The highest tagged major version is
README
¶
cli
/
Notice: This is the library formerly known as
github.com/codegangsta/cli -- Github will automatically redirect requests
to this repository, but we recommend updating your references for clarity.
cli is a simple, fast, and fun package for building command line apps in Go. The goal is to enable developers to write fast and distributable command line applications in an expressive way.
- Overview
- Installation
- Getting Started
- Examples
- Contribution Guidelines
Overview
Command line apps are usually so tiny that there is absolutely no reason why your code should not be self-documenting. Things like generating help text and parsing command flags/options should not hinder productivity when writing a command line app.
This is where cli comes into play. cli makes command line programming fun, organized, and expressive!
Installation
Make sure you have a working Go environment. Go version 1.2+ is supported. See the install instructions for Go.
To install cli, simply run:
$ go get github.com/urfave/cli
Make sure your PATH includes the $GOPATH/bin directory so your commands can
be easily used:
export PATH=$PATH:$GOPATH/bin
Supported platforms
cli is tested against multiple versions of Go on Linux, and against the latest
released version of Go on OS X and Windows. For full details, see
./.travis.yml and ./appveyor.yml.
Using the v2 branch
Warning: The v2 branch is currently unreleased and considered unstable.
There is currently a long-lived branch named v2 that is intended to land as
the new master branch once development there has settled down. The current
master branch (mirrored as v1) is being manually merged into v2 on
an irregular human-based schedule, but generally if one wants to "upgrade" to
v2 now and accept the volatility (read: "awesomeness") that comes along with
that, please use whatever version pinning of your preference, such as via
gopkg.in:
$ go get gopkg.in/urfave/cli.v2
...
import (
"gopkg.in/urfave/cli.v2" // imports as package "cli"
)
...
NOTE: There is a migrator (python) script available to aid with the transition from the v1 to v2 API.
Pinning to the v1 releases
Similarly to the section above describing use of the v2 branch, if one wants
to avoid any unexpected compatibility pains once v2 becomes master, then
pinning to v1 is an acceptable option, e.g.:
$ go get gopkg.in/urfave/cli.v1
...
import (
"gopkg.in/urfave/cli.v1" // imports as package "cli"
)
...
This will pull the latest tagged v1 release (e.g. v1.18.1 at the time of writing).
Getting Started
One of the philosophies behind cli is that an API should be playful and full of
discovery. So a cli app can be as little as one line of code in main().
package main
import (
"os"
"gopkg.in/urfave/cli.v2"
)
func main() {
(&cli.App{}).Run(os.Args)
}
This app will run and show help text, but is not very useful. Let's give an action to execute and some help documentation:
package main
import (
"fmt"
"os"
"gopkg.in/urfave/cli.v2"
)
func main() {
app := &cli.App{
Name: "boom",
Usage: "make an explosive entrance",
Action: func(c *cli.Context) error {
fmt.Println("boom! I say!")
return nil
},
}
app.Run(os.Args)
}
Running this already gives you a ton of functionality, plus support for things like subcommands and flags, which are covered below.
Examples
Being a programmer can be a lonely job. Thankfully by the power of automation that is not the case! Let's create a greeter app to fend off our demons of loneliness!
Start by creating a directory named greet, and within it, add a file,
greet.go with the following code in it:
package main
import (
"fmt"
"os"
"gopkg.in/urfave/cli.v2"
)
func main() {
app := &cli.App{
Name: "greet",
Usage: "fight the loneliness!",
Action: func(c *cli.Context) error {
fmt.Println("Hello friend!")
return nil
},
}
app.Run(os.Args)
}
Install our command to the $GOPATH/bin directory:
$ go install
Finally run our new command:
$ greet
Hello friend!
cli also generates neat help text:
$ greet help
NAME:
greet - fight the loneliness!
USAGE:
greet [global options] command [command options] [arguments...]
VERSION:
0.0.0
COMMANDS:
help, h Shows a list of commands or help for one command
GLOBAL OPTIONS
--version Shows version information
Arguments
You can lookup arguments by calling the Args function on cli.Context, e.g.:
package main
import (
"fmt"
"os"
"gopkg.in/urfave/cli.v2"
)
func main() {
app := &cli.App{
Action: func(c *cli.Context) error {
fmt.Printf("Hello %q", c.Args().Get(0))
return nil
},
}
app.Run(os.Args)
}
Flags
Setting and querying flags is simple.
package main
import (
"fmt"
"os"
"gopkg.in/urfave/cli.v2"
)
func main() {
app := &cli.App{
Flags: []cli.Flag {
&cli.StringFlag{
Name: "lang",
Value: "english",
Usage: "language for the greeting",
},
},
Action: func(c *cli.Context) error {
name := "Nefertiti"
if c.NArg() > 0 {
name = c.Args().Get(0)
}
if c.String("lang") == "spanish" {
fmt.Println("Hola", name)
} else {
fmt.Println("Hello", name)
}
return nil
},
}
app.Run(os.Args)
}
You can also set a destination variable for a flag, to which the content will be scanned.
package main
import (
"os"
"fmt"
"gopkg.in/urfave/cli.v2"
)
func main() {
var language string
app := &cli.App{
Flags: []cli.Flag {
&cli.StringFlag{
Name: "lang",
Value: "english",
Usage: "language for the greeting",
Destination: &language,
},
},
Action: func(c *cli.Context) error {
name := "someone"
if c.NArg() > 0 {
name = c.Args().Get(0)
}
if language == "spanish" {
fmt.Println("Hola", name)
} else {
fmt.Println("Hello", name)
}
return nil
},
}
app.Run(os.Args)
}
See full list of flags at http://godoc.org/github.com/urfave/cli
Placeholder Values
Sometimes it's useful to specify a flag's value within the usage string itself. Such placeholders are indicated with back quotes.
For example this:
package main
import (
"os"
"gopkg.in/urfave/cli.v2"
)
func main() {
app := &cli.App{
Flags: []cli.Flag{
&cli.StringFlag{
Name: "config",
Aliases: []string{"c"},
Usage: "Load configuration from `FILE`",
},
},
}
app.Run(os.Args)
}
Will result in help output like:
--config FILE, -c FILE Load configuration from FILE
Note that only the first placeholder is used. Subsequent back-quoted words will be left as-is.
Alternate Names
You can set alternate (or short) names for flags by providing a comma-delimited
list for the Name. e.g.
package main
import (
"os"
"gopkg.in/urfave/cli.v2"
)
func main() {
app := &cli.App{
Flags: []cli.Flag {
&cli.StringFlag{
Name: "lang",
Aliases: []string{"l"},
Value: "english",
Usage: "language for the greeting",
},
},
}
app.Run(os.Args)
}
That flag can then be set with --lang spanish or -l spanish. Note that
giving two different forms of the same flag in the same command invocation is an
error.
Ordering
Flags for the application and commands are shown in the order they are defined.
However, it's possible to sort them from outside this library by using FlagsByName
or CommandsByName with sort.
