hey choroba, I've tried adding curly brackets but i still cannot figure out what the issue is, please help? Thank you

Have you read perlintro?

for ( ... ) { # start something

    for ( ... ) { ... }

} # end something

Hello Anonmous monk, I'm making progress:

foreach (<$ah>)

{
 my @text = split(/\t/);
 for my $value (@text[11, 14, 17])
 
    { 
 


    
    if ($bHash{ $text[3] } eq $value) {
        $bHash{ $text[0] } = $value;
        last;
                                      }
    print OUT2 join( "\t", @text[1,2,3,4,11,5,6,8,7,11,12]),"\t1\t1\n"
+;
    }
    }

close $ah;
[download]

it works however the results seem to be duplicated? Thank you

That's strange, even if I use just the original column i.e. 11 the results are generated but not correctly:

foreach (<$ah>)

{
 my @text = split(/\t/);
 for my $value (@text[11])
 
    { 
 
    
    if ($bHash{ $text[3] } eq $value) 
    
                {
                $bHash{ $text[0] } = $value;
                last;
                }
                
    print OUT2 join( "\t", @text[1,2,3,4,11,5,6,8,7,11,12]),"\t1\t1\n"
+;
    }
    }

close $ah;
[download]