// This creates a simple hello world window package main import ( "log" "fmt" "os" "io" "time" "bufio" arg "github.com/alexflint/go-arg" ) var args struct { Foo string Bar bool User string `arg:"env:USER"` Demo bool `help:"run a demo"` } var f1 *os.File var f2 *os.File var err error func init() { arg.MustParse(&args) fmt.Println(args.Foo, args.Bar, args.User) f1, err = os.OpenFile("/tmp/guilogfile", os.O_RDWR | os.O_CREATE | os.O_APPEND, 0666) if err != nil { log.Fatalf("error opening file: %v", err) } // hmm. is there a trick here or must this be in main() // defer f.Close() log.SetOutput(f1) log.Println("This is a test log entry") } func captureSTDOUT() { f2, _ = os.OpenFile("/tmp/my.log", os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0664) multiWriter := io.MultiWriter(os.Stderr, f2) rd, wr, err := os.Pipe() if err != nil { os.Exit(1) } // overwrite os.Stdout os.Stderr = wr go func() { scanner := bufio.NewScanner(rd) for scanner.Scan() { stdoutLine := scanner.Text() multiWriter.Write([]byte(stdoutLine + "\n")) } }() fmt.Println("foobar") // hacky sleep to ensure the go routine can write before program exits time.Sleep(time.Second) }