cookie.php文件如下:

# Netscape HTTP Cookie File
# http://curl.haxx.se/rfc/cookie_spec.html
# This file was generated by libcurl! Edit at your own risk.
 
.google.com    TRUE    /   FALSE   1305843382  cookiename  the value
.yahoo.com TRUE    /   FALSE   1305843382  another_cookie  it's value

<?php
    /**
     * 获取淘宝单个Cookie值
     *
     */
    function getCookieVal($name, $domain) {//alimama.com
        $file_name = dirname(__FILE__) . '/cookie.php';
        $content = file_get_contents($file_name);
        $cookies = extractCookies($content);
        foreach ($cookies as $val) {
            if ($val['domain'] == $domain and $val['name'] == $name) {
                return $val['value'];
            }
        }
        return '';
    }


    /**
     * Extract any cookies found from the cookie file. This function expects to get
     * a string containing the contents of the cookie file which it will then
     * attempt to extract and return any cookies found within.
     *
     * @param string $string The contents of the cookie file.
     *
     * @return array The array of cookies as extracted from the string.
     *
     */
    function extractCookies($string) {

        $lines = explode(PHP_EOL, $string);

        foreach ($lines as $line) {

            $cookie = array();

            // detect httponly cookies and remove #HttpOnly prefix
            if (substr($line, 0, 10) == '#HttpOnly_') {
                $line = substr($line, 10);
                $cookie['httponly'] = true;
            } else {
                $cookie['httponly'] = false;
            }

            // we only care for valid cookie def lines
            if (strlen($line) > 0 && $line[0] != '#' && substr_count($line, "\t") == 6) {

                // get tokens in an array
                $tokens = explode("\t", $line);

                // trim the tokens
                $tokens = array_map('trim', $tokens);

                // Extract the data
                $cookie['domain'] = $tokens[0]; // The domain that created AND can read the variable.
                $cookie['flag'] = $tokens[1];   // A TRUE/FALSE value indicating if all machines within a given domain can access the variable.
                $cookie['path'] = $tokens[2];   // The path within the domain that the variable is valid for.
                $cookie['secure'] = $tokens[3]; // A TRUE/FALSE value indicating if a secure connection with the domain is needed to access the variable.

                $cookie['expiration-epoch'] = $tokens[4];  // The UNIX time that the variable will expire on.   
                $cookie['name'] = urldecode($tokens[5]);   // The name of the variable.
                $cookie['value'] = urldecode($tokens[6]);  // The value of the variable.
                // Convert date to a readable format
                $cookie['expiration'] = date('Y-m-d h:i:s', $tokens[4]);

                // Record the cookie.
                $cookies[] = $cookie;
            }
        }

        return $cookies;
    }
?>

参考资料：
http://stackoverflow.com/questions/410109/php-reading-a-cookie-file