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urlencode

(PHP 4, PHP 5, PHP 7, PHP 8)

urlencode — 编码 URL 字符串

说明

urlencode(string $string): string

此函数便于将字符串编码并将其用于 URL 的请求部分，同时它还便于将变量传递给下一页。

参数

string: 要编码的字符串。

返回值

返回字符串，此字符串中除了 -_. 之外的所有非字母数字字符都将被替换成百分号（%）后跟两位十六进制数，空格则编码为加号（+）。此编码与 WWW 表单 POST 数据的编码方式是一样的，同时与 application/x-www-form-urlencoded 的媒体类型编码方式一样。由于历史原因，此编码在将空格编码为加号（+）方面与 » RFC3986 编码（参见 rawurlencode()）不同。

示例

示例 #1 urlencode() 例子

<?php
$userinput = 'Data123!@-_ +';
echo "UserInput: $userinput\n";
echo '<a href="mycgi?foo=', urlencode($userinput), '">';
?>

以上示例会输出：

 
UserInput: Data123!@-_ +
<a href="mycgi?foo=Data123%21%40-_+%2B">

示例 #2 urlencode() 与 htmlentities() 例子

<?php
$foo = 'Data123!@-_ +';
$bar = "Not the same content as $foo";
echo "foo: $foo\n";
echo "bar: $bar\n";
$query_string = 'foo=' . urlencode($foo) . '&bar=' . urlencode($bar);
echo '<a href="mycgi?' . htmlentities($query_string) . '">';
?>

以上示例会输出：

 
foo: Data123!@-_ +
bar: Not the same content as Data123!@-_ +
<a href="mycgi?foo=Data123%21%40-_+%2B&amp;bar=Not+the+same+content+as+Data123%21%40-_+%2B">

注释

注意:
注意：小心与 HTML 实体相匹配的变量。像 &amp、&copy 和 &pound 都将被浏览器解析，并使用实际实体替代所期待的变量名。这是明显的混乱，W3C 已经告诫人们好几年了。参考地址：» http://www.w3.org/TR/html4/appendix/notes.html#h-B.2.2。

PHP 通过 arg_separator.ini 指令，支持将参数分割符变成 W3C 所建议的分号。不幸的是大多数用户代理并不发送分号分隔符格式的表单数据。较为简单的解决办法是使用 & 代替 & 作为分隔符。你不需要为此修改 PHP 的 arg_separator。让它仍为 &，而仅使用 htmlentities() 或 htmlspecialchars() 对你的 URL 进行编码。

参见

urldecode() - 解码已编码的 URL 字符串
htmlentities() - 将字符转换为 HTML 转义字符
rawurlencode() - 按照 RFC 3986 对 URL 进行编码
rawurldecode() - 对已编码的 URL 字符串进行解码
» RFC 3986

＋add a note

User Contributed Notes 26 notes

down

davis dot peixoto at gmail dot com ¶

13 years ago

urlencode function and rawurlencode are mostly based on RFC 1738.

However, since 2005 the current RFC in use for URIs standard is RFC 3986.

Here is a function to encode URLs according to RFC 3986.

<?php
function myUrlEncode($string) {
    $entities = array('%21', '%2A', '%27', '%28', '%29', '%3B', '%3A', '%40', '%26', '%3D', '%2B', '%24', '%2C', '%2F', '%3F', '%25', '%23', '%5B', '%5D');
    $replacements = array('!', '*', "'", "(", ")", ";", ":", "@", "&", "=", "+", "$", ",", "/", "?", "%", "#", "[", "]");
    return str_replace($entities, $replacements, urlencode($string));
}
?>

down

temu92 at gmail dot com ¶

14 years ago

I needed encoding and decoding for UTF8 urls, I came up with these very simple fuctions. Hope this helps!

<?php
    function url_encode($string){
        return urlencode(utf8_encode($string));
    }
    
    function url_decode($string){
        return utf8_decode(urldecode($string));
    }
?>

down

omid at omidsakhi dot com ¶

13 years ago

I needed a function in PHP to do the same job as the complete escape function in Javascript. It took me some time not to find it. But findaly I decided to write my own code. So just to save time:



<?php

function fullescape($in)

{

  $out = '';

  for ($i=0;$i<strlen($in);$i++)

  {

    $hex = dechex(ord($in[$i]));

    if ($hex=='') 

       $out = $out.urlencode($in[$i]);

    else 

       $out = $out .'%'.((strlen($hex)==1) ? ('0'.strtoupper($hex)):(strtoupper($hex)));

  }

  $out = str_replace('+','%20',$out);

  $out = str_replace('_','%5F',$out);

  $out = str_replace('.','%2E',$out);

  $out = str_replace('-','%2D',$out);

  return $out;

 }

?>



It can be fully decoded using the unscape function in Javascript.

down

daniel+php at danielnorton dot com ¶

14 years ago

Don't use urlencode() or urldecode() if the text includes an email address, as it destroys the "+" character, a perfectly valid email address character.

