Jump to content United States-English
HP.com Home Products and Services Support and Drivers Solutions How to Buy
» Contact HP
More options
HP.com home
HP-UX Reference > C


HP-UX 11i Version 3: February 2007

Technical documentation

» Feedback
Content starts here

 » Table of Contents

 » Index


comb — combine SCCS deltas


comb [-p SID] [-c list] [-o] [-s] file ...


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.


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.


The SCCSIDentification string (SID) of the oldest delta to be preserved. All older deltas are discarded in the reconstructed file.


A list of deltas to be preserved (see get(1) for the syntax of a list). All other deltas are discarded.


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.


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 Ч (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, comb preserves only leaf deltas and the minimal number of ancestors needed to preserve the tree.


International Code Set Support

Single- and multi-byte character code sets are supported.


Use sccshelp(1) for explanations.


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


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.



Temporary file


Temporary file

Printable version
Privacy statement Using this site means you accept its terms Feedback to webmaster
© 1983-2007 Hewlett-Packard Development Company, L.P.