For example this:
package main
import (
"os"
"sort"
"github.com/urfave/cli"
)
func main() {
app := &cli.App{
Flags: []cli.Flag{
&cli.StringFlag{
Name: "lang, l",
Value: "english",
Usage: "Language for the greeting",
},
&cli.StringFlag{
Name: "config, c",
Usage: "Load configuration from `FILE`",
},
},
Commands: []*cli.Command{
{
Name: "complete",
Aliases: []string{"c"},
Usage: "complete a task on the list",
Action: func(c *cli.Context) error {
return nil
},
},
{
Name: "add",
Aliases: []string{"a"},
Usage: "add a task to the list",
Action: func(c *cli.Context) error {
return nil
},
},
},
}
sort.Sort(cli.FlagsByName(app.Flags))
sort.Sort(cli.CommandsByName(app.Commands))
app.Run(os.Args)
}
Will result in help output like:
--config FILE, -c FILE Load configuration from FILE
--lang value, -l value Language for the greeting (default: "english")
Values from the Environment
You can also have the default value set from the environment via EnvVars. e.g.
package main
import (
"os"
"gopkg.in/urfave/cli.v2"
)
func main() {
app := &cli.App{
Flags: []cli.Flag {
&cli.StringFlag{
Name: "lang",
Aliases: []string{"l"},
Value: "english",
Usage: "language for the greeting",
EnvVars: []string{"APP_LANG"},
},
},
}
app.Run(os.Args)
}
If EnvVars contains more than one string, the first environment variable that
resolves is used as the default.
package main
import (
"os"
"gopkg.in/urfave/cli.v2"
)
func main() {
app := &cli.App{
Flags: []cli.Flag{
&cli.StringFlag{
Name: "lang",
Aliases: []string{"l"},
Value: "english",
Usage: "language for the greeting",
EnvVars: []string{"LEGACY_COMPAT_LANG", "APP_LANG", "LANG"},
},
},
}
app.Run(os.Args)
}
Values from alternate input sources (YAML, TOML, and others)
There is a separate package altsrc that adds support for getting flag values from other file input sources.
Currently supported input source formats:
- YAML
- TOML
In order to get values for a flag from an alternate input source the following code would be added to wrap an existing cli.Flag like below:
altsrc.NewIntFlag(&cli.IntFlag{Name: "test"})
Initialization must also occur for these flags. Below is an example initializing getting data from a yaml file below.
command.Before = altsrc.InitInputSourceWithContext(command.Flags, NewYamlSourceFromFlagFunc("load"))
The code above will use the "load" string as a flag name to get the file name of a yaml file from the cli.Context. It will then use that file name to initialize the yaml input source for any flags that are defined on that command. As a note the "load" flag used would also have to be defined on the command flags in order for this code snipped to work.
Currently only the aboved specified formats are supported but developers can add support for other input sources by implementing the altsrc.InputSourceContext for their given sources.
Here is a more complete sample of a command using YAML support:
package notmain
import (
"fmt"
"os"
"gopkg.in/urfave/cli.v2"
"gopkg.in/urfave/cli.v2/altsrc"
)
func main() {
flags := []cli.Flag{
altsrc.NewIntFlag(&cli.IntFlag{Name: "test"}),
&cli.StringFlag{Name: "load"},
}
app := &cli.App{
Action: func(c *cli.Context) error {
fmt.Println("yaml ist rad")
return nil
},
Before: altsrc.InitInputSourceWithContext(flags, altsrc.NewYamlSourceFromFlagFunc("load")),
Flags: flags,
}
app.Run(os.Args)
}
Default Values for help output
Sometimes it's useful to specify a flag's default help-text value within the flag declaration. This can be useful if the default value for a flag is a computed value. The default value can be set via the DefaultText struct field.
For example this:
package main
import (
"os"
"gopkg.in/urfave/cli.v2"
)
func main() {
app := &cli.App{
Flags: []cli.Flag{
&cli.IntFlag{
Name: "port",
Usage: "Use a randomized port",
Value: 0,
DefaultText: "random",
},
},
}
app.Run(os.Args)
}
Will result in help output like:
--port value Use a randomized port (default: random)
Subcommands
Subcommands can be defined for a more git-like command line app.
package main
import (
"fmt"
"os"
"gopkg.in/urfave/cli.v2"
)
func main() {
app := &cli.App{
Commands: []*cli.Command{
{
Name: "add",
Aliases: []string{"a"},
Usage: "add a task to the list",
Action: func(c *cli.Context) error {
fmt.Println("added task: ", c.Args().First())
return nil
},
},
{
Name: "complete",
Aliases: []string{"c"},
Usage: "complete a task on the list",
Action: func(c *cli.Context) error {
fmt.Println("completed task: ", c.Args().First())
return nil
},
},
{
Name: "template",
Aliases: []string{"t"},
Usage: "options for task templates",
Subcommands: []*cli.Command{
{
Name: "add",
Usage: "add a new template",
Action: func(c *cli.Context) error {
fmt.Println("new task template: ", c.Args().First())
return nil
},
},
{
Name: "remove",
Usage: "remove an existing template",
Action: func(c *cli.Context) error {
fmt.Println("removed task template: ", c.Args().First())
return nil
},
},
},
},
},
}
app.Run(os.Args)
}
Subcommands categories
For additional organization in apps that have many subcommands, you can associate a category for each command to group them together in the help output.
E.g.
package main
import (
"os"
"gopkg.in/urfave/cli.v2"
)
func main() {
app := &cli.App{
Commands: []*cli.Command{
{
Name: "noop",
},
{
Name: "add",
Category: "template",
},
{
Name: "remove",
Category: "template",
},
},
}
app.Run(os.Args)
}
Will include:
COMMANDS:
noop
Template actions:
add
remove
Exit code
Calling App.Run will not automatically call os.Exit, which means that by
default the exit code will "fall through" to being 0. An explicit exit code
may be set by returning a non-nil error that fulfills cli.ExitCoder, or a
cli.MultiError that includes an error that fulfills cli.ExitCoder, e.g.:
package main
import (
"os"
"gopkg.in/urfave/cli.v2"
)
func main() {
app := &cli.App{
Flags: []cli.Flag{
&cli.BoolFlag{
Name: "ginger-crouton",
Value: true,
Usage: "is it in the soup?",
},
},
Action: func(ctx *cli.Context) error {
if !ctx.Bool("ginger-crouton") {
return cli.Exit("it is not in the soup", 86)
}
return nil
},
}
app.Run(os.Args)
}
Shell Completion
You can enable completion commands by setting the EnableShellCompletion
flag on the App object. By default, this setting will only auto-complete to
show an app's subcommands, but you can write your own completion methods for
the App or its subcommands.
package main
import (
"fmt"
"os"
"gopkg.in/urfave/cli.v2"
)
func main() {
tasks := []string{"cook", "clean", "laundry", "eat", "sleep", "code"}
app := &cli.App{
EnableShellCompletion: true,
Commands: []*cli.Command{
{
Name: "complete",
Aliases: []string{"c"},
Usage: "complete a task on the list",
Action: func(c *cli.Context) error {
fmt.Println("completed task: ", c.Args().First())
return nil
},
ShellComplete: func(c *cli.Context) {
// This will complete if no args are passed
if c.NArg() > 0 {
return
}
for _, t := range tasks {
fmt.Println(t)
}
},
},
},
}
app.Run(os.Args)
}
Enabling
You can generate bash or zsh completion code by using the flag --init-completion bash or --init-completion zsh.
To setup for bash:
eval "`myprogram --init-completion bash`"
Alternatively, you can put the completion code in your .bashrc file:
myprogram --init-completion bash >> ~/.bashrc
Distribution
Copy autocomplete/bash_autocomplete into /etc/bash_completion.d/ and rename
it to the name of the program you wish to add autocomplete support for (or
automatically install it there if you are distributing a package). Don't forget
to source the file to make it active in the current shell.
sudo cp src/bash_autocomplete /etc/bash_completion.d/<myprogram>
source /etc/bash_completion.d/<myprogram>
Alternatively, you can just document that users should source the generic
autocomplete/bash_autocomplete in their bash configuration with $PROG set
to the name of their program (as above).
