~drizzle-trunk/drizzle/development

/*    $Header: /cvsroot/wikipedia/willow/src/bin/willow/daemon.c,v 1.1 2005/05/02 19:15:21 kateturner Exp $    */

/*    $NetBSD: daemon.c,v 1.9 2003/08/07 16:42:46 agc Exp $    */

/*-

 * Copyright (c) 1990, 1993

 *    The Regents of the University of California.  All rights reserved.

 * Copyright (c) 2010

 *    Stewart Smith

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. Neither the name of the University nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 */

#include <config.h>

#if defined __SUNPRO_C || defined __DECC || defined __HP_cc

# pragma ident "@(#)$Header: /cvsroot/wikipedia/willow/src/bin/willow/daemon.c,v 1.1 2005/05/02 19:15:21 kateturner Exp $"

# pragma ident "$NetBSD: daemon.c,v 1.9 2003/08/07 16:42:46 agc Exp $"

#endif

#include <fcntl.h>

#include <stdio.h>

#include <stdlib.h>

#include <sys/types.h>

#include <sys/wait.h>

#include <signal.h>

#include <unistd.h>

#include <sys/select.h>

#include <drizzled/daemon.h>

namespace drizzled

{

pid_t parent_pid;

extern "C"

{

static void sigusr1_handler(int sig)

{

  if (sig == SIGUSR1)

    _exit(EXIT_SUCCESS);

}

}

void daemon_is_ready()

{

  int fd;

  kill(parent_pid, SIGUSR1);

  if ((fd = open("/dev/null", O_RDWR, 0)) != -1) 

  {

    if(dup2(fd, STDIN_FILENO) < 0)

    {

      perror("dup2 stdin");

      return;

    }

    if(dup2(fd, STDOUT_FILENO) < 0)

    {

      perror("dup2 stdout");

      return;

    }

    if(dup2(fd, STDERR_FILENO) < 0)

    {

      perror("dup2 stderr");

      return;

    }

    if (fd > STDERR_FILENO)

    {

      if (close(fd) < 0)

      {

        perror("close");

        return;

      }

    }

  }

}

bool daemonize()

{

  pid_t child= -1;

  parent_pid= getpid();

  signal(SIGUSR1, sigusr1_handler);

  child= fork();

  switch (child)

  {

  case -1:

    return true;

  case 0:

    break;

  default:

    {

      /* parent */

      int exit_code= -1;

      int status;

      while (waitpid(child, &status, 0) != child)

      { }

      if (WIFEXITED(status))

      {

        exit_code= WEXITSTATUS(status);

      }

      if (WIFSIGNALED(status))

      {

        exit_code= -1;

      }

      _exit(exit_code);

    }

  }

  /* child */

  if (setsid() == -1)

  {

    return true;

  }

  return false; 

}

} /* namespace drizzled */