cobra/command.go
Eric Paris 9b2e6822e5 Add bash autocompletion generator
Given a (potentially annotated) cobra command you can generate a bash
completion script.
2015-04-07 20:13:49 -04:00

961 lines
23 KiB
Go

// Copyright © 2013 Steve Francia <spf@spf13.com>.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//Package cobra is a commander providing a simple interface to create powerful modern CLI interfaces.
//In addition to providing an interface, Cobra simultaneously provides a controller to organize your application code.
package cobra
import (
"bytes"
"fmt"
"github.com/inconshreveable/mousetrap"
flag "github.com/spf13/pflag"
"io"
"os"
"runtime"
"strings"
"time"
)
// Command is just that, a command for your application.
// eg. 'go run' ... 'run' is the command. Cobra requires
// you to define the usage and description as part of your command
// definition to ensure usability.
type Command struct {
// Name is the command name, usually the executable's name.
name string
// The one-line usage message.
Use string
// An array of aliases that can be used instead of the first word in Use.
Aliases []string
// The short description shown in the 'help' output.
Short string
// The long message shown in the 'help <this-command>' output.
Long string
// Examples of how to use the command
Example string
// List of all valid non-flag arguments, used for bash completions *TODO* actually validate these
ValidArgs []string
// Custom functions used by the bash autocompletion generator
BashCompletionFunction string
// Full set of flags
flags *flag.FlagSet
// Set of flags childrens of this command will inherit
pflags *flag.FlagSet
// Flags that are declared specifically by this command (not inherited).
lflags *flag.FlagSet
// Run runs the command.
// The args are the arguments after the command name.
Run func(cmd *Command, args []string)
// Commands is the list of commands supported by this program.
commands []*Command
// Parent Command for this command
parent *Command
// max lengths of commands' string lengths for use in padding
commandsMaxUseLen int
commandsMaxCommandPathLen int
commandsMaxNameLen int
flagErrorBuf *bytes.Buffer
cmdErrorBuf *bytes.Buffer
args []string // actual args parsed from flags
output *io.Writer // nil means stderr; use Out() method instead
usageFunc func(*Command) error // Usage can be defined by application
usageTemplate string // Can be defined by Application
helpTemplate string // Can be defined by Application
helpFunc func(*Command, []string) // Help can be defined by application
helpCommand *Command // The help command
helpFlagVal bool
}
// os.Args[1:] by default, if desired, can be overridden
// particularly useful when testing.
func (c *Command) SetArgs(a []string) {
c.args = a
}
func (c *Command) getOut(def io.Writer) io.Writer {
if c.output != nil {
return *c.output
}
if c.HasParent() {
return c.parent.Out()
} else {
return def
}
}
func (c *Command) Out() io.Writer {
return c.getOut(os.Stderr)
}
func (c *Command) getOutOrStdout() io.Writer {
return c.getOut(os.Stdout)
}
// SetOutput sets the destination for usage and error messages.
// If output is nil, os.Stderr is used.
func (c *Command) SetOutput(output io.Writer) {
c.output = &output
}
// Usage can be defined by application
func (c *Command) SetUsageFunc(f func(*Command) error) {
c.usageFunc = f
}
// Can be defined by Application
func (c *Command) SetUsageTemplate(s string) {
c.usageTemplate = s
}
// Can be defined by Application
func (c *Command) SetHelpFunc(f func(*Command, []string)) {
c.helpFunc = f
}
func (c *Command) SetHelpCommand(cmd *Command) {
c.helpCommand = cmd
}
// Can be defined by Application
func (c *Command) SetHelpTemplate(s string) {
c.helpTemplate = s
}
func (c *Command) UsageFunc() (f func(*Command) error) {
if c.usageFunc != nil {
return c.usageFunc
}
if c.HasParent() {
return c.parent.UsageFunc()
} else {
return func(c *Command) error {
err := tmpl(c.Out(), c.UsageTemplate(), c)
return err
}
}
}