Customization
The default shell completion flag (--generate-completion) is defined as
cli.GenerateCompletionFlag, and may be redefined if desired, e.g.:
package main
import (
"os"
"gopkg.in/urfave/cli.v2"
)
func main() {
cli.GenerateCompletionFlag = &cli.BoolFlag{
Name: "compgen",
Hidden: true,
}
app := &cli.App{
EnableShellCompletion: true,
Commands: []*cli.Command{
{
Name: "wat",
},
},
}
app.Run(os.Args)
}
Generated Help Text
The default help flag (-h/--help) is defined as cli.HelpFlag and is checked
by the cli internals in order to print generated help text for the app, command,
or subcommand, and break execution.
Customization
All of the help text generation may be customized, and at multiple levels. The
templates are exposed as variables AppHelpTemplate, CommandHelpTemplate, and
SubcommandHelpTemplate which may be reassigned or augmented, and full override
is possible by assigning a compatible func to the cli.HelpPrinter variable,
e.g.:
package main
import (
"fmt"
"io"
"os"
"gopkg.in/urfave/cli.v2"
)
func main() {
// EXAMPLE: Append to an existing template
cli.AppHelpTemplate = fmt.Sprintf(`%s
WEBSITE: http://awesometown.example.com
SUPPORT: support@awesometown.example.com
`, cli.AppHelpTemplate)
// EXAMPLE: Override a template
cli.AppHelpTemplate = `NAME:
{{.Name}} - {{.Usage}}
USAGE:
{{.HelpName}} {{if .VisibleFlags}}[global options]{{end}}{{if .Commands}} command [command options]{{end}} {{if .ArgsUsage}}{{.ArgsUsage}}{{else}}[arguments...]{{end}}
{{if len .Authors}}
AUTHOR:
{{range .Authors}}{{ . }}{{end}}
{{end}}{{if .Commands}}
COMMANDS:
{{range .Commands}}{{if not .HideHelp}} {{join .Names ", "}}{{ "\t"}}{{.Usage}}{{ "\n" }}{{end}}{{end}}{{end}}{{if .VisibleFlags}}
GLOBAL OPTIONS:
{{range .VisibleFlags}}{{.}}
{{end}}{{end}}{{if .Copyright }}
COPYRIGHT:
{{.Copyright}}
{{end}}{{if .Version}}
VERSION:
{{.Version}}
{{end}}
`
// EXAMPLE: Replace the `HelpPrinter` func
cli.HelpPrinter = func(w io.Writer, templ string, data interface{}) {
fmt.Println("Ha HA. I pwnd the help!!1")
}
(&cli.App{}).Run(os.Args)
}
The default flag may be customized to something other than -h/--help by
setting cli.HelpFlag, e.g.:
package main
import (
"os"
"gopkg.in/urfave/cli.v2"
)
func main() {
cli.HelpFlag = &cli.BoolFlag{
Name: "haaaaalp", Aliases: []string{"halp"},
Usage: "HALP",
EnvVars: []string{"SHOW_HALP", "HALPPLZ"},
}
(&cli.App{}).Run(os.Args)
}
Version Flag
The default version flag (-v/--version) is defined as cli.VersionFlag, which
is checked by the cli internals in order to print the App.Version via
cli.VersionPrinter and break execution.
Customization
The default flag may be customized to something other than -v/--version by
setting cli.VersionFlag, e.g.:
package main
import (
"os"
"gopkg.in/urfave/cli.v2"
)
func main() {
cli.VersionFlag = &cli.BoolFlag{
Name: "print-version", Aliases: []string{"V"},
Usage: "print only the version",
}
app := &cli.App{
Name: "partay",
Version: "v19.99.0",
}
app.Run(os.Args)
}
Alternatively, the version printer at cli.VersionPrinter may be overridden, e.g.:
package main
import (
"fmt"
"os"
"gopkg.in/urfave/cli.v2"
)
var (
Revision = "fafafaf"
)
func main() {
cli.VersionPrinter = func(c *cli.Context) {
fmt.Printf("version=%s revision=%s\n", c.App.Version, Revision)
}
app := &cli.App{
Name: "partay",
Version: "v19.99.0",
}
app.Run(os.Args)
}
Full API Example
Notice: This is a contrived (functioning) example meant strictly for API demonstration purposes. Use of one's imagination is encouraged.
package main
import (
"errors"
"flag"
"fmt"
"io"
"io/ioutil"
"os"
"time"
"gopkg.in/urfave/cli.v2"
)
func init() {
cli.AppHelpTemplate += "\nCUSTOMIZED: you bet ur muffins\n"
cli.CommandHelpTemplate += "\nYMMV\n"
cli.SubcommandHelpTemplate += "\nor something\n"
cli.HelpFlag = &cli.BoolFlag{Name: "halp"}
cli.GenerateCompletionFlag = &cli.BoolFlag{Name: "compgen", Hidden: true}
cli.VersionFlag = &cli.BoolFlag{Name: "print-version", Aliases: []string{"V"}}
cli.HelpPrinter = func(w io.Writer, templ string, data interface{}) {
fmt.Fprintf(w, "best of luck to you\n")
}
cli.VersionPrinter = func(c *cli.Context) {
fmt.Fprintf(c.App.Writer, "version=%s\n", c.App.Version)
}
cli.OsExiter = func(c int) {
fmt.Fprintf(cli.ErrWriter, "refusing to exit %d\n", c)
}
cli.ErrWriter = ioutil.Discard
cli.FlagStringer = func(fl cli.Flag) string {
return fmt.Sprintf("\t\t%s", fl.Names()[0])
}
}
type hexWriter struct{}
func (w *hexWriter) Write(p []byte) (int, error) {
for _, b := range p {
fmt.Printf("%x", b)
}
fmt.Printf("\n")
return len(p), nil
}
type genericType struct {
s string
}
func (g *genericType) Set(value string) error {
g.s = value
return nil
}
func (g *genericType) String() string {
return g.s
}
func main() {
app := cli.App{
Name: "kənˈtrīv",
Version: "v19.99.0",
Compiled: time.Now(),
Authors: []*cli.Author{
&cli.Author{
Name: "Example Human",
Email: "human@example.com",
},
},
Copyright: "(c) 1999 Serious Enterprise",
HelpName: "contrive",
Usage: "demonstrate available API",
UsageText: "contrive - demonstrating the available API",
ArgsUsage: "[args and such]",
Commands: []*cli.Command{
&cli.Command{
Name: "doo",
Aliases: []string{"do"},
Category: "motion",
Usage: "do the doo",
UsageText: "doo - does the dooing",
Description: "no really, there is a lot of dooing to be done",
ArgsUsage: "[arrgh]",
Flags: []cli.Flag{
