#!/usr/bin/perl
#Program name: perlsort3.pl
#  sort numerically using a subroutine.
#  numbers are given in a file (specified on the command [one number per line])

$x = 0;
while (<>)
{
  $someList[$x] = $_;
  $x++;
}
@sortedLines = sort numbers @someList;
print @sortedLines;

sub numbers
{
  if ($a < $b)
    { -1; }
  elsif ($a == $b)
    { 0; }
  else
    { +1; }
}