Using an expression to remove part of a string - php

Question

This is probably simple however I am not the best with expressions..
I am trying to get the following string from..
http://www.yoursite.com/offers/838?&SITEID=2172
to this.. using an expression that will remove the ?&SITEID and the dynamic id which will vary
http://www.yoursite.com/offers/838
Can anyone suggest the best/simplest method to do this?

Answer 1

Check this function:
$str = 'http://www.yoursite.com/offers/838?&SITEID=2172';
function remove_query_arg($var, $url = NULL){
if(!$url){
$url = $_SERVER['REQUEST_URI'];
}
$parsed_url = parse_url($url);
$query_vars = explode('&', $parsed_url['query']);
foreach($query_vars as $key => $value){
$query_vars[$key] = explode('=', $query_vars[$key]);
$query_variables[$query_vars[$key][0]] = $query_vars[$key][1];
}
if(is_array($var)){
foreach($var as $value){
unset($query_variables[$value]);
}
}
elseif(is_string($var)){
unset($query_variables[$var]);
}
$query_vars = array();
foreach($query_variables as $key => $value){
$query_vars[] = $key.($value !== NULL || !empty($value) ? '='.$value : '');
}
$query_str = '';
$query_str = implode('&',$query_vars);
return (isset($parsed_url['scheme']) && !empty($parsed_url['scheme']) ? $parsed_url['scheme'].'://' : '').$parsed_url['host'].(isset($parsed_url['path']) && !empty($parsed_url['path']) ? $parsed_url['path'] : '').(!empty($query_str) ? '?'.$query_str : '');
}
echo remove_query_arg('SITEID', $str);

Answer 2

This is a URL, so parse it as one, with parse_url().
$url = "http://www.yoursite.com/offers/838?&SITEID=2172";
$parts = parse_url($url);
$url = $parts["scheme"] . "://" . $parts["host"] . $parts["path"];

Answer 3

Using explode function returns an array
$url=http://www.yoursite.com/offers/838?&SITEID=2172
$result=explode('?',$url)
print_r($result);
output
array
{
[0]=>http://www.yoursite.com/offers/838
[1]=>?&SITEID=2172
}

Answer 4

A valid URL only has one ? so you can just use explode to break it into 2 parts
$url = "http://www.yoursite.com/offers/838?&SITEID=2172";
list($path, $query) = explode("?", $url, "2");
var_dump($path);
Output
string 'http://www.yoursite.com/offers/838' (length=34)

Answer 5

$url = "http://www.yoursite.com/offers/838?&SITEID=2172";
$str = substr($url, strpos($url, 0, "?&SITEID"));
// $str results in "http://www.yoursite.com/offers/838"

Answer 6

If you want to keep the part before the ? you can search
^(.+?)(\?&SITEID|$)
and replace with
$1
You search non greedily from the beginning of the line ^ to the first ?&SITEID and leave out the rest. If no ?&SITEID is found you get the entire line by arriving at the end of the string with $
| is the OR operator that tells the regex "Stop at the first ?&SITEID or at the end of the string"
EDIT:
After the comment where you explain your need to keep the rest of the querystring I suggest you a different approach: find
&?SITEID=[^&\s]+
being
&? an optional & at the beginning of the string
SITEID= the string you are looking for followed by
[^&\s]+ any number of non&, nonspace character
and remove it from the string. However, being this the case, I'd go with a non-regex, url-specific approach like suggested in the other answers.