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Parsing the escape function in php_PHP tutorial

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Release： 2016-07-21 15:02:22

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Use js to escape encode the Chinese characters in the URL.
The effect after clicking the link is:
Quote: http://127.0.0.1/shop/product_list.php?p_sort=PHP%u5F00%u53D1%u8D44%u6E90%u7F51
To generate such an effect, it is obvious to use PHP's urldecode() or base64_decode() cannot be decoded.
Solution, use PHP to write an inverse solution function:

Copy the code The code is as follows:

function js_unescape($str){
{ str, $i+2, 4)); 0xc0|($val>>6)).chr(0x80|($val&0x3f)); >6)&0x3f)).chr(0x80|($val&0x3f)); == '%') 🎜>{
else $ret .= $str[$i ]; But if you use UTF-8 encoding, this step is not necessary.

The code is as follows: print iconv('utf-8', 'gb2312', js_unescape($_REQUEST['p_sort']));

At this point we have successfully decoded js The escape is encoded.
As follows:
In addition, I found a function that uses PHP to implement escape encoding of js:

Copy the code

The code is as follows:

function phpescape($str)
{         
$sublen=strlen($str);
      $retrunString="";         
for ($i=0;$i<$sublen;$i++)         
{                  
if(ord($str[$i])>=127)                  
{                           
$tmpString=bin2hex(iconv("gb2312","ucs-2",substr($str,$i,2)));                           
//$tmpString=substr($tmpString,2,2).substr($tmpString,0,2);window下可能要打开此项                           
$retrunString.="%u".$tmpString;                           
$i++;                  
} else 
{                           
$retrunString.="%".dechex(ord($str[$i]));                  
}         
}         
return $retrunString;
}

在json中不支持中文，用它传送中文数据就会出现数据丢失或者乱码，必须在传送前对要发送的字符串进行编码，由于传送过去需要用js进行数据解析，考虑到js中有unescape函数，故若在php中有个escape函数，对数据进行编码，在客户端用unescape进行解码，这样就会方便很多。
先在网上搜索一把，很多用php实现的escape函数，大同小异，比如下面一个：

复制代码代码如下:

function phpEscape($str) {
preg_match_all("/[x80-xff].|[x01-x7f]+/",$str,$r);
$ar = $r[0];
foreach($ar as $k=>$v) {
    if(ord($v[0]) < 128)
      $ar[$k] = rawurlencode($v);
    else
      $ar[$k] = "%u".bin2hex(iconv("GB2312","UCS-2",$v));
}
return join("",$ar);
}

这个函数可以很好的工作，但是，也许有新手不理解这个函数的原理(比如我)，用起来总是不放心，现在我就来解释一下这个函数的原理。而且我认为，拿别人的代码来复用，好比站在了巨人的肩膀上，但是若不理解别人的代码，迟早要掉到地面上。
第一句：preg_match_all("/[x80-xff].|[x01-x7f]+/",$str,$r);这个是用正则表达式匹配字符串中所有的字符，[x80-xff]. 匹配的是汉字，x表示匹配字符的16进制编码，[ ] 是类选择符，“.” 表示任意一个字符，这样[x80-xff].匹配的是两个字符，其中第一个就是16进制从80到ff的字符，而这恰好就是汉字编码的第一个字符。这样就能完整的匹配一个汉字。关于unicode中汉字的编码，大家可以到网上搜索一下。同理，[x01-x7f]+英文字符串，因为最早的英文是 ASCII编码，编码值小于128，也就是16进制的从01到7f，"+"表示一个或者多个字符，这样[x01-x7f]+就能匹配连续多个英文字符串。

复制代码代码如下:

$ar = $r[0]; //$r[0] stores the matched array
foreach($ar as $k=>$v) {
 if (ord($v[0]) < 128) //If the character encoding value is less than 128, it means it is an English character 
 $ar[$k] = rawurlencode($v); //Use rawurlencode to encode directly
 else
 $ar[$k] = "%u".bin2hex(iconv("GB2312","UCS-2",$v)); // Otherwise, use the iconv function to convert Chinese characters into ucs-2 Encoding, that is, unicode encoding 
}

can be decoded with unescape in javascript
u0391-uFFE5 and u4e00-u9fa5 to match Chinese
but it seems that the former contains Chinese characters The latter A-￥ and so on below may be pure Chinese characters.
The decoding function is:

Copy code The code is as follows:

function unescape($str) {
 $str = rawurldecode($str);
 preg_match_all("/%u.{4}|&#x.{4};|&#d+;|.+/U",$str,$r); 
 $ar = $r[0];
 foreach($ar as $k=>$v) {
 if(substr($v,0,2) == "%u") 
                     $ar[$k] = iconv("UCS-2","GBK",pack("H4",substr($v,-4))); ,3) == "")
                                                                                       );
                  elseif(substr($v,0,2) == "") { ",substr($v,2,-1)));
 }
 }
 return join("",$ar);
}