The chans to join are followed by the keys, both in comma delimited fashion. Empty fields for no keys...
If you wanted to join #a,#b,#c and both channels #a and #c have keys but not #b
-j #a,#b,#c keyforA,,keyforC
Now say chans #a and #b need keys
-j #a,#b,#c keyforA,keyforB
and only #c
-j #a,#b,#c ,,keyforC
