README

Description

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. For a more precise description, see the "Command-line flag syntax" section below.

pflag is available under the same style of BSD license as the Go language, which can be found in the LICENSE file.

Installation

pflag is available using the standard go get command.

Install by running:

go get github.com/ogier/pflag

Run tests by running:

go test github.com/ogier/pflag

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 *int = 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.

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.

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.

More info

You can see the full reference documentation of the pflag package at godoc.org, or through go's standard documentation system by running godoc -http=:6060 and browsing to http://localhost:6060/pkg/github.com/ogier/pflag after installation.

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Documentation

Overview

    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.

    Example
    Output:
    
    

    Index

    Examples

    Constants

    This section is empty.

    Variables

    View Source
    var CommandLine = NewFlagSet(os.Args[0], ExitOnError)

      The default set of command-line flags, parsed from os.Args.

      View Source
      var ErrHelp = errors.New("pflag: help requested")

        ErrHelp is the error returned if the flag -help is invoked but no such flag is defined.

        View Source
        var Usage = func() {
        	fmt.Fprintf(os.Stderr, "Usage of %s:\n", os.Args[0])
        	PrintDefaults()
        }

          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.

          Functions

          func Arg

          func Arg(i int) string

            Arg returns the i'th command-line argument. Arg(0) is the first remaining argument after flags have been processed.

            func Args

            func Args() []string

              Args returns the non-flag command-line arguments.

              func Bool

              func Bool(name string, value bool, usage string) *bool

                Bool defines a bool flag with specified name, default value, and usage string. The return value is the address of a bool variable that stores the value of the flag.

                func BoolP

                func BoolP(name, shorthand string, value bool, usage string) *bool

                  Like Bool, but accepts a shorthand letter that can be used after a single dash.

                  func BoolVar

                  func BoolVar(p *bool, name string, value bool, usage string)

                    BoolVar defines a bool flag with specified name, default value, and usage string. The argument p points to a bool variable in which to store the value of the flag.

                    func BoolVarP

                    func BoolVarP(p *bool, name, shorthand string, value bool, usage string)

                      Like BoolVar, but accepts a shorthand letter that can be used after a single dash.

                      func Duration

                      func Duration(name string, value time.Duration, usage string) *time.Duration

                        Duration defines a time.Duration flag with specified name, default value, and usage string. The return value is the address of a time.Duration variable that stores the value of the flag.

                        func DurationP

                        func DurationP(name, shorthand string, value time.Duration, usage string) *time.Duration

                          Like Duration, but accepts a shorthand letter that can be used after a single dash.

                          func DurationVar

                          func DurationVar(p *time.Duration, name string, value time.Duration, usage string)

                            DurationVar defines a time.Duration flag with specified name, default value, and usage string. The argument p points to a time.Duration variable in which to store the value of the flag.

                            func DurationVarP

                            func DurationVarP(p *time.Duration, name, shorthand string, value time.Duration, usage string)

                              Like DurationVar, but accepts a shorthand letter that can be used after a single dash.

                              func Float32

                              func Float32(name string, value float32, usage string) *float32

                                Float32 defines a float32 flag with specified name, default value, and usage string. The return value is the address of a float32 variable that stores the value of the flag.

                                func Float32P

                                func Float32P(name, shorthand string, value float32, usage string) *float32

                                  Like Float32, but accepts a shorthand letter that can be used after a single dash.

                                  func Float32Var

                                  func Float32Var(p *float32, name string, value float32, usage string)

                                    Float32Var defines a float32 flag with specified name, default value, and usage string. The argument p points to a float32 variable in which to store the value of the flag.

                                    func Float32VarP

                                    func Float32VarP(p *float32, name, shorthand string, value float32, usage string)

                                      Like Float32Var, but accepts a shorthand letter that can be used after a single dash.

                                      func Float64

                                      func Float64(name string, value float64, usage string) *float64

                                        Float64 defines a float64 flag with specified name, default value, and usage string. The return value is the address of a float64 variable that stores the value of the flag.

                                        func Float64P

                                        func Float64P(name, shorthand string, value float64, usage string) *float64

                                          Like Float64, but accepts a shorthand letter that can be used after a single dash.

                                          func Float64Var

                                          func Float64Var(p *float64, name string, value float64, usage string)

                                            Float64Var defines a float64 flag with specified name, default value, and usage string. The argument p points to a float64 variable in which to store the value of the flag.

                                            func Float64VarP

                                            func Float64VarP(p *float64, name, shorthand string, value float64, usage string)

                                              Like Float64Var, but accepts a shorthand letter that can be used after a single dash.

                                              func IP

                                              func IP(name string, value net.IP, usage string) *net.IP

                                                IP defines an net.IP flag with specified name, default value, and usage string. The return value is the address of an net.IP variable that stores the value of the flag.

                                                func IPMask

                                                func IPMask(name string, value net.IPMask, usage string) *net.IPMask

                                                  IPMask defines an net.IPMask flag with specified name, default value, and usage string. The return value is the address of an net.IPMask variable that stores the value of the flag.

                                                  func IPMaskP

                                                  func IPMaskP(name, shorthand string, value net.IPMask, usage string) *net.IPMask

                                                    Like IP, but accepts a shorthand letter that can be used after a single dash.

