TRUE(P) POSIX Programmer's Manual 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.
NAMEtrue - return true value
SYNOPSIStrueDESCRIPTION
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 EXAM‐
PLES section. The special built-in utility : is sometimes more effi‐
cient 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 2003 TRUE(P)
