use strict;
use warnings;
use Fcntl ':flock';

my @search;
my $query = "perl";

open(FILE, "/Users/adrianh/Desktop/myfile.txt") or die;
flock(FILE, LOCK_SH) or die;
foreach my $line (<FILE>) {
	chomp($line);
	push @search, $line if $line =~ m/\Q$query/;
}
close(FILE) or die;