#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <sys/wait.h>

int main()
{ char line[1000];
  while (1)
  { printf("Ready: ");
    char * s = fgets(line, 999, stdin);
    if (s == NULL)
      break;
    if (strcmp(line, "exit\n") == 0)
      break;
    else if (strcmp(line, "hello\n") == 0)
      printf("Hello to you too\n");  
    else if (strcmp(line, "files\n") == 0)
    { int s, p = fork();
      if (p == 0)
      { execlp("ls", "ls", "-l", NULL);
        printf("exec failed\n");
        exit(1); }
      p = wait(& s); }
    else
      printf("I don't understand %s", line); }
  printf("exitting\n"); }