Merge 9d4b134da1 into 283e32d889

.gitignore

@@ -19,6 +19,9 @@ _cgo_export.*
 
 _testmain.go
 
+# Translation files
+translations/translate.*.toml
+
 # Vim files https://github.com/github/gitignore/blob/master/Global/Vim.gitignore
 # swap
 [._]*.s[a-w][a-z]

Makefile

@@ -33,3 +33,12 @@ install_deps:
 
 clean:
 	rm -rf $(BIN)
+
+i18n_extract:
+	$(info ******************** extracting translation files ********************)
+	goi18n extract -outdir translations
+	goi18n merge -outdir translations translations/*
+
+i18n_merge:
+	$(info ******************** merging translation files ********************)
+	goi18n merge -outdir translations translations/*

args.go

@@ -33,7 +33,7 @@ func legacyArgs(cmd *Command, args []string) error {
 
 	// root command with subcommands, do subcommand checking.
 	if !cmd.HasParent() && len(args) > 0 {
-		return fmt.Errorf("unknown command %q for %q%s", args[0], cmd.CommandPath(), cmd.findSuggestions(args[0]))
+		return fmt.Errorf(i18nLegacyArgsValidationError(), args[0], cmd.CommandPath(), cmd.findSuggestions(args[0]))
 	}
 	return nil
 }
@@ -41,7 +41,7 @@ func legacyArgs(cmd *Command, args []string) error {
 // NoArgs returns an error if any args are included.
 func NoArgs(cmd *Command, args []string) error {
 	if len(args) > 0 {
-		return fmt.Errorf("unknown command %q for %q", args[0], cmd.CommandPath())
+		return fmt.Errorf(i18nNoArgsValidationError(), args[0], cmd.CommandPath())
 	}
 	return nil
 }
@@ -58,7 +58,7 @@ func OnlyValidArgs(cmd *Command, args []string) error {
 		}
 		for _, v := range args {
 			if !stringInSlice(v, validArgs) {
-				return fmt.Errorf("invalid argument %q for %q%s", v, cmd.CommandPath(), cmd.findSuggestions(args[0]))
+				return fmt.Errorf(i18nOnlyValidArgsValidationError(), v, cmd.CommandPath(), cmd.findSuggestions(args[0]))
 			}
 		}
 	}
@@ -74,7 +74,7 @@ func ArbitraryArgs(cmd *Command, args []string) error {
 func MinimumNArgs(n int) PositionalArgs {
 	return func(cmd *Command, args []string) error {
 		if len(args) < n {
-			return fmt.Errorf("requires at least %d arg(s), only received %d", n, len(args))
+			return fmt.Errorf(i18nMinimumNArgsValidationError(n), n, len(args))
 		}
 		return nil
 	}
@@ -84,7 +84,7 @@ func MinimumNArgs(n int) PositionalArgs {
 func MaximumNArgs(n int) PositionalArgs {
 	return func(cmd *Command, args []string) error {
 		if len(args) > n {
-			return fmt.Errorf("accepts at most %d arg(s), received %d", n, len(args))
+			return fmt.Errorf(i18nMaximumNArgsValidationError(n), n, len(args))
 		}
 		return nil
 	}
@@ -94,7 +94,7 @@ func MaximumNArgs(n int) PositionalArgs {
 func ExactArgs(n int) PositionalArgs {
 	return func(cmd *Command, args []string) error {
 		if len(args) != n {
-			return fmt.Errorf("accepts %d arg(s), received %d", n, len(args))
+			return fmt.Errorf(i18nExactArgsValidationError(n), n, len(args))
 		}
 		return nil
 	}
@@ -104,7 +104,7 @@ func ExactArgs(n int) PositionalArgs {
 func RangeArgs(min int, max int) PositionalArgs {
 	return func(cmd *Command, args []string) error {
 		if len(args) < min || len(args) > max {
-			return fmt.Errorf("accepts between %d and %d arg(s), received %d", min, max, len(args))
+			return fmt.Errorf(i18nRangeArgsValidationError(max), min, max, len(args))
 		}
 		return nil
 	}

args_test.go

@@ -68,7 +68,7 @@ func minimumNArgsWithLessArgs(err error, t *testing.T) {
 		t.Fatal("Expected an error")
 	}
 	got := err.Error()
-	expected := "requires at least 2 arg(s), only received 1"
+	expected := "requires at least 2 args, only received 1"
 	if got != expected {
 		t.Fatalf("Expected %q, got %q", expected, got)
 	}
@@ -79,7 +79,7 @@ func maximumNArgsWithMoreArgs(err error, t *testing.T) {
 		t.Fatal("Expected an error")
 	}
 	got := err.Error()
-	expected := "accepts at most 2 arg(s), received 3"
+	expected := "accepts at most 2 args, received 3"
 	if got != expected {
 		t.Fatalf("Expected %q, got %q", expected, got)
 	}
@@ -90,7 +90,7 @@ func exactArgsWithInvalidCount(err error, t *testing.T) {
 		t.Fatal("Expected an error")
 	}
 	got := err.Error()
-	expected := "accepts 2 arg(s), received 3"
+	expected := "accepts 2 args, received 3"
 	if got != expected {
 		t.Fatalf("Expected %q, got %q", expected, got)
 	}
@@ -101,7 +101,7 @@ func rangeArgsWithInvalidCount(err error, t *testing.T) {
 		t.Fatal("Expected an error")
 	}
 	got := err.Error()
-	expected := "accepts between 2 and 4 arg(s), received 1"
+	expected := "accepts between 2 and 4 args, received 1"
 	if got != expected {
 		t.Fatalf("Expected %q, got %q", expected, got)
 	}

