#include <iostream>
#include <sys/types.h>
#include <sys/sem.h>
#include <sys/ipc.h>
#include <errno.h>
#include "err.h"

using namespace std;
 
int main ()
{
  key_t key;
  int opperm, flags, nsems, semid, opperm_flag;

  cout << "Enter the desired key = " << endl;
  cin >> key;

  cout << "Enter the operation permissions in octal = ";
  cin.unsetf(ios::dec);
  cin.setf(ios::oct);
  cin >> opperm;
  cin.unsetf(ios::oct);
  cin.setf(ios::dec);
  cout << endl;

  cout << "Enter corresponding number to set desired flags:" << endl;
  cout << "0 --> No flags" << endl;
  cout << "1 --> IPC_CREAT" << endl;
  cout << "2 --> IPC_EXCL" << endl;
  cout << "3 --> IPC_CREAT and IPC_EXCL" << endl;
  cout << "Flags = ";
  cin >> flags;
  cout << endl;

  cout << "key = " << key << " opperm = ";
  cin.unsetf(ios::dec);
  cout.setf(ios::oct);
  cout << opperm;
  cin.unsetf(ios::oct);
  cout.setf(ios::dec);
  cout << " flags = " << flags << endl;

  switch ( flags ) {
    case 0:
      opperm_flag = opperm | 0;
      break;
    case 1:
      opperm_flag = opperm | IPC_CREAT;
      break;
    case 2:
      opperm_flag = opperm | IPC_EXCL;
      break;
    case 3:
      opperm_flag = opperm | IPC_EXCL | IPC_CREAT;
      break;
  }
  
  cout << "Enter the number of desired semaphores for this set (25 max) = ";
  cin >> nsems;
  cout << endl;
  cout << "Nsems = " << nsems << endl;

  /*********************************************************/

  semid = semget( key, nsems, opperm_flag );

  /*********************************************************/

  if ( semid == -1 ) syserr("semget");
  
  cout << "The semid = " << semid << endl;
  return 0;
}