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

Attributes

       For an explanation of the terms used in this section, see attributes(7).
       ┌─────────────────────────────────────────────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                                                                   │ Attribute     │ Value   │
       ├─────────────────────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │ modf(), modff(), modfl()                                                    │ Thread safety │ MT-Safe │
       └─────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘

Description

       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.

Errors

       No errors occur.

History

       C99, POSIX.1-2001.

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

Library

       Math library (libm, -lm)

Name

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

Return Value

       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).

Standards

       C11, POSIX.1-2008.

Synopsis

#include<math.h>doublemodf(doublex,double*iptr);floatmodff(floatx,float*iptr);longdoublemodfl(longdoublex,longdouble*iptr);

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

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