linux-kernel-module-cheat/packages/kernel_modules/user/init_env_poweroff.c

#define _XOPEN_SOURCE 700
#include <stdio.h>
#include <sys/reboot.h>
#include <unistd.h>

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

	puts("args:");
	for (i = 0; i < argc; ++i)
		puts(argv[i]);
	puts("");

	puts("env:");
	extern char **environ;
	char **env = environ;
	while (*env) {
		printf("%s\n", *env);
		env++;
	}
	puts("");

	/* Poweroff. */
	reboot(RB_POWER_OFF);
}