Utilizing proc_open for Stream Handling in PHP

When using exec() in PHP, it can be beneficial to also check stderr in case of errors. While using php://stderr is an option, proc_open provides a comprehensive approach to handle both stderr and stdout streams separately.

Consider the following example:

// Initialize stream descriptors
$descriptorspec = [
    0 => ["pipe", "r"],  // stdin
    1 => ["pipe", "w"],  // stdout
    2 => ["pipe", "w"],  // stderr
];

// Execute the command
$process = proc_open('./test.sh', $descriptorspec, $pipes, dirname(__FILE__), null);

// Read from the output streams
$stdout = stream_get_contents($pipes[1]);
fclose($pipes[1]);

$stderr = stream_get_contents($pipes[2]);
fclose($pipes[2]);

// Output the results
echo "stdout:\n";
var_dump($stdout);

echo "stderr:\n";
var_dump($stderr);

By leveraging proc_open and the designated stream descriptors, you can effectively separate and capture the output from your PHP commands, allowing you to handle errors and other outputs appropriately.