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 .

IEEE/The Open Group                                   2013                                         UNGET(1POSIX)