Checking in a New Version: sccs delta

Having first checked out your file and completed your edits, you can check in the changes using sccs delta.

Checking a file in is also referred to as making a delta. Before checking in your updates, SCCS prompts you for comments. These typically include a brief summary of your changes.

$ sccs delta program.c
comments?

Comments should be meaningful, since you may return to the file one day.

You can extend the comment to an additional input line by preceding the NEWLINE with a backslash:

$ sccs delta program.c
comments? corrected typo in widget(), \ 
null pointer in n_crunch()
1.2
5 inserted 
3 deleted
84 unchanged

SCCS responds by noting the SID of the new version, and the numbers of lines inserted, deleted and unchanged. Changed lines count as lines deleted and inserted. SCCS removes the working copy. You can retrieve a read-only version using sccs get.

Think ahead before checking in a version. Creating deltas after each minor edit can become excessive. On the other hand, leaving files checked out for so long that you forget about them can inconvenience others.

It is important to check in all changed files before compiling or installing a module for general use. A good technique is to:

• Edit the files you need.

• Make all necessary changes and tests.

• Compile and debug the files until you are satisfied.

• Check them in, retrieve read-only copies with get.

• Recompile the module.