'\"macro stdmacro
.if n .pH g1.comb @(#)comb	40.9 of 10/10/89
.\" Copyright 1989 AT&T
.tr ~
.nr X
.if \nX=0 .ds x} comb 1 "Source Code Control System Utilities" "\&"
.if \nX=1 .ds x} comb 1 "Source Code Control System Utilities"
.if \nX=2 .ds x} comb 1 "" "\&"
.if \nX=3 .ds x} comb "" "" "\&"
.TH \*(x}
.SH NAME
\f4comb\f1 \- combine \s-1SCCS\s+1 deltas
.SH SYNOPSIS
\f4comb [\-o] [\-s] [\-p\f2\s-1SID\s0\f4] [\-c\f2list\f4] \f2files  \f1
.SH DESCRIPTION
\f4comb\fP
generates a shell procedure [see
\f4sh\fP(1)]
that, when run, reconstructs the given \s-1SCCS\s+1 files.
The reconstructed files are typically smaller than the original files.
The arguments may be specified in any order,
but all keyletter arguments apply to all named \s-1SCCS\s+1 files.
If a directory is named,
\f4comb\fP
behaves as though each file in the directory were
specified as a named file,
except that non-\s-1SCCS\s+1 files
(last component of the path name does not begin with \f4s.\f1)
and unreadable files are silently ignored.
If a name of \f4\-\f1 is given, the standard input is read;
each line of the input is taken to be the name of an \s-1SCCS\s+1 file
to be processed;
non-\s-1SCCS\s+1 files and unreadable files are silently ignored.
The generated shell procedure is written on the standard output.
.PP
The keyletter
arguments are as follows.
Each argument is explained as if only one named file
is to be processed, but the effects of any keyletter argument
apply independently to each named file.
.TP
\f4\-o\fP
For each
\f4get \-e\f1,
this argument 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
\f4\-o\f1
keyletter may decrease the size of the reconstructed \s-1SCCS\s+1 file.
It may also alter the shape of the delta tree of the original file.
.TP
\f4\-s\fP
This
argument causes
\f4comb\fP
to generate a shell procedure that, when run,
produces a report that gives
for each file:
the file name, size (in blocks) after combining,
original size (also in blocks), and
percentage change
computed by:
.IP
	\%100~\f4\(**\f1~(\f2original\f1~\-~\f2combined\f1)~/~\f2original\f1
.IP
It is recommended that before any \s-1SCCS\s+1 files are actually combined,
one should use this option to determine exactly how much space
is saved by the combining process.
.TP
\f4\-p\f2\s-1SID\s+1\f1
The
.SM SCCS
identification string (\s-1SID\s+1) of the oldest delta to be preserved.
All older deltas are discarded in the reconstructed file.
.TP
\f4\-c\f2list\f1
A
.I list\^
of deltas to be preserved.
All other deltas are discarded.
See
\f4get\fP(1)
for the syntax of a \f2list\f1.
.PP
If no keyletter arguments are specified,
\f4comb\fP
preserves only leaf deltas and the minimal number of ancestors
needed to preserve the tree.
.SH FILES
.PD 0
.TP 14
\f4s.COMB\f1
the reconstructed \s-1SCCS\s+1 file
.TP 14
\f4comb?????\fP
temporary file
.PD
.SH "SEE ALSO"
\f4admin\fP(1),
\f4delta\fP(1),
\f4get\fP(1),
\f4help\fP(1),
\f4prs\fP(1),
\f4sccsfile\fP(4).
.sp .2
\f4sh\fP(1) in the \f2User's Reference Manual\f1.
.SH DIAGNOSTICS
Use
\f4help\fP(1)
for explanations.
.SH NOTES
\f4comb\fP
may rearrange the shape of the tree of deltas.
.P
\f4comb\fP may not save any space;
in fact, it is possible for the reconstructed file to
be larger than the original.
.tr ~~
