ISINF(3) BSD Programmer's Manual ISINF(3)NAME
isinf, isnan - test for infinity or not-a-number
SYNOPSIS
#include <math.h>
int
isinf(double);
int
isnan(double);
DESCRIPTION
The isninf() function returns 1 if the number is ``infinity'', otherwise
0.
The isnan() function returns 1 if the number is ``not-a-number'', other-
wise 0.
SEE ALSOmath(3)
IEEE Standard for Binary Floating-Point Arithmetic, Std 754-1985, ANSI.
BUGS
Neither the VAX nor the Tahoe floating point have distinguished values
for either infinity or not-a-number. These routines always return 0 on
those architectures.
BSDI BSD/OS January 29, 1994 1