                                                    func IPMaskVar

                                                    func IPMaskVar(p *net.IPMask, name string, value net.IPMask, usage string)

                                                      IPMaskVar defines an net.IPMask flag with specified name, default value, and usage string. The argument p points to an net.IPMask variable in which to store the value of the flag.

                                                      func IPMaskVarP

                                                      func IPMaskVarP(p *net.IPMask, name, shorthand string, value net.IPMask, usage string)

                                                        Like IPMaskVar, but accepts a shorthand letter that can be used after a single dash.

                                                        func IPP

                                                        func IPP(name, shorthand string, value net.IP, usage string) *net.IP

                                                          Like IP, but accepts a shorthand letter that can be used after a single dash.

                                                          func IPVar

                                                          func IPVar(p *net.IP, name string, value net.IP, usage string)

                                                            IPVar defines an net.IP flag with specified name, default value, and usage string. The argument p points to an net.IP variable in which to store the value of the flag.

                                                            func IPVarP

                                                            func IPVarP(p *net.IP, name, shorthand string, value net.IP, usage string)

                                                              Like IPVar, but accepts a shorthand letter that can be used after a single dash.

                                                              func Int

                                                              func Int(name string, value int, usage string) *int

                                                                Int defines an int flag with specified name, default value, and usage string. The return value is the address of an int variable that stores the value of the flag.

                                                                func Int32

                                                                func Int32(name string, value int32, usage string) *int32

                                                                  Int32 defines an int32 flag with specified name, default value, and usage string. The return value is the address of an int32 variable that stores the value of the flag.

                                                                  func Int32P

                                                                  func Int32P(name, shorthand string, value int32, usage string) *int32

                                                                    Like Int32, but accepts a shorthand letter that can be used after a single dash.

                                                                    func Int32Var

                                                                    func Int32Var(p *int32, name string, value int32, usage string)

                                                                      Int32Var defines an int32 flag with specified name, default value, and usage string. The argument p points to an int32 variable in which to store the value of the flag.

                                                                      func Int32VarP

                                                                      func Int32VarP(p *int32, name, shorthand string, value int32, usage string)

                                                                        Like Int32Var, but accepts a shorthand letter that can be used after a single dash.

                                                                        func Int64

                                                                        func Int64(name string, value int64, usage string) *int64

                                                                          Int64 defines an int64 flag with specified name, default value, and usage string. The return value is the address of an int64 variable that stores the value of the flag.

                                                                          func Int64P

                                                                          func Int64P(name, shorthand string, value int64, usage string) *int64

                                                                            Like Int64, but accepts a shorthand letter that can be used after a single dash.

                                                                            func Int64Var

                                                                            func Int64Var(p *int64, name string, value int64, usage string)

                                                                              Int64Var defines an int64 flag with specified name, default value, and usage string. The argument p points to an int64 variable in which to store the value of the flag.

                                                                              func Int64VarP

                                                                              func Int64VarP(p *int64, name, shorthand string, value int64, usage string)

                                                                                Like Int64Var, but accepts a shorthand letter that can be used after a single dash.

                                                                                func Int8

                                                                                func Int8(name string, value int8, usage string) *int8

                                                                                  Int8 defines an int8 flag with specified name, default value, and usage string. The return value is the address of an int8 variable that stores the value of the flag.

                                                                                  func Int8P

                                                                                  func Int8P(name, shorthand string, value int8, usage string) *int8

                                                                                    Like Int8, but accepts a shorthand letter that can be used after a single dash.

                                                                                    func Int8Var

                                                                                    func Int8Var(p *int8, name string, value int8, usage string)

                                                                                      Int8Var defines an int8 flag with specified name, default value, and usage string. The argument p points to an int8 variable in which to store the value of the flag.

                                                                                      func Int8VarP

                                                                                      func Int8VarP(p *int8, name, shorthand string, value int8, usage string)

                                                                                        Like Int8Var, but accepts a shorthand letter that can be used after a single dash.

                                                                                        func IntP

                                                                                        func IntP(name, shorthand string, value int, usage string) *int

                                                                                          Like Int, but accepts a shorthand letter that can be used after a single dash.

                                                                                          func IntVar

                                                                                          func IntVar(p *int, name string, value int, usage string)

                                                                                            IntVar defines an int flag with specified name, default value, and usage string. The argument p points to an int variable in which to store the value of the flag.

                                                                                            func IntVarP

                                                                                            func IntVarP(p *int, name, shorthand string, value int, usage string)

                                                                                              Like IntVar, but accepts a shorthand letter that can be used after a single dash.

                                                                                              func NArg

                                                                                              func NArg() int

                                                                                                NArg is the number of arguments remaining after flags have been processed.

                                                                                                func NFlag

                                                                                                func NFlag() int

                                                                                                  NFlag returns the number of command-line flags that have been set.

                                                                                                  func Parse

                                                                                                  func Parse()

                                                                                                    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 ParseIPv4Mask

                                                                                                    func ParseIPv4Mask(s string) net.IPMask

                                                                                                      Parse IPv4 netmask written in IP form (e.g. 255.255.255.0). This function should really belong to the net package.

                                                                                                      func Parsed

                                                                                                      func Parsed() bool

                                                                                                        Parsed returns true if the command-line flags have been parsed.

