linux: Inter-Process Communication

The types of inter process communication are:

1. Signals - Sent by other processes or the kernel to a specific process to indicate various conditions.
2. Pipes - Unnamed pipes set up by the shell normally with the "|" character to route output from one program to the input of another.
3. FIFOS - Named pipes operating on the basis of first data in, first data out.
4. Message queues - Message queues are a mechanism set up to allow one or more processes to write messages that can be read by one or more other processes.
5. Semaphores - Counters that are used to control access to shared resources. These counters are used as a locking mechanism to prevent more than one process from using the resource at a time.
6. Shared memory - The mapping of a memory area to be shared by multiple processes.