vendor/github.com/urfave/cli/v2/flag.go - cos/tools - Git at Google

 package cli

 import (
 	"errors"
 	"flag"
 	"fmt"
 	"io"
 	"os"
 	"regexp"
 	"runtime"
 	"strings"
 	"syscall"
 	"time"
 )

 const defaultPlaceholder = "value"

 const (
 	defaultSliceFlagSeparator = ","
 	disableSliceFlagSeparator = false
 )

 var (
 	slPfx = fmt.Sprintf("sl:::%d:::", time.Now().UTC().UnixNano())

 	commaWhitespace = regexp.MustCompile("[, ]+.*")
 )

 // BashCompletionFlag enables bash-completion for all commands and subcommands
 var BashCompletionFlag Flag = &BoolFlag{
 	Name:   "generate-bash-completion",
 	Hidden: true,
 }

 // VersionFlag prints the version for the application
 var VersionFlag Flag = &BoolFlag{
 	Name:               "version",
 	Aliases:            []string{"v"},
 	Usage:              "print the version",
 	DisableDefaultText: true,
 }

 // HelpFlag prints the help for all commands and subcommands.
 // Set to nil to disable the flag.  The subcommand
 // will still be added unless HideHelp or HideHelpCommand is set to true.
 var HelpFlag Flag = &BoolFlag{
 	Name:               "help",
 	Aliases:            []string{"h"},
 	Usage:              "show help",
 	DisableDefaultText: true,
 }

 // FlagStringer converts a flag definition to a string. This is used by help
 // to display a flag.
 var FlagStringer FlagStringFunc = stringifyFlag

 // Serializer is used to circumvent the limitations of flag.FlagSet.Set
 type Serializer interface {
 	Serialize() string
 }

 // FlagNamePrefixer converts a full flag name and its placeholder into the help
 // message flag prefix. This is used by the default FlagStringer.
 var FlagNamePrefixer FlagNamePrefixFunc = prefixedNames

 // FlagEnvHinter annotates flag help message with the environment variable
 // details. This is used by the default FlagStringer.
 var FlagEnvHinter FlagEnvHintFunc = withEnvHint

 // FlagFileHinter annotates flag help message with the environment variable
 // details. This is used by the default FlagStringer.
 var FlagFileHinter FlagFileHintFunc = withFileHint

 // FlagsByName is a slice of Flag.
 type FlagsByName []Flag

 func (f FlagsByName) Len() int {
 	return len(f)
 }

 func (f FlagsByName) Less(i, j int) bool {
 	if len(f[j].Names()) == 0 {
 		return false
 	} else if len(f[i].Names()) == 0 {
 		return true
 	}
 	return lexicographicLess(f[i].Names()[0], f[j].Names()[0])
 }

 func (f FlagsByName) Swap(i, j int) {
 	f[i], f[j] = f[j], f[i]
 }

 // ActionableFlag is an interface that wraps Flag interface and RunAction operation.
 type ActionableFlag interface {
 	Flag
 	RunAction(*Context) error
 }

 // Flag is a common interface related to parsing flags in cli.
 // For more advanced flag parsing techniques, it is recommended that
 // this interface be implemented.
 type Flag interface {
 	fmt.Stringer
 	// Apply Flag settings to the given flag set
 	Apply(*flag.FlagSet) error
 	Names() []string
 	IsSet() bool
 }

 // RequiredFlag is an interface that allows us to mark flags as required
 // it allows flags required flags to be backwards compatible with the Flag interface
 type RequiredFlag interface {
 	Flag

 	IsRequired() bool
 }

 // DocGenerationFlag is an interface that allows documentation generation for the flag
 type DocGenerationFlag interface {
 	Flag

 	// TakesValue returns true if the flag takes a value, otherwise false
 	TakesValue() bool

 	// GetUsage returns the usage string for the flag
 	GetUsage() string

 	// GetValue returns the flags value as string representation and an empty
 	// string if the flag takes no value at all.
 	GetValue() string

