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/* $Id: daemon.c,v 1.3 2004-08-10 21:24:23 rjkaes Exp $
*
* This file contains functions which are useful when writing a
* daemon process. The functions include a "makedaemon" function and
* a function to portably set a signal handler.
*
* Copyright (C) 2002 Robert James Kaes (rjkaes@flarenet.com)
*
* 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.
*/
#include "tinyproxy.h"
#include "daemon.h"
/*
* Fork a child process and then kill the parent so make the calling
* program a daemon process.
*/
void
makedaemon(void)
{
if (fork() != 0)
exit(0);
setsid();
set_signal_handler(SIGHUP, SIG_IGN);
if (fork() != 0)
exit(0);
chdir("/");
umask(077);
#if NDEBUG
/*
* When not in debugging mode, close the standard file
* descriptors.
*/
close(0);
close(1);
close(2);
#endif
}
/*
* Pass a signal number and a signal handling function into this function
* to handle signals sent to the process.
*/
signal_func *
set_signal_handler(int signo, signal_func *func)
{
struct sigaction act, oact;
act.sa_handler = func;
sigemptyset(&act.sa_mask);
act.sa_flags = 0;
if (signo == SIGALRM) {
#ifdef SA_INTERRUPT
act.sa_flags |= SA_INTERRUPT; /* SunOS 4.x */
#endif
} else {
#ifdef SA_RESTART
act.sa_flags |= SA_RESTART; /* SVR4, 4.4BSD */
#endif
}
if (sigaction(signo, &act, &oact) < 0)
return SIG_ERR;
return oact.sa_handler;
}
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