php转码函数

<?php

class Charset {
//UTF-8 转GB编码
static public function utf82gb($utfstr)
{
if(function_exists('iconv'))
{
return iconv('utf-8','gbk//ignore',$utfstr);
}
global $UC2GBTABLE;
$okstr = "";
if(trim($utfstr)=="")
{
return $utfstr;
}
if(empty($UC2GBTABLE))
{
$filename = "data/gb2312-utf8.dat";
$fp = fopen($filename,"r");
while($l = fgets($fp,15))
{
$UC2GBTABLE[hexdec(substr($l, 7, 6))] = hexdec(substr($l, 0, 6));
}
fclose($fp);
}
$okstr = "";
$ulen = strlen($utfstr);
for($i=0;$i<$ulen;$i++)
{
$c = $utfstr[$i];
$cb = decbin(ord($utfstr[$i]));
if(strlen($cb)==8)
{
$csize = strpos(decbin(ord($cb)),"0");
for($j=0;$j < $csize;$j++)
{
$i++; $c .= $utfstr[$i];
}
$c = utf82u($c);
if(isset($UC2GBTABLE[$c]))
{
$c = dechex($UC2GBTABLE[$c]+0x8080);
$okstr .= chr(hexdec($c[0].$c[1])).chr(hexdec($c[2].$c[3]));
}
else
{
$okstr .= "&#".$c.";";
}
}
else
{
$okstr .= $c;
}
}
$okstr = trim($okstr);
return $okstr;
}

//GB转UTF-8编码
static public function gb2utf8($gbstr)
{
if(function_exists('iconv'))
{
return iconv('gbk','utf-8//ignore',$gbstr);
}
global $CODETABLE;
if(trim($gbstr)=="")
{
return $gbstr;
}
if(empty($CODETABLE))
{
$filename = "data/gb2312-utf8.dat";
$fp = fopen($filename,"r");
while ($l = fgets($fp,15))
{
$CODETABLE[hexdec(substr($l, 0, 6))] = substr($l, 7, 6);
}
fclose($fp);
}
$ret = "";
$utf8 = "";
while ($gbstr != '')
{
if (ord(substr($gbstr, 0, 1)) > 0x80)
{
$thisW = substr($gbstr, 0, 2);
$gbstr = substr($gbstr, 2, strlen($gbstr));
$utf8 = "";
@$utf8 = u2utf8(hexdec($CODETABLE[hexdec(bin2hex($thisW)) - 0x8080]));
if($utf8!="")
{
for ($i = 0;$i < strlen($utf8);$i += 3)
$ret .= chr(substr($utf8, $i, 3));
}
}
else
{
$ret .= substr($gbstr, 0, 1);
$gbstr = substr($gbstr, 1, strlen($gbstr));
}
}
return $ret;
}

//Unicode转utf8
static public function u2utf8($c)
{
for ($i = 0;$i < count($c);$i++)
{
$str = "";
}
if ($c < 0x80)
{
$str .= $c;
}
else if ($c < 0x800)
{
$str .= (0xC0 | $c >> 6);
$str .= (0x80 | $c & 0x3F);
}
else if ($c < 0x10000)
{
$str .= (0xE0 | $c >> 12);
$str .= (0x80 | $c >> 6 & 0x3F);
$str .= (0x80 | $c & 0x3F);
}
else if ($c < 0x200000)
{
$str .= (0xF0 | $c >> 18);
$str .= (0x80 | $c >> 12 & 0x3F);
$str .= (0x80 | $c >> 6 & 0x3F);
$str .= (0x80 | $c & 0x3F);
}
return $str;
}

//utf8转Unicode
static public function utf82u($c)
{
switch(strlen($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;
}
}

//Big5码转换成GB码
static public function big52gb($Text)
{
if(function_exists('iconv'))
{
return iconv('big5','gbk//ignore',$Text);
}
global $BIG5_DATA;
if(empty($BIG5_DATA))
{
$filename = "data/big5-gb.dat";
$fp = fopen($filename, "rb");
$BIG5_DATA = fread($fp,filesize($filename));
fclose($fp);
}
$max = strlen($Text)-1;
for($i=0;$i<$max;$i++)
{
$h = ord($Text[$i]);
if($h>=0x80)
{
$l = ord($Text[$i+1]);
if($h==161 && $l==64)
{
$gbstr = "　";
}
else
{
$p = ($h-160)*510+($l-1)*2;
$gbstr = $BIG5_DATA[$p].$BIG5_DATA[$p+1];
}
$Text[$i] = $gbstr[0];
$Text[$i+1] = $gbstr[1];
$i++;
}
}
return $Text;
}

//GB码转换成Big5码
static public function gb2big5($Text)
{
if(function_exists('iconv'))
{
return iconv('gbk','big5//ignore',$Text);
}
global $GB_DATA;
if(empty($GB_DATA))
{
$filename = "data/gb-big5.dat";
$fp = fopen($filename, "rb");
$gb = fread($fp,filesize($filename));
fclose($fp);
}
$max = strlen($Text)-1;
for($i=0;$i<$max;$i++)
{
$h = ord($Text[$i]);
if($h>=0x80)
{
$l = ord($Text[$i+1]);
if($h==161 && $l==64)
{
$big = "　";
}
else
{
$p = ($h-160)*510+($l-1)*2;
$big = $GB_DATA[$p].$GB_DATA[$p+1];
}
$Text[$i] = $big[0];
$Text[$i+1] = $big[1];
$i++;
}
}
return $Text;
}

//unicode url编码转gbk编码函数
static public function UnicodeUrl2Gbk($str)
{
//载入对照词典
if(!isset($GLOBALS['GbkUniDic']))
{
$fp = fopen('data/gbk-unicode.dat','rb');
while(!feof($fp))
{
$GLOBALS['GbkUniDic'][bin2hex(fread($fp,2))] = fread($fp,2);
}
fclose($fp);
}

//处理字符串
$str = str_replace('$#$','+',$str);
$glen = strlen($str);
$okstr = "";
for($i=0; $i < $glen; $i++)
{
if($glen-$i > 4)
{
if($str[$i]=='%' && $str[$i+1]=='u')
{
$uni = strtolower(substr($str,$i+2,4));
$i = $i+5;
if(isset($GLOBALS['GbkUniDic'][$uni]))
{
$okstr .= $GLOBALS['GbkUniDic'][$uni];
}
else
{
$okstr .= "&#".hexdec('0x'.$uni).";";
}
}
else
{
$okstr .= $str[$i];
}
}
else
{
$okstr .= $str[$i];
}
}
return $okstr;
}
}
?>