The line editing uses a subset of emacs editing keys, familiar to anyone
using unix shells like bash and tcsh.  Where appropriate the corresponding
cursor keys are supported.

^A	Home		Begining of line
^E	End/Copy	End of line
^B	Left		Cursor left
^F	Right		Cursor right
^D			Delete right
<-|	Delete		Delete left
^K			Delete to end of line
^U			Delete entire line
^P	Up		Previous line
^N	Down		Next line

The last two cycle through the command history in a fairly obvious way.
The command history stores up to 256 bytes of input, which seems to be
enough for typical usage.