Often when I use cURL in a script it takes several seconds to return a page. Is the script using 100% CPU during this time? I ask because I want to have a loop that requests lots of pages (over a hundred) using cURL, but because cURL takes a second or two per page, if it uses 100% CPU during this time then that would be really bad for the server!

Could the website you're asking for just be slow? Keep in mind that your server and theirs have to both respond to get a fast response.

Try it on a site like Google. Google is lightning fast, so it'll help calculate how fast your own server is.

Yes, it's definitely possible that it's slow, and that's why the cURL requests take several seconds. I can try with another website like Google, as you suggested, but what I'm wondering is whether the script takes 100% of the server CPU while it's waiting for the page, or if it doesn't take processor during that time?

I've never messed around with cron. By doing some quick Googles (is that a word?) I've found that cron uses 'very little' CPU, which is a good thing, otherwise your website (and whole server!) would be bogged down running a cron job every day. You wouldn't want to take up your entire server's resources, which you most likely don't own yourself, to just check a simple URL, which you wouldn't.

Cron and CURL are two completely different things. The answer is the same for either one however:

No they are not using 100% of your CPU.

There is an easy way to test this:

PHP Code:

$start = time();
while(time() - $start < 5){}

$content = file_get_contents('http://google.com');

$start = time();
while(time() - $start < 5){} 


I'm using file_get_contents instead of cURL but the concept is the same. You'll notice 100% utilization (on one processor) for about five seconds, then a drop, then 100% for another five seconds.

What's happening is the process is asleep while it is waiting for an HTTP response.

What's happening is the process is asleep while it is waiting for an HTTP response.

Exactly what I was trying to figure out, thanks!!