cobra.go

@@ -232,7 +232,7 @@ func stringInSlice(a string, list []string) bool {
 // CheckErr prints the msg with the prefix 'Error:' and exits with error code 1. If the msg is nil, it does nothing.
 func CheckErr(msg interface{}) {
 	if msg != nil {
-		fmt.Fprintln(os.Stderr, "Error:", msg)
+		fmt.Fprintln(os.Stderr, i18nError()+":", msg)
 		os.Exit(1)
 	}
 }

command.go

@@ -432,7 +432,11 @@ func (c *Command) UsageFunc() (f func(*Command) error) {
 	}
 	return func(c *Command) error {
 		c.mergePersistentFlags()
-		err := tmpl(c.OutOrStderr(), c.UsageTemplate(), c)
+		data := CommandUsageTemplateData{
+			Command: c,
+			I18n:    getCommandGlossary(),
+		}
+		err := tmpl(c.OutOrStderr(), c.UsageTemplate(), data)
 		if err != nil {
 			c.PrintErrln(err)
 		}
@@ -549,35 +553,35 @@ func (c *Command) UsageTemplate() string {
 	if c.HasParent() {
 		return c.parent.UsageTemplate()
 	}
-	return `Usage:{{if .Runnable}}
+	return `{{.I18n.SectionUsage}}:{{if .Runnable}}
   {{.UseLine}}{{end}}{{if .HasAvailableSubCommands}}
   {{.CommandPath}} [command]{{end}}{{if gt (len .Aliases) 0}}
 
-Aliases:
+{{.I18n.SectionAliases}}:
   {{.NameAndAliases}}{{end}}{{if .HasExample}}
 
-Examples:
+{{.I18n.SectionExamples}}:
 {{.Example}}{{end}}{{if .HasAvailableSubCommands}}{{$cmds := .Commands}}{{if eq (len .Groups) 0}}
 
-Available Commands:{{range $cmds}}{{if (or .IsAvailableCommand (eq .Name "help"))}}
+{{.I18n.SectionAvailableCommands}}:{{range $cmds}}{{if (or .IsAvailableCommand (eq .Name "help"))}}
   {{rpad .Name .NamePadding }} {{.Short}}{{end}}{{end}}{{else}}{{range $group := .Groups}}
 
 {{.Title}}{{range $cmds}}{{if (and (eq .GroupID $group.ID) (or .IsAvailableCommand (eq .Name "help")))}}
   {{rpad .Name .NamePadding }} {{.Short}}{{end}}{{end}}{{end}}{{if not .AllChildCommandsHaveGroup}}
 
-Additional Commands:{{range $cmds}}{{if (and (eq .GroupID "") (or .IsAvailableCommand (eq .Name "help")))}}
+{{.I18n.SectionAdditionalCommands}}:{{range $cmds}}{{if (and (eq .GroupID "") (or .IsAvailableCommand (eq .Name "help")))}}
   {{rpad .Name .NamePadding }} {{.Short}}{{end}}{{end}}{{end}}{{end}}{{end}}{{if .HasAvailableLocalFlags}}
 
-Flags:
+{{.I18n.SectionFlags}}:
 {{.LocalFlags.FlagUsages | trimTrailingWhitespaces}}{{end}}{{if .HasAvailableInheritedFlags}}
 
-Global Flags:
+{{.I18n.SectionGlobalFlags}}:
 {{.InheritedFlags.FlagUsages | trimTrailingWhitespaces}}{{end}}{{if .HasHelpSubCommands}}
 
-Additional help topics:{{range .Commands}}{{if .IsAdditionalHelpTopicCommand}}
+{{.I18n.SectionAdditionalHelpTopics}}:{{range .Commands}}{{if .IsAdditionalHelpTopicCommand}}
   {{rpad .CommandPath .CommandPathPadding}} {{.Short}}{{end}}{{end}}{{end}}{{if .HasAvailableSubCommands}}
 
-Use "{{.CommandPath}} [command] --help" for more information about a command.{{end}}
+{{.I18n.Use}} "{{.CommandPath}} [command] --help" {{.I18n.ForInfoAboutCommand}}.{{end}}
 `
 }
 