&cli.BoolFlag{Name: "forever", Aliases: []string{"forevvarr"}},
},
Subcommands: []*cli.Command{
&cli.Command{
Name: "wop",
Action: wopAction,
},
},
SkipFlagParsing: false,
HideHelp: false,
Hidden: false,
HelpName: "doo!",
ShellComplete: func(c *cli.Context) {
fmt.Fprintf(c.App.Writer, "--better\n")
},
Before: func(c *cli.Context) error {
fmt.Fprintf(c.App.Writer, "brace for impact\n")
return nil
},
After: func(c *cli.Context) error {
fmt.Fprintf(c.App.Writer, "did we lose anyone?\n")
return nil
},
Action: func(c *cli.Context) error {
c.Command.FullName()
c.Command.HasName("wop")
c.Command.Names()
c.Command.VisibleFlags()
fmt.Fprintf(c.App.Writer, "dodododododoodododddooooododododooo\n")
if c.Bool("forever") {
c.Command.Run(c)
}
return nil
},
OnUsageError: func(c *cli.Context, err error, isSubcommand bool) error {
fmt.Fprintf(c.App.Writer, "for shame\n")
return err
},
},
},
Flags: []cli.Flag{
&cli.BoolFlag{Name: "fancy"},
&cli.BoolFlag{Value: true, Name: "fancier"},
&cli.DurationFlag{Name: "howlong", Aliases: []string{"H"}, Value: time.Second * 3},
&cli.Float64Flag{Name: "howmuch"},
&cli.GenericFlag{Name: "wat", Value: &genericType{}},
&cli.Int64Flag{Name: "longdistance"},
&cli.Int64SliceFlag{Name: "intervals"},
&cli.IntFlag{Name: "distance"},
&cli.IntSliceFlag{Name: "times"},
&cli.StringFlag{Name: "dance-move", Aliases: []string{"d"}},
&cli.StringSliceFlag{Name: "names", Aliases: []string{"N"}},
&cli.UintFlag{Name: "age"},
&cli.Uint64Flag{Name: "bigage"},
},
EnableShellCompletion: true,
HideHelp: false,
HideVersion: false,
ShellComplete: func(c *cli.Context) {
fmt.Fprintf(c.App.Writer, "lipstick\nkiss\nme\nlipstick\nringo\n")
},
Before: func(c *cli.Context) error {
fmt.Fprintf(c.App.Writer, "HEEEERE GOES\n")
return nil
},
After: func(c *cli.Context) error {
fmt.Fprintf(c.App.Writer, "Phew!\n")
return nil
},
CommandNotFound: func(c *cli.Context, command string) {
fmt.Fprintf(c.App.Writer, "Thar be no %q here.\n", command)
},
OnUsageError: func(c *cli.Context, err error, isSubcommand bool) error {
if isSubcommand {
return err
}
fmt.Fprintf(c.App.Writer, "WRONG: %#v\n", err)
return nil
},
Action: func(c *cli.Context) error {
cli.DefaultAppComplete(c)
cli.HandleExitCoder(errors.New("not an exit coder, though"))
cli.ShowAppHelp(c)
cli.ShowCommandCompletions(c, "nope")
cli.ShowCommandHelp(c, "also-nope")
cli.ShowCompletions(c)
cli.ShowSubcommandHelp(c)
cli.ShowVersion(c)
categories := c.App.Categories
categories.AddCommand("sounds", &cli.Command{
Name: "bloop",
})
for _, category := range c.App.Categories.Categories() {
fmt.Fprintf(c.App.Writer, "%s\n", category.Name)
fmt.Fprintf(c.App.Writer, "%#v\n", category.VisibleCommands())
fmt.Fprintf(c.App.Writer, "%#v\n", category.VisibleCommands())
}
fmt.Printf("%#v\n", c.App.Command("doo"))
if c.Bool("infinite") {
c.App.Run([]string{"app", "doo", "wop"})
}
if c.Bool("forevar") {
c.App.RunAsSubcommand(c)
}
c.App.Setup()
fmt.Printf("%#v\n", c.App.VisibleCategories())
fmt.Printf("%#v\n", c.App.VisibleCommands())
fmt.Printf("%#v\n", c.App.VisibleFlags())
fmt.Printf("%#v\n", c.Args().First())
if c.Args().Len() > 0 {
fmt.Printf("%#v\n", c.Args().Get(1))
}
fmt.Printf("%#v\n", c.Args().Present())
fmt.Printf("%#v\n", c.Args().Tail())
set := flag.NewFlagSet("contrive", 0)
nc := cli.NewContext(c.App, set, c)
fmt.Printf("%#v\n", nc.Args())
fmt.Printf("%#v\n", nc.Bool("nope"))
fmt.Printf("%#v\n", !nc.Bool("nerp"))
fmt.Printf("%#v\n", nc.Duration("howlong"))
fmt.Printf("%#v\n", nc.Float64("hay"))
fmt.Printf("%#v\n", nc.Generic("bloop"))
fmt.Printf("%#v\n", nc.Int64("bonk"))
fmt.Printf("%#v\n", nc.Int64Slice("burnks"))
fmt.Printf("%#v\n", nc.Int("bips"))
fmt.Printf("%#v\n", nc.IntSlice("blups"))
fmt.Printf("%#v\n", nc.String("snurt"))
fmt.Printf("%#v\n", nc.StringSlice("snurkles"))
fmt.Printf("%#v\n", nc.Uint("flub"))
fmt.Printf("%#v\n", nc.Uint64("florb"))
fmt.Printf("%#v\n", nc.FlagNames())
fmt.Printf("%#v\n", nc.IsSet("wat"))
fmt.Printf("%#v\n", nc.Set("wat", "nope"))
fmt.Printf("%#v\n", nc.NArg())
fmt.Printf("%#v\n", nc.NumFlags())
fmt.Printf("%#v\n", nc.Lineage()[1])
nc.Set("wat", "also-nope")
ec := cli.Exit("ohwell", 86)
fmt.Fprintf(c.App.Writer, "%d", ec.ExitCode())
fmt.Printf("made it!\n")
return ec
},
Metadata: map[string]interface{}{
"layers": "many",
"explicable": false,
"whatever-values": 19.99,
},
}
if os.Getenv("HEXY") != "" {
app.Writer = &hexWriter{}
app.ErrWriter = &hexWriter{}
}
app.Run(os.Args)
}
func wopAction(c *cli.Context) error {
fmt.Fprintf(c.App.Writer, ":wave: over here, eh\n")
return nil
}
Contribution Guidelines
Feel free to put up a pull request to fix a bug or maybe add a feature. I will give it a code review and make sure that it does not break backwards compatibility. If I or any other collaborators agree that it is in line with the vision of the project, we will work with you to get the code into a mergeable state and merge it into the master branch.
If you have contributed something significant to the project, we will most likely add you as a collaborator. As a collaborator you are given the ability to merge others pull requests. It is very important that new code does not break existing code, so be careful about what code you do choose to merge.
If you feel like you have contributed to the project but have not yet been added as a collaborator, we probably forgot to add you, please open an issue.
