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rawurldecode> <http_build_query
Last updated: Fri, 21 Nov 2008

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parse_url

(PHP 4, PHP 5)

parse_urlParse a URL and return its components

Description

mixed parse_url ( string $url [, int $component ] )

This function parses a URL and returns an associative array containing any of the various components of the URL that are present.

This function is not meant to validate the given URL, it only breaks it up into the above listed parts. Partial URLs are also accepted, parse_url() tries its best to parse them correctly.

Parameters

url

The URL to parse. Invalid characters are replaced by _.

component

Specify one of PHP_URL_SCHEME, PHP_URL_HOST, PHP_URL_PORT, PHP_URL_USER, PHP_URL_PASS, PHP_URL_PATH, PHP_URL_QUERY or PHP_URL_FRAGMENT to retrieve just a specific URL component as a string.

Return Values

On seriously malformed URLs, parse_url() may return FALSE and emit a E_WARNING. Otherwise an associative array is returned, whose components may be (at least one):

  • scheme - e.g. http
  • host
  • port
  • user
  • pass
  • path
  • query - after the question mark ?
  • fragment - after the hashmark #

If the component parameter is specified a string is returned instead of an array.

ChangeLog

Version Description
5.1.2 Added the component parameter

Examples

Example #1 A parse_url() example

<?php
$url 
'http://username:password@hostname/path?arg=value#anchor';

print_r(parse_url($url));

echo 
parse_url($urlPHP_URL_PATH);
?>

The above example will output:

Array
(
    [scheme] => http
    [host] => hostname
    [user] => username
    [pass] => password
    [path] => /path
    [query] => arg=value
    [fragment] => anchor
)
/path

Notes

Note: This function doesn't work with relative URLs.

Note: This function is intended specifically for the purpose of parsing URLs and not URIs. However, to comply with PHP's backwards compatibility requirements it makes an exception for the file:// scheme where tripple slashes (file:///...) are allowed. For any other scheme this is invalid.



rawurldecode> <http_build_query
Last updated: Fri, 21 Nov 2008
 
add a note add a note User Contributed Notes
parse_url
pbcomm at gmail dot com
25-Oct-2008 09:55
Modification to the code from:
theoriginalmarksimpson at gmail dot com

Change:
$r .= "(?:(?P<login>\w+):(?P<pass>\w+)@)?";

Replace with:
$r .= "(?:(?P<login>\w+):?(?P<pass>\w+)?@)?";

This will cover the case the only username is present in the url:

http://username@subdomain.domain.com/index.php?arg1=test#anchor
vdklah at hotmail dot com
17-Oct-2008 02:53
Some example that determines the URL port.
When port not specified, it derives it from the scheme.

<?php
function getUrlPort( $urlInfo )
{
    if( isset(
$urlInfo['port']) ) {
       
$port = $urlInfo['port'];
    } else {
// no port specified; get default port
       
if (isset($urlInfo['scheme']) ) {
            switch(
$urlInfo['scheme'] ) {
                case
'http':
                   
$port = 80; // default for http
                   
break;
                case
'https':
                   
$port = 443; // default for https
                   
break;
                case
'ftp':
                   
$port = 21; // default for ftp
                   
break;
                case
'ftps':
                   
$port = 990; // default for ftps
                   
break;
                default:
                   
$port = 0; // error; unsupported scheme
                   
break;
            }
        } else {
           
$port = 0; // error; unknown scheme
       
}
    }
    return
$port;
}

$url = "http://nl3.php.net/manual/en/function.parse-url.php";
$urlInfo = parse_url( $url );
$urlPort = getUrlPort( $urlInfo );
if(
$urlPort !== 0 ) {
    print
'Found URL port: '.$urlPort;
} else {
    print
'ERROR: Could not find port at URL: '.$url;
}
?>
gautam at rogers dot com
15-Oct-2008 11:08
What about using something like this to safely encoding all the values that are passed in the query portion?

Example input:
http://www.example.com/?first=john&last=smith&email=john@smith.com

Result:
http://www.example.com/?first=john&last=smith&email=john%40smith.com

<?php
function safe_url($url) {
 
// Make sure we have a string to work with
 
if(!empty($url)) {
   
// Explode into URL keys
   
$urllist=parse_url($url);

   
// Make sure we have a valid result set and a query field
   
if(is_array($urllist) && isset($urllist["query"])) {
     
// Explode into key/value array
     
$keyvalue_list=explode("&",($urllist["query"]));

     
// Store resulting key/value pairs
     
$keyvalue_result=array();

      foreach(
$keyvalue_list as $key=>$value) {
       
// Explode each individual key/value into an array
       
$keyvalue=explode("=",$value);

