ubuntu-buildroot/output/build/glibc-2.36-81-g4f4d7a13edfd.../manual/examples/mbstouwcs.c

54 lines
1.2 KiB
C

#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
/* Do not include the above headers in the example.
*/
wchar_t *
mbstouwcs (const char *s)
{
/* Include the null terminator in the conversion. */
size_t len = strlen (s) + 1;
wchar_t *result = reallocarray (NULL, len, sizeof (wchar_t));
if (result == NULL)
return NULL;
wchar_t *wcp = result;
mbstate_t state;
memset (&state, '\0', sizeof (state));
while (true)
{
wchar_t wc;
size_t nbytes = mbrtowc (&wc, s, len, &state);
if (nbytes == 0)
{
/* Terminate the result string. */
*wcp = L'\0';
break;
}
else if (nbytes == (size_t) -2)
{
/* Truncated input string. */
errno = EILSEQ;
free (result);
return NULL;
}
else if (nbytes == (size_t) -1)
{
/* Some other error (including EILSEQ). */
free (result);
return NULL;
}
else
{
/* A character was converted. */
*wcp++ = towupper (wc);
len -= nbytes;
s += nbytes;
}
}
return result;
}