Software Engineering                                     Jim Murphy
CSCI-112                                                 Fall 2001
LESSON 14
Configuration Management can use some sort of tool to keep
track of various changes to various version of software, design
documents, documentation or any other kind of text file.
On unix RCS (Revision Control System) can be very helpful
for this - the man command can help you find out about what
is supported but here are a list of related programs.
man -k rcs
ci(1)                   - check in RCS revisions
co(1)                   - check out RCS revisions
ident(1)                - identify RCS keyword strings in files
rcs(1)                  - change RCS file attributes
rcsclean(1)             - clean up working files
rcsdiff(1)              - compare RCS revisions
rcsfile(5)              - format of RCS file
rcsintro(1)             - introduction to RCS commands
rcsmerge(1)             - merge RCS revisions
rlog(1)  - print log messages and other information about RCS files

As a simple example suppose I need to update the graduate
student requirements file as maintained on the gradinfo web
page to reflect the change last year of the Department Chair
and the Graduate Advisor - first check out the file as locked
guzzler 40> co -l Requirements
RCS/Requirements,v  -->  Requirements
revision 1.1 (locked)
done

Then use vi to make the changes in Chair and Grad Advisor
and then check the file back in again with:
guzzler 42> ci Requirements
RCS/Requirements,v  <--  Requirements
new revision: 1.2; previous revision: 1.1
enter log message, terminated with single '.' or end of file:
>> Changed Chair and Grad Advisor
>> .
done
The log message can be as many lines as you like and you do
not need to worry about someone else checking out the file
while you are editing so that after you write back your changes
they might write over it with changes of their own destroying
yours - the locked check out prevents this
Be sure to check the file back out unlocked to make it available:
guzzler 56> co Requirements
RCS/Requirements,v  -->  Requirements
revision 1.2
done