#!/usr/bin/perl
use strict;
use warnings;

open(FH, "<","./file1.txt") or die "Can't Open File1\n";
open(BH, "<","./file2.txt") or die "Can't Open File2\n";

my $pattern='^LOC_Os0[1-7]g[0-9]*.[0-9]\s';

while(my $line1 = <FH>)
{
        chomp($line1);
        #print "Line1:$line1\n";
        if( $line1=~ /$pattern/)
        {
                while(my $line2 = <BH>)
                {
                        chomp($line2);

                        if($line2 =~ /$pattern/)
                        {
                                if($line1 eq $line2)
                                {
                                        print "Matches: ". $line1;
                                }
                                else
                                {
                                        print "nothing to print\n";
                                }
                        }
                }
                seek(BH,0,0);
        }
}
close(FH);
close(BH);