 	// GetDefaultText returns the default text for this flag
 	GetDefaultText() string

 	// GetEnvVars returns the env vars for this flag
 	GetEnvVars() []string
 }

 // DocGenerationSliceFlag extends DocGenerationFlag for slice-based flags.
 type DocGenerationSliceFlag interface {
 	DocGenerationFlag

 	// IsSliceFlag returns true for flags that can be given multiple times.
 	IsSliceFlag() bool
 }

 // VisibleFlag is an interface that allows to check if a flag is visible
 type VisibleFlag interface {
 	Flag

 	// IsVisible returns true if the flag is not hidden, otherwise false
 	IsVisible() bool
 }

 // CategorizableFlag is an interface that allows us to potentially
 // use a flag in a categorized representation.
 type CategorizableFlag interface {
 	VisibleFlag

 	GetCategory() string
 }

 // Countable is an interface to enable detection of flag values which support
 // repetitive flags
 type Countable interface {
 	Count() int
 }

 func flagSet(name string, flags []Flag, spec separatorSpec) (*flag.FlagSet, error) {
 	set := flag.NewFlagSet(name, flag.ContinueOnError)

 	for _, f := range flags {
 		if c, ok := f.(customizedSeparator); ok {
 			c.WithSeparatorSpec(spec)
 		}
 		if err := f.Apply(set); err != nil {
 			return nil, err
 		}
 	}
 	set.SetOutput(io.Discard)
 	return set, nil
 }

 func copyFlag(name string, ff *flag.Flag, set *flag.FlagSet) {
 	switch ff.Value.(type) {
 	case Serializer:
 		_ = set.Set(name, ff.Value.(Serializer).Serialize())
 	default:
 		_ = set.Set(name, ff.Value.String())
 	}
 }

 func normalizeFlags(flags []Flag, set *flag.FlagSet) error {
 	visited := make(map[string]bool)
 	set.Visit(func(f *flag.Flag) {
 		visited[f.Name] = true
 	})
 	for _, f := range flags {
 		parts := f.Names()
 		if len(parts) == 1 {
 			continue
 		}
 		var ff *flag.Flag
 		for _, name := range parts {
 			name = strings.Trim(name, " ")
 			if visited[name] {
 				if ff != nil {
 					return errors.New("Cannot use two forms of the same flag: " + name + " " + ff.Name)
 				}
 				ff = set.Lookup(name)
 			}
 		}
 		if ff == nil {
 			continue
 		}
 		for _, name := range parts {
 			name = strings.Trim(name, " ")
 			if !visited[name] {
 				copyFlag(name, ff, set)
 			}
 		}
 	}
 	return nil
 }

 func visibleFlags(fl []Flag) []Flag {
 	var visible []Flag
 	for _, f := range fl {
 		if vf, ok := f.(VisibleFlag); ok && vf.IsVisible() {
 			visible = append(visible, f)
 		}
 	}
 	return visible
 }

 func prefixFor(name string) (prefix string) {
 	if len(name) == 1 {
 		prefix = "-"
 	} else {
 		prefix = "--"
 	}

 	return
 }

 // Returns the placeholder, if any, and the unquoted usage string.
 func unquoteUsage(usage string) (string, string) {
 	for i := 0; i < len(usage); i++ {
 		if usage[i] == '`' {
 			for j := i + 1; j < len(usage); j++ {
 				if usage[j] == '`' {
 					name := usage[i+1 : j]
 					usage = usage[:i] + name + usage[j+1:]
 					return name, usage
 				}
 			}
 			break
 		}
 	}
 	return "", usage
 }

 func prefixedNames(names []string, placeholder string) string {
 	var prefixed string
 	for i, name := range names {
 		if name == "" {
 			continue
 		}

 		prefixed += prefixFor(name) + name
 		if placeholder != "" {
 			prefixed += " " + placeholder
 		}
 		if i < len(names)-1 {
 			prefixed += ", "
 		}
 	}
 	return prefixed
 }