       
// Make sure we have a "key=value" array
       
if(count($keyvalue)==2) {
         
// Encode the value portion
         
$keyvalue[1]=urlencode($keyvalue[1]);

         
// Add our key and encoded value into the result
         
array_push($keyvalue_result,implode("=",$keyvalue));
        }
      }

     
// Repopulate our query key with encoded results
     
$urllist["query"]=implode("&",$keyvalue_result);

     
// Build the the final output URL
     
$url=(isset($urllist["scheme"])?$urllist["scheme"]."://":"").
           (isset(
$urllist["user"])?$urllist["user"].":":"").
           (isset(
$urllist["pass"])?$urllist["pass"]."@":"").
           (isset(
$urllist["host"])?$urllist["host"]:"").
           (isset(
$urllist["port"])?":".$urllist["port"]:"").
           (isset(
$urllist["path"])?$urllist["path"]:"").
           (isset(
$urllist["query"])?"?".$urllist["query"]:"").
           (isset(
$urllist["fragment"])?"#".$urllist["fragment"]:"");
    }
  }
 
  return
$url;
}
?>
FredLudd at gmail dot com
03-Oct-2008 11:24
Another shot at trying to find a better parser. I noticed that the laulibrius/theoriginalmarksimpson functions didn't quite handle the URL for the page they were displayed on. For my mirror, ca3, this is
  http://ca3.php.net/manual/en/function.parse-url.php

Run it through the function and it parses to
  scheme => http
  login =>
  pass =>
  host => ca3.php.net
  ip =>
  subdomain => ca3
  domain => php.
  extension => net
  port =>
  path => /manual/en/function.parse
  file => function.parse
that is, the file name gets a bit mangled

Rather than tweak the function's regular expression yet again, I opted to adapt a RegExp that served me well in Javascript:

function j_parseUrl($url) {
  $r  = "(?:([a-z0-9+-._]+)://)?";
  $r .= "(?:";
  $r .=   "(?:((?:[a-z0-9-._~!$&'()*+,;=:]|%[0-9a-f]{2})*)@)?";
  $r .=   "((?:[a-z0-9-._~!$&'()*+,;=]|%[0-9a-f]{2})*)";
  $r .=   "(?::(\d*))?";
  $r .=   "(/(?:[a-z0-9-._~!$&'()*+,;=:@/]|%[0-9a-f]{2})*)?";
  $r .=   "|";
  $r .=   "(/?";
  $r .=     "(?:[a-z0-9-._~!$&'()*+,;=:@]|%[0-9a-f]{2})+";
  $r .=     "(?:[a-z0-9-._~!$&'()*+,;=:@\/]|%[0-9a-f]{2})*";
  $r .=    ")?";
  $r .= ")";
  $r .= "(?:\?((?:[a-z0-9-._~!$&'()*+,;=:\/?@]|%[0-9a-f]{2})*))?";
  $r .= "(?:#((?:[a-z0-9-._~!$&'()*+,;=:\/?@]|%[0-9a-f]{2})*))?";
  preg_match("`$r`i", $url, $match);
  $parts = array(
            "scheme"=>'',
            "userinfo"=>'',
            "authority"=>'',
            "host"=> '',
            "port"=>'',
            "path"=>'',
            "query"=>'',
            "fragment"=>'');
  switch (count ($match)) {
    case 9: $parts['fragment'] = $match[8];
    case 8: $parts['query'] = $match[7];
    case 7: $parts['path'] =  $match[6];
    case 6: $parts['path'] =  $match[5] . $parts['path'];
    case 5: $parts['port'] =  $match[4];
    case 4: $parts['host'] =  $match[3];
    case 3: $parts['userinfo'] =  $match[2];
    case 2: $parts['scheme'] =  $match[1];
  }
  $parts['authority'] = ($parts['userinfo']?$parts['userinfo']."@":"").
                         $parts['host'].
                        ($parts['port']?":".$parts['port']:"");
  return $parts;
}

This function, when fed "http://ca3.php.net/manual/en/function.parse-url.php", returns
  scheme => http
  userinfo =>
  authority => ca3.php.net
  host => ca3.php.net
  port =>
  path => /manual/en/function.parse-url.php
  query =>
  fragment =>
which is somewhat closer to my needs.

But everything should be tested against the two examples provided by RFC3986,

  /* line too long for this site's commnet handler */
  "foo://username:password@example.com:8042".
      "/over/there/index.dtb;type=animal?name=ferret#nose"
and
  "urn:example:animal:ferret:nose"

Here the native function parse_url() performs admirably on that "urn:" example. Mine fails to pick out the path ("example:animal:ferret:nose") and the laulibrius/theoriginalmarksimpson function can't decipher anything there. On the "foo:" example, both my function and parse_url() get it right, while the other examples on this page don't.

