package cli // import "github.com/urfave/cli/v2" Package cli provides a minimal framework for creating and organizing command line Go applications. cli is designed to be easy to understand and write, the most simple cli application can be written as follows: func main() { (&cli.App{}).Run(os.Args) } Of course this application does not do much, so let's make this an actual application: func main() { app := &cli.App{ Name: "greet", Usage: "say a greeting", Action: func(c *cli.Context) error { fmt.Println("Greetings") return nil }, } app.Run(os.Args) } VARIABLES var ( SuggestFlag SuggestFlagFunc = suggestFlag SuggestCommand SuggestCommandFunc = suggestCommand SuggestDidYouMeanTemplate string = suggestDidYouMeanTemplate ) var AppHelpTemplate = `NAME: {{$v := offset .Name 6}}{{wrap .Name 3}}{{if .Usage}} - {{wrap .Usage $v}}{{end}} USAGE: {{if .UsageText}}{{wrap .UsageText 3}}{{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 .Description}} DESCRIPTION: {{wrap .Description 3}}{{end}}{{if len .Authors}} AUTHOR{{with $length := len .Authors}}{{if ne 1 $length}}S{{end}}{{end}}: {{range $index, $author := .Authors}}{{if $index}} {{end}}{{$author}}{{end}}{{end}}{{if .VisibleCommands}} COMMANDS:{{range .VisibleCategories}}{{if .Name}} {{.Name}}:{{range .VisibleCommands}} {{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}{{else}}{{range .VisibleCommands}} {{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}{{end}}{{end}}{{end}}{{if .VisibleFlagCategories}} GLOBAL OPTIONS:{{range .VisibleFlagCategories}} {{if .Name}}{{.Name}} {{end}}{{range .Flags}}{{.}} {{end}}{{end}}{{else}}{{if .VisibleFlags}} GLOBAL OPTIONS: {{range $index, $option := .VisibleFlags}}{{if $index}} {{end}}{{wrap $option.String 6}}{{end}}{{end}}{{end}}{{if .Copyright}} COPYRIGHT: {{wrap .Copyright 3}}{{end}} ` AppHelpTemplate is the text template for the Default help topic. cli.go uses text/template to render templates. You can render custom help text by setting this variable. var CommandHelpTemplate = `NAME: {{$v := offset .HelpName 6}}{{wrap .HelpName 3}}{{if .Usage}} - {{wrap .Usage $v}}{{end}} USAGE: {{if .UsageText}}{{wrap .UsageText 3}}{{else}}{{.HelpName}}{{if .VisibleFlags}} [command options]{{end}} {{if .ArgsUsage}}{{.ArgsUsage}}{{else}}[arguments...]{{end}}{{end}}{{if .Category}} CATEGORY: {{.Category}}{{end}}{{if .Description}} DESCRIPTION: {{wrap .Description 3}}{{end}}{{if .VisibleFlagCategories}} OPTIONS:{{range .VisibleFlagCategories}} {{if .Name}}{{.Name}} {{end}}{{range .Flags}}{{.}} {{end}}{{end}}{{else}}{{if .VisibleFlags}} OPTIONS: {{range .VisibleFlags}}{{.}} {{end}}{{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 FishCompletionTemplate = `# {{ .App.Name }} fish shell completion function __fish_{{ .App.Name }}_no_subcommand --description 'Test if there has been any subcommand yet' for i in (commandline -opc) if contains -- $i{{ range $v := .AllCommands }} {{ $v }}{{ end }} return 1 end end return 0 end {{ range $v := .Completions }}{{ $v }} {{ end }}` var MarkdownDocTemplate = `{{if gt .SectionNum 0}}% {{ .App.Name }} {{ .SectionNum }} {{end}}# NAME {{ .App.Name }}{{ if .App.Usage }} - {{ .App.Usage }}{{ end }} # SYNOPSIS {{ .App.Name }} {{ if .SynopsisArgs }} ` + "```" + ` {{ range $v := .SynopsisArgs }}{{ $v }}{{ end }}` + "```" + ` {{ end }}{{ if .App.Description }} # DESCRIPTION {{ .App.Description }} {{ end }} **Usage**: ` + "```" + `{{ if .App.UsageText }} {{ .App.UsageText }} {{ else }} {{ .App.Name }} [GLOBAL OPTIONS] command [COMMAND OPTIONS] [ARGUMENTS...] {{ end }}` + "```" + ` {{ if .GlobalArgs }} # GLOBAL OPTIONS {{ range $v := .GlobalArgs }} {{ $v }}{{ end }} {{ end }}{{ if .Commands }} # COMMANDS {{ range $v := .Commands }} {{ $v }}{{ end }}{{ end }}` 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: {{if .UsageText}}{{wrap .UsageText 3}}{{else}}{{.HelpName}} command{{if .VisibleFlags}} [command options]{{end}} {{if .ArgsUsage}}{{.ArgsUsage}}{{else}}[arguments...]{{end}}{{end}}{{if .Description}} DESCRIPTION: {{wrap .Description 3}}{{end}} COMMANDS:{{range .VisibleCategories}}{{if .Name}} {{.Name}}:{{range .VisibleCommands}} {{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}{{else}}{{range .VisibleCommands}} {{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}{{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 VersionPrinter = printVersion VersionPrinter prints the version for the App var HelpPrinter helpPrinter = printHelp HelpPrinter is a function that writes the help output. If not set explicitly, this calls HelpPrinterCustom using only the default template functions. If custom logic for printing help is required, this function can be overridden. If the ExtraInfo field is defined on an App, this function should not be modified, as HelpPrinterCustom will be used directly in order to capture the extra information. var HelpPrinterCustom helpPrinterCustom = printHelpCustom HelpPrinterCustom is a function that writes the help output. It is used as the default implementation of HelpPrinter, and may be called directly if the ExtraInfo field is set on an App. In the default implementation, if the customFuncs argument contains a "wrapAt" key, which is a function which takes no arguments and returns an int, this int value will be used to produce a "wrap" function used by the default template to wrap long lines. FUNCTIONS func DefaultAppComplete(cCtx *Context) DefaultAppComplete prints the list of subcommands as the default app completion method func DefaultCompleteWithFlags(cmd *Command) func(cCtx *Context) func FlagNames(name string, aliases []string) []string func HandleAction(action interface{}, cCtx *Context) (err error) HandleAction attempts to figure out which Action signature was used. If it's an ActionFunc or a func with the legacy signature for Action, the func is run! func HandleExitCoder(err error) HandleExitCoder handles errors implementing ExitCoder by printing their message and calling OsExiter with the given exit code. If the given error instead implements MultiError, each error will be checked for the ExitCoder interface, and OsExiter will be called with the last exit code found, or exit code 1 if no ExitCoder is found. This function is the default error-handling behavior for an App. func ShowAppHelp(cCtx *Context) error ShowAppHelp is an action that displays the help. func ShowAppHelpAndExit(c *Context, exitCode int) ShowAppHelpAndExit - Prints the list of subcommands for the app and exits with exit code. 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 ShowCommandHelpAndExit(c *Context, command string, code int) ShowCommandHelpAndExit - exits with code after showing help func ShowCompletions(cCtx *Context) ShowCompletions prints the lists of commands within a given context func ShowSubcommandHelp(cCtx *Context) error ShowSubcommandHelp prints help for the given subcommand func ShowSubcommandHelpAndExit(c *Context, exitCode int) ShowSubcommandHelpAndExit - Prints help for the given subcommand and exits with exit code. func ShowVersion(cCtx *Context) ShowVersion prints the version number of the App TYPES 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 // Description of the program Description string // DefaultCommand is the (optional) name of a command // to run if no command names are passed as CLI arguments. DefaultCommand 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 and help flag HideHelp bool // Boolean to hide built-in help command but keep help flag. // Ignored if HideHelp is true. HideHelpCommand bool // Boolean to hide built-in version flag and the VERSION section of help HideVersion bool // An action to execute when the shell 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 Action ActionFunc // Execute this function if the proper command cannot be found CommandNotFound CommandNotFoundFunc // Execute this function if a 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 // Reader reader to write input to (useful for tests) Reader io.Reader // Writer writer to write output to Writer io.Writer // ErrWriter writes error output ErrWriter io.Writer // ExitErrHandler processes any error encountered while running an App before // it is returned to the caller. If no function is provided, HandleExitCoder // is used as the default behavior. ExitErrHandler ExitErrHandlerFunc // Other custom info Metadata map[string]interface{} // Carries a function which returns app specific info. ExtraInfo func() map[string]string // CustomAppHelpTemplate the text template for app help topic. // cli.go uses text/template to render templates. You can // render custom help text by setting this variable. CustomAppHelpTemplate string // Boolean to enable short-option handling so user can combine several // single-character bool arguments into one // i.e. foobar -o -v -> foobar -ov UseShortOptionHandling bool // Enable suggestions for commands and flags Suggest bool // Has 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) 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 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 error 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) RunContext(ctx context.Context, arguments []string) (err error) RunContext is like Run except it takes a Context that will be passed to its commands and sub-commands. Through this, you can propagate timeouts and cancellation requests 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) ToFishCompletion() (string, error) ToFishCompletion creates a fish completion string for the `*App` The function errors if either parsing or writing of the string fails. func (a *App) ToMan() (string, error) ToMan creates a man page string for the `*App` The function errors if either parsing or writing of the string fails. func (a *App) ToManWithSection(sectionNumber int) (string, error) ToMan creates a man page string with section number for the `*App` The function errors if either parsing or writing of the string fails. func (a *App) ToMarkdown() (string, error) ToMarkdown creates a markdown string for the `*App` The function errors if either parsing or writing of the string fails. 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) VisibleFlagCategories() []VisibleFlagCategory VisibleFlagCategories returns a slice containing all the categories with the flags they contain func (a *App) VisibleFlags() []Flag VisibleFlags returns a slice of the Flags with Hidden=false type Args interface { // Get returns the nth argument, or else a blank string Get(n int) string // First returns the first argument, or else a blank string First() string // Tail returns the rest of the arguments (not the first one) // or else an empty string slice Tail() []string // Len returns the length of the wrapped slice Len() int // Present checks if there are any arguments present Present() bool // Slice returns a copy of the internal slice Slice() []string } 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 shell 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 Category string DefaultText string FilePath string Usage string Required bool Hidden bool HasBeenSet bool Value bool Destination *bool Aliases []string EnvVars []string } BoolFlag is a flag with type bool func (f *BoolFlag) Apply(set *flag.FlagSet) error Apply populates the flag given the flag set and environment func (f *BoolFlag) Get(ctx *Context) bool Get returns the flag’s value in the given Context. func (f *BoolFlag) GetCategory() string GetCategory returns the category for the flag func (f *BoolFlag) GetDefaultText() string GetDefaultText returns the default text for this flag func (f *BoolFlag) GetEnvVars() []string GetEnvVars returns the env vars for this flag func (f *BoolFlag) GetUsage() string GetUsage returns the usage string for the flag func (f *BoolFlag) GetValue() string GetValue returns the flags value as string representation and an empty string if the flag takes no value at all. func (f *BoolFlag) IsRequired() bool IsRequired returns whether or not the flag is required func (f *BoolFlag) IsSet() bool IsSet returns whether or not the flag has been set through env or file func (f *BoolFlag) IsVisible() bool IsVisible returns true if the flag is not hidden, otherwise false func (f *BoolFlag) Names() []string Names returns the names of the flag func (f *BoolFlag) String() string String returns a readable representation of this value (for usage defaults) func (f *BoolFlag) TakesValue() bool TakesValue returns true of the flag takes a value, otherwise false type CategorizableFlag interface { VisibleFlag GetCategory() string } CategorizableFlag is an interface that allows us to potentially use a flag in a categorized representation. type Command struct { // The name of the command Name 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 ActionFunc // Execute this function if a usage error occurs. OnUsageError OnUsageErrorFunc // List of child commands Subcommands []*Command // List of flags to parse Flags []Flag // Treat all flags as normal arguments if true SkipFlagParsing bool // Boolean to hide built-in help command and help flag HideHelp bool // Boolean to hide built-in help command but keep help flag // Ignored if HideHelp is true. HideHelpCommand bool // Boolean to hide this command from help or completion Hidden bool // Boolean to enable short-option handling so user can combine several // single-character bool arguments into one // i.e. foobar -o -v -> foobar -ov UseShortOptionHandling bool // Full name of command for help, defaults to full command name, including parent commands. HelpName string // CustomHelpTemplate 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. CustomHelpTemplate string // Has 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 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) VisibleFlagCategories() []VisibleFlagCategory VisibleFlagCategories returns a slice containing all the visible flag categories with the flags they contain func (c *Command) VisibleFlags() []Flag VisibleFlags returns a slice of the Flags with Hidden=false type CommandCategories interface { // AddCommand adds a command to a category, creating a new category if necessary. AddCommand(category string, command *Command) // Categories returns a slice of categories sorted by name Categories() []CommandCategory } CommandCategories interface allows for category manipulation type CommandCategory interface { // Name returns the category name string Name() string // VisibleCommands returns a slice of the Commands with Hidden=false VisibleCommands() []*Command } CommandCategory is a category containing commands. type CommandNotFoundFunc func(*Context, string) CommandNotFoundFunc is executed if the proper command cannot be found type Commands []*Command type CommandsByName []*Command func (c CommandsByName) Len() int func (c CommandsByName) Less(i, j int) bool func (c CommandsByName) Swap(i, j int) type Context struct { context.Context App *App Command *Command // Has 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 (cCtx *Context) Args() Args Args returns the command line arguments associated with the context. func (cCtx *Context) Bool(name string) bool Bool looks up the value of a local BoolFlag, returns false if not found func (cCtx *Context) Duration(name string) time.Duration Duration looks up the value of a local DurationFlag, returns 0 if not found func (cCtx *Context) FlagNames() []string FlagNames returns a slice of flag names used by the this context and all of its parent contexts. func (cCtx *Context) Float64(name string) float64 Float64 looks up the value of a local Float64Flag, returns 0 if not found func (cCtx *Context) Float64Slice(name string) []float64 Float64Slice looks up the value of a local Float64SliceFlag, returns nil if not found func (cCtx *Context) Generic(name string) interface{} Generic looks up the value of a local GenericFlag, returns nil if not found func (cCtx *Context) Int(name string) int Int looks up the value of a local IntFlag, returns 0 if not found func (cCtx *Context) Int64(name string) int64 Int64 looks up the value