comb(1) General Commands Manual comb(1)
NAME
comb - combine SCCS deltas
SYNOPSIS
SID] list] file ...
DESCRIPTION
The command generates a shell procedure (see sh(1)) which, when run, reconstructs the given SCCS files. The reconstructed files are usu-
ally smaller than the original files. Arguments can be specified in any order, but all options apply to all named SCCS files. If a direc-
tory is named, 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 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
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.
The SCCS IDentification string (SID) of the oldest delta to be preserved. All older deltas are discarded in the recon-
structed file.
A list of deltas to be preserved (see get(1) for the syntax of a list). All other deltas are discarded.
For each generated, this option causes the reconstructed file to be accessed at the release of the delta to be created, other-
wise the reconstructed file would be accessed at the most recent ancestor. Use of the option can decrease the size
of the reconstructed SCCS file. It can also alter the shape of the delta tree of the original file.
This option causes
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
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, preserves only leaf deltas and the minimal number of ancestors needed to preserve the tree.
EXTERNAL INFLUENCES
International Code Set Support
Single- and multi-byte character code sets are supported.
DIAGNOSTICS
Use sccshelp(1) for explanations.
EXAMPLES
The command:
creates a shell script named which if executed, creates a new using only the deltas from the old The script overwrites the old thus, it
might be wise to copy the original elsewhere. Here is an example of typical technique:
WARNINGS
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
Temporary file
Temporary file
SEE ALSO
admin(1), delta(1), get(1), sccshelp(1), prs(1), sh(1), sccsfile(4).
comb(1)