RCS HELP

File:		rcs.help
Author:		course (send problems to walton@das)
Version:	2

Purpose: RCS implements a system for storing past and
present versions of a file "foo" in another file
"foo,v".  The second file is usually put in the RCS
subdirectory of the directory containing "foo", so its
fuller pathname is "RCS/foo,v".  In storing many
versions of "foo" in "foo,v", RCS stores mostly just the
differences between versions, thus saving much storage
space compared to a normal file system.

RCS is very useful for backing up files in case you
accidentally delete them.  It is also useful for
seeing what changes you recently made.

mkdir RCS	Makes the RCS subdirectory of the
		current directory.  DO THIS FIRST,
		before checking any files in.

ci -l file1 file2 ...
		Checkin (i.e. back up) the files.
		The current versions of the files are
		not touched, only backups are made
		(but DO NOT FORGET THE -l).

rcsdiff file1 file2 ...
		Output the differences between the
		files in the current directory and the
		last version of the files checked in.

co -l file1 file2 ...
		Checkout (retrieve from backup) the
		files (in case you lost them or did a
		ci without the -l).


Infrequently used commands:
------------------------

rlog file	Print info on versions contained in
		"RCS/file,v".  Versions are called
		"revisions".

rcsdiff -r1.n file
		Output the differences between the file
		in the current directory and version
		("revision") 1.n in "RCS/file,v".

ci file1 file2 ...
		Checkin (i.e. back up) the files,
		deleting the files from the current
		directory.  This command is typically
		given only by accident, and requires a
		co -l (see above) to recover the file in
	        the current directory).

co -r1.n file	Checkout (retrieve) version (revision)
		1.n from "RCS/file,v".  CLOBBERS "file"
		in the current directory.  Does no
		locking if -l not given.

rcs -l file	Lock file (see below for explanation).



More Detailed Explanation of RCS:
--------------------------------


"checkin"	A technical term meaning to move a file
		"foo" from the current directory into
		its RCS storage file "RCS/foo,v".  The
		file becomes the last version put into
		"RCS/foo,v", and the file is deleted
		from the current directory.

"checkout"	A technical term meaning to copy a file
		"foo" (actually, a version of "foo", by
		default the latest version) from its
		RCS storage file "RCS/foo,v" to the
		current directory.

"locked"	A technical term.  "RCS/foo,v"
		contains a bit that indicates whether
		(the latest version of) "foo" is locked
		or unlocked.  If "foo" is locked, it
		has been checked out with the intention
		of writing it, and it is OK to check it
		back in.  If "foo" is unlocked, it is
		not permitted to check it back in (it
		may have been checked out just for the
		purpose of reading it).

ci -l file1 file2 ...
		Check the files in, then check them
		right back out and make them locked and
		writable.  May be used to check in files
		never checked in before (so
		"RCS/filen,v" does not yet exist).

co -l file1 file2 ...
		Check files out and make them locked
		and writable.

rcs -l file	Lock file.  If the file is locked by
		some other person, but you can write
		the RCS directory, this command will
		allow you to break the lock of the
		other person but will email that person.