quick replace with check.

gistfile1.txt

<?php

if(!isset($argv[1]) || !isset($argv[2])) {
  echo "Not enough arguments\n";
	exit(-1);
}

$infile = $argv[1];
$outfile = $argv[2];

$content = str_replace("couchbase.so", "couchbase.dll", file_get_contents($infile));
file_put_contents($outfile, $content);

?>