of a local Int64Flag, returns 0 if not found func (cCtx *Context) Int64Slice(name string) []int64 Int64Slice looks up the value of a local Int64SliceFlag, returns nil if not found func (cCtx *Context) IntSlice(name string) []int IntSlice looks up the value of a local IntSliceFlag, returns nil if not found func (cCtx *Context) IsSet(name string) bool IsSet determines if the flag was actually set func (cCtx *Context) Lineage() []*Context Lineage returns *this* context and all of its ancestor contexts in order from child to parent func (cCtx *Context) LocalFlagNames() []string LocalFlagNames returns a slice of flag names used in this context. func (cCtx *Context) NArg() int NArg returns the number of the command line arguments. func (cCtx *Context) NumFlags() int NumFlags returns the number of flags set func (cCtx *Context) Path(name string) string Path looks up the value of a local PathFlag, returns "" if not found func (cCtx *Context) Set(name, value string) error Set sets a context flag to a value. func (cCtx *Context) String(name string) string String looks up the value of a local StringFlag, returns "" if not found func (cCtx *Context) StringSlice(name string) []string StringSlice looks up the value of a local StringSliceFlag, returns nil if not found func (cCtx *Context) Timestamp(name string) *time.Time Timestamp gets the timestamp from a flag name func (cCtx *Context) Uint(name string) uint Uint looks up the value of a local UintFlag, returns 0 if not found func (cCtx *Context) Uint64(name string) uint64 Uint64 looks up the value of a local Uint64Flag, returns 0 if not found func (cCtx *Context) Value(name string) interface{} Value returns the value of the flag corresponding to `name` 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 } DocGenerationFlag is an interface that allows documentation generation for the flag type DurationFlag struct { Name string Category string DefaultText string FilePath string Usage string Required bool Hidden bool HasBeenSet bool Value time.Duration Destination *time.Duration Aliases []string EnvVars []string } DurationFlag is a flag with type time.Duration func (f *DurationFlag) Apply(set *flag.FlagSet) error Apply populates the flag given the flag set and environment func (f *DurationFlag) Get(ctx *Context) time.Duration Get returns the flag’s value in the given Context. func (f *DurationFlag) GetCategory() string GetCategory returns the category for the flag func (f *DurationFlag) GetDefaultText() string GetDefaultText returns the default text for this flag func (f *DurationFlag) GetEnvVars() []string GetEnvVars returns the env vars for this flag func (f *DurationFlag) GetUsage() string GetUsage returns the usage string for the flag func (f *DurationFlag) GetValue() string GetValue returns the flags value as string representation and an empty string if the flag takes no value at all. func (f *DurationFlag) IsRequired() bool IsRequired returns whether or not the flag is required func (f *DurationFlag) IsSet() bool IsSet returns whether or not the flag has been set through env or file func (f *DurationFlag) IsVisible() bool IsVisible returns true if the flag is not hidden, otherwise false func (f *DurationFlag) Names() []string Names returns the names of the flag func (f *DurationFlag) String() string String returns a readable representation of this value (for usage defaults) func (f *DurationFlag) TakesValue() bool TakesValue returns true of the flag takes a value, otherwise false type ErrorFormatter interface { Format(s fmt.State, verb rune) } ErrorFormatter is the interface that will suitably format the error output type ExitCoder interface { error ExitCode() int } ExitCoder is the interface checked by `App` and `Command` for a custom exit code func Exit(message interface{}, exitCode int) ExitCoder Exit wraps a message and exit code into an error, which by default is handled with a call to os.Exit during default error handling. This is the simplest way to trigger a non-zero exit code for an App without having to call os.Exit manually. During testing, this behavior can be avoided by overiding the ExitErrHandler function on an App or the package-global OsExiter function. func NewExitError(message interface{}, exitCode int) ExitCoder NewExitError calls Exit to create a new ExitCoder. Deprecated: This function is a duplicate of Exit and will eventually be removed. type ExitErrHandlerFunc func(cCtx *Context, err error) ExitErrHandlerFunc is executed if provided in order to handle exitError values returned by Actions and Before/After functions. type Flag interface { fmt.Stringer // Apply Flag settings to the given flag set Apply(*flag.FlagSet) error Names() []string IsSet() bool } 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. var BashCompletionFlag Flag = &BoolFlag{ Name: "generate-bash-completion", Hidden: true, } BashCompletionFlag enables bash-completion for all commands and subcommands var HelpFlag Flag = &BoolFlag{ Name: "help", Aliases: []string{"h"}, Usage: "show help", } 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 VersionFlag Flag = &BoolFlag{ Name: "version", Aliases: []string{"v"}, Usage: "print the version", } VersionFlag prints the version for the application type FlagCategories interface { // AddFlags adds a flag to a category, creating a new category if necessary. AddFlag(category string, fl Flag) // VisibleCategories returns a slice of visible flag categories sorted by name VisibleCategories() []VisibleFlagCategory } FlagCategories interface allows for category manipulation type FlagEnvHintFunc func(envVars []string, str string) string FlagEnvHintFunc is used by the default FlagStringFunc to annotate flag help with the environment variable details. var FlagEnvHinter FlagEnvHintFunc = withEnvHint FlagEnvHinter annotates flag help message with the environment variable details. This is used by the default FlagStringer. type FlagFileHintFunc func(filePath, str string) string FlagFileHintFunc is used by the default FlagStringFunc to annotate flag help with the file path details. var FlagFileHinter FlagFileHintFunc = withFileHint FlagFileHinter annotates flag help message with the environment variable details. This is used by the default FlagStringer. type FlagNamePrefixFunc func(fullName []string, placeholder string) string FlagNamePrefixFunc is used by the default FlagStringFunc to create prefix text for a flag's full name. var FlagNamePrefixer FlagNamePrefixFunc = prefixedNames FlagNamePrefixer converts a full flag name and its placeholder into the help message flag prefix. This is used by the default FlagStringer. 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 FlagsByName []Flag FlagsByName is a slice of Flag. func (f FlagsByName) Len() int func (f FlagsByName) Less(i, j int) bool func (f FlagsByName) Swap(i, j int) type Float64Flag struct { Name string Category string DefaultText string FilePath string Usage string Required bool Hidden bool HasBeenSet bool Value float64 Destination *float64 Aliases []string EnvVars []string } Float64Flag is a flag with type float64 func (f *Float64Flag) Apply(set *flag.FlagSet) error Apply populates the flag given the flag set and environment func (f *Float64Flag) Get(ctx *Context) float64 Get returns the flag’s value in the given Context. func (f *Float64Flag) GetCategory() string GetCategory returns the category for the flag func (f *Float64Flag) GetDefaultText() string GetDefaultText returns the default text for this flag func (f *Float64Flag) GetEnvVars() []string GetEnvVars returns the env vars for this flag func (f *Float64Flag) GetUsage() string GetUsage returns the usage string for the flag func (f *Float64Flag) GetValue() string GetValue returns the flags value as string representation and an empty string if the flag takes no value at all. func (f *Float64Flag) IsRequired() bool IsRequired returns whether or not the flag is required func (f *Float64Flag) IsSet() bool IsSet returns whether or not the flag has been set through env or file func (f *Float64Flag) IsVisible() bool IsVisible returns true if the flag is not hidden, otherwise false func (f *Float64Flag) Names() []string Names returns the names of the flag func (f *Float64Flag) String() string String returns a readable representation of this value (for usage defaults) func (f *Float64Flag) TakesValue() bool TakesValue returns true of the flag takes a value, otherwise false type Float64Slice struct { // Has unexported fields. } Float64Slice wraps []float64 to satisfy flag.Value func NewFloat64Slice(defaults ...float64) *Float64Slice NewFloat64Slice makes a *Float64Slice with default values func (f *Float64Slice) Get() interface{} Get returns the slice of float64s set by this flag func (f *Float64Slice) Serialize() string Serialize allows Float64Slice to fulfill Serializer func (f *Float64Slice) Set(value string) error Set parses the value into a float64 and appends it to the list of values func (f *Float64Slice) String() string String returns a readable representation of this value (for usage defaults) func (f *Float64Slice) Value() []float64 Value returns the slice of float64s set by this flag type Float64SliceFlag struct { Name string Category string DefaultText string FilePath string Usage string Required bool Hidden bool HasBeenSet bool Value *Float64Slice Destination *Float64Slice Aliases []string EnvVars []string } Float64SliceFlag is a flag with type *Float64Slice func (f *Float64SliceFlag) Apply(set *flag.FlagSet) error Apply populates the flag given the flag set and environment func (f *Float64SliceFlag) Get(ctx *Context) []float64 Get returns the flag’s value in the given Context. func (f *Float64SliceFlag) GetCategory() string GetCategory returns the category for the flag func (f *Float64SliceFlag) GetDefaultText() string GetDefaultText returns the default text for this flag func (f *Float64SliceFlag) GetDestination() []float64 func (f *Float64SliceFlag) GetEnvVars() []string GetEnvVars returns the env vars for this flag func (f *Float64SliceFlag) GetUsage() string GetUsage returns the usage string for the flag func (f *Float64SliceFlag) GetValue() string GetValue returns the flags value as string representation and an empty string if the flag takes no value at all. func (f *Float64SliceFlag) IsRequired() bool IsRequired returns whether or not the flag is required func (f *Float64SliceFlag) IsSet() bool IsSet returns whether or not the flag has been set through env or file func (f *Float64SliceFlag) IsVisible() bool IsVisible returns true if the flag is not hidden, otherwise false func (f *Float64SliceFlag) Names() []string Names returns the names of the flag func (f *Float64SliceFlag) SetDestination(slice []float64) func (f *Float64SliceFlag) SetValue(slice []float64) func (f *Float64SliceFlag) String() string String returns a readable representation of this value (for usage defaults) func (f *Float64SliceFlag) TakesValue() bool TakesValue returns true if the flag takes a value, otherwise false 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 Category string DefaultText string FilePath string Usage string Required bool Hidden bool HasBeenSet bool Value Generic Destination *Generic Aliases []string EnvVars []string TakesFile bool } GenericFlag is a flag with type Generic func (f GenericFlag) Apply(set *flag.FlagSet) error 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) Get(ctx *Context) interface{} Get returns the flag’s value in the given Context. func (f *GenericFlag) GetCategory() string GetCategory returns the category for the flag func (f *GenericFlag) GetDefaultText() string GetDefaultText returns the default text for this flag func (f *GenericFlag) GetEnvVars() []string GetEnvVars returns the env vars for this flag func (f *GenericFlag) GetUsage() string GetUsage returns the usage string for the flag func (f *GenericFlag) GetValue() string GetValue returns the flags value as string representation and an empty string if the flag takes no value at all. func (f *GenericFlag) IsRequired() bool IsRequired returns whether or not the flag is required func (f *GenericFlag) IsSet() bool IsSet returns whether or not the flag has been set through env or file func (f *GenericFlag) IsVisible() bool IsVisible returns true if the flag is not hidden, otherwise false func (f *GenericFlag) Names() []string Names returns the names of the flag func (f *GenericFlag) String() string String returns a readable representation of this value (for usage defaults) func (f *GenericFlag) TakesValue() bool TakesValue returns true of the flag takes a value, otherwise false type Int64Flag struct { Name string Category string DefaultText string FilePath string Usage string Required bool Hidden bool HasBeenSet bool Value int64 Destination *int64 Aliases []string EnvVars []string Base int } Int64Flag is a flag with type int64 func (f *Int64Flag) Apply(set *flag.FlagSet) error Apply populates the flag given the flag set and environment func (f *Int64Flag) Get(ctx *Context) int64 Get returns the flag’s value in the given Context. func (f *Int64Flag) GetCategory() string GetCategory returns the category for the flag func (f *Int64Flag) GetDefaultText() string GetDefaultText returns the default text for this flag func (f *Int64Flag) GetEnvVars() []string GetEnvVars returns the env vars for this flag func (f *Int64Flag) GetUsage() string GetUsage returns the usage string for the flag func (f *Int64Flag) GetValue() string GetValue returns the flags value as string representation and an empty string if the flag takes no value at all. func (f *Int64Flag) IsRequired() bool IsRequired returns whether or not the flag is required func (f *Int64Flag) IsSet() bool IsSet returns whether or not the flag has been set through env or file func (f *Int64Flag) IsVisible() bool IsVisible returns true if the flag is not hidden, otherwise false func (f *Int64Flag) Names() []string Names returns the names of the flag func (f *Int64Flag) String() string String returns a readable representation of this value (for usage defaults) func (f *Int64Flag) TakesValue() bool TakesValue returns true of the flag takes a value, otherwise false type Int64Slice struct { // Has unexported fields. } Int64Slice wraps []int64 to satisfy flag.Value func NewInt64Slice(defaults ...int64) *Int64Slice NewInt64Slice makes an *Int64Slice with default values func (i *Int64Slice) Get() interface{} Get returns the slice of ints set by this flag func (i *Int64Slice) Serialize() string Serialize allows Int64Slice to fulfill Serializer func (i *Int64Slice) Set(value string) error Set parses the value into an integer and appends it to the list of values func (i *Int64Slice) String() string String returns a readable representation of this value (for usage defaults) func (i *Int64Slice) Value() []int64 Value returns the slice of ints set by this flag type Int64SliceFlag struct { Name string Category string DefaultText string FilePath string Usage string Required bool Hidden bool HasBeenSet bool Value *Int64Slice Destination *Int64Slice Aliases []string EnvVars []string } Int64SliceFlag is a flag with type *Int64Slice func (f *Int64SliceFlag) Apply(set *flag.FlagSet) error Apply populates the flag given the flag set and environment func (f *Int64SliceFlag) Get(ctx *Context) []int64 Get returns the flag’s value in the given Context. func (f *Int64SliceFlag) GetCategory() string GetCategory returns the category for the flag func (f *Int64SliceFlag) GetDefaultText() string GetDefaultText returns the default text for this flag func (f *Int64SliceFlag) GetDestination() []int64 func (f *Int64SliceFlag) GetEnvVars() []string GetEnvVars returns the env vars for this flag func (f *Int64SliceFlag) GetUsage() string GetUsage returns the usage string for the flag func (f *Int64SliceFlag) GetValue() string GetValue returns the flags value as string representation and an empty string if the flag takes no value at all. func (f *Int64SliceFlag) IsRequired() bool IsRequired returns whether or not the flag is required func (f *Int64SliceFlag) IsSet() bool