                                                                                                        func PrintDefaults

                                                                                                        func PrintDefaults()

                                                                                                          PrintDefaults prints to standard error the default values of all defined command-line flags.

                                                                                                          func Set

                                                                                                          func Set(name, value string) error

                                                                                                            Set sets the value of the named command-line flag.

                                                                                                            func SetInterspersed

                                                                                                            func SetInterspersed(interspersed bool)

                                                                                                              Whether to support interspersed option/non-option arguments.

                                                                                                              func String

                                                                                                              func String(name string, value string, usage string) *string

                                                                                                                String defines a string flag with specified name, default value, and usage string. The return value is the address of a string variable that stores the value of the flag.

                                                                                                                func StringP

                                                                                                                func StringP(name, shorthand string, value string, usage string) *string

                                                                                                                  Like String, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                  func StringVar

                                                                                                                  func StringVar(p *string, name string, value string, usage string)

                                                                                                                    StringVar defines a string flag with specified name, default value, and usage string. The argument p points to a string variable in which to store the value of the flag.

                                                                                                                    func StringVarP

                                                                                                                    func StringVarP(p *string, name, shorthand string, value string, usage string)

                                                                                                                      Like StringVar, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                      func Uint

                                                                                                                      func Uint(name string, value uint, usage string) *uint

                                                                                                                        Uint defines a uint flag with specified name, default value, and usage string. The return value is the address of a uint variable that stores the value of the flag.

                                                                                                                        func Uint16

                                                                                                                        func Uint16(name string, value uint16, usage string) *uint16

                                                                                                                          Uint16 defines a uint flag with specified name, default value, and usage string. The return value is the address of a uint variable that stores the value of the flag.

                                                                                                                          func Uint16P

                                                                                                                          func Uint16P(name, shorthand string, value uint16, usage string) *uint16

                                                                                                                            Like Uint16, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                            func Uint16Var

                                                                                                                            func Uint16Var(p *uint16, name string, value uint16, usage string)

                                                                                                                              Uint16Var defines a uint flag with specified name, default value, and usage string. The argument p points to a uint variable in which to store the value of the flag.

                                                                                                                              func Uint16VarP

                                                                                                                              func Uint16VarP(p *uint16, name, shorthand string, value uint16, usage string)

                                                                                                                                Like Uint16Var, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                func Uint32

                                                                                                                                func Uint32(name string, value uint32, usage string) *uint32

                                                                                                                                  Uint32 defines a uint32 flag with specified name, default value, and usage string. The return value is the address of a uint32 variable that stores the value of the flag.

                                                                                                                                  func Uint32P

                                                                                                                                  func Uint32P(name, shorthand string, value uint32, usage string) *uint32

                                                                                                                                    Like Uint32, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                    func Uint32Var

                                                                                                                                    func Uint32Var(p *uint32, name string, value uint32, usage string)

                                                                                                                                      Uint32Var defines a uint32 flag with specified name, default value, and usage string. The argument p points to a uint32 variable in which to store the value of the flag.

                                                                                                                                      func Uint32VarP

                                                                                                                                      func Uint32VarP(p *uint32, name, shorthand string, value uint32, usage string)

                                                                                                                                        Like Uint32Var, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                        func Uint64

                                                                                                                                        func Uint64(name string, value uint64, usage string) *uint64

                                                                                                                                          Uint64 defines a uint64 flag with specified name, default value, and usage string. The return value is the address of a uint64 variable that stores the value of the flag.

                                                                                                                                          func Uint64P

                                                                                                                                          func Uint64P(name, shorthand string, value uint64, usage string) *uint64

                                                                                                                                            Like Uint64, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                            func Uint64Var

                                                                                                                                            func Uint64Var(p *uint64, name string, value uint64, usage string)

                                                                                                                                              Uint64Var defines a uint64 flag with specified name, default value, and usage string. The argument p points to a uint64 variable in which to store the value of the flag.

                                                                                                                                              func Uint64VarP

                                                                                                                                              func Uint64VarP(p *uint64, name, shorthand string, value uint64, usage string)

                                                                                                                                                Like Uint64Var, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                func Uint8

                                                                                                                                                func Uint8(name string, value uint8, usage string) *uint8

                                                                                                                                                  Uint8 defines a uint8 flag with specified name, default value, and usage string. The return value is the address of a uint8 variable that stores the value of the flag.

                                                                                                                                                  func Uint8P

                                                                                                                                                  func Uint8P(name, shorthand string, value uint8, usage string) *uint8

                                                                                                                                                    Like Uint8, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                    func Uint8Var

                                                                                                                                                    func Uint8Var(p *uint8, name string, value uint8, usage string)

                                                                                                                                                      Uint8Var defines a uint8 flag with specified name, default value, and usage string. The argument p points to a uint8 variable in which to store the value of the flag.

                                                                                                                                                      func Uint8VarP

                                                                                                                                                      func Uint8VarP(p *uint8, name, shorthand string, value uint8, usage string)

                                                                                                                                                        Like Uint8Var, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                        func UintP

                                                                                                                                                        func UintP(name, shorthand string, value uint, usage string) *uint

                                                                                                                                                          Like Uint, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                          func UintVar

                                                                                                                                                          func UintVar(p *uint, name string, value uint, usage string)

                                                                                                                                                            UintVar defines a uint flag with specified name, default value, and usage string. The argument p points to a uint variable in which to store the value of the flag.

