It would be nice if Orage could be externally stimulated to do the equivalent of File -> Exchange data -> Import/Export -> Save (Export). This would facilitate "single click" synchronising of calendar data to mobile phone (at the same time as synchronising contacts data, non-calendar notes etc. from other programs). At simplest, perhaps a signal such as SIGUSR could trigger export using the default settings; a fully featured implementation would allow specification of the target file and all/named appointments.
This is very good idea.
This is now in Orage 4.8.1.4 available in git. Added startup parameter: --export (-e) file [appointment...] without appointment list, all appointments are exported to file. A handy way to get appointment list ids is by dragging them from event list window.
Implemented in 4.8.2