comb(1)

comb(1)

NAME

comb - combine SCCS deltas

SYNOPSIS

comb [-pSID ] [-clist] [-o] [-s] ®le ...

DESCRIPTION

The comb command generates a shell procedure (see sh(1)) which, when run, reconstructs the given SCCS ®les. The reconstructed ®les are usually smaller than the original ®les. Arguments can be speci®ed in any order, but all options apply to all named SCCS ®les. If a directory is named, comb behaves as though each ®le in the directory were speci®ed as a named ®le, except that non-SCCS®les (last component of the path name does not begin with s.) and unreadable ®les 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 ®le to be processed; non-SCCS®les and unreadable ®les are silently ignored. The generated shell procedure is written on the standard output.

Options

comb recognizes the following options. Each is explained as if only one named ®le is to be processed, but the effects of any option apply independently to each named ®le.

-pSID

The SCCS IDenti®cation string (SID) of the oldest delta to be preserved. All older del-

 

tas are discarded in the reconstructed ®le.

-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 -egenerated, this option causes the reconstructed ®le to be accessed

 

at the release of the delta to be created, otherwise the reconstructed ®le would be

 

accessed at the most recent ancestor. Use of the -ooption can decrease the size of

 

the reconstructed SCCS ®le. It can also alter the shape of the delta tree of the original

 

®le.

-s

This option causes comb to generate a shell procedure which, when run, produces a

 

report giving, for each ®le: the ®le name, size (in blocks) after combining, original size

 

(also in blocks), and percentage change computed by:

 

100 × (original − combined) / original

 

It is recommended that this option be used before any SCCS ®les are actually com-

 

bined to determine exactly how much space is saved by the combining process.

If no options are speci®ed, comb 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:

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

comb may rearrange the shape of the tree of deltas. Combining ®les may or may not save space; in fact, it is possible for the reconstructed ®le to actually be larger than the original.

HP-UX Release 11i: December 2000

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Section 1−103

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