delta.1p (10044B)
- '\" et
- .TH DELTA "1P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
- .\"
- .SH PROLOG
- This manual page is part of the POSIX Programmer's Manual.
- The Linux implementation of this interface may differ (consult
- the corresponding Linux manual page for details of Linux behavior),
- or the interface may not be implemented on Linux.
- .\"
- .SH NAME
- delta
- \(em make a delta (change) to an SCCS file (\fBDEVELOPMENT\fP)
- .SH SYNOPSIS
- .LP
- .nf
- delta \fB[\fR-nps\fB] [\fR-g \fIlist\fB] [\fR-m \fImrlist\fB] [\fR-r \fISID\fB] [\fR-y\fB[\fIcomment\fB]] \fIfile\fR...
- .fi
- .SH DESCRIPTION
- The
- .IR delta
- utility shall be used to permanently introduce into the named SCCS
- files changes that were made to the files retrieved by
- .IR get
- (called the
- .IR g-files ,
- or generated files).
- .SH OPTIONS
- The
- .IR delta
- utility shall conform to the Base Definitions volume of POSIX.1\(hy2017,
- .IR "Section 12.2" ", " "Utility Syntax Guidelines",
- except that the
- .BR \-y
- option has an optional option-argument. This optional option-argument
- shall not be presented as a separate argument.
- .P
- The following options shall be supported:
- .IP "\fB\-r\ \fISID\fR" 10
- Uniquely identify which delta is to be made to the SCCS file. The use
- of this option shall be necessary only if two or more outstanding
- .IR get
- commands for editing (\c
- .IR get
- .BR \-e )
- on the same SCCS file were done by the same person (login name). The
- SID value specified with the
- .BR \-r
- option can be either the SID specified on the
- .IR get
- command line or the SID to be made as reported by the
- .IR get
- utility; see
- .IR "\fIget\fR\^".
- .IP "\fB\-s\fP" 10
- Suppress the report to standard output of the activity associated with
- each
- .IR file .
- See the STDOUT section.
- .IP "\fB\-n\fP" 10
- Specify retention of the edited
- .IR g-file
- (normally removed at completion of delta processing).
- .IP "\fB\-g\ \fIlist\fR" 10
- Specify a
- .IR list
- (see
- .IR "\fIget\fR\^"
- for the definition of
- .IR list )
- of deltas that shall be ignored when the file is accessed at the
- change level (SID) created by this delta.
- .IP "\fB\-m\ \fImrlist\fR" 10
- Specify a modification request (MR) number that the application shall
- supply as the reason for creating the new delta. This shall be used if
- the SCCS file has the
- .BR v
- flag set; see
- .IR "\fIadmin\fR\^".
- .RS 10
- .P
- If
- .BR \-m
- is not used and
- .BR '\-'
- is not specified as a file argument, and the standard input is a
- terminal, the prompt described in the STDOUT section shall be written
- to standard output before the standard input is read; if the standard
- input is not a terminal, no prompt shall be issued.
- .P
- MRs in a list shall be separated by
- <blank>
- characters or escaped
- <newline>
- characters. An unescaped
- <newline>
- shall terminate the MR list. The escape character is
- <backslash>.
- .P
- If the
- .BR v
- flag has a value, it shall be taken to be the name of a program which
- validates the correctness of the MR numbers. If a non-zero exit status
- is returned from the MR number validation program, the
- .IR delta
- utility shall terminate. (It is assumed that the MR numbers were not
- all valid.)
- .RE
- .IP "\fB\-y\fB[\fIcomment\fB]\fR" 10
- Describe the reason for making the delta. The
- .IR comment
- shall be an arbitrary group of lines that would meet the definition of
- a text file. Implementations shall support
- .IR comment s
- from zero to 512 bytes and may support longer values. A null string
- (specified as either
- .BR \-y ,
- .BR \-y \c
- .BR \(dq\^\(dq ,
- or in response to a prompt for a comment) shall be considered a valid
- .IR comment .
- .RS 10
- .P
- If
- .BR \-y
- is not specified and
- .BR '\-'
- is not specified as a file argument, and the standard input is a
- terminal, the prompt described in the STDOUT section shall be written
- to standard output before the standard input is read; if the standard
- input is not a terminal, no prompt shall be issued. An unescaped
- <newline>
- shall terminate the comment text. The escape character is
- <backslash>.
- .P
- The
- .BR \-y
- option shall be required if the
- .IR file
- operand is specified as
- .BR '\-' .
- .RE
- .IP "\fB\-p\fP" 10
- Write (to standard output) the SCCS file differences before and after
- the delta is applied in
- .IR diff
- format; see
- .IR "\fIdiff\fR\^".
- .SH OPERANDS
- The following operand shall be supported:
- .IP "\fIfile\fR" 10
- A pathname of an existing SCCS file or a directory. If
- .IR file
- is a directory, the
- .IR delta
- utility shall behave as though each file in the directory were
- specified as a named file, except that non-SCCS files (last component
- of the pathname does not begin with
- .BR s. )
- and unreadable files shall be silently ignored.
- .RS 10
- .P
- If exactly one
- .IR file
- operand appears, and it is
- .BR '\-' ,
- the standard input shall be read; each line of the standard input shall
- be taken to be the name of an SCCS file to be processed. Non-SCCS files
- and unreadable files shall be silently ignored.
- .RE
- .SH STDIN
- The standard input shall be a text file used only in the following
- cases:
- .IP " *" 4
- To read an
- .IR mrlist
- or a
- .IR comment
- (see the
- .BR \-m
- and
- .BR \-y
- options).
- .IP " *" 4
- A
- .IR file
- operand shall be specified as
- .BR '\-' .
