var AppHelpTemplate = `NAME:
{{.Name}} - {{.Usage}}
USAGE:
{{if .UsageText}}{{.UsageText}}{{else}}{{.HelpName}} {{if .VisibleFlags}}[global options]{{end}}{{if .Commands}} command [command options]{{end}} {{if .ArgsUsage}}{{.ArgsUsage}}{{else}}[arguments...]{{end}}{{end}}
{{if .Version}}{{if not .HideVersion}}
VERSION:
{{.Version}}
{{end}}{{end}}{{if len .Authors}}
AUTHOR(S):
{{range .Authors}}{{.}}{{end}}
{{end}}{{if .VisibleCommands}}
COMMANDS:{{range .VisibleCategories}}{{if .Name}}
{{.Name}}:{{end}}{{range .VisibleCommands}}
{{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}
{{end}}{{end}}{{if .VisibleFlags}}
GLOBAL OPTIONS:
{{range .VisibleFlags}}{{.}}
{{end}}{{end}}{{if .Copyright}}
COPYRIGHT:
{{.Copyright}}
{{end}}
`
AppHelpTemplate is the text template for the Default help topic. cli.go uses text/template to render templates. You can render custom help text by setting this variable.
var BashCompletionFlag = BoolFlag{ Name: "generate-bash-completion", Hidden: true, }
BashCompletionFlag enables bash-completion for all commands and subcommands
var CommandHelpTemplate = `NAME:
{{.HelpName}} - {{.Usage}}
USAGE:
{{.HelpName}}{{if .VisibleFlags}} [command options]{{end}} {{if .ArgsUsage}}{{.ArgsUsage}}{{else}}[arguments...]{{end}}{{if .Category}}
CATEGORY:
{{.Category}}{{end}}{{if .Description}}
DESCRIPTION:
{{.Description}}{{end}}{{if .VisibleFlags}}
OPTIONS:
{{range .VisibleFlags}}{{.}}
{{end}}{{end}}
`
CommandHelpTemplate is the text template for the command help topic. cli.go uses text/template to render templates. You can render custom help text by setting this variable.
var ErrWriter io.Writer = os.Stderr
ErrWriter is used to write errors to the user. This can be anything implementing the io.Writer interface and defaults to os.Stderr.
var HelpFlag = BoolFlag{ Name: "help, h", Usage: "show help", }
HelpFlag prints the help for all commands and subcommands Set to the zero value (BoolFlag{}) to disable flag -- keeps subcommand unless HideHelp is set to true)
var HelpPrinter helpPrinter = printHelp
HelpPrinter is a function that writes the help output. If not set a default is used. The function signature is: func(w io.Writer, templ string, data interface{})
var OsExiter = os.Exit
OsExiter is the function used when the app exits. If not set defaults to os.Exit.
var SubcommandHelpTemplate = `NAME:
{{.HelpName}} - {{.Usage}}
USAGE:
{{.HelpName}} command{{if .VisibleFlags}} [command options]{{end}} {{if .ArgsUsage}}{{.ArgsUsage}}{{else}}[arguments...]{{end}}
COMMANDS:{{range .VisibleCategories}}{{if .Name}}
{{.Name}}:{{end}}{{range .VisibleCommands}}
{{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}
{{end}}{{if .VisibleFlags}}
OPTIONS:
{{range .VisibleFlags}}{{.}}
{{end}}{{end}}
`
SubcommandHelpTemplate is the text template for the subcommand help topic. cli.go uses text/template to render templates. You can render custom help text by setting this variable.
var VersionFlag = BoolFlag{ Name: "version, v", Usage: "print the version", }
VersionFlag prints the version for the application
var VersionPrinter = printVersion
VersionPrinter prints the version for the App
func DefaultAppComplete(c *Context)
DefaultAppComplete prints the list of subcommands as the default app completion method
func HandleAction(action interface{}, context *Context) (err error)
HandleAction uses ✧✧✧reflection✧✧✧ to figure out if the given Action is an ActionFunc, a func with the legacy signature for Action, or some other invalid thing. If it's an ActionFunc or a func with the legacy signature for Action, the func is run!
