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+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+Package pflag is a drop-in replacement for Go's flag package, implementing
+POSIX/GNU-style --flags.
+
+pflag is compatible with the GNU extensions to the POSIX recommendations
+for command-line options. See
+http://www.gnu.org/software/libc/manual/html_node/Argument-Syntax.html
+
+Usage:
+
+pflag is a drop-in replacement of Go's native flag package. If you import
+pflag under the name "flag" then all code should continue to function
+with no changes.
+
+ import flag "github.com/ogier/pflag"
+
+ There is one exception to this: if you directly instantiate the Flag struct
+there is one more field "Shorthand" that you will need to set.
+Most code never instantiates this struct directly, and instead uses
+functions such as String(), BoolVar(), and Var(), and is therefore
+unaffected.
+
+Define flags using flag.String(), Bool(), Int(), etc.
+
+This declares an integer flag, -flagname, stored in the pointer ip, with type *int.
+ var ip = flag.Int("flagname", 1234, "help message for flagname")
+If you like, you can bind the flag to a variable using the Var() functions.
+ var flagvar int
+ func init() {
+ flag.IntVar(&flagvar, "flagname", 1234, "help message for flagname")
+ }
+Or you can create custom flags that satisfy the Value interface (with
+pointer receivers) and couple them to flag parsing by
+ flag.Var(&flagVal, "name", "help message for flagname")
+For such flags, the default value is just the initial value of the variable.
+
+After all flags are defined, call
+ flag.Parse()
+to parse the command line into the defined flags.
+
+Flags may then be used directly. If you're using the flags themselves,
+they are all pointers; if you bind to variables, they're values.
+ fmt.Println("ip has value ", *ip)
+ fmt.Println("flagvar has value ", flagvar)
+
+After parsing, the arguments after the flag are available as the
+slice flag.Args() or individually as flag.Arg(i).
+The arguments are indexed from 0 through flag.NArg()-1.
+
+The pflag package also defines some new functions that are not in flag,
+that give one-letter shorthands for flags. You can use these by appending
+'P' to the name of any function that defines a flag.
+ var ip = flag.IntP("flagname", "f", 1234, "help message")
+ var flagvar bool
+ func init() {
+ flag.BoolVarP("boolname", "b", true, "help message")
+ }
+ flag.VarP(&flagVar, "varname", "v", 1234, "help message")
+Shorthand letters can be used with single dashes on the command line.
+Boolean shorthand flags can be combined with other shorthand flags.
+
+Command line flag syntax:
+ --flag // boolean flags only
+ --flag=x
+
+Unlike the flag package, a single dash before an option means something
+different than a double dash. Single dashes signify a series of shorthand
+letters for flags. All but the last shorthand letter must be boolean flags.
+ // boolean flags
+ -f
+ -abc
+ // non-boolean flags
+ -n 1234
+ -Ifile
+ // mixed
+ -abcs "hello"
+ -abcn1234
+
+Flag parsing stops after the terminator "--". Unlike the flag package,
+flags can be interspersed with arguments anywhere on the command line
+before this terminator.
+
+Integer flags accept 1234, 0664, 0x1234 and may be negative.
+Boolean flags (in their long form) accept 1, 0, t, f, true, false,
+TRUE, FALSE, True, False.
+Duration flags accept any input valid for time.ParseDuration.
+
+The default set of command-line flags is controlled by
+top-level functions. The FlagSet type allows one to define
+independent sets of flags, such as to implement subcommands
+in a command-line interface. The methods of FlagSet are
+analogous to the top-level functions for the command-line
+flag set.
+*/
+package pflag
+
+import (
+ "bytes"
+ "errors"
+ "fmt"
+ "io"
+ "os"
+ "sort"
+ "strings"
+)
+
+// ErrHelp is the error returned if the flag -help is invoked but no such flag is defined.
+var ErrHelp = errors.New("pflag: help requested")
+
+// ErrorHandling defines how to handle flag parsing errors.