Unless you're certain that you won't be encoding email addresses AND you need the readability provided by the non-standard "+" usage, instead always use use rawurlencode() or rawurldecode().

down

izhankhalib at gmail dot com ¶

10 years ago

Below is our jsonform source code in  mongo db which consists a lot of double quotes. we are able to pass this source code to the ajax form submit function by using php urlencode :

<script type="text/javascript">
$(function() {
      // Generate a form using jquery.dfrom
        $("#myform").dform({
                       
        "html":[
            {
                "type":"p",
                "html":"Patient Record"
            },
            {
                "name":"patient.name.first",
                "id":"txt-patient.name.first",
                "caption":"first name",
                "type":"text",
            },
            {
                
                "name":"patient.name.last",
                "id":"txt-patient.name.last",
                "caption":"last name",
                "type":"text",
            },
            {
               "type" : "submit",
              }
            
        ]
    });
    });
</script>
<form id="myform">

<?php
//get the json source code from the mongodb
$jsonform= urlencode($this->data['Post']['jsonform']);

?>
//AJAX SUBMIT FORM
<script type="text/javascript">
$('#myform').submit(function(){
  
                
    //    passing the variable fro PHP to javascript    
        var thejsonform="<?php echo $jsonform ?>";

  //var fname = $('input#fname').val();
  var dataString = "jsonform=" + thejsonform ; 

    $.ajax({
          type: "POST",
        //  url: "test1.php",
          data: dataString,
          success: function() {
           
          }
         }); 
  

return false;
});

down

materialsmoke at gmail dot com ¶

2 months ago

this function will encode the URL while preserving the functionality of URL so you can copy and paste it in the browser
```
function urlEncode($url) {
    $parsedUrl = parse_url($url);
    
    $encodedScheme = urlencode($parsedUrl['scheme']);
    $encodedHost = urlencode($parsedUrl['host']);
    
    $encodedPath = implode('/', array_map('urlencode', explode('/', $parsedUrl['path'])));
    if (isset($parsedUrl['query'])) {
        $encodedQuery = '?' . urlencode($parsedUrl['query']);
    } else {
        $encodedQuery = '';
    }
    
    return "{$encodedScheme}://{$encodedHost}{$encodedPath}{$encodedQuery}";
}
```

down

ahrensberg at gmail dot com ¶

16 years ago

Like "Benjamin dot Bruno at web dot de" earlier has writen, you can have problems with encode strings with special characters to flash. Benjamin write that:

<?php
   function flash_encode ($input)
   {
      return rawurlencode(utf8_encode($input));
   }
?>

... could do the problem. Unfortunately flash still have problems with read some quotations, but with this one:

<?php
   function flash_encode($string)
   {
      $string = rawurlencode(utf8_encode($string));

      $string = str_replace("%C2%96", "-", $string);
      $string = str_replace("%C2%91", "%27", $string);
      $string = str_replace("%C2%92", "%27", $string);
      $string = str_replace("%C2%82", "%27", $string);
      $string = str_replace("%C2%93", "%22", $string);
      $string = str_replace("%C2%94", "%22", $string);
      $string = str_replace("%C2%84", "%22", $string);
      $string = str_replace("%C2%8B", "%C2%AB", $string);
      $string = str_replace("%C2%9B", "%C2%BB", $string);

      return $string;
   }
?>

... should solve this problem.

down

youhanasobhy15 at gmail dot com ¶

5 years ago

Keep in mind that, if you prepare URL for a connection and used the urlencode on some parameters and didn't use it on the rest of parameters, it will not be decoded automatically at the destination position if the not encoded parameters have special characters that urlencode encodes it.

example :

$xml = simplexml_load_file("http://www.testing.com?me=test&first=".urlencode('dummy string')."&second=here is the string");

here is the second parameter has spaces which urlencode converts it to (+).

after using this URL, the server will discover that the second parameter has not been encoded , then the server will not decode it automatically.

this took more than 2 hours to be discovered and hope to save your time.

down

david winiecki gmail ¶

8 years ago

Since PHP 5.3.0, urlencode and rawurlencode also differ in that rawurlencode does not encode ~ (tilde), while urlencode does.

down

-2

kL ¶

17 years ago

Apache's mod_rewrite and mod_proxy are unable to handle urlencoded URLs properly - http://issues.apache.org/bugzilla/show_bug.cgi?id=34602

If you need to use any of these modules and handle paths that contain %2F or %3A (and few other encoded special url characters), you'll have use a different encoding scheme.

