true(1p) — Linux manual page

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

       true — return true value

SYNOPSIS

       true

DESCRIPTION

       The true utility shall return with exit code zero.

OPTIONS

       None.

OPERANDS

       None.

STDIN

       Not used.

INPUT FILES

       None.

ENVIRONMENT VARIABLES

       None.

ASYNCHRONOUS EVENTS

       Default.

STDOUT

       Not used.

STDERR

       Not used.

OUTPUT FILES

       None.

EXTENDED DESCRIPTION

       None.

EXIT STATUS

       Zero.

CONSEQUENCES OF ERRORS

       None.

       The following sections are informative.

APPLICATION USAGE

       This utility is typically used in shell scripts, as shown in the
       EXAMPLES section. The special built-in utility : is sometimes
       more efficient than true.

EXAMPLES

       This command is executed forever:

           while true
           do
               command
           done

RATIONALE

       The true utility has been retained in this volume of
       POSIX.1‐2017, even though the shell special built-in : provides
       similar functionality, because true is widely used in historical
       scripts and is less cryptic to novice script readers.

FUTURE DIRECTIONS

       None.

SEE ALSO

       Section 2.9, Shell Commands, false(1p)

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 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 .

       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               2017                          TRUE(1P)

Pages that refer to this page: false(1p)

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