PHP 实用小方法01-字符截取，保留两端文字，中间用...连接

/**
 * 文字过长，截取前后两端文字，中间部分用...连接
 * @param string $string 要处理的文字
 * @param int $max 文字长度
 * @param string $rep 文字中间连接符
 */
function strCutMiddleWord($string, $max = 50, $rep = '...') {
    $strlen = strlen($string);
    // 文字数量多少
    $wordslen = mb_strlen($string,"UTF-8");
    if ($strlen <= $max || $wordslen <= $max) return $string;
    $lengthtokeep = $max - strlen($rep);
    if ($lengthtokeep <= 0) return $string;
    $start = 0;
    $end = 0;

    if (($lengthtokeep % 2) == 0) {
        $start = $lengthtokeep / 2;
        $end = $start;
    } else {
        $start = intval($lengthtokeep / 2);
        $end = $start + 1;
    }

    $i = $start;
    $tmp_string = $string;
    while ($i < $strlen) {
        if (isset($tmp_string[$i]) and $tmp_string[$i] == ' ') {
            $tmp_string = mb_substr($tmp_string, 0, $i, 'utf-8') . $rep;
            $return = $tmp_string;
        }
        $i++;
    }
    $i = $end;
    $tmp_string = strrev ($string);
    while ($i < $strlen) {
        if (isset($tmp_string[$i]) and $tmp_string[$i] == ' ') {
            $tmp_string = mb_substr($tmp_string, 0, $i, 'utf-8');
            $return .= strrev ($tmp_string);
        }
        $i++;
    }
    return mb_substr($string, 0, $start) . $rep . mb_substr($string, - $end);
}