[原创]PHP中GBK和UTF8编码处理

 

一、编码范围

1. GBK (GB2312/GB18030)
/x00-/xff  GBK双字节编码范围
/x20-/x7f  ASCII
/xa1-/xff  中文
/x80-/xff  中文

2. UTF-8 (Unicode)
/u4e00-/u9fa5 (中文)
/x3130-/x318F (韩文
/xAC00-/xD7A3 (韩文)
/u0800-/u4e00 (日文)
ps: 韩文是大于[/u9fa5]的字符

正则例子:
preg_replace("/([/x80-/xff])/","",$str);
preg_replace("/([u4e00-u9fa5])/","",$str);

 

二、代码例子

//判断内容里有没有中文-GBK (PHP)
function check_is_chinese ( $ s ) {
     return preg_match ( '/[/x80-/xff]./' , $ s ) ;
}

//获取字符串长度-GBK (PHP)
function gb_strlen ( $ str ) {
     $ count = 0 ;
     for ( $ i =0 ; $ i < strlen ( $ str ) ; $ i + + ) {
         $ s = substr ( $ str , $ i , 1 ) ;
         if ( preg_match ( "/[/x80-/xff]/" , $ s ) ) + + $ i ;
         + + $ count ;
     }
     return $ count ;
}

//截取字符串字串-GBK (PHP)
function gb_substr ( $ str , $ len ) {
     $ count = 0 ;
     for ( $ i =0 ; $ i < strlen ( $ str ) ; $ i + + ) {
         if ( $ count = = $ len ) break ;
         if ( preg_match ( "/[/x80-/xff]/" , substr ( $ str , $ i , 1 ) ) ) + + $ i ;
         + + $ count ;         
     }
     return substr ( $ str , 0 , $ i ) ;
}

//统计字符串长度-UTF8 (PHP)
function utf8_strlen ( $ str ) {
     $ count = 0 ;
     for ( $ i = 0 ; $ i < strlen ( $ str ) ; $ i + + ) {
         $ value = ord ( $ str [ $ i ] ) ;
         if ( $ value > 127 ) {
             $ count + + ;
             if ( $ value > = 192 & & $ value < = 223 ) $ i + + ;
             elseif ( $ value > = 224 & & $ value < = 239 ) $ i = $ i + 2 ;
             elseif ( $ value > = 240 & & $ value < = 247 ) $ i = $ i + 3 ;
             else die ( 'Not a UTF-8 compatible string' ) ;
         }
         $ count + + ;
     }
     return $ count ;
}


//截取字符串-UTF8(PHP)
function utf8_substr ( $ str , $ position , $ length ) {
     $ start_position = strlen ( $ str ) ;
     $ start_byte = 0 ;
     $ end_position = strlen ( $ str ) ;
     $ count = 0 ;
     for ( $ i = 0 ; $ i < strlen ( $ str ) ; $ i + + ) {
         if ( $ count > = $ position & & $ start_position > $ i ) {
             $ start_position = $ i ;
             $ start_byte = $ count ;
         }
         if ( ( $ count - $ start_byte ) > = $ length ) {
             $ end_position = $ i ;
             break ;
         }     
         $ value = ord ( $ str [ $ i ] ) ;
         if ( $ value > 127 ) {
             $ count + + ;
             if ( $ value > = 192 & & $ value < = 223 ) $ i + + ;
             elseif ( $ value > = 224 & & $ value < = 239 ) $ i = $ i + 2 ;
             elseif ( $ value > = 240 & & $ value < = 247 ) $ i = $ i + 3 ;
             else die ( 'Not a UTF-8 compatible string' ) ;
         }
         $ count + + ;

     }
     return ( substr ( $ str , $ start_position , $ end_position - $ start_position ) ) ;
}


//字符串长度统计-UTF8 [中文3个字节，俄文、韩文占2个字节，字母占1个字节] (Ruby)
def utf8_string_length (str )
    temp = CGI : :unescape (str )
    i = 0 ;
    j = 0 ;
    temp .length .times { |t |
         if temp [t ] < 127
            i + = 1
         elseif temp [t ] > = 127 and temp [t ] < 224
            j + = 1
             if 0 = = (j % 2 )
                i + = 2
                j = 0
             end
         else
            j + = 1
             if 0 = = (j % 3 )
                i + = 2
                j = 0
             end
         end
     }
     return i
}

//判断是否是有韩文-UTF-8 (JavaScript)
function checkKoreaChar (str ) {
     for (i =0 ; i <str .length ; i + + ) {
         if ( ( (str .charCodeAt (i ) > 0x3130 & & str .charCodeAt (i ) < 0x318F ) | | (str .charCodeAt (i ) > = 0xAC00 & & str .charCodeAt (i ) < = 0xD7A3 ) ) ) {
             return true ;
         }
     }
     return false ;
}

//判断是否有中文字符-GBK (JavaScript)
function check_chinese_char(s){
    return (s.length != s.replace(/[^/x00-/xff]/g,"**").length);
}

 

三、参考文档

http://www.unicode.org/
http://examples.oreilly.com/cjkvinfo/doc/cjk.inf
http://www.ansell-uebersetzungen.com/gbuni.html
http://www.haiyan.com/steelk/navigator/ref/gbk/gbindex.htm
http://baike.baidu.com/view/40801.htm
http://www.chedong.com/tech/hello_unicode.html