func (c *Command) HelpFunc() func(*Command, []string) {
if c.helpFunc != nil {
return c.helpFunc
}
if c.HasParent() {
return c.parent.HelpFunc()
} else {
return func(c *Command, args []string) {
if len(args) == 0 {
// Help called without any topic, calling on root
c.Root().Help()
return
}
cmd, _, e := c.Root().Find(args)
if cmd == nil || e != nil {
c.Printf("Unknown help topic %#q.", args)
c.Root().Usage()
} else {
err := cmd.Help()
if err != nil {
c.Println(err)
}
}
}
}
}
var minUsagePadding int = 25
func (c *Command) UsagePadding() int {
if c.parent == nil || minUsagePadding > c.parent.commandsMaxUseLen {
return minUsagePadding
} else {
return c.parent.commandsMaxUseLen
}
}
var minCommandPathPadding int = 11
//
func (c *Command) CommandPathPadding() int {
if c.parent == nil || minCommandPathPadding > c.parent.commandsMaxCommandPathLen {
return minCommandPathPadding
} else {
return c.parent.commandsMaxCommandPathLen
}
}
var minNamePadding int = 11
func (c *Command) NamePadding() int {
if c.parent == nil || minNamePadding > c.parent.commandsMaxNameLen {
return minNamePadding
} else {
return c.parent.commandsMaxNameLen
}
}
func (c *Command) UsageTemplate() string {
if c.usageTemplate != "" {
return c.usageTemplate
}
if c.HasParent() {
return c.parent.UsageTemplate()
} else {
return `{{ $cmd := . }}
Usage: {{if .Runnable}}
{{.UseLine}}{{if .HasFlags}} [flags]{{end}}{{end}}{{if .HasSubCommands}}
{{ .CommandPath}} [command]{{end}}{{if gt .Aliases 0}}
Aliases:
{{.NameAndAliases}}
{{end}}{{if .HasExample}}
Examples:
{{ .Example }}
{{end}}{{ if .HasRunnableSubCommands}}
Available Commands: {{range .Commands}}{{if .Runnable}}
{{rpad .Name .NamePadding }} {{.Short}}{{end}}{{end}}
{{end}}
{{ if .HasLocalFlags}}Flags:
{{.LocalFlags.FlagUsages}}{{end}}
{{ if .HasInheritedFlags}}Global Flags:
{{.InheritedFlags.FlagUsages}}{{end}}{{if or (.HasHelpSubCommands) (.HasRunnableSiblings)}}
Additional help topics: {{if .HasHelpSubCommands}}{{range .Commands}}{{if not .Runnable}} {{rpad .CommandPath .CommandPathPadding}} {{.Short}}{{end}}{{end}}{{end}}{{if .HasRunnableSiblings }}{{range .Parent.Commands}}{{if .Runnable}}{{if not (eq .Name $cmd.Name) }}
{{rpad .CommandPath .CommandPathPadding}} {{.Short}}{{end}}{{end}}{{end}}{{end}}
{{end}}{{ if .HasSubCommands }}
Use "{{.Root.Name}} help [command]" for more information about a command.
{{end}}`
}
}
func (c *Command) HelpTemplate() string {
if c.helpTemplate != "" {
return c.helpTemplate
}
if c.HasParent() {
return c.parent.HelpTemplate()
} else {
return `{{with or .Long .Short }}{{. | trim}}{{end}}
{{if or .Runnable .HasSubCommands}}{{.UsageString}}{{end}}
`
}
}
// Really only used when casting a command to a commander
func (c *Command) resetChildrensParents() {
for _, x := range c.commands {
x.parent = c
}
}
// Test if the named flag is a boolean flag.
func isBooleanFlag(name string, f *flag.FlagSet) bool {
flag := f.Lookup(name)
if flag == nil {
return false
}
return flag.Value.Type() == "bool"
}
// Test if the named flag is a boolean flag.
func isBooleanShortFlag(name string, f *flag.FlagSet) bool {
result := false
f.VisitAll(func(f *flag.Flag) {
if f.Shorthand == name && f.Value.Type() == "bool" {
result = true
}
})
return result
}
func stripFlags(args []string, c *Command) []string {
if len(args) < 1 {
return args
}
c.mergePersistentFlags()
commands := []string{}
inQuote := false
inFlag := false
for _, y := range args {
if !inQuote {
switch {
case strings.HasPrefix(y, "\""):
inQuote = true
case strings.Contains(y, "=\""):
inQuote = true
case strings.HasPrefix(y, "--") && !strings.Contains(y, "="):
// TODO: this isn't quite right, we should really check ahead for 'true' or 'false'
inFlag = !isBooleanFlag(y[2:], c.Flags())
case strings.HasPrefix(y, "-") && !strings.Contains(y, "=") && len(y) == 2 && !isBooleanShortFlag(y[1:], c.Flags()):
inFlag = true
case inFlag:
inFlag = false
case y == "":
// strip empty commands, as the go tests expect this to be ok....
