FINITE(3) Linux Programmers Manual FINITE(3)
NAME
finite, finitef, finitel, isinf, isinff, isinfl, isnan, isnanf, isnanl
 BSD floatingpoint classification functions
SYNOPSIS
#include
int finite(double x);
int finitef(float x);
int finitel(long double x);
int isinf(double x);
int isinff(float x);
int isinfl(long double x);
int isnan(double x);
int isnanf(float x);
int isnanl(long double x);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
finite(), finitef(), finitel(): _BSD_SOURCE  _SVID_SOURCE
isinf(), isinff(), isinfl(): _BSD_SOURCE  _SVID_SOURCE
isnan(), isnanf(), isnanl(): _BSD_SOURCE  _SVID_SOURCE 
_XOPEN_SOURCE
DESCRIPTION
The finite() functions return a nonzero value if x is neither infinite
nor a "notanumber" (NaN) value, and 0 otherwise.
The isnan() functions return a nonzero value if x is a NaN value, and
0 otherwise.
The isinf() functions return 1 if x is positive infinity, 1 is x is
negative infinity, and 0 otherwise.
NOTES
Note that these functions are obsolete. C99 defines macros isfinite(),
isinf(), and isnan() (for all types) replacing them. Further note that
the C99 isinf() has weaker guarantees on the return value. See fpclas
sify(3).
SEE ALSO
fpclassify(3)
COLOPHON
This page is part of release 3.05 of the Linux manpages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/manpages/.
20070726 FINITE(3)
