ISINF
Section: POSIX Programmer's Manual (3P)
Updated: 2003
Index
Return to Main Contents
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
isinf - test for infinity
SYNOPSIS
#include <math.h>
int isinf(real-floating x);
DESCRIPTION
The isinf() macro shall determine whether its argument value
is an infinity (positive or negative). First, an argument
represented in a format wider than its semantic type is converted
to its semantic type. Then determination is based on the type of
the argument.
RETURN VALUE
The isinf() macro shall return a non-zero value if and only
if its argument has an infinite value.
ERRORS
No errors are defined.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
fpclassify(), isfinite(), isnan(), isnormal(),
signbit(), the
Base Definitions volume of IEEE Std 1003.1-2001 <math.h>
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 .