The laulibrius/theoriginalmarksimpson function delivers
  scheme => foo
  login => username
  pass => password
  host => example.com
  ip =>
  subdomain =>
  domain => example.
  extension => com
  port => 8042
  path => /over/there/index.dtb
  file => index.dtb

As you can see, the query string ("name=ferret") and fragment ("nose") have dropped off, as well as the parameter ("type=animal").
xellisx
01-Oct-2008 08:37
I need to parse out the query string from the referrer, so I created this function.

<?php
function parse_query($val)
 {
 
/**
   *  Use this function to parse out the query array element from
   *  the output of parse_url().
   */
 
$var  = html_entity_decode($var);
 
$var  = explode('&', $var);
 
$arr  = array();

  foreach(
$var as $val)
   {
   
$x          = explode('=', $val);
   
$arr[$x[0]] = $x[1];
   }
  unset(
$val, $x, $var);
  return
$arr;
 }
?>
ilja at radusch dot com
26-Sep-2008 04:26
Here is an update to the glue_url() function.

It can now handle relative URLs if only 'path' is provided.

<?php
function glue_url($parsed) {
    if (!
is_array($parsed)) {
        return
false;
    }

   
$uri = isset($parsed['scheme']) ? $parsed['scheme'].':'.((strtolower($parsed['scheme']) == 'mailto') ? '' : '//') : '';
   
$uri .= isset($parsed['user']) ? $parsed['user'].(isset($parsed['pass']) ? ':'.$parsed['pass'] : '').'@' : '';
   
$uri .= isset($parsed['host']) ? $parsed['host'] : '';
   
$uri .= isset($parsed['port']) ? ':'.$parsed['port'] : '';

    if (isset(
$parsed['path'])) {
       
$uri .= (substr($parsed['path'], 0, 1) == '/') ?
           
$parsed['path'] : ((!empty($uri) ? '/' : '' ) . $parsed['path']);
    }

   
$uri .= isset($parsed['query']) ? '?'.$parsed['query'] : '';
   
$uri .= isset($parsed['fragment']) ? '#'.$parsed['fragment'] : '';

    return
$uri;
}
?>
nospam at spellingcow dot com
08-Sep-2008 02:03
URL's in the query string of a relative URL will cause a problem

fails:
/page.php?foo=bar&url=http://www.example.com

parses:
http://www.foo.com/page.php?foo=bar&url=http://www.example.com
theoriginalmarksimpson at gmail dot com
05-Sep-2008 12:12
A rehash of code modified by "laulibrius at hotmail dot com".

This also parses urls for hosts that don't have a domain name and just use an IP as the hostname.

The old code would assume that the IP octets were a subdomain.
So the url "http://255.255.255.255/" would return 255.255 as a subdomain of 255.255.

<?php
parseUrl
($url)
   {
  
$r  = "^(?:(?P<scheme>\w+)://)?";
  
$r .= "(?:(?P<login>\w+):(?P<pass>\w+)@)?";

  
$ip="(?:[0-9]{1,3}+\.){3}+[0-9]{1,3}";//ip check
  
$s="(?P<subdomain>[-\w\.]+)\.)?";//subdomain
  
$d="(?P<domain>[-\w]+\.)";//domain
  
$e="(?P<extension>\w+)";//extension

  
$r.="(?P<host>(?(?=".$ip.")(?P<ip>".$ip.")|(?:".$s.$d.$e."))";

  
$r .= "(?::(?P<port>\d+))?";
  
$r .= "(?P<path>[\w/]*/(?P<file>\w+(?:\.\w+)?)?)?";
  
$r .= "(?:\?(?P<arg>[\w=&]+))?";
  
$r .= "(?:#(?P<anchor>\w+))?";
  
$r = "!$r!";   // Delimiters
  
preg_match($r, $url,$out);
   }
?>

If you need to validate the host IP this is easier than using regex.

<?php

$parsed
=parseUrl($url);

if(
$parsed['ip']) {
   if(
long2ip(ip2long($parsed['ip']))==$parsed['ip']){//validates IP
  
echo $parsed['ip']." is a valid host";
   }
   else {
   echo
$parsed['ip']." is not a valid host";
   }
}
?>
marco panichi
23-Aug-2008 01:47
my function catch the url written on the browser by the user and does the same thing of parse_url. but better, I think. I don't like parse_url because it says nothing about elements that it doesn't find in the url. my function instead return an empty string.