+type ErrorHandling int
+
+const (
+ // ContinueOnError will return an err from Parse() if an error is found
+ ContinueOnError ErrorHandling = iota
+ // ExitOnError will call os.Exit(2) if an error is found when parsing
+ ExitOnError
+ // PanicOnError will panic() if an error is found when parsing flags
+ PanicOnError
+)
+
+// NormalizedName is a flag name that has been normalized according to rules
+// for the FlagSet (e.g. making '-' and '_' equivalent).
+type NormalizedName string
+
+// 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()
+
+ name string
+ parsed bool
+ actual map[NormalizedName]*Flag
+ formal map[NormalizedName]*Flag
+ shorthands map[byte]*Flag
+ args []string // arguments after flags
+ argsLenAtDash int // len(args) when a '--' was located when parsing, or -1 if no --
+ exitOnError bool // does the program exit if there's an error?
+ errorHandling ErrorHandling
+ output io.Writer // nil means stderr; use out() accessor
+ interspersed bool // allow interspersed option/non-option args
+ normalizeNameFunc func(f *FlagSet, name string) NormalizedName
+}
+
+// A Flag represents the state of a flag.
+type Flag struct {
+ Name string // name as it appears on command line
+ Shorthand string // one-letter abbreviated flag
+ Usage string // help message
+ Value Value // value as set
+ DefValue string // default value (as text); for usage message
+ Changed bool // If the user set the value (or if left to default)
+ NoOptDefVal string //default value (as text); if the flag is on the command line without any options
+ Deprecated string // If this flag is deprecated, this string is the new or now thing to use
+ Hidden bool // used by cobra.Command to allow flags to be hidden from help/usage text
+ ShorthandDeprecated string // If the shorthand of this flag is deprecated, this string is the new or now thing to use
+ Annotations map[string][]string // used by cobra.Command bash autocomple code
+}
+
+// Value is the interface to the dynamic value stored in a flag.
+// (The default value is represented as a string.)
+type Value interface {
+ String() string
+ Set(string) error
+ Type() string
+}
+
+// sortFlags returns the flags as a slice in lexicographical sorted order.
+func sortFlags(flags map[NormalizedName]*Flag) []*Flag {
+ list := make(sort.StringSlice, len(flags))
+ i := 0
+ for k := range flags {
+ list[i] = string(k)
+ i++
+ }
+ list.Sort()
+ result := make([]*Flag, len(list))
+ for i, name := range list {
+ result[i] = flags[NormalizedName(name)]
+ }
+ return result
+}
+
+// SetNormalizeFunc allows you to add a function which can translate flag names.
+// Flags added to the FlagSet will be translated and then when anything tries to
+// look up the flag that will also be translated. So it would be possible to create
+// a flag named "getURL" and have it translated to "geturl". A user could then pass
+// "--getUrl" which may also be translated to "geturl" and everything will work.
+func (f *FlagSet) SetNormalizeFunc(n func(f *FlagSet, name string) NormalizedName) {
+ f.normalizeNameFunc = n
+ for k, v := range f.formal {
+ delete(f.formal, k)
+ nname := f.normalizeFlagName(string(k))
+ f.formal[nname] = v
+ v.Name = string(nname)
+ }
+}
+
+// GetNormalizeFunc returns the previously set NormalizeFunc of a function which
+// does no translation, if not set previously.
+func (f *FlagSet) GetNormalizeFunc() func(f *FlagSet, name string) NormalizedName {
+ if f.normalizeNameFunc != nil {
+ return f.normalizeNameFunc
+ }
+ return func(f *FlagSet, name string) NormalizedName { return NormalizedName(name) }
+}
+
+func (f *FlagSet) normalizeFlagName(name string) NormalizedName {
+ n := f.GetNormalizeFunc()
+ return n(f, name)
+}
+
+func (f *FlagSet) out() io.Writer {
+ if f.output == nil {
+ return os.Stderr
+ }
+ return f.output
+}
+
+// SetOutput sets the destination for usage and error messages.
+// If output is nil, os.Stderr is used.
+func (f *FlagSet) SetOutput(output io.Writer) {
+ f.output = output
+}
+
+// VisitAll visits the flags in lexicographical order, calling fn for each.
