RCS version Control

The RCS (Revision Control System) derivative has two
SCCS (Source Code Control System)
CVS (Concurrent Versions System) is a GNU software package used primarily for the maintenance of source code in a multi-person development environment
Most software development companies now use SVN instead of CVS

1. ci Check In

# ci char.c

char.c,v  <--  char.c
new revision:1.2; previous revision:1.1
enter log message, Terminated with single ' or End of file:
>> include//note information
>>.
Done

2. Co check out

# Co CHAR.C//read-only Co

char.c,v-  char.c
revision 1.2
done

# co-l CHAR.C//Locking Co

char.c,v  -to CHAR.C
revision 1.3 (locked)
done

Only one user has Write permission

# co-l CHAR.C//co Failure char.c,v--CHAR.C co:char.c,v:revision 1.3 is already locked by
root.

3. Rlog
View a list of changes to a file

# rlog char.c

RCS file:char.c,v
working file:char.c
head:1.3
Branch:
locks:strict
Access List:
symbolic names:
keyword substitution:kv total
revisions:3; selected Revisions:3
description:< C10/>hello

4. Rcsdiff
See changes between two revisions

# rcsdiff-r1.1-r1.2 char.c
===========================================================
RCS file:char.c, V
Retrieving revision 1.1
retrieving revision 1.2
diff-r1.1-r1.2
1a2
> #include < stdio.h>//change