IsSet returns whether or not the flag has been set through env or file func (f *Int64SliceFlag) IsVisible() bool IsVisible returns true if the flag is not hidden, otherwise false func (f *Int64SliceFlag) Names() []string Names returns the names of the flag func (f *Int64SliceFlag) SetDestination(slice []int64) func (f *Int64SliceFlag) SetValue(slice []int64) func (f *Int64SliceFlag) String() string String returns a readable representation of this value (for usage defaults) func (f *Int64SliceFlag) TakesValue() bool TakesValue returns true of the flag takes a value, otherwise false type IntFlag struct { Name string Category string DefaultText string FilePath string Usage string Required bool Hidden bool HasBeenSet bool Value int Destination *int Aliases []string EnvVars []string Base int } IntFlag is a flag with type int func (f *IntFlag) Apply(set *flag.FlagSet) error Apply populates the flag given the flag set and environment func (f *IntFlag) Get(ctx *Context) int Get returns the flag’s value in the given Context. func (f *IntFlag) GetCategory() string GetCategory returns the category for the flag func (f *IntFlag) GetDefaultText() string GetDefaultText returns the default text for this flag func (f *IntFlag) GetEnvVars() []string GetEnvVars returns the env vars for this flag func (f *IntFlag) GetUsage() string GetUsage returns the usage string for the flag func (f *IntFlag) GetValue() string GetValue returns the flags value as string representation and an empty string if the flag takes no value at all. func (f *IntFlag) IsRequired() bool IsRequired returns whether or not the flag is required func (f *IntFlag) IsSet() bool IsSet returns whether or not the flag has been set through env or file func (f *IntFlag) IsVisible() bool IsVisible returns true if the flag is not hidden, otherwise false func (f *IntFlag) Names() []string Names returns the names of the flag func (f *IntFlag) String() string String returns a readable representation of this value (for usage defaults) func (f *IntFlag) TakesValue() bool TakesValue returns true of the flag takes a value, otherwise false type IntSlice struct { // Has unexported fields. } IntSlice wraps []int to satisfy flag.Value func NewIntSlice(defaults ...int) *IntSlice NewIntSlice makes an *IntSlice with default values func (i *IntSlice) Get() interface{} Get returns the slice of ints set by this flag func (i *IntSlice) Serialize() string Serialize allows IntSlice to fulfill Serializer func (i *IntSlice) Set(value string) error Set parses the value into an integer and appends it to the list of values func (i *IntSlice) SetInt(value int) TODO: Consistently have specific Set function for Int64 and Float64 ? SetInt directly adds an integer to the list of values func (i *IntSlice) String() string String returns a readable representation of this value (for usage defaults) func (i *IntSlice) Value() []int Value returns the slice of ints set by this flag type IntSliceFlag struct { Name string Category string DefaultText string FilePath string Usage string Required bool Hidden bool HasBeenSet bool Value *IntSlice Destination *IntSlice Aliases []string EnvVars []string } IntSliceFlag is a flag with type *IntSlice func (f *IntSliceFlag) Apply(set *flag.FlagSet) error Apply populates the flag given the flag set and environment func (f *IntSliceFlag) Get(ctx *Context) []int Get returns the flag’s value in the given Context. func (f *IntSliceFlag) GetCategory() string GetCategory returns the category for the flag func (f *IntSliceFlag) GetDefaultText() string GetDefaultText returns the default text for this flag func (f *IntSliceFlag) GetDestination() []int func (f *IntSliceFlag) GetEnvVars() []string GetEnvVars returns the env vars for this flag func (f *IntSliceFlag) GetUsage() string GetUsage returns the usage string for the flag func (f *IntSliceFlag) GetValue() string GetValue returns the flags value as string representation and an empty string if the flag takes no value at all. func (f *IntSliceFlag) IsRequired() bool IsRequired returns whether or not the flag is required func (f *IntSliceFlag) IsSet() bool IsSet returns whether or not the flag has been set through env or file func (f *IntSliceFlag) IsVisible() bool IsVisible returns true if the flag is not hidden, otherwise false func (f *IntSliceFlag) Names() []string Names returns the names of the flag func (f *IntSliceFlag) SetDestination(slice []int) func (f *IntSliceFlag) SetValue(slice []int) func (f *IntSliceFlag) String() string String returns a readable representation of this value (for usage defaults) func (f *IntSliceFlag) TakesValue() bool TakesValue returns true of the flag takes a value, otherwise false type MultiError interface { error Errors() []error } MultiError is an error that wraps multiple errors. type MultiFloat64Flag = SliceFlag[*Float64SliceFlag, []float64, float64] MultiFloat64Flag extends Float64SliceFlag with support for using slices directly, as Value and/or Destination. See also SliceFlag. type MultiInt64Flag = SliceFlag[*Int64SliceFlag, []int64, int64] MultiInt64Flag extends Int64SliceFlag with support for using slices directly, as Value and/or Destination. See also SliceFlag. type MultiIntFlag = SliceFlag[*IntSliceFlag, []int, int] MultiIntFlag extends IntSliceFlag with support for using slices directly, as Value and/or Destination. See also SliceFlag. type MultiStringFlag = SliceFlag[*StringSliceFlag, []string, string] MultiStringFlag extends StringSliceFlag with support for using slices directly, as Value and/or Destination. See also SliceFlag. type OnUsageErrorFunc func(cCtx *Context, err error, isSubcommand bool) error OnUsageErrorFunc is executed if a 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 Path = string type PathFlag struct { Name string Category string DefaultText string FilePath string Usage string Required bool Hidden bool HasBeenSet bool Value Path Destination *Path Aliases []string EnvVars []string TakesFile bool } PathFlag is a flag with type Path func (f *PathFlag) Apply(set *flag.FlagSet) error Apply populates the flag given the flag set and environment func (f *PathFlag) Get(ctx *Context) string Get returns the flag’s value in the given Context. func (f *PathFlag) GetCategory() string GetCategory returns the category for the flag func (f *PathFlag) GetDefaultText() string GetDefaultText returns the default text for this flag func (f *PathFlag) GetEnvVars() []string GetEnvVars returns the env vars for this flag func (f *PathFlag) GetUsage() string GetUsage returns the usage string for the flag func (f *PathFlag) GetValue() string GetValue returns the flags value as string representation and an empty string if the flag takes no value at all. func (f *PathFlag) IsRequired() bool IsRequired returns whether or not the flag is required func (f *PathFlag) IsSet() bool IsSet returns whether or not the flag has been set through env or file func (f *PathFlag) IsVisible() bool IsVisible returns true if the flag is not hidden, otherwise false func (f *PathFlag) Names() []string Names returns the names of the flag func (f *PathFlag) String() string String returns a readable representation of this value (for usage defaults) func (f *PathFlag) TakesValue() bool TakesValue returns true of the flag takes a value, otherwise false type RequiredFlag interface { Flag IsRequired() 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 Serializer interface { Serialize() string } Serializer is used to circumvent the limitations of flag.FlagSet.Set type SliceFlag[T SliceFlagTarget[E], S ~[]E, E any] struct { Target T Value S Destination *S } SliceFlag extends implementations like StringSliceFlag and IntSliceFlag with support for using slices directly, as Value and/or Destination. See also SliceFlagTarget, MultiStringFlag, MultiFloat64Flag, MultiInt64Flag, MultiIntFlag. func (x *SliceFlag[T, S, E]) Apply(set *flag.FlagSet) error func (x *SliceFlag[T, S, E]) GetCategory() string func (x *SliceFlag[T, S, E]) GetDefaultText() string func (x *SliceFlag[T, S, E]) GetDestination() S func (x *SliceFlag[T, S, E]) GetEnvVars() []string func (x *SliceFlag[T, S, E]) GetUsage() string func (x *SliceFlag[T, S, E]) GetValue() string func (x *SliceFlag[T, S, E]) IsRequired() bool func (x *SliceFlag[T, S, E]) IsSet() bool func (x *SliceFlag[T, S, E]) IsVisible() bool func (x *SliceFlag[T, S, E]) Names() []string func (x *SliceFlag[T, S, E]) SetDestination(slice S) func (x *SliceFlag[T, S, E]) SetValue(slice S) func (x *SliceFlag[T, S, E]) String() string func (x *SliceFlag[T, S, E]) TakesValue() bool type SliceFlagTarget[E any] interface { Flag RequiredFlag DocGenerationFlag VisibleFlag CategorizableFlag // SetValue should propagate the given slice to the target, ideally as a new value. // Note that a nil slice should nil/clear any existing value (modelled as ~[]E). SetValue(slice []E) // SetDestination should propagate the given slice to the target, ideally as a new value. // Note that a nil slice should nil/clear any existing value (modelled as ~*[]E). SetDestination(slice []E) // GetDestination should return the current value referenced by any destination, or nil if nil/unset. GetDestination() []E } SliceFlagTarget models a target implementation for use with SliceFlag. The three methods, SetValue, SetDestination, and GetDestination, are necessary to propagate Value and Destination, where Value is propagated inwards (initially), and Destination is propagated outwards (on every update). type StringFlag struct { Name string Category string DefaultText string FilePath string Usage string Required bool Hidden bool HasBeenSet bool Value string Destination *string Aliases []string EnvVars []string TakesFile bool } StringFlag is a flag with type string func (f *StringFlag) Apply(set *flag.FlagSet) error Apply populates the flag given the flag set and environment func (f *StringFlag) Get(ctx *Context) string Get returns the flag’s value in the given Context. func (f *StringFlag) GetCategory() string GetCategory returns the category for the flag func (f *StringFlag) GetDefaultText() string GetDefaultText returns the default text for this flag func (f *StringFlag) GetEnvVars() []string GetEnvVars returns the env vars for this flag func (f *StringFlag) GetUsage() string GetUsage returns the usage string for the flag func (f *StringFlag) GetValue() string GetValue returns the flags value as string representation and an empty string if the flag takes no value at all. func (f *StringFlag) IsRequired() bool IsRequired returns whether or not the flag is required func (f *StringFlag) IsSet() bool IsSet returns whether or not the flag has been set through env or file func (f *StringFlag) IsVisible() bool IsVisible returns true if the flag is not hidden, otherwise false func (f *StringFlag) Names() []string Names returns the names of the flag func (f *StringFlag) String() string String returns a readable representation of this value (for usage defaults) func (f *StringFlag) TakesValue() bool TakesValue returns true of the flag takes a value, otherwise false type StringSlice struct { // Has unexported fields. } StringSlice wraps a []string to satisfy flag.Value func NewStringSlice(defaults ...string) *StringSlice NewStringSlice creates a *StringSlice with default values func (s *StringSlice) Get() interface{} Get returns the slice of strings set by this flag func (s *StringSlice) Serialize() string Serialize allows StringSlice to fulfill Serializer func (s *StringSlice) Set(value string) error Set appends the string value to the list of values func (s *StringSlice) String() string String returns a readable representation of this value (for usage defaults) func (s *StringSlice) Value() []string Value returns the slice of strings set by this flag type StringSliceFlag struct { Name string Category string DefaultText string FilePath string Usage string Required bool Hidden bool HasBeenSet bool Value *StringSlice Destination *StringSlice Aliases []string EnvVars []string TakesFile bool } StringSliceFlag is a flag with type *StringSlice func (f *StringSliceFlag) Apply(set *flag.FlagSet) error Apply populates the flag given the flag set and environment func (f *StringSliceFlag) Get(ctx *Context) []string Get returns the flag’s value in the given Context. func (f *StringSliceFlag) GetCategory() string GetCategory returns the category for the flag func (f *StringSliceFlag) GetDefaultText() string GetDefaultText returns the default text for this flag func (f *StringSliceFlag) GetDestination() []string func (f *StringSliceFlag) GetEnvVars() []string GetEnvVars returns the env vars for this flag func (f *StringSliceFlag) GetUsage() string GetUsage returns the usage string for the flag func (f *StringSliceFlag) GetValue() string GetValue returns the flags value as string representation and an empty string if the flag takes no value at all. func (f *StringSliceFlag) IsRequired() bool IsRequired returns whether or not the flag is required func (f *StringSliceFlag) IsSet() bool IsSet returns whether or not the flag has been set through env or file func (f *StringSliceFlag) IsVisible() bool IsVisible returns true if the flag is not hidden, otherwise false func (f *StringSliceFlag) Names() []string Names returns the names of the flag func (f *StringSliceFlag) SetDestination(slice []string) func (f *StringSliceFlag) SetValue(slice []string) func (f *StringSliceFlag) String() string String returns a readable representation of this value (for usage defaults) func (f *StringSliceFlag) TakesValue() bool TakesValue returns true of the flag takes a value, otherwise false type SuggestCommandFunc func(commands []*Command, provided string) string type SuggestFlagFunc func(flags []Flag, provided string, hideHelp bool) string type Timestamp struct { // Has unexported fields. } Timestamp wrap to satisfy golang's flag interface. func NewTimestamp(timestamp time.Time) *Timestamp Timestamp constructor func (t *Timestamp) Get() interface{} Get returns the flag structure func (t *Timestamp) Set(value string) error Parses the string value to timestamp func (t *Timestamp) SetLayout(layout string) Set the timestamp string layout for future parsing func (t *Timestamp) SetLocation(loc *time.Location) Set perceived timezone of the to-be parsed time string func (t *Timestamp) SetTimestamp(value time.Time) Set the timestamp value directly func (t *Timestamp) String() string String returns a readable representation of this value (for usage defaults) func (t *Timestamp) Value() *time.Time Value returns the timestamp value stored in the flag type TimestampFlag struct { Name string Category string DefaultText string FilePath string Usage string Required bool Hidden bool HasBeenSet bool Value *Timestamp Destination *Timestamp Aliases []string EnvVars []string Layout string Timezone *time.Location } TimestampFlag is a flag with type *Timestamp func (f *TimestampFlag) Apply(set *flag.FlagSet) error Apply populates the flag given the flag set and environment func (f *TimestampFlag) Get(ctx *Context) *time.Time Get returns the flag’s value in the given Context. func (f *TimestampFlag) GetCategory() string GetCategory returns the category for the flag func (f *TimestampFlag) GetDefaultText() string GetDefaultText returns the default text for this flag func (f *TimestampFlag) GetEnvVars() []string GetEnvVars returns the env vars for this flag func (f *TimestampFlag) GetUsage() string GetUsage returns the usage string for the flag func (f *TimestampFlag) GetValue() string GetValue returns the flags value as string representation and an empty string if the flag takes no value at all. func (f *TimestampFlag) IsRequired() bool IsRequired returns whether or not the flag is required func (f *TimestampFlag) IsSet() bool IsSet returns whether or not the flag has been set through env or file func (f *TimestampFlag) IsVisible() bool IsVisible returns true if the flag is not hidden, otherwise false func (f *TimestampFlag) Names() []string Names returns the names of the flag func (f *TimestampFlag) String() string