Documentation
¶
Overview ¶
Package cli provides a minimal framework for creating and organizing command line Go applications. cli is designed to be easy to understand and write, the most simple cli application can be written as follows:
func main() {
(&cli.App{}).Run(os.Args)
}
Of course this application does not do much, so let's make this an actual application:
func main() {
app := &cli.App{
Name: "greet",
Usage: "say a greeting",
Action: func(c *cli.Context) error {
fmt.Println("Greetings")
return nil
},
}
app.Run(os.Args)
}
Index ¶
- Variables
- func DefaultAppComplete(c *Context)
- func HandleExitCoder(err error)
- func ShowAppHelp(c *Context) (err error)
- func ShowAppHelpAndExit(c *Context, exitCode int)
- func ShowCommandCompletions(ctx *Context, command string)
- func ShowCommandHelp(ctx *Context, command string) error
- func ShowCommandHelpAndExit(c *Context, command string, code int)
- func ShowCompletions(c *Context)
- func ShowSubcommandHelp(c *Context) error
- func ShowVersion(c *Context)
- type ActionFunc
- type AfterFunc
- type App
- func (a *App) Command(name string) *Command
- func (a *App) Run(arguments []string) (err error)
- func (a *App) RunAsSubcommand(ctx *Context) (err error)
- func (a *App) Setup()
- func (a *App) VisibleCategories() []CommandCategory
- func (a *App) VisibleCommands() []*Command
- func (a *App) VisibleFlags() []Flag
- type Args
- type Author
- type BeforeFunc
- type BoolFlag
- type Command
- type CommandCategories
- type CommandCategory
- type CommandNotFoundFunc
- type CommandsByName
- type Context
- func (c *Context) Args() Args
- func (c *Context) Bool(name string) bool
- func (c *Context) Duration(name string) time.Duration
- func (c *Context) FlagNames() []string
- func (c *Context) Float64(name string) float64
- func (c *Context) Float64Slice(name string) []float64
- func (c *Context) Generic(name string) interface{}
- func (c *Context) Int(name string) int
- func (c *Context) Int64(name string) int64
- func (c *Context) Int64Slice(name string) []int64
- func (c *Context) IntSlice(name string) []int
- func (c *Context) IsSet(name string) bool
- func (c *Context) Lineage() []*Context
- func (c *Context) LocalFlagNames() []string
- func (c *Context) NArg() int
- func (c *Context) NumFlags() int
- func (c *Context) Path(name string) string
- func (c *Context) Set(name, value string) error
- func (c *Context) String(name string) string
- func (c *Context) StringSlice(name string) []string
- func (c *Context) Uint(name string) uint
- func (c *Context) Uint64(name string) uint64
- type DurationFlag
- type ErrorFormatter
- type ExitCoder
- type Flag
- type FlagStringFunc
- type FlagsByName
- type Float64Flag
- type Float64Slice
- type Float64SliceFlag
- type Generic
- type GenericFlag
- type Int64Flag
- type Int64Slice
- type Int64SliceFlag
- type IntFlag
- type IntSlice
- type IntSliceFlag
- type MultiError
- type OnUsageErrorFunc
- type PathFlag
- type Serializeder
- type ShellCompleteFunc
- type StringFlag
- type StringSlice
- type StringSliceFlag
- type Uint64Flag
- type UintFlag
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var AppHelpTemplate = `` /* 971-byte string literal not displayed */
AppHelpTemplate is the text template for the Default help topic. cli.go uses text/template to render templates. You can render custom help text by setting this variable.
var CommandHelpTemplate = `` /* 404-byte string literal not displayed */
CommandHelpTemplate is the text template for the command help topic. cli.go uses text/template to render templates. You can render custom help text by setting this variable.
var ErrWriter io.Writer = os.Stderr
ErrWriter is used to write errors to the user. This can be anything implementing the io.Writer interface and defaults to os.Stderr.
var HelpPrinter helpPrinter = printHelp
HelpPrinter is a function that writes the help output. If not set a default is used. The function signature is: func(w io.Writer, templ string, data interface{})
var HelpPrinterCustom helpPrinterCustom = printHelpCustom
HelpPrinterCustom is same as HelpPrinter but takes a custom function for template function map.
var InitCompletionFlag = &StringFlag{
Name: "init-completion",
Usage: "generate completion code. Value must be 'bash' or 'zsh'",
}
InitCompletionFlag generates completion code
var OsExiter = os.Exit
OsExiter is the function used when the app exits. If not set defaults to os.Exit.
var SubcommandHelpTemplate = `` /* 507-byte string literal not displayed */
SubcommandHelpTemplate is the text template for the subcommand help topic. cli.go uses text/template to render templates. You can render custom help text by setting this variable.
var VersionPrinter = printVersion
VersionPrinter prints the version for the App
Functions ¶
func DefaultAppComplete ¶
func DefaultAppComplete(c *Context)
DefaultAppComplete prints the list of subcommands as the default app completion method
func HandleExitCoder ¶
func HandleExitCoder(err error)
HandleExitCoder checks if the error fulfills the ExitCoder interface, and if so prints the error to stderr (if it is non-empty) and calls OsExiter with the given exit code. If the given error is a MultiError, then this func is called on all members of the Errors slice and calls OsExiter with the last exit code.
func ShowAppHelp ¶
ShowAppHelp is an action that displays the help.
func ShowAppHelpAndExit ¶
ShowAppHelpAndExit - Prints the list of subcommands for the app and exits with exit code.
func ShowCommandCompletions ¶
ShowCommandCompletions prints the custom completions for a given command
func ShowCommandHelp ¶
ShowCommandHelp prints help for the given command
func ShowCommandHelpAndExit ¶
ShowCommandHelpAndExit - exits with code after showing help
func ShowCompletions ¶
func ShowCompletions(c *Context)
ShowCompletions prints the lists of commands within a given context
func ShowSubcommandHelp ¶
ShowSubcommandHelp prints help for the given subcommand
Types ¶
type ActionFunc ¶
ActionFunc is the action to execute when no subcommands are specified
func DefaultCommand ¶
func DefaultCommand(name string) ActionFunc
DefaultAppComplete returns an ActionFunc to run a default command if non were passed. Usage: `app.Action = cli.DefaultCommand("command")`
type AfterFunc ¶
AfterFunc is an action to execute after any subcommands are run, but after the subcommand has finished it is run even if Action() panics
type App ¶
type App struct {
// The name of the program. Defaults to path.Base(os.Args[0])
Name string
// Full name of command for help, defaults to Name
HelpName string
// Description of the program.
Usage string
// Text to override the USAGE section of help
UsageText string
// Description of the program argument format.
ArgsUsage string
// Version of the program
Version string
// Description of the program
Description string
// List of commands to execute
Commands []*Command
// List of flags to parse
Flags []Flag
// Boolean to enable shell completion commands
EnableShellCompletion bool
// Boolean to hide built-in help command
HideHelp bool
// Boolean to hide built-in version flag and the VERSION section of help
HideVersion bool
// Categories contains the categorized commands and is populated on app startup
Categories CommandCategories
// An action to execute when the shell completion flag is set
ShellComplete ShellCompleteFunc
// An action to execute before any subcommands are run, but after the context is ready
// If a non-nil error is returned, no subcommands are run
Before BeforeFunc
// An action to execute after any subcommands are run, but after the subcommand has finished
// It is run even if Action() panics
After AfterFunc
// The action to execute when no subcommands are specified
Action ActionFunc
// Execute this function if the proper command cannot be found
CommandNotFound CommandNotFoundFunc
// Execute this function if an usage error occurs
OnUsageError OnUsageErrorFunc
// Compilation date
Compiled time.Time
// List of all authors who contributed
Authors []*Author
// Copyright of the binary if any
Copyright string
// Writer writer to write output to
Writer io.Writer
// ErrWriter writes error output
ErrWriter io.Writer
// Other custom info
Metadata map[string]interface{}
// Carries a function which returns app specific info.
ExtraInfo func() map[string]string
// CustomAppHelpTemplate the text template for app help topic.
// cli.go uses text/template to render templates. You can
// render custom help text by setting this variable.
CustomAppHelpTemplate string
// contains filtered or unexported fields
}
App is the main structure of a cli application.
