#!/usr/bin/env perl
# Copyright 2005 Daniel Cer (daniel.cer@cs.colorado.edu)
#
# This work is licensed under the Creative Commons Attribution-NonCommercial-
# ShareAlike License. To view a copy of this license, visit 
# http://creativecommons.org/licenses/by-nc-sa/2.5/ or send a letter to 
# Creative Commons, 543 Howard Street, 5th Floor, San Francisco, California, 
# 94105, USA.

# bubble_sort - sorts the array referenced by the first argument to this 
# function. 
sub bubble_sort($) { my $ref_entries = shift; my ($i, $j, $swapped);
  for ($i = $#$ref_entries, $swapped=true; $i >= 0 && $swapped; $i--) {
    for ($j = 0,$swapped=false; $j < $i; $j++) {
      if ($$ref_entries[$j+1] < $$ref_entries[$j]) { $swapped=true;
        ($$ref_entries[$j],$$ref_entries[$j+1]) = 
           ($$ref_entries[$j+1],$$ref_entries[$j]); 
      }
    }
  }
}

if ($#ARGV != 0) {
  print stderr "Usage:\n\t$0 (file with numbers to sort)\n";
  exit -1;
}

# read in the entries
$file_name = $ARGV[0];
open fh, $file_name or die "Can't open \"$file_name\"\n";
@entries = <fh>; close fh;

# sort them
bubble_sort(\@entries);

# display the results
foreach $entry (@entries) { print $entry; }