modfl(3) — Linux manual page


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

NAME         top

       modf,  modff,  modfl  - extract signed integral and fractional values
       from floating-point number

SYNOPSIS         top

       #include <math.h>

       double modf(double x, double *iptr);
       float modff(float x, float *iptr);
       long double modfl(long double x, long double *iptr);

       Link with -lm.

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       modf(), modfl():
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
               || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION         top

       These functions break the argument x into an integral part and a
       fractional part, each of which has the same sign as x.  The integral
       part is stored in the location pointed to by iptr.

RETURN VALUE         top

       These functions return the fractional part of x.

       If x is a NaN, a NaN is returned, and *iptr is set to a NaN.

       If x is positive infinity (negative infinity), +0 (-0) is returned,
       and *iptr is set to positive infinity (negative infinity).

ERRORS         top

       No errors occur.

ATTRIBUTES         top

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

       │Interface                Attribute     Value   │
       │modf(), modff(), modfl() │ Thread safety │ MT-Safe │

CONFORMING TO         top

       C99, POSIX.1-2001, POSIX.1-2008.

       The variant returning double also conforms to SVr4, 4.3BSD, C89.

SEE ALSO         top

       frexp(3), ldexp(3)

COLOPHON         top

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       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at

                                 2017-09-15                          MODF(3)