test_sem_permission.cpp

#include <iostream>
#include <sys/stat.h>
#include <sys/sem.h>
#include <stdio.h>
#include <stdlib.h>
#include <semaphore.h>
#include <errno.h>
#include <fcntl.h>

int main()
{
 std::cout << "hello world" << std::endl;

  sem_t *mySem;

  mySem = sem_open("/name1", O_CREAT | O_EXCL, 0666, 2);

  if (mySem == SEM_FAILED)
  {
 /* Check the error value */
 
   if (errno == EACCES)
   {
   /* Permission is denied */
   printf("Error: EACCESS Permission denied\n");
   }
   else
   {
   /* Show the other error */
   printf("Some other error");
   /* return; */
   }
  }
  else
  {
  /* Process created the semaphore */
  int a1;
  sem_wait(mySem);
  printf("Sample data written\n");
  sem_getvalue(mySem, &a1);
  printf("Value of mySem=%d \n", a1);
  sem_unlink("/name1");
  sem_close(mySem);
  exit(0);
  }
}