PHP Chinese URL encoding and decoding (urlencode() rawurlencode()

PHP Chinese URL encoding and decoding (urlencode() rawurlencode()_PHP tutorial

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Release： 2016-07-21 15:36:44

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The following is a detailed explanation: ///\
string urlencode ( string str)
Returns a string. All non-alphanumeric characters in this string except -_. will be replaced with percent signs ( %) followed by two hexadecimal digits, and spaces are encoded as plus signs (+). This encoding is the same as the encoding of WWW form POST data, and the same encoding as the application/x-www-form-urlencoded media type. For historical reasons, this encoding differs from the RFC1738 encoding (see rawurlencode()) in encoding spaces as plus signs (+). This function facilitates encoding a string and using it in the request part of the URL, and it also facilitates passing variables to the next page: Example 1. urlencode() Example

Copy code The code is as follows:

echo '' ;
?>

Note: Be careful with variables that match HTML entities. Characters like &, © and £ will be parsed by the browser and the actual entity will be used instead of the expected variable name. This is obvious confusion, and the W3C has been warning people about it for several years. Reference address: http://www.w3.org/TR/html4/appendix/notes.html#h-B.2.2 PHP supports changing the parameter separator to the semicolon recommended by W3C through the arg_separator .ini directive. Unfortunately most user agents do not send form data in semicolon delimited format. A simpler solution is to use & instead of & as the delimiter. You don't need to modify PHP's arg_separator for this. Leave it still & and just use htmlentities(urlencode($data)) to encode your URL.
Example 2. urlencode() and htmlentities() Example

Copy code The code is as follows:

echo '';
?>

string urlencode (string str)
Returns a string in which all non-alphanumeric characters except -_. will be replaced with a percent sign (%) followed by two hexadecimal digits. This encoding, described in RFC 1738, is intended to protect literal characters from being interpreted as special URL delimiters, and to protect the URL format from being garbled by character conversions used by the transport medium (like some mail systems). For example, if you want to include the password in the FTP URL:
Example 1. rawurlencode() Example 1

Copy the code The code is as follows:

echo '';
?>

Or, if you want to pass information through the PATH_INFO component of the URL:
Example 2. rawurlencode( ) Example 2

Copy code The code is as follows:

echo '';
?>

When decoding, you can use the corresponding urldecode() and rawurldecode(). Correspondingly, rawurldecode() will not decode the plus sign ('+') into a space, but urldecode() can. Here's a detailed example:
string urldecode ( string str)
Decode any %## in the given encoded string. Returns the decoded string. Example 1. urldecode() example

Copy code The code is as follows:

 
$a = explode ('&', $QUERY_STRING); 
$i = 0; 
while ($i < count($a)) { 
$b = split('=', $a[$i ]); 
echo 'Value for parameter ', htmlspecialchars(urldecode($b[0])), 
' is ', htmlspecialchars(urldecode($b[1])), "
$i++; 
} 
?> 

string rawurldecode ( string str)
Returns a string, the percent sign ( %) followed by two hexadecimal digits will be replaced with literal characters.
Example 1. rawurldecode() Example

Copy code The code is as follows:

 
echo rawurldecode('foo%20bar%40baz'); // foo bar@baz 
?> 

However, one thing to note is that the string decoded by urldecode() and rawurldecode() is encoded in UTF-8 format. If the URL contains Chinese and the page setting is not UTF-8, The decoded string must be converted before it can be displayed normally!
There is another problem, that is, the obtained URL is not in the format of %%nn n={0..F}, but in the format of %unnnn n={0..F}. In this case, use urldecode() and rawurldecode() cannot be decoded correctly, and the following function must be used to decode correctly:

Copy code The code is as follows:

 
function utf8RawUrlDecode ($source) 
{ 
$decodedStr = ""; 
$pos = 0; 
$len = strlen ($source); 
while ($pos < $len) { 
$charAt = substr ($source, $pos, 1); 
if ($charAt == '%') { 
$pos++; 
$charAt = substr ($ source, $pos, 1); 
if ($charAt == 'u') { 
// we got a unicode character 
$pos++; 
$unicodeHexVal = substr ($source, $ pos, 4); 
$unicode = hexdec ($unicodeHexVal); 
$entity = "". $unicode . ';'; 
$decodedStr .= utf8_encode ($entity); 
$pos += 4; 
} 
else { 
// we have an escaped ascii character 
$hexVal = substr ($source, $pos, 2); 
$decodedStr . = chr (hexdec ($hexVal)); 
$pos += 2; 
} 
} else { 
$decodedStr .= $charAt; 
$pos++; 
} 
} 
return $decodedStr; 
} 