case !strings.HasPrefix(y, "-"):
commands = append(commands, y)
inFlag = false
}
}
if strings.HasSuffix(y, "\"") && !strings.HasSuffix(y, "\\\"") {
inQuote = false
}
}
return commands
}
func argsMinusX(args []string, x string) []string {
newargs := []string{}
for _, y := range args {
if x != y {
newargs = append(newargs, y)
}
}
return newargs
}
// find the target command given the args and command tree
// Meant to be run on the highest node. Only searches down.
func (c *Command) Find(arrs []string) (*Command, []string, error) {
if c == nil {
return nil, nil, fmt.Errorf("Called find() on a nil Command")
}
if len(arrs) == 0 {
return c.Root(), arrs, nil
}
var innerfind func(*Command, []string) (*Command, []string)
innerfind = func(c *Command, args []string) (*Command, []string) {
if len(args) > 0 && c.HasSubCommands() {
argsWOflags := stripFlags(args, c)
if len(argsWOflags) > 0 {
matches := make([]*Command, 0)
for _, cmd := range c.commands {
if cmd.Name() == argsWOflags[0] || cmd.HasAlias(argsWOflags[0]) { // exact name or alias match
return innerfind(cmd, argsMinusX(args, argsWOflags[0]))
} else if EnablePrefixMatching {
if strings.HasPrefix(cmd.Name(), argsWOflags[0]) { // prefix match
matches = append(matches, cmd)
}
for _, x := range cmd.Aliases {
if strings.HasPrefix(x, argsWOflags[0]) {
matches = append(matches, cmd)
}
}
}
}
// only accept a single prefix match - multiple matches would be ambiguous
if len(matches) == 1 {
return innerfind(matches[0], argsMinusX(args, argsWOflags[0]))
}
}
}
return c, args
}
commandFound, a := innerfind(c, arrs)
// If we matched on the root, but we asked for a subcommand, return an error
if commandFound.Name() == c.Name() && len(stripFlags(arrs, c)) > 0 && commandFound.Name() != arrs[0] {
return nil, a, fmt.Errorf("unknown command %q", a[0])
}
return commandFound, a, nil
}
func (c *Command) Root() *Command {
var findRoot func(*Command) *Command
findRoot = func(x *Command) *Command {
if x.HasParent() {
return findRoot(x.parent)
} else {
return x
}
}
return findRoot(c)
}
func (c *Command) execute(a []string) (err error) {
if c == nil {
return fmt.Errorf("Called Execute() on a nil Command")
}
err = c.ParseFlags(a)
if err == flag.ErrHelp {
c.Help()
return nil
}
if err != nil {
// We're writing subcommand usage to root command's error buffer to have it displayed to the user
r := c.Root()
if r.cmdErrorBuf == nil {
r.cmdErrorBuf = new(bytes.Buffer)
}
// for writing the usage to the buffer we need to switch the output temporarily
// since Out() returns root output, you also need to revert that on root
out := r.Out()
r.SetOutput(r.cmdErrorBuf)
c.Usage()
r.SetOutput(out)
return err
} else {
// If help is called, regardless of other flags, we print that.
// Print help also if c.Run is nil.
if c.helpFlagVal || !c.Runnable() {
c.Help()
return nil
}
c.preRun()
argWoFlags := c.Flags().Args()
c.Run(c, argWoFlags)
return nil
}
}
func (c *Command) preRun() {
for _, x := range initializers {
x()
}
}
func (c *Command) errorMsgFromParse() string {
s := c.flagErrorBuf.String()
x := strings.Split(s, "\n")
if len(x) > 0 {
return x[0]
} else {
return ""
}
}
// Call execute to use the args (os.Args[1:] by default)
// and run through the command tree finding appropriate matches
// for commands and then corresponding flags.