func HandleExitCoder(err error)
HandleExitCoder checks if the error fulfills the ExitCoder interface, and if so prints the error to stderr (if it is non-empty) and calls OsExiter with the given exit code. If the given error is a MultiError, then this func is called on all members of the Errors slice.
func ShowAppHelp(c *Context) error
ShowAppHelp is an action that displays the help.
func ShowCommandCompletions(ctx *Context, command string)
ShowCommandCompletions prints the custom completions for a given command
func ShowCommandHelp(ctx *Context, command string) error
ShowCommandHelp prints help for the given command
func ShowCompletions(c *Context)
ShowCompletions prints the lists of commands within a given context
func ShowSubcommandHelp(c *Context) error
ShowSubcommandHelp prints help for the given subcommand
func ShowVersion(c *Context)
ShowVersion prints the version number of the App
type ActionFunc func(*Context) error
ActionFunc is the action to execute when no subcommands are specified
type AfterFunc func(*Context) error
AfterFunc is an action to execute after any subcommands are run, but after the subcommand has finished it is run even if Action() panics
type App struct {
// The name of the program. Defaults to path.Base(os.Args[0])
Name string
// Full name of command for help, defaults to Name
HelpName string
// Description of the program.
Usage string
// Text to override the USAGE section of help
UsageText string
// Description of the program argument format.
ArgsUsage string
// Version of the program
Version string
// List of commands to execute
Commands []Command
// List of flags to parse
Flags []Flag
// Boolean to enable bash completion commands
EnableBashCompletion bool
// Boolean to hide built-in help command
HideHelp bool
// Boolean to hide built-in version flag and the VERSION section of help
HideVersion bool
// An action to execute when the bash-completion flag is set
BashComplete BashCompleteFunc
// An action to execute before any subcommands are run, but after the context is ready
// If a non-nil error is returned, no subcommands are run
Before BeforeFunc
// An action to execute after any subcommands are run, but after the subcommand has finished
// It is run even if Action() panics
After AfterFunc
// The action to execute when no subcommands are specified
// Expects a `cli.ActionFunc` but will accept the *deprecated* signature of `func(*cli.Context) {}`
// *Note*: support for the deprecated `Action` signature will be removed in a future version
Action interface{}
// Execute this function if the proper command cannot be found
CommandNotFound CommandNotFoundFunc
// Execute this function if an usage error occurs
OnUsageError OnUsageErrorFunc
// Compilation date
Compiled time.Time
// List of all authors who contributed
Authors []Author
// Copyright of the binary if any
Copyright string
// Name of Author (Note: Use App.Authors, this is deprecated)
Author string
// Email of Author (Note: Use App.Authors, this is deprecated)
Email string
// Writer writer to write output to
Writer io.Writer
// ErrWriter writes error output
ErrWriter io.Writer
// Other custom info
Metadata map[string]interface{}
// contains filtered or unexported fields
}
App is the main structure of a cli application. It is recommended that an app be created with the cli.NewApp() function
func NewApp() *App
NewApp creates a new cli Application with some reasonable defaults for Name, Usage, Version and Action.
func (a *App) Categories() CommandCategories
Categories returns a slice containing all the categories with the commands they contain
func (a *App) Command(name string) *Command
Command returns the named command on App. Returns nil if the command does not exist
func (a *App) Run(arguments []string) (err error)
Run is the entry point to the cli app. Parses the arguments slice and routes to the proper flag/args combination
▹ Example
▹ Example (BashComplete)
▹ Example (Help)
▹ Example (Subcommand)
func (a *App) RunAndExitOnError()
RunAndExitOnError calls .Run() and exits non-zero if an error was returned
Deprecated: instead you should return an error that fulfills cli.ExitCoder to cli.App.Run. This will cause the application to exit with the given eror code in the cli.ExitCoder
func (a *App) RunAsSubcommand(ctx *Context) (err error)
RunAsSubcommand invokes the subcommand given the context, parses ctx.Args() to generate command-specific flags
func (a *App) Setup()
Setup runs initialization code to ensure all data structures are ready for `Run` or inspection prior to `Run`. It is internally called by `Run`, but will return early if setup has already happened.