@@ -756,7 +760,7 @@ func (c *Command) findSuggestions(arg string) string {
 	}
 	suggestionsString := ""
 	if suggestions := c.SuggestionsFor(arg); len(suggestions) > 0 {
-		suggestionsString += "\n\nDid you mean this?\n"
+		suggestionsString += "\n\n" + i18nDidYouMeanThis() + "\n"
 		for _, s := range suggestions {
 			suggestionsString += fmt.Sprintf("\t%v\n", s)
 		}
@@ -877,7 +881,7 @@ func (c *Command) execute(a []string) (err error) {
 	}
 
 	if len(c.Deprecated) > 0 {
-		c.Printf("Command %q is deprecated, %s\n", c.Name(), c.Deprecated)
+		c.Printf(i18nCommandDeprecatedWarning()+"\n", c.Name(), c.Deprecated)
 	}
 
 	// initialize help and version flag at the last point possible to allow for user
@@ -1096,7 +1100,7 @@ func (c *Command) ExecuteC() (cmd *Command, err error) {
 		}
 		if !c.SilenceErrors {
 			c.PrintErrln(c.ErrPrefix(), err.Error())
-			c.PrintErrf("Run '%v --help' for usage.\n", c.CommandPath())
+			c.PrintErrf(i18nRunHelpTip()+"\n", c.CommandPath())
 		}
 		return c, err
 	}
@@ -1162,7 +1166,7 @@ func (c *Command) ValidateRequiredFlags() error {
 	})
 
 	if len(missingFlagNames) > 0 {
-		return fmt.Errorf(`required flag(s) "%s" not set`, strings.Join(missingFlagNames, `", "`))
+		return fmt.Errorf(i18nFlagNotSetError(len(missingFlagNames)), strings.Join(missingFlagNames, `", "`))
 	}
 	return nil
 }
@@ -1186,9 +1190,9 @@ func (c *Command) checkCommandGroups() {
 func (c *Command) InitDefaultHelpFlag() {
 	c.mergePersistentFlags()
 	if c.Flags().Lookup("help") == nil {
-		usage := "help for "
+		usage := i18nHelpFor() + " "
 		if c.Name() == "" {
-			usage += "this command"
+			usage += i18nThisCommand()
 		} else {
 			usage += c.Name()
 		}
@@ -1208,9 +1212,9 @@ func (c *Command) InitDefaultVersionFlag() {
 
 	c.mergePersistentFlags()
 	if c.Flags().Lookup("version") == nil {
-		usage := "version for "
+		usage := i18nVersionFor() + " "
 		if c.Name() == "" {
-			usage += "this command"
+			usage += i18nThisCommand()
 		} else {
 			usage += c.Name()
 		}
@@ -1233,10 +1237,9 @@ func (c *Command) InitDefaultHelpCmd() {
 
 	if c.helpCommand == nil {
 		c.helpCommand = &Command{
-			Use:   "help [command]",
+			Use:   fmt.Sprintf("help [%s]", i18nCommand()),
-			Short: "Help about any command",
+			Short: i18nCommandHelpShort(),
-			Long: `Help provides help for any command in the application.
+			Long:  fmt.Sprintf(i18nCommandHelpLong(), c.Name()+fmt.Sprintf(" help [%s]", i18nPathToCommand())),
-Simply type ` + c.Name() + ` help [path to command] for full details.`,
 			ValidArgsFunction: func(c *Command, args []string, toComplete string) ([]string, ShellCompDirective) {
 				var completions []string
 				cmd, _, e := c.Root().Find(args)
@@ -1259,7 +1262,7 @@ Simply type ` + c.Name() + ` help [path to command] for full details.`,
 			Run: func(c *Command, args []string) {
 				cmd, _, e := c.Root().Find(args)
 				if cmd == nil || e != nil {
-					c.Printf("Unknown help topic %#q\n", args)
+					c.Printf(i18nCommandHelpUnknownTopicError()+"\n", args)
 					CheckErr(c.Root().Usage())
 				} else {
 					cmd.InitDefaultHelpFlag()    // make possible 'help' flag to be shown

command_test.go

@@ -815,6 +815,21 @@ func TestPersistentFlagsOnChild(t *testing.T) {
 	}
 }
 
+func TestRequiredFlag(t *testing.T) {
+	c := &Command{Use: "c", Run: emptyRun}
+	c.Flags().String("foo1", "", "")
+	assertNoErr(t, c.MarkFlagRequired("foo1"))
+
+	expected := fmt.Sprintf("required flag %q is not set", "foo1")
+
+	_, err := executeCommand(c)
+	got := err.Error()
+
+	if got != expected {
+		t.Errorf("Expected error: %q, got: %q", expected, got)
+	}
+}
+
 func TestRequiredFlags(t *testing.T) {
 	c := &Command{Use: "c", Run: emptyRun}
 	c.Flags().String("foo1", "", "")
@@ -823,7 +838,7 @@ func TestRequiredFlags(t *testing.T) {
 	assertNoErr(t, c.MarkFlagRequired("foo2"))
 	c.Flags().String("bar", "", "")
 
-	expected := fmt.Sprintf("required flag(s) %q, %q not set", "foo1", "foo2")
+	expected := fmt.Sprintf("required flags %q, %q are not set", "foo1", "foo2")
 
 	_, err := executeCommand(c)
 	got := err.Error()
@@ -850,7 +865,7 @@ func TestPersistentRequiredFlags(t *testing.T) {
 
 	parent.AddCommand(child)
 
