wcsstr.c

C标准库源代码

/***
*wcsstr.c - search for one wide-character string inside another
*
*       Copyright (c) 1985-1997, Microsoft Corporation. All rights reserved.
*
*Purpose:
*       defines wcsstr() - search for one wchar_t string inside another
*
*******************************************************************************/


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

/***
*wchar_t *wcsstr(string1, string2) - search for string2 in string1
*       (wide strings)
*
*Purpose:
*       finds the first occurrence of string2 in string1 (wide strings)
*
*Entry:
*       wchar_t *string1 - string to search in
*       wchar_t *string2 - string to search for
*
*Exit:
*       returns a pointer to the first occurrence of string2 in
*       string1, or NULL if string2 does not occur in string1
*
*Uses:
*
*Exceptions:
*
*******************************************************************************/

wchar_t * __cdecl wcsstr (
        const wchar_t * wcs1,
        const wchar_t * wcs2
        )
{
        wchar_t *cp = (wchar_t *) wcs1;
        wchar_t *s1, *s2;

        while (*cp)
        {
                s1 = cp;
                s2 = (wchar_t *) wcs2;

                while ( *s1 && *s2 && !(*s1-*s2) )
                        s1++, s2++;

                if (!*s2)
                        return(cp);

                cp++;
        }

        return(NULL);
}