<?php
define('CODETABLEDIR', dirname(__FILE__).DIRECTORY_SEPARATOR.'encoding'.DIRECTORY_SEPARATOR);
/**
 * 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;
}
/**
 * 
 * 截取字符串函数
 * @param 要截取的字符 $str
 * @param 开始位置 $start
 * @param 截取长度 $length
 * @param 编码 $charset
 * @param 超出尾部加上true默认加...，或输入要加上的字符 $suffix 
 */
function get_substr($str, $start=0, $length, $charset = CHARSET, $suffix = true)
{
	if(function_exists("mb_substr")){
		return mb_substr($str, $start, $length, $charset);
	}elseif(function_exists('iconv_substr')) {
		return iconv_substr($str,$start,$length,$charset);
	}
	$re['utf-8']  = "/[/x01-/x7f]|[/xc2-/xdf][/x80-/xbf]|[/xe0-/xef][/x80-/xbf]{2}|[/xf0-/xff][/x80-/xbf]{3}/";
	$re['gb2312'] = "/[/x01-/x7f]|[/xb0-/xf7][/xa0-/xfe]/";
	$re['gbk']	  = "/[/x01-/x7f]|[/x81-/xfe][/x40-/xfe]/";
	$re['big5']	  = "/[/x01-/x7f]|[/x81-/xfe]([/x40-/x7e]|/xa1-/xfe])/";
	preg_match_all($re[$charset], $str, $match);
	$slice = join("",array_slice($match[0], $start, $length));
	if($suffix) {
		if (is_bool($suffix)){
			return $slice."…";
		}else{
			return $slice.$suffix;
		}
		
	}
	return $slice;
}
?>