-	expected := fmt.Sprintf("required flag(s) %q, %q, %q, %q not set", "bar1", "bar2", "foo1", "foo2")
+	expected := fmt.Sprintf("required flags %q, %q, %q, %q are not set", "bar1", "bar2", "foo1", "foo2")
 
 	_, err := executeCommand(parent, "child")
 	if err.Error() != expected {

flag_groups.go

@@ -201,7 +201,7 @@ func validateExclusiveFlagGroups(data map[string]map[string]bool) error {
 
 		// Sort values, so they can be tested/scripted against consistently.
 		sort.Strings(set)
-		return fmt.Errorf("if any flags in the group [%v] are set none of the others can be; %v were all set", flagList, set)
+		return fmt.Errorf(i18nExclusiveFlagsValidationError(), flagList, set)
 	}
 	return nil
 }

go.mod

@@ -1,10 +1,13 @@
 module github.com/spf13/cobra
 
-go 1.15
+go 1.16
 
 require (
+	github.com/BurntSushi/toml v1.0.0
 	github.com/cpuguy83/go-md2man/v2 v2.0.3
 	github.com/inconshreveable/mousetrap v1.1.0
+	github.com/nicksnyder/go-i18n/v2 v2.2.1
 	github.com/spf13/pflag v1.0.5
+	golang.org/x/text v0.4.0
 	gopkg.in/yaml.v3 v3.0.1
 )

go.sum

@@ -1,12 +1,43 @@
+github.com/BurntSushi/toml v1.0.0 h1:dtDWrepsVPfW9H/4y7dDgFc2MBUSeJhlaDtK13CxFlU=
+github.com/BurntSushi/toml v1.0.0/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
 github.com/cpuguy83/go-md2man/v2 v2.0.3 h1:qMCsGGgs+MAzDFyp9LpAe1Lqy/fY/qCovCm0qnXZOBM=
 github.com/cpuguy83/go-md2man/v2 v2.0.3/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
+github.com/nicksnyder/go-i18n/v2 v2.2.1 h1:aOzRCdwsJuoExfZhoiXHy4bjruwCMdt5otbYojM/PaA=
+github.com/nicksnyder/go-i18n/v2 v2.2.1/go.mod h1:fF2++lPHlo+/kPaj3nB0uxtPwzlPm+BlgwGX7MkeGj0=
 github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
+golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
+golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
+golang.org/x/text v0.4.0 h1:BrVqGRd7+k1DiOgtnFvAkoQEWQvBc25ouMJM6429SFg=
+golang.org/x/text v0.4.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.3.0 h1:clyUAQHOM3G0M3f5vQj7LuJrETvjVot3Z5el9nffUtU=
+gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

