Using check_service to tell when a service is not installed

[ghost]

I'm testing SNClient at the moment and everything seems to be going well, but I have run into a bit of an issue with the check_service command and I'm not sure if this is intended or not.

If I'm using the check_process command, I can "upgrade" the result from unknown to critical if a process is not running, for example:

:/usr/local/nagios/libexec$ ./check_nrpe -H 172.31.100.1 -c check_process -a "process=winword"
UNKNOWN - check_process failed to find anything with this filter. |'count'=0;;;0 'rss'=0B;;;0 'virtual'=0B;;;0 'cpu'=0%;;;0

Now, if I add empty-syntax and empty-state, I can manually change this:

:/usr/local/nagios/libexec$ ./check_nrpe -H 172.31.100.1 -c check_process -a "process=winword" "empty-syntax=CRITICAL: Word not running" "empty-state=2"
CRITICAL: Word not running |'count'=0;;;0 'rss'=0B;;;0 'virtual'=0B;;;0 'cpu'=0%;;;0

Obviously, we wouldn't need to check if Word is running but this demonstrates the point. With check_service however, I cannot do the same thing:

:/usr/local/nagios/libexec$ ./check_nrpe -H 172.31.100.1 -c check_service -a "service=madeupservice"
UNKNOWN - failed to open service madeupservice: failed to find service name madeupservice: The specified service does not exist as an installed service.

Using the same empty-syntax and empty-state values:

:/usr/local/nagios/libexec$ ./check_nrpe -H 172.31.100.1 -c check_service -a "service=madeupservice" "empty-syntax=CRITICAL: Service not installed" "empty-state=2"
UNKNOWN - failed to open service madeupservice: failed to find service name madeupservice: The specified service does not exist as an installed service.

Is this intended functionality or could this be altered at all? The idea is that we would want to make sure we have a particular service installed on machines and this would be an easy way to check.

[sni]

One of the reasons is that it is way easier to retrieve the process table than the services. So in case of the check_process all processes are fetched and the process= argument is used as filter.
If nothing matches, the empty clause will be used.
In case of services, when there is a service argument, then snclient directly tries to open only this specific service and in case this doesn't work, it is treated as error, not as empty list.
Thinking about it, i don't think there is a generic solution for this, at least no easy one.
One idea might be to use the error message in the empty-message instead of bailing out. Then the
empty-message and the empty-state could be used and the original error message could be made available as macro.