Hi,

Let see this code,

use strict;
use warnings;

my $firstString='Trap';
my $secondString='hair';

open my $text, "<test.txt" or die "Dead";
while(<$text>){
        print if (m/($firstString|$secondString)/i)
}
[download]

file:

Transformers robots in disguise
I whip my hair back and forth
I will catch a dog with a trap

It prints the output as,

I whip my hair back and forth
I will catch a dog with a trap

But as you want to match the 'Trap' first which is in the third line, should be printed first and 'Hair' should be printed next. Is that you wanted?