turn-off coloring if we have std{err,out} dumb terminals (#19667)

cmd/common-main.go

@@ -63,6 +63,7 @@ import (
 	"github.com/minio/pkg/v2/ellipses"
 	"github.com/minio/pkg/v2/env"
 	xnet "github.com/minio/pkg/v2/net"
+	"golang.org/x/term"
 )
 
 // serverDebugLog will enable debug printing
@@ -73,6 +74,13 @@ var (
 )
 
 func init() {
+	if !term.IsTerminal(int(os.Stdout.Fd())) || !term.IsTerminal(int(os.Stderr.Fd())) {
+		color.TurnOff()
+	}
+	if env.Get("NO_COLOR", "") != "" || env.Get("TERM", "") == "dumb" {
+		color.TurnOff()
+	}
+
 	if runtime.GOOS == "windows" {
 		if mousetrap.StartedByExplorer() {
 			fmt.Printf("Don't double-click %s\n", os.Args[0])

go.mod

@@ -95,6 +95,7 @@ require (
 	golang.org/x/exp v0.0.0-20240416160154-fe59bbe5cc7f
 	golang.org/x/oauth2 v0.19.0
 	golang.org/x/sys v0.19.0
+	golang.org/x/term v0.19.0
 	golang.org/x/time v0.5.0
 	google.golang.org/api v0.172.0
 	gopkg.in/yaml.v2 v2.4.0
@@ -241,7 +242,6 @@ require (
 	golang.org/x/mod v0.17.0 // indirect
 	golang.org/x/net v0.24.0 // indirect
 	golang.org/x/sync v0.7.0 // indirect
-	golang.org/x/term v0.19.0 // indirect
 	golang.org/x/text v0.14.0 // indirect
 	golang.org/x/tools v0.20.0 // indirect
 	google.golang.org/genproto v0.0.0-20240415180920-8c6c420018be // indirect

internal/logger/logger.go

@@ -80,6 +80,7 @@ var (
 
 // EnableQuiet - turns quiet option on.
 func EnableQuiet() {
+	color.TurnOff() // no colored outputs necessary in quiet mode.
 	quietFlag = true
 }