php：根据中文裁减字符串函数方法

define(CHARSET, 'UTF-8'); // 系统默认编码

/**

* 根据中文裁减字符串

* @param $string - 字符串

* @param $length - 长度

* @param $doc - 缩略后缀

* @return 返回带省略号被裁减好的字符串

*/

function cutstr( $string, $length, $dot = '...' ) {

if ( strlen( $string )

return $string;

}

$pre = chr( 1 );

$end = chr( 1 );

$string = str_replace( array( '&', '"', '' ), array( $pre . '&' . $end, $pre . '"' . $end, $pre . '' . $end ), $string );

$strcut = '';

if ( strtolower( CHARSET ) == 'utf-8' ) {

$n = $tn = $noc = 0;

while ( $n

$t = ord( $string[$n] );

if ( $t == 9 || $t == 10 || (32

$tn = 1;

$n++;

$noc++;

} elseif ( 194

$tn = 2;

$n += 2;

$noc += 2;

} elseif ( 224

$tn = 3;

$n += 3;

$noc += 2;

} elseif ( 240

$tn = 4;

$n += 4;

$noc += 2;

} elseif ( 248

$tn = 5;

$n += 5;

$noc += 2;

} elseif ( $t == 252 || $t == 253 ) {

$tn = 6;

$n += 6;

$noc += 2;

} else {

$n++;

}

if ( $noc >= $length ) {

break;

}

}

if ( $noc > $length ) {

$n -= $tn;

}

$strcut = substr( $string, 0, $n );

} else {

for ( $i = 0; $i

$strcut .= ord( $string[$i] ) > 127 ? $string[$i] . $string[++$i] : $string[$i];

}

}

$strcut = str_replace( array( $pre . '&' . $end, $pre . '"' . $end, $pre . '' . $end ), array( '&', '"', '' ), $strcut );

$pos = strrpos( $strcut, chr( 1 ) );

if ( $pos !== false ) {

$strcut = substr( $strcut, 0, $pos );

}

return $strcut . $dot;

}