Usage: cdif [-Bvn] [-A #] [-C #] [-D #] [-I #] [-[bwcu]] file1 file2
       cdif [-rcs] [-q] [-rrev1 [-rrev2]] [cdif options] file
       cdif [cdif options] [diff-output-file]
Options:
	-B	byte compare
	-v	use video standout (default for tty)
	-n	use nroff style overstrike (default for non-tty)
	-b	ignore trailing blank
	-w	ignore whitespace
	-c[#]	context diff
	-u[#]	unified diff (if diff has -u option)
	-e #	expression of `word' (default is '\w+')
	-A, -C, -D (Append, Change, Delete) takes one of
		vso: video standout	vul: video underline
		vbd: video bold		bd:  nroff style overstrike
		ul:  nroff style underline
		or any sequence or sequences separated by comma
	-I	specify string to be shown on insertion point
		Following strings have special meanings.
		vbar:	print vertical bar at the point
		caret:	print caret under the point
	-diff=command
		specify any diff command