go-daemon/c-daemon/daemon/daemon.c

#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <linux/fs.h>
#include <linux/limits.h>
#define NR_OPEN 1024

int _daemon(int nochdir, int noclose){
  pid_t pid, sid; 
  // pid_t defined in sys/types.h
  // pid_t is a signed int data type
  pid = fork(); // fork of the parent process 
  // fork() function defined in unistd.h
  if (pid < 0){
    exit(EXIT_FAILURE); // exit and  EXIT_FAILURE defined in stdlib.h
  }
  else if (pid > 0){
    exit(EXIT_SUCCESS);
  } 
  // sid = setsid();
  // if (sid < 0) {
  //   exit(EXIT_FAILURE);
  // }
  // if ((chdir("/")) < 0) {
  //   exit(EXIT_FAILURE);
  // }
  // if (!noclose) {
  //   for (int i = 0; i < NR_OPEN; i++)
  //     close(i);
  //   open("/dev/null", O_RDWR);
  //   dup(0);
  //   dup(0);
  // }
  // close(STDOUT_FILENO);
  // close(STDERR_FILENO);
  while (1) {
    int status = system("./info");
    // TODO SECURITY ISSUE
    // LINK https://stackoverflow.com/questions/5237482/how-do-i-execute-an-external-program-within-c-code-in-linux-with-arguments#
    

    sleep(1);
  }
  exit(EXIT_SUCCESS);
}