+// It visits all flags, even those not set.
+func (f *FlagSet) VisitAll(fn func(*Flag)) {
+ for _, flag := range sortFlags(f.formal) {
+ fn(flag)
+ }
+}
+
+// HasFlags returns a bool to indicate if the FlagSet has any flags definied.
+func (f *FlagSet) HasFlags() bool {
+ return len(f.formal) > 0
+}
+
+// HasAvailableFlags returns a bool to indicate if the FlagSet has any flags
+// definied that are not hidden or deprecated.
+func (f *FlagSet) HasAvailableFlags() bool {
+ for _, flag := range f.formal {
+ if !flag.Hidden && len(flag.Deprecated) == 0 {
+ return true
+ }
+ }
+ return false
+}
+
+// VisitAll visits the command-line flags in lexicographical order, calling
+// fn for each. It visits all flags, even those not set.
+func VisitAll(fn func(*Flag)) {
+ CommandLine.VisitAll(fn)
+}
+
+// Visit visits the flags in lexicographical order, calling fn for each.
+// It visits only those flags that have been set.
+func (f *FlagSet) Visit(fn func(*Flag)) {
+ for _, flag := range sortFlags(f.actual) {
+ fn(flag)
+ }
+}
+
+// Visit visits the command-line flags in lexicographical order, calling fn
+// for each. It visits only those flags that have been set.
+func Visit(fn func(*Flag)) {
+ CommandLine.Visit(fn)
+}
+
+// Lookup returns the Flag structure of the named flag, returning nil if none exists.
+func (f *FlagSet) Lookup(name string) *Flag {
+ return f.lookup(f.normalizeFlagName(name))
+}
+
+// lookup returns the Flag structure of the named flag, returning nil if none exists.
+func (f *FlagSet) lookup(name NormalizedName) *Flag {
+ return f.formal[name]
+}
+
+// func to return a given type for a given flag name
+func (f *FlagSet) getFlagType(name string, ftype string, convFunc func(sval string) (interface{}, error)) (interface{}, error) {
+ flag := f.Lookup(name)
+ if flag == nil {
+ err := fmt.Errorf("flag accessed but not defined: %s", name)
+ return nil, err
+ }
+
+ if flag.Value.Type() != ftype {
+ err := fmt.Errorf("trying to get %s value of flag of type %s", ftype, flag.Value.Type())
+ return nil, err
+ }
+
+ sval := flag.Value.String()
+ result, err := convFunc(sval)
+ if err != nil {
+ return nil, err
+ }
+ return result, nil
+}
+
+// ArgsLenAtDash will return the length of f.Args at the moment when a -- was
+// found during arg parsing. This allows your program to know which args were
+// before the -- and which came after.
+func (f *FlagSet) ArgsLenAtDash() int {
+ return f.argsLenAtDash
+}
+
+// MarkDeprecated indicated that a flag is deprecated in your program. It will
+// continue to function but will not show up in help or usage messages. Using
+// this flag will also print the given usageMessage.
+func (f *FlagSet) MarkDeprecated(name string, usageMessage string) error {
+ flag := f.Lookup(name)
+ if flag == nil {
+ return fmt.Errorf("flag %q does not exist", name)
+ }
+ if len(usageMessage) == 0 {
+ return fmt.Errorf("deprecated message for flag %q must be set", name)
+ }
+ flag.Deprecated = usageMessage
+ return nil
+}
+
+// MarkShorthandDeprecated will mark the shorthand of a flag deprecated in your
+// program. It will continue to function but will not show up in help or usage
+// messages. Using this flag will also print the given usageMessage.
+func (f *FlagSet) MarkShorthandDeprecated(name string, usageMessage string) error {
+ flag := f.Lookup(name)
+ if flag == nil {
+ return fmt.Errorf("flag %q does not exist", name)
+ }
+ if len(usageMessage) == 0 {
+ return fmt.Errorf("deprecated message for flag %q must be set", name)
+ }
+ flag.ShorthandDeprecated = usageMessage
+ return nil
+}
+
+// MarkHidden sets a flag to 'hidden' in your program. It will continue to
+// function but will not show up in help or usage messages.
