curl_init

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

curl_init — Inizializza una sessione CURL

Descrizione

curl_init(string $url = null): resource

Inizializza una nuova sessione e restituisce un gestore cURL da usare con le funzioni curl_setopt(), curl_exec(), e curl_close().

Elenco dei parametri

url: Se viene fornita, l'opzione CURLOPT_URL verrà impostata al suo valore. Si può impostare manualmente quest'ultima, usando la funzione curl_setopt().

Nota:
Il protocollo file viene disabilitato da cURL se viene impostato open_basedir.

Valori restituiti

Restituisce un gestore cURL in caso di successo, false in caso di errore.

Esempi

Example #1 Inizializzare una nuova sessione cURL e scarica una pagina web

<?php
// crea una nuova risorsa cURL
$ch = curl_init();

// imposta l'URL e le altre opzioni appropriate
curl_setopt($ch, CURLOPT_URL, "http://www.example.com/");
curl_setopt($ch, CURLOPT_HEADER, 0);

// imposta l'URL e lo passa al browser
curl_exec($ch);

// chiude la risorsa cURL, e libera le risorse di sistema
curl_close($ch);
?>

Vedere anche:

curl_close() - Chiude una sessione cURL
curl_multi_init() - Restituisce un nuovo handle multiplo cURL

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User Contributed Notes 2 notes

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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.

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VictorWumble ¶

1 year 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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