/lib/PEAR/HTTP/HTTP.php

<?php



/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */



/**

 * HTTP

 *

 * PHP versions 4 and 5

 *

 * @category  HTTP

 * @package   HTTP

 * @author    Stig Bakken <ssb@fast.no>

 * @author    Sterling Hughes <sterling@php.net>

 * @author    Tomas V.V.Cox <cox@idecnet.com>

 * @author    Richard Heyes <richard@php.net>

 * @author    Philippe Jausions <jausions@php.net>

 * @author    Michael Wallner <mike@php.net>

 * @copyright 2002-2008 The Authors

 * @license   http://www.opensource.org/licenses/bsd-license.php  New BSD License

 * @version   CVS: $Id: HTTP.php,v 1.56 2008/08/31 20:15:43 jausions Exp $

 * @link      http://pear.php.net/package/HTTP

 */



/**

 * Miscellaneous HTTP Utilities

 *

 * PEAR::HTTP provides static shorthand methods for generating HTTP dates,

 * issueing HTTP HEAD requests, building absolute URIs, firing redirects and

 * negotiating user preferred language.

 *

 * @category HTTP

 * @package  HTTP

 * @author   Stig Bakken <ssb@fast.no>

 * @author   Sterling Hughes <sterling@php.net>

 * @author   Tomas V.V.Cox <cox@idecnet.com>

 * @author   Richard Heyes <richard@php.net>

 * @author   Philippe Jausions <jausions@php.net>

 * @author   Michael Wallner <mike@php.net>

 * @license  http://www.opensource.org/licenses/bsd-license.php  New BSD License

 * @abstract

 * @version  Release: $Revision: 1.56 $

 * @link     http://pear.php.net/package/HTTP

 */

class HTTP

{

    /**

     * Formats a RFC compliant GMT date HTTP header.  This function honors the

     * "y2k_compliance" php.ini directive and formats the GMT date corresponding

     * to either RFC850 or RFC822.

     *

     * @param mixed $time unix timestamp or date (default = current time)

     *

     * @return mixed  GMT date string, or false for an invalid $time parameter

     * @access public

     * @static

     */

    function Date($time = null)

    {

        if (!isset($time)) {

            $time = time();

        } elseif (!is_numeric($time) && (-1 === $time = strtotime($time))) {

            return false;

        }



        // RFC822 or RFC850

        $format = ini_get('y2k_compliance') ? 'D, d M Y' : 'l, d-M-y';



        return gmdate($format .' H:i:s \G\M\T', $time);

    }



    /**

     * Negotiates language with the user's browser through the Accept-Language

     * HTTP header or the user's host address.  Language codes are generally in

     * the form "ll" for a language spoken in only one country, or "ll-CC" for a

     * language spoken in a particular country.  For example, U.S. English is

     * "en-US", while British English is "en-UK".  Portugese as spoken in

     * Portugal is "pt-PT", while Brazilian Portugese is "pt-BR".

     *

     * Quality factors in the Accept-Language: header are supported, e.g.:

     *      Accept-Language: en-UK;q=0.7, en-US;q=0.6, no, dk;q=0.8

     *

     * <code>

     *  require_once 'HTTP.php';

     *  $langs = array(

     *      'en'    => 'locales/en',

     *      'en-US' => 'locales/en',

     *      'en-UK' => 'locales/en',

     *      'de'    => 'locales/de',

     *      'de-DE' => 'locales/de',

     *      'de-AT' => 'locales/de',

     *  );

     *  $neg = HTTP::negotiateLanguage($langs);

     *  $dir = $langs[$neg];

     * </code>

     *

     * @param array  $supported An associative array of supported languages,

     *                          whose values must evaluate to true.

     * @param string $default   The default language to use if none is found.

     *

     * @return string  The negotiated language result or the supplied default.

     * @static

     * @access public

     */

    function negotiateLanguage($supported, $default = 'en-US')

    {

        $supp = array();

        foreach ($supported as $lang => $isSupported) {

            if ($isSupported) {

                $supp[strtolower($lang)] = $lang;

            }

        }



        if (!count($supp)) {

            return $default;

        }



        if (isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {

            $match = HTTP::_matchAccept($_SERVER['HTTP_ACCEPT_LANGUAGE'],

                                        $supp);

            if (!is_null($match)) {

                return $match;

            }

        }



        if (isset($_SERVER['REMOTE_HOST'])) {

            $lang = strtolower(end($h = explode('.', $_SERVER['REMOTE_HOST'])));

            if (isset($supp[$lang])) {

                return $supp[$lang];

            }

        }



        return $default;

    }



    /**

     * Negotiates charset with the user's browser through the Accept-Charset

     * HTTP header.

