Source code control system (SCCS)

Formatting

SCCS files are composed of lines of ASCII text arranged in six parts as follows:

Checksum: Line containing the logical sum of all the characters of the file (not including the checksum itself).
Delta table: Information about each delta, such as type, SID, date and time of creation, and commentary.
User names: List of login names and/or group IDs of users who are allowed to modify the file by adding or removing deltas.
Flags: Indicators that control certain actions of SCCS commands.
Descriptive text: Usually a summary of the contents and purpose of the file.
Body: Text administered by SCCS, intermixed with internal SCCS control lines.

Details on these file sections can be found in sccsfile(FP). The checksum is discussed next under ``Auditing''.

Since SCCS files are ASCII files, they can be processed by non-SCCS commands like ed(C), grep(C), and cat(C). This is convenient when an SCCS file must be modified manually (such as when a delta's time and date were recorded incorrectly because the system clock was set incorrectly), or when a user wants simply to look at the file.

NOTE: Be careful when modifying SCCS files with non-SCCS commands.