// Modified from https://lwn.net/Articles/533492/
// Copyright 2013, Michael Kerrisk
// Licensed under GNU General Public License v2 or later

#define _GNU_SOURCE
#include <sched.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <signal.h>
#include <stdio.h>
#include <sys/mount.h>

/* A simple error-handling function: print an error message based
   on the value in 'errno' and terminate the calling process */

#define errExit(msg)    do { perror(msg); exit(EXIT_FAILURE); \
} while (0)

/* Start function for cloned child */
static int childFunc(void *arg)
{
	char **argv = arg;

	// TODO: Mise en place pour le processus fils

	execvp(argv[0], &argv[0]);
	errExit("execvp");
}

/* Space for child's stack */
#define STACK_SIZE (1024 * 1024)
static char child_stack[STACK_SIZE];

int main(int argc, char *argv[])
{
	int flags = 0;
	pid_t child_pid;

	// TODO: mise en place du flag pour le PID namespace

	child_pid = clone(childFunc, child_stack + STACK_SIZE, flags | SIGCHLD, &argv[1]);

	if (child_pid == -1)
		errExit("clone");

	printf("%s: PID of child created by clone() is %ld\n", argv[0], (long) child_pid);

	/* Parent falls through to here */

	if (waitpid(child_pid, NULL, 0) == -1)      /* Wait for child */
		errExit("waitpid");

	printf("%s: terminating\n", argv[0]);
	exit(EXIT_SUCCESS);
}