                                                                                                                                                            func UintVarP

                                                                                                                                                            func UintVarP(p *uint, name, shorthand string, value uint, usage string)

                                                                                                                                                              Like UintVar, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                              func Var

                                                                                                                                                              func Var(value Value, name string, usage string)

                                                                                                                                                                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 VarP

                                                                                                                                                                func VarP(value Value, name, shorthand, usage string)

                                                                                                                                                                  Like Var, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                  func Visit

                                                                                                                                                                  func Visit(fn func(*Flag))

                                                                                                                                                                    Visit visits the command-line flags in lexicographical order, calling fn for each. It visits only those flags that have been set.

                                                                                                                                                                    func VisitAll

                                                                                                                                                                    func VisitAll(fn func(*Flag))

                                                                                                                                                                      VisitAll visits the command-line flags in lexicographical order, calling fn for each. It visits all flags, even those not set.

                                                                                                                                                                      Types

                                                                                                                                                                      type ErrorHandling

                                                                                                                                                                      type ErrorHandling int

                                                                                                                                                                        ErrorHandling defines how to handle flag parsing errors.

                                                                                                                                                                        const (
                                                                                                                                                                        	ContinueOnError ErrorHandling = iota
                                                                                                                                                                        	ExitOnError
                                                                                                                                                                        	PanicOnError
                                                                                                                                                                        )

                                                                                                                                                                        type 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
                                                                                                                                                                        }

                                                                                                                                                                          A Flag represents the state of a flag.

                                                                                                                                                                          func Lookup

                                                                                                                                                                          func Lookup(name string) *Flag

                                                                                                                                                                            Lookup returns the Flag structure of the named command-line flag, returning nil if none exists.

                                                                                                                                                                            type FlagSet

                                                                                                                                                                            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()
                                                                                                                                                                            	// contains filtered or unexported fields
                                                                                                                                                                            }

                                                                                                                                                                              A FlagSet represents a set of defined flags.

                                                                                                                                                                              func NewFlagSet

                                                                                                                                                                              func NewFlagSet(name string, errorHandling ErrorHandling) *FlagSet

                                                                                                                                                                                NewFlagSet returns a new, empty flag set with the specified name and error handling property.

                                                                                                                                                                                func (*FlagSet) Arg

                                                                                                                                                                                func (f *FlagSet) Arg(i int) string

                                                                                                                                                                                  Arg returns the i'th argument. Arg(0) is the first remaining argument after flags have been processed.

                                                                                                                                                                                  func (*FlagSet) Args

                                                                                                                                                                                  func (f *FlagSet) Args() []string

                                                                                                                                                                                    Args returns the non-flag arguments.

                                                                                                                                                                                    func (*FlagSet) Bool

                                                                                                                                                                                    func (f *FlagSet) Bool(name string, value bool, usage string) *bool

                                                                                                                                                                                      Bool defines a bool flag with specified name, default value, and usage string. The return value is the address of a bool variable that stores the value of the flag.

                                                                                                                                                                                      func (*FlagSet) BoolP

                                                                                                                                                                                      func (f *FlagSet) BoolP(name, shorthand string, value bool, usage string) *bool

                                                                                                                                                                                        Like Bool, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                        func (*FlagSet) BoolVar

                                                                                                                                                                                        func (f *FlagSet) BoolVar(p *bool, name string, value bool, usage string)

                                                                                                                                                                                          BoolVar defines a bool flag with specified name, default value, and usage string. The argument p points to a bool variable in which to store the value of the flag.

                                                                                                                                                                                          func (*FlagSet) BoolVarP

                                                                                                                                                                                          func (f *FlagSet) BoolVarP(p *bool, name, shorthand string, value bool, usage string)

                                                                                                                                                                                            Like BoolVar, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                            func (*FlagSet) Duration

                                                                                                                                                                                            func (f *FlagSet) Duration(name string, value time.Duration, usage string) *time.Duration

                                                                                                                                                                                              Duration defines a time.Duration flag with specified name, default value, and usage string. The return value is the address of a time.Duration variable that stores the value of the flag.

                                                                                                                                                                                              func (*FlagSet) DurationP

                                                                                                                                                                                              func (f *FlagSet) DurationP(name, shorthand string, value time.Duration, usage string) *time.Duration

                                                                                                                                                                                                Like Duration, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                func (*FlagSet) DurationVar

                                                                                                                                                                                                func (f *FlagSet) DurationVar(p *time.Duration, name string, value time.Duration, usage string)

                                                                                                                                                                                                  DurationVar defines a time.Duration flag with specified name, default value, and usage string. The argument p points to a time.Duration variable in which to store the value of the flag.

                                                                                                                                                                                                  func (*FlagSet) DurationVarP

                                                                                                                                                                                                  func (f *FlagSet) DurationVarP(p *time.Duration, name, shorthand string, value time.Duration, usage string)

                                                                                                                                                                                                    Like DurationVar, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                    func (*FlagSet) Float32

                                                                                                                                                                                                    func (f *FlagSet) Float32(name string, value float32, usage string) *float32

                                                                                                                                                                                                      Float32 defines a float32 flag with specified name, default value, and usage string. The return value is the address of a float32 variable that stores the value of the flag.

