C/stdlib.h/mbstowcs

    
//Declaration:  size_t mbstowcs(wchar_t *out, const char *in, size_t size); 
//Return:       returns the number of multibyte characters converted or -1 on error. 
#include <stdlib.h>
#include <stdio.h>
int main(void){
  char *mb = "asdfadsf";
  char str[1000];
  mbstowcs(str, mb, 4);
 
  printf("%s",str);
}
         
/*
a*/