comb(1) comb(1)
NAME [Toc] [Back]
comb - combine SCCS deltas
SYNOPSIS [Toc] [Back]
comb [-pSID] [-clist] [-o] [-s] file ...
DESCRIPTION [Toc] [Back]
The comb command generates a shell procedure (see sh(1)) which, when
run, reconstructs the given SCCS files. The reconstructed files are
usually smaller than the original files. Arguments can be specified
in any order, but all options apply to all named SCCS files. If a
directory is named, comb behaves as though each file in the directory
were specified as a named file, except that non-SCCS files (last
component of the path name does not begin with s.) and unreadable
files are silently ignored. If a name of - is given, the standard
input is read; each line of the standard input is taken to be the name
of an SCCS file to be processed; non-SCCS files and unreadable files
are silently ignored. The generated shell procedure is written on the
standard output.
Options [Toc] [Back]
comb recognizes the following options. Each is explained as if only
one named file is to be processed, but the effects of any option apply
independently to each named file.
-pSID The SCCS IDentification string (SID) of the oldest
delta to be preserved. All older deltas are
discarded in the reconstructed file.
-clist A list of deltas to be preserved (see get(1) for
the syntax of a list). All other deltas are
discarded.
-o For each get -e generated, this option causes the
reconstructed file to be accessed at the release
of the delta to be created, otherwise the
reconstructed file would be accessed at the most
recent ancestor. Use of the -o option can
decrease the size of the reconstructed SCCS file.
It can also alter the shape of the delta tree of
the original file.
-s This option causes comb to generate a shell
procedure which, when run, produces a report
giving, for each file: the file name, size (in
blocks) after combining, original size (also in
blocks), and percentage change computed by:
100 x (original - combined) / original
Hewlett-Packard Company - 1 - HP-UX 11i Version 2: August 2003
comb(1) comb(1)
It is recommended that this option be used before
any SCCS files are actually combined to determine
exactly how much space is saved by the combining
process.
If no options are specified, comb preserves only leaf deltas and the
minimal number of ancestors needed to preserve the tree.
EXTERNAL INFLUENCES [Toc] [Back]
International Code Set Support
Single- and multi-byte character code sets are supported.
DIAGNOSTICS [Toc] [Back]
Use sccshelp(1) for explanations.
EXAMPLES [Toc] [Back]
The command:
comb -c1.1,1.3,1.6 s.document > save_file
creates a shell script named save_file, which if executed, creates a
new s.document using only the deltas 1.1, 1.3,and 1.6 from the old
s.document. The script overwrites the old s.document; thus, it might
be wise to copy the original elsewhere. Here is an example of typical
technique:
cp s.document s.save
comb -c1.1,1.3,1.6 s.document > save_file
sh save_file
WARNINGS [Toc] [Back]
comb may rearrange the shape of the tree of deltas. Combining files
may or may not save space; in fact, it is possible for the
reconstructed file to actually be larger than the original.
FILES [Toc] [Back]
s.COMB????? Temporary file
comb????? Temporary file
SEE ALSO [Toc] [Back]
admin(1), delta(1), get(1), sccshelp(1), prs(1), sh(1), sccsfile(4).
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