#!/usr/bin/perl -w 
use strict;   #always use strict

my %sortKey;

open (INFILE, "filename");   #open the file
while <INFILE> { #iterate through the file line by line
   my @tmp = split /,/;   #split the file on the comma
   
   #for the sake of the example we will say that the first 
   #element of the file is what you want to sort on
   #so we will make it the key to our hash
   $sortKey{$tmp[0]}=$_;
}

open (OUTFILE ">outfile");

#this will take the keys, shove them in an array, sort 
#them and set $key equal to the current sorted key
foreach my $key (sort(keys(%sortKey))) {
   print OUTFILE " %sortKey{$key};
}