#!/usr/bin/perl
# test_crc.pl - Don Yang (uguu.org)
#
# 03/17/04


use strict;
my (@table, @text);

$ARGV[1] && (srand $ARGV[1]);
die "$0 <outfile>\n" unless( $ARGV[0] );


sub InitTable
{
   my ($i, $j, $crc);

   $#table = 255;
   for($i = 0; ($crc = $i) < 256; $table[$i++] = $crc)
   {
      for($j = 8; $j > 0; $j--)
      {
         $crc = ($crc >> 1) ^ (($crc & 1) ? 0xedb88320 : 0);
      }
   }
}

sub CRC
{
   my ($str) = @_;
   my ($crc);

   for($crc = 0xffffffff; length($str) > 0; $str = substr($str, 1))
   {
      $crc = (($crc >> 8) & 0xffffff) ^ $table[($crc ^ ord($str)) & 255];
   }
   return $crc;
}

sub CreateStrings
{
   my ($o, $i, $j, $s, $c);

   @text = ();
   for($o = 0; $o < 16;)
   {
      $s = '';
      for($j = 0; $j < 1024; $j++)
      {
         $s .= ('a'..'z', 'A'..'Z', '0'..'9')[int(rand 62)];
      }
      $c = CRC($s);
      for($j = 0; $j < 4; $j++)
      {
         $i = chr($c & 0xff);
         if( $i eq "\r" || $i eq "\n" )
         {
            $s = '';
            last;
         }
         $s .= $i;
         $c >>= 8;
      }
      if( length($s) )
      {
         push @text, $s . "\n";
         $o++;
      }
   }
}

sub main
{
   my ($i);
   local (*FILE);

   InitTable();
   CreateStrings();
   open FILE, "> $ARGV[0]" or die $!;
   for($i = 0; $i < 1024; $i++)
   {
      print FILE $text[int(rand 10)];
   }
   close FILE;
}

main();