localizer.go

@@ -0,0 +1,390 @@
+package cobra
+
+import (
+	"embed"
+	"fmt"
+	"os"
+
+	"github.com/BurntSushi/toml"
+	"github.com/nicksnyder/go-i18n/v2/i18n"
+	"golang.org/x/text/language"
+)
+
+var defaultLanguage = language.English
+
+// envVariablesHoldingLocale is sorted by decreasing priority
+// These environment variables are expected to hold a parsable locale (fr_FR, es, en-US, …)
+var envVariablesHoldingLocale = []string{
+	"LANGUAGE",
+	"LC_ALL",
+	"LANG",
+}
+
+// localeFS points to an embedded filesystem of TOML translation files
+//
+//go:embed translations/*.toml
+var localeFS embed.FS
+
+// Localizer can be used to fetch localized messages
+var localizer *i18n.Localizer
+
+type i18nCommandGlossary struct {
+	SectionUsage                string
+	SectionAliases              string
+	SectionExamples             string
+	SectionAvailableCommands    string
+	SectionAdditionalCommands   string
+	SectionFlags                string
+	SectionGlobalFlags          string
+	SectionAdditionalHelpTopics string
+	Use                         string
+	ForInfoAboutCommand         string
+}
+
+type CommandUsageTemplateData struct {
+	*Command
+	I18n *i18nCommandGlossary
+}
+
+var commonCommandGlossary *i18nCommandGlossary
+
+func getCommandGlossary() *i18nCommandGlossary {
+	if commonCommandGlossary == nil {
+		commonCommandGlossary = &i18nCommandGlossary{
+			SectionUsage:                i18nSectionUsage(),
+			SectionAliases:              i18nSectionAliases(),
+			SectionExamples:             i18nSectionExamples(),
+			SectionAvailableCommands:    i18nSectionAvailableCommands(),
+			SectionAdditionalCommands:   i18nSectionAdditionalCommands(),
+			SectionFlags:                i18nSectionFlags(),
+			SectionGlobalFlags:          i18nSectionGlobalFlags(),
+			SectionAdditionalHelpTopics: i18nSectionAdditionalHelpTopics(),
+			Use:                         i18nUse(),
+			ForInfoAboutCommand:         i18nForInfoAboutCommand(),
+		}
+	}
+	return commonCommandGlossary
+}
+
+func i18nSectionUsage() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "SectionUsage",
+		Description: "title of the section in the usage template",
+		Other:       "Usage",
+	})
+}
+
+func i18nSectionAliases() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "SectionAliases",
+		Description: "title of the section in the usage template",
+		Other:       "Aliases",
+	})
+}
+
+func i18nSectionExamples() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "SectionExamples",
+		Description: "title of the section in the usage template",
+		Other:       "Examples",
+	})
+}
+
+func i18nSectionAvailableCommands() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "SectionAvailableCommands",
+		Description: "title of the section in the usage template",
+		Other:       "Available Commands",
+	})
+}
+
+func i18nSectionAdditionalCommands() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "SectionAdditionalCommands",
+		Description: "title of the section in the usage template",
+		Other:       "Additional Commands",
+	})
+}
+
+func i18nSectionFlags() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "SectionFlags",
+		Description: "title of the section in the usage template",
+		Other:       "Flags",
+	})
+}
+
+func i18nSectionGlobalFlags() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "SectionGlobalFlags",
+		Description: "title of the section in the usage template",
+		Other:       "Global Flags",
+	})
+}
+
+func i18nSectionAdditionalHelpTopics() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "SectionAdditionalHelpTopics",
+		Description: "title of the section in the usage template",
+		Other:       "Additional Help Topics",
+	})
+}
+
+func i18nUse() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "Use",
+		Description: "beginning of a sentence like 'Use <this> to do <that>'",
+		Other:       "Use",
+	})
+}
+
+func i18nForInfoAboutCommand() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "ForInfoAboutCommand",
+		Description: "end of a sentence",
+		Other:       "for more information about a command",
+	})
+}
+
+func i18nCommand() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "Command",
+		Description: "lowercase",
+		Other:       "command",
+	})
+}
+
+func i18nPathToCommand() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "PathToCommand",
+		Description: "lowercase",
+		Other:       "path to command",
+	})
+}
+
+func i18nCommandHelpShort() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "CommandHelpShort",
+		Description: "short help for command help",
+		Other:       "Help about any command",
+	})
+}
+
+func i18nCommandHelpLong() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "CommandHelpLong",
+		Description: "long help for command help (cmd example)",
+		Other: `Help provides help for any command in the application.
+Simply type %s for full details.`,
+	})
+}
+
+func i18nCommandHelpUnknownTopicError() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "CommandHelpUnknownTopicError",
+		Description: "shown when help topic is unknown (args)",
+		Other:       "Unknown help topic %#q",
+	})
+}
+
+func i18nHelpFor() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "HelpFor",
+		Description: "lowercase, beginning of sentence",
+		Other:       "help for",
+	})
+}
+
+func i18nVersionFor() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "VersionFor",
+		Description: "lowercase, beginning of sentence",
+		Other:       "version for",
+	})
+}
+
+func i18nThisCommand() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "ThisCommand",
+		Description: "lowercase, end of sentence, used when command name is undefined",
+		Other:       "this command",
+	})