<?php
function get_url()
{
   
$arr = array();
   
$uri = $_SERVER['REQUEST_URI'];

   
// query
   
$x = array_pad( explode( '?', $uri ), 2, false );
   
$arr['query'] = ( $x[1] )? $x[1] : '' ;

   
// resource
   
$x         = array_pad( explode( '/', $x[0] ), 2, false );
   
$x_last = array_pop( $x );
    if(
strpos( $x_last, '.' ) === false )
    {
       
$arr['resource'] = '';
       
$x[] = $x_last;
    }
    else
    {
       
$arr['resource'] = $x_last;
    }

   
// path   
   
$arr['path'] = implode( '/', $x );
    if(
substr( $arr['path'], -1 ) !== '/' ) $arr['path'] .= '/';

   
// domain
   
$arr['domain']    = $_SERVER['SERVER_NAME'];

   
// scheme
   
$server_prt        = explode( '/', $_SERVER['SERVER_PROTOCOL'] );
   
$arr['scheme']    = strtolower( $server_prt[0] );

   
// url
   
$arr['url'] = $arr['scheme'].'://'.$arr['domain'].$uri;

    return
$arr;
}
?>

PS: I found working with explode is faster than using preg_match (I tryed with getmicrotime function and 'for' cycles).

PPS: I used array_pad to prevent any notice.
andrewtheartist at hotmail dot com
28-Jun-2008 05:28
Here's the easiest way to get the URL to the path that your script is in (so not the actual script name itself, just the complete URL to the folder it's in)

echo "http://".$_SERVER['HTTP_HOST'].dirname($_SERVER['PHP_SELF']);
Cool Coyote
23-Jun-2008 05:35
based on the "laulibrius at hotmail dot com" function, this work for relatives url only:

<?php
function parseUrl($url) {
$r = "^(?:(?P<path>[\.\w/]*/)?";
$r .= "(?P<file>\w+(?:\.\w+)?)?)\.(?P<extension>\w+)?";
$r .= "(?:\?(?P<arg>[\w=&]+))?";
$r .= "(?:#(?P<anchor>\w+))?";
$r = "!$r!";

preg_match ( $r, $url, $out );
return
$out;
}

print_r(parseUrl("../test/f.aq.php?p=1&v=blabla#X1"));

?>

returns:
Array
(
    [0] => ../test/faq.php?p=1&v=blabla#X1
    [path] => ../test/
    [1] => ../test/
    [file] => faq
    [2] => faq
    [extension] => php
    [3] => php
    [arg] => p=1&v=blabla
    [4] => p=1&v=blabla
    [anchor] => X1
    [5] => X1
)
laulibrius at hotmail dot com
16-Jun-2008 09:31
There was one thing missing in the function dropped by "to1ne at hotmail dot com" when i tried it : domain and subdomain couldn't have a dash "-". So i add it in the regexp and the function looks like this now :

<?php
   
function parseUrl($url) {
       
$r  = "^(?:(?P<scheme>\w+)://)?";
       
$r .= "(?:(?P<login>\w+):(?P<pass>\w+)@)?";
       
$r .= "(?P<host>(?:(?P<subdomain>[-\w\.]+)\.)?" . "(?P<domain>[-\w]+\.(?P<extension>\w+)))";
       
$r .= "(?::(?P<port>\d+))?";
       
$r .= "(?P<path>[\w/]*/(?P<file>\w+(?:\.\w+)?)?)?";
       
$r .= "(?:\?(?P<arg>[\w=&]+))?";
       
$r .= "(?:#(?P<anchor>\w+))?";
       
$r = "!$r!";                                                // Delimiters
      
       
preg_match ( $r, $url, $out );
      
        return
$out;
    }
?>

Btw, thanks for the function, it helps me a lot.
to1ne at hotmail dot com
13-Jun-2008 11:01
Based on the idea of "jbr at ya-right dot com" have I been working on a new function to parse the url:

<?php
function parseUrl($url) {
   
$r  = "^(?:(?P<scheme>\w+)://)?";
   
$r .= "(?:(?P<login>\w+):(?P<pass>\w+)@)?";
   
$r .= "(?P<host>(?:(?P<subdomain>[\w\.]+)\.)?" . "(?P<domain>\w+\.(?P<extension>\w+)))";
   
$r .= "(?::(?P<port>\d+))?";
   
$r .= "(?P<path>[\w/]*/(?P<file>\w+(?:\.\w+)?)?)?";
   
$r .= "(?:\?(?P<arg>[\w=&]+))?";
   
$r .= "(?:#(?P<anchor>\w+))?";
   
$r = "!$r!";                                                // Delimiters
   
   
preg_match ( $r, $url, $out );
   
    return
$out;
}
print_r ( parseUrl ( 'me:you@sub.site.org:29000/pear/validate.html?happy=me&sad=you#url' ) );
?>

This returns:
Array
(
    [0] => me:you@sub.site.org:29000/pear/validate.html?happy=me&sad=you#url
    [scheme] =>
    [1] =>
    [login] => me
    [2] => me
    [pass] => you
    [3] => you
    [host] => sub.site.org
    [4] => sub.site.org
    [subdomain] => sub
    [5] => sub
    [domain] => site.org
    [6] => site.org
    [extension] => org
    [7] => org
    [port] => 29000
    [8] => 29000
    [path] => /pear/validate.html
    [9] => /pear/validate.html
    [file] => validate.html
    [10] => validate.html
    [arg] => happy=me&sad=you
    [11] => happy=me&sad=you
    [anchor] => url
    [12] => url
)

So both named and numbered array keys are possible.

