hnakra/daemon/daemon.go
2023-05-31 18:07:06 -04:00

51 lines
1.3 KiB
Go

// Package daemon provides utilities for daemons.
package daemon
import "io"
import "os"
import "syscall"
import "strconv"
import "os/signal"
// PidFile is a string that contains a path to a pidfile.
type PidFile string
// Start writes to the pidfile.
func (pidfile PidFile) Start () error {
return os.WriteFile(string(pidfile), []byte(strconv.Itoa(os.Getpid())), 0644)
}
// Close deletes the pidfile.
func (pidfile PidFile) Close () error {
return os.Remove(string(pidfile))
}
// Empty returns true if the object is zero value (an empty string).
func (pidfile PidFile) Empty () bool {
return pidfile == ""
}
// OnSigint calls the specified function once sigint is recieved. This function
// does not block, and spawns a goroutine that waits. For this reason, the
// callback must be safe to call concurrently.
func OnSigint (callback func ()) {
go func () {
sigintNotify := make(chan os.Signal, 1)
signal.Notify(sigintNotify, os.Interrupt, syscall.SIGTERM)
<-sigintNotify
callback()
} ()
}
// CloseOnSigint is like OnSigint, but takes an io.Closer.
func CloseOnSigint (closer io.Closer) {
OnSigint(func () { closer.Close() })
}
// ShutdownOnSigint is like OnSigint, but takes an object with a Shutdown()
// method.
func ShutdownOnSigint (shutdowner interface { Shutdown() error }) {
OnSigint(func () { shutdowner.Shutdown() })
}