PHP curl_share_close Function

last modified April 11, 2025

The PHP curl_share_close function closes a cURL share handle. It's used to clean up shared resources between multiple cURL handles. This function frees all memory associated with the share handle.

Basic Definition

The curl_share_close function closes a cURL share handle created with curl_share_init(). It takes the share handle as its only parameter and returns nothing.

Syntax: curl_share_close(CurlShareHandle $share_handle): void. After calling this function, the share handle cannot be used anymore. Always close share handles when done to free resources.

Basic Shared Handle Usage

This example demonstrates creating and closing a basic cURL share handle.

basic_share_close.php

<?php

declare(strict_types=1);

$sh = curl_share_init();

// Configure shared options
curl_share_setopt($sh, CURLSHOPT_SHARE, CURL_LOCK_DATA_COOKIE);

// Use the share handle with multiple cURL handles...

curl_share_close($sh);

This code creates a share handle, sets it to share cookies between handles, and then closes it. The share handle would typically be used with multiple cURL handles before closing.

Sharing Cookies Between Handles

This example shows how to share cookies between multiple cURL handles.

cookie_sharing.php

<?php

declare(strict_types=1);

$sh = curl_share_init();
curl_share_setopt($sh, CURLSHOPT_SHARE, CURL_LOCK_DATA_COOKIE);

$ch1 = curl_init();
curl_setopt($ch1, CURLOPT_URL, "https://example.com/login");
curl_setopt($ch1, CURLOPT_SHARE, $sh);

$ch2 = curl_init();
curl_setopt($ch2, CURLOPT_URL, "https://example.com/profile");
curl_setopt($ch2, CURLOPT_SHARE, $sh);

// Execute requests...

curl_close($ch1);
curl_close($ch2);
curl_share_close($sh);

We create a share handle to share cookies between two cURL handles. This allows the second request to maintain the session from the first. All handles and the share handle are properly closed.

Sharing DNS Cache

This example demonstrates sharing DNS cache between multiple requests.

dns_sharing.php

<?php

declare(strict_types=1);

$sh = curl_share_init();
curl_share_setopt($sh, CURLSHOPT_SHARE, CURL_LOCK_DATA_DNS);

$ch1 = curl_init();
curl_setopt($ch1, CURLOPT_URL, "https://api.example.com/v1/users");
curl_setopt($ch1, CURLOPT_SHARE, $sh);

$ch2 = curl_init();
curl_setopt($ch2, CURLOPT_URL, "https://api.example.com/v1/posts");
curl_setopt($ch2, CURLOPT_SHARE, $sh);

// Execute requests...

curl_close($ch1);
curl_close($ch2);
curl_share_close($sh);

The share handle is configured to share DNS cache between requests. This can improve performance when making multiple requests to the same domain. All resources are properly cleaned up.

Sharing Multiple Data Types

This example shows how to share multiple data types between handles.

multi_share.php

<?php

declare(strict_types=1);

$sh = curl_share_init();
curl_share_setopt($sh, CURLSHOPT_SHARE, CURL_LOCK_DATA_COOKIE | CURL_LOCK_DATA_DNS | CURL_LOCK_DATA_SSL_SESSION);

$ch1 = curl_init();
curl_setopt($ch1, CURLOPT_URL, "https://secure.example.com");
curl_setopt($ch1, CURLOPT_SHARE, $sh);

$ch2 = curl_init();
curl_setopt($ch2, CURLOPT_URL, "https://secure.example.com/profile");
curl_setopt($ch2, CURLOPT_SHARE, $sh);

// Execute requests...

curl_close($ch1);
curl_close($ch2);
curl_share_close($sh);

We share cookies, DNS cache, and SSL sessions between handles. This is useful for maintaining sessions and improving performance. The bitwise OR operator combines multiple sharing options.

Error Handling with Shared Handles

This example demonstrates proper error handling with shared handles.

error_handling.php

<?php

declare(strict_types=1);

$sh = curl_share_init();

if ($sh === false) {
    die("Failed to initialize share handle");
}

if (!curl_share_setopt($sh, CURLSHOPT_SHARE, CURL_LOCK_DATA_COOKIE)) {
    curl_share_close($sh);
    die("Failed to set share option");
}

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://example.com");
curl_setopt($ch, CURLOPT_SHARE, $sh);

// Execute request...

if (curl_errno($ch)) {
    echo "cURL error: " . curl_error($ch);
}

curl_close($ch);
curl_share_close($sh);

We check for errors when creating and configuring the share handle. If any operation fails, we clean up resources before exiting. This prevents resource leaks in case of errors.

Best Practices

Cleanup: Always close share handles when done.
Error Handling: Check for errors when creating handles.
Sharing Scope: Only share what's needed for performance.
Thread Safety: Share handles are not thread-safe.
Lifetime: Keep share handle alive while in use.

Source

PHP curl_share_close Documentation

This tutorial covered the PHP curl_share_close function with practical examples showing its usage for shared cURL resources.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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