It's quite advanced, but I think it works in any case... Let me know if it doesn't...
jbr at ya-right dot com
02-May-2008 08:24
This function never works the way you think it should...

Example....

<?php

print_r
( parse_url ( 'me:you@sub.site.org/pear/validate.html?happy=me&sad=you#url' ) );

?>

Returns...

Array
(
    [scheme] => me
    [path] => you@sub.site.org/pear/validate.html
    [query] => happy=me&sad=you
    [fragment] => url
)

Here my way of doing parse_url

<?php

function parseUrl ( $url )
{
   
$r  = '!(?:(\w+)://)?(?:(\w+)\:(\w+)@)?([^/:]+)?';
   
$r .= '(?:\:(\d*))?([^#?]+)?(?:\?([^#]+))?(?:#(.+$))?!i';

   
preg_match ( $r, $url, $out );

    return
$out;
}

print_r ( parseUrl ( 'me:you@sub.site.org/pear/validate.html?happy=me&sad=you#url' ) );

?>

Returns...

Array
(
    [0] => me:you@sub.site.org/pear/validate.html?happy=me&sad=you#url
    [1] =>
    [2] => me
    [3] => you
    [4] => sub.site.org
    [5] =>
    [6] => /pear/validate.html
    [7] => happy=me&sad=you
    [8] => url
)

Where as...

out[0] = full url
out[1] = scheme or '' if no scheme was found
out[2] = username or '' if no auth username was found
out[3] = password or '' if no auth password was found
out[4] = domain name or '' if no domain name was found
out[5] = port number or '' if no port number was found
out[6] = path or '' if no path was found
out[7] = query or '' if no query was found
out[8] = fragment or '' if no fragment was found
Nicolas Merlet - admin(at)merletn.org
14-Mar-2008 08:05
Please note that parse_url seems not to produce always the same results when passing non-standard urls.

Eg. I was using this code since 2005 (both under PHP 4.3.10 and PHP 5.2.3) :

<?php

  $p
= parse_url ( 'http://domain.tld/tcp://domain2.tld/dir/file' ) ;

 
$d2 = parse_url ( $p['path'] ) ;

  echo
$d2 // returns '/dir/file'

?>

Of course my example is very specific, as URL is not really correct. But using parse_url was a great trick to split URL easily (without using regular expressions).

Unfortunately under PHP 5.2.0-8 (+etch10), parse_url will fail as it does not accept the slash (/) at the beginning of URL.

Here is a possible patch :

<?php

  $p
= parse_url ( 'http://domain.tld/tcp://domain2.tld/dir/file' ) ;

 
$d2 = parse_url ( substr ( $p['path'] , 1 ) ) ;

  echo
$d2 // returns '/dir/file'

?>

However this last code is not optimized at all, and should be replaced by a regular expression to split URL (so that parse_url would be no longer used).

So you should use parse_url very carefully, and verify that you pass only standard URLs...
Nick Smith
05-Sep-2007 02:32
Note that older versions of PHP (e.g., 4.1) returned an blank string as the path for URLs without any path, such as http://www.php.net

However more recent versions of PHP (e.g., 4.4.7) don't set the path element in the array, so old code will get a PHP warning about an undefined index.
Michael Muryn
27-Aug-2007 08:51
Another update to the glue_url function: applied the "isset" treatment to $parsed['pass'].

<?php
function glue_url($parsed)
{
    if (!
is_array($parsed)) return false;
   
$uri = isset($parsed['scheme']) ? $parsed['scheme'].':'.((strtolower($parsed['scheme']) == 'mailto') ? '' : '//') : '';
   
$uri .= isset($parsed['user']) ? $parsed['user'].(isset($parsed['pass']) ? ':'.$parsed['pass'] : '').'@' : '';
   
$uri .= isset($parsed['host']) ? $parsed['host'] : '';
   
$uri .= isset($parsed['port']) ? ':'.$parsed['port'] : '';
    if(isset(
$parsed['path']))
    {
       
$uri .= (substr($parsed['path'], 0, 1) == '/') ? $parsed['path'] : ('/'.$parsed['path']);
    }
   