                                                                                                                                                                                                      func (*FlagSet) Float32P

                                                                                                                                                                                                      func (f *FlagSet) Float32P(name, shorthand string, value float32, usage string) *float32

                                                                                                                                                                                                        Like Float32, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                        func (*FlagSet) Float32Var

                                                                                                                                                                                                        func (f *FlagSet) Float32Var(p *float32, name string, value float32, usage string)

                                                                                                                                                                                                          Float32Var defines a float32 flag with specified name, default value, and usage string. The argument p points to a float32 variable in which to store the value of the flag.

                                                                                                                                                                                                          func (*FlagSet) Float32VarP

                                                                                                                                                                                                          func (f *FlagSet) Float32VarP(p *float32, name, shorthand string, value float32, usage string)

                                                                                                                                                                                                            Like Float32Var, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                            func (*FlagSet) Float64

                                                                                                                                                                                                            func (f *FlagSet) Float64(name string, value float64, usage string) *float64

                                                                                                                                                                                                              Float64 defines a float64 flag with specified name, default value, and usage string. The return value is the address of a float64 variable that stores the value of the flag.

                                                                                                                                                                                                              func (*FlagSet) Float64P

                                                                                                                                                                                                              func (f *FlagSet) Float64P(name, shorthand string, value float64, usage string) *float64

                                                                                                                                                                                                                Like Float64, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                func (*FlagSet) Float64Var

                                                                                                                                                                                                                func (f *FlagSet) Float64Var(p *float64, name string, value float64, usage string)

                                                                                                                                                                                                                  Float64Var defines a float64 flag with specified name, default value, and usage string. The argument p points to a float64 variable in which to store the value of the flag.

                                                                                                                                                                                                                  func (*FlagSet) Float64VarP

                                                                                                                                                                                                                  func (f *FlagSet) Float64VarP(p *float64, name, shorthand string, value float64, usage string)

                                                                                                                                                                                                                    Like Float64Var, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                    func (*FlagSet) IP

                                                                                                                                                                                                                    func (f *FlagSet) IP(name string, value net.IP, usage string) *net.IP

                                                                                                                                                                                                                      IP defines an net.IP flag with specified name, default value, and usage string. The return value is the address of an net.IP variable that stores the value of the flag.

                                                                                                                                                                                                                      func (*FlagSet) IPMask

                                                                                                                                                                                                                      func (f *FlagSet) IPMask(name string, value net.IPMask, usage string) *net.IPMask

                                                                                                                                                                                                                        IPMask defines an net.IPMask flag with specified name, default value, and usage string. The return value is the address of an net.IPMask variable that stores the value of the flag.

                                                                                                                                                                                                                        func (*FlagSet) IPMaskP

                                                                                                                                                                                                                        func (f *FlagSet) IPMaskP(name, shorthand string, value net.IPMask, usage string) *net.IPMask

                                                                                                                                                                                                                          Like IPMask, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                          func (*FlagSet) IPMaskVar

                                                                                                                                                                                                                          func (f *FlagSet) IPMaskVar(p *net.IPMask, name string, value net.IPMask, usage string)

                                                                                                                                                                                                                            IPMaskVar defines an net.IPMask flag with specified name, default value, and usage string. The argument p points to an net.IPMask variable in which to store the value of the flag.

                                                                                                                                                                                                                            func (*FlagSet) IPMaskVarP

                                                                                                                                                                                                                            func (f *FlagSet) IPMaskVarP(p *net.IPMask, name, shorthand string, value net.IPMask, usage string)

                                                                                                                                                                                                                              Like IPMaskVar, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                              func (*FlagSet) IPP

                                                                                                                                                                                                                              func (f *FlagSet) IPP(name, shorthand string, value net.IP, usage string) *net.IP

                                                                                                                                                                                                                                Like IP, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                func (*FlagSet) IPVar

                                                                                                                                                                                                                                func (f *FlagSet) IPVar(p *net.IP, name string, value net.IP, usage string)

                                                                                                                                                                                                                                  IPVar defines an net.IP flag with specified name, default value, and usage string. The argument p points to an net.IP variable in which to store the value of the flag.

                                                                                                                                                                                                                                  func (*FlagSet) IPVarP

                                                                                                                                                                                                                                  func (f *FlagSet) IPVarP(p *net.IP, name, shorthand string, value net.IP, usage string)

                                                                                                                                                                                                                                    Like IPVar, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                    func (*FlagSet) Init

                                                                                                                                                                                                                                    func (f *FlagSet) Init(name string, errorHandling ErrorHandling)

                                                                                                                                                                                                                                      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 (*FlagSet) Int

                                                                                                                                                                                                                                      func (f *FlagSet) Int(name string, value int, usage string) *int

                                                                                                                                                                                                                                        Int defines an int flag with specified name, default value, and usage string. The return value is the address of an int variable that stores the value of the flag.

                                                                                                                                                                                                                                        func (*FlagSet) Int32

                                                                                                                                                                                                                                        func (f *FlagSet) Int32(name string, value int32, usage string) *int32

                                                                                                                                                                                                                                          Int32 defines an int32 flag with specified name, default value, and usage string. The return value is the address of an int32 variable that stores the value of the flag.