String returns a readable representation of this value (for usage defaults) func (f *TimestampFlag) TakesValue() bool TakesValue returns true of the flag takes a value, otherwise false type Uint64Flag struct { Name string Category string DefaultText string FilePath string Usage string Required bool Hidden bool HasBeenSet bool Value uint64 Destination *uint64 Aliases []string EnvVars []string Base int } Uint64Flag is a flag with type uint64 func (f *Uint64Flag) Apply(set *flag.FlagSet) error Apply populates the flag given the flag set and environment func (f *Uint64Flag) Get(ctx *Context) uint64 Get returns the flag’s value in the given Context. func (f *Uint64Flag) GetCategory() string GetCategory returns the category for the flag func (f *Uint64Flag) GetDefaultText() string GetDefaultText returns the default text for this flag func (f *Uint64Flag) GetEnvVars() []string GetEnvVars returns the env vars for this flag func (f *Uint64Flag) GetUsage() string GetUsage returns the usage string for the flag func (f *Uint64Flag) GetValue() string GetValue returns the flags value as string representation and an empty string if the flag takes no value at all. func (f *Uint64Flag) IsRequired() bool IsRequired returns whether or not the flag is required func (f *Uint64Flag) IsSet() bool IsSet returns whether or not the flag has been set through env or file func (f *Uint64Flag) IsVisible() bool IsVisible returns true if the flag is not hidden, otherwise false func (f *Uint64Flag) Names() []string Names returns the names of the flag func (f *Uint64Flag) String() string String returns a readable representation of this value (for usage defaults) func (f *Uint64Flag) TakesValue() bool TakesValue returns true of the flag takes a value, otherwise false type UintFlag struct { Name string Category string DefaultText string FilePath string Usage string Required bool Hidden bool HasBeenSet bool Value uint Destination *uint Aliases []string EnvVars []string Base int } UintFlag is a flag with type uint func (f *UintFlag) Apply(set *flag.FlagSet) error Apply populates the flag given the flag set and environment func (f *UintFlag) Get(ctx *Context) uint Get returns the flag’s value in the given Context. func (f *UintFlag) GetCategory() string GetCategory returns the category for the flag func (f *UintFlag) GetDefaultText() string GetDefaultText returns the default text for this flag func (f *UintFlag) GetEnvVars() []string GetEnvVars returns the env vars for this flag func (f *UintFlag) GetUsage() string GetUsage returns the usage string for the flag func (f *UintFlag) GetValue() string GetValue returns the flags value as string representation and an empty string if the flag takes no value at all. func (f *UintFlag) IsRequired() bool IsRequired returns whether or not the flag is required func (f *UintFlag) IsSet() bool IsSet returns whether or not the flag has been set through env or file func (f *UintFlag) IsVisible() bool IsVisible returns true if the flag is not hidden, otherwise false func (f *UintFlag) Names() []string Names returns the names of the flag func (f *UintFlag) String() string String returns a readable representation of this value (for usage defaults) func (f *UintFlag) TakesValue() bool TakesValue returns true of the flag takes a value, otherwise false type VisibleFlag interface { Flag // IsVisible returns true if the flag is not hidden, otherwise false IsVisible() bool } VisibleFlag is an interface that allows to check if a flag is visible type VisibleFlagCategory interface { // Name returns the category name string Name() string // Flags returns a slice of VisibleFlag sorted by name Flags() []VisibleFlag } VisibleFlagCategory is a category containing flags. package altsrc // import "github.com/urfave/cli/v2/altsrc" FUNCTIONS func ApplyInputSourceValues(cCtx *cli.Context, inputSourceContext InputSourceContext, flags []cli.Flag) error ApplyInputSourceValues iterates over all provided flags and executes ApplyInputSourceValue on flags implementing the FlagInputSourceExtension interface to initialize these flags to an alternate input source. func InitInputSource(flags []cli.Flag, createInputSource func() (InputSourceContext, error)) cli.BeforeFunc InitInputSource is used to to setup an InputSourceContext on a cli.Command Before method. It will create a new input source based on the func provided. If there is no error it will then apply the new input source to any flags that are supported by the input source func InitInputSourceWithContext(flags []cli.Flag, createInputSource func(cCtx *cli.Context) (InputSourceContext, error)) cli.BeforeFunc InitInputSourceWithContext is used to to setup an InputSourceContext on a cli.Command Before method. It will create a new input source based on the func provided with potentially using existing cli.Context values to initialize itself. If there is no error it will then apply the new input source to any flags that are supported by the input source func NewJSONSourceFromFlagFunc(flag string) func(c *cli.Context) (InputSourceContext, error) NewJSONSourceFromFlagFunc returns a func that takes a cli.Context and returns an InputSourceContext suitable for retrieving config variables from a file containing JSON data with the file name defined by the given flag. func NewTomlSourceFromFlagFunc(flagFileName string) func(cCtx *cli.Context) (InputSourceContext, error) NewTomlSourceFromFlagFunc creates a new TOML InputSourceContext from a provided flag name and source context. func NewYamlSourceFromFlagFunc(flagFileName string) func(cCtx *cli.Context) (InputSourceContext, error) NewYamlSourceFromFlagFunc creates a new Yaml InputSourceContext from a provided flag name and source context. TYPES type BoolFlag struct { *cli.BoolFlag // Has unexported fields. } BoolFlag is the flag type that wraps cli.BoolFlag to allow for other values to be specified func NewBoolFlag(fl *cli.BoolFlag) *BoolFlag NewBoolFlag creates a new BoolFlag func (f *BoolFlag) Apply(set *flag.FlagSet) error Apply saves the flagSet for later usage calls, then calls the wrapped BoolFlag.Apply func (f *BoolFlag) ApplyInputSourceValue(cCtx *cli.Context, isc InputSourceContext) error ApplyInputSourceValue applies a Bool value to the flagSet if required type DurationFlag struct { *cli.DurationFlag // Has unexported fields. } DurationFlag is the flag type that wraps cli.DurationFlag to allow for other values to be specified func NewDurationFlag(fl *cli.DurationFlag) *DurationFlag NewDurationFlag creates a new DurationFlag func (f *DurationFlag) Apply(set *flag.FlagSet) error Apply saves the flagSet for later usage calls, then calls the wrapped DurationFlag.Apply func (f *DurationFlag) ApplyInputSourceValue(cCtx *cli.Context, isc InputSourceContext) error ApplyInputSourceValue applies a Duration value to the flagSet if required type FlagInputSourceExtension interface { cli.Flag ApplyInputSourceValue(cCtx *cli.Context, isc InputSourceContext) error } FlagInputSourceExtension is an extension interface of cli.Flag that allows a value to be set on the existing parsed flags. type Float64Flag struct { *cli.Float64Flag // Has unexported fields. } Float64Flag is the flag type that wraps cli.Float64Flag to allow for other values to be specified func NewFloat64Flag(fl *cli.Float64Flag) *Float64Flag NewFloat64Flag creates a new Float64Flag func (f *Float64Flag) Apply(set *flag.FlagSet) error Apply saves the flagSet for later usage calls, then calls the wrapped Float64Flag.Apply func (f *Float64Flag) ApplyInputSourceValue(cCtx *cli.Context, isc InputSourceContext) error ApplyInputSourceValue applies a Float64 value to the flagSet if required type Float64SliceFlag struct { *cli.Float64SliceFlag // Has unexported fields. } Float64SliceFlag is the flag type that wraps cli.Float64SliceFlag to allow for other values to be specified func NewFloat64SliceFlag(fl *cli.Float64SliceFlag) *Float64SliceFlag NewFloat64SliceFlag creates a new Float64SliceFlag func (f *Float64SliceFlag) Apply(set *flag.FlagSet) error