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.