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Diffstat (limited to 'vendor/github.com/spf13/pflag/flag.go')
| -rw-r--r-- | vendor/github.com/spf13/pflag/flag.go | 1157 |
1 files changed, 1157 insertions, 0 deletions
diff --git a/vendor/github.com/spf13/pflag/flag.go b/vendor/github.com/spf13/pflag/flag.go new file mode 100644 index 00000000..28538c07 --- /dev/null +++ b/vendor/github.com/spf13/pflag/flag.go @@ -0,0 +1,1157 @@ +// 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/spf13/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() + + // SortFlags is used to indicate, if user wants to have sorted flags in + // help/usage messages. + SortFlags bool + + 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 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 + f.sortedFormal = f.sortedFormal[:0] + for fname, flag := range f.formal { + nname := f.normalizeFlagName(flag.Name) + if fname == nname { + continue + } + flag.Name = string(nname) + delete(f.formal, fname) + f.formal[nname] = flag + if _, set := f.actual[fname]; set { + delete(f.actual, fname) + f.actual[nname] = flag + } + } +} + +// 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 or +// in primordial order if f.SortFlags is false, calling fn for each. +// It visits all flags, even those not set. +func (f *FlagSet) VisitAll(fn func(*Flag)) { + if len(f.formal) == 0 { + return + } + + var flags []*Flag + if f.SortFlags { + if len(f.formal) != len(f.sortedFormal) { + f.sortedFormal = sortFlags(f.formal) + } + flags = f.sortedFormal + } else { + flags = f.orderedFormal + } + + for _, flag := range flags { + 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 or +// in primordial order if f.SortFlags is false, 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 or +// in primordial order if f.SortFlags is false, calling fn for each. +// It visits only those flags that have been set. +func (f *FlagSet) Visit(fn func(*Flag)) { + if len(f.actual) == 0 { + return + } + + var flags []*Flag + if f.SortFlags { + if len(f.actual) != len(f.sortedActual) { + f.sortedActual = sortFlags(f.actual) + } + flags = f.sortedActual + } else { + flags = f.orderedActual + } + + for _, flag := range flags { + fn(flag) + } +} + +// Visit visits the command-line flags in lexicographical order or +// in primordial order if f.SortFlags is false, 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)) +} + +// ShorthandLookup returns the Flag structure of the short handed flag, +// returning nil if none exists. +// It panics, if len(name) > 1. +func (f *FlagSet) ShorthandLookup(name string) *Flag { + if name == "" { + return nil + } + if len(name) > 1 { + msg := fmt.Sprintf("can not look up shorthand which is more than one ASCII character: %q", name) + fmt.Fprintf(f.out(), msg) + panic(msg) + } + c := name[0] + return f.shorthands[c] +} + +// 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 usageMessage == "" { + 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 usageMessage == "" { + 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) +} + +// ShorthandLookup returns the Flag structure of the short handed flag, +// returning nil if none exists. +func ShorthandLookup(name string) *Flag { + return CommandLine.ShorthandLookup(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 { + var flagName string + if flag.Shorthand != "" && flag.ShorthandDeprecated == "" { + flagName = fmt.Sprintf("-%s, --%s", flag.Shorthand, flag.Name) + } else { + flagName = fmt.Sprintf("--%s", flag.Name) + } + return fmt.Errorf("invalid argument %q for %q flag: %v", value, flagName, err) + } + + if !flag.Changed { + if f.actual == nil { + f.actual = make(map[NormalizedName]*Flag) + } + f.actual[normalName] = flag + f.orderedActual = append(f.orderedActual, flag) + + flag.Changed = true + } + + if flag.Deprecated != "" { + fmt.Fprintf(f.out(), "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.Fprint(f.out(), usages) +} + +// defaultIsZeroValue returns true if the default value for this flag represents +// a zero value. +func (f *Flag) defaultIsZeroValue() bool { + switch f.Value.