Introduction to using RCS on Discworld. RCS is a revision control system. It does two very valuable things for us on Discworld. Firstly it locks files so that only one person at a time can edit them, hence no more 'who overwrote my changes?' messages. The second thing it does is to keep a record of every change made to a file so that you can see who changed what and when they did it. Now to the demo. First cd to /d/learning/rcs_demo. There you will find a file called demo.txt This file has been placed under RCS control. If you type 'ed demo.txt' you'll find that it is read-only. If however, you check out demo.txt the file will be locked for your exclusive use. You, and only you, will then be able to edit the file. To checkout the file type 'rcsout demo.txt'. You will see something like: /d/learning/rcs_demo/RCS/demo.txt,v --> /d/learning/rcs_demo/demo.txt revision 1.1 (locked) done This indicates that RCS has locked the file for your use. Now edit the file and save your changes. After you have edited demo.txt and saved it, use 'rcsin demo.txt' to check the file back into RCS. rcsin will prompt you for a comment to explain what the changes you made were. It will then display something like: /d/learning/rcs_demo/RCS/demo.txt,v <-- /d/learning/rcs_demo/demo.txt new revision: 1.2; previous revision: 1.1 done Notice that the revision number has gone up by 1. This is because RCS keeps track of every previous version of the file. If you now more the file you will see something like: /* * $Locker: $ * $Id: demo.txt,v 1.2 1998/01/06 08:53:36 ceres Exp $ * * $Log: demo.txt,v $ * Revision 1.2 1998/01/06 08:53:36 ceres * A_demonstration_revision * * Revision 1.1 1998/01/06 08:51:02 ceres * Initial revision * */ These strings are maintained by RCS and show who has the file locked, what its name is and what edits have been made to it. Now we'll use rcsdiff to see the changes made between revisions of the demo.txt file. Use: rcsdiff -r1.1 -r1.2 demo.txt to see what I changed when I checked the file out, edited it and then returned it. Often it is useful to find out who, if anyone has a file locked. The command rcslog will do this for us. rcslog -h demo.txt will show the history of the file and who, if anyone, has it locked. It will look something like this: RCS file: /d/learning/rcs_demo/RCS/demo.txt,v Working file: /d/learning/rcs_demo/demo.txt head: 1.2 branch: locks: strict access list: symbolic names: keyword substitution: kv total revisions: 2 ============================================================================= rcslog can also be used to show just the files which are currently locked. Try rcslog -Lh demo.txt when you don't have demo.txt locked and again when you do. Don't forget to release your lock (using rcsin) when you're finished or noone else will be able to edit the file! To add your own files to RCS simply use rcscreate <filename> and bingo they'll be added to RCS. Ceres