func (c *Command) Execute() (err error) {
// Regardless of what command execute is called on, run on Root only
if c.HasParent() {
return c.Root().Execute()
}
if EnableWindowsMouseTrap && runtime.GOOS == "windows" {
if mousetrap.StartedByExplorer() {
c.Print(MousetrapHelpText)
time.Sleep(5 * time.Second)
os.Exit(1)
}
}
// initialize help as the last point possible to allow for user
// overriding
c.initHelp()
var args []string
if len(c.args) == 0 {
args = os.Args[1:]
} else {
args = c.args
}
if len(args) == 0 {
// Only the executable is called and the root is runnable, run it
if c.Runnable() {
err = c.execute([]string(nil))
} else {
c.Help()
}
} else {
cmd, flags, e := c.Find(args)
if e != nil {
err = e
} else {
err = cmd.execute(flags)
}
}
if err != nil {
if err == flag.ErrHelp {
c.Help()
} else {
c.Println("Error:", err.Error())
c.Printf("Run '%v help' for usage.\n", c.Root().Name())
}
}
return
}
func (c *Command) initHelp() {
if c.helpCommand == nil {
if !c.HasSubCommands() {
return
}
c.helpCommand = &Command{
Use: "help [command]",
Short: "Help about any command",
Long: `Help provides help for any command in the application.
Simply type ` + c.Name() + ` help [path to command] for full details.`,
Run: c.HelpFunc(),
}
}
c.AddCommand(c.helpCommand)
}
// Used for testing
func (c *Command) ResetCommands() {
c.commands = nil
c.helpCommand = nil
c.cmdErrorBuf = new(bytes.Buffer)
c.cmdErrorBuf.Reset()
}
//Commands returns a slice of child commands.
func (c *Command) Commands() []*Command {
return c.commands
}
// AddCommand adds one or more commands to this parent command.
func (c *Command) AddCommand(cmds ...*Command) {
for i, x := range cmds {
if cmds[i] == c {
panic("Command can't be a child of itself")
}
cmds[i].parent = c
// update max lengths
usageLen := len(x.Use)
if usageLen > c.commandsMaxUseLen {
c.commandsMaxUseLen = usageLen
}
commandPathLen := len(x.CommandPath())
if commandPathLen > c.commandsMaxCommandPathLen {
c.commandsMaxCommandPathLen = commandPathLen
}
nameLen := len(x.Name())
if nameLen > c.commandsMaxNameLen {
c.commandsMaxNameLen = nameLen
}
c.commands = append(c.commands, x)
}
}
// AddCommand removes one or more commands from a parent command.
func (c *Command) RemoveCommand(cmds ...*Command) {
commands := []*Command{}
main:
for _, command := range c.commands {
for _, cmd := range cmds {
if command == cmd {
command.parent = nil
continue main
}
}
commands = append(commands, command)
}
c.commands = commands
// recompute all lengths
c.commandsMaxUseLen = 0
c.commandsMaxCommandPathLen = 0
c.commandsMaxNameLen = 0
for _, command := range c.commands {
usageLen := len(command.Use)
if usageLen > c.commandsMaxUseLen {
c.commandsMaxUseLen = usageLen
}
commandPathLen := len(command.CommandPath())
if commandPathLen > c.commandsMaxCommandPathLen {
c.commandsMaxCommandPathLen = commandPathLen
}
nameLen := len(command.Name())
if nameLen > c.commandsMaxNameLen {
c.commandsMaxNameLen = nameLen
}
}
}
// Convenience method to Print to the defined output
func (c *Command) Print(i ...interface{}) {
fmt.Fprint(c.Out(), i...)
}
// Convenience method to Println to the defined output
func (c *Command) Println(i ...interface{}) {
str := fmt.Sprintln(i...)
c.Print(str)
}
// Convenience method to Printf to the defined output
func (c *Command) Printf(format string, i ...interface{}) {
str := fmt.Sprintf(format, i...)
c.Print(str)
}
// Output the usage for the command
// Used when a user provides invalid input
// Can be defined by user by overriding UsageFunc
func (c *Command) Usage() error {
c.mergePersistentFlags()
err := c.UsageFunc()(c)
return err
}
// Output the help for the command
// Used when a user calls help [command]
// by the default HelpFunc in the commander
func (c *Command) Help() error {
c.mergePersistentFlags()
err := tmpl(c.getOutOrStdout(), c.HelpTemplate(), c)
return err
}
func (c *Command) UsageString() string {
tmpOutput := c.output
bb := new(bytes.Buffer)
c.SetOutput(bb)
c.Usage()
c.output = tmpOutput
return bb.String()
}
// CommandPath returns the full path to this command.
