true man page

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.

true ā€” 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.1-2008, 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

Referenced By

false(1p).

2013 IEEE/The Open Group POSIX Programmer's Manual