func (*App) Command ¶
Command returns the named command on App. Returns nil if the command does not exist
func (*App) Run ¶
Run is the entry point to the cli app. Parses the arguments slice and routes to the proper flag/args combination
Example ¶
// set args for examples sake
os.Args = []string{"greet", "--name", "Jeremy"}
app := &App{
Name: "greet",
Flags: []Flag{
&StringFlag{Name: "name", Value: "bob", Usage: "a name to say"},
},
Action: func(c *Context) error {
fmt.Printf("Hello %v\n", c.String("name"))
return nil
},
UsageText: "app [first_arg] [second_arg]",
Authors: []*Author{{Name: "Oliver Allen", Email: "oliver@toyshop.example.com"}},
}
app.Run(os.Args)
Output: Hello Jeremy
Example (AppHelp) ¶
// set args for examples sake
os.Args = []string{"greet", "help"}
app := &App{
Name: "greet",
Version: "0.1.0",
Description: "This is how we describe greet the app",
Authors: []*Author{
{Name: "Harrison", Email: "harrison@lolwut.com"},
{Name: "Oliver Allen", Email: "oliver@toyshop.com"},
},
Flags: []Flag{
&StringFlag{Name: "name", Value: "bob", Usage: "a name to say"},
},
Commands: []*Command{
{
Name: "describeit",
Aliases: []string{"d"},
Usage: "use it to see a description",
Description: "This is how we describe describeit the function",
Action: func(c *Context) error {
fmt.Printf("i like to describe things")
return nil
},
},
},
}
app.Run(os.Args)
Output: NAME: greet - A new cli application USAGE: greet [global options] command [command options] [arguments...] VERSION: 0.1.0 DESCRIPTION: This is how we describe greet the app AUTHORS: Harrison <harrison@lolwut.com> Oliver Allen <oliver@toyshop.com> COMMANDS: describeit, d use it to see a description help, h Shows a list of commands or help for one command GLOBAL OPTIONS: --name value a name to say (default: "bob") --help, -h show help (default: false) --version, -v print the version (default: false)
Example (CommandHelp) ¶
// set args for examples sake
os.Args = []string{"greet", "h", "describeit"}
app := &App{
Name: "greet",
Flags: []Flag{
&StringFlag{Name: "name", Value: "bob", Usage: "a name to say"},
},
Commands: []*Command{
{
Name: "describeit",
Aliases: []string{"d"},
Usage: "use it to see a description",
Description: "This is how we describe describeit the function",
Action: func(c *Context) error {
fmt.Printf("i like to describe things")
return nil
},
},
},
}
app.Run(os.Args)
Output: NAME: greet describeit - use it to see a description USAGE: greet describeit [arguments...] DESCRIPTION: This is how we describe describeit the function
Example (NoAction) ¶
app := App{}
app.Name = "greet"
app.Run([]string{"greet"})
Output: NAME: greet - A new cli application USAGE: greet [global options] command [command options] [arguments...] VERSION: 0.0.0 COMMANDS: help, h Shows a list of commands or help for one command GLOBAL OPTIONS: --help, -h show help (default: false) --version, -v print the version (default: false)
Example (ShellComplete) ¶
// set args for examples sake
os.Args = []string{"greet", fmt.Sprintf("--%s", genCompName())}
app := &App{
Name: "greet",
EnableShellCompletion: true,
Commands: []*Command{
{
Name: "describeit",
Aliases: []string{"d"},
Usage: "use it to see a description",
Description: "This is how we describe describeit the function",
Action: func(c *Context) error {
fmt.Printf("i like to describe things")
return nil
},
}, {
Name: "next",
Usage: "next example",
Description: "more stuff to see when generating shell completion",
Action: func(c *Context) error {
fmt.Printf("the next example")
return nil
},
},
},
}
app.Run(os.Args)
Output: describeit d next help h
Example (Subcommand) ¶
// set args for examples sake
os.Args = []string{"say", "hi", "english", "--name", "Jeremy"}
app := &App{
Name: "say",
Commands: []*Command{
{
Name: "hello",
Aliases: []string{"hi"},
Usage: "use it to see a description",
Description: "This is how we describe hello the function",
Subcommands: []*Command{
{
Name: "english",
Aliases: []string{"en"},
Usage: "sends a greeting in english",
Description: "greets someone in english",
Flags: []Flag{
&StringFlag{
Name: "name",
Value: "Bob",
Usage: "Name of the person to greet",
},
},
Action: func(c *Context) error {
fmt.Println("Hello,", c.String("name"))
return nil
},
},
},
},
},
}
app.Run(os.Args)
Output: Hello, Jeremy
Example (SubcommandNoAction) ¶
app := &App{
Name: "greet",
Commands: []*Command{
{
Name: "describeit",
Aliases: []string{"d"},
Usage: "use it to see a description",
Description: "This is how we describe describeit the function",
},
},
}
app.Run([]string{"greet", "describeit"})
Output: NAME: greet describeit - use it to see a description USAGE: greet describeit [command options] [arguments...] DESCRIPTION: This is how we describe describeit the function OPTIONS: --help, -h show help (default: false)
func (*App) RunAsSubcommand ¶
RunAsSubcommand invokes the subcommand given the context, parses ctx.Args() to generate command-specific flags
func (*App) Setup ¶
func (a *App) Setup()
Setup runs initialization code to ensure all data structures are ready for `Run` or inspection prior to `Run`. It is internally called by `Run`, but will return early if setup has already happened.
func (*App) VisibleCategories ¶
func (a *App) VisibleCategories() []CommandCategory
VisibleCategories returns a slice of categories and commands that are Hidden=false
func (*App) VisibleCommands ¶
VisibleCommands returns a slice of the Commands with Hidden=false
func (*App) VisibleFlags ¶
VisibleFlags returns a slice of the Flags with Hidden=false
type Args ¶
type Args interface {
// Get returns the nth argument, or else a blank string
Get(n int) string
// First returns the first argument, or else a blank string
First() string
// Tail returns the rest of the arguments (not the first one)
// or else an empty string slice
Tail() []string
// Len returns the length of the wrapped slice
Len() int
// Present checks if there are any arguments present
Present() bool
// Slice returns a copy of the internal slice
Slice() []string
}
type BeforeFunc ¶
BeforeFunc is an action to execute before any subcommands are run, but after the context is ready if a non-nil error is returned, no subcommands are run
type BoolFlag ¶
type BoolFlag struct {
Name string
Aliases []string
Usage string
EnvVars []string
Hidden bool
Value bool
DefaultText string
Destination *bool
}
BoolFlag is a flag with type bool
func (*BoolFlag) ApplyWithError ¶
ApplyWithError populates the flag given the flag set and environment
type Command ¶
type Command struct {
// The name of the command
Name string
// A list of aliases for the command
Aliases []string
// A short description of the usage of this command
Usage string
// Custom text to show on USAGE section of help
UsageText string
// A longer explanation of how the command works
Description string
// A short description of the arguments of this command
ArgsUsage string
// The category the command is part of
Category string
// The function to call when checking for shell command completions
ShellComplete ShellCompleteFunc
// An action to execute before any sub-subcommands are run, but after the context is ready
// If a non-nil error is returned, no sub-subcommands are run
Before BeforeFunc
// An action to execute after any subcommands are run, but after the subcommand has finished
// It is run even if Action() panics
After AfterFunc
// The function to call when this command is invoked
Action ActionFunc
// Execute this function if a usage error occurs.
OnUsageError OnUsageErrorFunc
// List of child commands
Subcommands []*Command
// List of flags to parse
Flags []Flag
// Treat all flags as normal arguments if true
SkipFlagParsing bool
// Boolean to hide built-in help command
HideHelp bool
// Boolean to hide this command from help or completion
Hidden bool
// Full name of command for help, defaults to full command name, including parent commands.
HelpName string
// CustomHelpTemplate the text template for the command help topic.
// cli.go uses text/template to render templates. You can
// render custom help text by setting this variable.
CustomHelpTemplate string
// contains filtered or unexported fields
}
Command is a subcommand for a cli.App.
func (*Command) FullName ¶
FullName returns the full name of the command. For subcommands this ensures that parent commands are part of the command path
func (*Command) Run ¶
Run invokes the command given the context, parses ctx.Args() to generate command-specific flags
func (*Command) VisibleFlags ¶
VisibleFlags returns a slice of the Flags with Hidden=false
type CommandCategories ¶
type CommandCategories interface {
// AddCommand adds a command to a category, creating a new category if necessary.