func (a *App) VisibleCategories() []*CommandCategory
VisibleCategories returns a slice of categories and commands that are Hidden=false
func (a *App) VisibleCommands() []Command
VisibleCommands returns a slice of the Commands with Hidden=false
func (a *App) VisibleFlags() []Flag
VisibleFlags returns a slice of the Flags with Hidden=false
type Args []string
Args contains apps console arguments
func (a Args) First() string
First returns the first argument, or else a blank string
func (a Args) Get(n int) string
Get returns the nth argument, or else a blank string
func (a Args) Present() bool
Present checks if there are any arguments present
func (a Args) Swap(from, to int) error
Swap swaps arguments at the given indexes
func (a Args) Tail() []string
Tail returns the rest of the arguments (not the first one) or else an empty string slice
type Author struct {
Name string // The Authors name
Email string // The Authors email
}
Author represents someone who has contributed to a cli project.
func (a Author) String() string
String makes Author comply to the Stringer interface, to allow an easy print in the templating process
type BashCompleteFunc func(*Context)
BashCompleteFunc is an action to execute when the bash-completion flag is set
type BeforeFunc func(*Context) error
BeforeFunc is an action to execute before any subcommands are run, but after the context is ready if a non-nil error is returned, no subcommands are run
type BoolFlag struct {
Name string
Usage string
EnvVar string
Hidden bool
Destination *bool
}
BoolFlag is a flag with type bool
func (f BoolFlag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment
func (f BoolFlag) GetName() string
GetName returns the name of the flag
func (f BoolFlag) String() string
String returns a readable representation of this value (for usage defaults)
type BoolTFlag struct {
Name string
Usage string
EnvVar string
Hidden bool
Destination *bool
}
BoolTFlag is a flag with type bool that is true by default
func (f BoolTFlag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment
func (f BoolTFlag) GetName() string
GetName returns the name of the flag
func (f BoolTFlag) String() string
String returns a readable representation of this value (for usage defaults)
type Command struct {
// The name of the command
Name string
// short name of the command. Typically one character (deprecated, use `Aliases`)
ShortName string
// A list of aliases for the command
Aliases []string
// A short description of the usage of this command
Usage string
// Custom text to show on USAGE section of help
UsageText string
// A longer explanation of how the command works
Description string
// A short description of the arguments of this command
ArgsUsage string
// The category the command is part of
Category string
// The function to call when checking for bash command completions
BashComplete BashCompleteFunc
// An action to execute before any sub-subcommands are run, but after the context is ready
// If a non-nil error is returned, no sub-subcommands are run
Before BeforeFunc
// An action to execute after any subcommands are run, but after the subcommand has finished
// It is run even if Action() panics
After AfterFunc
// The function to call when this command is invoked
Action interface{}
// Execute this function if a usage error occurs.
OnUsageError OnUsageErrorFunc
// List of child commands
Subcommands Commands
// List of flags to parse
Flags []Flag
// Treat all flags as normal arguments if true
SkipFlagParsing bool
// Skip argument reordering which attempts to move flags before arguments,
// but only works if all flags appear after all arguments. This behavior was
// removed n version 2 since it only works under specific conditions so we
// backport here by exposing it as an option for compatibility.
SkipArgReorder bool
// Boolean to hide built-in help command
HideHelp bool
// Boolean to hide this command from help or completion
Hidden bool
// Full name of command for help, defaults to full command name, including parent commands.
