How to Send Curl Request ?

To send a cURL request in PHP, you can use PHP’s built-in cURL functions. These functions allow you to interact with APIs or web services easily. Most PHP setups already include the cURL extension, so you don’t need to install anything extra. Here’s how it works:

1. Start cURL: Use curl_init() to start a new cURL session.
2. Set Options: Use curl_setopt() to set various options, like the URL to send the request to, the type of request (GET, POST, etc.), and the data to send.
3. Execute the Request: Use curl_exec() to send the request and get the response.
4. Check for Errors: Use curl_errno() or curl_error() to see if something went wrong.
5. Close cURL: Use curl_close() to end the session and free up resources.

Important curl_setopt() Parameters

Here are the most commonly used cURL options:

Option	Description	Example
CURLOPT_URL	Sets the URL for the request.	curl_setopt($ch, CURLOPT_URL, "https://example.com");
CURLOPT_RETURNTRANSFER	Returns the response as a string instead of outputting it directly.	curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
CURLOPT_POST	Indicates the request is a POST request.	curl_setopt($ch, CURLOPT_POST, true);
CURLOPT_POSTFIELDS	Sends data in the body of the request. Works for POST, PUT, PATCH, etc.	curl_setopt($ch, CURLOPT_POSTFIELDS, "key1=value1&key2=value2"); or curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode(['key' => 'value']));
CURLOPT_HTTPHEADER	Sets custom headers for the request.	curl_setopt($ch, CURLOPT_HTTPHEADER, ["Content-Type: application/json"]);
CURLOPT_USERPWD	Sends credentials for Basic Authentication in the format username:password.	curl_setopt($ch, CURLOPT_USERPWD, "user:pass");
CURLOPT_TIMEOUT	Sets a timeout (in seconds) for the request.	curl_setopt($ch, CURLOPT_TIMEOUT, 30);
CURLOPT_CUSTOMREQUEST	Specifies the request method (e.g., PUT, DELETE, PATCH) explicitly.	curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "DELETE");
CURLOPT_FOLLOWLOCATION	Follows redirects (if the server issues a 3xx redirect response).	curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
CURLOPT_SSL_VERIFYPEER	Verifies the server’s SSL certificate (use false for self-signed certificates, but not recommended in production).	curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
CURLOPT_SSL_VERIFYHOST	Verifies the hostname in the SSL certificate (set to 0 to disable, 2 to enforce).	curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
CURLOPT_HEADER	Includes the response headers in the output.	curl_setopt($ch, CURLOPT_HEADER, true);
CURLOPT_COOKIE	Sends cookies with the request.	curl_setopt($ch, CURLOPT_COOKIE, "name=value; othername=othervalue");
CURLOPT_COOKIEFILE	Specifies a file to read cookies from.	curl_setopt($ch, CURLOPT_COOKIEFILE, "/path/to/cookie.txt");
CURLOPT_COOKIEJAR	Specifies a file to save cookies to after the request.	curl_setopt($ch, CURLOPT_COOKIEJAR, "/path/to/cookie.txt");
CURLOPT_USERAGENT	Sets a custom User-Agent string for the request.	curl_setopt($ch, CURLOPT_USERAGENT, "MyApp/1.0");
CURLOPT_REFERER	Sets the Referer header for the request.	curl_setopt($ch, CURLOPT_REFERER, "https://example.com");
CURLOPT_VERBOSE	Outputs detailed debugging information.	curl_setopt($ch, CURLOPT_VERBOSE, true);
CURLOPT_HTTPAUTH	Sets the authentication method (e.g., CURLAUTH_BASIC, CURLAUTH_DIGEST).	curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
CURLOPT_PROXY	Specifies a proxy server to use for the request.	curl_setopt($ch, CURLOPT_PROXY, "http://proxyserver:8080");
CURLOPT_PROXYUSERPWD	Sends proxy authentication credentials in the format username:password.	curl_setopt($ch, CURLOPT_PROXYUSERPWD, "user:pass");
CURLOPT_ENCODING	Specifies the encoding to use for the request (e.g., gzip, deflate).	curl_setopt($ch, CURLOPT_ENCODING, "gzip");
CURLOPT_MAXREDIRS	Sets the maximum number of redirects to follow.	curl_setopt($ch, CURLOPT_MAXREDIRS, 10);

<?php
// Initialize cURL session
$ch = curl_init();

// Set the URL
curl_setopt($ch, CURLOPT_URL, "https://example.com/api");

// Set HTTP method
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");

// Add POST data
$data = json_encode([
    "name" => "John",
    "email" => "john@example.com"
]);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);

// Set headers
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    "Content-Type: application/json",
    "Authorization: Bearer YOUR_API_TOKEN"
]);

// Enable response return
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

// Set timeout
curl_setopt($ch, CURLOPT_TIMEOUT, 30);

// Follow redirects
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);

// SSL verification
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);

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

// Check for errors
if (curl_errno($ch)) {
    echo "Error: " . curl_error($ch);
} else {
    echo "Response: " . $response;
}

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