gnb_daemon.c

/*
   Copyright (C) gnbdev

   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 3 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, see <http://www.gnu.org/licenses/>.
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "gnb_platform.h"

#ifdef __UNIX_LIKE_OS__

#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#endif


#ifdef __UNIX_LIKE_OS__

int gnb_daemon(){

  int ret;

  int fd;

  pid_t pid;

  pid = fork();

  if ( 0 != pid ) {
      exit(0);
  }

  setsid();

  signal(SIGHUP,SIG_IGN);

  pid = fork();

  if ( 0 != pid ) {
      exit(0);
  }

  ret = chdir("/");

  umask(0);

  fd = open("/dev/null", O_RDWR);

  if ( -1 == fd ) {
      return -1;
  }

  ret = dup2(fd, STDIN_FILENO);

  if ( -1 == ret ) {
      return -2;
  }

  ret = dup2(fd, STDOUT_FILENO);

  if ( -1 == ret ) {
      return -3;
  }

  return 0;

}


void save_pid(const char *pid_file){

    FILE *file;

    file = fopen(pid_file,"w");

    if ( NULL==file ) {
        printf("open pid file[%s] err\n",pid_file);
        exit(1);
    }

    int pid = getpid();

    fprintf(file,"%d",pid);

    fclose(file);

}

#endif