PHP socket_set_timeout Function

last modified April 4, 2025

The PHP socket_set_timeout function sets timeout values for socket operations. It’s essential for network programming to prevent hanging.

Basic Definition

socket_set_timeout configures timeout values for socket streams. It affects operations like reading, writing, and connecting.

Syntax: socket_set_timeout(resource $socket, int $seconds, int $microseconds = 0): bool. Returns true on success, false on failure. Works with stream sockets.

Setting Basic Socket Timeout

This example demonstrates setting a simple timeout for socket operations.

basic_timeout.php

<?php

declare(strict_types=1);

$socket = fsockopen(“example.com”, 80); if ($socket === false) { die(“Connection failed”); }

// Set 5 second timeout socket_set_timeout($socket, 5);

// Perform socket operations…

fclose($socket);

This sets a 5-second timeout for all operations on the socket. After this period, operations will timeout if not completed. Prevents indefinite blocking.

Precise Timeout with Microseconds

This shows how to set a timeout with microsecond precision for exact timing.

microsecond_timeout.php

<?php

declare(strict_types=1);

$socket = fsockopen(“example.com”, 80); if ($socket === false) { die(“Connection failed”); }

// Set 2.5 second timeout (2 seconds + 500000 microseconds) socket_set_timeout($socket, 2, 500000);

// Read operation with precise timeout $data = fread($socket, 1024);

fclose($socket);

This sets a 2.5 second timeout by combining seconds and microseconds. Useful when you need more precise control over timeout durations.

Checking for Timeout Condition

This example demonstrates how to check if a timeout occurred during operations.

check_timeout.php

<?php

declare(strict_types=1);

$socket = fsockopen(“example.com”, 80); if ($socket === false) { die(“Connection failed”); }

socket_set_timeout($socket, 3);

$data = fread($socket, 1024);

$info = stream_get_meta_data($socket); if ($info[’timed_out’]) { echo “Socket operation timed out”; } else { echo “Operation completed successfully”; }

fclose($socket);

After socket operations, we check the stream metadata for timeout status. This helps identify if operations failed due to timeout conditions.

Different Timeouts for Read/Write

This shows how to set different timeout values for read and write operations.

rw_timeouts.php

<?php

declare(strict_types=1);

$socket = fsockopen(“example.com”, 80); if ($socket === false) { die(“Connection failed”); }

// Set read timeout (5 seconds) socket_set_timeout($socket, 5);

// Perform read operations…

// Set write timeout (2 seconds) socket_set_timeout($socket, 2);

// Perform write operations…

fclose($socket);

Different operations may need different timeout values. This example shows how to adjust timeouts between read and write operations.

Handling Slow Connections

This demonstrates using timeouts to handle slow or unreliable connections.

slow_connection.php

<?php

declare(strict_types=1);

function fetchWithRetry($host, $port, $retries = 3) { $timeout = 2; // Start with 2 second timeout

for ($i = 0; $i < $retries; $i++) {
    $socket = fsockopen($host, $port);
    if ($socket === false) continue;
    
    socket_set_timeout($socket, $timeout);
    
    $data = fread($socket, 1024);
    $info = stream_get_meta_data($socket);
    
    if (!$info['timed_out']) {
        fclose($socket);
        return $data;
    }
    
    fclose($socket);
    $timeout *= 2; // Double timeout for next retry
}

return false;

}

$data = fetchWithRetry(“example.com”, 80);

This implements a retry mechanism with increasing timeouts. Useful for handling temporary network issues or slow connections.

Best Practices

• Reasonable Timeouts: Set appropriate values for your use case

• Error Handling: Always check for timeout conditions

• Resource Cleanup: Close sockets properly after use

• Context Awareness: Adjust timeouts based on network conditions

Source

PHP socket_set_timeout Documentation

This tutorial covered the PHP socket_set_timeout function with practical examples for network programming and timeout management.

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.

List all PHP Network Functions.