HP-UX Reference (11i v2 07/12) - 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 is an infinity. The argument must be of floating
type, and classification is based on the type of the argument. For Itanium(R)-based systems, the argument
can be any floating type. For PA-RISC, the argument must be either
double or
float.
The
isinf() macro replaces the isinf() and isinff()
functions, which are obsolete and are no
longer supported.
USAGE
To use the
isinf() 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.
RETURN VALUE
The isinf() macro returns a nonzero value if x is ±INFINITY. Otherwise, it returns zero. The macro
raises no floating-point exceptions.
ERRORS
No errors are defined.
EXAMPLES
Take certain actions if x is infinity:
#include <math.h>
/*...*/
float x;
/*...*/
if (isinf(x))
/*...*/
SEE ALSO
fpclassify(3M), isfinite(3M), isnan(3M), isnormal(3M), signbit(3M), math(5).
STANDARDS CONFORMANCE
isinf(): ISO/IEC C99
672 Hewlett-Packard Company − 1 − HP-UX 11i Version 2: December 2007 Update