HP-UX Reference (11i v1 05/09) - 3 Library Functions A-M (vol 6)

i
isinf(3M) isinf(3M)
NAME
isinf( ) - floating-point test for infinity
SYNOPSIS
#include <math.h>
int isinf(
floating-type x);
DESCRIPTION
The isinf() macro determines whether its argument value is an infinity. The macro can be used with
either double or float arguments.
The ISO/ANSI C committee has approved the
isinf() macro for inclusion in the C9X draft standard.
To use this macro, compile either with the default
-Ae option or with the -Aa and -D_HPUX_SOURCE
options. Make sure your program includes <
math.h>. Link in the math library by specifying -lm on the
compiler or linker command line.
The
isinf() macro replaces the isinf() and
isinff() functions, which are obsolete and are no
longer supported.
RETURN VALUE
The
isinf() macro returns a nonzero value if x is ±INFINITY. Otherwise it returns zero.
EXAMPLE
Take certain actions if x is infinity:
#include <math.h>
/*...*/
float x;
/*...*/
if (isinf(x))
/*...*/
ERRORS
No errors are defined.
SEE ALSO
fpclassify(3M), isfinite(3M), isnan(3M), isnormal(3M), signbit(3M), math(5).
HP-UX 11i Version 1: September 2005 − 1 − Hewlett-Packard Company Section 3−−505