没有来自循环的输出

Question

I'm iterating over a huge array and it involves querying multiple APIs so to avoid data loss and timeout, I'm doing this:

for ($i = 0; $i < $count; $i++) {
  if ($i % 100 == 0) {
    echo 'processed: '.$i."
";
    // save to file
  }
}

... it works if the loop is a few hundred iterations during test and outputs processed ..., but nothing at all in prod environment during the script is running, it echos everything only after its done. I just want to avoid any timeouts incase it takes (and usually does) long.

Answer 1

PHP output is buffered; see here. If you flush the buffer (or turn buffering off), you'll see it happen in real-time.

As "belt and braces", if you really care about the output, I'd echo the $count before you even enter the loop.