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$_GET -- $HTTP_GET_VARS [veraltet, nicht empfohlen] — HTTP GET-Variablen
Ein assoziatives Array von Variablen, die dem aktuellen Skript mittels der URL-Parameter übergeben werden.
$HTTP_GET_VARS enthält anfangs die selben Informationen, ist aber kein Superglobal. (Beachten Sie, dass $HTTP_GET_VARS und $_GET unterschiedliche Variablen sind und von PHP daher entsprechend behandelt werden.)
| Version | Beschreibung |
|---|---|
| 4.1.0 | Einführung von $_GET als Ablösung des bis dahin existierenden $HTTP_GET_VARS. |
Beispiel #1 $_GET-Beispiel
<?php
echo 'Hello ' . htmlspecialchars($_GET["name"]) . '!';
?>
Angenommen, der Benutzer gab ein http://example.com/?name=Hannes
Das oben gezeigte Beispiel erzeugt eine ähnliche Ausgabe wie:
Hello Hannes!
Hinweis:
Dies ist eine 'Superglobale' oder automatisch globale Variable. Dies bedeutet, dass sie innerhalb des Skripts in jedem Geltungsbereich sichtbar ist. Es ist nicht nötig, sie mit global $variable bekannt zu machen, um aus Funktionen oder Methoden darauf zuzugreifen.
Hinweis:
Die GET-Variablen werden automatisch mit urldecode() behandelt.
Please note that PHP setups with the suhosin patch installed will have a default limit of 512 characters for get parameters. Although bad practice, most browsers (including IE) supports URLs up to around 2000 characters, while Apache has a default of 8000.
To add support for long parameters with suhosin, add
suhosin.get.max_value_length = <limit> in php.ini
Just a note, because I didn't know for sure until I tested it.
If you have a query string that contains a parameter but no value (not even an equals sign), like so:
http://path/to/script.php?a
The following script is a good test to determine how a is valued:
<pre>
<?php
print_r($_GET);
if($_GET["a"] === "") echo "a is an empty string\n";
if($_GET["a"] === false) echo "a is false\n";
if($_GET["a"] === null) echo "a is null\n";
if(isset($_GET["a"])) echo "a is set\n";
if(!empty($_GET["a"])) echo "a is not empty";
?>
</pre>
I tested this with script.php?a, and it returned:
a is an empty string
a is set
So note that a parameter with no value associated with, even without an equals sign, is considered to be an empty string (""), isset() returns true for it, and it is considered empty, but not false or null. Seems obvious after the first test, but I just had to make sure.
Of course, if I do not include it in my browser query, the script returns
Array
(
)
a is null
This Function will help you to manage your GET parameters to facilitate coding and prevent duplication. This is a basic version but it can be easily extended.
<?php
// Author: Alberto Lepe (www.alepe.com)
/* Process $_GET to preserve user custom parameters
* the arguments is a list of URL parameters that should be removed/changed from URL
* for example:
*
* URL = "index.php?s=1&fi=2&m=4&p=3
