C语言库wctomb()函数

#include <stdio.h>
#include <stdlib.h>

int main () {
   int i;
   wchar_t wc = L'a';
   char *pmbnull = NULL;
   char *pmb = (char *)malloc(sizeof( char ));

   printf("Converting wide character:/n");
   i = wctomb( pmb, wc );
   printf("Characters converted: %u/n", i);
   printf("Multibyte character: %.1s/n", pmb);

   printf("Trying to convert when target is NULL:/n");
   i = wctomb( pmbnull, wc );
   printf("Characters converted: %u/n", i);

   /* this will not print any value */
   printf("Multibyte character: %.1s/n", pmbnull);

   return(0);
}