获取整条字符串所有汉字拼音首字母的函数

function pinyin_long($zh){  //获取整条字符串所有汉字拼音首字母
    $zh=gainChinese($zh,100);//提取中文
    $ret = "";
    $s1 = iconv("UTF-8","gb2312", $zh);
    $s2 = iconv("gb2312","UTF-8", $s1);
    if($s2 == $zh){$zh = $s1;}
    for($i = 0; $i < strlen($zh); $i++){
        $s1 = substr($zh,$i,1);
        $p = ord($s1);
        if($p > 160){
            $s2 = substr($zh,$i++,2);
            $ret .= getFirstCharter($s2);
        }else{
            $ret .= $s1;
        }
    }
    return $ret;
}

function gainChinese($str='',$length='2')
    {
        $count = 0;//
        $str_count = strlen($str);//字符个数
        $result = '';
        if ($str_count>0) {
            for($i=0;$i<$str_count;$i++){
                $str_i = mb_substr($str,$i,1,'utf-8');//获取字符串中的第$i个字符
                if(preg_match('/^[x{4e00}-x{9fa5}]+$/u',$str_i) && $count<$length){
                    $result .= $str_i;
                    $count ++;
                }
            }
        }
        return $result;
    }