*
* if called: fixGet("s"); the result has to be: ?fi=2&m=4&p=3
* if called: fixGet("s&m"); the result has to be: ?fi=2&p=3
* if called: fixGet("s=4"); the result has to be: ?s=4&fi=2&m=4&p=3
* if called: fixGet("s=2&m"); the result has to be: ?s=2&fi=2&p=3
* if called: fixGet("s=&m=3"); the result has to be: ?s=&fi=2&m=3&p=3
* if called: fixGet("s=2&m="); the result has to be: ?s=2&fi=2&m=&p=3
* Special: when it ends with a =":" its to leave it open at the end
* (just first occurrence) to facilitate concatenation:
* if called: fixGet("s=2&m:"); the result has to be: ?s=2&fi=2&p=3&m
* if called: fixGet("s=2&m:="); the result has to be: ?s=2&fi=2&p=3&m=
*
* Usage with HTML (using the URL example above and $id = 99):
*
* <a href="index.php<?php echo fixGet('m=2&s&fi:=').$id ?>" >Link</a>
* Explanation: change "m" to 2, delete "s" and "fi" gets the $id value. ("p" is kept as it is not specified)
* will output: <a href='index.php?m=2&p=3&fi=99'>Link</a>
*/
public function fixGet($args) {
if(count($_GET) > 0) {
if(!empty($args)) {
$lastkey = "";
$pairs = explode("&",$args);
foreach($pairs as $pair) {
if(strpos($pair,":") !== false) {
list($key,$value) = explode(":",$pair);
unset($_GET[$key]);
$lastkey = "&$key$value";
} elseif(strpos($pair,"=") === false)
unset($_GET[$pair]);
else {
list($key, $value) = explode("=",$pair);
$_GET[$key] = $value;
}
}
}
return "?".((count($_GET) > 0)?http_build_query($_GET).$lastkey:"");
}
?>
To test, copy+paste the following code into testFixGet.php
<?php
/*
* Unit Test for fixGet()
*/
$cases = array (
0 => array("s" => 1, "fi" => 2, "m" => 4, "p" => 3),
1 => array("s" => "", "fi" => "", "m" => 4, "p" => 3),
);
$test[0] = array(
"s" => "fi=2&m=4&p=3",
"s&m" => "fi=2&p=3",
"s=4" => "s=4&fi=2&m=4&p=3",
"s=2&m" => "s=2&fi=2&p=3",
"s=&m=3" => "s=&fi=2&m=3&p=3",
"s=2&m=" => "s=2&fi=2&m=&p=3",
"s=2&m:=" => "s=2&fi=2&p=3&m=",
"z=9" => "s=1&fi=2&m=4&p=3&z=9",
"z:" => "s=1&fi=2&m=4&p=3&z",
"s:&m=3" => "fi=2&m=3&p=3&s",
"s&m=3" => "fi=2&m=3&p=3",
);
$test[1] = array(
"s" => "fi=&m=4&p=3",
"s&m" => "fi=&p=3",
"s=4" => "s=4&fi=&m=4&p=3",
"s=2&m" => "s=2&fi=&p=3",
"s=&m=3" => "s=&fi=&m=3&p=3",
"s=2&m=" => "s=2&fi=&m=&p=3",
"s=2&m:=" => "s=2&fi=&p=3&m=",
"z=9" => "s=&fi=&m=4&p=3&z=9",
"z:" => "s=&fi=&m=4&p=3&z",
);
foreach($cases as $x => $value) {
echo "<hr> CASE: $x <hr>\n";
foreach($test[$x] as $arg => $expected) {
$_GET = $cases[$x];
$res = myForm::fixGet($arg);
echo (($res === "?".$expected)?"OK":"NG ($res)")." [$arg]<br>\n";
}
}
?>
Parsing of GET/POST drops duplicate variables unless those variables have "[]" (PHP bugs #10502, #15498 and #16195). Adding "[]" makes a mess of your javascript code, so here is a small workaround to it.
This function basically scans your raw POST and GET input and tries to fix the same. This function must be called near the top of your script. Optimizations are welcome.
