Using curl_close() to Properly Close cURL Sessions in PHP

cURL (Client URL Library) is a PHP extension for sending and receiving HTTP requests, offering features such as POST/GET requests, custom headers, and cookie handling. After completing a cURL request, the curl_close() function should be called to close the session and release resources.

The syntax of curl_close() is:

curl_close(resource $ch): void

Here $ch is a cURL handle created by curl_init() , representing an active cURL session. Calling curl_close($ch) terminates that session and frees associated resources.

Example usage:

// Create a cURL handle
$ch = curl_init();

// Set cURL options
curl_setopt($ch, CURLOPT_URL, "https://www.example.com");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

// Execute the request
$result = curl_exec($ch);

// Close the cURL session
curl_close($ch);

The example first creates a handle with curl_init() , sets the target URL and the option to return the response as a string, executes the request with curl_exec() , and finally releases the handle using curl_close() .

Closing a cURL session provides several advantages: it saves resources by releasing network connections, improves performance by reducing server load, and frees memory occupied by variables and caches. After a session is closed, the handle cannot be reused; a new handle must be created for additional requests.

Summary: The curl_close() function is essential for properly terminating PHP cURL sessions, preventing resource leaks, enhancing performance, and ensuring robust code. Understanding its syntax and proper usage, as demonstrated in the example, helps developers write efficient backend HTTP communication.