true(1p) — Linux manual page

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

PROLOG         top

       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         top

       true — return true value

SYNOPSIS         top

       true

DESCRIPTION         top

       The true utility shall return with exit code zero.

OPTIONS         top

       None.

OPERANDS         top

       None.

STDIN         top

       Not used.

INPUT FILES         top

       None.

ENVIRONMENT VARIABLES         top

       None.

ASYNCHRONOUS EVENTS         top

       Default.

STDOUT         top

       Not used.

STDERR         top

       Not used.

OUTPUT FILES         top

       None.

EXTENDED DESCRIPTION         top

       None.

EXIT STATUS         top

       Zero.

CONSEQUENCES OF ERRORS         top

       None.

       The following sections are informative.

APPLICATION USAGE         top

       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         top

       This command is executed forever:

           while true
           do
               command
           done

RATIONALE         top

       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         top

       None.

SEE ALSO         top

       Section 2.9, Shell Commands, false(1p)

COPYRIGHT         top

       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)

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