virli/tutorial/4/setns-samples.md

#### Exemple C

Voici un exemple de code C utilisant `setns(2)` :

<div lang="en-US">
```c
#define _GNU_SOURCE
#include <fcntl.h>
#include <sched.h>
#include <stdlib.h>

// ./a.out /proc/PID/ns/FILE cmd args...

int
main(int argc, char *argv[])
{
    int fd = open(argv[1], O_RDONLY);
    if (fd == -1)
    {
      perror("open");
      return EXIT_FAILURE;
    }

    if (setns(fd, 0) == -1)
    {
      perror("setns");
      return EXIT_FAILURE;
    }

    execvp(argv[2], &argv[2]);

    perror("execve");
    return EXIT_FAILURE;
}
```
</div>


#### Exemple shell

Dans un shell, on utilisera la commande `nsenter(1)` :

<div lang="en-US">
```bash
42sh# unshare --uts /bin/bash
  inutsns# echo $$
  42
  inutsns# hostname jument
  # Keep this shell active to perform nexts steps, in another shell.

42sh# hostname
chaton
42sh# nsenter --uts=/proc/42/ns/uts /bin/bash
  inutsns# hostname
  jument
```
</div>