HelpName string
// contains filtered or unexported fields
}
Command is a subcommand for a cli.App.
func (c Command) FullName() string
FullName returns the full name of the command. For subcommands this ensures that parent commands are part of the command path
func (c Command) HasName(name string) bool
HasName returns true if Command.Name or Command.ShortName matches given name
func (c Command) Names() []string
Names returns the names including short names and aliases.
func (c Command) Run(ctx *Context) (err error)
Run invokes the command given the context, parses ctx.Args() to generate command-specific flags
func (c Command) VisibleFlags() []Flag
VisibleFlags returns a slice of the Flags with Hidden=false
type CommandCategories []*CommandCategory
CommandCategories is a slice of *CommandCategory.
func (c CommandCategories) AddCommand(category string, command Command) CommandCategories
AddCommand adds a command to a category.
func (c CommandCategories) Len() int
func (c CommandCategories) Less(i, j int) bool
func (c CommandCategories) Swap(i, j int)
type CommandCategory struct {
Name string
Commands Commands
}
CommandCategory is a category containing commands.
func (c *CommandCategory) VisibleCommands() []Command
VisibleCommands returns a slice of the Commands with Hidden=false
type CommandNotFoundFunc func(*Context, string)
CommandNotFoundFunc is executed if the proper command cannot be found
type Commands []Command
Commands is a slice of Command
type Context struct {
App *App
Command Command
// contains filtered or unexported fields
}
Context is a type that is passed through to each Handler action in a cli application. Context can be used to retrieve context-specific Args and parsed command-line options.
func NewContext(app *App, set *flag.FlagSet, parentCtx *Context) *Context
NewContext creates a new context. For use in when invoking an App or Command action.
func (c *Context) Args() Args
Args returns the command line arguments associated with the context.
func (c *Context) Bool(name string) bool
Bool looks up the value of a local BoolFlag, returns false if not found
func (c *Context) BoolT(name string) bool
BoolT looks up the value of a local BoolTFlag, returns false if not found
func (c *Context) Duration(name string) time.Duration
Duration looks up the value of a local DurationFlag, returns 0 if not found
func (c *Context) FlagNames() (names []string)
FlagNames returns a slice of flag names used in this context.
func (c *Context) Float64(name string) float64
Float64 looks up the value of a local Float64Flag, returns 0 if not found
func (c *Context) Generic(name string) interface{}
Generic looks up the value of a local GenericFlag, returns nil if not found
func (c *Context) GlobalBool(name string) bool
GlobalBool looks up the value of a global BoolFlag, returns false if not found
func (c *Context) GlobalBoolT(name string) bool
GlobalBoolT looks up the value of a global BoolTFlag, returns false if not found
func (c *Context) GlobalDuration(name string) time.Duration
GlobalDuration looks up the value of a global DurationFlag, returns 0 if not found
func (c *Context) GlobalFlagNames() (names []string)
GlobalFlagNames returns a slice of global flag names used by the app.
func (c *Context) GlobalFloat64(name string) float64
GlobalFloat64 looks up the value of a global Float64Flag, returns 0 if not found
func (c *Context) GlobalGeneric(name string) interface{}
GlobalGeneric looks up the value of a global GenericFlag, returns nil if not found
func (c *Context) GlobalInt(name string) int
GlobalInt looks up the value of a global IntFlag, returns 0 if not found
func (c *Context) GlobalInt64(name string) int64
GlobalInt64 looks up the value of a global Int64Flag, returns 0 if not found
func (c *Context) GlobalInt64Slice(name string) []int64
GlobalInt64Slice looks up the value of a global Int64SliceFlag, returns nil if not found
func (c *Context) GlobalIntSlice(name string) []int
GlobalIntSlice looks up the value of a global IntSliceFlag, returns nil if not found
func (c *Context) GlobalIsSet(name string) bool
GlobalIsSet determines if the global flag was actually set
func (c *Context) GlobalSet(name, value string) error
GlobalSet sets a context flag to a value on the global flagset
func (c *Context) GlobalString(name string) string
GlobalString looks up the value of a global StringFlag, returns "" if not found
func (c *Context) GlobalStringSlice(name string) []string
GlobalStringSlice looks up the value of a global StringSliceFlag, returns nil if not found
func (c *Context) GlobalUint(name string) uint
GlobalUint looks up the value of a global UintFlag, returns 0 if not found
func (c *Context) GlobalUint64(name string) uint64
GlobalUint64 looks up the value of a global Uint64Flag, returns 0 if not found
func (c *Context) Int(name string) int
Int looks up the value of a local IntFlag, returns 0 if not found
func (c *Context) Int64(name string) int64
Int64 looks up the value of a local Int64Flag, returns 0 if not found
func (c *Context) Int64Slice(name string) []int64
Int64Slice looks up the value of a local Int64SliceFlag, returns nil if not found
func (c *Context) IntSlice(name string) []int
IntSlice looks up the value of a local IntSliceFlag, returns nil if not found
func (c *Context) IsSet(name string) bool
IsSet determines if the flag was actually set
func (c *Context) NArg() int
NArg returns the number of the command line arguments.
