'\" et
.TH UNGET "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
unget
\(em undo a previous get of an SCCS file (\fBDEVELOPMENT\fP)
.SH SYNOPSIS
.LP
.nf
unget \fB[\fR-ns\fB] [\fR-r \fISID\fB] \fIfile\fR...
.fi
.SH DESCRIPTION
The
.IR unget
utility shall reverse the effect of a
.IR get
.BR \-e
done prior to creating the intended new delta.
.SH OPTIONS
The
.IR unget
utility shall conform to the Base Definitions volume of POSIX.1\(hy2017,
.IR "Section 12.2" ", " "Utility Syntax Guidelines".
.P
The following options shall be supported:
.IP "\fB\-r\ \fISID\fR" 10
Uniquely identify which delta is no longer intended. (This would have
been specified by
.IR get
as the new delta.) The use of this option is necessary only if two or
more outstanding
.IR get
commands for editing on the same SCCS file were done by the same person
(login name).
.IP "\fB\-s\fP" 10
Suppress the writing to standard output of the intended delta's SID.
.IP "\fB\-n\fP" 10
Retain the file that was obtained by
.IR get ,
which would normally be removed from the current directory.
.SH OPERANDS
The following operands 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 unget
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 when the
.IR file
operand is specified as
.BR '\-' .
Each line of the text file shall be interpreted as an SCCS pathname.
.SH "INPUT FILES"
Any SCCS files processed shall be files of an unspecified format.
.SH "ENVIRONMENT VARIABLES"
The following environment variables shall affect the execution of
.IR unget :
.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.
.IP "\fINLSPATH\fP" 10
Determine the location of message catalogs for the processing of
.IR LC_MESSAGES .
.SH "ASYNCHRONOUS EVENTS"
Default.
.SH STDOUT
The standard output shall consist of a line for each file, in the
following format:
.sp
.RS 4
.nf

"%s\en", <\fISID removed from file\fR>
.fi
.P
.RE
.P
If there is more than one named file or if a directory or standard
input is named, each pathname shall be written before each of the
preceding lines:
.sp
.RS 4
.nf

"\en%s:\en", <\fIpathname\fR>
.fi
.P
.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.
During processing of a
.IR file ,
a locking
.IR z-file ,
as described in
.IR get ,
and a
.IR q-file
(a working copy of the
.IR p-file ),
may be created and deleted. The
.IR p-file
and
.IR g-file ,
as described in
.IR get ,
shall be deleted.
.SH "EXTENDED DESCRIPTION"
None.
.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"
None.
.SH EXAMPLES
None.
.SH RATIONALE
None.
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
.IR "\fIdelta\fR\^",
.IR "\fIget\fR\^",
.IR "\fIsact\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 .