// getIsExternal finds a set of all external commands and puts it on the result // channel. func getIsExternal(ev *eval.Evaler, result chan<- map[string]bool) { names := make(chan string, 32) go func() { ev.AllExecutables(names) close(names) }() isExternal := make(map[string]bool) for name := range names { isExternal[name] = true } result <- isExternal }