php字符编码转换代码

<?php教程
/**
 * utf8转gbk
 * @param $utfstr
 */
function utf8_to_gbk($utfstr) {
 global $UC2GBTABLE;
 $okstr = '';
 if(empty($UC2GBTABLE)) {
  $filename = CODETABLEDIR.'gb-unicode.table';
  $fp = fopen($filename, 'rb');
  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];
   }
   $c = utf8_to_unicode($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;
}
/**
 * gbk转utf8
 * @param $gbstr
 */
function gbk_to_utf8($gbstr) {
 global $CODETABLE;
 if(empty($CODETABLE)) {
  $filename = CODETABLEDIR.'gb-unicode.table';
  $fp = fopen($filename, 'rb');
  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 = unicode_to_utf8(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;
}
/**
 * 繁体转简体
 * @param  $Text
 */
function big5_to_gbk($Text) {
 global $BIG5_DATA;
 if(empty($BIG5_DATA)) {
  $filename = CODETABLEDIR.'big5-gb.table';
  $fp = fopen($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;
}
/**
 * 简体转繁体
 * @param  $Text
 */
function gbk_to_big5($Text) {
 global $GB_DATA;
 if(empty($GB_DATA)) {
  $filename = CODETABLEDIR.'gb-big5.table';
  $fp = fopen($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转utf8
 * @param  $c
 */
function unicode_to_utf8($c) {
 $str = '';
 if($c < 0x80) {
  $str .= $c;
 } elseif($c < 0x800) {
  $str .= (0xC0 | $c >> 6);
  $str .= (0x80 | $c & 0x3F);
 } elseif($c < 0x10000) {
  $str .= (0xE0 | $c >> 12);
  $str .= (0x80 | $c >> 6 & 0x3F);
  $str .= (0x80 | $c & 0x3F);
 } elseif($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
 * @param  $c
 */
function utf8_to_unicode($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;
 }
}
/**
 * Ascii转拼音
 * @param $asc
 * @param $pyarr
 */
function asc_to_pinyin($asc,&$pyarr) {
 if($asc < 128)return chr($asc);
 elseif(isset($pyarr[$asc]))return $pyarr[$asc];
 else {
  foreach($pyarr as $id => $p) {
   if($id >= $asc)return $p;
  }
 }
}
/**
 * gbk转拼音
 * @param $txt
 */
function gbk_to_pinyin($txt) {
 if(CHARSET != 'gbk') {
  $txt = iconv(CHARSET,'GBK',$txt);
 } 
 $l = strlen($txt);
 $i = 0;
 $pyarr = array();
 $py = array();
 $filename = CODETABLEDIR.'gb-pinyin.table';
 $fp = fopen($filename,'r');
 while(!feof($fp)) {
  $p = explode("-",fgets($fp,32));
  $pyarr[intval($p[1])] = trim($p[0]);
 }
 fclose($fp);
 ksort($pyarr);
 while($i<$l) {
  $tmp = ord($txt[$i]);
  if($tmp>=128) {
   $asc = abs($tmp*256+ord($txt[$i+1])-65536);
   $i = $i+1;
  } else $asc = $tmp;
  $py[] = asc_to_pinyin($asc,$pyarr);
  $i++;
 }
 return $py;
}