Often cURL in PHP is used to download whole webpages, another great use is downloading and saving images.

Using cURL to save images is used over the file_put_content(file_get_contents()) because you can apply more parameters to the request most important being able to set a user agent.

With cURL I can state “who I am” when I make the request for the image.

You can hide your scraping bot and pretend you’re just a regular web user…

curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US)");

Or have some fun:

curl_setopt($ch, CURLOPT_USERAGENT, "Grabbing image in 3, 2, 1... Thanks");

Obviously a regular user wouldn’t be hitting as many requests in little time as a scraping bot would.

By using

curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_BINARYTRANSFER, 1);

The image is returned as a raw binary string and not outputted.

curl_setopt($ch, CURLOPT_HEADER, false);

Means no header is in the output.

$fp = fopen($save_as, 'x');
fwrite($fp, $raw_data);
fclose($fp);

Handles the saving of the raw image data into the actual viewable image file.

The full code is:

<?php
$image_url = 'https://website.com/img/1234.jpg';
$save_as = 'img/1234.jpg';
$ch = curl_init($image_url);
curl_setopt($ch, CURLOPT_HEADER, false);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_BINARYTRANSFER, 1);
curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US)");
$raw_data = curl_exec($ch);
curl_close($ch);
$fp = fopen($save_as, 'x');
fwrite($fp, $raw_data);
fclose($fp);