Manual Reference Pages  - TRUE (P)

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.

CONTENTS

Name
Synopsis
Description
Options
Operands
Stdin
Input Files
Environment Variables
Asynchronous Events
Stdout
Stderr
Output Files
Extended Description
Exit Status
Consequences Of Errors
Application Usage
Examples
Rationale
Future Directions
See Also
Copyright

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 IEEE Std 1003.1-2001, 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

false , Shell Commands

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 TRUE (P) 2003
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