Slightly off topic but nonetheless interesting: If you want the last 100 bytes of a file, this is VERY fast (and scales beautifully for very large files):

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

if (open (FH, $ARGV[0]))
{
  seek FH, -100, 2;
  while (<FH>)
  {
    print $_;
  }
  close (FH);
}
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