go-daemon/c-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>

int _daemon(int nochdir, int noclose){
  pid_t pid; 
  // 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_FAILURE);
  } 
  if (setsid() == -1){
    return -1;
  }
  return 0;
}