AddCommand(category string, command *Command)
// Categories returns a copy of the category slice
Categories() []CommandCategory
}
type CommandCategory ¶
type CommandCategory interface {
// Name returns the category name string
Name() string
// VisibleCommands returns a slice of the Commands with Hidden=false
VisibleCommands() []*Command
}
CommandCategory is a category containing commands.
type CommandNotFoundFunc ¶
CommandNotFoundFunc is executed if the proper command cannot be found
type CommandsByName ¶
type CommandsByName []*Command
func (CommandsByName) Len ¶
func (c CommandsByName) Len() int
func (CommandsByName) Less ¶
func (c CommandsByName) Less(i, j int) bool
func (CommandsByName) Swap ¶
func (c CommandsByName) Swap(i, j int)
type Context ¶
type Context struct {
context.Context
App *App
Command *Command
// contains filtered or unexported fields
}
Context is a type that is passed through to each Handler action in a cli application. Context can be used to retrieve context-specific args and parsed command-line options.
func NewContext ¶
NewContext creates a new context. For use in when invoking an App or Command action.
func (*Context) Duration ¶
Duration looks up the value of a local DurationFlag, returns 0 if not found
func (*Context) FlagNames ¶
FlagNames returns a slice of flag names used by the this context and all of its parent contexts.
func (*Context) Float64Slice ¶
Float64Slice looks up the value of a local Float64SliceFlag, returns nil if not found
func (*Context) Generic ¶
Generic looks up the value of a local GenericFlag, returns nil if not found
func (*Context) Int64Slice ¶
Int64Slice looks up the value of a local Int64SliceFlag, returns nil if not found
func (*Context) IntSlice ¶
IntSlice looks up the value of a local IntSliceFlag, returns nil if not found
func (*Context) Lineage ¶
Lineage returns *this* context and all of its ancestor contexts in order from child to parent
func (*Context) LocalFlagNames ¶
LocalFlagNames returns a slice of flag names used in this context.
func (*Context) StringSlice ¶
StringSlice looks up the value of a local StringSliceFlag, returns nil if not found
type DurationFlag ¶
type DurationFlag struct {
Name string
Aliases []string
Usage string
EnvVars []string
Hidden bool
Value time.Duration
DefaultText string
Destination *time.Duration
}
DurationFlag is a flag with type time.Duration (see https://golang.org/pkg/time/#ParseDuration)
func (*DurationFlag) Apply ¶
func (f *DurationFlag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment Ignores errors
func (*DurationFlag) ApplyWithError ¶
func (f *DurationFlag) ApplyWithError(set *flag.FlagSet) error
ApplyWithError populates the flag given the flag set and environment
func (*DurationFlag) Names ¶
func (f *DurationFlag) Names() []string
Names returns the names of the flag
func (*DurationFlag) String ¶
func (f *DurationFlag) String() string
String returns a readable representation of this value (for usage defaults)
type ErrorFormatter ¶
type Flag ¶
type Flag interface {
fmt.Stringer
// Apply Flag settings to the given flag set
Apply(*flag.FlagSet)
Names() []string
}
Flag is a common interface related to parsing flags in cli. For more advanced flag parsing techniques, it is recommended that this interface be implemented.
GenerateCompletionFlag enables completion for all commands and subcommands
HelpFlag prints the help for all commands and subcommands. Set to nil to disable the flag. The subcommand will still be added unless HideHelp is set to true.
type FlagStringFunc ¶
FlagStringFunc is used by the help generation to display a flag, which is expected to be a single line.
var FlagStringer FlagStringFunc = stringifyFlag
FlagStringer converts a flag definition to a string. This is used by help to display a flag.
type FlagsByName ¶
type FlagsByName []Flag
FlagsByName is a slice of Flag.
func (FlagsByName) Len ¶
func (f FlagsByName) Len() int
func (FlagsByName) Less ¶
func (f FlagsByName) Less(i, j int) bool
func (FlagsByName) Swap ¶
func (f FlagsByName) Swap(i, j int)
type Float64Flag ¶
type Float64Flag struct {
Name string
Aliases []string
Usage string
EnvVars []string
Hidden bool
Value float64
DefaultText string
Destination *float64
}
Float64Flag is a flag with type float64
func (*Float64Flag) Apply ¶
func (f *Float64Flag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment Ignores errors
func (*Float64Flag) ApplyWithError ¶
func (f *Float64Flag) ApplyWithError(set *flag.FlagSet) error
ApplyWithError populates the flag given the flag set and environment
func (*Float64Flag) Names ¶
func (f *Float64Flag) Names() []string
Names returns the names of the flag
func (*Float64Flag) String ¶
func (f *Float64Flag) String() string
String returns a readable representation of this value (for usage defaults)
type Float64Slice ¶
type Float64Slice struct {
// contains filtered or unexported fields
}
Float64Slice is an opaque type for []float64 to satisfy flag.Value
func NewFloat64Slice ¶
func NewFloat64Slice(defaults ...float64) *Float64Slice
NewFloat64Slice makes a *Float64Slice with default values
func (*Float64Slice) Serialized ¶
func (f *Float64Slice) Serialized() string
Serialized allows Float64Slice to fulfill Serializeder
func (*Float64Slice) Set ¶
func (f *Float64Slice) Set(value string) error
Set parses the value into a float64 and appends it to the list of values
func (*Float64Slice) String ¶
func (f *Float64Slice) String() string
String returns a readable representation of this value (for usage defaults)
func (*Float64Slice) Value ¶
func (f *Float64Slice) Value() []float64
Value returns the slice of float64s set by this flag
type Float64SliceFlag ¶
type Float64SliceFlag struct {
Name string
Aliases []string
Usage string
EnvVars []string
Hidden bool
Value *Float64Slice
DefaultText string
}
Float64SliceFlag is a flag with type *Float64Slice
func (*Float64SliceFlag) Apply ¶
func (f *Float64SliceFlag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment Ignores errors
func (*Float64SliceFlag) ApplyWithError ¶
func (f *Float64SliceFlag) ApplyWithError(set *flag.FlagSet) error
ApplyWithError populates the flag given the flag set and environment
func (*Float64SliceFlag) Names ¶
func (f *Float64SliceFlag) Names() []string
Names returns the names of the flag
func (*Float64SliceFlag) String ¶
func (f *Float64SliceFlag) String() string
String returns a readable representation of this value (for usage defaults)
type GenericFlag ¶
type GenericFlag struct {
Name string
Aliases []string
Usage string
EnvVars []string
Hidden bool
Value Generic
DefaultText string
}
GenericFlag is a flag with type Generic
func (*GenericFlag) Apply ¶
func (f *GenericFlag) Apply(set *flag.FlagSet)
Apply takes the flagset and calls Set on the generic flag with the value provided by the user for parsing by the flag Ignores parsing errors
func (*GenericFlag) ApplyWithError ¶
func (f *GenericFlag) ApplyWithError(set *flag.FlagSet) error
ApplyWithError takes the flagset and calls Set on the generic flag with the value provided by the user for parsing by the flag
func (*GenericFlag) Names ¶
func (f *GenericFlag) Names() []string
Names returns the names of the flag
func (*GenericFlag) String ¶
func (f *GenericFlag) String() string
String returns a readable representation of this value (for usage defaults)
type Int64Flag ¶
type Int64Flag struct {
Name string
Aliases []string
Usage string
EnvVars []string
Hidden bool
Value int64
DefaultText string
Destination *int64
}
Int64Flag is a flag with type int64
func (*Int64Flag) Apply ¶
Apply populates the flag given the flag set and environment Ignores errors
func (*Int64Flag) ApplyWithError ¶