+func (f *FlagSet) MarkHidden(name string) error {
+ flag := f.Lookup(name)
+ if flag == nil {
+ return fmt.Errorf("flag %q does not exist", name)
+ }
+ flag.Hidden = true
+ return nil
+}
+
+// Lookup returns the Flag structure of the named command-line flag,
+// returning nil if none exists.
+func Lookup(name string) *Flag {
+ return CommandLine.Lookup(name)
+}
+
+// Set sets the value of the named flag.
+func (f *FlagSet) Set(name, value string) error {
+ normalName := f.normalizeFlagName(name)
+ flag, ok := f.formal[normalName]
+ if !ok {
+ return fmt.Errorf("no such flag -%v", name)
+ }
+ err := flag.Value.Set(value)
+ if err != nil {
+ return err
+ }
+ if f.actual == nil {
+ f.actual = make(map[NormalizedName]*Flag)
+ }
+ f.actual[normalName] = flag
+ flag.Changed = true
+ if len(flag.Deprecated) > 0 {
+ fmt.Fprintf(os.Stderr, "Flag --%s has been deprecated, %s\n", flag.Name, flag.Deprecated)
+ }
+ return nil
+}
+
+// SetAnnotation allows one to set arbitrary annotations on a flag in the FlagSet.
+// This is sometimes used by spf13/cobra programs which want to generate additional
+// bash completion information.
+func (f *FlagSet) SetAnnotation(name, key string, values []string) error {
+ normalName := f.normalizeFlagName(name)
+ flag, ok := f.formal[normalName]
+ if !ok {
+ return fmt.Errorf("no such flag -%v", name)
+ }
+ if flag.Annotations == nil {
+ flag.Annotations = map[string][]string{}
+ }
+ flag.Annotations[key] = values
+ return nil
+}
+
+// Changed returns true if the flag was explicitly set during Parse() and false
+// otherwise
+func (f *FlagSet) Changed(name string) bool {
+ flag := f.Lookup(name)
+ // If a flag doesn't exist, it wasn't changed....
+ if flag == nil {
+ return false
+ }
+ return flag.Changed
+}
+
+// Set sets the value of the named command-line flag.
+func Set(name, value string) error {
+ return CommandLine.Set(name, value)
+}
+
+// PrintDefaults prints, to standard error unless configured
+// otherwise, the default values of all defined flags in the set.
+func (f *FlagSet) PrintDefaults() {
+ usages := f.FlagUsages()
+ fmt.Fprintf(f.out(), "%s", usages)
+}
+
+// isZeroValue guesses whether the string represents the zero
+// value for a flag. It is not accurate but in practice works OK.
+func isZeroValue(value string) bool {
+ switch value {
+ case "false":
+ return true
+ case "<nil>":
+ return true
+ case "":
+ return true
+ case "0":
+ return true
+ }
+ return false
+}
+
+// UnquoteUsage extracts a back-quoted name from the usage
+// string for a flag and returns it and the un-quoted usage.
+// Given "a `name` to show" it returns ("name", "a name to show").
+// If there are no back quotes, the name is an educated guess of the
+// type of the flag's value, or the empty string if the flag is boolean.
+func UnquoteUsage(flag *Flag) (name string, usage string) {
+ // Look for a back-quoted name, but avoid the strings package.
+ usage = flag.Usage
+ for i := 0; i < len(usage); i++ {
+ if usage[i] == '`' {
+ for j := i + 1; j < len(usage); j++ {
+ if usage[j] == '`' {
+ name = usage[i+1 : j]
+ usage = usage[:i] + name + usage[j+1:]
+ return name, usage
+ }
+ }
+ break // Only one back quote; use type name.
+ }
+ }
+ // No explicit name, so use type if we can find one.
