# Signals

The provided Go code demonstrates how to handle signals such as `SIGINT` and `SIGTERM` in a Go program using channels and goroutines. Here's a breakdown of the code:

```go
package main

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

func main() {
	// Create a channel to receive signals.
	sigs := make(chan os.Signal, 1)

	// Notify the program to listen for SIGINT and SIGTERM signals.
	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)

	// Create a channel to signal when the program is done.
	done := make(chan bool, 1)

	// Start a goroutine to handle signals.
	go func() {
		// Wait for a signal to be received on the 'sigs' channel.
		sig := <-sigs
		fmt.Println()
		fmt.Println(sig)
		// Signal that the program is done.
		done <- true
	}()

	fmt.Println("awaiting signal")

	// Wait for the program to be done (signal received).
	<-done
	fmt.Println("exiting")
}
```

Explanation:

1. `sigs := make(chan os.Signal, 1)`: Creates a buffered channel (`sigs`) to receive signals. The buffer size is set to 1 to avoid missing signals if multiple signals arrive quickly.
2. `signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)`: Notifies the program to listen for `SIGINT` (Ctrl+C) and `SIGTERM` (termination request) signals. When a signal is received, it will be sent to the `sigs` channel.
3. `done := make(chan bool, 1)`: Creates a buffered channel (`done`) to signal when the program is done.
4. `go func() { ... }()`: Starts a goroutine to handle signals. Inside the goroutine, it waits for a signal on the `sigs` channel, prints the received signal, and signals that the program is done by sending a value to the `done` channel.
5. `fmt.Println("awaiting signal")`: Prints a message indicating that the program is waiting for a signal.
6. `<-done`: Waits for the program to be done (signal received) by receiving a value from the `done` channel.
7. `fmt.Println("exiting")`: Prints a message indicating that the program is exiting.

This code allows the program to gracefully handle termination signals and perform necessary cleanup before exiting.