     *

     * Quality factors in the Accept-Charset: header are supported, e.g.:

     *      Accept-Language: en-UK;q=0.7, en-US;q=0.6, no, dk;q=0.8

     *

     * <code>

     *  require_once 'HTTP.php';

     *  $charsets = array(

     *      'UTF-8',

     *      'ISO-8859-1',

     *  );

     *  $charset = HTTP::negotiateCharset($charsets);

     * </code>

     *

     * @param array  $supported An array of supported charsets

     * @param string $default   The default charset to use if none is found.

     *

     * @return string  The negotiated language result or the supplied default.

     * @static

     * @author Philippe Jausions <jausions@php.net>

     * @access public

     * @since  1.4.1

     */

    function negotiateCharset($supported, $default = 'ISO-8859-1')

    {

        $supp = array();

        foreach ($supported as $charset) {

            $supp[strtolower($charset)] = $charset;

        }



        if (!count($supp)) {

            return $default;

        }



        if (isset($_SERVER['HTTP_ACCEPT_CHARSET'])) {

            $match = HTTP::_matchAccept($_SERVER['HTTP_ACCEPT_CHARSET'],

                                        $supp);

            if (!is_null($match)) {

                return $match;

            }

        }



        return $default;

    }



    /**

     * Negotiates content type with the user's browser through the Accept

     * HTTP header.

     *

     * Quality factors in the Accept: header are supported, e.g.:

     *      Accept: application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8

     *

     * <code>

     *  require_once 'HTTP.php';

     *  $contentType = array(

     *      'application/xhtml+xml',

     *      'application/xml',

     *      'text/html',

     *      'text/plain',

     *  );

     *  $mime = HTTP::negotiateContentType($contentType);

     * </code>

     *

     * @param array  $supported An associative array of supported MIME types.

     * @param string $default   The default type to use if none match.

     *

     * @return string  The negotiated MIME type result or the supplied default.

     * @static

     * @author Philippe Jausions <jausions@php.net>

     * @access public

     * @since  1.4.1

     */

    function negotiateMimeType($supported, $default)

    {

        $supp = array();

        foreach ($supported as $type) {

            $supp[strtolower($type)] = $type;

        }



        if (!count($supp)) {

            return $default;

        }



        if (isset($_SERVER['HTTP_ACCEPT'])) {

            $accepts = HTTP::_sortAccept($_SERVER['HTTP_ACCEPT']);



            foreach ($accepts as $type => $q) {

                if (substr($type, -2) != '/*') {

                    if (isset($supp[$type])) {

                        return $supp[$type];

                    }

                    continue;

                }

                if ($type == '*/*') {

                    return array_shift($supp);

                }

                list($general, $specific) = explode('/', $type);

                $general .= '/';

                $len = strlen($general);

                foreach ($supp as $mime => $t) {

                    if (strncasecmp($general, $mime, $len) == 0) {

                        return $t;

                    }

                }

            }

        }



        return $default;

    }



    /**

     * Parses a weighed "Accept" HTTP header and matches it against a list

     * of supported options

     *

     * @param string  $header    The HTTP "Accept" header to parse

     * @param array   $supported A list of supported values

     *

     * @return string|NULL  a matched option, or NULL if no match

     * @access private

     * @static

     */

    function _matchAccept($header, $supported)

    {

        $matches = HTTP::_sortAccept($header);

        foreach ($matches as $key => $q) {

            if (isset($supported[$key])) {

                return $supported[$key];

            }

        }

        // If any (i.e. "*") is acceptable, return the first supported format 

        if (isset($matches['*'])) {

            return array_shift($supported);

        }

        return null;

    }



    /**

     * Parses and sorts a weighed "Accept" HTTP header

     *

     * @param string  $header The HTTP "Accept" header to parse

     *

     * @return array  a sorted list of "accept" options

     * @access private

     * @static

     */

    function _sortAccept($header)

    {

        $matches = array();

        foreach (explode(',', $header) as $option) {

            $option = array_map('trim', explode(';', $option));



