private function pollExitCodePipe()
    {
        if (! isset($this->pipes[3])) {
            return;
        }

        $r = [$this->pipes[3]];
        $w = $e = null;

        $n = @stream_select($r, $w, $e, 0);

        if (1 !== $n) {
            return;
        }

        $data = fread($r[0], 8192);

        if (strlen($data) > 0) {
            $this->fallbackExitCode = (int) $data;
        }
    }
private function pollExitCodePipe()
    {
        if (! isset($this->pipes[3])) {
            return;
        }

        $r = [$this->pipes[3]];
        $w = $e = null;

        $n = @stream_select($r, $w, $e, 0);

        if (1 !== $n) {
            return;
        }

        $data = fread($r[0], 8192);

        if (strlen($data) > 0) {
            $this->fallbackExitCode = (int) $data;
        }
    }
private function pollExitCodePipe ( ) { if ( ! isset ( $ this -> pipes [ 3 ] ) ) { return ; } $ r = [ $ this -> pipes [ 3 ] ] ; $ w = $ e = null ; $ n = @ stream_select ( $ r , $ w , $ e , 0 ) ; if ( 1 !== $ n ) { return ; } $ data = fread ( $ r [ 0 ] , 8192 ) ; if ( strlen ( $ data ) > 0 ) { $ this -> fallbackExitCode = ( int ) $ data ; } }
Check the fourth pipe for an exit code.

This should only be used if --enable-sigchild compatibility was enabled.
Check the fourth pipe for an exit code .