/*
 * ISA 563, Spring 2011
 * Copyleft by Muhammad Abdulla
 */

#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>
#include <stdlib.h>

/*
 * simple_daemon.c -- demonstrates basic steps to daemonize a program
 */

int daemonize()
{
   pid_t pid;

   if ( (pid = fork()) < 0 ) {   // fork error
      return -1;
   } else if ( pid != 0 ) {      // parent should exit
      exit(0);
   }

   // child continues from here on

   // become a session leader
   setsid();

   // change working directory to / 
   chdir("/");

   // clear out file creation masks
   umask(0);

   return 0;
}

int main(int argc, char *argv[])
{
   daemonize();

   // do some hard work in the background
   while(1) {
      sleep(1);
   }
}