Re^11: incrementing already existing file

[broomduster]

In this section of your code:

while ( <MYFILE> ) {
    chomp;
    my( $label, $index, $value ) = ( split /\s+/ )[3, 5, -1];
    
    $a_vals[ $index ] = $value;
    $b_vals[ $index ] = $value;
}

You need to check the value of $index to get the values for type 'A' into @a_vals, similarly for the 'B' values. The way you have it, you only get 'B' values because they are the last ones in MYFILE, and you are putting the same things into both @a_vals and @b_vals. Since the 'B' values come in last, they overwrite the corresponding 'A' values in @a_vals. You can use the same kind of if/elsif/else logic as in your other loop to fix this(but see comments below on ways to improve that).

Now for this part of the loop over NEWF:

if ($label eq "A"){
$fields[-2] = $a_vals[ $index ]
    
   }
   if ($label eq "B"){
$fields[-2] = $b_vals[ $index ]

You should use if / elsif / else here:

if ($label eq "A") {
    $fields[-2] = $a_vals[ $index ]
}
elsif ($label eq "B") {
    $fields[-2] = $b_vals[ $index ]
}
else {
    print "OOPS!  bad label\n";  # complain if something is fishy
}

You're getting there.