#include <stdlib.h>

#include <locale.h>

#include <errno.h>

 

extern int errno;



/*

 * The following example uses the wcstod subroutine to convert

 * a wide character string to a double-precision floating point

 */

int main(int argc, char **argv) {

    wchar_t  *pwcs, *endptr;

    double   retval;

 

    setlocale(LC_ALL, "");

    

    /*

     * Let pwcs point to a wide character null terminated

     * string containing a floating point value.

     */

    errno = 0; /*  set errno to  zero  */

    retval = wcstod(pwcs, &endptr);

 

    if(errno != 0) { /*  errno has changed, so error has occurred */

        if (errno == ERANGE){

          

            /* 

             * correct value is outside range of

             * representable values. Case of overflow

             * error

             */

            if ((retval == HUGE_VAL) || (retval == -HUGE_VAL)){

                /* Error case. Handle accordingly.  */

            } else if (retval == 0){

                /* correct value causes underflow   */

                /* Handle appropriately             */

            }

        }

    }

    /*  retval contains the double.  */

    printf("Double from wide-character: %d\n", retval);

    return (0);

}