$uri .= isset($parsed['query']) ? '?'.$parsed['query'] : '';
   
$uri .= isset($parsed['fragment']) ? '#'.$parsed['fragment'] : '';
    return
$uri;
}
?>
stevenlewis at hotmail dot com
13-Aug-2007 03:08
an update to the glue url function.

you are able to put a host and a path without a slash at the beginning of the path

<?php
function glue_url($parsed)
    {
    if (!
is_array($parsed)) return false;
   
$uri = isset($parsed['scheme']) ? $parsed['scheme'].':'.((strtolower($parsed['scheme']) == 'mailto') ? '':'//'): '';
   
$uri .= isset($parsed['user']) ? $parsed['user'].($parsed['pass']? ':'.$parsed['pass']:'').'@':'';
   
$uri .= isset($parsed['host']) ? $parsed['host'] : '';
   
$uri .= isset($parsed['port']) ? ':'.$parsed['port'] : '';
    if(isset(
$parsed['path']))
        {
       
$uri .= (substr($parsed['path'],0,1) == '/')?$parsed['path']:'/'.$parsed['path'];
        }
   
$uri .= isset($parsed['query']) ? '?'.$parsed['query'] : '';
   
$uri .= isset($parsed['fragment']) ? '#'.$parsed['fragment'] : '';
    return
$uri;
    }
?>
spam at paulisageek dot com
08-Aug-2007 12:05
In reply to adrian,

Thank you very much for your function. There is a small issue with your relative protocol function. You need to remove the // when making the url the path. Here is the new function.

function resolve_url($base, $url) {
        if (!strlen($base)) return $url;
        // Step 2
        if (!strlen($url)) return $base;
        // Step 3
        if (preg_match('!^[a-z]+:!i', $url)) return $url;
        $base = parse_url($base);
        if ($url{0} == "#") {
                // Step 2 (fragment)
                $base['fragment'] = substr($url, 1);
                return unparse_url($base);
        }
        unset($base['fragment']);
        unset($base['query']);
        if (substr($url, 0, 2) == "//") {
                // Step 4
                return unparse_url(array(
                        'scheme'=>$base['scheme'],
                        'path'=>substr($url,2),
                ));
        } else if ($url{0} == "/") {
                // Step 5
                $base['path'] = $url;
        } else {
                // Step 6
                $path = explode('/', $base['path']);
                $url_path = explode('/', $url);
                // Step 6a: drop file from base
                array_pop($path);
                // Step 6b, 6c, 6e: append url while removing "." and ".." from
                // the directory portion
                $end = array_pop($url_path);
                foreach ($url_path as $segment) {
                        if ($segment == '.') {
                                // skip
                        } else if ($segment == '..' && $path && $path[sizeof($path)-1] != '..') {
                                array_pop($path);
                        } else {
                                $path[] = $segment;
                        }
                }
                // Step 6d, 6f: remove "." and ".." from file portion
                if ($end == '.') {
                        $path[] = '';
                } else if ($end == '..' && $path && $path[sizeof($path)-1] != '..') {
                        $path[sizeof($path)-1] = '';
                } else {
                        $path[] = $end;
                }
                // Step 6h
                $base['path'] = join('/', $path);

        }
        // Step 7
        return unparse_url($base);
}
christian at resource-it dot dk
03-Aug-2007 12:57
I searched for an implementation of rfc3986, which is a newer version of rfc 2392. I may find it here : <http://www.chrsen.dk/fundanemt/files/scripter/php/misc/rfc3986.php> - read the rfc at <http://rfc.net/rfc3986.html>
adrian-php at sixfingeredman dot net
25-Jul-2007 02:58
Here's a function which implements resolving a relative URL according to RFC 2396 section 5.2. No doubt there are more efficient implementations, but this one tries to remain close to the standard for clarity. It relies on a function called "unparse_url" to implement section 7, left as an exercise for the reader (or you can substitute the "glue_url" function posted earlier).

<?php
/**
 * Resolve a URL relative to a base path. This happens to work with POSIX
 * filenames as well. This is based on RFC 2396 section 5.2.
 */
function resolve_url($base, $url) {
        if (!
strlen($base)) return $url;
       
// Step 2
       
if (!strlen($url)) return $base;
       
// Step 3
       
if (preg_match('!^[a-z]+:!i', $url)) return $url;
       
$base = parse_url($base);
        if (
$url{0} == "#") {
               
// Step 2 (fragment)
               
$base['fragment'] = substr($url, 1);
                return
unparse_url($base);
        }
        unset(
$base['fragment']);
        unset(
$base['query']);
        if (
substr($url, 0, 2) == "//") {
               
