Handling Unix Signals in Go Programs

Introduction

The Signals challenge demonstrates how to handle Unix signals in Go programs using channels.

Skills Graph

%%%%{init: {'theme':'neutral'}}%%%% flowchart RL go(("`Go`")) -.-> go/NetworkingGroup(["`Networking`"]) go/NetworkingGroup -.-> go/signals("`Signals`") subgraph Lab Skills go/signals -.-> lab-15425{{"`Handling Unix Signals in Go Programs`"}} end

Signals

In some cases, we want our Go programs to handle Unix signals intelligently. For instance, we might want a server to shut down gracefully when it receives a SIGTERM, or a command-line tool to stop processing input if it receives a SIGINT.

Requirements

Create a buffered channel to receive os.Signal notifications.
Register the channel to receive notifications of specified signals using signal.Notify.
Create a goroutine to execute a blocking receive for signals.
Print out the received signal and notify the program that it can finish.
Wait for the expected signal and then exit.

Example

## When we run this program it will block waiting for a
## signal. By typing `ctrl-C` (which the
## terminal shows as `^C`) we can send a `SIGINT` signal,
## causing the program to print `interrupt` and then exit.
$ go run signals.go
awaiting signal
^C
interrupt
exiting

Summary

The Signals challenge demonstrates how to handle Unix signals in Go programs using channels. By creating a buffered channel to receive os.Signal notifications and registering the channel to receive notifications of specified signals using signal.Notify, we can gracefully handle signals and exit the program when the expected signal is received.