wtombenv.c

C标准库源代码

/***
*wtombenv.c - convert wide environment block to multibyte
*
*       Copyright (c) 1993-1997, Microsoft Corporation. All rights reserved.
*
*Purpose:
*       defines __wtomb_environ(). Create a multibyte equivalent of
*       an existing wide character environment block.
*
*******************************************************************************/


#include <windows.h>
#include <cruntime.h>
#include <internal.h>
#include <stdlib.h>
#include <dbgint.h>

/***
*__wtomb_environ - copy wide environment block to multibyte environment block
*
*Purpose:
*       Create a multibyte equivalent of an existing wide character
*       environment block.
*
*Entry:
*       Assume _wenviron (global pointer) points to existing wide
*       environment block.
*
*Exit:
*       If success, every wide environment variable has been added to
*       the multibyte environment block and returns 0.
*       If failure, returns -1.
*
*Exceptions:
*       If space cannot be allocated, returns -1.
*
*******************************************************************************/

int __cdecl __wtomb_environ (
        void
        )
{
        char *envp;
        wchar_t **wenvp = _wenviron;

        /*
         * For every environment variable in the multibyte environment,
         * convert it and add it to the wide environment.
         */

        while (*wenvp)
        {
            int size;

            /* find out how much space is needed */
            if ((size = WideCharToMultiByte(CP_OEMCP, 0, *wenvp, -1, NULL, 0, NULL, NULL)) == 0)
                return -1;

            /* allocate space for variable */
            if ((envp = (char *) _malloc_crt(size * sizeof(char))) == NULL)
                return -1;

            /* convert it */
            if (WideCharToMultiByte(CP_OEMCP, 0, *wenvp, -1, envp, size, NULL, NULL) == 0)
                return -1;

            /* set it - this is not primary call, so set primary == 0 */
            __crtsetenv(envp, 0);

            wenvp++;
        }

        return 0;
}