Mastering PHP cURL: How to Perform GET and POST Requests

CURL is a command‑line tool that transfers data using URL syntax and supports protocols such as HTTP, FTP and TELNET. PHP provides a cURL extension, allowing developers to perform HTTP requests directly from scripts.

The basic workflow in PHP consists of four steps: initialize with curl_init(), set options via curl_setopt(), execute the request with curl_exec(), and finally close the handle with curl_close(). The most commonly used options include the request URL, return transfer flag, header inclusion, request method and POST fields.

GET request example

$ch = curl_init();
curl_setopt($ch, curlOPT_URL, "http://www.eer3.com");
curl_setopt($ch, curlOPT_RETURNTRANSFER, 1);
curl_setopt($ch, curlOPT_HEADER, 0);
$output = curl_exec($ch);
curl_close($ch);
print_r($output);

POST request example

$url = "http://localhost/web_services.php";
$post_data = array("username" => "uname", "key" => "123456");
$ch = curl_init();
curl_setopt($ch, curlOPT_URL, $url);
curl_setopt($ch, curlOPT_RETURNTRANSFER, 1);
curl_setopt($ch, curlOPT_POST, 1);
curl_setopt($ch, curlOPT_POSTFIELDS, $post_data);
$output = curl_exec($ch);
curl_close($ch);
print_r($output);

When the response is JSON, it can be decoded into an associative array with json_decode($output, true), or into an object by omitting the second parameter.