How to wait for a process executed by proc_open() in php?

Question

please after reading this question , do not say that it is copied.I have already searched on web but none of the solution worked for me.

Wha

Answer 1

Here's my go at it (reading both stdout and stderr (hopefully) without deadlocks):

class ExecResult {
    public $returnValue;
    public $stdoutBuffer;
    public $stderrBuffer;
}

class WtfPhpWhyIHaveToDoEverythingMyself {
    public static function exec($proc, $argv) {
        $cwd = getcwd();
        $env = [];

        $procAndArgv = count($argv) > 0 ?
            $proc . ' ' . implode(' ', self::escapeArgvs($argv)) :
            $proc;

        $pipes = null; // will get filled by proc_open()

        $result = new ExecResult();

        $processHandle = proc_open(
            $procAndArgv,
            [
                0 => ['pipe', 'r'], // read/write is from child process's perspective
                1 => ['pipe', 'w'],
                2 => ['pipe', 'w']
            ],
            $pipes,
            $cwd,
            $env);

        $stdin = $pipes[0];
        $stdout = $pipes[1];
        $stderr = $pipes[2];

        fclose($stdin);

        stream_set_blocking($stdout, false);
        stream_set_blocking($stderr, false);

        $outEof = false;
        $errEof = false;

        do {
            $read = [ $stdout, $stderr ]; // [1]
            $write = null; // [1]
            $except = null; // [1]

            // [1] need to be as variables because only vars can be passed by reference

            stream_select(
                $read,
                $write,
                $except,
                1, // seconds
                0); // microseconds

            $outEof = $outEof || feof($stdout);
            $errEof = $errEof || feof($stderr);

            if (!$outEof) {
                $result->stdoutBuffer .= fgets($stdout);
            }

            if (!$errEof) {
                $result->stderrBuffer .= fgets($stderr);
            }
        } while(!$outEof || !$errEof);

        fclose($stdout);
        fclose($stderr);

        $result->returnValue = proc_close($processHandle);

        return $result;
    }

    private static function escapeArgvs($argv) {
        return array_map(function ($item){
            return escapeshellarg($item);
        }, $argv);
    }
}

$result = WtfPhpWhyIHaveToDoEverythingMyself::exec('/var/www/html/hello.sh', [
    'arg 1',
    'arg 2',
]);

var_dump($result);

/*
object(ExecResult)#1 (3) {
  ["returnValue"]=> int(0)
  ["stdoutBuffer"]=>
  string(45) "var1 = arg 1
var2 = arg 2
"
  ["stderrBuffer"]=>
  string(0) ""
}
*/

I am really disappointed that with PHP, you have to write all the plumbing yourself. For example node.js has got your back covered with simple child_process.spawn()