                                                                                                                                                                                                                                          func (*FlagSet) Int32P

                                                                                                                                                                                                                                          func (f *FlagSet) Int32P(name, shorthand string, value int32, usage string) *int32

                                                                                                                                                                                                                                            Like Int32, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                            func (*FlagSet) Int32Var

                                                                                                                                                                                                                                            func (f *FlagSet) Int32Var(p *int32, name string, value int32, usage string)

                                                                                                                                                                                                                                              Int32Var defines an int32 flag with specified name, default value, and usage string. The argument p points to an int32 variable in which to store the value of the flag.

                                                                                                                                                                                                                                              func (*FlagSet) Int32VarP

                                                                                                                                                                                                                                              func (f *FlagSet) Int32VarP(p *int32, name, shorthand string, value int32, usage string)

                                                                                                                                                                                                                                                Like Int32Var, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                func (*FlagSet) Int64

                                                                                                                                                                                                                                                func (f *FlagSet) Int64(name string, value int64, usage string) *int64

                                                                                                                                                                                                                                                  Int64 defines an int64 flag with specified name, default value, and usage string. The return value is the address of an int64 variable that stores the value of the flag.

                                                                                                                                                                                                                                                  func (*FlagSet) Int64P

                                                                                                                                                                                                                                                  func (f *FlagSet) Int64P(name, shorthand string, value int64, usage string) *int64

                                                                                                                                                                                                                                                    Like Int64, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                    func (*FlagSet) Int64Var

                                                                                                                                                                                                                                                    func (f *FlagSet) Int64Var(p *int64, name string, value int64, usage string)

                                                                                                                                                                                                                                                      Int64Var defines an int64 flag with specified name, default value, and usage string. The argument p points to an int64 variable in which to store the value of the flag.

                                                                                                                                                                                                                                                      func (*FlagSet) Int64VarP

                                                                                                                                                                                                                                                      func (f *FlagSet) Int64VarP(p *int64, name, shorthand string, value int64, usage string)

                                                                                                                                                                                                                                                        Like Int64Var, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                        func (*FlagSet) Int8

                                                                                                                                                                                                                                                        func (f *FlagSet) Int8(name string, value int8, usage string) *int8

                                                                                                                                                                                                                                                          Int8 defines an int8 flag with specified name, default value, and usage string. The return value is the address of an int8 variable that stores the value of the flag.

                                                                                                                                                                                                                                                          func (*FlagSet) Int8P

                                                                                                                                                                                                                                                          func (f *FlagSet) Int8P(name, shorthand string, value int8, usage string) *int8

                                                                                                                                                                                                                                                            Like Int8, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                            func (*FlagSet) Int8Var

                                                                                                                                                                                                                                                            func (f *FlagSet) Int8Var(p *int8, name string, value int8, usage string)

                                                                                                                                                                                                                                                              Int8Var defines an int8 flag with specified name, default value, and usage string. The argument p points to an int8 variable in which to store the value of the flag.

                                                                                                                                                                                                                                                              func (*FlagSet) Int8VarP

                                                                                                                                                                                                                                                              func (f *FlagSet) Int8VarP(p *int8, name, shorthand string, value int8, usage string)

                                                                                                                                                                                                                                                                Like Int8Var, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                                func (*FlagSet) IntP

                                                                                                                                                                                                                                                                func (f *FlagSet) IntP(name, shorthand string, value int, usage string) *int

                                                                                                                                                                                                                                                                  Like Int, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                                  func (*FlagSet) IntVar

                                                                                                                                                                                                                                                                  func (f *FlagSet) IntVar(p *int, name string, value int, usage string)

                                                                                                                                                                                                                                                                    IntVar defines an int flag with specified name, default value, and usage string. The argument p points to an int variable in which to store the value of the flag.

                                                                                                                                                                                                                                                                    func (*FlagSet) IntVarP

                                                                                                                                                                                                                                                                    func (f *FlagSet) IntVarP(p *int, name, shorthand string, value int, usage string)

                                                                                                                                                                                                                                                                      Like IntVar, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                                      func (*FlagSet) Lookup

                                                                                                                                                                                                                                                                      func (f *FlagSet) Lookup(name string) *Flag

                                                                                                                                                                                                                                                                        Lookup returns the Flag structure of the named flag, returning nil if none exists.

                                                                                                                                                                                                                                                                        func (*FlagSet) NArg

                                                                                                                                                                                                                                                                        func (f *FlagSet) NArg() int

                                                                                                                                                                                                                                                                          NArg is the number of arguments remaining after flags have been processed.

                                                                                                                                                                                                                                                                          func (*FlagSet) NFlag

                                                                                                                                                                                                                                                                          func (f *FlagSet) NFlag() int

                                                                                                                                                                                                                                                                            NFlag returns the number of flags that have been set.

                                                                                                                                                                                                                                                                            func (*FlagSet) Parse

                                                                                                                                                                                                                                                                            func (f *FlagSet) Parse(arguments []string) error

                                                                                                                                                                                                                                                                              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 (*FlagSet) Parsed

                                                                                                                                                                                                                                                                              func (f *FlagSet) Parsed() bool

                                                                                                                                                                                                                                                                                Parsed reports whether f.Parse has been called.