My solution is to replace "%" with "'".
<?php
function urlencode($u)
{
    return str_replace(array("'",'%'),array('%27',"'"),urlencode($u));
}

function urldecode($u)
{
    return urldecode(strtr($u,"'",'%'));
}
?>

down

-2

root at jusme dot org ¶

15 years ago

I'm running PHP version 5.0.5 and urlencode() doesn't seem to encode the "#" character, although the function's description says it encodes "all non-alphanumeric" characters. This was a particular problem for me when trying to open local files with a "#" in the filename as Firefox will interpret this as an anchor target (for better or worse). It seems a manual str_replace is required unless this was fixed in a future PHP version.

Example:

$str = str_replace("#", "%23", $str);

down

-3

frx dot apps at gmail dot com ¶

13 years ago

I wrote this simple function that creates a GET query (for URLS) from an array:

<?php
function encode_array($args)
{
  if(!is_array($args)) return false;
  $c = 0;
  $out = '';
  foreach($args as $name => $value)
  {
    if($c++ != 0) $out .= '&';
    $out .= urlencode("$name").'=';
    if(is_array($value))
    {
      $out .= urlencode(serialize($value));
    }else{
      $out .= urlencode("$value");
    }
  }
  return $out . "\n";
}
?>

If there are arrays within the $args array, they will be serialized before being urlencoded.

Some examples:
<?php
echo encode_array(array('foo' => 'bar'));                    // foo=bar
echo encode_array(array('foo&bar' => 'some=weird/value'));   // foo%26bar=some%3Dweird%2Fvalue
echo encode_array(array('foo' => 1, 'bar' =>  'two'));       // foo=1&bar=two
echo encode_array(array('args' => array('key' => 'value'))); // args=a%3A1%3A%7Bs%3A3%3A%22key%22%3Bs%3A5%3A%22value%22%3B%7D
?>

down

-2

lekiagospel@gmail dot com ¶

2 years ago

urlencode is useful when using certain URL shortener services.

The returned URL from the shortener may be truncated if not encoded. Ensure the URL is encoded before passing it to a shortener.

Example 

$url = "https://www.notarealurl.com?id=50&name=namestring";
$encodedurl = urlencode($url);
$shorturl = UrlShortener::shortenUrl( $encodedurl);

down

-3

R Mortimer ¶

18 years ago

Do not let the browser auto encode an invalid URL. Not all browsers perform the same encodeing. Keep it cross browser do it server side.

down

-4

neugey at cox dot net ¶

19 years ago

Be careful when encoding strings that came from simplexml in PHP 5.  If you try to urlencode a simplexml object, the script tanks.

I got around the problem by using a cast.

$newValue = urlencode( (string) $oldValue );

down

-4

in reply to "kL" ¶

16 years ago

kL's example is very bugged since it loops itself and the encode function is two-way.

Why do you replace all %27 through '  in the same string in that you replace all ' through %27?

Lets say I have a string: Hello %27World%27. It's a nice day.
I get: Hello Hello 'World'. It%27s a nice day.

With other words that solution is pretty useless.

Solution:
Just replace ' through %27 when encoding
Just replace %27 through ' when decoding. Or just use url_decode.

down

-4

no_gravity ¶

3 years ago

I think the description does not exactly match what the function does:

    Returns a string in which all non-alphanumeric characters
    except -_. have been replaced with a percent (%) sign followed
    by two hex digits and spaces encoded as plus (+) signs.

urlencode('ö') gives me '%C3%B6'. So more then just a percent sign followed by two hex digits.

down

-5

admin at server dot net ¶

4 years ago

urlencode corresponds to the definition for application/x-www-form-urlencoded in RFC 1866 (https://tools.ietf.org/html/rfc1866#section-8.2.1), and not for url encoded parts in URI. Use only rawurlencode for encode raw URI parts (e.g. query/search part)!

down

-8

monty3 at hotmail dot com ¶

19 years ago

If you want to pass a url with parameters as a value IN a url AND through a javascript function, such as...

