Trigger other services on PPS activity
- Publishers
- Any app
- Subscribers
- coreServices
Note:
This type of object is known as a
server object, a special PPS object designed for point-to-point communication between
a server and one or more clients. For details, see
"Server objects" in the
QNX Persistent Publish/Subscribe Developer's
Guide.
Overview
You can use the
ppsnetd service to watch any PPS object and have a client executable run when activity occurs on the watched object.
Note:
The ppsnetd service cannot be running when the watch command is invoked. If it is running, you must stop the service, invoke watch, and then start the service again.
Message/response format
Commands sent to the /pps/services/ppsnetd/control object are of the form:
msg::command_string\nid::ID_number\ndat:json:{JSON_data}
Responses always reflect the command_string and ID_number that were sent in the message, along with any errors:
res::command_string\nid::ID_number\ndat:json:{JSON_data}\nerr::errno_number\nerrstr::error_description
Commands
| msg:: |
id:: |
dat:json: |
| watch |
Number |
{"object":"<path_to_object>","exec":"<path_to_executable>"} |
| start |
Number |
n/a |
| stop |
Number |
n/a |
Responses
| res:: |
id:: |
dat:json: |
err:: |
errstr:: |
| command (watch, start, or stop)
|
Number (whatever was sent in id::)
|
n/a |
errno_number |
as appropriate |