// Step 4
               
return unparse_url(array(
                       
'scheme'=>$base['scheme'],
                       
'path'=>$url,
                ));
        } else if (
$url{0} == "/") {
               
// Step 5
               
$base['path'] = $url;
        } else {
               
// Step 6
               
$path = explode('/', $base['path']);
               
$url_path = explode('/', $url);
               
// Step 6a: drop file from base
               
array_pop($path);
               
// Step 6b, 6c, 6e: append url while removing "." and ".." from
                // the directory portion
               
$end = array_pop($url_path);
                foreach (
$url_path as $segment) {
                        if (
$segment == '.') {
                               
// skip
                       
} else if ($segment == '..' && $path && $path[sizeof($path)-1] != '..') {
                               
array_pop($path);
                        } else {
                               
$path[] = $segment;
                        }
                }
               
// Step 6d, 6f: remove "." and ".." from file portion
               
if ($end == '.') {
                       
$path[] = '';
                } else if (
$end == '..' && $path && $path[sizeof($path)-1] != '..') {
                       
$path[sizeof($path)-1] = '';
                } else {
                       
$path[] = $end;
                }
               
// Step 6h
               
$base['path'] = join('/', $path);

        }
       
// Step 7
       
return unparse_url($base);
}
?>
Antti Haapala
17-Jul-2007 01:42
Actually the behaviour noticed by the previous poster is quite correct. When the URI scheme is not present, it is plain wrong to assume that something starting with www. is a domain name, and that the scheme is HTTP. Internet Explorer does it that way, sure, but it does not make it any more correct. The documentation says that the function tries to decode the URL as well as it can, and the only sensible and standards-compliant way to decode such URL is to expect it to be a relative URI.
Elliott Brueggeman
03-Jun-2007 03:59
Note that if you pass this function a url without a scheme (www.php.net, as opposed to http://www.php.net), the function will incorrectly parse the results. In my test case it returned the domain under the ['path'] element and nothing in the ['host'] element.
Marc-Antoine Ross
14-Mar-2007 09:10
Do not look for the fragment in $_SERVER['QUERY_STRING'], you will not find it. You should read the fragment in JavaScript for example.
alistair at 21degrees dot com dot au
23-Oct-2006 07:21
Heres a simple function to add the $component option in for PHP4. Haven't done exhaustive testing, but should work ok.

<?php

   
## Defines only available in PHP 5, created for PHP4
   
if(!defined('PHP_URL_SCHEME')) define('PHP_URL_SCHEME', 1);
    if(!
defined('PHP_URL_HOST')) define('PHP_URL_HOST', 2);
    if(!
defined('PHP_URL_PORT')) define('PHP_URL_PORT', 3);
    if(!
defined('PHP_URL_USER')) define('PHP_URL_USER', 4);
    if(!
defined('PHP_URL_PASS')) define('PHP_URL_PASS', 5);
    if(!
defined('PHP_URL_PATH')) define('PHP_URL_PATH', 6);
    if(!
defined('PHP_URL_QUERY')) define('PHP_URL_QUERY', 7);                       
    if(!
defined('PHP_URL_FRAGMENT')) define('PHP_URL_FRAGMENT', 8);   
   
    function
parse_url_compat($url, $component=NULL){
       
        if(!
$component) return parse_url($url);
       
       
## PHP 5
       
if(phpversion() >= 5)
            return
parse_url($url, $component);

       
## PHP 4
       
$bits = parse_url($url);
       
        switch(
$component){
            case
PHP_URL_SCHEME: return $bits['scheme'];
            case
PHP_URL_HOST: return $bits['host'];
            case
PHP_URL_PORT: return $bits['port'];
            case
PHP_URL_USER: return $bits['user'];
            case
PHP_URL_PASS: return $bits['pass'];
            case
PHP_URL_PATH: return $bits['path'];
            case
PHP_URL_QUERY: return $bits['query'];
            case
PHP_URL_FRAGMENT: return $bits['fragment'];
        }
       
    }

?>
dawalama at gmail dot com
04-Oct-2006 09:48
With few modifications

    /**
     * source: http://us2.php.net/manual/en/function.parse-url.php#60237
     * Edit the Query portion of an url
     *
     * @param    string    $action    ethier a "+" or a "-" depending on what action you want to perform
     * @param    mixed    $var    array (+) or string (-)
     * @param    string    $uri    the URL to use. if this is left out, it uses $_SERVER['PHP_SELF']
     * @version      1.0.0
     */
    function change_query($action, $var = NULL, $uri = NULL) {

               if (($action == "+" && !is_array($var)) || ($action == "-" && $var == "") || $var == NULL) {
                       return FALSE;
               }

               if (is_null($uri)) { //Piece together uri string
                       $beginning = $_SERVER['PHP_SELF'];
                       $ending = (isset ($_SERVER['QUERY_STRING'])) ? $_SERVER['QUERY_STRING'] : '';
               } else {
                       $qstart = strpos($uri, '?');
                       if ($qstart === false) {
                               $beginning = $uri; //$ending is '' anyway
                               $ending = "";
                       } else {
                               $beginning = substr($uri, 0, $qstart);
                               $ending = substr($uri, $qstart);
                       }
               }

