Auto-disable color coding when piped

pkg/color/coloring.go

@@ -2,6 +2,7 @@ package color
 
 import (
 	"fmt"
+	"os"
 	"strings"
 )
 
@@ -34,12 +35,21 @@ const (
 
 // Enabled controls whether or not coloring is applied
 var Disabled = false
+var forceDisable = false
 
 var groupColors = [...]ColorCode{Red, Green, Yellow, Blue, Magenta, Cyan}
 
+func init() {
+	if fi, err := os.Stdout.Stat(); err == nil {
+		if (fi.Mode() & os.ModeCharDevice) == 0 {
+			forceDisable = true
+		}
+	}
+}
+
 // Wrap surroungs a string with a color (if enabled)
 func Wrap(color ColorCode, s string) string {
-	if Disabled {
+	if Disabled || forceDisable {
 		return s
 	}
 
@@ -64,7 +74,7 @@ func Wrapi(color ColorCode, s interface{}) string {
 // WrapIndices color-codes by group pairs (regex-style)
 //  [aStart, aEnd, bStart, bEnd...]
 func WrapIndices(s string, groups []int) string {
-	if Disabled {
+	if Disabled || forceDisable {
 		return s
 	}
 	if len(groups) == 0 || len(groups)%2 != 0 {