init: poweroff program

tools/init/poweroff.c

@@ -0,0 +1,24 @@
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "common.h"
+
+int main() {
+	char c = COMMAND_POWEROFF;
+	int fd = open(COMMAND_FIFO, O_WRONLY);
+
+	if (fd == -1) {
+		perror("poweroff: open");
+		return EXIT_FAILURE;
+	}
+
+	if (write(fd, &c, 1)) {
+		perror("poweroff: write");
+		return EXIT_FAILURE;
+	}
+
+	close(fd);
+	return EXIT_SUCCESS;
+}