            $l = strtolower($option[0]);

            if (isset($option[1])) {

                $q = (float) str_replace('q=', '', $option[1]);

            } else {

                $q = null;

                // Assign default low weight for generic values

                if ($l == '*/*') {

                    $q = 0.01;

                } elseif (substr($l, -1) == '*') {

                    $q = 0.02;

                }

            }

            // Unweighted values, get high weight by their position in the

            // list 

            $matches[$l] = isset($q) ? $q : 1000 - count($matches);

        }

        arsort($matches, SORT_NUMERIC);

        return $matches;

    }



    /**

     * Sends a "HEAD" HTTP command to a server and returns the headers

     * as an associative array.

     *

     * Example output could be:

     * <code>

     *     Array

     *     (

     *         [response_code] => 200          // The HTTP response code

     *         [response] => HTTP/1.1 200 OK   // The full HTTP response string

     *         [Date] => Fri, 11 Jan 2002 01:41:44 GMT

     *         [Server] => Apache/1.3.20 (Unix) PHP/4.1.1

     *         [X-Powered-By] => PHP/4.1.1

     *         [Connection] => close

     *         [Content-Type] => text/html

     *     )

     * </code>

     *

     * @param string  $url     A valid URL, e.g.: http://pear.php.net/credits.php

     * @param integer $timeout Timeout in seconds (default = 10)

     *

     * @return array  Returns associative array of response headers on success

     *                or PEAR error on failure.

     * @static

     * @access public

     * @see HTTP_Client::head()

     * @see HTTP_Request

     */

    function head($url, $timeout = 10)

    {

        $p = parse_url($url);

        if (!isset($p['scheme'])) {

            $p = parse_url(HTTP::absoluteURI($url));

        } elseif ($p['scheme'] != 'http') {

            return HTTP::raiseError('Unsupported protocol: '. $p['scheme']);

        }



        $port = isset($p['port']) ? $p['port'] : 80;



        if (!$fp = @fsockopen($p['host'], $port, $eno, $estr, $timeout)) {

            return HTTP::raiseError("Connection error: $estr ($eno)");

        }



        $path  = !empty($p['path']) ? $p['path'] : '/';

        $path .= !empty($p['query']) ? '?' . $p['query'] : '';



        fputs($fp, "HEAD $path HTTP/1.0\r\n");

        fputs($fp, 'Host: ' . $p['host'] . ':' . $port . "\r\n");

        fputs($fp, "Connection: close\r\n\r\n");



        $response = rtrim(fgets($fp, 4096));

        if (preg_match("|^HTTP/[^\s]*\s(.*?)\s|", $response, $status)) {

            $headers['response_code'] = $status[1];

        }

        $headers['response'] = $response;



        while ($line = fgets($fp, 4096)) {

            if (!trim($line)) {

                break;

            }

            if (($pos = strpos($line, ':')) !== false) {

                $header = substr($line, 0, $pos);

                $value  = trim(substr($line, $pos + 1));



                $headers[$header] = $value;

            }

        }

        fclose($fp);

        return $headers;

    }



    /**

     * This function redirects the client. This is done by issuing

     * a "Location" header and exiting if wanted.  If you set $rfc2616 to true

     * HTTP will output a hypertext note with the location of the redirect.

     *

     * @param string $url     URL where the redirect should go to.

     * @param bool   $exit    Whether to exit immediately after redirection.

     * @param bool   $rfc2616 Wheter to output a hypertext note where we're

     *                        redirecting to (Redirecting to

     *                        <a href="...">...</a>.)

     *

     * @return boolean  Returns TRUE on succes (or exits) or FALSE if headers

     *                  have already been sent.

     * @static

     * @access public

     */

    function redirect($url, $exit = true, $rfc2616 = false)

    {

        if (headers_sent()) {

            return false;

        }



        $url = HTTP::absoluteURI($url);

        header('Location: '. $url);



        if ($rfc2616 && isset($_SERVER['REQUEST_METHOD'])

            && $_SERVER['REQUEST_METHOD'] != 'HEAD') {

            echo '

<p>Redirecting to: <a href="'.str_replace('"', '%22', $url).'">'

                 .htmlspecialchars($url).'</a>.</p>

<script type="text/javascript">

//<![CDATA[

if (location.replace == null) {

    location.replace = location.assign;

}

location.replace("'.str_replace('"', '\\"', $url).'");

// ]]>

</script>';

        }

        if ($exit) {

            exit;

        }

        return true;

    }



    /**

     * This function returns the absolute URI for the partial URL passed.

