I am developing a terminal on web app for personal use and using Ratchet for the socket server.
And It is working fine with simple commands like ls etc.
But when I run commands like ping it just doesn't send the content of stdout and stderr to the socket client However even in these commands I am able to see that commands live output in terminal.
Here is my implementation
<?php
use Ratchet\MessageComponentInterface;
use Ratchet\ConnectionInterface;
// ini_set('display_errors', 1);
// ini_set('display_startup_errors', 1);
// error_reporting(E_ALL);
require 'vendor/autoload.php'; // Ensure you have Ratchet installed
class TerminalServer implements MessageComponentInterface {
protected $clients;
private array $open_processes;
public function __construct() {
$this->open_processes = [];
$this->clients = new \SplObjectStorage;
}
public function onOpen(ConnectionInterface $conn) {
echo "New connection\n";
$this->clients->attach($conn);
}
static function get_output_json( string $message , array $opts = []){
return json_encode( [ 'data' => $message , 'opts' => $opts ] );
}
private function command_exec(ConnectionInterface &$from , string $command){
$descriptorspec = [
0 => ["pipe", "r"], // stdin
1 => ["pipe", "w"], // stdout
2 => ["pipe", "w"], // stderr
];
$process = proc_open($command, $descriptorspec, $pipes);
$this->open_processes[] = $process;
if (is_resource($process)) {
// Close the input pipe, since we're not sending any input
fclose($pipes[0]);
// Set the pipes to non-blocking mode
stream_set_blocking($pipes[1], false);
stream_set_blocking($pipes[2], false);
while (true) {
$output = stream_get_contents($pipes[1]);
$error = stream_get_contents($pipes[2]);
if ($output) {
$string_to_send = $this->get_output_json($output);
echo "Out: $string_to_send\n";
$from->send($string_to_send);
}
if ($error) {
$string_to_send = $this->get_output_json($error);
echo "Err: $string_to_send\n";
$from->send($string_to_send);
}
flush();
// Check if the process is still running
$status = proc_get_status($process);
if (!$status['running']) {
break;
}
// Small delay to prevent busy-waiting
usleep(100000); // 100ms
}
// Close pipes and process
fclose($pipes[1]);
fclose($pipes[2]);
$return_value = $this->command_end($process);
$from->send($this->get_output_json("Command ended with code $return_value\n", ['exit' => true]));
} else {
$from->send($this->get_output_json("Command failed to execute", ['exit' => true]));
}
}
/**end or terminate a command and return the exit code */
public static function command_end( $proc ) :int|false {
if( !is_resource($proc) ){
return false;
}
$status = proc_get_status( $proc );
if( $status['running'] === true ) {
proc_terminate($proc , SIGINT);
return SIGINT;
} else {
return proc_close($proc);
}
}
public function onMessage(ConnectionInterface $from, $msg) {
$command = trim($msg);
// $allowedCommands = ['ls -l', 'pwd', 'whoami'];
if (true || in_array($command, $allowedCommands)) {
$this->command_exec($from , $command);
} else {
$from->send($this->get_output_json("Command not allowed.\r\n"));
}
}
public function onClose(ConnectionInterface $conn) {
echo "Connection closed\n";
foreach ($this->open_processes as $p) {
var_dump($p);
proc_close($p);
}
$this->clients->detach($conn);
}
public function onError(ConnectionInterface $conn, \Exception $e) {
echo "Connection closed because error\n";
$conn->close();
}
}
$app = new Ratchet\App('localhost', 2222);
$app->route('/terminal', new TerminalServer, ['*']);
echo "No errors so far\n";
$app->run();
I have tried making the command exit after reading 10 lines by changing the command_exec function and it sends the output all at once after it is exited
private function command_exec(ConnectionInterface &$from , string $command){
$descriptorspec = [
0 => ["pipe", "r"], // stdin
1 => ["pipe", "w"], // stdout
2 => ["pipe", "w"], // stderr
];
$process = proc_open($command, $descriptorspec, $pipes);
$this->open_processes[] = $process;
if (is_resource($process)) {
// Close the input pipe, since we're not sending any input
fclose($pipes[0]);
// Set the pipes to non-blocking mode
stream_set_blocking($pipes[1], false);
stream_set_blocking($pipes[2], false);
$i = 0;//count line read
while (true) {
$output = stream_get_contents($pipes[1]);
$error = stream_get_contents($pipes[2]);
if ($output) {
$string_to_send = $this->get_output_json($output);
echo "Out: $string_to_send\n";
$from->send($string_to_send);
$i++;
if( $i > 10 ){
break;
}
}
if ($error) {
$string_to_send = $this->get_output_json($error);
echo "Err: $string_to_send\n";
$from->send($string_to_send);
}
flush();
// Check if the process is still running
$status = proc_get_status($process);
if (!$status['running']) {
break;
}
// Small delay to prevent busy-waiting
usleep(100000); // 100ms
}
// Close pipes and process
fclose($pipes[1]);
fclose($pipes[2]);
$return_value = $this->command_end($process);
$from->send($this->get_output_json("Command ended with code $return_value\n", ['exit' => true]));
} else {
$from->send($this->get_output_json("Command failed to execute", ['exit' => true]));
}
}
I was able to find what exactly was the problem about , here
So it was clear that the $from->send($data) method was waiting for ping command to be executed and It has to be done in a non blocking way as shown in the same page
So I changed the command_exec like following
private function command_exec(ConnectionInterface &$from, string $command){
$descriptorspec = [
0 => ["pipe", "r"], // stdin
1 => ["pipe", "w"], // stdout
2 => ["pipe", "w"], // stderr
];
$process = proc_open($command, $descriptorspec, $pipes);
println("Created process");
$this->add_to_open_processes( $from , $process );
if (is_resource($process)) {
fclose($pipes[0]);
$stdout_promise = new Deferred();
$stderr_promise = new Deferred();
$command_end_callback = function () use ($from, $pipes, $process) {
println("all promise resolved");
array_map( 'fclose' , array_filter( [$pipes[1] , $pipes[2]] , 'is_resource') );
$return_value = $this->command_end($process);
$this->send_ln( $from , "Command ended with code $return_value");
};
$main_promise = \React\Promise\all([$stdout_promise->promise() , $stderr_promise->promise()]);
$main_promise->then($command_end_callback);
if (is_resource($pipes[1]) && 'stream' === get_resource_type($pipes[1])) {
println("stdout is stream");
$stdout_stream = new Stream($pipes[1]);
$this->add_to_open_streams( $from , $stdout_stream);
$stdout_stream->on('data', function($data) use ($from){
$string_to_send = $this->get_output_json($data);
println("Out: $string_to_send");
$from->send($string_to_send);
});
$stdout_stream->on('end', function() use( $stdout_promise ) {
$stdout_promise->resolve(true);
});
} else {
$stdout_promise->resolve(true);
}
if (is_resource($pipes[2]) && 'stream' === get_resource_type($pipes[2])) {
println("stderr is stream");
$stderr_stream = new Stream($pipes[2]);
$this->add_to_open_streams( $from , $stderr_stream);
$stderr_stream->on('data', function($data) use ($from){
$string_to_send = $this->get_output_json($data);
println("Err: $string_to_send");
$from->send($string_to_send);
});
$stderr_stream->on('end', function() use( $stderr_promise ) {
$stderr_promise->resolve(true);
});
} else {
$stderr_promise->resolve(true);
}
}
}
I have used \React\Promise\all to end the process of command after STDOUT and STDERR has ended.