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); |
![[Note]](../stylesheet/note.png) |
Note | ||||||
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DESCRIPTION
The finite() functions
return a nonzero value if x is neither infinite nor a
"not-a-number" (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 plus
infinity, −1 is x is minus 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 fpclassify(3).
COLOPHON
This page is part of release 2.79 of the Linux man-pages project. A
description of the project, and information about reporting
bugs, can be found at
http://www.kernel.org/doc/man-pages/.
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Copyright 2004 Andries Brouwer <aebcwi.nl>. 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 Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. |