Today, we’re going to explore the cURL extension in PHP, which allows you to make HTTP requests from your code.
Often you need to communicate with external websites in your day-to-day PHP development. Whether it’s calling third-party REST APIs to fetch data or downloading resources from an external website, you want a library which allows you to do it effortlessly.
In PHP, there are different methods you can use to connect and communicate with different types of servers. One of the easiest ways is to use the file_get_contents function to read remote files. On the other hand, you can also use sockets to implement client-server communication. In this article, though, we’re going to discuss the cURL extension in detail, with real-world examples.
cURL stands for client URLs, and it’s a library which allows you to send and receive information with the URL syntax. In fact, it leverages the libcurl library, created by Daniel Stenberg, which allows you to connect to and communicate with many different types of servers with many different types of protocols. Apart from HTTP and HTTPS, the libcurl library also supports protocols like FTP, Gopher, Telnet, DICT, File, and LDAP.
From the next section onwards, we'll go through a couple of real-world examples to demonstrate how you can use cURL functions in PHP.
Real-World Examples
In this section, we’ll build real-world examples to demonstrate various cURL functions in PHP.
How to Download Files Using cURL in PHP
Reading or downloading remote files is one of the most common use cases for cURL. This is accomplished by a cURL GET request, which we’ll discuss in this section.
Go ahead and create the curl_read_file.php file with the following contents.