+ name = "value"
+ switch flag.Value.(type) {
+ case boolFlag:
+ name = ""
+ case *durationValue:
+ name = "duration"
+ case *float64Value:
+ name = "float"
+ case *intValue, *int64Value:
+ name = "int"
+ case *stringValue:
+ name = "string"
+ case *uintValue, *uint64Value:
+ name = "uint"
+ }
+ return
+}
+
+// FlagUsages Returns a string containing the usage information for all flags in
+// the FlagSet
+func (f *FlagSet) FlagUsages() string {
+ x := new(bytes.Buffer)
+
+ lines := make([]string, 0, len(f.formal))
+
+ maxlen := 0
+ f.VisitAll(func(flag *Flag) {
+ if len(flag.Deprecated) > 0 || flag.Hidden {
+ return
+ }
+
+ line := ""
+ if len(flag.Shorthand) > 0 && len(flag.ShorthandDeprecated) == 0 {
+ line = fmt.Sprintf(" -%s, --%s", flag.Shorthand, flag.Name)
+ } else {
+ line = fmt.Sprintf(" --%s", flag.Name)
+ }
+
+ varname, usage := UnquoteUsage(flag)
+ if len(varname) > 0 {
+ line += " " + varname
+ }
+ if len(flag.NoOptDefVal) > 0 {
+ switch flag.Value.Type() {
+ case "string":
+ line += fmt.Sprintf("[=%q]", flag.NoOptDefVal)
+ case "bool":
+ if flag.NoOptDefVal != "true" {
+ line += fmt.Sprintf("[=%s]", flag.NoOptDefVal)
+ }
+ default:
+ line += fmt.Sprintf("[=%s]", flag.NoOptDefVal)
+ }
+ }
+
+ // This special character will be replaced with spacing once the
+ // correct alignment is calculated
+ line += "\x00"
+ if len(line) > maxlen {
+ maxlen = len(line)
+ }
+
+ line += usage
+ if !isZeroValue(flag.DefValue) {
+ if flag.Value.Type() == "string" {
+ line += fmt.Sprintf(" (default %q)", flag.DefValue)
+ } else {
+ line += fmt.Sprintf(" (default %s)", flag.DefValue)
+ }
+ }
+
+ lines = append(lines, line)
+ })
+
+ for _, line := range lines {
+ sidx := strings.Index(line, "\x00")
+ spacing := strings.Repeat(" ", maxlen-sidx)
+ fmt.Fprintln(x, line[:sidx], spacing, line[sidx+1:])
+ }
+
+ return x.String()
+}
+
+// PrintDefaults prints to standard error the default values of all defined command-line flags.
+func PrintDefaults() {
+ CommandLine.PrintDefaults()
+}
+
+// defaultUsage is the default function to print a usage message.
+func defaultUsage(f *FlagSet) {
+ fmt.Fprintf(f.out(), "Usage of %s:\n", f.name)
+ f.PrintDefaults()
+}
+
+// NOTE: Usage is not just defaultUsage(CommandLine)
+// because it serves (via godoc flag Usage) as the example
+// for how to write your own usage function.
+
+// Usage prints to standard error a usage message documenting all defined command-line flags.
+// The function is a variable that may be changed to point to a custom function.
+// By default it prints a simple header and calls PrintDefaults; for details about the
+// format of the output and how to control it, see the documentation for PrintDefaults.
+var Usage = func() {
+ fmt.Fprintf(os.Stderr, "Usage of %s:\n", os.Args[0])
+ PrintDefaults()
+}
+
+// NFlag returns the number of flags that have been set.
+func (f *FlagSet) NFlag() int { return len(f.actual) }
+
+// NFlag returns the number of command-line flags that have been set.
+func NFlag() int { return len(CommandLine.actual) }
+
+// Arg returns the i'th argument. Arg(0) is the first remaining argument
+// after flags have been processed.
+func (f *FlagSet) Arg(i int) string {
+ if i < 0 || i >= len(f.args) {
+ return ""
+ }
+ return f.args[i]
+}
+
+// Arg returns the i'th command-line argument. Arg(0) is the first remaining argument
+// after flags have been processed.
