curl_init

(PHP 4 >= 4.0.2, PHP 5, PHP 7, PHP 8)

curl_initInitialize a cURL session

Description

curl_init(?string $url = null): CurlHandle|false

Initializes a new session and return a cURL handle for use with the curl_setopt(), curl_exec(), and curl_close() functions.

Parameters

url

If provided, the CURLOPT_URL option will be set to its value. You can manually set this using the curl_setopt() function.

Note:

The file protocol is disabled by cURL if open_basedir is set.

Return Values

Returns a cURL handle on success, false on errors.

Changelog

Version Description
8.0.0 On success, this function returns a CurlHandle instance now; previously, a resource was returned.
8.0.0 url is nullable now.

Examples

Example #1 Initializing a new cURL session and fetching a web page

<?php
// create a new cURL resource
$ch = curl_init();

// set URL and other appropriate options
curl_setopt($ch, CURLOPT_URL, "http://www.example.com/");
curl_setopt($ch, CURLOPT_HEADER, 0);

// grab URL and pass it to the browser
curl_exec($ch);

// close cURL resource, and free up system resources
curl_close($ch);
?>

See Also

add a note

User Contributed Notes 2 notes

up
1
NextgenThemes
1 year ago
This may be obvious, but:

Note that is MUCH faster to use use a single instance to make a series of curl requests rather than creating a new instance for each request.
up
-4
VictorWumble
7 months ago
NextgenThemes' note is applicable for very very limited situations. For completeness's sake, let's consider the following code snippet:

<?php

/*
Your localhost has a default Apache which simply returns "It works!"
*/

$repeatCount = 1000;

// begin section
// this section is slow

// call localhost, create new handle each time
$time = microtime(true);
foreach (
range(1, $repeatCount) as $ignored) {
$ch = curl_init("http://localhost");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);
// do something with the response
unset($response);
curl_close($ch);
}
unset(
$ch);
$elapsed = microtime(true) - $time;
echo
"Recreate curl handle, time taken: " . $elapsed . "\n";

// end section

// begin section
// this section is much faster

// call localhost, but reuse the handle
$time = microtime(true);
$ch = curl_init("http://localhost");
foreach (
range(1, $repeatCount) as $ignored) {
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);
// do something with the response
unset($response);
}
curl_close($ch);
$elapsed = microtime(true) - $time;
echo
"Reuse curl handle, time taken: " . $elapsed . "\n";

// end section

/*
Example output:
Recreate curl handle, time taken: 11.289301872253
Reuse curl handle, time taken: 0.53790807723999
*/

?>

The above code supports the claim by NextgenThemes, however the "send curl requests in sequence" method in general is unnecessarily slow because:
- network transfer time (e.g. 100ms)
- remote processing time (e.g. 50ms)
- usually, no need to send requests in specific sequence

So, in practice, when you need to send multiple curl requests at the same time, just use the curl_multi_init method. Don't consider the "send curl requests in sequence" method unless you have very very specific/special needs.
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