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COLON(1P)                  POSIX Programmer's Manual                 COLON(1P)

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
       colon - null utility
SYNOPSIS
       : [argument ...]
DESCRIPTION
       This utility shall only expand command arguments. It  is  used  when  a
       command is needed, as in the then condition of an if command, but noth-
       ing is to be done by the command.
OPTIONS
       None.
OPERANDS
       See the DESCRIPTION.
STDIN
       Not used.
INPUT FILES
       None.
ENVIRONMENT VARIABLES
       None.
ASYNCHRONOUS EVENTS
       Default.
STDOUT
       Not used.
STDERR
       The standard error shall be used only for diagnostic messages.
OUTPUT FILES
       None.
EXTENDED DESCRIPTION
       None.
EXIT STATUS
       Zero.
CONSEQUENCES OF ERRORS
       Default.
       The following sections are informative.
APPLICATION USAGE
       None.
EXAMPLES
              : ${X=abc}
              if     false
              then   :
              else   echo $X
              fi
              abc
       As with any of the special built-ins, the null utility  can  also  have
       variable assignments and redirections associated with it, such as:

              x=y : > z
       which  sets  variable  x  to the value y (so that it persists after the
       null utility completes) and creates or truncates file z.
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       Special Built-In Utilities
COPYRIGHT
       Portions of this text are reprinted and reproduced in  electronic  form
       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
       Specifications  Issue  6,  Copyright  (C) 2001-2003 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 .

IEEE/The Open Group                  2003                            COLON(1P)