#!/usr/bin/perl -Tw

use strict;
use warnings;

my $file = "/usr/local/app/etc/app.conf";
my @match = eval {
    use Fcntl qw/:DEFAULT/;
    local *FH;
    sysopen FH, $file, O_RDONLY;
    flock FH, 8;
    map { chomp; qr/$_/ } <FH>;
} if (-e $file && -r _);