                                                                                                                                                                                                                                                                                func (*FlagSet) PrintDefaults

                                                                                                                                                                                                                                                                                func (f *FlagSet) PrintDefaults()

                                                                                                                                                                                                                                                                                  PrintDefaults prints, to standard error unless configured otherwise, the default values of all defined flags in the set.

                                                                                                                                                                                                                                                                                  func (*FlagSet) Set

                                                                                                                                                                                                                                                                                  func (f *FlagSet) Set(name, value string) error

                                                                                                                                                                                                                                                                                    Set sets the value of the named flag.

                                                                                                                                                                                                                                                                                    func (*FlagSet) SetInterspersed

                                                                                                                                                                                                                                                                                    func (f *FlagSet) SetInterspersed(interspersed bool)

                                                                                                                                                                                                                                                                                      Whether to support interspersed option/non-option arguments.

                                                                                                                                                                                                                                                                                      func (*FlagSet) SetOutput

                                                                                                                                                                                                                                                                                      func (f *FlagSet) SetOutput(output io.Writer)

                                                                                                                                                                                                                                                                                        SetOutput sets the destination for usage and error messages. If output is nil, os.Stderr is used.

                                                                                                                                                                                                                                                                                        func (*FlagSet) String

                                                                                                                                                                                                                                                                                        func (f *FlagSet) String(name string, value string, usage string) *string

                                                                                                                                                                                                                                                                                          String defines a string flag with specified name, default value, and usage string. The return value is the address of a string variable that stores the value of the flag.

                                                                                                                                                                                                                                                                                          func (*FlagSet) StringP

                                                                                                                                                                                                                                                                                          func (f *FlagSet) StringP(name, shorthand string, value string, usage string) *string

                                                                                                                                                                                                                                                                                            Like String, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                                                            func (*FlagSet) StringVar

                                                                                                                                                                                                                                                                                            func (f *FlagSet) StringVar(p *string, name string, value string, usage string)

                                                                                                                                                                                                                                                                                              StringVar defines a string flag with specified name, default value, and usage string. The argument p points to a string variable in which to store the value of the flag.

                                                                                                                                                                                                                                                                                              func (*FlagSet) StringVarP

                                                                                                                                                                                                                                                                                              func (f *FlagSet) StringVarP(p *string, name, shorthand string, value string, usage string)

                                                                                                                                                                                                                                                                                                Like StringVar, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                                                                func (*FlagSet) Uint

                                                                                                                                                                                                                                                                                                func (f *FlagSet) Uint(name string, value uint, usage string) *uint

                                                                                                                                                                                                                                                                                                  Uint defines a uint flag with specified name, default value, and usage string. The return value is the address of a uint variable that stores the value of the flag.

                                                                                                                                                                                                                                                                                                  func (*FlagSet) Uint16

                                                                                                                                                                                                                                                                                                  func (f *FlagSet) Uint16(name string, value uint16, usage string) *uint16

                                                                                                                                                                                                                                                                                                    Uint16 defines a uint flag with specified name, default value, and usage string. The return value is the address of a uint variable that stores the value of the flag.

                                                                                                                                                                                                                                                                                                    func (*FlagSet) Uint16P

                                                                                                                                                                                                                                                                                                    func (f *FlagSet) Uint16P(name, shorthand string, value uint16, usage string) *uint16

                                                                                                                                                                                                                                                                                                      Like Uint16, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                                                                      func (*FlagSet) Uint16Var

                                                                                                                                                                                                                                                                                                      func (f *FlagSet) Uint16Var(p *uint16, name string, value uint16, usage string)

                                                                                                                                                                                                                                                                                                        Uint16Var defines a uint flag with specified name, default value, and usage string. The argument p points to a uint variable in which to store the value of the flag.

                                                                                                                                                                                                                                                                                                        func (*FlagSet) Uint16VarP

                                                                                                                                                                                                                                                                                                        func (f *FlagSet) Uint16VarP(p *uint16, name, shorthand string, value uint16, usage string)

                                                                                                                                                                                                                                                                                                          Like Uint16Var, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                                                                          func (*FlagSet) Uint32

                                                                                                                                                                                                                                                                                                          func (f *FlagSet) Uint32(name string, value uint32, usage string) *uint32

                                                                                                                                                                                                                                                                                                            Uint32 defines a uint32 flag with specified name, default value, and usage string. The return value is the address of a uint32 variable that stores the value of the flag.

                                                                                                                                                                                                                                                                                                            func (*FlagSet) Uint32P

                                                                                                                                                                                                                                                                                                            func (f *FlagSet) Uint32P(name, shorthand string, value uint32, usage string) *uint32

                                                                                                                                                                                                                                                                                                              Like Uint32, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                                                                              func (*FlagSet) Uint32Var

                                                                                                                                                                                                                                                                                                              func (f *FlagSet) Uint32Var(p *uint32, name string, value uint32, usage string)

                                                                                                                                                                                                                                                                                                                Uint32Var defines a uint32 flag with specified name, default value, and usage string. The argument p points to a uint32 variable in which to store the value of the flag.

                                                                                                                                                                                                                                                                                                                func (*FlagSet) Uint32VarP

                                                                                                                                                                                                                                                                                                                func (f *FlagSet) Uint32VarP(p *uint32, name, shorthand string, value uint32, usage string)

                                                                                                                                                                                                                                                                                                                  Like Uint32Var, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                                                                                  func (*FlagSet) Uint64

                                                                                                                                                                                                                                                                                                                  func (f *FlagSet) Uint64(name string, value uint64, usage string) *uint64

                                                                                                                                                                                                                                                                                                                    Uint64 defines a uint64 flag with specified name, default value, and usage string. The return value is the address of a uint64 variable that stores the value of the flag.

