52 lines
1.5 KiB
Go
52 lines
1.5 KiB
Go
// Sometimes we'd like our Go programs to intelligently
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// handle [Unix signals](https://en.wikipedia.org/wiki/Unix_signal).
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// For example, we might want a server to gracefully
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// shutdown when it receives a `SIGTERM`, or a command-line
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// tool to stop processing input if it receives a `SIGINT`.
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// Here's how to handle signals in Go with channels.
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package main
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import (
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"fmt"
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"os"
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"os/signal"
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"syscall"
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)
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func main() {
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// Go signal notification works by sending `os.Signal`
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// values on a channel. We'll create a channel to
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// receive these notifications. Note that this channel
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// should be buffered.
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sigs := make(chan os.Signal, 1)
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// `signal.Notify` registers the given channel to
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// receive notifications of the specified signals.
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signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
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// We could receive from `sigs` here in the main
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// function, but let's see how this could also be
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// done in a separate goroutine, to demonstrate
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// a more realistic scenario of graceful shutdown.
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done := make(chan bool, 1)
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go func() {
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// This goroutine executes a blocking receive for
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// signals. When it gets one it'll print it out
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// and then notify the program that it can finish.
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sig := <-sigs
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fmt.Println()
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fmt.Println(sig)
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done <- true
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}()
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// The program will wait here until it gets the
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// expected signal (as indicated by the goroutine
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// above sending a value on `done`) and then exit.
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fmt.Println("awaiting signal")
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<-done
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fmt.Println("exiting")
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}
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