正则 截取字符串A 和 B 之间的内容

Dalvik\/2.1.0 (Linux; U; Android 12; SM-M215F Build\/SP1A.210812.016)
Dalvik\/2.1.0 (Linux; U; Android 11; Infinix X689 Build\/RP1A.200720.011)
Android 是固定
Build是固定的

preg_match_all("/(?<=Android)[\s\S]+(?=Build)/", $_SERVER['HTTP_USER_AGENT'], $reg_phone_arr);
preg_match_all("/(?<=Android)[\s\S]+(?=MIUI)/", $_SERVER['HTTP_USER_AGENT'], $reg_phone_arr2);

 正向肯定预查 
?<=Android 匹配Android后面的字符

if(count($reg_phone_arr[0]) > 0 ){
    if(isset($reg_phone_arr[0][0])){
        $reg_phone_arr =  explode(';',$reg_phone_arr[0][0]);
        if($reg_phone_arr[1]){
            $phoneModel  = $reg_phone_arr[1];
        }
    }

}
if(count($reg_phone_arr2[0]) > 0 ){
    if(isset($reg_phone_arr2[0][0])){
        $reg_phone_arr2 =  explode(';',$reg_phone_arr2[0][0]);
        if($reg_phone_arr2[1]){
            $phoneModel  = $reg_phone_arr2[1];
        }
    }

}