   <a href="javascript:openWin('page.php?url=index.php?id=4&pg=2');">

...pass the url value through the PHP urlencode() function twice, like this...

<?php

   $url = "index.php?id=4&pg=2";
   $url = urlencode(urlencode($url));

   echo "<a href=\"javascript:openWin('page.php?url=$url');\">";
?>

On the page being opened by the javascript function (page.php), you only need to urldecode() once, because when javascript 'touches' the url that passes through it, it decodes the url once itself. So, just decode it once more in your PHP script to fully undo the double-encoding...

<?php

   $url = urldecode($_GET['url']);
?>

If you don't do this, you'll find that the result url value in the target script is missing all the var=values following the ? question mark...

   index.php?id=4

down

-10

Mark Seecof ¶

15 years ago

When using XMLHttpRequest or another AJAX technique to submit data to a PHP script using GET (or POST with content-type header set to 'x-www-form-urlencoded') you must urlencode your data before you upload it.  (In fact, if you don't urlencode POST data MS Internet Explorer may pop a "syntax error" dialog when you call XMLHttpRequest.send().)  But, you can't call PHP's urlencode() function in Javascript!  In fact, NO native Javascript function will urlencode data correctly for form submission.  So here is a function to do the job fairly efficiently:

<?php /******

<script type="text/javascript" language="javascript1.6">
 // PHP-compatible urlencode() for Javascript
 function urlencode(s) {
  s = encodeURIComponent(s);
  return s.replace(/~/g,'%7E').replace(/%20/g,'+');
 }

 // sample usage:  suppose form has text input fields for
 // country, postcode, and city with id='country' and so-on.
 // We'll use GET to send values of country and postcode
 // to "city_lookup.php" asynchronously, then update city
 // field in form with the reply (from database lookup)

 function lookup_city() {
  var elm_country = document.getElementById('country');
  var elm_zip = document.getElementById('postcode');
  var elm_city = document.getElementById('city');
  var qry = '?country=' + urlencode(elm_country.value) +
                '&postcode=' + urlencode(elm_zip.value);
  var xhr;
  try {
   xhr = new XMLHttpRequest(); // recent browsers
  } catch (e) {
   alert('No XMLHttpRequest!');
   return;
  }
  xhr.open('GET',('city_lookup.php'+qry),true);
  xhr.onreadystatechange = function(){
    if ((xhr.readyState != 4) || (xhr.status != 200)) return;
    elm_city.value = xhr.responseText;
  }
  xhr.send(null);
 }
</script>

******/ ?>

down

-8

torecs at sfe dot uio dot no ¶

17 years ago

This very simple function makes an valid parameters part of an URL, to me it looks like several of the other versions here are decoding wrongly as they do not convert & seperating the variables into &amp;. 

  $vars=array('name' => 'tore','action' => 'sell&buy');
  echo MakeRequestUrl($vars);
  
  /* Makes an valid html request url by parsing the params array
   * @param $params The parameters to be converted into URL with key as name.
   */
  function MakeRequestUrl($params)
  {
      $querystring=null;
    foreach ($params as $name => $value)
    {
      $querystring=$name.'='.urlencode($value).'&'.$querystring;
    }
      // Cut the last '&'
      $querystring=substr($querystring,0,strlen($querystring)-1);
      return htmlentities($querystring);
  }

  Will output: action=sell%26buy&amp;name=tore

down

-11

edwardzyang at thewritingpot dot com ¶

18 years ago

I was testing my input sanitation with some strange character entities. Ones like ? and ? were passed correctly and were in their raw form when I passed them through without any filtering.

However, some weird things happen when dealing with characters like (these are HTML entities): &#8252; &#9616; &#9488;and &#920; have weird things going on.

If you try to pass one in Internet Explorer, IE will *disable* the submit button. Firefox, however, does something weirder: it will convert it to it's HTML entity. It will display properly, but only when you don't convert entities.

The point? Be careful with decorative characters.

PS: If you try copy/pasting one of these characters to a TXT file, it will translate to a ?.

down

-9

nehuensd at gmail dot com ¶

9 years ago

if you have a url like this: test-blablabla-4>3-y-3<6 or with any excluded US-ASCII Characters (see chapter 2.4.3 on http://www.ietf.org/rfc/rfc2396.txt) you can use urlencode two times for fix the 403 error.

