Strip off specific parameter from URL's querystring - php

Question

I have some links in a Powerpoint presentation, and for some reason, when those links get clicked, it adds a return parameter to the URL. Well, that return parameter is causing my Joomla site's MVC pattern to get bungled.
What's an efficient way to strip off this return parameter using PHP?
Example:
http://mydomain.example/index.php?id=115&Itemid=283&return=aHR0cDovL2NvbW11bml0

Answer 1

The safest "correct" method would be:
Parse the url into an array with parse_url()
Extract the query portion, decompose that into an array using parse_str()
Delete the query parameters you want by unset() them from the array
Rebuild the original url using http_build_query()
Quick and dirty is to use a string search/replace and/or regex to kill off the value.

Answer 2

In a different thread Justin suggests that the fastest way is to use strtok()
$url = strtok($url, '?');
See his full answer with speed tests as well here: https://stackoverflow.com/a/1251650/452515

Answer 3

This is to complement Marc B's answer with an example, while it may look quite long, it's a safe way to remove a parameter. In this example we remove page_number
<?php
$x = 'http://url.example/search/?location=london&page_number=1';
$parsed = parse_url($x);
$query = $parsed['query'];
parse_str($query, $params);
unset($params['page_number']);
$string = http_build_query($params);
var_dump($string);

Answer 4

function removeParam($url, $param) {
$url = preg_replace('/(&|\?)'.preg_quote($param).'=[^&]*$/', '', $url);
$url = preg_replace('/(&|\?)'.preg_quote($param).'=[^&]*&/', '$1', $url);
return $url;
}

Answer 5

parse_str($queryString, $vars);
unset($vars['return']);
$queryString = http_build_query($vars);
parse_str parses a query string, http_build_query creates a query string.

Answer 6

Procedural Implementation of Marc B's Answer after refining Sergey Telshevsky's Answer.
function strip_param_from_url($url, $param)
{
$base_url = strtok($url, '?'); // Get the base URL
$parsed_url = parse_url($url); // Parse it
// Add missing {
if(array_key_exists('query',$parsed_url)) { // Only execute if there are parameters
$query = $parsed_url['query']; // Get the query string
parse_str($query, $parameters); // Convert Parameters into array
unset($parameters[$param]); // Delete the one you want
$new_query = http_build_query($parameters); // Rebuilt query string
$url =$base_url.'?'.$new_query; // Finally URL is ready
}
return $url;
}
// Usage
echo strip_param_from_url( 'http://url.example/search/?location=london&page_number=1', 'location' )

Answer 7

You could do a preg_replace like:
$new_url = preg_replace('/&?return=[^&]*/', '', $old_url);

Answer 8

Here is the actual code for what's described above as the "the safest 'correct' method"...
function reduce_query($uri = '') {
$kill_params = array('gclid');
$uri_array = parse_url($uri);
if (isset($uri_array['query'])) {
// Do the chopping.
$params = array();
foreach (explode('&', $uri_array['query']) as $param) {
$item = explode('=', $param);
if (!in_array($item[0], $kill_params)) {
$params[$item[0]] = isset($item[1]) ? $item[1] : '';
}
}
// Sort the parameter array to maximize cache hits.
ksort($params);
// Build new URL (no hosts, domains, or fragments involved).
$new_uri = '';
if ($uri_array['path']) {
$new_uri = $uri_array['path'];
}
if (count($params) > 0) {
// Wish there was a more elegant option.
$new_uri .= '?' . urldecode(http_build_query($params));
}
return $new_uri;
}
return $uri;
}
$_SERVER['REQUEST_URI'] = reduce_query($_SERVER['REQUEST_URI']);
However, since this will likely exist prior to the bootstrap of your application, you should probably put it into an anonymous function. Like this...
call_user_func(function($uri) {
$kill_params = array('gclid');
$uri_array = parse_url($uri);
if (isset($uri_array['query'])) {
// Do the chopping.
$params = array();
foreach (explode('&', $uri_array['query']) as $param) {
$item = explode('=', $param);
if (!in_array($item[0], $kill_params)) {
$params[$item[0]] = isset($item[1]) ? $item[1] : '';
}
}
// Sort the parameter array to maximize cache hits.
ksort($params);
// Build new URL (no hosts, domains, or fragments involved).
$new_uri = '';
if ($uri_array['path']) {
$new_uri = $uri_array['path'];
}
if (count($params) > 0) {
// Wish there was a more elegant option.
$new_uri .= '?' . urldecode(http_build_query($params));
}
// Update server variable.
$_SERVER['REQUEST_URI'] = $new_uri;
}
}, $_SERVER['REQUEST_URI']);
NOTE: Updated with urldecode() to avoid double encoding via http_build_query() function.
NOTE: Updated with ksort() to allow params with no value without an error.

