PHP: wait 2 minute until next, is this right?

$timenow = tim开发者_StackOverflow中文版e();
if($lasttime - 120 > $timenow)

Is this right? to check if there has been 2 minutes ( 120 seconds ) since lasttime?

It's either $lasttime + 120 > $timenow or $timenow - 120 > $lasttime.

Imagine both times start with 0 and the "timenow" grows with every second. With that mindtrick you should get it.

if (($lasttime+120)>=time())

I suggest you to calculate number of elapsed seconds first, then compare it to your needs:

$elapsed_time = time() - $lasttime; ## time() is increasing
if ($elapsed_time > 120) {
    ## more then 2 minutes passed
}
else {
    ## it's not time yet
}

This should help to understand your code later.

Use

$time_start = microtime(true);
//Do whatever
if ($time_start-microtime(true)>=2000){
    //Yup, 2 minutes
}