                                                                                                                                                                                                                                                                                                                    func (*FlagSet) Uint64P

                                                                                                                                                                                                                                                                                                                    func (f *FlagSet) Uint64P(name, shorthand string, value uint64, usage string) *uint64

                                                                                                                                                                                                                                                                                                                      Like Uint64, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                                                                                      func (*FlagSet) Uint64Var

                                                                                                                                                                                                                                                                                                                      func (f *FlagSet) Uint64Var(p *uint64, name string, value uint64, usage string)

                                                                                                                                                                                                                                                                                                                        Uint64Var defines a uint64 flag with specified name, default value, and usage string. The argument p points to a uint64 variable in which to store the value of the flag.

                                                                                                                                                                                                                                                                                                                        func (*FlagSet) Uint64VarP

                                                                                                                                                                                                                                                                                                                        func (f *FlagSet) Uint64VarP(p *uint64, name, shorthand string, value uint64, usage string)

                                                                                                                                                                                                                                                                                                                          Like Uint64Var, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                                                                                          func (*FlagSet) Uint8

                                                                                                                                                                                                                                                                                                                          func (f *FlagSet) Uint8(name string, value uint8, usage string) *uint8

                                                                                                                                                                                                                                                                                                                            Uint8 defines a uint8 flag with specified name, default value, and usage string. The return value is the address of a uint8 variable that stores the value of the flag.

                                                                                                                                                                                                                                                                                                                            func (*FlagSet) Uint8P

                                                                                                                                                                                                                                                                                                                            func (f *FlagSet) Uint8P(name, shorthand string, value uint8, usage string) *uint8

                                                                                                                                                                                                                                                                                                                              Like Uint8, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                                                                                              func (*FlagSet) Uint8Var

                                                                                                                                                                                                                                                                                                                              func (f *FlagSet) Uint8Var(p *uint8, name string, value uint8, usage string)

                                                                                                                                                                                                                                                                                                                                Uint8Var defines a uint8 flag with specified name, default value, and usage string. The argument p points to a uint8 variable in which to store the value of the flag.

                                                                                                                                                                                                                                                                                                                                func (*FlagSet) Uint8VarP

                                                                                                                                                                                                                                                                                                                                func (f *FlagSet) Uint8VarP(p *uint8, name, shorthand string, value uint8, usage string)

                                                                                                                                                                                                                                                                                                                                  Like Uint8Var, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                                                                                                  func (*FlagSet) UintP

                                                                                                                                                                                                                                                                                                                                  func (f *FlagSet) UintP(name, shorthand string, value uint, usage string) *uint

                                                                                                                                                                                                                                                                                                                                    Like Uint, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                                                                                                    func (*FlagSet) UintVar

                                                                                                                                                                                                                                                                                                                                    func (f *FlagSet) UintVar(p *uint, name string, value uint, usage string)

                                                                                                                                                                                                                                                                                                                                      UintVar defines a uint flag with specified name, default value, and usage string. The argument p points to a uint variable in which to store the value of the flag.

                                                                                                                                                                                                                                                                                                                                      func (*FlagSet) UintVarP

                                                                                                                                                                                                                                                                                                                                      func (f *FlagSet) UintVarP(p *uint, name, shorthand string, value uint, usage string)

                                                                                                                                                                                                                                                                                                                                        Like UintVar, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                                                                                                        func (*FlagSet) Var

                                                                                                                                                                                                                                                                                                                                        func (f *FlagSet) Var(value Value, name string, usage string)

                                                                                                                                                                                                                                                                                                                                          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 (*FlagSet) VarP

                                                                                                                                                                                                                                                                                                                                          func (f *FlagSet) VarP(value Value, name, shorthand, usage string)

                                                                                                                                                                                                                                                                                                                                            Like Var, but accepts a shorthand letter that can be used after a single dash.

                                                                                                                                                                                                                                                                                                                                            func (*FlagSet) Visit

                                                                                                                                                                                                                                                                                                                                            func (f *FlagSet) Visit(fn func(*Flag))

                                                                                                                                                                                                                                                                                                                                              Visit visits the flags in lexicographical order, calling fn for each. It visits only those flags that have been set.

                                                                                                                                                                                                                                                                                                                                              func (*FlagSet) VisitAll

                                                                                                                                                                                                                                                                                                                                              func (f *FlagSet) VisitAll(fn func(*Flag))

                                                                                                                                                                                                                                                                                                                                                VisitAll visits the flags in lexicographical order, calling fn for each. It visits all flags, even those not set.

                                                                                                                                                                                                                                                                                                                                                type Value

                                                                                                                                                                                                                                                                                                                                                type Value interface {
                                                                                                                                                                                                                                                                                                                                                	String() string
                                                                                                                                                                                                                                                                                                                                                	Set(string) error
                                                                                                                                                                                                                                                                                                                                                }

                                                                                                                                                                                                                                                                                                                                                  Value is the interface to the dynamic value stored in a flag. (The default value is represented as a string.)