colon(1)              MPE/iX Shell and Utilities              colon(1)
  ______________________________________________________________________

  NAME
       : (colon) -- do nothing, successfully

  SYNOPSIS
       : [argument ...]

  DESCRIPTION
       The : (colon) command simply yields an exit status of zero (suc-
       cess).  This can be surprisingly useful, for example, when you
       are evaluating shell expressions for their side effects.

  EXAMPLES

           : ${VAR:="default value"}

       sets VAR to a default value if and only if it is not already set.

  DIAGNOSTICS
       Since this command always succeeds, the only possible exit status
       is:

       0  Successful completion.

  Messages
       Because this utility is built into the MPE/iX Shell, see the
       sh(1) man page for a complete list of error messages that you may
       receive when using it.

  PORTABILITY
       POSIX.2.  x/OPEN Portability Guide 4.0.  All UNIX systems.

  NOTE
       This is a special built-in command of the shell.

  SEE ALSO
       sh(1), true(1)

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