jailer.c

#include <dirent.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/param.h>
#include <sys/jail.h>
#include <sys/uio.h>
#include <sys/types.h>

int
main(int argc, char** argv) {
  struct jail jp;

  jp.version = 0;
  jp.path = "/zroot/jails/build";
  jp.hostname = "test1";
  jp.jailname = "test1";

  int jid;
  jid = jail(&jp);
  if (jid == -1) {
    perror("jail");
    return EXIT_FAILURE;
  }
  printf("JAIL ID: %d\n", jid);
  sleep(5);

  int fd = creat("/hello_from_c", 0666);
  close(fd);

  DIR *dp;
  struct dirent *ep;

  dp = opendir("/");
  if (dp != NULL) {
      while ((ep = readdir(dp)))
        puts (ep->d_name);
      (void) closedir (dp);
    }
  else
    perror ("Couldn't open the directory");

  return EXIT_SUCCESS;
}