- In this case, the
- .BR \-y
- option must be used to specify the comment, and if the SCCS file has
- the
- .BR v
- flag set, the
- .BR \-m
- option must also be used to specify the MR list.
- .SH "INPUT FILES"
- Input files shall be text files whose data is to be included in the
- SCCS files. If the first character of any line of an input file is
- <SOH>
- in the POSIX locale, the results are unspecified. If this file contains
- more than 99\|999 lines, the number of lines recorded in the header for
- this file shall be 99\|999 for this delta.
- .SH "ENVIRONMENT VARIABLES"
- The following environment variables shall affect the execution of
- .IR delta :
- .IP "\fILANG\fP" 10
- Provide a default value for the internationalization variables that are
- unset or null. (See the Base Definitions volume of POSIX.1\(hy2017,
- .IR "Section 8.2" ", " "Internationalization Variables"
- for the precedence of internationalization variables used to determine
- the values of locale categories.)
- .IP "\fILC_ALL\fP" 10
- If set to a non-empty string value, override the values of all the
- other internationalization variables.
- .IP "\fILC_CTYPE\fP" 10
- Determine the locale for the interpretation of sequences of bytes of
- text data as characters (for example, single-byte as opposed to
- multi-byte characters in arguments and input files).
- .IP "\fILC_MESSAGES\fP" 10
- .br
- Determine the locale that should be used to affect the format and
- contents of diagnostic messages written to standard error, and
- informative messages written to standard output.
- .IP "\fINLSPATH\fP" 10
- Determine the location of message catalogs for the processing of
- .IR LC_MESSAGES .
- .IP "\fITZ\fP" 10
- Determine the timezone in which the time and date are written in the
- SCCS file. If the
- .IR TZ
- variable is unset or NULL, an unspecified system default timezone is
- used.
- .SH "ASYNCHRONOUS EVENTS"
- If SIGINT is caught, temporary files shall be cleaned up and
- .IR delta
- shall exit with a non-zero exit code. The standard action shall
- be taken for all other signals; see
- .IR "Section 1.4" ", " "Utility Description Defaults".
- .SH STDOUT
- The standard output shall be used only for the following messages in
- the POSIX locale:
- .IP " *" 4
- Prompts (see the
- .BR \-m
- and
- .BR \-y
- options) in the following formats:
- .RS 4
- .sp
- .RS 4
- .nf
- "MRs? "
- .P
- "comments? "
- .fi
- .P
- .RE
- .P
- The MR prompt, if written, shall always precede the comments prompt.
- .RE
- .IP " *" 4
- A report of each file's activities (unless the
- .BR \-s
- option is specified) in the following format:
- .RS 4
- .sp
- .RS 4
- .nf
- "%s\en%d inserted\en%d deleted\en%d unchanged\en", <\fINew SID\fR>,
- <\fInumber of lines inserted\fR>, <\fInumber of lines deleted\fR>,
- <\fInumber of lines unchanged\fR>
- .fi
- .P
- .RE
- .RE
- .SH STDERR
- The standard error shall be used only for diagnostic messages.
- .SH "OUTPUT FILES"
- Any SCCS files updated shall be files of an unspecified format.
- .SH "EXTENDED DESCRIPTION"
- .SS "System Date and Time"
- .P
- When a delta is added to an SCCS file, the system date and time shall
- be recorded for the new delta. If a
- .IR get
- is performed using an SCCS file with a date recorded apparently in the
- future, the behavior is unspecified.
- .SH "EXIT STATUS"
- The following exit values shall be returned:
- .IP "\00" 6
- Successful completion.
- .IP >0 6
- An error occurred.
- .SH "CONSEQUENCES OF ERRORS"
- Default.
- .LP
- .IR "The following sections are informative."
- .SH "APPLICATION USAGE"
- Problems can arise if the system date and time have been modified (for
- example, put forward and then back again, or unsynchronized clocks
- across a network) and can also arise when different values of the
- .IR TZ
- environment variable are used.
- .P
- Problems of a similar nature can also arise for the operation of the
- .IR get
- utility, which records the date and time in the file body.
- .SH EXAMPLES
- None.
- .SH RATIONALE
- None.
- .SH "FUTURE DIRECTIONS"
- None.
- .SH "SEE ALSO"
- .IR "Section 1.4" ", " "Utility Description Defaults",
- .IR "\fIadmin\fR\^",
- .IR "\fIdiff\fR\^",
- .IR "\fIget\fR\^",
- .IR "\fIprs\fR\^",
- .IR "\fIrmdel\fR\^"
- .P
- The Base Definitions volume of POSIX.1\(hy2017,
- .IR "Chapter 8" ", " "Environment Variables",
- .IR "Section 12.2" ", " "Utility Syntax Guidelines"
- .\"
- .SH COPYRIGHT
- Portions of this text are reprinted and reproduced in electronic form
- from IEEE Std 1003.1-2017, Standard for Information Technology
- -- Portable Operating System Interface (POSIX), The Open Group Base
- Specifications Issue 7, 2018 Edition,
- Copyright (C) 2018 by the Institute of
- Electrical and Electronics Engineers, Inc and The Open Group.
- In the event of any discrepancy between this version and the original IEEE and
- The Open Group Standard, the original IEEE and The Open Group Standard
- is the referee document. The original Standard can be obtained online at
- http://www.opengroup.org/unix/online.html .
- .PP
- Any typographical or formatting errors that appear
- in this page are most likely
- to have been introduced during the conversion of the source files to
- man page format. To report such errors, see
- https://www.kernel.org/doc/man-pages/reporting_bugs.html .