Basic curl examples

Once you've compiled PHP with cURL support, you can begin using the cURL functions. The basic idea behind the cURL functions is that you initialize a cURL session using the curl_init(), then you can set all your options for the transfer via the curl_setopt(), then you can execute the session with the curl_exec().

Here is a simple example that uses the cURL functions to send a POST request:

Example #1 Using PHP's cURL module to send a POST request

<?php
$data = ['foo' => 'bar', 'baz' => 48];
$url = "http://www.example.com/handler.php";

$ch = curl_init($url);

// tell CURL to return the response instead of sending it to stdout
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

// set the POST data, corresponding method and headers
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($data));

// send the request and get the response
$response = curl_exec($ch);

if(curl_error($ch)) {
    // handle the error, or just
    throw new RuntimeException(curl_error($ch));
}

Another example that uses the cURL functions to send a raw JSON POST request:

Example #2 Using PHP's cURL module to send a JSON POST request

<?php
$post_data = ['foo' => 'bar', 'baz' => 48];
$url = "http://www.example.com/api/endpoint";

$ch = curl_init($url);

// tell CURL to return the response instead of sending it to stdout
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

// set the POST data and corresponding method
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($post_data));

// set the required header
curl_setopt($ch, CURLOPT_HTTPHEADER, ['Content-Type: application/json']);

// send the request and get the response
$response = curl_exec($ch);

if(curl_error($ch)) {
    // handle the error, or just
    throw new RuntimeException(curl_error($ch));
}

Here is another example that uses the cURL functions to fetch the example.com homepage into a file:

Example #3 Using PHP's cURL module to fetch the example.com homepage

<?php

$ch = curl_init("http://www.example.com/");
$fp = fopen("example_homepage.txt", "w");

curl_setopt($ch, CURLOPT_FILE, $fp);
curl_setopt($ch, CURLOPT_HEADER, 0);

curl_exec($ch);
if(curl_error($ch)) {
    fwrite($fp, curl_error($ch));
}
fclose($fp);