func (c *Context) NumFlags() int
NumFlags returns the number of flags set
func (c *Context) Parent() *Context
Parent returns the parent context, if any
func (c *Context) Set(name, value string) error
Set sets a context flag to a value.
func (c *Context) String(name string) string
String looks up the value of a local StringFlag, returns "" if not found
func (c *Context) StringSlice(name string) []string
StringSlice looks up the value of a local StringSliceFlag, returns nil if not found
func (c *Context) Uint(name string) uint
Uint looks up the value of a local UintFlag, returns 0 if not found
func (c *Context) Uint64(name string) uint64
Uint64 looks up the value of a local Uint64Flag, returns 0 if not found
type DurationFlag struct {
Name string
Usage string
EnvVar string
Hidden bool
Value time.Duration
Destination *time.Duration
}
DurationFlag is a flag with type time.Duration (see https://golang.org/pkg/time/#ParseDuration)
func (f DurationFlag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment
func (f DurationFlag) GetName() string
GetName returns the name of the flag
func (f DurationFlag) String() string
String returns a readable representation of this value (for usage defaults)
type ExitCoder interface {
error
ExitCode() int
}
ExitCoder is the interface checked by `App` and `Command` for a custom exit code
type ExitError struct {
// contains filtered or unexported fields
}
ExitError fulfills both the builtin `error` interface and `ExitCoder`
func NewExitError(message string, exitCode int) *ExitError
NewExitError makes a new *ExitError
func (ee *ExitError) Error() string
Error returns the string message, fulfilling the interface required by `error`
func (ee *ExitError) ExitCode() int
ExitCode returns the exit code, fulfilling the interface required by `ExitCoder`
type Flag interface {
fmt.Stringer
// Apply Flag settings to the given flag set
Apply(*flag.FlagSet)
GetName() string
}
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 FlagStringFunc func(Flag) string
FlagStringFunc is used by the help generation to display a flag, which is expected to be a single line.
var FlagStringer FlagStringFunc = stringifyFlag
FlagStringer converts a flag definition to a string. This is used by help to display a flag.
type Float64Flag struct {
Name string
Usage string
EnvVar string
Hidden bool
Value float64
Destination *float64
}
Float64Flag is a flag with type float64
func (f Float64Flag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment
func (f Float64Flag) GetName() string
GetName returns the name of the flag
func (f Float64Flag) String() string
String returns a readable representation of this value (for usage defaults)
type Generic interface {
Set(value string) error
String() string
}
Generic is a generic parseable type identified by a specific flag
type GenericFlag struct {
Name string
Usage string
EnvVar string
Hidden bool
Value Generic
}
GenericFlag is a flag with type Generic
func (f GenericFlag) Apply(set *flag.FlagSet)
Apply takes the flagset and calls Set on the generic flag with the value provided by the user for parsing by the flag
func (f GenericFlag) GetName() string
GetName returns the name of the flag
func (f GenericFlag) String() string
String returns a readable representation of this value (for usage defaults)
type Int64Flag struct {
Name string
Usage string
EnvVar string
Hidden bool
Value int64
Destination *int64
}
Int64Flag is a flag with type int64
func (f Int64Flag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment
func (f Int64Flag) GetName() string
GetName returns the name of the flag
func (f Int64Flag) String() string
String returns a readable representation of this value (for usage defaults)
type Int64Slice []int64
Int64Slice is an opaque type for []int to satisfy flag.Value
func (f *Int64Slice) Set(value string) error
Set parses the value into an integer and appends it to the list of values
func (f *Int64Slice) String() string
String returns a readable representation of this value (for usage defaults)
func (f *Int64Slice) Value() []int64
Value returns the slice of ints set by this flag
type Int64SliceFlag struct {
Name string
Usage string
EnvVar string
Hidden bool
