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/*
daemon.c - implementation of daemon() for systems that lack it
Copyright (C) 2002, 2003 Arthur de Jong
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, 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 St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "daemon.h"
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
int daemon(int nochdir,int noclose)
{
/* change directory */
if (!nochdir)
if (chdir("/")!=0)
return -1;
/* fork() and exit() to detach from the parent process */
switch (fork())
{
case 0: /* we are the child */
break;
case -1: /* we are the parent, but have an error */
return -1;
default: /* we are the parent and we're done*/
_exit(0);
}
/* become process leader */
if (setsid()<0)
{
return -1;
}
/* fork again so we cannot allocate a pty */
switch (fork())
{
case 0: /* we are the child */
break;
case -1: /* we are the parent, but have an error */
return -1;
default: /* we are the parent and we're done*/
_exit(0);
}
/* close stdin, stdout and stderr and reconnect to /dev/null */
if (!noclose)
{
close(0); /* stdin */
close(1); /* stdout */
close(2); /* stderr */
open("/dev/null",O_RDWR); /* stdin, fd=0 */
dup(0); /* stdout, fd=1 */
dup(0); /* stderr, fd=2 */
}
return 0;
}
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