Answer 9

This one of many ways, not tested, but should work.
$link = 'http://mydomain.example/index.php?id=115&Itemid=283&return=aHR0cDovL2NvbW11bml0';
$linkParts = explode('&return=', $link);
$link = $linkParts[0];

Answer 10

Wow, there are a lot of examples here. I am providing one that does some error handling. It rebuilds and returns the entire URL with the query-string-param-to-be-removed, removed. It also provides a bonus function that builds the current URL on the fly. Tested, works!
Credit to Mark B for the steps. This is a complete solution to tpow's "strip off this return parameter" original question -- might be handy for beginners, trying to avoid PHP gotchas. :-)
<?php
function currenturl_without_queryparam( $queryparamkey ) {
$current_url = current_url();
$parsed_url = parse_url( $current_url );
if( array_key_exists( 'query', $parsed_url )) {
$query_portion = $parsed_url['query'];
} else {
return $current_url;
}
parse_str( $query_portion, $query_array );
if( array_key_exists( $queryparamkey , $query_array ) ) {
unset( $query_array[$queryparamkey] );
$q = ( count( $query_array ) === 0 ) ? '' : '?';
return $parsed_url['scheme'] . '://' . $parsed_url['host'] . $parsed_url['path'] . $q . http_build_query( $query_array );
} else {
return $current_url;
}
}
function current_url() {
$current_url = 'http' . (isset($_SERVER['HTTPS']) ? 's' : '') . '://' . "{$_SERVER['HTTP_HOST']}{$_SERVER['REQUEST_URI']}";
return $current_url;
}
echo currenturl_without_queryparam( 'key' );
?>

Answer 11

$var = preg_replace( "/return=[^&]+/", "", $var );
$var = preg_replace( "/&{2,}/", "&", $var );
Second line will just replace && to &

Answer 12

very simple
$link = "http://example.com/index.php?id=115&Itemid=283&return=aHR0cDovL2NvbW11bml0"
echo substr($link, 0, strpos($link, "return") - 1);
//output : http://example.com/index.php?id=115&Itemid=283

Answer 13

#MarcB mentioned that it is dirty to use regex to remove an url parameter. And yes it is, because it's not as easy as it looks:
$urls = array(
'example.com/?foo=bar',
'example.com/?bar=foo&foo=bar',
'example.com/?foo=bar&bar=foo',
);
echo 'Original' . PHP_EOL;
foreach ($urls as $url) {
echo $url . PHP_EOL;
}
echo PHP_EOL . '#AaronHathaway' . PHP_EOL;
foreach ($urls as $url) {
echo preg_replace('#&?foo=[^&]*#', null, $url) . PHP_EOL;
}
echo PHP_EOL . '#SergeS' . PHP_EOL;
foreach ($urls as $url) {
echo preg_replace( "/&{2,}/", "&", preg_replace( "/foo=[^&]+/", "", $url)) . PHP_EOL;
}
echo PHP_EOL . '#Justin' . PHP_EOL;
foreach ($urls as $url) {
echo preg_replace('/([?&])foo=[^&]+(&|$)/', '$1', $url) . PHP_EOL;
}
echo PHP_EOL . '#kraftb' . PHP_EOL;
foreach ($urls as $url) {
echo preg_replace('/(&|\?)foo=[^&]*&/', '$1', preg_replace('/(&|\?)foo=[^&]*$/', '', $url)) . PHP_EOL;
}
echo PHP_EOL . 'My version' . PHP_EOL;
foreach ($urls as $url) {
echo str_replace('/&', '/?', preg_replace('#[&?]foo=[^&]*#', null, $url)) . PHP_EOL;
}
returns:
Original
example.com/?foo=bar
example.com/?bar=foo&foo=bar
example.com/?foo=bar&bar=foo
#AaronHathaway
example.com/?
example.com/?bar=foo
example.com/?&bar=foo
#SergeS
example.com/?
example.com/?bar=foo&
example.com/?&bar=foo
#Justin
example.com/?
example.com/?bar=foo&
example.com/?bar=foo
#kraftb
example.com/
example.com/?bar=foo
example.com/?bar=foo
My version
example.com/
example.com/?bar=foo
example.com/?bar=foo
As you can see only #kraftb posted a correct answer using regex and my version is a little bit smaller.

Answer 14

Remove Get Parameters From Current Page
<?php
$url_dir=$_SERVER['REQUEST_URI'];
$url_dir_no_get_param= explode("?",$url_dir)[0];
echo $_SERVER['HTTP_HOST'].$url_dir_no_get_param;

Answer 15

This should do it:
public function removeQueryParam(string $url, string $param): string
{
$parsedUrl = parse_url($url);
if (isset($parsedUrl[$param])) {
$baseUrl = strtok($url, '?');
parse_str(parse_url($url)['query'], $query);
unset($query[$param]);
return sprintf('%s?%s',
$baseUrl,
http_build_query($query)
);
}
return $url;
}

