/*
 * static char *rcsid_deamon_c =
 *   "$Id: daemon.c,v 1.10 1997/03/09 05:07:54 master Exp $";
 */

/*
 * BecomeDaemon.c
 * shamelessly swiped from xdm source code.
 * Appropriate copyrights kept, and hereby follow
 * ERic mehlhaff, 3/11/92
 *
 * xdm - display manager daemon
 *
 * $XConsortium: daemon.c,v 1.5 89/01/20 10:43:49 jim Exp $
 *
 * Copyright 1988 Massachusetts Institute of Technology
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose and without fee is hereby granted, provided
 * that the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of M.I.T. not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  M.I.T. makes no representations about the
 * suitability of this software for any purpose.  It is provided "as is"
 * without express or implied warranty.
 *
 * Author:  Keith Packard, MIT X Consortium
 */


#include <global.h>
#include <sys/ioctl.h>
#ifdef hpux
#include <sys/ptyio.h>
#endif

#include <errno.h>
#include <stdio.h>
#include <sys/file.h>

FILE *BecomeDaemon (char *filename)
{
#ifdef SERVER
  FILE *logfile;
  register int i;
  int forkresult;
 
  if((logfile=fopen(filename,"a"))==NULL){
    printf("Couldn't create logfile %s.\n",filename);
    exit(0);
  } 
  fputs("\n========================\n",logfile);    
  fputs("Begin New Server Session\n",logfile);    
  fputs("========================\n\n",logfile);    
  fflush(logfile);
    /*
     * fork so that the process goes into the background automatically. Also
     * has a nice side effect of having the child process get inherited by
     * init (pid 1).
     */

    if ( (forkresult = fork ()) ){	/* if parent */
	  if(forkresult < 0 ){
		perror("Fork error!");
	  }
	  exit (0);			/* then no more work to do */
      }

    /*
     * Close standard file descriptors and get rid of controlling tty
     */

    close (0); 
    close (1);
    close (2);

    /*
     * Set up the standard file descriptors.
     */
    (void) open ("/", O_RDONLY);	/* root inode already in core */
    (void) dup2 (0, 1);
    (void) dup2 (0, 2);

    if ((i = open ("/dev/tty", O_RDWR)) >= 0) {	/* did open succeed? */
#if defined(SYSV) && defined(TIOCTTY)
	int zero = 0;
	(void) ioctl (i, TIOCTTY, &zero);
#else
#ifndef TIOCNOTTY /********* !!!!!!!!! **********/
#if defined(SVR4)
#include <sys/termios.h>
#else
#include <sys/ttycom.h>
#endif
#endif
	(void) ioctl (i, TIOCNOTTY, (char *) 0);    /* detach, BSD style */
#endif
	(void) close (i);
    }


#if defined(SYSV) || defined(SVR4)
#if defined(__sun__) || defined(hpux) || defined(sgi) || defined(__osf__)
    setsid();
#else
    setpgrp (0, 0);
#endif
#else /* Non SYSV machines */
#if defined(__osf__) || defined(linux)
    setsid();
#else
    setpgrp (0, getpid());
#endif
#endif
  return(logfile);
#else
  return (NULL);
#endif
}
