add init process

openrc-init.c and openrc-shutdown.c are based on code which was written by
James Hammons <jlhamm@acm.org>, so I would like to publically
thank him for his work.

src/rc/openrc-shutdown.c

@@ -0,0 +1,119 @@
+/*
+ * openrc-shutdown.c
+ * If you are using OpenRC's provided init, this will shut down or
+ * reboot your system.
+ */
+
+/*
+ * Copyright 2017 The OpenRC Authors.
+ * See the Authors file at the top-level directory of this distribution and
+ * https://github.com/OpenRC/openrc/blob/master/AUTHORS
+ *
+ * This file is part of OpenRC. It is subject to the license terms in
+ * the LICENSE file found in the top-level directory of this
+ * distribution and at https://github.com/OpenRC/openrc/blob/master/LICENSE
+ * This file may not be copied, modified, propagated, or distributed
+ *    except according to the terms contained in the LICENSE file.
+ */
+
+#include <getopt.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+
+#include "einfo.h"
+#include "rc.h"
+#include "helpers.h"
+#include "_usage.h"
+
+const char *applet = NULL;
+const char *extraopts = NULL;
+const char *getoptstring = "kpr" getoptstring_COMMON;
+const struct option longopts[] = {
+	{ "halt",        no_argument, NULL, 'H'},
+	{ "kexec",        no_argument, NULL, 'k'},
+	{ "poweroff",        no_argument, NULL, 'p'},
+	{ "reboot",        no_argument, NULL, 'r'},
+	longopts_COMMON
+};
+const char * const longopts_help[] = {
+	"halt the system",
+	"reboot the system using kexec",
+	"power off the system",
+	"reboot the system",
+	longopts_help_COMMON
+};
+const char *usagestring = NULL;
+const char *exclusive = "Select one of --halt, --kexec, --poweroff or --reboot";
+
+static void send_cmd(const char *cmd)
+{
+	FILE *fifo;
+ 	size_t ignored;
+
+	fifo = fopen(RC_INIT_FIFO, "w");
+
+	if (!fifo) {
+		perror("fopen");
+		return;
+	}
+
+	ignored = fwrite(cmd, 1, strlen(cmd), fifo);
+	if (ignored != strlen(cmd))
+		printf("Error writing to init fifo\n");
+	fclose(fifo);
+}
+
+int main(int argc, char **argv)
+{
+	int opt;
+	int cmd_count = 0;
+	bool do_halt = false;
+	bool do_kexec = false;
+	bool do_poweroff = false;
+	bool do_reboot = false;
+
+	applet = basename_c(argv[0]);
+if (geteuid() != 0)
+	eerrorx("%s: you must be root\n", applet);
+	while ((opt = getopt_long(argc, argv, getoptstring,
+		    longopts, (int *) 0)) != -1)
+	{
+		switch (opt) {
+		case 'H':
+			do_halt = true;
+			cmd_count++;
+			break;
+		case 'k':
+			do_kexec = true;
+			cmd_count++;
+			break;
+		case 'p':
+			do_poweroff = true;
+			cmd_count++;
+			break;
+		case 'r':
+			do_reboot = true;
+			cmd_count++;
+			break;
+		case_RC_COMMON_GETOPT
+		}
+	}
+	if (cmd_count != 1) {
+		eerror("%s: %s\n", applet, exclusive);
+		usage(EXIT_FAILURE);
+	}
+	if (do_halt)
+		send_cmd("halt");
+	else if (do_kexec)
+		send_cmd("kexec");
+	else if (do_poweroff)
+		send_cmd("poweroff");
+	else if (do_reboot)
+		send_cmd("reboot");
+	return 0;
+}