note 108358 modified in reserved.variables.get by sp

From:	sp@php.net	Date:	Sat, 21 Apr 2012 10:30:19 +0000
Subject:	note 108358 modified in reserved.variables.get by sp
References:	1	Groups:	php.notes
Request:	Send a blank email to php-notes+get-187272@lists.php.net to get a copy of this message

A way of removing keys from $_GET - in my opinion - in a more elegant way is by using regular expressions.

I must note, that for better performance, I only use non capturing groupings: (?:... ) 

<?php
/**
 * Remove one or more keys from the URL
 * @author MÃ©szÃ¡ros Lajos GyÃ¶rgy
 * @param $key : Key( string ) or keys( array of strings ) that you want to remove
 */
function remove_key_from_url($key){
	if(is_array($key)) $key = \'(?:\'.implode(\'|\', $key).\')\';
	$url = preg_replace(\'/(?:&|(?<=\\?))\'.$key.\'(?:=[^&]*?)?(?=(?:&|$))/\', \'\', $_SERVER[\'REQUEST_URI\']);
	return preg_replace(\'/(?<=\\?)&|\\?$/\', \'\', $url);
}
?>

So let\'s assume you have the following URL:
something.php?a=12&b=134&c=foo

<?php
echo remove_key_from_url(\'c\');
// will become: something.php?a=12&b=134

echo remove_key_from_url(\'a\');
// will become: something.php?b=134&c=foo
// Note: if key is next to ?, then it will remove the following & sign, so the URL will not become something.php?&b=134&c=foo - ( that is what the 3rd line is for )

echo remove_key_from_url(Array(\'a\', \'b\', \'c\'));
// will become: something.php
// Note: the 3rd line will remove the single ? from the end

// current url here is: /foo/bar/?something&a=3
echo remove_key_from_url(\'something\');
// will become: /foo/bar/?a=3
// Note: the code can handle if no value is assigned to a key
?>

After this, you only need to pass the returned string to a header and then kill the page:

<?php
header('Location:'.remove_key_from_url('logout'));
die();
?>

I need to add, that I didn\'t do any benchmarks upon testing whether is this the faster or doing a bunch of explodes and working with arrays.
Also, I don\'t think it is possible to combine the two regexes into a single one, because the regex in the 3rd line needs to be executed after all key-value removals are done, but if possible, please give me an e-mail, I\'m really interested.

Louis from Hungary --was-- A way of removing keys from $_GET - in my opinion - in a more elegant way is by using regular expressions. I must note, that for better performance, I only use non capturing groupings: (?:... ) <?php /** * Remove one or more keys from the URL * @author MÃ©szÃ¡ros Lajos GyÃ¶rgy * @param $key : Key( string ) or keys( array of strings ) that you want to remove */ function remove_from_url($key){ if(is_array($key)) $key = '(?:'.implode('|', $key).')'; $url = preg_replace('/(?:&|(?<=\?))'.$key.'(?:=[^&]*?)?(?=(?:&|$))/', '', $_SERVER['REQUEST_URI']); return preg_replace('/(?<=\?)&|\?$/', '', $url); } ?> So let's assume you have the following URL: something.php?a=12&b=134&c=foo <?php echo remove_key_from_url('c'); // will become: something.php?a=12&b=134 echo remove_key_from_url('a'); // will become: something.php?b=134&c=foo // Note: if key is next to ?, then it will remove the following & sign, so the URL will not become something.php?&b=134&c=foo - ( that is what the 3rd line is for ) echo remove_key_from_url(Array('a', 'b', 'c')); // will become: something.php // Note: the 3rd line will remove the single ? from the end // current url here is: /foo/bar/?something&a=3 echo remove_key_from_url('something'); // will become: /foo/bar/?a=3 // Note: the code can handle if no value is assigned to a key ?> After this, you only need to pass the returned string to a header and then kill the page: <?php // current URL is admin.php?logout header('Location'.remove_key_from_url('logout')); ?> I need to add, that I didn't do any benchmarks upon testing whether is this the faster or doing a bunch of explodes and working with arrays. Also, I don't think it is possible to combine the two regexes into a single one, because the regex in the 3rd line needs to be executed after all key-value removals are done, but if possible, please give me an e-mail, I'm really interested. Louis from Hungary http://php.net/manual/en/reserved.variables.get.php