Answer 16

Simple solution that will work for every url
With this solution $url format or parameter position doesn't matter, as an example I added another parameter and anchor at the end of $url:
https://example.com/index.php?id=115&Itemid=283&return=aHR0cDovL2NvbW11bml0&bonus=test#test2
Here is the simple solution:
$url = 'https://example.com/index.php?id=115&Itemid=283&return=aHR0cDovL2NvbW11bml0&bonus=test#test2';
$url_query_stirng = parse_url($url, PHP_URL_QUERY);
parse_str( $url_query_stirng, $url_parsed_query );
unset($url_parsed_query['return']);
$url = str_replace( $url_query_stirng, http_build_query( $url_parsed_query ), $url );
echo $url;
Final result for $url string is:
https://example.com/index.php?id=115&Itemid=283&bonus=test#test2

Answer 17

Some of the examples posted are so extensive. This is what I use on my projects.
function removeQueryParameter($url, $param){
list($baseUrl, $urlQuery) = explode('?', $url, 2);
parse_str($urlQuery, $urlQueryArr);
unset($urlQueryArr[$param]);
if(count($urlQueryArr))
return $baseUrl.'?'.http_build_query($urlQueryArr);
else
return $baseUrl;
}

Answer 18

function remove_attribute($url,$attribute)
{
$url=explode('?',$url);
$new_parameters=false;
if(isset($url[1]))
{
$params=explode('&',$url[1]);
$new_parameters=ra($params,$attribute);
}
$construct_parameters=($new_parameters && $new_parameters!='' ) ? ('?'.$new_parameters):'';
return $new_url=$url[0].$construct_parameters;
}
function ra($params,$attr)
{ $attr=$attr.'=';
$new_params=array();
for($i=0;$i<count($params);$i++)
{
$pos=strpos($params[$i],$attr);
if($pos===false)
$new_params[]=$params[$i];
}
if(count($new_params)>0)
return implode('&',$new_params);
else
return false;
}
//just copy the above code and just call this function like this to get new url without particular parameter
echo remove_attribute($url,'delete_params'); // gives new url without that parameter

Answer 19

I know this is an old question but if you only want to remove one or few named url parameter you can use this function:
function RemoveGet_Regex($variable, $rewritten_url): string {
$rewritten_url = preg_replace("/(\?)$/", "", preg_replace("/\?&/", "?", preg_replace("/((?<=\?)|&){$variable}=[\w]*/i", "", $rewritten_url)));
return $rewritten_url;
}
function RemoveGet($name): void {
$rewritten_url = "https://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
if(is_array($name)) {
for($i = 0; $i < count($name); $i++) {
$rewritten_url = RemoveGet_Regex($name[$i], $rewritten_url);
$is_set[] = isset($_GET[$name[$i]]);
}
$array_filtered = array_filter($is_set);
if (!empty($array_filtered)) {
header("Location: ".$rewritten_url);
}
}
else {
$rewritten_url = RemoveGet_Regex($name, $rewritten_url);
if(isset($_GET[$name])) {
header("Location: ".$rewritten_url);
}
}
}
In the first function preg_replace("/((?<=\?)|&){$variable}=[\w]*/i", "", $rewritten_url) will remove the get parameter, and the others will tidy it up. The second function will then redirect.
RemoveGet("id"); will remove the id=whatever from the url. The function can also work with arrays. For your example,
Remove(array("id","Item","return"));

Answer 20

To strip any parameter from the url using PHP script you need to follow this script:
function getNewArray($array,$k){
$dataArray = $array;
unset($array[$k]);
$dataArray = $array;
return $dataArray;
}
function getFullURL(){
return (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] === 'on' ? "https" : "http") . "://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
}
$url = getFullURL();
$url_components = parse_url($url);
// Use parse_str() function to parse the
// string passed via URL
parse_str($url_components['query'], $params);
print_r($params);
<ul>
<?php foreach($params as $k=>$v){?>
<?php
$newArray = getNewArray($params,$k);
$parameters = http_build_query($newArray);
$newURL = $_SERVER['PHP_SELF']."?".$parameters;
?>
<li><?=$v;?> X
<?php }?>
</ul>

Answer 21

here is functions optimized for speed. But this functions DO NOT remove arrays like a[]=x&a[1]bb=y&a[2]=z by array name.
function removeQueryParam($query, $param)
{
$quoted_param = preg_quote($param, '/');
$pattern = "/(^$quoted_param=[^&]*&?)|(&$quoted_param=[^&]*)/";
return preg_replace($pattern, '', $query);
}
function removeQueryParams($query, array $params)
{
if ($params)
{
$pattern = '/';
foreach ($params as $param)
{
$quoted_param = preg_quote($param, '/');
$pattern .= "(^$quoted_param=[^&]*&?)|(&$quoted_param=[^&]*)|";
}
$pattern[-1] = '/';
return preg_replace($pattern, '', $query);
}
return $query;
}

Answer 22

<? if(isset($_GET['i'])){unset($_GET['i']); header('location:/');} ?>
This will remove the 'i' parameter from the URL. Change the 'i's to whatever you need.