Jonathan
Peter
Jason
Nick
Stela
Samantha

##</code><code>##

Jonathan
Peter
Jason
Simon
Nick
Stela
Samantha

##</code><code>##

my $file = '/home/yanni/scripts/testfiles/list_names';

open my $NAMES, '+>>', $file || die "What the hell? Can't open file $!\n";

while (<$NAMES>)

 {  
   
    if ($.== 3) {print "\nSimon\n";} 

 }

close ($NAMES);