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)