open my $fh1, '<', 'file1.txt' or die "can't open the damned 'file1.txt' file!: $!";
open my $fh2, '<', 'file2.txt' or die "can't open the bloody 'file2.txt' file!: $!";

##</code><code>##

my @file = <$fh>;

foreach $row (@file){
    ...

##</code><code>##

while (my $row = <$fh>){
    chomp $row; # remove line ending
    ...