               $vals = array ();
               $ending = str_replace('?', '', $ending);
               parse_str($ending, $vals);

               switch ($action) {
                       case '+' :
                               $vals[$var[0]] = $var[1];
                               break;
                       case '-' :
                               if (isset ($vals[$var])) {
                                       unset ($vals[$var]);
                               }
                               break;
                       default :
                               break;
               }

               $params = array();
               foreach ($vals as $k => $value) {
                       $params[] = $k."=".urlencode($value);
               }
               $result = $beginning . (count($params) ? '?' . implode("&", $params) : '');
               return $result;
       }
kjensen at nospam dot iaff106 dot com
26-Sep-2006 04:21
Here is a simple extended version of ParseURL(). 
I needed to make a link that will be saved off site but point to different file
than the one creating the link.

So I needed to get the path without the file name so I could change the
 file name.

Here it is:

<?php
function ParseURLplus($url){
$URLpcs = (parse_url($url));
$PathPcs = explode("/",$URLpcs['path']);
$URLpcs['file'] = end($PathPcs);
unset(
$PathPcs[key($PathPcs)]);
$URLpcs['dir'] = implode("/",$PathPcs);
return (
$URLpcs);
}

$url = 'http://username:password@hostname/path/directory/file.php?arg=
value#anchor'
;

$URLpcs = ParseURLplus($url);

print_r($URLpcs);
?>

Now I can change the $URLpcs['file'] and then glue itback together to make
 a new url.
corgilabs at SPAM_NO_THANK_YOUgmail dot com
13-Jul-2006 11:59
I hope this is helpful! Cheers!
-eo

<?

# Author: Eric O
# Date: July 13, 2006
# Go Zizou!! :O)

# Creating Automatic Self-Redirect To Secure Version
# of Website as Seen on Paypal and other secure sites
# Changes HTTP to HTTPS

#gets the URI of the script
$url =  $_SERVER['SCRIPT_URI'];

#chops URI into bits BORK BORK BORK
$chopped = parse_url($url);

#HOST and PATH portions of your final destination
$destination = $chopped[host].$chopped[path];

#if you are not HTTPS, then do something about it
if($chopped[scheme] != "https"){

#forwards to HTTP version of URI with secure certificate
header("Location: https://$destination");

exit();

}

?>
php dot net at NOSPAM dot juamei dot com
09-May-2006 04:18
Modfied version of glue_url to avoid error messages if the error_reporting is set high.

function glue_url($parsed)
{
    if (! is_array($parsed)) return false;
        $uri = isset($parsed['scheme']) ? $parsed['scheme'].':'.((strtolower($parsed['scheme']) == 'mailto') ? '':'//'): '';
        $uri .= isset($parsed['user']) ? $parsed['user'].($parsed['pass']? ':'.$parsed['pass']:'').'@':'';
        $uri .= isset($parsed['host']) ? $parsed['host'] : '';
        $uri .= isset($parsed['port']) ? ':'.$parsed['port'] : '';
        $uri .= isset($parsed['path']) ? $parsed['path'] : '';
        $uri .= isset($parsed['query']) ? '?'.$parsed['query'] : '';
        $uri .= isset($parsed['fragment']) ? '#'.$parsed['fragment'] : '';
    return $uri;
}
TheShadow
30-Dec-2004 12:36
You may want to check out the PEAR NET_URL class. It provides easy means to manipulate URL strings.

http://pear.php.net/package/Net_URL
matt at cryptography dot com
09-May-2004 01:36
Modified version of glue_url()
Cox's,Anonimous fucntion

<?php
function glue_url($parsed) {
   if (!
is_array($parsed)) return false;
      
$uri = $parsed['scheme'] ? $parsed['scheme'].':'.((strtolower($parsed['scheme']) == 'mailto') ? '':'//'): '';
      
$uri .= $parsed['user'] ? $parsed['user'].($parsed['pass']? ':'.$parsed['pass']:'').'@':'';
      
$uri .= $parsed['host'] ? $parsed['host'] : '';
      
$uri .= $parsed['port'] ? ':'.$parsed['port'] : '';
      
$uri .= $parsed['path'] ? $parsed['path'] : '';
      
$uri .= $parsed['query'] ? '?'.$parsed['query'] : '';
      
$uri .= $parsed['fragment'