ISINFF(3) | Library Functions Manual | ISINFF(3)

# NAME

isinff, isnanf — test for infinity or not-a-number

# LIBRARY

Math Library (libm, -lm)

# SYNOPSIS

#include <math.h>
int
isinff(float);
int
isnanf(float);

# DESCRIPTION

The isinff() function returns 1 if the number is “infinity”, otherwise 0.
The isnanf() function returns 1 if the number is “not-a-number”, otherwise 0.

# SEE ALSO

isinf(3), isnan(3), math(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.

August 16, 1999 | NetBSD 8.2