     * The current scheme (HTTP/HTTPS), host server, port, current script

     * location are used if necessary to resolve any relative URLs.

     *

     * Offsets potentially created by PATH_INFO are taken care of to resolve

     * relative URLs to the current script.

     *

     * You can choose a new protocol while resolving the URI.  This is

     * particularly useful when redirecting a web browser using relative URIs

     * and to switch from HTTP to HTTPS, or vice-versa, at the same time.

     *

     * @param string  $url      Absolute or relative URI the redirect should

     *                          go to.

     * @param string  $protocol Protocol to use when redirecting URIs.

     * @param integer $port     A new port number.

     *

     * @return string  The absolute URI.

     * @author Philippe Jausions <Philippe.Jausions@11abacus.com>

     * @static

     * @access public

     */

    function absoluteURI($url = null, $protocol = null, $port = null)

    {

        // filter CR/LF

        $url = str_replace(array("\r", "\n"), ' ', $url);



        // Mess around protocol and port with already absolute URIs

        if (preg_match('!^([a-z0-9]+)://!i', $url)) {

            if (empty($protocol) && empty($port)) {

                return $url;

            }

            if (!empty($protocol)) {

                $url = $protocol .':'. end($array = explode(':', $url, 2));

            }

            if (!empty($port)) {

                $url = preg_replace('!^(([a-z0-9]+)://[^/:]+)(:[\d]+)?!i',

                                    '\1:'. $port, $url);

            }

            return $url;

        }



        $host = 'localhost';

        if (!empty($_SERVER['HTTP_HOST'])) {

            list($host) = explode(':', $_SERVER['HTTP_HOST']);

        } elseif (!empty($_SERVER['SERVER_NAME'])) {

            list($host) = explode(':', $_SERVER['SERVER_NAME']);

        }



        if (empty($protocol)) {

            if (isset($_SERVER['HTTPS']) && !strcasecmp($_SERVER['HTTPS'], 'on')) {

                $protocol = 'https';

            } else {

                $protocol = 'http';

            }

            if (!isset($port) || $port != intval($port)) {

                $port = isset($_SERVER['SERVER_PORT']) ? $_SERVER['SERVER_PORT'] : 80;

            }

        }



        if ($protocol == 'http' && $port == 80) {

            unset($port);

        }

        if ($protocol == 'https' && $port == 443) {

            unset($port);

        }



        $server = $protocol.'://'.$host.(isset($port) ? ':'.$port : '');



        $uriAll = isset($_SERVER['REQUEST_URI']) ? $_SERVER['REQUEST_URI']

                                                 : $_SERVER['PHP_SELF'];

        if (false !== ($q = strpos($uriAll, '?'))) {

            $uriBase = substr($uriAll, 0, $q);

        } else {

            $uriBase = $uriAll;

        }

        if (!strlen($url) || $url{0} == '#') {

            $url = $uriAll.$url;

        } elseif ($url{0} == '?') {

            $url = $uriBase.$url;

        }

        if ($url{0} == '/') {

            return $server . $url;

        }



        // Adjust for PATH_INFO if needed

        if (isset($_SERVER['PATH_INFO']) && strlen($_SERVER['PATH_INFO'])) {

            $path = dirname(substr($uriBase, 0,

                                   -strlen($_SERVER['PATH_INFO'])));

        } else {

            /**

             * Fixes bug #12672 PHP_SELF ending on / causes incorrect redirects

             *

             * @link http://pear.php.net/bugs/12672

             */

            $path = dirname($uriBase.'-');

        }



        if (substr($path = strtr($path, '\\', '/'), -1) != '/') {

            $path .= '/';

        }



        return $server . $path . $url;

    }



    /**

     * Raise Error

     *

     * Lazy raising of PEAR_Errors.

     *

     * @param mixed   $error Error

     * @param integer $code  Error code

     *

     * @return object  PEAR_Error

     * @static

     * @access protected

     */

    function raiseError($error = null, $code = null)

    {

        include_once 'PEAR.php';

        return PEAR::raiseError($error, $code);

    }

}



?>