// Copyright (C) 2021 Marius Schellenberger

package scan

import (
	"fmt"
	"os/exec"
	"time"
)

func timeout(cmd *exec.Cmd, t time.Duration) (output []byte, err error) {
	done := make(chan error)
	out := make(chan []byte)
	go func() {
		o, e := cmd.Output()
		done <- e
		out <- o
	}()
	select {
	case <-time.After(t):
		e := cmd.Process.Kill()
		err = <-done
		<-out
		if e != nil {
			err = e
		} else {
			err = fmt.Errorf("command '%s' timed out: %s", cmd.Path, err)
		}
	case e := <-done:
		exerr, ok := e.(*exec.ExitError)
		if ok {
			err = fmt.Errorf("%s\n%s", e, string(exerr.Stderr))
		} else {
			err = e
		}
		output = <-out
	}
	return
}