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


int main(int argc, char**argv) {

  if(argc != 2) {
    fprintf(stderr, "Usage: %s <dirname>\n", argv[0]);
    return EXIT_FAILURE;
  }

  /* run command 'ls <dirname>' and output the result in f */
  char command[1024];
  sprintf(command, "ls %s", argv[1]);
  FILE *f = popen(command, "r");
  printf("Entering %s\n", argv[1]);
  sleep(1);
  char* ret = NULL;
  do {
    char filename[1024];
    ret = fgets(filename, 1024, f);
    if(!ret) {
      break;
    }
    char* substr = strstr(filename, "\n");
    if(substr) {
      substr[0]='\0';
    }

    char full_filename[1024];
    snprintf(full_filename, 1024, "%s/%s", argv[1], filename);

    struct stat s;
    stat(full_filename, &s);

    if(s.st_mode & S_IFDIR) {
      printf("New directory: %s\n", full_filename);

      /* create a new process and run recursively */
      int ret = fork();
      if(ret == 0) {
	execlp(argv[0], argv[0], (char*)full_filename, (char*)NULL);
	perror("execle");
      } else if(ret > 0){
	/* wait for the child process */
	int status;
	int ret = wait(&status);
	if(ret < 0) {
	  perror("wait");
	}
      } else {
	perror("fork");
      }
    } else {
      printf("New file: %s\n", full_filename);
    }

  } while(ret);
  printf("Leaving %s\n", argv[1]);

  pclose(f);

  return EXIT_SUCCESS;
}