finitef (3)

Leading comments

Copyright 2004 Andries Brouwer <aeb@cwi.nl>.

%%%LICENSE_START(VERBATIM)
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.

Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.

Since the Linu...

(The comments found at the beginning of the groff file "man3/finitef.3".)

NAME

finite, finitef, finitel, isinf, isinff, isinfl, isnan, isnanf, isnanl - BSD floating-point classification functions

SYNOPSIS

#include <math.h>

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():

_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE;
or cc -std=c99

isinff(), isinfl():

_BSD_SOURCE || _SVID_SOURCE

isnan():

_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE || _ISOC99_SOURCE;
or cc -std=c99

isnanf(), isnanl():

_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600

DESCRIPTION

The finite(), finitef(), and finitel() functions return a nonzero value if x is neither infinite nor a "not-a-number" (NaN) value, and 0 otherwise.
The isnan(), isnanf(), and isnanl() functions return a nonzero value if x is a NaN value, and 0 otherwise.
The isinf(), isinff(), and isinfl() functions return 1 if x is positive infinity, -1 if x is negative infinity, and 0 otherwise.

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).

Interface	Attribute	Value
finite(), finitef(), finitel(), isinf(), isinff(), isinfl(), isnan(), isnanf(), isnanl()	Thread safety	MT-Safe

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 fpclassify(3).

SEE ALSO

fpclassify(3)

COLOPHON

This page is part of release 4.04 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at www.kernel.org/doc/man-pages