What interprocess communication (IPC) methods exist in Linux? How do SIGTERM and SIGKILL differ?

In Linux, there are various methods of interprocess communication (IPC):

• Pipes — allow data transfer between processes related by parent-child relationships.
• Named Pipes (FIFO) — similar to pipes but have a name in the filesystem and can be used between any processes.
• Sockets — enable data exchange between processes on the same or different hosts.
• Shared Memory — allocates a memory area accessible by multiple processes for fast data transfer.
• Semaphores — used for synchronizing access to resources.
• Message Queues — allow sending and receiving structured messages.
• Signals — asynchronous notifications about events.

Difference between SIGTERM and SIGKILL:

• SIGTERM (15) — a signal requesting process termination. The process can catch this signal, perform cleanup, and terminate gracefully. It is a "polite" way to stop a process.

• SIGKILL (9) — a signal for immediate process termination, which cannot be caught or ignored. The process is forcibly terminated without cleanup.

In Go, the os/signal package is used to handle signals, allowing catching and processing signals, for example:

import (
    "os"
    "os/signal"
    "syscall"
    "fmt"
)

func main() {
    sigs := make(chan os.Signal, 1)
    signal.Notify(sigs, syscall.SIGTERM, syscall.SIGINT)

    sig := <-sigs
    fmt.Println("Received signal:", sig)
    // Cleanup actions can be performed here before exit
}