Value *Int64Slice
}
Int64SliceFlag is a flag with type *Int64Slice
func (f Int64SliceFlag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment
func (f Int64SliceFlag) GetName() string
GetName returns the name of the flag
func (f Int64SliceFlag) String() string
String returns a readable representation of this value (for usage defaults)
type IntFlag struct {
Name string
Usage string
EnvVar string
Hidden bool
Value int
Destination *int
}
IntFlag is a flag with type int
func (f IntFlag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment
func (f IntFlag) GetName() string
GetName returns the name of the flag
func (f IntFlag) String() string
String returns a readable representation of this value (for usage defaults)
type IntSlice []int
IntSlice is an opaque type for []int to satisfy flag.Value
func (f *IntSlice) Set(value string) error
Set parses the value into an integer and appends it to the list of values
func (f *IntSlice) String() string
String returns a readable representation of this value (for usage defaults)
func (f *IntSlice) Value() []int
Value returns the slice of ints set by this flag
type IntSliceFlag struct {
Name string
Usage string
EnvVar string
Hidden bool
Value *IntSlice
}
IntSliceFlag is a flag with type *IntSlice
func (f IntSliceFlag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment
func (f IntSliceFlag) GetName() string
GetName returns the name of the flag
func (f IntSliceFlag) String() string
String returns a readable representation of this value (for usage defaults)
type MultiError struct {
Errors []error
}
MultiError is an error that wraps multiple errors.
func NewMultiError(err ...error) MultiError
NewMultiError creates a new MultiError. Pass in one or more errors.
func (m MultiError) Error() string
Error implents the error interface.
type OnUsageErrorFunc func(context *Context, err error, isSubcommand bool) error
OnUsageErrorFunc is executed if an usage error occurs. This is useful for displaying customized usage error messages. This function is able to replace the original error messages. If this function is not set, the "Incorrect usage" is displayed and the execution is interrupted.
type StringFlag struct {
Name string
Usage string
EnvVar string
Hidden bool
Value string
Destination *string
}
StringFlag is a flag with type string
func (f StringFlag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment
func (f StringFlag) GetName() string
GetName returns the name of the flag
func (f StringFlag) String() string
String returns a readable representation of this value (for usage defaults)
type StringSlice []string
StringSlice is an opaque type for []string to satisfy flag.Value
func (f *StringSlice) Set(value string) error
Set appends the string value to the list of values
func (f *StringSlice) String() string
String returns a readable representation of this value (for usage defaults)
func (f *StringSlice) Value() []string
Value returns the slice of strings set by this flag
type StringSliceFlag struct {
Name string
Usage string
EnvVar string
Hidden bool
Value *StringSlice
}
StringSliceFlag is a flag with type *StringSlice
func (f StringSliceFlag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment
func (f StringSliceFlag) GetName() string
GetName returns the name of the flag
func (f StringSliceFlag) String() string
String returns a readable representation of this value (for usage defaults)
type Uint64Flag struct {
Name string
Usage string
EnvVar string
Hidden bool
Value uint64
Destination *uint64
}
Uint64Flag is a flag with type uint64
func (f Uint64Flag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment
func (f Uint64Flag) GetName() string
GetName returns the name of the flag
func (f Uint64Flag) String() string
String returns a readable representation of this value (for usage defaults)
type UintFlag struct {
Name string
Usage string
EnvVar string
Hidden bool
Value uint
Destination *uint
}
UintFlag is a flag with type uint
func (f UintFlag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment
func (f UintFlag) GetName() string
GetName returns the name of the flag
func (f UintFlag) String() string
String returns a readable representation of this value (for usage defaults)