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

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用户贡献的备注 6 notes

down

davis dot peixoto at gmail dot com ¶

14 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 ¶

15 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

materialsmoke at gmail dot com ¶

1 year 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

daniel+php at danielnorton dot com ¶

15 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

omid at omidsakhi dot com ¶

14 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

ahrensberg at gmail dot com ¶

17 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.