<?php
function php_fix_raw_query() {
$post = '';
// Try globals array
if (!$post && isset($_GLOBALS) && isset($_GLOBALS["HTTP_RAW_POST_DATA"]))
$post = $_GLOBALS["HTTP_RAW_POST_DATA"];
// Try globals variable
if (!$post && isset($HTTP_RAW_POST_DATA))
$post = $HTTP_RAW_POST_DATA;
// Try stream
if (!$post) {
if (!function_exists('file_get_contents')) {
$fp = fopen("php://input", "r");
if ($fp) {
$post = '';
while (!feof($fp))
$post = fread($fp, 1024);
fclose($fp);
}
} else {
$post = "" . file_get_contents("php://input");
}
}
$raw = !empty($_SERVER['QUERY_STRING']) ? sprintf('%s&%s', $_SERVER['QUERY_STRING'], $post) : $post;
$arr = array();
$pairs = explode('&', $raw);
foreach ($pairs as $i) {
if (!empty($i)) {
list($name, $value) = explode('=', $i, 2);
if (isset($arr[$name]) ) {
if (is_array($arr[$name]) ) {
$arr[$name][] = $value;
} else {
$arr[$name] = array($arr[$name], $value);
}
} else {
$arr[$name] = $value;
}
}
}
foreach ( $_POST as $key => $value ) {
if (is_array($arr[$key]) ) {
$_POST[$key] = $arr[$name];
$_REQUEST[$key] = $arr[$name];
}
}
foreach ( $_GET as $key => $value ) {
if (is_array($arr[$key]) ) {
$_GET[$key] = $arr[$name];
$_REQUEST[$key] = $arr[$name];
}
}
# optionally return result array
return $arr;
}
?>
the addget function below actually has more use when you dont use the recursive merge as such:
<?php
function AddGet($ArrayOrString){
if(is_array($ArrayOrString))
return http_build_query(array_merge($GLOBALS['_GET'], $ArrayOrString));
parse_str($ArrayOrString, $output);
return http_build_query(array_merge($GLOBALS['_GET'], $output));
}
?>
In this case, if the key is added again with a different value it will be replaced with the new value.
addget("change=true"); // ?change=true
addget("change=false"); // ?change=false
<?php
function AddGet($ArrayOrString){
if(is_array($ArrayOrString))
return http_build_query(array_merge_recursive($GLOBALS['_GET'], $ArrayOrString));
parse_str($ArrayOrString, $output);
return http_build_query(array_merge_recursive($GLOBALS['_GET'], $output));
}
?>
<a href="index.php?<?php echo AddGet(array("change"=>true,"jump"=>"42m"));?>">URL</a>
<a href="index.php?<?php echo AddGet("change=true&jump=42m");?>">URL</a>
Assuming the user entered http://example.com/?name=Hannes
The above example will output something similar to:
<a href="index.php?name=Hannes&change=1&jump=42m">URL</a>
<a href="index.php?name=Hannes&change=true&jump=42m">URL</a>
This code is really useful for reproducing the values in the $_GET variable, and attaching that to a $_SERVER['PHP_SELF'] value when building the action value of a form tag, so that you don't lose any other values that could have been passed:
foreach ($_GET as $key => $value) {
if ($key != "C") { // ignore this particular $_GET value
$querystring .= $key."=".$value;
}
}
Use this code if you want to retrieve your queries no matter what method is used. Hope it helps.
<?php
// By: RJ Regalado
// http://rjfiles.uni.cc/~php_examples/?id=1
$name = trim ((!empty($_POST['name'])) ? $_POST['name'] : $_GET['name'] );
if ( strlen ($name) < 1)
{
echo "Please enter your name";
} else {
printf ("Hello <b>%s</b><br>", $name);
printf ("Bonjour <b>%s</b><br>", $name);
printf ("Hallo <b>%s</b><br>", $name);
printf ("Ciao <b>%s</b><br>", $name);
printf ("Hola <b>%s</b><br>", $name);
}
?><hr>
<form method="POST">
Name: <input type="text" name="name">
<input type="submit" value="POST">
</form><hr>
<form method="GET">
Name: <input type="text" name="name">
<input type="submit" value="GET">
</form>
Note that named anchors are not part of the query string and are never submitted by the browser to the server.
Eg.
http://www.xyz-abc.kz/index.php?title=apocalypse.php#doom
echo $_GET['title'];
// returns "apocalypse.php" and NOT "apocalypse.php#doom"
you would be better off treating the named anchor as another query string variable like so:
http://www.xyz-abc.kz/index.php?title=apocalypse.php&na=doom
...and then retrieve it using something like this:
$url = $_GET['title']."#".$_GET['na'];
Hope this helps someone...
Note:
If nothing is set in the address bar, the value of $_GET['n'] will be NULL, not ""(empty string) or false.
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