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 nothing 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(P)