用php实现gb2312和unicode间的编码转换

gb2312 和 unicode 间的编码转换
下面的例子是将 gb2312 转换为 "全"这种形式
php4.3.1以后的iconv函数很好用的，只是需要自己写一个uft8到unicode的转换函数查表(gb2312.txt)也行<?$text = "电子书库";preg_match_all("/[\x80-\xff]?./",$text,$ar);foreach($ar[0] as $v)  echo "&#".utf8_unicode(iconv("GB2312","UTF-8",$v)).";";?><?// utf8 -> unicodefunction utf8_unicode($c) {  switch(strlen($c)) {    case 1:      return ord($c);    case 2:      $n = (ord($c[0]) & 0x3f) << 6;      $n += ord($c[1]) & 0x3f;      return $n;    case 3:      $n = (ord($c[0]) & 0x1f) << 12;      $n += (ord($c[1]) & 0x3f) << 6;      $n += ord($c[2]) & 0x3f;      return $n;    case 4:      $n = (ord($c[0]) & 0x0f) << 18;      $n += (ord($c[1]) & 0x3f) << 12;      $n += (ord($c[2]) & 0x3f) << 6;      $n += ord($c[3]) & 0x3f;      return $n;  }}?>
下面的例子是利用php将"&#20840;"这中编码转换为gb2312.<?php$str = "TTL&#20840;&#22825;&#20505;&#33258;&#21160;&#32858;&#28966;";$str = preg_replace("|&#([0-9]{1,5});|", "\".u2utf82gb(<A href="file://\\1).\">\\1).\</A>"", $str);$str = "\$str=\"$str\";";
eval($str);echo $str;
function u2utf82gb($c){    $str="";    if ($c < 0x80) {         $str.=$c;    } else if ($c < 0x800) {         $str.=chr(0xC0 | $c>>6);         $str.=chr(0x80 | $c & 0x3F);    } else if ($c < 0x10000) {         $str.=chr(0xE0 | $c>>12);         $str.=chr(0x80 | $c>>6 & 0x3F);         $str.=chr(0x80 | $c & 0x3F);    } else if ($c < 0x200000) {         $str.=chr(0xF0 | $c>>18);         $str.=chr(0x80 | $c>>12 & 0x3F);         $str.=chr(0x80 | $c>>6 & 0x3F);         $str.=chr(0x80 | $c & 0x3F);    }    return iconv('UTF-8', 'GB2312', $str);}?>
或者是
function unescape($str) {  $str = rawurldecode($str);  preg_match_all("/(?:%u.{4})|&#x.{4};|&#\d+;|.+/U",$str,$r);  $ar = $r[0];print_r($ar);  foreach($ar as $k=>$v) {    if(substr($v,0,2) == "%u")      $ar[$k] = iconv("UCS-2","GB2312",pack("H4",substr($v,-4)));    elseif(substr($v,0,3) == "&#x")      $ar[$k] = iconv("UCS-2","GB2312",pack("H4",substr($v,3,-1)));    elseif(substr($v,0,2) == "&#") {echo substr($v,2,-1)."<br>";      $ar[$k] = iconv("UCS-2","GB2312",pack("n",substr($v,2,-1)));    }  }  return join("",$ar);}
$str = "TTL&#20840;&#22825;&#20505;&#33258;&#21160;&#32858;&#28966;";echo unescape($str); //out TTL全天候自动聚焦
 
利用javascript来转换
<style>BODY { FONT-SIZE: 9pt; PADDING-RIGHT: 0px; PADDING-LEFT: 0px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px;}input { FONT-SIZE: 9pt; height: 13pt;}</style>
<script language="JavaScript1.2">/* This following code are designed and writen by Windy_sk <<A href="mailto:seasonx@163.net">seasonx@163.net</A>> You can use it freely, but u must held all the copyright items!*/
function Str2Unicode(str){ var arr = new Array(); for(var i=0;i<str.length;i++){  arr[i]="&#" + str.charCodeAt(i) + ";"; } return(arr.toString().replace(/,/g,""));}
function Unicode2oStr(str){ var re=/&#[\da-fA-F]{1,5};/ig; var arr=str.match(re); if(arr==null)return(""); for(var i=0;i<arr.length;i++){  arr[i]=String.fromCharCode(arr[i].replace(/[&#;]/g,"")); } return(arr.toString().replace(/,/g,""))}
