07-30-2013
There are quite a few things wrong with both the reader and writer programs...however the one thing that jumps out is that both the read and write calls expect a pointer as their 2nd argument...while you are providing an int** pointer...so once the 2nd argument to read and write is made an int* type then it should work...
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Dear Reader,
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IPC(2) Linux Programmer's Manual IPC(2)
NAME
ipc - System V IPC system calls
SYNOPSIS
int ipc(unsigned int call, int first, int second, int third, void *ptr, long fifth);
DESCRIPTION
ipc() is a common kernel entry point for the System V IPC calls for messages, semaphores, and shared memory. call determines which IPC
function to invoke; the other arguments are passed through to the appropriate call.
User programs should call the appropriate functions by their usual names. Only standard library implementors and kernel hackers need to
know about ipc().
CONFORMING TO
ipc() is Linux specific, and should not be used in programs intended to be portable.
SEE ALSO
msgctl(2), msgget(2), msgrcv(2), msgsnd(2), semctl(2), semget(2), semop(2), shmat(2), shmctl(2), shmdt(2), shmget(2)
Linux 1.2.4 1995-04-15 IPC(2)