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## NAME

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

```

## SYNOPSIS

```       #include <math.h>

double frexp(double x, int *exp);
float frexpf(float x, int *exp);
long double frexpl(long double x, int *exp);

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

frexpf(), frexpl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600
|| _ISOC99_SOURCE; or cc -std=c99

```

## DESCRIPTION

```       The  frexp()  function  is used to split the number x into a normalized
fraction and an exponent which is stored in exp.

```

## RETURNVALUE

```       The frexp() function returns 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.

```

## ERRORS

```       No errors occur.

```

## CONFORMINGTO

```       C99, POSIX.1-2001.  The variant returning double also conforms to SVr4,
4.3BSD, C89.

```

## EXAMPLE

```       The program below produces results such as the following:

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

Program source

#include <math.h>
#include <float.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, FLT_RADIX, exp, x);
exit(EXIT_SUCCESS);
} /* main */

```

```       ldexp(3), modf(3)
```       This page is part of release 3.24 of the Linux  man-pages  project.   A