As shown in the previous example, get
retrieves the latest version of the file s.lang.
This is accomplished by starting with the original version and
successively applying the changes (deltas) in order until all
have been applied.
If the get command is issued now, it retrieves
version 1.2 of the file s.lang. Any of the
following invocations of get produces the same
get -r1 s.lang
get -r1.2 s.lang
The numbers following the -r are SIDs. When the level number of the SID (get -r s.lang) is omitted, the default is the highest level number existing within that specific release. The second command (get -r1 s.lang) requests the retrieval of the latest version of release 1. The third command specifically requests the retrieval of a particular version, release 1 level 2.
Whenever a significant change is made to a file, the usual identification
method is to increase the release number (the first number of the SID).
Because normal automatic numbering of deltas proceeds by incrementing
the level number, the user must explicitly instruct SCCS to increment
the release number. This is accomplished as follows:
get -e -r2 s.lang
Release 2 does not exist, so get retrieves the latest version before release 2. The get command also interprets this as a request to change the release number of the new delta to 2, thereby naming it 2.1 rather than 1.3. The output that follows indicates that version 1.2 has been retrieved, and 2.1 is the new delta version that will be created.
1.2 new delta 2.1 7 linesIf the file is now edited (for example, by deleting COBOL from the list of languages) and delta is executed:
comments?deleted COBOL from the list of languages
Then the delta's output is:
2.1 0 inserted 1 deleted 6 unchangedDeltas can now be created in release 2 (deltas 2.2, 2.3, and so on), or another new release can be created in a similar manner.