+func Arg(i int) string {
+ return CommandLine.Arg(i)
+}
+
+// NArg is the number of arguments remaining after flags have been processed.
+func (f *FlagSet) NArg() int { return len(f.args) }
+
+// NArg is the number of arguments remaining after flags have been processed.
+func NArg() int { return len(CommandLine.args) }
+
+// Args returns the non-flag arguments.
+func (f *FlagSet) Args() []string { return f.args }
+
+// Args returns the non-flag command-line arguments.
+func Args() []string { return CommandLine.args }
+
+// Var defines a flag with the specified name and usage string. The type and
+// value of the flag are represented by the first argument, of type Value, which
+// typically holds a user-defined implementation of Value. For instance, the
+// caller could create a flag that turns a comma-separated string into a slice
+// of strings by giving the slice the methods of Value; in particular, Set would
+// decompose the comma-separated string into the slice.
+func (f *FlagSet) Var(value Value, name string, usage string) {
+ f.VarP(value, name, "", usage)
+}
+
+// VarPF is like VarP, but returns the flag created
+func (f *FlagSet) VarPF(value Value, name, shorthand, usage string) *Flag {
+ // Remember the default value as a string; it won't change.
+ flag := &Flag{
+ Name: name,
+ Shorthand: shorthand,
+ Usage: usage,
+ Value: value,
+ DefValue: value.String(),
+ }
+ f.AddFlag(flag)
+ return flag
+}
+
+// VarP is like Var, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) VarP(value Value, name, shorthand, usage string) {
+ _ = f.VarPF(value, name, shorthand, usage)
+}
+
+// AddFlag will add the flag to the FlagSet
+func (f *FlagSet) AddFlag(flag *Flag) {
+ // Call normalizeFlagName function only once
+ normalizedFlagName := f.normalizeFlagName(flag.Name)
+
+ _, alreadythere := f.formal[normalizedFlagName]
+ if alreadythere {
+ msg := fmt.Sprintf("%s flag redefined: %s", f.name, flag.Name)
+ fmt.Fprintln(f.out(), msg)
+ panic(msg) // Happens only if flags are declared with identical names
+ }
+ if f.formal == nil {
+ f.formal = make(map[NormalizedName]*Flag)
+ }
+
+ flag.Name = string(normalizedFlagName)
+ f.formal[normalizedFlagName] = flag
+
+ if len(flag.Shorthand) == 0 {
+ return
+ }
+ if len(flag.Shorthand) > 1 {
+ fmt.Fprintf(f.out(), "%s shorthand more than ASCII character: %s\n", f.name, flag.Shorthand)
+ panic("shorthand is more than one character")
+ }
+ if f.shorthands == nil {
+ f.shorthands = make(map[byte]*Flag)
+ }
+ c := flag.Shorthand[0]
+ old, alreadythere := f.shorthands[c]
+ if alreadythere {
+ fmt.Fprintf(f.out(), "%s shorthand reused: %q for %s already used for %s\n", f.name, c, flag.Name, old.Name)
+ panic("shorthand redefinition")
+ }
+ f.shorthands[c] = flag
+}
+
+// AddFlagSet adds one FlagSet to another. If a flag is already present in f
+// the flag from newSet will be ignored
+func (f *FlagSet) AddFlagSet(newSet *FlagSet) {
+ if newSet == nil {
+ return
+ }
+ newSet.VisitAll(func(flag *Flag) {
+ if f.Lookup(flag.Name) == nil {
+ f.AddFlag(flag)
+ }
+ })
+}
+
+// Var defines a flag with the specified name and usage string. The type and
+// value of the flag are represented by the first argument, of type Value, which
+// typically holds a user-defined implementation of Value. For instance, the
+// caller could create a flag that turns a comma-separated string into a slice
+// of strings by giving the slice the methods of Value; in particular, Set would
+// decompose the comma-separated string into the slice.
+func Var(value Value, name string, usage string) {
+ CommandLine.VarP(value, name, "", usage)
+}
+
+// VarP is like Var, but accepts a shorthand letter that can be used after a single dash.
