rpaste/vendor/github.com/urfave/cli/v2/flag.go

385 lines
9.2 KiB
Go

package cli
import (
"errors"
"flag"
"fmt"
"io/ioutil"
"os"
"regexp"
"runtime"
"strings"
"syscall"
"time"
)
const defaultPlaceholder = "value"
var defaultSliceFlagSeparator = ","
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",
}
// 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",
}
// 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) (*flag.FlagSet, error) {
set := flag.NewFlagSet(name, flag.ContinueOnError)
for _, f := range flags {
if err := f.Apply(set); err != nil {
return nil, err
}
}
set.SetOutput(ioutil.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 := ""
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 := ioutil.ReadFile(fileVar); err == nil {
return string(data), fmt.Sprintf("file %q", filePath), true
}
}
}
return "", "", false
}
func flagSplitMultiValues(val string) []string {
return strings.Split(val, defaultSliceFlagSeparator)
}