What is the common error message when using fsockopen in PHP and how can it be resolved?

The common error message when using fsockopen in PHP is "Connection timed out" or "Unable to connect to remote server". This error typically occurs when the server is not reachable or the connection is being blocked by a firewall. To resolve this issue, you can increase the timeout value for the fsockopen function or check if there are any firewall restrictions blocking the connection.

$fp = fsockopen("example.com", 80, $errno, $errstr, 10);
if (!$fp) {
    echo "Error: $errstr ($errno)";
} else {
    // Connection successful, proceed with sending/receiving data
    fclose($fp);
}