The CLI version of hdhomerun_config supports running an automatic channel scan.
The CLI version of hdhomerun_config can be downloaded from:
http://www.silicondust.com/forum/viewtopic.php?t=1923
Usage:
hdhomerun_config FFFFFFFF scan
For example:
OTA ATSC:
hdhomerun_config FFFFFFFF scan /tuner0
hdhomerun_config FFFFFFFF scan /tuner1
Digital Cable:
hdhomerun_config FFFFFFFF scan /tuner0
hdhomerun_config FFFFFFFF scan /tuner1