text: #include "kernel/stat.h"
  #include "kernel/types.h"
  #include "user/user.h"
  
  int main(int argc, char **argv) {
    if (argc < 2) {
      fprintf(2, "usage: kill pid...\n");
      exit(1);
    }
    for (int i = 1; i < argc; i++) kill(atoi(argv[i]));
    exit(0);
  }
  