ipc:sysv:message-queue:create and send

ftok() creates a SYS V IPC key
msgget() creates/access a message queue, returns qid
struct mymsgbuf: the message data
msgsnd() sends out the message
ipc:sysv:message-queue:receive, msgctl

msgrcv()
msgctl(): IPC_STAT, IPC_SET, IPC_RMID