CSE 401: Compilers

Help / Groups and RCS

Group Files

RCS Access control

1. Create a directory called RCS in your group's project directory, and a symbolic link to it from your working directory: cd /projects/instr/cse401/98au/401z mkdir RCS cd ~/myfavoritecourse/pl0 ln -s /projects/instr/cse401/98au/401z/RCS RCS
2. Get the base project files: cp /cse/courses/cse401/CurrentQtr/pl0_base/* ~/myfavoritecourse/pl0
3. Register all the files with RCS. cd ~/myfavoritecourse/pl0 foreach foo (*) ci -u -t-$foo $foo end You only need to do this once for each file. If you create a new file you should check it via the ci line above or clicking on Tools->Version Control->Register in emacs.

4. The procedure above will leave you with a read-only copy of each file. To edit a file, say scanner.c, you need to "check out" a "locked" copy of it, then check it back in when you're finished. co -l scanner.c emacs scanner.c <...edit & test to your heart's content...> ci -u scanner.c Alternatively, it's easy to check files in and out using emacs; simply visit the file and then hit C-x C-q (control-x control-q). (Use the menus if you forget). Note that if you haven't registered the file, the emacs mode-line won't say RCS and C-x C-q will simply toggle the read-only status of the file.

   If you try to check out a file that someone's already using, RCS and/or emacs will let you know who. Otherwise, it will give you the lock to the file and nobody else will be able to check out that file until you check it back in.

5. RCS itself will not automatically give your partners a file that you check back in. This is a feature; they can choose when they want to synchronize their files with the master versions. (For example, if they know that you've checked in a buggy module that can't yet compile, but they still want to keep working on their own part which isn't dependent on it.)

   If you want to make sure that all of your files are the most current versions, you can run:

   co RCS/* Alternatively, the following may work on some systems (the Indy's?): rsync -v
6. Some hints:
   • The first time you edit a file, I recommend adding the line: // $Header$ at the top of the file; on subsequent checkouts, this line will be replaced with RCS header info --- file name, version number, time stamp, etc.

   • Try not to check-in a module that won't compile. Your partners will be irked if they synchronize their files and find they can't work on their own modules until you fix yours. (If it helps, you can check out a previous version if this happens to you; see man co.)

   • To read about emacs's interface to RCS, type this within emacs: C-h i g (emacs)Version Control You can click on the hypertext links with the middle-button.

   • Split separate modules into different files so that your partners can work on other routines simultaneously.

   • Make Version Snapshots often. That makes RCS remember not just the state one file is in, but the state that all of the files are in. Emacs allows you to take a snapshot by typing either M-x vc-create-snapshot, or C-x v s.

   • To read about RCS, take a look at man rcsintro, rcs, ci, co, rsync, rlog, and rcsdiff.