# isinf(3) [netbsd man page]

```ISINF(3)						   BSD Library Functions Manual 						  ISINF(3)

NAME
isinf -- test for infinity

LIBRARY
Standard C Library (libc, -lc)

SYNOPSIS
#include <math.h>

int
isinf(real-floating x);

DESCRIPTION
The isinf() macro determines whether its argument x is an infinity (positive or negative).  An argument represented in a format wider than
its semantic type is converted to its semantic type first.  The determination is then based on the type of the argument.

IEEE 754
It is determined whether the value of x is an infinity.

VAX
Infinities are not supported.

RETURN VALUES
The isinf() macro returns a non-zero value if the value of x is an infinity.  Otherwise 0 is returned.

fpclassify(3), isfinite(3), isinff(3), isnan(3), isnanf(3), isnormal(3), math(3), signbit(3)

IEEE Standard for Binary Floating-Point Arithmetic, Std 754-1985, ANSI.

STANDARDS
The isinf() macro conforms to ISO/IEC 9899:1999 (``ISO C99'').

BSD								   March 5, 2004							       BSD```

## Check Out this Related Man Page

```isinf(3M)						  Mathematical Library Functions						 isinf(3M)

NAME
isinf - test for infinity

SYNOPSIS
#include <math.h>

int isinf(real-floating x);

DESCRIPTION
The  isinf()  macro determines 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 VALUES
The isinf() macro returns a non-zero value if and only if its argument has an infinite value.

ERRORS
No errors are defined.

ATTRIBUTES
See attributes(5) for descriptions of the following attributes:

+-----------------------------+-----------------------------+
|      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
+-----------------------------+-----------------------------+
|Interface Stability	     |Standard			   |
+-----------------------------+-----------------------------+
|MT-Level		     |MT-Safe			   |
+-----------------------------+-----------------------------+