+}
+
+func i18nDidYouMeanThis() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "DidYouMeanThis",
+		Description: "shown as suggestion",
+		Other:       "Did you mean this?",
+	})
+}
+
+func i18nCommandDeprecatedWarning() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "CommandDeprecatedWarning",
+		Description: "printed when a deprecated command is executed (cmd, deprecation message)",
+		Other:       "Command %q is deprecated, %s",
+	})
+}
+
+func i18nError() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "Error",
+		Description: "prefix of error messages",
+		Other:       "Error",
+	})
+}
+
+func i18nLegacyArgsValidationError() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "LegacyArgsValidationError",
+		Description: "error shown when args are not understood (subcmd, cmd, suggestion)",
+		Other:       "unknown command %q for %q%s",
+	})
+}
+
+func i18nNoArgsValidationError() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "NoArgsValidationError",
+		Description: "error shown when args are present but should not (subcmd, cmd)",
+		Other:       "unknown command %q for %q",
+	})
+}
+
+func i18nOnlyValidArgsValidationError() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "OnlyValidArgsValidationError",
+		Description: "error shown when arg is invalid (arg, cmd, suggestion)",
+		Other:       "invalid argument %q for %q%s",
+	})
+}
+
+func i18nMinimumNArgsValidationError(amountRequired int) string {
+	return localizeMessageWithPlural(&i18n.Message{
+		ID:          "MinimumNArgsValidationError",
+		Description: "error shown when arg count is too low (expected amount, actual amount)",
+		Other:       "requires at least %d args, only received %d",
+		One:         "requires at least %d arg, only received %d",
+	}, amountRequired)
+}
+
+func i18nMaximumNArgsValidationError(amountRequired int) string {
+	return localizeMessageWithPlural(&i18n.Message{
+		ID:          "MaximumNArgsValidationError",
+		Description: "error shown when arg count is too low (expected amount, actual amount)",
+		Other:       "accepts at most %d args, received %d",
+		One:         "accepts at most %d arg, received %d",
+	}, amountRequired)
+}
+
+func i18nExactArgsValidationError(amountRequired int) string {
+	return localizeMessageWithPlural(&i18n.Message{
+		ID:          "ExactArgsValidationError",
+		Description: "error shown when arg count is not exact (expected amount, actual amount)",
+		Other:       "accepts %d args, received %d",
+		One:         "accepts %d arg, received %d",
+	}, amountRequired)
+}
+
+func i18nRangeArgsValidationError(amountMax int) string {
+	return localizeMessageWithPlural(&i18n.Message{
+		ID:          "RangeArgsValidationError",
+		Description: "error shown when arg count is not in range (expected min, expected max, actual amount)",
+		Other:       "accepts between %d and %d args, received %d",
+		One:         "accepts between %d and %d arg, received %d",
+	}, amountMax)
+}
+
+func i18nRunHelpTip() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "RunHelpTip",
+		Description: "tip shown when a command fails (command path)",
+		Other:       "Run '%v --help' for usage.",
+	})
+}
+
+func i18nExclusiveFlagsValidationError() string {
+	return localizeMessage(&i18n.Message{
+		ID:          "ExclusiveFlagsValidationError",
+		Description: "error shown when multiple exclusive flags are provided (group flags, offending flags)",
+		Other:       "if any flags in the group [%v] are set none of the others can be; %v were all set",
+	})
+}
+
+func i18nFlagNotSetError(amountFlags int) string {
+	return localizeMessageWithPlural(&i18n.Message{
+		ID:          "FlagNotSetError",
+		Description: "error shown when required flags are not set (flags)",
+		Other:       "required flags \"%s\" are not set",
+		One:         "required flag \"%s\" is not set",
+	}, amountFlags)
+}
+
+// … lots more translations here
+
+func localizeMessage(message *i18n.Message) string {
+	localizedValue, err := localizer.Localize(&i18n.LocalizeConfig{
+		DefaultMessage: message,
+	})
+	if err != nil {
+		return message.Other
+	}
+
+	return localizedValue
+}
+
+func localizeMessageWithPlural(message *i18n.Message, pluralCount int) string {
+	localizedValue, err := localizer.Localize(&i18n.LocalizeConfig{
+		PluralCount:    pluralCount,
+		DefaultMessage: message,
+	})
+	if err != nil {
+		return message.Other
+	}
+
+	return localizedValue
+}
+
+func loadTranslationFiles(bundle *i18n.Bundle, langs []string) {
+	for _, lang := range langs {
+		_, _ = bundle.LoadMessageFileFS(localeFS, fmt.Sprintf("translations/active.%s.toml", lang))
+	}
+}
+
+func detectLangs() []string {
+	var detectedLangs []string
+	for _, envKey := range envVariablesHoldingLocale {
+		lang := os.Getenv(envKey)
+		if lang != "" {
+			detectedLang := language.Make(lang)
+			appendLang(&detectedLangs, detectedLang)
+		}
+	}
+	appendLang(&detectedLangs, defaultLanguage)
+
+	return detectedLangs
+}
+
+func appendLang(langs *[]string, lang language.Tag) {
+	langString := lang.String()
+	*langs = append(*langs, langString)
+
+	langBase, confidentInBase := lang.Base()
+	if confidentInBase != language.No {
+		*langs = append(*langs, langBase.String())
+		*langs = append(*langs, langBase.ISO3())
+	}
+}
+
+func setupLocalizer() {
+	bundle := i18n.NewBundle(defaultLanguage)
+	bundle.RegisterUnmarshalFunc("toml", toml.Unmarshal)
+	detectedLangs := detectLangs()
+	//fmt.Println("Detected languages", detectedLangs)
+	loadTranslationFiles(bundle, detectedLangs)
+	localizer = i18n.NewLocalizer(bundle, detectedLangs...)
+}
+
+func init() {
+	setupLocalizer() // FIXME: perhaps hook this somewhere else?  (not init)
+}

