| kill | status | start | stop | meaning                                            |
|------+--------+-------+------+----------------------------------------------------|
|    0 |      0 |     0 |    0 | no request                                         |
|    0 |      0 |     0 |    1 | stop only                                          |
|    0 |      0 |     1 |    0 | start only                                         |
|    0 |      0 |     1 |    1 | start + stop (error)                               |
|    0 |      1 |     0 |    0 | status only                                        |
|    0 |      1 |     0 |    1 | status + stop                                      |
|    0 |      1 |     1 |    0 | status + start                                     |
|    0 |      1 |     1 |    1 | status + start + stop (error, show status          |
|    1 |      0 |     0 |    0 | kill only                                          |
|    1 |      0 |     0 |    1 | kill + stop (error, kill)                          |
|    1 |      0 |     1 |    0 | kill + start (error, kill)                         |
|    1 |      0 |     1 |    1 | kill + start + stop (error, kill)                  |
|    1 |      1 |     0 |    0 | kill + status                                      |
|    1 |      1 |     0 |    1 | kill + status + stop (error, kill, status)         |
|    1 |      1 |     1 |    0 | kill + status + start (error, kill)                |
|    1 |      1 |     1 |    1 | kill + status + start + stop (error, kill, status) |