Hi, try this

open(FH1,"+>Result_file.txt") or die "Cannot create file $!\n";
open(FH,"<Input_file.dat") or die "Cannot read $!\n";
while(<FH>) {    
    my $data=$_;
    chomp($data);
    print FH1 "DATA:$data\n" if(grep/$data/,@tag);
}
close(FH);
[download]

Punitha.