为什么一些posix共享内存段和posix信号量对ipcs不可见

I built a client server application using posix shared memory and posix unnamed semaphores with pshared=1. The semaphores are placed inside the shared memory. The program runs fine, but when I type ipcs -m or ipcs -s, I do not see any shared memory segments or semaphores that I created. Why is it so?I built a client server application using posix