#

# relocate.php /path/to/file prefix

# 

# Takes a file as input and a string prefix; reads

# the file as a serialized data blob and strips PREFIX

# from the beginning of each string value within the blob.

# Serializes again and writes output to stdout.

# 

$file = $_SERVER['argv'][1];

$destdir = $_SERVER['argv'][2];

$destdir_len = strlen($destdir);

function relocate_string($value) {

    global $destdir, $destdir_len;

    if (strncmp($value, $destdir, $destdir_len) == 0) {

        $value = substr($value, $destdir_len);

    }

    return $value;

}

function relocate_value($value) {

    if (is_string($value)) {

        $value = relocate_string($value);

    } else if (is_array($value)) {

        $value = relocate_array($value);

    }

    return $value;

}

function relocate_array($array) {

    $result = array();

    foreach ($array as $key => $value) {

        if (is_string($key)) {

            $key = relocate_string($key);

        }

        $result[$key] = relocate_value($value);

    }

    return $result;

}

$input = file_get_contents($file);

# Special case for /etc/pear.conf.

if (strncmp($input, "#PEAR_Config 0.9\n", 17) == 0) {

    echo substr($input, 0, 17);

    $s = substr($input, 17);

} else {

    $s = $input;

}

echo serialize(relocate_value(unserialize($s)));

?>