 func envFormat(envVars []string, prefix, sep, suffix string) string {
 	if len(envVars) > 0 {
 		return fmt.Sprintf(" [%s%s%s]", prefix, strings.Join(envVars, sep), suffix)
 	}
 	return ""
 }

 func defaultEnvFormat(envVars []string) string {
 	return envFormat(envVars, "$", ", $", "")
 }

 func withEnvHint(envVars []string, str string) string {
 	envText := ""
 	if runtime.GOOS != "windows" || os.Getenv("PSHOME") != "" {
 		envText = defaultEnvFormat(envVars)
 	} else {
 		envText = envFormat(envVars, "%", "%, %", "%")
 	}
 	return str + envText
 }

 func FlagNames(name string, aliases []string) []string {
 	var ret []string

 	for _, part := range append([]string{name}, aliases...) {
 		// v1 -> v2 migration warning zone:
 		// Strip off anything after the first found comma or space, which
 		// *hopefully* makes it a tiny bit more obvious that unexpected behavior is
 		// caused by using the v1 form of stringly typed "Name".
 		ret = append(ret, commaWhitespace.ReplaceAllString(part, ""))
 	}

 	return ret
 }

 func withFileHint(filePath, str string) string {
 	fileText := ""
 	if filePath != "" {
 		fileText = fmt.Sprintf(" [%s]", filePath)
 	}
 	return str + fileText
 }

 func formatDefault(format string) string {
 	return " (default: " + format + ")"
 }

 func stringifyFlag(f Flag) string {
 	// enforce DocGeneration interface on flags to avoid reflection
 	df, ok := f.(DocGenerationFlag)
 	if !ok {
 		return ""
 	}

 	placeholder, usage := unquoteUsage(df.GetUsage())
 	needsPlaceholder := df.TakesValue()

 	if needsPlaceholder && placeholder == "" {
 		placeholder = defaultPlaceholder
 	}

 	defaultValueString := ""

 	// set default text for all flags except bool flags
 	// for bool flags display default text if DisableDefaultText is not
 	// set
 	if bf, ok := f.(*BoolFlag); !ok || !bf.DisableDefaultText {
 		if s := df.GetDefaultText(); s != "" {
 			defaultValueString = fmt.Sprintf(formatDefault("%s"), s)
 		}
 	}

 	usageWithDefault := strings.TrimSpace(usage + defaultValueString)

 	pn := prefixedNames(df.Names(), placeholder)
 	sliceFlag, ok := f.(DocGenerationSliceFlag)
 	if ok && sliceFlag.IsSliceFlag() {
 		pn = pn + " [ " + pn + " ]"
 	}

 	return withEnvHint(df.GetEnvVars(), fmt.Sprintf("%s\t%s", pn, usageWithDefault))
 }

 func hasFlag(flags []Flag, fl Flag) bool {
 	for _, existing := range flags {
 		if fl == existing {
 			return true
 		}
 	}

 	return false
 }

 // Return the first value from a list of environment variables and files
 // (which may or may not exist), a description of where the value was found,
 // and a boolean which is true if a value was found.
 func flagFromEnvOrFile(envVars []string, filePath string) (value string, fromWhere string, found bool) {
 	for _, envVar := range envVars {
 		envVar = strings.TrimSpace(envVar)
 		if value, found := syscall.Getenv(envVar); found {
 			return value, fmt.Sprintf("environment variable %q", envVar), true
 		}
 	}
 	for _, fileVar := range strings.Split(filePath, ",") {
 		if fileVar != "" {
 			if data, err := os.ReadFile(fileVar); err == nil {
 				return string(data), fmt.Sprintf("file %q", filePath), true
 			}
 		}
 	}
 	return "", "", false
 }

 type customizedSeparator interface {
 	WithSeparatorSpec(separatorSpec)
 }

 type separatorSpec struct {
 	sep        string
 	disabled   bool
 	customized bool
 }

