Can processes communicate with each other? What IPC (inter-process communication) methods exist?

Yes, processes can communicate with each other. Inter-process communication (IPC) is a set of methods for exchanging data between different processes.

Main IPC methods:

• Pipes: Unidirectional or bidirectional byte streams between processes.
• Sockets: Network connections, which can work locally (Unix domain sockets) or over a network (TCP/UDP).
• Shared memory: Allocating a memory area accessible by multiple processes.
• Semaphores and mutexes: For synchronizing access to resources.
• Message queues: Queues for exchanging messages.
• Files: Processes can read from and write to files for communication.

In Go, IPC is often implemented using:

• Unix domain sockets: via the net package
• Channels and goroutines: within a single process
• RPC calls: via net/rpc or gRPC for inter-process communication

Example of using Unix domain socket:

listener, _ := net.Listen("unix", "/tmp/socket")
conn, _ := listener.Accept()
// read/write to conn

Thus, the choice of IPC method depends on the requirements for performance, reliability, and application architecture.