(type) { + case boolFlag: + return f.DefValue == "false" + case *durationValue: + // Beginning in Go 1.7, duration zero values are "0s" + return f.DefValue == "0" || f.DefValue == "0s" + case *intValue, *int8Value, *int32Value, *int64Value, *uintValue, *uint8Value, *uint16Value, *uint32Value, *uint64Value, *countValue, *float32Value, *float64Value: + return f.DefValue == "0" + case *stringValue: + return f.DefValue == "" + case *ipValue, *ipMaskValue, *ipNetValue: + return f.DefValue == "<nil>" + case *intSliceValue, *stringSliceValue, *stringArrayValue: + return f.DefValue == "[]" + default: + switch f.Value.String() { + 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. + } + } + + name = flag.Value.Type() + switch name { + case "bool": + name = "" + case "float64": + name = "float" + case "int64": + name = "int" + case "uint64": + name = "uint" + case "stringSlice": + name = "strings" + case "intSlice": + name = "ints" + case "uintSlice": + name = "uints" + case "boolSlice": + name = "bools" + } + + return +} + +// Splits the string `s` on whitespace into an initial substring up to +// `i` runes in length and the remainder. Will go `slop` over `i` if +// that encompasses the entire string (which allows the caller to +// avoid short orphan words on the final line). +func wrapN(i, slop int, s string) (string, string) { + if i+slop > len(s) { + return s, "" + } + + w := strings.LastIndexAny(s[:i], " \t") + if w <= 0 { + return s, "" + } + + return s[:w], s[w+1:] +} + +// Wraps the string `s` to a maximum width `w` with leading indent +// `i`. The first line is not indented (this is assumed to be done by +// caller). Pass `w` == 0 to do no wrapping +func wrap(i, w int, s string) string { + if w == 0 { + return s + } + + // space between indent i and end of line width w into which + // we should wrap the text. + wrap := w - i + + var r, l string + + // Not enough space for sensible wrapping. Wrap as a block on + // the next line instead. + if wrap < 24 { + i = 16 + wrap = w - i + r += "\n" + strings.Repeat(" ", i) + } + // If still not enough space then don't even try to wrap. + if wrap < 24 { + return s + } + + // Try to avoid short orphan words on the final line, by + // allowing wrapN to go a bit over if that would fit in the + // remainder of the line. + slop := 5 + wrap = wrap - slop + + // Handle first line, which is indented by the caller (or the + // special case above) + l, s = wrapN(wrap, slop, s) + r = r + l + + // Now wrap the rest + for s != "" { + var t string + + t, s = wrapN(wrap, slop, s) + r = r + "\n" + strings.Repeat(" ", i) + t + } + + return r + +} + +// FlagUsagesWrapped returns a string containing the usage information +// for all flags in the FlagSet. Wrapped to `cols` columns (0 for no +// wrapping) +func (f *FlagSet) FlagUsagesWrapped(cols int) string { + buf := new(bytes.Buffer) + + lines := make([]string, 0, len(f.formal)) + + maxlen := 0 + f.VisitAll(func(flag *Flag) { + if flag.Deprecated != "" || flag.Hidden { + return + } + + line := "" + if flag.Shorthand != "" && flag.ShorthandDeprecated == "" { + line = fmt.Sprintf(" -%s, --%s", flag.Shorthand, flag.Name) + } else { + line = fmt.Sprintf(" --%s", flag.Name) + } + + varname, usage := UnquoteUsage(flag) + if varname != "" { + line += " " + varname + } + if flag.NoOptDefVal != "" { + switch flag.Value.Type() { + case "string": + line += fmt.Sprintf("[=\"%s\"]", flag.NoOptDefVal) + case "bool": + if flag.NoOptDefVal != "true" { + line += fmt.Sprintf("[=%s]", flag.NoOptDefVal) + } + case "count": + if flag.NoOptDefVal != "+1" { + 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 !flag.defaultIsZeroValue() { + 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) + // maxlen + 2 comes from + 1 for the \x00 and + 1 for the (deliberate) off-by-one in maxlen-sidx + fmt.Fprintln(buf, line[:sidx], spacing, wrap(maxlen+2, cols, line[sidx+1:])) + } + + return buf.String() +} + +// FlagUsages returns a string containing the usage information for all flags in +// the FlagSet +func (f *FlagSet) FlagUsages() string { + return f.FlagUsagesWrapped(0) +} + +// 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) { + 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 + f.orderedFormal = append(f.orderedFormal, flag) + + if flag.Shorthand == "" { + return + } + if len(flag.Shorthand) > 1 { + msg := fmt.Sprintf("%q shorthand is more than one ASCII character", flag.Shorthand) + fmt.Fprintf(f.out(), msg) + panic(msg) + } + if f.shorthands == nil { + f.shorthands = make(map[byte]*Flag) + } + c := flag.Shorthand[0] + used, alreadyThere := f.shorthands[c] + if alreadyThere { + msg := fmt.Sprintf("unable to redefine %q shorthand in %q flagset: it's already used for %q flag", c, f.name, used.Name) + fmt.Fprintf(f.out(), msg) + panic(msg) + } + 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...) + if f.errorHandling != ContinueOnError { + 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) parseLongArg(s string, args []string, fn parseFunc) (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, exists := f.formal[f.normalizeFlagName(name)] + if !exists { + 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 flag.NoOptDefVal != "" { + // '--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 = fn(flag, value) + if err != nil { + f.failf(err.Error()) + } + return +} + +func (f *FlagSet) parseSingleShortArg(shorthands string, args []string, fn parseFunc) (outShorts string, outArgs []string, err error) { + if strings.HasPrefix(shorthands, "test.") { + return + } + + outArgs = args + outShorts = shorthands[1:] + c := shorthands[0] + + flag, exists := f.shorthands[c] + if !exists { + if c == 'h' { // special case for nice help message. + f.usage() + err = ErrHelp + return + } + err = f.failf("unknown shorthand flag: %q in -%s", c, shorthands) + return + } + + var value string + if len(shorthands) > 2 && shorthands[1] == '=' { + // '-f=arg' + value = shorthands[2:] + outShorts = "" + } else if flag.NoOptDefVal != "" { + // '-f' (arg was optional) + value = flag.NoOptDefVal + } else if len(shorthands) > 1 { + // '-farg' + value = shorthands[1:] + outShorts = "" + } else if len(args) > 0 { + // '-f arg' + value = args[0] + outArgs = args[1:] + } else { + // '-f' (arg was required) + err = f.failf("flag needs an argument: %q in -%s", c, shorthands) + return + } + + if flag.ShorthandDeprecated != "" { + fmt.Fprintf(f.out(), "Flag shorthand -%s has been deprecated, %s\n", flag.Shorthand, flag.ShorthandDeprecated) + } + + err = fn(flag, value) + if err != nil { + f.failf(err.Error()) + } + return +} + +func (f *FlagSet) parseShortArg(s string, args []string, fn parseFunc) (a []string, err error) { + a = args + shorthands := s[1:] + + // "shorthands" can be a series of shorthand letters of flags (e.g. "-vvv"). + for len(shorthands) > 0 { + shorthands, a, err = f.parseSingleShortArg(shorthands, args, fn) + if err != nil { + return + } + } + + return +} + +func (f *FlagSet) parseArgs(args []string, fn parseFunc) (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, fn) + } else { + args, err = f.parseShortArg(s, args, fn) + } + 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 + + if len(arguments) < 0 { + return nil + } + + f.args = make([]string, 0, len(arguments)) + + set := func(flag *Flag, value string) error { + return f.Set(flag.Name, value) + } + + err := f.parseArgs(arguments, set) + if err != nil { + switch f.errorHandling { + case ContinueOnError: + return err + case ExitOnError: + fmt.Println(err) + os.Exit(2) + case PanicOnError: + panic(err) + } + } + return nil +} + +type parseFunc func(flag *Flag, value string) error + +// ParseAll parses flag definitions from the argument list, which should not +// include the command name. The arguments for fn are flag and value. 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) ParseAll(arguments []string, fn func(flag *Flag, value string) error) error { + f.parsed = true + f.args = make([]string, 0, len(arguments)) + + err := f.parseArgs(arguments, fn) + 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:]) +} + +// ParseAll parses the command-line flags from os.Args[1:] and called fn for each. +// The arguments for fn are flag and value. Must be called after all flags are +// defined and before flags are accessed by the program. +func ParseAll(fn func(flag *Flag, value string) error) { + // Ignore errors; CommandLine is set for ExitOnError. + CommandLine.ParseAll(os.Args[1:], fn) +} + +// 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, +// error handling property and SortFlags set to true. +func NewFlagSet(name string, errorHandling ErrorHandling) *FlagSet { + f := &FlagSet{ + name: name, + errorHandling: errorHandling, + argsLenAtDash: -1, + interspersed: true, + SortFlags: 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 +} |