Example:
.htaccess
Options +FollowSymLinks
RewriteEngine on 
RewriteRule ^test-(.*)$ index.php?token=$1

index.php
<?php
    var_dump($_GET);
    
    $foo = 'test-bla-bla-4>2-y-3<6';
    $foo_encoded = urlencode(urlencode($foo));
?>
<a href="<?=$foo_encoded;?>"><?=$foo_encoded;?></a>

look on index.php
array (size=0)
  empty
test-bla-bla-4%253E2-y-3%253C6

look on test-bla-bla-4%253E2-y-3%253C6
array (size=1)
  'token' => string 'bla-bla-4>2-y-3<6' (length=17)
test-bla-bla-4%253E2-y-3%253C6

the problem is that the characters are decoded 2 times, 1 single, the first time mod_rewrite, the second is to create the php $ _GET array.

also, you can use this technique to the same as the complex functions of other notes.

down

-16

homebot at yandex dot ru ¶

10 years ago

Simple static class for array URL encoding

[code]

<?php

/**
* 
*  URL Encoding class
*  Use : urlencode_array::go() as function
* 
*/
class urlencode_array
{

  /** Main encoding worker
  * @param string $perfix
  * @param array $array
  * @param string $ret byref Push record to return array
  * @param mixed $fe Is first call to function?
  */
  private static function encode_part($perfix, $array, &$ret, $fe = false)
  {
    foreach ( $array as $k => $v )
    {
      switch ( gettype($v))
      {
        case 'float'   : 
        case 'integer' :
        case 'string'  : $ret [ $fe ? $k : $perfix.'['.$k.']' ] = $v; break;
        case 'boolean' : $ret [ $fe ? $k : $perfix.'['.$k.']' ] = ( $v ? '1' : '0' ); break;
        case 'null'    : $ret [ $fe ? $k : $perfix.'['.$k.']' ] = 'NULL'; break;
        case 'object'  : $v = (array) $v;
        case 'array'   : self::encode_part( $fe?$perfix.$k:$perfix.'['.$k.']' , $v, $ret, false); break;
      }
    }
  }

  /** UrlEncode Array
  * @param mixed $array Array or stdClass to encode
  * @returns string Strings ready for send as 'application/x-www-form-urlencoded'
  */
  public static function go($array)
  {
    $buff = array();
    if ( gettype($array) == 'object') $array = (array) $array;
    self::encode_part('', $array, $buff, true);
    $retn = '';
    foreach ( $buff as $k => $v )
      $retn .= urlencode($k) . '=' . urlencode($v) . '&';
    return $retn;
  }
}

#-------------------------------- TEST AREA ------------------------------------

$buffer = array(
  'master'  =>'master.zenith.lv',
  'join'    =>array('slave'=>'slave1.zenith.lv','slave2'=>array('node1.slave2.zenith.lv','slave2.zenith.lv')),
  'config'  => new stdClass()
);
$buffer['config']->MaxServerLoad  = 200;
$buffer['config']->MaxSlaveLoad   = 100;
$buffer['config']->DropUserNoWait = true;

$buffer = urlencode_array::go($buffer);
parse_str( $buffer , $data_decoded);

header('Content-Type: text/plain; charset=utf-8');
echo 'Encoded String :' . str_repeat('-', 80) . "\n";
echo $buffer;
echo str_repeat("\n", 3) . 'Decoded String byPhp :' . str_repeat('-', 80) . "\n";
print_r($data_decoded);

[/code]

down

-5

GeorgeOxymn ¶

2 years ago

Стань королем настоящего средневекового королевства! 
Захватывающая RPG игра и симулятор замка 
https://fas.st/tdhru

down

-11

bisqwit at iki dot fi ¶

18 years ago

Constructing hyperlinks safely HOW-TO:

<?php
$path_component = 'machine/generated/part';
$url_parameter1 = 'this is a string';
$url_parameter2 = 'special/weird "$characters"';

$url = 'http://example.com/lab/cgi/test/'. rawurlencode($path_component) . '?param1=' . urlencode($url_parameter1) . '&param2=' . urlencode($url_parameter2);

$link_label = "Click here & you'll be <happy>";

echo '<a href="', htmlspecialchars($url), '">', htmlspecialchars($link_label), '</a>';
?>

This example covers all the encodings you need to apply in order to create URLs safely without problems with any special characters. It is stunning how many people make mistakes with this.

Shortly:
- Use urlencode for all GET parameters (things that come after each "=").
- Use rawurlencode for parts that come before "?".
- Use htmlspecialchars for HTML tag parameters and HTML text content.

＋add a note