frexp, frexpf, frexpl - convert floating-point number to fractional and integral components

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

       These functions are used to split the number x into a normalized fraction and an exponent which is stored
       in exp.

       No errors occur.

       The program below produces results such as the following:

           $ ./a.out2560
           frexp(2560, &e) = 0.625: 0.625 * 2^12 = 2560
           $ ./a.out-4
           frexp(-4, &e) = -0.5: -0.5 * 2^3 = -4

   Programsource

       #include <float.h>
       #include <math.h>
       #include <stdio.h>
       #include <stdlib.h>

       int
       main(int argc, char *argv[])
       {
           double x, r;
           int exp;

           x = strtod(argv[1], NULL);
           r = frexp(x, &exp);

           printf("frexp(%g, &e) = %g: %g * %d^%d = %g\n", x, r, r, 2, exp, x);
           exit(EXIT_SUCCESS);
       }

       C99, POSIX.1-2001.

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

       Math library (libm, -lm)

       frexp, frexpf, frexpl - convert floating-point number to fractional and integral components

       These  functions  return the normalized fraction.  If the argument x is not zero, the normalized fraction
       is x times a power of two, and  its  absolute  value  is  always  in  the  range  1/2  (inclusive)  to  1
       (exclusive), that is, [0.5,1).

       If x is zero, then the normalized fraction is zero and zero is stored in exp.

       If x is a NaN, a NaN is returned, and the value of *exp is unspecified.

       If x is positive infinity (negative infinity), positive infinity (negative infinity) is returned, and the
       value of *exp is unspecified.

ldexp(3), modf(3)

Linux man-pages 6.9.1                              2024-06-15                                           frexp(3)

       C11, POSIX.1-2008.

#include<math.h>doublefrexp(doublex,int*exp);floatfrexpf(floatx,int*exp);longdoublefrexpl(longdoublex,int*exp);

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

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