test.c

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

int main(void)
{
        int fd0;

        fd0 = open("/tmp/tap0", O_RDWR);
        if (fd0 < 0) {
                perror("open");
                return 1;
        }

        while(1) {
                sleep(1);
        }

        return 0;
}

test.sh

#!/bin/bash

set -e

# tap0
ip tuntap add dev tap0 mode tap user root
ip addr add 10.2.2.2/24 dev tap0
ip link set tap0 up
mknod /tmp/tap0 c 10 200