echo 'SRS_111SRS_2222SRS_3333' > 1a.log

##</code><code>##

#!/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

##</code><code>##

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

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

my %hashSlice;
@hashSlice{@files} = undef;

my $srss;
$srss->{files} = { %hashSlice } ;

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) {
                                $srss->{files}{$_}{$extension}{$1} = 'Found';
                        }
                }
        }
}

dd $srss;

{
  files => {
    "1a" => { log => { 111 => 1, 2222 => 1, 3333 => 1 } },
    "1b" => undef,
    "1c" => { ctl => { 222 => 1 }, log => { 333 => 1 } },
    "2a" => undef,
    "2b" => undef,
    "2c" => undef,
    "3a" => undef,
    "3b" => undef,
    "3c" => undef,
  },
}