 func (s separatorSpec) flagSplitMultiValues(val string) []string {
 	var (
 		disabled bool   = s.disabled
 		sep      string = s.sep
 	)
 	if !s.customized {
 		disabled = disableSliceFlagSeparator
 		sep = defaultSliceFlagSeparator
 	}
 	if disabled {
 		return []string{val}
 	}

 	return strings.Split(val, sep)
 }
	package cli

	import (
	"errors"
	"flag"
	"fmt"
	"io"
	"os"
	"regexp"
	"runtime"
	"strings"
	"syscall"
	"time"
	)

	const defaultPlaceholder = "value"

	const (
	defaultSliceFlagSeparator = ","
	disableSliceFlagSeparator = false
	)

	var (
	slPfx = fmt.Sprintf("sl:::%d:::", time.Now().UTC().UnixNano())

	commaWhitespace = regexp.MustCompile("[, ]+.*")
	)

	// BashCompletionFlag enables bash-completion for all commands and subcommands
	var BashCompletionFlag Flag = &BoolFlag{
	Name: "generate-bash-completion",
	Hidden: true,
	}

	// VersionFlag prints the version for the application
	var VersionFlag Flag = &BoolFlag{
	Name: "version",
	Aliases: []string{"v"},
	Usage: "print the version",
	DisableDefaultText: true,
	}

	// HelpFlag prints the help for all commands and subcommands.
	// Set to nil to disable the flag. The subcommand
	// will still be added unless HideHelp or HideHelpCommand is set to true.
	var HelpFlag Flag = &BoolFlag{
	Name: "help",
	Aliases: []string{"h"},
	Usage: "show help",
	DisableDefaultText: true,
	}

	// FlagStringer converts a flag definition to a string. This is used by help
	// to display a flag.
	var FlagStringer FlagStringFunc = stringifyFlag

	// Serializer is used to circumvent the limitations of flag.FlagSet.Set
	type Serializer interface {
	Serialize() string
	}

	// FlagNamePrefixer converts a full flag name and its placeholder into the help
	// message flag prefix. This is used by the default FlagStringer.
	var FlagNamePrefixer FlagNamePrefixFunc = prefixedNames

	// FlagEnvHinter annotates flag help message with the environment variable
	// details. This is used by the default FlagStringer.
	var FlagEnvHinter FlagEnvHintFunc = withEnvHint

	// FlagFileHinter annotates flag help message with the environment variable
	// details. This is used by the default FlagStringer.
	var FlagFileHinter FlagFileHintFunc = withFileHint

	// FlagsByName is a slice of Flag.
	type FlagsByName []Flag

	func (f FlagsByName) Len() int {
	return len(f)
	}

	func (f FlagsByName) Less(i, j int) bool {
	if len(f[j].Names()) == 0 {
	return false
	} else if len(f[i].Names()) == 0 {
	return true
	}
	return lexicographicLess(f[i].Names()[0], f[j].Names()[0])
	}

	func (f FlagsByName) Swap(i, j int) {
	f[i], f[j] = f[j], f[i]
	}

	// ActionableFlag is an interface that wraps Flag interface and RunAction operation.
	type ActionableFlag interface {
	Flag
	RunAction(*Context) error
	}

	// Flag is a common interface related to parsing flags in cli.
	// For more advanced flag parsing techniques, it is recommended that
	// this interface be implemented.
	type Flag interface {
	fmt.Stringer
	// Apply Flag settings to the given flag set
	Apply(*flag.FlagSet) error
	Names() []string
	IsSet() bool
	}

	// RequiredFlag is an interface that allows us to mark flags as required
	// it allows flags required flags to be backwards compatible with the Flag interface
	type RequiredFlag interface {
	Flag

	IsRequired() bool
	}

	// DocGenerationFlag is an interface that allows documentation generation for the flag
	type DocGenerationFlag interface {
	Flag

	// TakesValue returns true if the flag takes a value, otherwise false
	TakesValue() bool