func (c *Command) CommandPath() string {
str := c.Name()
x := c
for x.HasParent() {
str = x.parent.Name() + " " + str
x = x.parent
}
return str
}
//The full usage for a given command (including parents)
func (c *Command) UseLine() string {
str := ""
if c.HasParent() {
str = c.parent.CommandPath() + " "
}
return str + c.Use
}
// For use in determining which flags have been assigned to which commands
// and which persist
func (c *Command) DebugFlags() {
c.Println("DebugFlags called on", c.Name())
var debugflags func(*Command)
debugflags = func(x *Command) {
if x.HasFlags() || x.HasPersistentFlags() {
c.Println(x.Name())
}
if x.HasFlags() {
x.flags.VisitAll(func(f *flag.Flag) {
if x.HasPersistentFlags() {
if x.persistentFlag(f.Name) == nil {
c.Println(" -"+f.Shorthand+",", "--"+f.Name, "["+f.DefValue+"]", "", f.Value, " [L]")
} else {
c.Println(" -"+f.Shorthand+",", "--"+f.Name, "["+f.DefValue+"]", "", f.Value, " [LP]")
}
} else {
c.Println(" -"+f.Shorthand+",", "--"+f.Name, "["+f.DefValue+"]", "", f.Value, " [L]")
}
})
}
if x.HasPersistentFlags() {
x.pflags.VisitAll(func(f *flag.Flag) {
if x.HasFlags() {
if x.flags.Lookup(f.Name) == nil {
c.Println(" -"+f.Shorthand+",", "--"+f.Name, "["+f.DefValue+"]", "", f.Value, " [P]")
}
} else {
c.Println(" -"+f.Shorthand+",", "--"+f.Name, "["+f.DefValue+"]", "", f.Value, " [P]")
}
})
}
c.Println(x.flagErrorBuf)
if x.HasSubCommands() {
for _, y := range x.commands {
debugflags(y)
}
}
}
debugflags(c)
}
// Name returns the command's name: the first word in the use line.
func (c *Command) Name() string {
if c.name != "" {
return c.name
}
name := c.Use
i := strings.Index(name, " ")
if i >= 0 {
name = name[:i]
}
return name
}
// Determine if a given string is an alias of the command.
func (c *Command) HasAlias(s string) bool {
for _, a := range c.Aliases {
if a == s {
return true
}
}
return false
}
func (c *Command) NameAndAliases() string {
return strings.Join(append([]string{c.Name()}, c.Aliases...), ", ")
}
func (c *Command) HasExample() bool {
return len(c.Example) > 0
}
// Determine if the command is itself runnable
func (c *Command) Runnable() bool {
return c.Run != nil
}
// Determine if the command has children commands
func (c *Command) HasSubCommands() bool {
return len(c.commands) > 0
}
func (c *Command) HasRunnableSiblings() bool {
if !c.HasParent() {
return false
}
for _, sub := range c.parent.commands {
if sub.Runnable() {
return true
}
}
return false
}
func (c *Command) HasHelpSubCommands() bool {
for _, sub := range c.commands {
if !sub.Runnable() {
return true
}
}
return false
}
// Determine if the command has runnable children commands
func (c *Command) HasRunnableSubCommands() bool {
for _, sub := range c.commands {
if sub.Runnable() {
return true
}
}
return false
}
// Determine if the command is a child command
func (c *Command) HasParent() bool {
return c.parent != nil
}
// Get the complete FlagSet that applies to this command (local and persistent declared here and by all parents)
func (c *Command) Flags() *flag.FlagSet {
if c.flags == nil {
c.flags = flag.NewFlagSet(c.Name(), flag.ContinueOnError)
if c.flagErrorBuf == nil {
c.flagErrorBuf = new(bytes.Buffer)
}
c.flags.SetOutput(c.flagErrorBuf)
c.PersistentFlags().BoolVarP(&c.helpFlagVal, "help", "h", false, "help for "+c.Name())
}
return c.flags
}
// Get the local FlagSet specifically set in the current command