+func VarP(value Value, name, shorthand, usage string) {
+ CommandLine.VarP(value, name, shorthand, usage)
+}
+
+// failf prints to standard error a formatted error and usage message and
+// returns the error.
+func (f *FlagSet) failf(format string, a ...interface{}) error {
+ err := fmt.Errorf(format, a...)
+ fmt.Fprintln(f.out(), err)
+ f.usage()
+ return err
+}
+
+// usage calls the Usage method for the flag set, or the usage function if
+// the flag set is CommandLine.
+func (f *FlagSet) usage() {
+ if f == CommandLine {
+ Usage()
+ } else if f.Usage == nil {
+ defaultUsage(f)
+ } else {
+ f.Usage()
+ }
+}
+
+func (f *FlagSet) setFlag(flag *Flag, value string, origArg string) error {
+ if err := flag.Value.Set(value); err != nil {
+ return f.failf("invalid argument %q for %s: %v", value, origArg, err)
+ }
+ // mark as visited for Visit()
+ if f.actual == nil {
+ f.actual = make(map[NormalizedName]*Flag)
+ }
+ f.actual[f.normalizeFlagName(flag.Name)] = flag
+ flag.Changed = true
+ if len(flag.Deprecated) > 0 {
+ fmt.Fprintf(os.Stderr, "Flag --%s has been deprecated, %s\n", flag.Name, flag.Deprecated)
+ }
+ if len(flag.ShorthandDeprecated) > 0 && containsShorthand(origArg, flag.Shorthand) {
+ fmt.Fprintf(os.Stderr, "Flag shorthand -%s has been deprecated, %s\n", flag.Shorthand, flag.ShorthandDeprecated)
+ }
+ return nil
+}
+
+func containsShorthand(arg, shorthand string) bool {
+ // filter out flags --<flag_name>
+ if strings.HasPrefix(arg, "-") {
+ return false
+ }
+ arg = strings.SplitN(arg, "=", 2)[0]
+ return strings.Contains(arg, shorthand)
+}
+
+func (f *FlagSet) parseLongArg(s string, args []string) (a []string, err error) {
+ a = args
+ name := s[2:]
+ if len(name) == 0 || name[0] == '-' || name[0] == '=' {
+ err = f.failf("bad flag syntax: %s", s)
+ return
+ }
+ split := strings.SplitN(name, "=", 2)
+ name = split[0]
+ flag, alreadythere := f.formal[f.normalizeFlagName(name)]
+ if !alreadythere {
+ if name == "help" { // special case for nice help message.
+ f.usage()
+ return a, ErrHelp
+ }
+ err = f.failf("unknown flag: --%s", name)
+ return
+ }
+ var value string
+ if len(split) == 2 {
+ // '--flag=arg'
+ value = split[1]
+ } else if len(flag.NoOptDefVal) > 0 {
+ // '--flag' (arg was optional)
+ value = flag.NoOptDefVal
+ } else if len(a) > 0 {
+ // '--flag arg'
+ value = a[0]
+ a = a[1:]
+ } else {
+ // '--flag' (arg was required)
+ err = f.failf("flag needs an argument: %s", s)
+ return
+ }
+ err = f.setFlag(flag, value, s)
+ return
+}
+
+func (f *FlagSet) parseSingleShortArg(shorthands string, args []string) (outShorts string, outArgs []string, err error) {
+ if strings.HasPrefix(shorthands, "test.") {
+ return
+ }
+ outArgs = args
+ outShorts = shorthands[1:]
+ c := shorthands[0]
+
+ flag, alreadythere := f.shorthands[c]
+ if !alreadythere {
+ if c == 'h' { // special case for nice help message.
