util-src/pposix.c

/* Prosody IM v0.1
-- Copyright (C) 2008 Matthew Wild
-- Copyright (C) 2008 Waqas Hussain
-- 
-- 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; either version 2
-- of the License, or (at your option) any later version.
-- 
-- 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, write to the Free Software
-- Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*/

/* pposix.c
   POSIX support functions for Lua
*/

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

#include "lua.h"

static int daemonize(lua_State *L)
{

	pid_t pid;
	
	if ( getppid() == 1 )
	{
		lua_pushboolean(L, 0);
		lua_pushstring(L, "already-daemonized");
		return 2;
	}
	
	/* Attempt initial fork */
	if((pid = fork()) < 0)
	{
		/* Forking failed */
		lua_pushboolean(L, 0);
		lua_pushstring(L, "fork-failed");
		return 2;
	}
	else if(pid != 0)
	{
		/* We are the parent process */
		lua_pushboolean(L, 1);
		lua_pushnumber(L, pid);
		return 2;
	}
	
	/* and we are the child process */
	if(setsid() == -1)
	{
		/* We failed to become session leader */
		/* (we probably already were) */
		lua_pushboolean(L, 0);
		lua_pushstring(L, "setsid-failed");
		return 2;
	}

	/* Close stdin, stdout, stderr */
/*	close(0);
	close(1);
	close(2);
*/
	/* Final fork, use it wisely */
	if(fork())
		exit(0);

	/* Show's over, let's continue */
	lua_pushboolean(L, 1);
	lua_pushnil(L);
	return 2;
}

int luaopen_util_pposix(lua_State *L)
{
	lua_newtable(L);
	lua_pushcfunction(L, daemonize);
	lua_setfield(L, -2, "daemonize");
	return 1;
};