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.
(PHP 4 >= 4.0.2, PHP 5, PHP 7, PHP 8)
curl_init — Inicializar uma sessão cURL
Inicializa uma nova sessão e retorna um identificador cURL para uso com as funções curl_setopt(), curl_exec(), e curl_close().
url
Se fornecida, a opção CURLOPT_URL
será definida
com seu valor.Você pode definir isso manualmente usando a função
curl_setopt().
Nota:
O protocolo
file
é desativado no cURL se open_basedir estiver definido.
Retorna um identificador cURL em caso de sucesso, false
sobre erros.
Versão | Descrição |
---|---|
8.0.0 | No caso de sucesso, a função retorna uma instância de CurlHandle; anteriormente era retornado um resource. |
8.0.0 |
url agora permite null.
|
Exemplo #1 Inicializando uma nova sessão cURL e buscando uma página da web
<?php
// Cria um novo recurso cURL
$ch = curl_init();
// Configura a URL e opções
curl_setopt($ch, CURLOPT_URL, "http://www.example.com/");
curl_setopt($ch, CURLOPT_HEADER, 0);
// Obtém os dados
curl_exec($ch);
// Fecha o recurso cURL e libera recursos interos
curl_close($ch);
?>
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.
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.