	// GetUsage returns the usage string for the flag
	GetUsage() string

	// GetValue returns the flags value as string representation and an empty
	// string if the flag takes no value at all.
	GetValue() string

	// GetDefaultText returns the default text for this flag
	GetDefaultText() string

	// GetEnvVars returns the env vars for this flag
	GetEnvVars() []string
	}

	// DocGenerationSliceFlag extends DocGenerationFlag for slice-based flags.
	type DocGenerationSliceFlag interface {
	DocGenerationFlag

	// IsSliceFlag returns true for flags that can be given multiple times.
	IsSliceFlag() bool
	}

	// VisibleFlag is an interface that allows to check if a flag is visible
	type VisibleFlag interface {
	Flag

	// IsVisible returns true if the flag is not hidden, otherwise false
	IsVisible() bool
	}

	// CategorizableFlag is an interface that allows us to potentially
	// use a flag in a categorized representation.
	type CategorizableFlag interface {
	VisibleFlag

	GetCategory() string
	}

	// Countable is an interface to enable detection of flag values which support
	// repetitive flags
	type Countable interface {
	Count() int
	}

	func flagSet(name string, flags []Flag, spec separatorSpec) (*flag.FlagSet, error) {
	set := flag.NewFlagSet(name, flag.ContinueOnError)

	for _, f := range flags {
	if c, ok := f.(customizedSeparator); ok {
	c.WithSeparatorSpec(spec)
	}
	if err := f.Apply(set); err != nil {
	return nil, err
	}
	}
	set.SetOutput(io.Discard)
	return set, nil
	}

	func copyFlag(name string, ff flag.Flag, set flag.FlagSet) {
	switch ff.Value.(type) {
	case Serializer:
	_ = set.Set(name, ff.Value.(Serializer).Serialize())
	default:
	_ = set.Set(name, ff.Value.String())
	}
	}

	func normalizeFlags(flags []Flag, set *flag.FlagSet) error {
	visited := make(map[string]bool)
	set.Visit(func(f *flag.Flag) {
	visited[f.Name] = true
	})
	for _, f := range flags {
	parts := f.Names()
	if len(parts) == 1 {
	continue
	}
	var ff *flag.Flag
	for _, name := range parts {
	name = strings.Trim(name, " ")
	if visited[name] {
	if ff != nil {
	return errors.New("Cannot use two forms of the same flag: " + name + " " + ff.Name)
	}
	ff = set.Lookup(name)
	}
	}
	if ff == nil {
	continue
	}
	for _, name := range parts {
	name = strings.Trim(name, " ")
	if !visited[name] {
	copyFlag(name, ff, set)
	}
	}
	}
	return nil
	}

	func visibleFlags(fl []Flag) []Flag {
	var visible []Flag
	for _, f := range fl {
	if vf, ok := f.(VisibleFlag); ok && vf.IsVisible() {
	visible = append(visible, f)
	}
	}
	return visible
	}

	func prefixFor(name string) (prefix string) {
	if len(name) == 1 {
	prefix = "-"
	} else {
	prefix = "--"
	}

	return
	}

	// Returns the placeholder, if any, and the unquoted usage string.
	func unquoteUsage(usage string) (string, string) {
	for i := 0; i < len(usage); i++ {
	if usage[i] == '`' {
	for j := i + 1; j < len(usage); j++ {
	if usage[j] == '`' {
	name := usage[i+1 : j]
	usage = usage[:i] + name + usage[j+1:]
	return name, usage
	}
	}
	break
	}
	}
	return "", usage
	}

	func prefixedNames(names []string, placeholder string) string {
	var prefixed string
	for i, name := range names {
	if name == "" {
	continue
	}

	prefixed += prefixFor(name) + name
	if placeholder != "" {
	prefixed += " " + placeholder
	}
	if i < len(names)-1 {
	prefixed += ", "
	}
	}
	return prefixed
	}