+ f.usage()
+ err = ErrHelp
+ return
+ }
+ //TODO continue on error
+ err = f.failf("unknown shorthand flag: %q in -%s", c, shorthands)
+ return
+ }
+ var value string
+ if len(shorthands) > 2 && shorthands[1] == '=' {
+ value = shorthands[2:]
+ outShorts = ""
+ } else if len(flag.NoOptDefVal) > 0 {
+ value = flag.NoOptDefVal
+ } else if len(shorthands) > 1 {
+ value = shorthands[1:]
+ outShorts = ""
+ } else if len(args) > 0 {
+ value = args[0]
+ outArgs = args[1:]
+ } else {
+ err = f.failf("flag needs an argument: %q in -%s", c, shorthands)
+ return
+ }
+ err = f.setFlag(flag, value, shorthands)
+ return
+}
+
+func (f *FlagSet) parseShortArg(s string, args []string) (a []string, err error) {
+ a = args
+ shorthands := s[1:]
+
+ for len(shorthands) > 0 {
+ shorthands, a, err = f.parseSingleShortArg(shorthands, args)
+ if err != nil {
+ return
+ }
+ }
+
+ return
+}
+
+func (f *FlagSet) parseArgs(args []string) (err error) {
+ for len(args) > 0 {
+ s := args[0]
+ args = args[1:]
+ if len(s) == 0 || s[0] != '-' || len(s) == 1 {
+ if !f.interspersed {
+ f.args = append(f.args, s)
+ f.args = append(f.args, args...)
+ return nil
+ }
+ f.args = append(f.args, s)
+ continue
+ }
+
+ if s[1] == '-' {
+ if len(s) == 2 { // "--" terminates the flags
+ f.argsLenAtDash = len(f.args)
+ f.args = append(f.args, args...)
+ break
+ }
+ args, err = f.parseLongArg(s, args)
+ } else {
+ args, err = f.parseShortArg(s, args)
+ }
+ if err != nil {
+ return
+ }
+ }
+ return
+}
+
+// Parse parses flag definitions from the argument list, which should not
+// include the command name. Must be called after all flags in the FlagSet
+// are defined and before flags are accessed by the program.
+// The return value will be ErrHelp if -help was set but not defined.
+func (f *FlagSet) Parse(arguments []string) error {
+ f.parsed = true
+ f.args = make([]string, 0, len(arguments))
+ err := f.parseArgs(arguments)
+ if err != nil {
+ switch f.errorHandling {
+ case ContinueOnError:
+ return err
+ case ExitOnError:
+ os.Exit(2)
+ case PanicOnError:
+ panic(err)
+ }
+ }
+ return nil
+}
+
+// Parsed reports whether f.Parse has been called.
+func (f *FlagSet) Parsed() bool {
+ return f.parsed
+}
+
+// Parse parses the command-line flags from os.Args[1:]. Must be called
+// after all flags are defined and before flags are accessed by the program.
+func Parse() {
+ // Ignore errors; CommandLine is set for ExitOnError.
+ CommandLine.Parse(os.Args[1:])
+}
+
+// SetInterspersed sets whether to support interspersed option/non-option arguments.
+func SetInterspersed(interspersed bool) {
+ CommandLine.SetInterspersed(interspersed)
+}
+
+// Parsed returns true if the command-line flags have been parsed.
+func Parsed() bool {
+ return CommandLine.Parsed()
+}
+
+// CommandLine is the default set of command-line flags, parsed from os.Args.
+var CommandLine = NewFlagSet(os.Args[0], ExitOnError)
+
+// NewFlagSet returns a new, empty flag set with the specified name and
+// error handling property.
+func NewFlagSet(name string, errorHandling ErrorHandling) *FlagSet {
+ f := &FlagSet{
+ name: name,
+ errorHandling: errorHandling,
+ argsLenAtDash: -1,
+ interspersed: true,
+ }
+ return f
+}
+
+// SetInterspersed sets whether to support interspersed option/non-option arguments.
+func (f *FlagSet) SetInterspersed(interspersed bool) {
+ f.interspersed = interspersed
+}
+
+// Init sets the name and error handling property for a flag set.
+// By default, the zero FlagSet uses an empty name and the
+// ContinueOnError error handling policy.
+func (f *FlagSet) Init(name string, errorHandling ErrorHandling) {
+ f.name = name
+ f.errorHandling = errorHandling
+ f.argsLenAtDash = -1
+}