This worked perfectly!! I am studying the code right now. I understand the majority of it. I have one question though...

Code for reference:

      1 #!/usr/local/bin/perl
      2
      3 use strict;
      4
      5 my $max = 0;
      6
      7 sub readfile {
      8   my $fn=shift;
      9   my @ar;
     10
     11   open IN,"<$fn" || die "Couldn't open '$fn': $!";
     12   ## snarf the header
     13   scalar <IN>;
     14   ## read the rest
     15   while (<IN>) {
     16     chomp;
     17     push @ar,$_;
     18     $max = $_ if $_ > $max;
     19   }
     20   close IN;
     21
     22   @ar;
     23 }
     24
     25
     26 ## load the files into arrays
     27 my @a=readfile 'f1.lst';
     28 my @b=readfile 'f2.lst';
     29 my @c=readfile 'f3.lst';
     30
     31 ## iterate until all arrays are empty
     32 for (my $i = 0; $i <= $max; $i++)
     33 {
     34   next unless $a[0] == $i || $b[0] == $i || $c[0] == $i;
     35
     36   ## print them out (if they match)
     37   printf "%5s", $a[0]==$i ? scalar shift @a : undef;
     38   print " | ";
     39   printf "%5s", $b[0]==$i ? scalar shift @b : undef;
     40   print " | ";
     41   printf "%5s", $c[0]==$i ? scalar shift @c : undef;
     42
     43   print "\n";
     44 }
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My only question is: In lines 36-41 you have a snippet  scalar shift @array. What is this doing? :) Thank you very much!!

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- Jim