Function to remove GET variable with php - php

Question

i have this URI.
http://localhost/index.php?properties&status=av&page=1
i am fetching basename of the URI using following code.
$basename = basename($_SERVER['REQUEST_URI']);
the above code gives me following string.
index.php?properties&status=av&page=1
i would want to remove the last variable from the string i.e &page=1. please note the value for page will not always be 1. keeping this in mind i would want to trim the variable this way.
Trim from the last position of the string till the first delimiter i.e &
Update :
I would like to remove &page=1 from the string, no matter in which position it is on.
how do i do this?

Answer 1

Instead of hacking around with regular expression you should parse the string as an url (what it is)
$string = 'index.php?properties&status=av&page=1';
$parts = parse_url($string);
$queryParams = array();
parse_str($parts['query'], $queryParams);
Now just remove the parameter
unset($queryParams['page']);
and rebuild the url
$queryString = http_build_query($queryParams);
$url = $parts['path'] . '?' . $queryString;

Answer 2

There are many roads that lead to Rome. I'd do it with a RegEx:
$myString = 'index.php?properties&status=av&page=1';
$myNewString = preg_replace("/\&[a-z0-9]+=[0-9]+$/i","",$myString);
if you only want the &page=1-type parameters, the last line would be
$myNewString = preg_replace("/\&page=[0-9]+/i","",$myString);
if you also want to get rid of the possibility that page is the only or first parameter:
$myNewString = preg_replace("/[\&]*page=[0-9]+/i","",$myString);

Answer 3

Thank you guys but i think i have found the better solution, #KingCrunch had suggested a solution i extended and converted it into function. the below function can possibly remove or unset any URI variable without any regex hacks being used. i am posting it as it might help someone.
function unset_uri_var($variable, $uri) {
$parseUri = parse_url($uri);
$arrayUri = array();
parse_str($parseUri['query'], $arrayUri);
unset($arrayUri[$variable]);
$newUri = http_build_query($arrayUri);
$newUri = $parseUri['path'].'?'.$newUri;
return $newUri;
}
now consider the following uri
index.php?properties&status=av&page=1
//To remove properties variable
$url = unset_uri_var('properties', basename($_SERVER['REQUEST_URI']));
//Outputs index.php?page=1&status=av
//To remove page variable
$url = unset_uri_var('page', basename($_SERVER['REQUEST_URI']));
//Outputs index.php?properties=&status=av
hope this helps someone. and thank you #KingKrunch for your solution :)

Answer 4

$pos = strrpos($_SERVER['REQUEST_URI'], '&');
$url = substr($_SERVER['REQUEST_URI'], 0, $pos - 1);
Documentation for strrpos.

Answer 5

Regex that works on every possible situation: /(&|(?<=\?))page=.*?(?=&|$)/. Here's example code:
$regex = '/(&|(?<=\?))page=.*?(?=&|$)/';
$urls = array(
'index.php?properties&status=av&page=1',
'index.php?properties&page=1&status=av',
'index.php?page=1',
);
foreach($urls as $url) {
echo preg_replace($regex, '', $url), "\n";
}
Output:
index.php?properties&status=av
index.php?properties&status=av
index.php?
Regex explanation:
(&|(?<=\?)) -- either match a & or a ?, but if it's a ?, don't put it in the match and just ignore it (you don't want urls like index.php&status=av)
page=.*? -- matches page=[...]
(?=&|$) -- look for a & or the end of the string ($), but don't include them for the replacement (this group helps the previous one find out exactly where to stop matching)

Answer 6

You could use a RegEx (as Chris suggests) but it's not the most efficient solution (lots of overhead using that engine... it's easy to do with some string parsing:
<?php
//$url="http://localhost/index.php?properties&status=av&page=1";
$base=basename($_SERVER['REQUEST_URI']);
echo "Basename yields: $base<br />";
//Find the last ampersand
$lastAmp=strrpos($base,"&");
//Filter, catch no ampersands found
$removeLast=($lastAmp===false?$base:substr($base,0,$lastAmp));
echo "Without Last Parameter: $removeLast<br />";
?>
The trick is, can you guarantee that $page will be stuck on the end? If it is - great, if it isn't... what you asked for may not always solve the problem.