#include <stdio.h>
#include <string.h>

int main(void) {
  char a[100], b[10] = "abcdefghi";

  //memset(a, ' ', sizeof a - 1);
  //a[sizeof a - 1] = 0;
  memset(a, ' ', sizeof a);
  memcpy(a, b, strlen(b));
  printf("a is [%.99s]\n", a);
  return 0;
}