Struct FlagSet

flag.go:156–191

A FlagSet represents a set of defined flags.

// A FlagSet represents a set of defined flags.
type FlagSet struct {
	// Usage is the function called when an error occurs while parsing flags.
	// The field is a function (not a method) that may be changed to point to
	// a custom error handler.
	Usage func()

	// SortFlags is used to indicate, if user wants to have sorted flags in
	// help/usage messages.
	SortFlags bool

	// ParseErrorsAllowlist is used to configure an allowlist of errors
	ParseErrorsAllowlist ParseErrorsAllowlist

	// ParseErrorsAllowlist is used to configure an allowlist of errors.
	//
	// Deprecated: use [FlagSet.ParseErrorsAllowlist] instead. This field will be removed in a future release.
	ParseErrorsWhitelist ParseErrorsAllowlist

	name              string
	parsed            bool
	actual            map[NormalizedName]*Flag
	orderedActual     []*Flag
	sortedActual      []*Flag
	formal            map[NormalizedName]*Flag
	orderedFormal     []*Flag
	sortedFormal      []*Flag
	shorthands        map[byte]*Flag
	args              []string // arguments after flags
	argsLenAtDash     int      // len(args) when a '--' was located when parsing, or -1 if no --
	errorHandling     ErrorHandling
	output            io.Writer // nil means stderr; use Output() accessor
	interspersed      bool      // allow interspersed option/non-option args
	normalizeNameFunc func(f *FlagSet, name string) NormalizedName

	addedGoFlagSets []*goflag.FlagSet
}

// A Flag represents the state of a flag.
type Flag struct {