Cowburn — Find me on GitHub and StackOverflow.

Server download speed using PHP cURL

I've been meaning to add a few snippets of code to the blog, just to archive them to save my own memory but who knows, they may prove useful to someone else.

This particular one uses cURL to get an idea of the download speed of your web server but is more a demonstration of grabbing the extra information about a cURL transaction which people rarely take a look at. The code was first posted in a similar topic on Sitepoint.

PHP Snippet

<?php error_reporting(E_ALL | E_STRICT);

// Initialize cURL with given url
$url = 'http://download.bethere.co.uk/images/61859740_3c0c5dbc30_o.jpg';
$ch = curl_init($url);

curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_USERAGENT, 'Sitepoint Examples (thread 581410; http://www.sitepoint.com/forums/showthread.php?t=581410)');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 2);
curl_setopt($ch, CURLOPT_TIMEOUT, 60);

set_time_limit(65);

$execute = curl_exec($ch);
$info = curl_getinfo($ch);

// Time spent downloading, I think
$time = $info['total_time'] 
      - $info['namelookup_time'] 
      - $info['connect_time'] 
      - $info['pretransfer_time'] 
      - $info['starttransfer_time'] 
      - $info['redirect_time'];


// Echo friendly messages
header('Content-Type: text/plain');
printf("Downloaded %d bytes in %0.4f seconds.\n", $info['size_download'], $time);
printf("Which is %0.4f mbps\n", $info['size_download'] * 8 / $time / 1024 / 1024);
printf("CURL said %0.4f mbps\n", $info['speed_download'] * 8 / 1024 / 1024);

echo "\n\ncurl_getinfo() said:\n", str_repeat('-', 31 + strlen($url)), "\n";
foreach ($info as $label => $value)
{
    printf("%-30s %s\n", $label, $value);
}

Example Output

Downloaded 6576848 bytes in 16.2153 seconds.
Which is 3.0944 mbps
CURL said 3.0755 mbps


curl_getinfo() said:
---------------------------------------------------------------------------------------------
url                            http://download.bethere.co.uk/images/61859740_3c0c5dbc30_o.jpg
content_type                   image/jpeg
http_code                      200
header_size                    263
request_size                   198
filetime                       -1
ssl_verify_result              0
redirect_count                 0
total_time                     16.314966
namelookup_time                0.000287
connect_time                   0.021524
pretransfer_time               0.021595
size_upload                    0
size_download                  6576848
speed_download                 403117
speed_upload                   0
download_content_length        6576848
upload_content_length          0
starttransfer_time             0.056275
redirect_time                  0

As you can see from the example output, there's a miniature treasure trove of information about the cURL transaction which is particularly helpful for the purposes of reporting on the speed and other statistics of the download. Do you ever bother to take a look at the information from your cURL calls?