mbstowcs(3) Library Functions Manual mbstowcs(3) mbstowcs - (libc -lc) #include size_t mbstowcs(size_t dsize; wchar_t dest[restrict dsize], const char *restrict src, size_t dsize); dest NULL src dest. dsize dest. src . : o . (size_t) -1. o dsize L'\0' dest. dest . o ('\0'). dest . dest (NULL) dsize . 2 dsize mbstowcs(NULL,src,0)+1. dsize dest. . (size_t) -1. attributes(7). +------------+------------------------------------+--------------------+ || | | +------------+------------------------------------+--------------------+ |mbstowcs() | | MT-Safe | +------------+------------------------------------+--------------------+ mbsrtowcs(3) . C11, POSIX.1-2008. POSIX.1-2001 C99. mbstowcs() LC_CTYPE . mbstowcs() . : $ ./t_mbstowcs de_DE.UTF-8 Grusse! Length of source string (excluding terminator): 8 bytes 6 multibyte characters Wide character string is: Grusse! (6 characters) G alpha upper r alpha lower u alpha lower ss alpha lower e alpha lower ! !alpha #include #include #include #include #include #include int main(int argc, char *argv[]) { size_t mbslen; /* Number of multibyte characters in source */ wchar_t *wcs; /* Pointer to converted wide character string */ if (argc < 3) { fprintf(stderr, "Usage: %s \n", argv[0]); exit(EXIT_FAILURE); } /* Apply the specified locale. */ if (setlocale(LC_ALL, argv[1]) == NULL) { perror("setlocale"); exit(EXIT_FAILURE); } /* Calculate the length required to hold argv[2] converted to a wide character string. */ mbslen = mbstowcs(NULL, argv[2], 0); if (mbslen == (size_t) -1) { perror("mbstowcs"); exit(EXIT_FAILURE); } /* Describe the source string to the user. */ printf("Length of source string (excluding terminator):\n"); printf(" %zu bytes\n", strlen(argv[2])); printf(" %zu multibyte characters\n\n", mbslen); /* Allocate wide character string of the desired size. Add 1 to allow for terminating null wide character (L'\0'). */ wcs = calloc(mbslen + 1, sizeof(*wcs)); if (wcs == NULL) { perror("calloc"); exit(EXIT_FAILURE); } /* Convert the multibyte character string in argv[2] to a wide character string. */ if (mbstowcs(wcs, argv[2], mbslen + 1) == (size_t) -1) { perror("mbstowcs"); exit(EXIT_FAILURE); } printf("Wide character string is: %ls (%zu characters)\n", wcs, mbslen); /* Now do some inspection of the classes of the characters in the wide character string. */ for (wchar_t *wp = wcs; *wp != 0; wp++) { printf(" %lc ", (wint_t) *wp); if (!iswalpha(*wp)) printf("!"); printf("alpha "); if (iswalpha(*wp)) { if (iswupper(*wp)) printf("upper "); if (iswlower(*wp)) printf("lower "); } putchar('\n'); } exit(EXIT_SUCCESS); } mblen(3), mbsrtowcs(3), mbtowc(3), wcstombs(3), wctomb(3) 3 . . : . 6.18 8 2026 mbstowcs(3)