Does anybody know the most efficient way with PHP or Javascript to connect to a web server, to get the Last-Modified time of a JavaScript file? Either from the "Last-Modified" response header or some other method that doesn't involve downloading the whole remote file? I tried PHP's filemtime()
, but I was getting some errors.
- Asked
- Updated
- Viewed
- 14.1k times
8 Answers
-
Votes
-
Oldest
-
Latest
- Answered
- Updated
https://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html#sec9.4
https://www.php.net/manual/en/function.curl-setopt.php
You're looking for CURLOPT_NOBODY
Just out of curiosity, which error(s) was filemtime giving you?
- Answered
- Updated
Thanks, I didn't think of using HEAD.
I wrote a curl function that just connects to whatever URL I give it, and gets the headers. However, I don't know how to get JUST the last-modified header? It's in there if I just print the raw result, but not if I use curl_getinfo(). I need to pull out the last-modified header and then convert it to a nix timestamp, but surely there's gotta be a way to do it without some sort of preg-match function and text to int, date conversion that I don't even know how to do.
<?php
function check_url($url) {
$c = curl_init();
curl_setopt($c, CURLOPT_URL,$url);
curl_setopt($c, CURLOPT_HEADER,1);//Include Header In Output
curl_setopt($c, CURLOPT_NOBODY,1);//Set to HEAD & Exclude body
curl_setopt($c, CURLOPT_RETURNTRANSFER,1);//No Echo/Print
curl_setopt($c, CURLOPT_TIMEOUT,5);//5 seconds max, to get the HEAD header.
$cURL_RESULT = curl_exec($c);
if($cURL_RESULT !== FALSE)
{
return print_r(curl_getinfo($c),TRUE);
}
return FALSE;
}?>
I still can't figure out how to get the Last-Modified header in timestamp format. I'm not sure if it's slower/faster either.
- Answered
- Updated
strtotime() - Is that what you need?
- Answered
- Updated
That's exactly what I needed. Thanks. Shows how much I convert dates from HTTP headers, 🤣 .
I found a solution to my problem. Maybe it will help one of you guys. I installed the PHP PECL HTTP extension, and wow is it nice. This is an example of getting the status code & last-modified header/timestamp of some Google Javascripts.
<?php
try {
$pool = new HttpRequestPool(
new HttpRequest('http://pagead2.googlesyndication.com/pagead/show_ads.js', HttpRequest::METH_HEAD),
new HttpRequest('http://www.google-analytics.com/ga.js', HttpRequest::METH_GET)
);
$pool->send();
foreach($pool as $request) {
printf("%s is %s (%d) Last Modified: %s (%s)\n<br />",
$request->getUrl(),
$request->getResponseCode() ? 'alive' : 'not alive',
$request->getResponseCode(),
$request->getResponseHeader('Last-Modified'),
strtotime($request->getResponseHeader('Last-Modified'))
);
}
} catch (HttpException $e) {
echo $e;
}
?>
Apparently google analytics will return a 405, if you run a HEAD request to it, so I had to make it a GET request, sucks though, cause I think that still downloads the file AND it's throwing random "last-modified" dates at me, I think it's cause they have multiple servers or something though.
I also need to figure out how to close the connection it opens though. It's not closing them.
-
0Awesome 😁 Glad you found the solution. — Bogey
- Answered
- Updated
new HttpRequest('http://pagead2.googlesyndication.com/pagead/show_ads.js', HttpRequest::METH_HEAD),
new HttpRequest('http://www.google-analytics.com/ga.js', HttpRequest::METH_GET)
raises eyebrow
What are you up to ?
-
0WRONG 🙂 — PolishHurricane
- Answered
- Updated
Well, I used to host google adsense/analytics JavaScript locally, because it speeds things up. But they do modify their scripts every once in a while, and they have been modifying them a lot lately. So I temporarily stopped hosting them locally on my website. However, I noticed a few things...
With google adsense/analytics hosted locally, I managed a YSlow score of 93 on a good load, which isn't bad for a site with adsense/analytics on it, because they still run images/scripts on the google/doubleclick servers, even if the main JavaScript files are hosted locally. But when I linked to the JavaScript files externally. It knocked my score down to 70.
I noticed it can add (depending on what ads/stuff you get in 1 load), usually...
- Around 6 external JavaScript files. (It used to be 3 or 4 on average, it seems they've added more)
- Multiple images/other files
- All of the included files have no "far future Expires or cache-control: max-age header:"
- Some of the JS isn't minified. But usually just a 3 line doubleclick.net file they include (talk about a waste of an HTTP request).
So I just programmed a script, where if the local adsense/analytics JavaScript file hasn't been modified in the past 24 hours, it will send a request to google for those 2 JavaScript files using the PHP PECL HTTP extension, and if the 'Last-Modified' header of googles JavaScript files is newer (among a few other checks), it will save the content to my local JavaScript files, with a little PHP to give it the proper content type headers (incase google changes them, which they have).
At first I was going to use a HEAD request, then if they were modified, run a GET request to grab the JavaScript. However...
- Analytics doesn't allow HEAD requests (I get an HTTP 405 code)
- And I figured it was too much of an issue running a HEAD request, then a GET request for adsense because I was having problems.
So I just stuck with 1 GET request for each. The script is done, but I'm still playing with how to close the 2 connections from my server it opens, I'm gonna do that after I eat dinner.
I figured I'd just include the google js updater into my main site content with this...
<?php
if((rand()&100) % 100 == 0) //this should hopefully only run 1/100th of the time
{
//update google files
}?>
- Answered
- Updated
I think you're being misled by yslow in this situation, though not intentionally.
There's a VERY good chance that the Google JS is going to already be cached in the visitors browser when they get to you. If you host it, there's a 100% chance that they will have to download it on their first visit.
I would ignore the yslow recomendations in this case.
- Answered
- Updated
Yeah I don't mind that, but it causes so many problems, including lagging my site if the Google server is slower, which happens a lot. Lately once in a while the ads haven't been loading either.
By any chance do you guys know how to close a connection using the PHP PECL HttpRequest class?
The connection was in an "ESTABLISHED" state on my server after my script finished. But, I managed to get the connection into "CLOSE_WAIT" state on my server by sending "Connection: close" with the HTTP header. However I still can't get the connection to close at all.