Apply saves the flagSet for later usage calls, then calls the wrapped Float64SliceFlag.Apply type GenericFlag struct { *cli.GenericFlag // Has unexported fields. } GenericFlag is the flag type that wraps cli.GenericFlag to allow for other values to be specified func NewGenericFlag(fl *cli.GenericFlag) *GenericFlag NewGenericFlag creates a new GenericFlag func (f *GenericFlag) Apply(set *flag.FlagSet) error Apply saves the flagSet for later usage calls, then calls the wrapped GenericFlag.Apply func (f *GenericFlag) ApplyInputSourceValue(cCtx *cli.Context, isc InputSourceContext) error ApplyInputSourceValue applies a generic value to the flagSet if required type InputSourceContext interface { Source() string Int(name string) (int, error) Duration(name string) (time.Duration, error) Float64(name string) (float64, error) String(name string) (string, error) StringSlice(name string) ([]string, error) IntSlice(name string) ([]int, error) Generic(name string) (cli.Generic, error) Bool(name string) (bool, error) // Has unexported methods. } InputSourceContext is an interface used to allow other input sources to be implemented as needed. Source returns an identifier for the input source. In case of file source it should return path to the file. func NewJSONSource(data []byte) (InputSourceContext, error) NewJSONSource returns an InputSourceContext suitable for retrieving config variables from raw JSON data. func NewJSONSourceFromFile(f string) (InputSourceContext, error) NewJSONSourceFromFile returns an InputSourceContext suitable for retrieving config variables from a file (or url) containing JSON data. func NewJSONSourceFromReader(r io.Reader) (InputSourceContext, error) NewJSONSourceFromReader returns an InputSourceContext suitable for retrieving config variables from an io.Reader that returns JSON data. func NewTomlSourceFromFile(file string) (InputSourceContext, error) NewTomlSourceFromFile creates a new TOML InputSourceContext from a filepath. func NewYamlSourceFromFile(file string) (InputSourceContext, error) NewYamlSourceFromFile creates a new Yaml InputSourceContext from a filepath. type Int64Flag struct { *cli.Int64Flag // Has unexported fields. } Int64Flag is the flag type that wraps cli.Int64Flag to allow for other values to be specified func NewInt64Flag(fl *cli.Int64Flag) *Int64Flag NewInt64Flag creates a new Int64Flag func (f *Int64Flag) Apply(set *flag.FlagSet) error Apply saves the flagSet for later usage calls, then calls the wrapped Int64Flag.Apply type Int64SliceFlag struct { *cli.Int64SliceFlag // Has unexported fields. } Int64SliceFlag is the flag type that wraps cli.Int64SliceFlag to allow for other values to be specified func NewInt64SliceFlag(fl *cli.Int64SliceFlag) *Int64SliceFlag NewInt64SliceFlag creates a new Int64SliceFlag func (f *Int64SliceFlag) Apply(set *flag.FlagSet) error Apply saves the flagSet for later usage calls, then calls the wrapped Int64SliceFlag.Apply type IntFlag struct { *cli.IntFlag // Has unexported fields. } IntFlag is the flag type that wraps cli.IntFlag to allow for other values to be specified func NewIntFlag(fl *cli.IntFlag) *IntFlag NewIntFlag creates a new IntFlag func (f *IntFlag) Apply(set *flag.FlagSet) error Apply saves the flagSet for later usage calls, then calls the wrapped IntFlag.Apply func (f *IntFlag) ApplyInputSourceValue(cCtx *cli.Context, isc InputSourceContext) error ApplyInputSourceValue applies a int value to the flagSet if required type IntSliceFlag struct { *cli.IntSliceFlag // Has unexported fields. } IntSliceFlag is the flag type that wraps cli.IntSliceFlag to allow for other values to be specified func NewIntSliceFlag(fl *cli.IntSliceFlag) *IntSliceFlag NewIntSliceFlag creates a new IntSliceFlag func (f *IntSliceFlag) Apply(set *flag.FlagSet) error Apply saves the flagSet for later usage calls, then calls the wrapped IntSliceFlag.Apply func (f *IntSliceFlag) ApplyInputSourceValue(cCtx *cli.Context, isc InputSourceContext) error ApplyInputSourceValue applies a IntSlice value if required type MapInputSource struct { // Has unexported fields. } MapInputSource implements InputSourceContext to return data from the map that is loaded. func NewMapInputSource(file string, valueMap map[interface{}]interface{}) *MapInputSource NewMapInputSource creates a new MapInputSource for implementing custom input sources. func (fsm *MapInputSource) Bool(name string) (bool, error) Bool returns an bool from the map otherwise returns false func (fsm *MapInputSource) Duration(name string) (time.Duration, error) Duration returns a duration from the map if it exists otherwise returns 0 func (fsm *MapInputSource) Float64(name string) (float64, error) Float64 returns an float64 from the map if it exists otherwise returns 0 func (fsm *MapInputSource) Generic(name string) (cli.Generic, error) Generic returns an cli.Generic from the map if it exists otherwise returns nil func (fsm *MapInputSource) Int(name string) (int, error) Int returns an int from the map if it exists otherwise returns 0 func (fsm *MapInputSource) IntSlice(name string) ([]int, error) IntSlice returns an []int from the map if it exists otherwise returns nil func (fsm *MapInputSource) Source() string Source returns the path of the source file func (fsm *MapInputSource) String(name string) (string, error) String returns a string from the map if it exists otherwise returns an empty string func (fsm *MapInputSource) StringSlice(name string) ([]string, error) StringSlice returns an []string from the map if it exists otherwise returns nil type PathFlag struct { *cli.PathFlag // Has unexported fields. } PathFlag is the flag type that wraps cli.PathFlag to allow for other values to be specified func NewPathFlag(fl *cli.PathFlag) *PathFlag NewPathFlag creates a new PathFlag func (f *PathFlag) Apply(set *flag.FlagSet) error Apply saves the flagSet for later usage calls, then calls the wrapped PathFlag.Apply func (f *PathFlag) ApplyInputSourceValue(cCtx *cli.Context, isc InputSourceContext) error ApplyInputSourceValue applies a Path value to the flagSet if required type StringFlag struct { *cli.StringFlag // Has unexported fields. } StringFlag is the flag type that wraps cli.StringFlag to allow for other values to be specified func NewStringFlag(fl *cli.StringFlag) *StringFlag NewStringFlag creates a new StringFlag func (f *StringFlag) Apply(set *flag.FlagSet) error Apply saves the flagSet for later usage calls, then calls the wrapped StringFlag.Apply func (f *StringFlag) ApplyInputSourceValue(cCtx *cli.Context, isc InputSourceContext) error ApplyInputSourceValue applies a String value to the flagSet if required type StringSliceFlag struct { *cli.StringSliceFlag // Has unexported fields. } StringSliceFlag is the flag type that wraps cli.StringSliceFlag to allow for other values to be specified func NewStringSliceFlag(fl *cli.StringSliceFlag) *StringSliceFlag NewStringSliceFlag creates a new StringSliceFlag func (f *StringSliceFlag) Apply(set *flag.FlagSet) error Apply saves the flagSet for later usage calls, then calls the wrapped StringSliceFlag.Apply func (f *StringSliceFlag) ApplyInputSourceValue(cCtx *cli.Context, isc InputSourceContext) error ApplyInputSourceValue applies a StringSlice value to the flagSet if required type Uint64Flag struct { *cli.Uint64Flag // Has unexported fields. } Uint64Flag is the flag type that wraps cli.Uint64Flag to allow for other values to be specified func NewUint64Flag(fl *cli.Uint64Flag) *Uint64Flag NewUint64Flag creates a new Uint64Flag func (f *Uint64Flag) Apply(set *flag.FlagSet) error Apply saves the flagSet for later usage calls, then calls the wrapped Uint64Flag.Apply type UintFlag struct { *cli.UintFlag // Has unexported fields. } UintFlag is the flag type that wraps cli.UintFlag to allow for other values to be specified func NewUintFlag(fl *cli.UintFlag) *UintFlag NewUintFlag creates a new UintFlag func (f *UintFlag) Apply(set *flag.FlagSet) error Apply saves the flagSet for later usage calls, then calls the wrapped UintFlag.Apply