FINITE(3)                 Linux Programmer's Manual                FINITE(3)

NAME         top

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

SYNOPSIS         top

       #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
           _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 ||
           or cc -std=c99
       isinff(), isinfl():
           _BSD_SOURCE || _SVID_SOURCE
           or cc -std=c99
       isnanf(), isnanl():
           _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600

DESCRIPTION         top

       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         top

       For an explanation of the terms used in this section, see

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

NOTES         top

       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         top


COLOPHON         top

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                                 2015-03-02                        FINITE(3)