File:USA counties FIPS text addressable.svg

Although I don't foresee any further need for processing, I should point out that the size of the file is such that even simple changes require a program to be run. Perl is freely downloaded and can run as a standalone (ActivePerl) or under Cygwin. The script I ran was not exactly rocket science, but I'll post it hopefully to embolden anyone who sees a need for further modification of the file. The following is the entire program, which processed the file in about two seconds:

use integer;
use strict;
use warnings;

# Open files

open (OLD, "< input.txt" ) || die ("no input?");
open (NEW, "> output.txt" ) || die ("Couldn't open output file: $!");
my (@a, $code, $class, $tmp);

while (<OLD>)
{
push @a,$_;
if (/(\d\d\d\d\d)/) {$code=$1};
if (/class/) {$class=@a};
if (/path/)
   {
   if ($class) {$a[$class-1]=('     class="land s' . $code . '"'."\n")} else {print "no class: $code"};
   while ($tmp=shift(@a)) {print NEW $tmp};
   }
};