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

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 .