wcsstr

 

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Technical Specifications

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Strings library

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Wide strings

 

Null-terminated wide strings

Functions
Character manipulation
iswalnum (C95) iswalpha (C95) iswlower (C95) iswupper (C95) iswdigit (C95) iswxdigit (C95) iswblank (C99) wctype (C95) iswctype (C95)	iswcntrl (C95) iswgraph (C95) iswspace (C95) iswprint (C95) iswpunct (C95) towlower (C95) towupper (C95) wctrans (C95) towctrans (C95)
Conversions to numeric formats
wcstolwcstoll (C95)(C99) wcstoulwcstoull (C95)(C99)	wcstofwcstodwcstold (C99)(C95)(C99) wcstoimaxwcstoumax (C99)(C99)
String manipulation
wcslenwcsnlen_s (C95)(C11) wcscpywcscpy_s (C95)(C11) wcsncpywcsncpy_s (C95)(C11) wcscatwcscat_s (C95)(C11) wcsncatwcsncat_s (C95)(C11) wcsstr (C95)	wcscmp (C95) wcsncmp (C95) wcscoll (C95) wcsxfrm (C95) wcschr (C95) wcsrchr (C95) wcspbrk (C95) wcsspn (C95) wcscspn (C95) wcstokwcstok_s (C95)(C11)
Array manipulation
wmemcpywmemcpy_s (C95)(C11) wmemmovewmemmove_s (C95)(C11)	wmemcmp (C95) wmemchr (C95) wmemset (C95)

 

Defined in header <wchar.h>
wchar_t *wcsstr( const wchar_t *dest, const wchar_t *src );	(1)	(since C95)
/*QWchar_t*/ *wcsstr( /*QWchar_t*/ *dest, const wchar_t *src );	(2)	(since C23)

1) Finds the first occurrence of the wide string src in the wide string pointed to by dest. The terminating null characters are not compared.

2) Type-generic function equivalent to (1). Let T be an unqualified wide character object type.

• If dest is of type const T*, the return type is const wchar_t*.
• Otherwise, if dest is of type T*, the return type is wchar_t*.
• Otherwise, the behavior is undefined.

If a macro definition of each of these generic functions is suppressed to access an actual function (e.g. if (wcsstr) or a function pointer is used), the actual function declaration (1) becomes visible.

Parameters

dest	-	pointer to the null-terminated wide string to examine
src	-	pointer to the null-terminated wide string to search for

Return value

Pointer to the first character of the found substring in dest, or a null pointer if no such substring is found. If src points to an empty string, dest is returned.

Example

Run this code

#include <stdio.h>
#include <locale.h>
#include <wchar.h>
 
int main(void)
{
    setlocale(LC_ALL, "ru_RU.UTF-8");
 
    wchar_t str[5][64] = {
        L"Строка, где есть подстрока 'но'.",
        L"Строка, где такой подстроки нет.",
        L"Он здесь.",
        L"Здесь он.",
        L"Его нет."
    };
 
    for (size_t i = 0; i < 5; ++i) {
        if (wcsstr(str[i], L"но")) {
            wprintf(L"%ls\n", str[i]);
        }
    }
}

Output:

Строка, где есть подстрока 'но'.

References

• C11 standard (ISO/IEC 9899:2011):

• 7.29.4.5.6 The wcsstr function (p: 437)

• C99 standard (ISO/IEC 9899:1999):

• 7.24.4.5.6 The wcsstr function (p: 383)

See also

wcschr (C95)	finds the first occurrence of a wide character in a wide string (function)
wcsrchr (C95)	finds the last occurrence of a wide character in a wide string (function)
C++ documentation for wcsstr