'\"macro stdmacro
.if n .pH g1.delta @(#)delta	40.13 of 10/30/89
.\" Copyright 1989 AT&T
.nr X
.if \nX=0 .ds x} delta 1 "Source Code Control System Utilities" "\&"
.if \nX=1 .ds x} delta 1 "Source Code Control System Utilities"
.if \nX=2 .ds x} delta 1 "" "\&"
.if \nX=3 .ds x} delta "" "" "\&"
.TH \*(x}
.SH NAME
\f4delta\f1 \- make a delta (change) to an \s-1SCCS\s+1 file
.SH SYNOPSIS
\f4delta\f1 [\f4\-r\f2SID\f1] [\f4\-s\f1] [\f4\-n\f1]
[\f4\-g\f2list\f1] [\f4\-m\f1[\f2mrlist\f1]] [\f4\-y\f1[\f2comment\f1]]
[\f4\-p\f1]
.I files
.SH DESCRIPTION
\f4delta\fP
is used to permanently introduce into
the named \s-1SCCS\s+1 file changes that were made to the file retrieved by
\f4get \-e\fP
(called the
g-file
or generated file).
.PP
\f4delta\fP
makes a delta to each named \s-1SCCS\s+1 file.
If a directory is named,
\f4delta\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
(see the
.SM NOTES
section);
each line of the standard input is taken to be the name of an \s-1SCCS\s+1 file
to be processed.
.PP
\f4delta\fP
may issue prompts on the standard output depending on
certain keyletters specified and flags
[see
\f4admin\fP(1)]
that may be
present in the \s-1SCCS\s+1 file
(see
\f4\-m\f1
and
\f4\-y\f1
keyletters below).
.PP
Keyletter arguments
apply independently
to each named file.
.RS 5
.TP 15
\f4\-r\f2SID\f1
Uniquely
identifies which delta is to be made to the \s-1SCCS\s+1 file.
The use of this keyletter is necessary only if two or more
outstanding
\f4get\fPs
for editing
\f1(\f4get \-e\f1)
on the same \s-1SCCS\s+1 file were done by the same person
(login name).
The \s-1SID\s+1 value specified with the
\f4\-r\f1
keyletter can be either the \s-1SID\s+1 specified on the
\f4get\fP
command line or the \s-1SID\s+1 to be made as reported by the
\f4get\fP
command
[see
\f4get\fP(1)].
A diagnostic results if the specified \s-1SID\s+1 is ambiguous, or,
if necessary and omitted on the command line.
.TP 15
\f4\-s\f1
Suppresses
the issue, on the standard output, of the created delta's \s-1SID\s+1,
as well as the number of lines inserted, deleted and unchanged in the
\s-1SCCS\s+1 file.
.TP 15
\f4\-n\f1
Specifies retention of the edited
g-file
(normally removed at completion of delta processing).
.TP 15
\f4\-g\f2list\f1
Specify a \f2list\f1 [see
\f4get\fP(1)
for the definition of \f2list\f1]
of deltas that are to be
ignored
when the file is accessed at the change level (\s-1SID\s+1)
created by this delta.
.TP 15
\f4\-m\f1[mrlist]
If the \s-1SCCS\s+1 file has the
\f4v\f1
flag set
[see
\f4admin\fP(1)]
then a Modification Request (\s-1MR\s+1) number must be
supplied as the reason for creating the new delta.
If
\f4\-m\f1
is not used and the standard input is a terminal, the prompt
\f5MRs?\f1
is issued on the standard output before the standard input
is read; if the standard input is not a terminal, no prompt is issued.
The
\f5MRs?\f1
prompt always precedes the
\f5comments?\f1
prompt
(see
\f4\-y\f1
keyletter).
\s-1MR\s+1s
in a list are separated by blanks and/or tab characters.
An unescaped new-line character terminates the
.SM MR
list.
Note that if the
\f4v\f1
flag has a value
[see
\f4admin\fP(1)],
it is taken to be the name of a program (or shell procedure) that will validate
the correctness of the \s-1MR\s+1 numbers.
If a non-zero exit status is returned from the
.SM MR
number validation program,
\f4delta\fP
terminates.
(It is assumed that the
.SM MR
numbers were not all valid.)
.TP 15
\f4\-y\f1[comment]
Arbitrary text
used to describe the reason for making the delta.
A null string is considered a valid \f2comment\f1.
If
\f4\-y\f1
is not specified and the standard input is a terminal, the prompt
\f4comments?\f1
is issued on the standard output before the standard
input is read; if the standard input is not a terminal, no
prompt is issued.
An unescaped new-line character terminates the comment text.
.TP 15
\f4\-p\f1
Causes
\f4delta\fP
to print (on the standard output) the \s-1SCCS\s+1 file
differences before and after the delta is applied
in a
\f4diff\fP(1)
format.
.RE
.SH FILES
.PP
.PD 0
.TP "\w`\f4/usr/bin/bdiff\ \ \fP`u"
g-file
Existed
before the execution of
\f4delta\fP;
removed after completion of
\f4delta\fP.
.TP
p-file
Existed
before the execution of
\f4delta\fP;
may exist after completion of
\f4delta\fP.
.TP
q-file
Created during the execution of
\f4delta\fP;
removed after completion of
\f4delta\fP.
.TP
x-file
Created during the execution of
\f4delta\fP;
renamed to \s-1SCCS\s+1 file after completion of
\f4delta\fP.
.TP
z-file
Created during the execution of
\f4delta\fP;
removed during the execution of
\f4delta\fP.
.TP
d-file
Created during the execution of
\f4delta\fP;
removed after completion of
\f4delta\fP.
.TP
\f4bdiff\fP
Program to compute differences
between the ``gotten'' file and the
g-file.
.PD
.SH "SEE ALSO"
\f4admin\fP(1),
\f4cdc\fP(1),
\f4get\fP(1),
\f4help\fP(1),
\f4prs\fP(1),
\f4rmdel\fP(1),
\f4sccsfile\fP(4).
.br
\f4bdiff\fP(1)
in the \f2User's Reference Manual\f1.
.SH DIAGNOSTICS
Use
\f4help\fP(1)
for explanations.
.SH NOTES
A
\f4get\fP
of many \s-1SCCS\s+1 files,
followed by a
\f4delta\fP
of those files, should be avoided when the
\f4get\fP
generates a large amount of data.
Instead,
multiple
\f4get\f1/\f4delta\^\f1
sequences should be used.
.PP
If the standard input
(\f4\-\f1)
is specified on the
\f4delta\fP
command line,
the
\f4\-m\f1
(if necessary)
and
\f4\-y\f1
keyletters
must
also be present.
Omission of these keyletters causes an error.
.PP
Comments are limited to text strings of at most 1024 characters.
Line lengths greater than 1000 characters cause undefined results.
