@@ -214,11 +214,16 @@ func downloadcmd(opt Options) error {
 		return fmt.Errorf("github did not respond with 200 OK but with %v", resp.Status)
 	}
 
-	out, err := os.Create(name)
-	if err != nil {
-		return fmt.Errorf("could not create file %s", name)
+	out := os.Stdout // Pipe the asset to stdout by default.
+	if isCharDevice(out) {
+		// If stdout is a char device, assume it's a TTY (terminal). In this
+		// case, don't pipe th easset to stdout, but create it as a file in
+		// the current working folder.
+		if out, err = os.Create(name); err != nil {
+			return fmt.Errorf("could not create file %s", name)
+		}
+		defer out.Close()
 	}
-	defer out.Close()
 
 	n, err := io.Copy(out, resp.Body)
 	if n != contentLength {
 
@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"os"
 	"time"
 )
 
@@ -18,15 +19,15 @@ func nvls(xs ...string) string {
 
 func vprintln(a ...interface{}) (int, error) {
 	if VERBOSITY > 0 {
-		return fmt.Println(a...)
+		return fmt.Fprintln(os.Stderr, a...)
 	}
 
 	return 0, nil
 }
 
 func vprintf(format string, a ...interface{}) (int, error) {
 	if VERBOSITY > 0 {
-		return fmt.Printf(format, a...)
+		return fmt.Fprintf(os.Stderr, format, a...)
 	}
 
 	return 0, nil
@@ -39,3 +40,13 @@ func timeFmtOr(t *time.Time, fmt, def string) string {
 	}
 	return t.Format(fmt)
 }
+
+// isCharDevice returns true if f is a character device (panics if f can't
+// be stat'ed).
+func isCharDevice(f *os.File) bool {
+	stat, err := f.Stat()
+	if err != nil {
+		panic(err)
+	}
+	return (stat.Mode() & os.ModeCharDevice) != 0
+}
Original file line number	Diff line number	Diff line change
@@ -2,6 +2,7 @@ package main
2	2
3	3	import (
4	4	"fmt"
	5	+ "os"
5	6	"time"
6	7	)
7	8
@@ -18,15 +19,15 @@ func nvls(xs ...string) string {
18	19
19	20	func vprintln(a ...interface{}) (int, error) {
20	21	if VERBOSITY > 0 {
21		- return fmt.Println(a...)
	22	+ return fmt.Fprintln(os.Stderr, a...)
22	23	}
23	24
24	25	return 0, nil
25	26	}
26	27
27	28	func vprintf(format string, a ...interface{}) (int, error) {
28	29	if VERBOSITY > 0 {
29		- return fmt.Printf(format, a...)
	30	+ return fmt.Fprintf(os.Stderr, format, a...)
30	31	}
31	32
32	33	return 0, nil
@@ -39,3 +40,13 @@ func timeFmtOr(t *time.Time, fmt, def string) string {
39	40	}
40	41	return t.Format(fmt)
41	42	}
	43	+
	44	+ // isCharDevice returns true if f is a character device (panics if f can't
	45	+ // be stat'ed).
	46	+ func isCharDevice(f *os.File) bool {
	47	+ stat, err := f.Stat()
	48	+ if err != nil {
	49	+ panic(err)
	50	+ }
	51	+ return (stat.Mode() & os.ModeCharDevice) != 0
	52	+ }