The RCS output format is designed specifically for use by the Revision
Control System, which is a set of free programs used for organizing
different versions and systems of files. Use the
--rcs option to select this output format. It is like the
ed format (see Forward ed), but it can represent
arbitrary changes to the contents of a file because it avoids the
ed format's problems with lines consisting of a single
period and with incomplete lines. Instead of ending text sections with
a line consisting of a single period, each command specifies the number
of lines it affects; a combination of the
commands are used instead of
c. Also, if the second file ends
in a changed incomplete line, then the output also ends in an
Here is the output of
diff -n lao tzu (see Sample diff Input, for the complete contents of the two files):
The named is the mother of all things.
They both may be called deep and profound.
Deeper and more profound,
The door of all subtleties!