comb - Combines Source Code Control System (SCCS) deltas
comb [-clist] [-os] [-pSID] file...
The comb command writes to standard output a shell procedure for combining
the specified deltas (SIDs) of an SCCS file and creating a new version of
the file with fewer deltas.
Each option or group of options applies independently to each named file.
Specifies a list of deltas (SIDs) that the shell procedure will
preserve (see get -ilist). The procedure will combine all other deltas.
-o Accesses the reconstructed file at the release of the delta to be
created for each get -e generated; otherwise, accesses the recon-
structed file at the most recent ancestor. Using the -o option may
decrease the size of the reconstructed SCCS file. It may also alter
the shape of the delta tree of the original file.
Specifies the SID of the oldest delta for the resulting procedure to
preserve. All older deltas are combined in the reconstructed file.
-s Causes comb to generate a shell procedure that, instead of combining
the deltas, produces a report for each file, which lists the file name,
size (in blocks) after combining, original size (also in blocks), and
percentage change computed by the following formula:
100 * (original - combined) / original
Run comb using this option before actually combining SCCS deltas in
order to judge how much space will actually be saved by the combining
By piping the output of the comb command to a shell, or redirecting the
output to a file and running that file as a shell procedure, you can reduce
the size of your SCCS file. You can first see how much the file will be
reduced by running the comb command with the -s option.
If you specify a directory in place of file, the comb command performs the
requested actions on all SCCS files (that is, those with file names with
the s. prefix). If you specify a - (dash) in place of file, the comb com-
mand reads standard input and interprets each line as the name of an SCCS
file. The comb command continues to take input until it reads End-of-File.
If you do not specify any options, the comb command preserves only leaf
deltas and the minimal number of ancestors needed to preserve the tree (see
the delta command).
The comb command may rearrange the shape of the tree deltas.
The comb command may not save any space; in fact, it is possible for the
reconstructed file to actually be larger than the original.
1. To generate a report on how much space will be saved by combing all
deltas older than SID 1.4 for SCCS file s.test.c, enter:
comb -p1.4 -s s.test.c | sh
2. To actually combine the deltas, enter:
comb -p1.4 s.test.c | sh
Commands: admin(1), cdc(1), delta(1), get(1), prs(1), rmdel(1), sact(1),
sccs(1), sccsdiff(1), sccshelp(1), unget(1), val(1), what(1)
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