	func envFormat(envVars []string, prefix, sep, suffix string) string {
	if len(envVars) > 0 {
	return fmt.Sprintf(" [%s%s%s]", prefix, strings.Join(envVars, sep), suffix)
	}
	return ""
	}

	func defaultEnvFormat(envVars []string) string {
	return envFormat(envVars, "$", ", $", "")
	}

	func withEnvHint(envVars []string, str string) string {
	envText := ""
	if runtime.GOOS != "windows" \|\| os.Getenv("PSHOME") != "" {
	envText = defaultEnvFormat(envVars)
	} else {
	envText = envFormat(envVars, "%", "%, %", "%")
	}
	return str + envText
	}

	func FlagNames(name string, aliases []string) []string {
	var ret []string

	for _, part := range append([]string{name}, aliases...) {
	// v1 -> v2 migration warning zone:
	// Strip off anything after the first found comma or space, which
	// hopefully makes it a tiny bit more obvious that unexpected behavior is
	// caused by using the v1 form of stringly typed "Name".
	ret = append(ret, commaWhitespace.ReplaceAllString(part, ""))
	}

	return ret
	}

	func withFileHint(filePath, str string) string {
	fileText := ""
	if filePath != "" {
	fileText = fmt.Sprintf(" [%s]", filePath)
	}
	return str + fileText
	}

	func formatDefault(format string) string {
	return " (default: " + format + ")"
	}

	func stringifyFlag(f Flag) string {
	// enforce DocGeneration interface on flags to avoid reflection
	df, ok := f.(DocGenerationFlag)
	if !ok {
	return ""
	}

	placeholder, usage := unquoteUsage(df.GetUsage())
	needsPlaceholder := df.TakesValue()

	if needsPlaceholder && placeholder == "" {
	placeholder = defaultPlaceholder
	}

	defaultValueString := ""

	// set default text for all flags except bool flags
	// for bool flags display default text if DisableDefaultText is not
	// set
	if bf, ok := f.(*BoolFlag); !ok \|\| !bf.DisableDefaultText {
	if s := df.GetDefaultText(); s != "" {
	defaultValueString = fmt.Sprintf(formatDefault("%s"), s)
	}
	}

	usageWithDefault := strings.TrimSpace(usage + defaultValueString)

	pn := prefixedNames(df.Names(), placeholder)
	sliceFlag, ok := f.(DocGenerationSliceFlag)
	if ok && sliceFlag.IsSliceFlag() {
	pn = pn + " [ " + pn + " ]"
	}

	return withEnvHint(df.GetEnvVars(), fmt.Sprintf("%s\t%s", pn, usageWithDefault))
	}

	func hasFlag(flags []Flag, fl Flag) bool {
	for _, existing := range flags {
	if fl == existing {
	return true
	}
	}

	return false
	}

	// Return the first value from a list of environment variables and files
	// (which may or may not exist), a description of where the value was found,
	// and a boolean which is true if a value was found.
	func flagFromEnvOrFile(envVars []string, filePath string) (value string, fromWhere string, found bool) {
	for _, envVar := range envVars {
	envVar = strings.TrimSpace(envVar)
	if value, found := syscall.Getenv(envVar); found {
	return value, fmt.Sprintf("environment variable %q", envVar), true
	}
	}
	for _, fileVar := range strings.Split(filePath, ",") {
	if fileVar != "" {
	if data, err := os.ReadFile(fileVar); err == nil {
	return string(data), fmt.Sprintf("file %q", filePath), true
	}
	}
	}
	return "", "", false
	}

	type customizedSeparator interface {
	WithSeparatorSpec(separatorSpec)
	}

	type separatorSpec struct {
	sep string
	disabled bool
	customized bool
	}

	func (s separatorSpec) flagSplitMultiValues(val string) []string {
	var (
	disabled bool = s.disabled
	sep string = s.sep
	)
	if !s.customized {
	disabled = disableSliceFlagSeparator
	sep = defaultSliceFlagSeparator
	}
	if disabled {
	return []string{val}
	}

	return strings.Split(val, sep)
	}