wcsdup.c

C标准库源代码,能提高对C的理解,不错的哦

/***
*wcsdup.c - duplicate a wide-character string in malloc'd memory
*
*       Copyright (c) 1985-1997, Microsoft Corporation. All rights reserved.
*
*Purpose:
*       defines _wcsdup() - grab new memory, and duplicate the string into it
*       (wide-character).
*
*******************************************************************************/


#include <cruntime.h>
#include <malloc.h>
#include <string.h>

/***
*wchar_t *_wcsdup(string) - duplicate string into malloc'd memory
*
*Purpose:
*       Allocates enough storage via malloc() for a copy of the
*       string, copies the string into the new memory, and returns
*       a pointer to it (wide-character).
*
*Entry:
*       wchar_t *string - string to copy into new memory
*
*Exit:
*       returns a pointer to the newly allocated storage with the
*       string in it.
*
*       returns NULL if enough memory could not be allocated, or
*       string was NULL.
*
*Uses:
*
*Exceptions:
*
*******************************************************************************/

wchar_t * __cdecl _wcsdup (
        const wchar_t * string
        )
{
        wchar_t *memory;

        if (!string)
                return(NULL);

        if (memory = (wchar_t *) malloc((wcslen(string)+1) * sizeof(wchar_t)))
                return(wcscpy(memory,string));

        return(NULL);
}