func (c *Command) LocalFlags() *flag.FlagSet {
c.mergePersistentFlags()
local := flag.NewFlagSet(c.Name(), flag.ContinueOnError)
c.lflags.VisitAll(func(f *flag.Flag) {
local.AddFlag(f)
})
return local
}
// All Flags which were inherited from parents commands
func (c *Command) InheritedFlags() *flag.FlagSet {
c.mergePersistentFlags()
inherited := flag.NewFlagSet(c.Name(), flag.ContinueOnError)
local := c.LocalFlags()
var rmerge func(x *Command)
rmerge = func(x *Command) {
if x.HasPersistentFlags() {
x.PersistentFlags().VisitAll(func(f *flag.Flag) {
if inherited.Lookup(f.Name) == nil && local.Lookup(f.Name) == nil {
inherited.AddFlag(f)
}
})
}
if x.HasParent() {
rmerge(x.parent)
}
}
if c.HasParent() {
rmerge(c.parent)
}
return inherited
}
// All Flags which were not inherited from parent commands
func (c *Command) NonInheritedFlags() *flag.FlagSet {
return c.LocalFlags()
}
// Get the Persistent FlagSet specifically set in the current command
func (c *Command) PersistentFlags() *flag.FlagSet {
if c.pflags == nil {
c.pflags = flag.NewFlagSet(c.Name(), flag.ContinueOnError)
if c.flagErrorBuf == nil {
c.flagErrorBuf = new(bytes.Buffer)
}
c.pflags.SetOutput(c.flagErrorBuf)
}
return c.pflags
}
// For use in testing
func (c *Command) ResetFlags() {
c.flagErrorBuf = new(bytes.Buffer)
c.flagErrorBuf.Reset()
c.flags = flag.NewFlagSet(c.Name(), flag.ContinueOnError)
c.flags.SetOutput(c.flagErrorBuf)
c.pflags = flag.NewFlagSet(c.Name(), flag.ContinueOnError)
c.pflags.SetOutput(c.flagErrorBuf)
}
// Does the command contain any flags (local plus persistent from the entire structure)
func (c *Command) HasFlags() bool {
return c.Flags().HasFlags()
}
// Does the command contain persistent flags
func (c *Command) HasPersistentFlags() bool {
return c.PersistentFlags().HasFlags()
}
// Does the command has flags specifically declared locally
func (c *Command) HasLocalFlags() bool {
return c.LocalFlags().HasFlags()
}
func (c *Command) HasInheritedFlags() bool {
return c.InheritedFlags().HasFlags()
}
// Climbs up the command tree looking for matching flag
func (c *Command) Flag(name string) (flag *flag.Flag) {
flag = c.Flags().Lookup(name)
if flag == nil {
flag = c.persistentFlag(name)
}
return
}
// recursively find matching persistent flag
func (c *Command) persistentFlag(name string) (flag *flag.Flag) {
if c.HasPersistentFlags() {
flag = c.PersistentFlags().Lookup(name)
}
if flag == nil && c.HasParent() {
flag = c.parent.persistentFlag(name)
}
return
}
// Parses persistent flag tree & local flags
func (c *Command) ParseFlags(args []string) (err error) {
c.mergePersistentFlags()
err = c.Flags().Parse(args)
return
}
func (c *Command) Parent() *Command {
return c.parent
}
func (c *Command) mergePersistentFlags() {
var rmerge func(x *Command)
// Save the set of local flags
if c.lflags == nil {
c.lflags = flag.NewFlagSet(c.Name(), flag.ContinueOnError)
if c.flagErrorBuf == nil {
c.flagErrorBuf = new(bytes.Buffer)
}
c.lflags.SetOutput(c.flagErrorBuf)
addtolocal := func(f *flag.Flag) {
c.lflags.AddFlag(f)
}
c.Flags().VisitAll(addtolocal)
c.PersistentFlags().VisitAll(addtolocal)
}
rmerge = func(x *Command) {
if x.HasPersistentFlags() {
x.PersistentFlags().VisitAll(func(f *flag.Flag) {
if c.Flags().Lookup(f.Name) == nil {
c.Flags().AddFlag(f)
}
})
}
if x.HasParent() {
rmerge(x.parent)
}
}
rmerge(c)
}