my @patterns;
foreach my $pattern (`ls`) {
    chomp $pattern;
    push @patterns, qr/\Q$pattern\E/;
}

open(IN,"test.txt") or die "Can't open test.txt: $!\n";
while(my $line = <IN>) {
    chomp $line;
    foreach my $pattern (@patterns) {
        print "Match found\n" if $line =~ $pattern;
    }
}