translations/active.en.toml

@@ -0,0 +1,128 @@
+[Command]
+description = "lowercase"
+other = "command"
+
+[CommandDeprecatedWarning]
+description = "printed when a deprecated command is executed (cmd, deprecation message)"
+other = "Command %q is deprecated, %s"
+
+[CommandHelpLong]
+description = "long help for command help (cmd example)"
+other = "Help provides help for any command in the application.\nSimply type %s for full details."
+
+[CommandHelpShort]
+description = "short help for command help"
+other = "Help about any command"
+
+[CommandHelpUnknownTopicError]
+description = "shown when help topic is unknown (args)"
+other = "Unknown help topic %#q"
+
+[DidYouMeanThis]
+description = "shown as suggestion"
+other = "Did you mean this?"
+
+[Error]
+description = "prefix of error messages"
+other = "Error"
+
+[ExactArgsValidationError]
+description = "error shown when arg count is not exact (expected amount, actual amount)"
+one = "accepts %d arg, received %d"
+other = "accepts %d args, received %d"
+
+[ExclusiveFlagsValidationError]
+description = "error shown when multiple exclusive flags are provided (group flags, offending flags)"
+other = "if any flags in the group [%v] are set none of the others can be; %v were all set"
+
+[FlagNotSetError]
+description = "error shown when required flags are not set (flags)"
+one = "required flag \"%s\" is not set"
+other = "required flags \"%s\" are not set"
+
+[ForInfoAboutCommand]
+description = "end of a sentence"
+other = "for more information about a command"
+
+[HelpFor]
+description = "lowercase, beginning of sentence"
+other = "help for"
+
+[LegacyArgsValidationError]
+description = "error shown when args are not understood (subcmd, cmd, suggestion)"
+other = "unknown command %q for %q%s"
+
+[MaximumNArgsValidationError]
+description = "error shown when arg count is too low (expected amount, actual amount)"
+one = "accepts at most %d arg, received %d"
+other = "accepts at most %d args, received %d"
+
+[MinimumNArgsValidationError]
+description = "error shown when arg count is too low (expected amount, actual amount)"
+one = "requires at least %d arg, only received %d"
+other = "requires at least %d args, only received %d"
+
+[NoArgsValidationError]
+description = "error shown when args are present but should not (subcmd, cmd)"
+other = "unknown command %q for %q"
+
+[OnlyValidArgsValidationError]
+description = "error shown when arg is invalid (arg, cmd, suggestion)"
+other = "invalid argument %q for %q%s"
+
+[PathToCommand]
+description = "lowercase"
+other = "path to command"
+
+[RangeArgsValidationError]
+description = "error shown when arg count is not in range (expected min, expected max, actual amount)"
+one = "accepts between %d and %d arg, received %d"
+other = "accepts between %d and %d args, received %d"
+
+[RunHelpTip]
+description = "tip shown when a command fails (command path)"
+other = "Run '%v --help' for usage."
+
+[SectionAdditionalCommands]
+description = "title of the section in the usage template"
+other = "Additional Commands"
+
+[SectionAdditionalHelpTopics]
+description = "title of the section in the usage template"
+other = "Additional Help Topics"
+
+[SectionAliases]
+description = "title of the section in the usage template"
+other = "Aliases"
+
+[SectionAvailableCommands]
+description = "title of the section in the usage template"
+other = "Available Commands"
+
+[SectionExamples]
+description = "title of the section in the usage template"
+other = "Examples"
+
+[SectionFlags]
+description = "title of the section in the usage template"
+other = "Flags"
+
+[SectionGlobalFlags]
+description = "title of the section in the usage template"
+other = "Global Flags"
+
+[SectionUsage]
+description = "title of the section in the usage template"
+other = "Usage"
+
+[ThisCommand]
+description = "lowercase, end of sentence, used when command name is undefined"
+other = "this command"
+
+[Use]
+description = "beginning of a sentence like 'Use <this> to do <that>'"
+other = "Use"
+
+[VersionFor]
+description = "lowercase, beginning of sentence"
+other = "version for"

