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.

NAME

       unget — undo a previous get of an SCCS file (DEVELOPMENT)

SYNOPSIS

       unget [−ns] [−r SID] file...

DESCRIPTION

       The unget utility shall reverse the effect of a get −e done prior to creating the intended
       new delta.

OPTIONS

       The unget utility shall conform to the Base Definitions volume  of  POSIX.1‐2008,  Section
       12.2, Utility Syntax Guidelines.

       The following options shall be supported:

       −r SID    Uniquely  identify  which  delta  is  no  longer intended. (This would have been
                 specified by get as the new delta.) The use of this option is necessary only  if
                 two or more outstanding get commands for editing on the same SCCS file were done
                 by the same person (login name).

       −s        Suppress the writing to standard output of the intended delta's SID.

       −n        Retain the file that was obtained by get, which would normally be  removed  from
                 the current directory.

OPERANDS

       The following operands shall be supported:

       file      A  pathname of an existing SCCS file or a directory. If file is a directory, the
                 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 s.)  and unreadable files shall be silently ignored.

                 If exactly one file operand appears, and it is '−', 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.

STDIN

       The  standard  input  shall be a text file used only when the file operand is specified as
       '−'.  Each line of the text file shall be interpreted as an SCCS pathname.

INPUT FILES

       Any SCCS files processed shall be files of an unspecified format.

ENVIRONMENT VARIABLES

       The following environment variables shall affect the execution of unget:

       LANG      Provide a default value for the internationalization variables that are unset or
                 null.   (See   the   Base  Definitions  volume  of  POSIX.1‐2008,  Section  8.2,
                 Internationalization  Variables  for  the  precedence  of   internationalization
                 variables used to determine the values of locale categories.)

       LC_ALL    If  set  to  a  non-empty  string  value,  override  the values of all the other
                 internationalization variables.

       LC_CTYPE  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).

       LC_MESSAGES
                 Determine the locale that should be used to affect the format  and  contents  of
                 diagnostic messages written to standard error.

       NLSPATH   Determine the location of message catalogs for the processing of LC_MESSAGES.

ASYNCHRONOUS EVENTS

       Default.

STDOUT

       The standard output shall consist of a line for each file, in the following format:

           "%s\n", <SID removed from file>

       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:

           "\n%s:\n", <pathname>

STDERR

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES

       Any SCCS files updated shall be files of an unspecified format.  During  processing  of  a
       file,  a locking z-file, as described in get, and a q-file (a working copy of the p-file),
       may be created and deleted. The p-file and g-file, as described in get, shall be deleted.

EXTENDED DESCRIPTION

       None.

EXIT STATUS

       The following exit values shall be returned:

        0    Successful completion.

       >0    An error occurred.

CONSEQUENCES OF ERRORS

       Default.

       The following sections are informative.

APPLICATION USAGE

       None.

EXAMPLES

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       delta, get, sact

       The Base Definitions volume of POSIX.1‐2008, Chapter  8,  Environment  Variables,  Section
       12.2, Utility Syntax Guidelines

COPYRIGHT

       Portions  of  this  text  are  reprinted  and  reproduced in electronic form from IEEE Std
       1003.1, 2013 Edition, Standard for Information Technology  --  Portable  Operating  System
       Interface  (POSIX),  The Open Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc  and  The  Open  Group.   (This  is
       POSIX.1-2008  with  the  2013  Technical  Corrigendum  1  applied.)  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.unix.org/online.html .

       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 .