ApplyWithError populates the flag given the flag set and environment
type Int64Slice ¶
type Int64Slice struct {
// contains filtered or unexported fields
}
Int64Slice is an opaque type for []int to satisfy flag.Value
func NewInt64Slice ¶
func NewInt64Slice(defaults ...int64) *Int64Slice
NewInt64Slice makes an *Int64Slice with default values
func (*Int64Slice) Get ¶
func (f *Int64Slice) Get() interface{}
Get returns the slice of ints set by this flag
func (*Int64Slice) Serialized ¶
func (f *Int64Slice) Serialized() string
Serialized allows Int64Slice to fulfill Serializeder
func (*Int64Slice) Set ¶
func (f *Int64Slice) Set(value string) error
Set parses the value into an integer and appends it to the list of values
func (*Int64Slice) String ¶
func (f *Int64Slice) String() string
String returns a readable representation of this value (for usage defaults)
func (*Int64Slice) Value ¶
func (f *Int64Slice) Value() []int64
Value returns the slice of ints set by this flag
type Int64SliceFlag ¶
type Int64SliceFlag struct {
Name string
Aliases []string
Usage string
EnvVars []string
Hidden bool
Value *Int64Slice
DefaultText string
}
Int64SliceFlag is a flag with type *Int64Slice
func (*Int64SliceFlag) Apply ¶
func (f *Int64SliceFlag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment Ignores errors
func (*Int64SliceFlag) ApplyWithError ¶
func (f *Int64SliceFlag) ApplyWithError(set *flag.FlagSet) error
ApplyWithError populates the flag given the flag set and environment
func (*Int64SliceFlag) Names ¶
func (f *Int64SliceFlag) Names() []string
Names returns the names of the flag
func (*Int64SliceFlag) String ¶
func (f *Int64SliceFlag) String() string
String returns a readable representation of this value (for usage defaults)
type IntFlag ¶
type IntFlag struct {
Name string
Aliases []string
Usage string
EnvVars []string
Hidden bool
Value int
DefaultText string
Destination *int
}
IntFlag is a flag with type int
func (*IntFlag) ApplyWithError ¶
ApplyWithError populates the flag given the flag set and environment
type IntSlice ¶
type IntSlice struct {
// contains filtered or unexported fields
}
IntSlice wraps an []int to satisfy flag.Value
func NewIntSlice ¶
NewIntSlice makes an *IntSlice with default values
func (*IntSlice) Get ¶
func (f *IntSlice) Get() interface{}
Get returns the slice of ints set by this flag
func (*IntSlice) Serialized ¶
Serialized allows IntSlice to fulfill Serializeder
type IntSliceFlag ¶
type IntSliceFlag struct {
Name string
Aliases []string
Usage string
EnvVars []string
Hidden bool
Value *IntSlice
DefaultText string
}
IntSliceFlag is a flag with type *IntSlice
func (*IntSliceFlag) Apply ¶
func (f *IntSliceFlag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment Ignores errors
func (*IntSliceFlag) ApplyWithError ¶
func (f *IntSliceFlag) ApplyWithError(set *flag.FlagSet) error
ApplyWithError populates the flag given the flag set and environment
func (*IntSliceFlag) Names ¶
func (f *IntSliceFlag) Names() []string
Names returns the names of the flag
func (*IntSliceFlag) String ¶
func (f *IntSliceFlag) String() string
String returns a readable representation of this value (for usage defaults)
type MultiError ¶
MultiError is an error that wraps multiple errors.
type OnUsageErrorFunc ¶
OnUsageErrorFunc is executed if an usage error occurs. This is useful for displaying customized usage error messages. This function is able to replace the original error messages. If this function is not set, the "Incorrect usage" is displayed and the execution is interrupted.
type PathFlag ¶
type PathFlag struct {
Name string
Aliases []string
Usage string
EnvVars []string
Hidden bool
Value string
DefaultText string
Destination *string
}
PathFlag is a flag with type string
func (*PathFlag) ApplyWithError ¶
ApplyWithError populates the flag given the flag set and environment
type Serializeder ¶
type Serializeder interface {
Serialized() string
}
Serializeder is used to circumvent the limitations of flag.FlagSet.Set
type ShellCompleteFunc ¶
type ShellCompleteFunc func(*Context)
ShellCompleteFunc is an action to execute when the shell completion flag is set
type StringFlag ¶
type StringFlag struct {
Name string
Aliases []string
Usage string
EnvVars []string
Hidden bool
Value string
DefaultText string
Destination *string
}
StringFlag is a flag with type string
func (*StringFlag) Apply ¶
func (f *StringFlag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment Ignores errors
func (*StringFlag) ApplyWithError ¶
func (f *StringFlag) ApplyWithError(set *flag.FlagSet) error
ApplyWithError populates the flag given the flag set and environment
func (*StringFlag) Names ¶
func (f *StringFlag) Names() []string
Names returns the names of the flag
func (*StringFlag) String ¶
func (f *StringFlag) String() string
String returns a readable representation of this value (for usage defaults)
type StringSlice ¶
type StringSlice struct {
// contains filtered or unexported fields
}
StringSlice wraps a []string to satisfy flag.Value
func NewStringSlice ¶
func NewStringSlice(defaults ...string) *StringSlice
NewStringSlice creates a *StringSlice with default values
func (*StringSlice) Get ¶
func (f *StringSlice) Get() interface{}
Get returns the slice of strings set by this flag
func (*StringSlice) Serialized ¶
func (f *StringSlice) Serialized() string
Serialized allows StringSlice to fulfill Serializeder
func (*StringSlice) Set ¶
func (f *StringSlice) Set(value string) error
Set appends the string value to the list of values
func (*StringSlice) String ¶
func (f *StringSlice) String() string
String returns a readable representation of this value (for usage defaults)
func (*StringSlice) Value ¶
func (f *StringSlice) Value() []string
Value returns the slice of strings set by this flag
type StringSliceFlag ¶
type StringSliceFlag struct {
Name string
Aliases []string
Usage string
EnvVars []string
Hidden bool
Value *StringSlice
DefaultText string
}
StringSliceFlag is a flag with type *StringSlice
func (*StringSliceFlag) Apply ¶
func (f *StringSliceFlag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment Ignores errors
func (*StringSliceFlag) ApplyWithError ¶
func (f *StringSliceFlag) ApplyWithError(set *flag.FlagSet) error
ApplyWithError populates the flag given the flag set and environment
func (*StringSliceFlag) Names ¶
func (f *StringSliceFlag) Names() []string
Names returns the names of the flag
func (*StringSliceFlag) String ¶
func (f *StringSliceFlag) String() string
String returns a readable representation of this value (for usage defaults)
type Uint64Flag ¶
type Uint64Flag struct {
Name string
Aliases []string
Usage string
EnvVars []string
Hidden bool
Value uint64
DefaultText string
Destination *uint64
}
Uint64Flag is a flag with type uint64
func (*Uint64Flag) Apply ¶
func (f *Uint64Flag) Apply(set *flag.FlagSet)
Apply populates the flag given the flag set and environment Ignores errors
func (*Uint64Flag) ApplyWithError ¶
func (f *Uint64Flag) ApplyWithError(set *flag.FlagSet) error
ApplyWithError populates the flag given the flag set and environment
func (*Uint64Flag) Names ¶
func (f *Uint64Flag) Names() []string
Names returns the names of the flag
func (*Uint64Flag) String ¶
func (f *Uint64Flag) String() string
String returns a readable representation of this value (for usage defaults)
type UintFlag ¶
type UintFlag struct {
Name string
Aliases []string
Usage string
EnvVars []string
Hidden bool
Value uint
DefaultText string
Destination *uint
}
UintFlag is a flag with type uint
func (*UintFlag) ApplyWithError ¶
ApplyWithError populates the flag given the flag set and environment
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