#! /usr/bin/perl
use v5.12;
use warnings;

## 2/7/19

    open CONFIG, '<', 'three_Freds';
    open OUTPUT, '>', 'three_Freds.out':

    my $three_Freds = $ARGV[0];
    if (! defined $three_Freds) {
       die "Usage: $0 filename";
       }
  
    while (<$CONFIG>) {     #take one line of input at a time
    chomp;
      s/fred/\n/gi;         
      s/Wilma/Fred/gi;
      s/\n/Wilma/g;
      print $OUTPUT $_ ;
    }