function modi_str(){ if(document.all.text.method.checked){  if(document.all.text.decode.value!=""){   document.all.text.encode.value = Str2Unicode(document.all.text.decode.value);  }else{   document.all.text.decode.value = Unicode2oStr(document.all.text.encode.value);  } }else{  if(document.all.text.encode.value!=""){   document.all.text.decode.value = Unicode2oStr(document.all.text.encode.value);  }else{   document.all.text.encode.value = Str2Unicode(document.all.text.decode.value);  } }}</script><title>Unicode</title><form name=text>文本原型：<br>  <textarea name="decode" cols="100" rows="10"></textarea>  <br>转换代码：<br>  <textarea name="encode" cols="100" rows="10"></textarea>  <br>  <input type="checkbox" name="method" checked> 正向转换  <input type=button onclick="modi_str()" value=" 确 定 ">  <input type=reset value=" 清 空 ">  <input type=button onclick="document.all.text.method.checked?document.all.text.encode.select():document.all.text.decode.select()" value=" 全 选 "></form>
下面是一个显示所有全角半角的字体的查看例子
<style>BODY { FONT-SIZE: 9pt; PADDING-RIGHT: 0px; PADDING-LEFT: 0px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px;}input { FONT-SIZE: 9pt; height: 13pt;}</style><script>function showUni(min,max){ show.document.open(); show.document.writeln("<style>body{font-size:9pt;word-break:break-all;}</style>"); show.document.writeln(min + " - " + max + "<br><br>"); var i=0; for(i=min;i<=max;i++){  show.document.write("&#" + i + ";"); } show.document.close();}</script><input type=button value="半角"  onclick=showUni(32,126)><input type=button value="全角"  onclick=showUni(65281,65374)><input type=button value="中文1" onclick=showUni(19968,40869)><input type=button value="中文2" onclick=showUni(63744,64045)><input type=button value="日文平"  onclick=showUni(12353,12435)><input type=button value="日文片"  onclick=showUni(12449,12534)><input type=button value="韩文"  onclick=showUni(44032,55203)><br>自定义：<input name=min> - <input name=max><input type=button value="察看" onclick=showUni(parseInt(document.all.min.value),parseInt(document.all.max.value))><br><iframe src="about:blank" id=show width=100% height=70% scroll=no></iframe>
下面是一个查表(gb2312),转换gb2312到utf8的例子, 现在有iconv函数,这个已经没有太大的意义了,
<?function gb2utf8($gb){    if(!trim($gb))  return $gb;    $filename="gb2312.txt";    $tmp=file($filename);    $codetable=array();    while(list($key,$value)=each($tmp))          $codetable[hexdec(substr($value,0,6))]=substr($value,7,6);
    $utf8="";    while($gb) {        if (ord(substr($gb,0,1))>127) {          $this=substr($gb,0,2);          $gb=substr($gb,2,strlen($gb)-2);          $utf8.=u2utf8(hexdec($codetable[hexdec(bin2hex($this))-0x8080]));        }else{            $this=substr($gb,0,1);            $gb=substr($gb,1,strlen($gb)-1);            $utf8.=u2utf8($this);        }    }    return $utf8;}
function u2utf8($c){    $str="";    if ($c < 0x80) {         $str.=$c;    } else if ($c < 0x800) {         $str.=chr(0xC0 | $c>>6);         $str.=chr(0x80 | $c & 0x3F);    } else if ($c < 0x10000) {         $str.=chr(0xE0 | $c>>12);         $str.=chr(0x80 | $c>>6 & 0x3F);         $str.=chr(0x80 | $c & 0x3F);    } else if ($c < 0x200000) {         $str.=chr(0xF0 | $c>>18);         $str.=chr(0x80 | $c>>12 & 0x3F);         $str.=chr(0x80 | $c>>6 & 0x3F);         $str.=chr(0x80 | $c & 0x3F);    }    return $str;}
?>