others
/* $Id$ */
/* Copyright (c) 2009-2014 Pierre Pronchery <khorben@defora.org> */
/* This file is part of DeforaOS Unix others */
/* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 3 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <sys/wait.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
/* oinit */
/* private */
/* constants */
#define PROGNAME "oinit"
/* prototypes */
static int _oinit(void);
static int _error(char const * message, int ret);
/* functions */
/* oinit */
static void _oinit_child(void);
static int _oinit(void)
{
pid_t pid;
/* spawn a process to initialize the system */
if((pid = fork()) == -1)
return -_error("fork", 1);
else if(pid == 0)
_oinit_child();
return 0;
}
static void _oinit_child(void)
{
const char rc[] = "/etc/rc";
char * const rc_argv[] = { "rc", NULL };
const char sh[] = "/bin/sh";
char * const sh_argv[] = { "sh", "-i", NULL };
if(setsid() == -1)
_error("setsid", 1);
else if(setpgid(0, 0) != 0)
_error("setpgid", 1);
/* start /etc/rc */
execve(rc, rc_argv, NULL);
_error(rc, 1);
/* start a backup shell */
execv(sh, sh_argv);
_error(sh, 1);
_exit(errno);
}
/* error */
static int _error(char const * message, int ret)
{
fputs(PROGNAME ": ", stderr);
perror(message);
return ret;
}
/* public */
/* functions */
/* main */
int main(void)
{
const char console[] = "/dev/console";
if(getpid() == 1)
{
/* open stdin, stdout and stderr on the console */
if(open(console, O_RDONLY) != 0)
_error("stdin", 1);
if(open(console, O_WRONLY) != 1)
_error("stdout", 1);
if(open(console, O_WRONLY) != 2)
_error("stderr", 1);
}
_oinit();
for(;;)
if(wait(NULL) == -1)
{
if(errno == ECHILD)
/* restart init if there is no process left */
_oinit();
else
/* report the error */
_error("wait", 1);
}
return 0;
}