17. The SCCS Utility

Contents:
Overview of Commands
Basic Operation
Identification Keywords
Data Keywords
Alphabetical Summary of SCCS Commands
sccs and Pseudo-commands

This section presents the following topics:

Overview of commands
Basic operation
Identification keywords
Data keywords
Alphabetical summary of commands
sccs and pseudo-commands

Note: SCCS users who are more familiar with RCS may benefit from the "Conversion Guide for SCCS Users" in Section 18. This lists SCCS commands and their RCS equivalents.

The Source Code Control System (SCCS) lets you keep track of each revision of a document, avoiding the confusion that often arises from having several versions of one file on line. SCCS is particularly useful when programs are enhanced but the original version is still needed.

All changes to a file are stored in a file named s. file , which is called an SCCS file. Each time a file is "entered" into SCCS, SCCS notes which lines have been changed or deleted since the most recent version. From that information, SCCS can regenerate the file on demand. Each set of changes depends on all previous sets of changes.

Each set of changes is called a delta and is assigned an S CCS id entification string (sid ). The sid consists of either two components, release and level numbers (in the form a . b ), or of four components: the release, level, branch, and sequence numbers (in the form a . b . c . d ). The branches and sequences are for situations when two on-running versions of the same file are recorded in SCCS. For example, delta 3.2.1.1 refers to release 3, level 2, branch 1, sequence 1.

17.1 Overview of Commands

SCCS commands fall into several categories:

17.1.1 Basic Set Up and Editing

admin: Create new SCCS files and change their parameters.
get: Retrieve versions of SCCS files.
delta: Create a new version of an SCCS file (i.e., append a new delta ).
unget: Cancel a get operation; don't create a new delta.

17.1.2 Fixing Deltas

cdc: Change the comment associated with a delta.
comb: Combine consecutive deltas into a single delta.
rmdel: Remove an accidental delta from an SCCS file.

17.1.3 Information

help: Print a command synopsis or clarify diagnostic messages.
prs: Print portions of SCCS files in a specified format.
sact: Show editing activity on SCCS files.
what: Search for all occurrences of the pattern get substitutes for %Z% , and print out the following text.

17.1.4 Comparing Files

sccsdiff: Show the differences between any two SCCS files.
val: Validate an SCCS file.