--filter --exclfilter re.search - may need addition to documentation

Hi!

I have been trying to use the --filter and --exclfilter options (which the documentation says uses re.search to include or exclude multiple terms but cannot seem to figure out how to do it. Maybe it is not possible as I see Python also has a re.findall.

Any advice on how this works would be appreciated! Frederick

[jblance]

added an example to usage.md

[frederickjh]

Thanks! That worked.

$ /usr/local/bin/mpp-solar -p /dev/mppsolar/direct/0 -P PI30MAX -b 2400 --getstatus --filter "pv|battery"                  4021ms  [Fri Dec  9 10:58:14 AM]
Command: QPIGS - General Status Parameters inquiry
------------------------------------------------------------
Parameter                     	Value           Unit
battery_voltage               	52.3           	V   
battery_charging_current      	0              	A   
battery_capacity              	81             	%   
pv1_input_current             	0.0            	A   
pv1_input_voltage             	0.0            	V   
battery_voltage_from_scc      	0.0            	V   
battery_discharge_current     	5              	A   
is_battery_voltage_to_steady_while_charging	0              	bool
battery_voltage_offset_for_fans_on	0              	10mV
pv1_charging_power

Might be a good idea to add that to the documentation.