In a new post from the Delicious Brains site Peter Tasker looks at how WordPress makes HTTP requests with the help of the cURL functionality in PHP.

cURL is the workhorse of the modern internet. As its tagline says, cURL is a utility piece of software used to ‘transfer data with urls‘. According to the cURL website, the library is used by billions of people daily in everything from cars and television sets, to mobile phones. It’s the networking backbone of thousands of applications and services. Unsurprisingly, it’s also a core utility used by WordPress’ own Requests API as well as our own WP Migrate DB Pro.

If you’re curious about the power of the cURL library, how it works with WordPress and what to watch out for (especially on macOS), then you’re in the right place.

He starts by giving a bit of background on what cURL is and some examples of how its used to make requests. He then talks about the cURL integration with PHP via an extension and provides a simple code example fetching an endpoint from the httpbin.org site. With that background defined he moves into the main focus of the article - how cURL and PHP combine in the WordPress WP_Http class and Requests handling to make HTTP requests to remote (or local) resources. Code examples are included showing how to put these pieces to work in a custom script and includes some common issues you might see during your HTTP request development.