The ipcrm Command

The ipcrm command can be used to remove an IPC object from the kernel. While IPC objects can be removed via system calls in user code (we'll see how in a moment), the need often arises, especially under development environments, to remove IPC objects manually. Its usage is simple:

ipcrm <msg | sem | shm>  <IPC ID>

Simply specify whether the object to be deleted is a message queue (msg), a semaphore set (sem), or a shared memory segment (shm). The IPC ID can be obtained by the ipcs command. You have to specify the type of object, since identifiers are unique among the same type (recall our discussion of this earlier).