PHP curl_close() Function: Usage and Examples

Historically closes an easy cURL handle. This guide demonstrates its use in PHP code and explains when the result or side effect needs extra checks.

What It Does

Historically closes an easy cURL handle.

Syntax and Parameters

The examples below show a real call to curl_close with suitable arguments. Read the function call in context: its connection, handle, input data or other prerequisites are created before use.

Requirements: cURL extension; HTTP client and transfer-handling tools.

Compatibility and security: Deprecated since PHP 8.5; no effect on PHP 8.0+ object handles.

Example 1: Core Behavior

The first case demonstrates the precise handle or result type.

<?php
$ch = curl_init('https://api.example.test/health');
curl_setopt_array($ch, [CURLOPT_RETURNTRANSFER => true, CURLOPT_TIMEOUT => 3, CURLOPT_CONNECTTIMEOUT => 2]);
curl_close($ch);
echo "Legacy close called; PHP 8.0+ frees handle objects automatically.";

Observe the returned value or changed resource state. A successful function call can still require additional checks before a higher-level operation is considered successful.

Example 2: Alternative or Failure Case

The second case checks behavior under a different configuration or request.

<?php
$ch = curl_init('https://api.example.test/products');
curl_setopt_array($ch, [CURLOPT_RETURNTRANSFER => true, CURLOPT_TIMEOUT => 4, CURLOPT_CONNECTTIMEOUT => 2]);
curl_close($ch);
echo "Legacy close called; PHP 8.0+ frees handle objects automatically.";

Compare the different inputs, environment assumptions or result checks. Do not use a transport-level success value as proof that all business-level requirements were met.

Practical Example: Applying the Rule

The practical case shows how to inspect the operation outcome instead of assuming success.

<?php
$ch = curl_init('https://api.example.test/orders');
curl_setopt_array($ch, [CURLOPT_RETURNTRANSFER => true, CURLOPT_TIMEOUT => 5, CURLOPT_CONNECTTIMEOUT => 2]);
curl_close($ch);
echo "Legacy close called; PHP 8.0+ frees handle objects automatically.";

In an application, convert low-level failures into controlled responses and log only non-sensitive diagnostic context.

Important Behavior and Edge Cases

From PHP 8.0 the CurlHandle object manages its own lifetime; curl_close has no effect and is deprecated in PHP 8.5.

TLS validation, bounded timeouts and a destination allowlist are essential for network requests involving potentially untrusted targets.

Comparison with Related Functions or Patterns

Common Beginner Mistakes

Key Takeaways

• Historically closes an easy cURL handle.
• From PHP 8.0 the CurlHandle object manages its own lifetime; curl_close has no effect and is deprecated in PHP 8.5.
• unset($handle) releases a PHP reference to a handle instead.

Select this API or pattern based on its documented behavior and the trust boundaries in your own application, and test all external integrations against their actual deployments.