translations/active.fr.toml

@@ -0,0 +1,159 @@
+[Command]
+description = "lowercase"
+hash = "sha1-c90bde9bb93ee6452afbe579d55cd32ba0159c8d"
+other = "commande"
+
+[CommandDeprecatedWarning]
+description = "printed when a deprecated command is executed (cmd, deprecation message)"
+hash = "sha1-e8b974a255eafe86d4a4fe15a0e79aaab345354c"
+other = "La commande %q est dépréciée, %s"
+
+[CommandHelpLong]
+description = "long help for command help (cmd example)"
+hash = "sha1-dc993d9f12d54910147c477318fa82c8210b6669"
+other = "Help fournit de l'aide pour n'importe quelle commande de l'application.\nTapez '%s' pour obtenir une aide détaillée."
+
+[CommandHelpShort]
+description = "short help for command help"
+hash = "sha1-5bab4a463f36ea8e33681f523445bbd614e9891c"
+other = "Obtenir de l'aide au sujet d'une commande"
+
+[CommandHelpUnknownTopicError]
+description = "shown when help topic is unknown (args)"
+hash = "sha1-d3b6cb615eee5770e0e8e62fbf7a3293502dd7a8"
+other = "Sujet d'aide %#q inconnu"
+
+[DidYouMeanThis]
+description = "shown as suggestion"
+hash = "sha1-eb9504fe384499caafe690853204c7fb7ac8b531"
+other = "Vouliez-vous dire ceci ?"
+
+[Error]
+description = "prefix of error messages"
+hash = "sha1-7dcb56355a3ddc7ff7e5ccd6522507999ca7f238"
+other = "Erreur"
+
+[ExactArgsValidationError]
+description = "error shown when arg count is not exact (expected amount, actual amount)"
+hash = "sha1-207d771f1d5dc4ed5c4094dcd29a4c80e31a6260"
+one = "accepte %d arg, mais en a reçu %d"
+other = "accepte %d args, mais en en reçu %d"
+
+[ExclusiveFlagsValidationError]
+description = "error shown when multiple exclusive flags are provided (group flags, offending flags)"
+hash = "sha1-221b98bada52cfc2932f9aa5142b653b46baded6"
+other = "les options [%v] sont exclusives, mais les options %v ont été fournies"
+
+[FlagNotSetError]
+description = "error shown when required flags are not set (flags)"
+hash = "sha1-f5340c4bfceb0066ec70944b57e6458b6f8cc97b"
+one = "l'option requise \"%s\" n'est pas présente"
+other = "les options requises \"%s\" ne sont pas présentes"
+
+[ForInfoAboutCommand]
+description = "end of a sentence"
+hash = "sha1-923f6d48908b3a6981fb5504b0e5078700a312c0"
+other = "pour plus d'information au sujet d'une commande"
+
+[HelpFor]
+description = "lowercase, beginning of sentence"
+hash = "sha1-18fbe8d2780935dbe6a71f998821c22f283cbd25"
+other = "aide pour"
+
+[LegacyArgsValidationError]
+description = "error shown when args are not understood (subcmd, cmd, suggestion)"
+hash = "sha1-c601c68bdcb9687109e793112b789b1858953b15"
+other = "commande %q inconnue pour %q%s"
+
+[MaximumNArgsValidationError]
+description = "error shown when arg count is too low (expected amount, actual amount)"
+hash = "sha1-86d71b8bc054ea8aad7006808bc9d96551052ab4"
+one = "accepte au plus %d arg, mais en a reçu %d"
+other = "accepte au plus %d args, mais en a reçu %d"
+
+[MinimumNArgsValidationError]
+description = "error shown when arg count is too low (expected amount, actual amount)"
+hash = "sha1-7cc9093bf167d6f0601dd0763a8d3f10d71c8889"
+one = "requiert au moins %d arg, mais en a reçu %d"
+other = "requiert au moins %d args, mais en a reçu %d"
+
+[NoArgsValidationError]
+description = "error shown when args are present but should not (subcmd, cmd)"
+hash = "sha1-551d8d237dc2ab9a853fcfbe7ef85318a0f78720"
+other = "commande %q inconnue pour %q"
+
+[OnlyValidArgsValidationError]
+description = "error shown when arg is invalid (arg, cmd, suggestion)"
+hash = "sha1-60b40e5782dd252c78ef3d585065cb99197ec22e"
+other = "argument %q invalide pour %q%s"
+
+[PathToCommand]
+description = "lowercase"
+hash = "sha1-7dcca04d5dcb7ff289a5483bea3e4f1e4119c1f4"
+other = "commande"
+
+[RangeArgsValidationError]
+description = "error shown when arg count is not in range (expected min, expected max, actual amount)"
+hash = "sha1-aa81e0aee17a3439b479cdf47169eb194706cd14"
+one = "accepte entre %d et %d arg, mais en a reçu %d"
+other = "accepte entre %d et %d args, mais en a reçu %d"
+
+[RunHelpTip]
+description = "tip shown when a command fails (command path)"
+hash = "sha1-e1d2c4cccd484df365c3249347d5172981929b88"
+other = "Essayez '%v --help' pour obtenir de l'aide."
+
+[SectionAdditionalCommands]
+description = "title of the section in the usage template"
+hash = "sha1-730484f22c7ce0885ca13a3b8222b231dc29a4a9"
+other = "Commandes Connexes"
+
+[SectionAdditionalHelpTopics]
+description = "title of the section in the usage template"
+hash = "sha1-615c9551f4dcd30836fbe04506e0b807c59dd901"
+other = "Autres Sujets"
+
+[SectionAliases]
+description = "title of the section in the usage template"
+hash = "sha1-3c66c036f454cb3d23f757c430a5c05b148dc01f"
+other = "Alias"
+
+[SectionAvailableCommands]
+description = "title of the section in the usage template"
+hash = "sha1-fc33c38777373e51c9c84c8594efb5de4df0f23e"
+other = "Commandes Disponibles"
+
+[SectionExamples]
+description = "title of the section in the usage template"
+hash = "sha1-6e2f0c7dddc3ce6aacb1184b3b21694492d6595a"
+other = "Exemples"
+
+[SectionFlags]
+description = "title of the section in the usage template"
+hash = "sha1-5513ed25ed4e1ad2e569ff4c963bba347320e9f7"
+other = "Options"
+
+[SectionGlobalFlags]
+description = "title of the section in the usage template"
+hash = "sha1-705f1ebcdce1374e23f41bc8e0e14e5197ac1742"
+other = "Options Globales"
+
+[SectionUsage]
+description = "title of the section in the usage template"
+hash = "sha1-5fdae7bd171315a453063384887ee4300363cf20"
+other = "Usage"
+
+[ThisCommand]
+description = "lowercase, end of sentence, used when command name is undefined"
+hash = "sha1-5cfa4629fdf18b89471b3d07a0d051a8a10afe70"
+other = "cette commande"
+
+[Use]
+description = "beginning of a sentence like 'Use <this> to do <that>'"
+hash = "sha1-f42c92acc9934eec952161dfa338a95ec0f02b75"
+other = "Utilisez"
+
+[VersionFor]
+description = "lowercase, beginning of sentence"
+hash = "sha1-e7f03028ab18076d111cd3343a24bbd8113d5431"
+other = "version de"