Get URL query string parameters - php

Question

What is the "less code needed" way to get parameters from a URL query string which is formatted like the following?
www.mysite.com/category/subcategory?myqueryhash
Output should be: myqueryhash
I am aware of this approach:
www.mysite.com/category/subcategory?q=myquery
<?php
echo $_GET['q']; //Output: myquery
?>

Answer 1

$_SERVER['QUERY_STRING'] contains the data that you are looking for.
DOCUMENTATION
php.net: $_SERVER - Manual

Answer 2

The PHP way to do it is using the function parse_url, which parses a URL and return its components. Including the query string.
Example:
$url = 'www.mysite.com/category/subcategory?myqueryhash';
echo parse_url($url, PHP_URL_QUERY); # output "myqueryhash"
Full documentation here

Answer 3

The function parse_str() automatically reads all query parameters into an array.
For example, if the URL is http://www.example.com/page.php?x=100&y=200, the code
$queries = array();
parse_str($_SERVER['QUERY_STRING'], $queries);
will store parameter values into the $queries array ($queries['x']=100, $queries['y']=200).
Look at documentation of parse_str
EDIT
According to the PHP documentation, parse_str() should only be used with a second parameter (array). Using parse_str($_SERVER['QUERY_STRING']) on this URL will create variables $x and $y, which makes the code vulnerable to attacks such as http://www.example.com/page.php?authenticated=1.

Answer 4

If you want the whole query string:
$_SERVER["QUERY_STRING"]

Answer 5

I will recommend the best answer as:
<?php
echo 'Hello ' . htmlspecialchars($_GET["name"]) . '!';
?>
Assuming the user entered http://example.com/?name=Hannes
The above example will output:
Hello Hannes!

Answer 6

Programming Language: PHP
// Inintialize a URL to the variable
$url = 'https://www.youtube.com/watch?v=qnMxsGeDz90';
// Use parse_url() function to parse the URL
// and return an associative array which contains its various components
$url_components = parse_url($url);
// Use the parse_str() function to parse the
// string passed via the URL
parse_str($url_components['query'], $params);
// Display result
echo 'v parameter value is ' . $params['v'];
This worked for me.

Answer 7

Also if you are looking for current file name along with the query string, you will just need following
basename($_SERVER['REQUEST_URI'])
It would provide you info like following example
file.php?arg1=val&arg2=val
And if you also want full path of file as well starting from root, e.g. /folder/folder2/file.php?arg1=val&arg2=val then just remove basename() function and just use fillowing
$_SERVER['REQUEST_URI']

Answer 8

This code and notation is not mine. Evan K solves a multi value same name query with a custom function ;)
is taken from:
http://php.net/manual/en/function.parse-str.php#76792
Credits go to Evan K.
It bears mentioning that the parse_str builtin does NOT process a query string in the CGI standard way, when it comes to duplicate fields. If multiple fields of the same name exist in a query string, every other web processing language would read them into an array, but PHP silently overwrites them:
<?php
# silently fails to handle multiple values
parse_str('foo=1&foo=2&foo=3');
# the above produces:
$foo = array('foo' => '3');
?>
Instead, PHP uses a non-standards compliant practice of including brackets in fieldnames to achieve the same effect.
<?php
# bizarre php-specific behavior
parse_str('foo[]=1&foo[]=2&foo[]=3');
# the above produces:
$foo = array('foo' => array('1', '2', '3') );
?>
This can be confusing for anyone who's used to the CGI standard, so keep it in mind. As an alternative, I use a "proper" querystring parser function:
<?php
function proper_parse_str($str) {
# result array
$arr = array();
# split on outer delimiter
$pairs = explode('&', $str);
# loop through each pair
foreach ($pairs as $i) {
# split into name and value
list($name,$value) = explode('=', $i, 2);
# if name already exists
if( isset($arr[$name]) ) {
# stick multiple values into an array
if( is_array($arr[$name]) ) {
$arr[$name][] = $value;
}
else {
$arr[$name] = array($arr[$name], $value);
}
}
# otherwise, simply stick it in a scalar
else {
$arr[$name] = $value;
}
}
# return result array
return $arr;
}
$query = proper_parse_str($_SERVER['QUERY_STRING']);
?>

Answer 9

Here is my function to rebuild parts of the REFERRER's query string.
If the calling page already had a query string in its own URL, and you must go back to that page and want to send back some, not all, of that $_GET vars (e.g. a page number).
Example: Referrer's query string was ?foo=1&bar=2&baz=3 calling refererQueryString( 'foo' , 'baz' ) returns foo=1&baz=3":
function refererQueryString(/* var args */) {
//Return empty string if no referer or no $_GET vars in referer available:
if (!isset($_SERVER['HTTP_REFERER']) ||
empty( $_SERVER['HTTP_REFERER']) ||
empty(parse_url($_SERVER['HTTP_REFERER'], PHP_URL_QUERY ))) {
return '';
}
//Get URL query of referer (something like "threadID=7&page=8")
$refererQueryString = parse_url(urldecode($_SERVER['HTTP_REFERER']), PHP_URL_QUERY);
//Which values do you want to extract? (You passed their names as variables.)
$args = func_get_args();
//Get '[key=name]' strings out of referer's URL:
$pairs = explode('&',$refererQueryString);
//String you will return later:
$return = '';
//Analyze retrieved strings and look for the ones of interest:
foreach ($pairs as $pair) {
$keyVal = explode('=',$pair);
$key = &$keyVal[0];
$val = urlencode($keyVal[1]);
//If you passed the name as arg, attach current pair to return string:
if(in_array($key,$args)) {
$return .= '&'. $key . '=' .$val;
}
}
//Here are your returned 'key=value' pairs glued together with "&":
return ltrim($return,'&');
}
//If your referer was 'page.php?foo=1&bar=2&baz=3'
//and you want to header() back to 'page.php?foo=1&baz=3'
//(no 'bar', only foo and baz), then apply:
header('Location: page.php?'.refererQueryString('foo','baz'));

Answer 10

Thanks to #K. Shahzad.
This helps when you want the rewritten query string without any rewrite additions. Let’s say you rewrite the /test/?x=y to index.php?q=test&x=y and you only want the query string.
function get_query_string(){
$arr = explode("?", $_SERVER['REQUEST_URI']);
if (count($arr) == 2){
return "";
}
else{
return "?" . end($arr) . "<br>";
}
}
$query_string = get_query_string();

Answer 11

For getting each node in the URI, you can use function explode() for $_SERVER['REQUEST_URI']. If you want to get strings without knowing if they are passed or not, you may use the function I defined myself to get query parameters from $_REQUEST (as it works both for POST and GET parameters).
function getv($key, $default = '', $data_type = '')
{
$param = (isset($_REQUEST[$key]) ? $_REQUEST[$key] : $default);
if (!is_array($param) && $data_type == 'int') {
$param = intval($param);
}
return $param;
}
There might be some cases when we want to get query parameters converted into Integer type, so I added the third parameter to this function.