length.c

#include <stdio.h>
#include <stddef.h>
#include <wchar.h>
#include <locale.h>

int main () {
  setlocale(LC_ALL, "en_US.UTF-8");
  const wchar_t* wc = L"👌";
  int length = wcswidth(wc, 1);
  printf("%ls, length: %d\n", wc, length);
}