Name: cli
Owner: Netflix-Skunkworks
Description: A simple, fast, and fun package for building command line apps in Go
Created: 2018-02-23 23:41:25.0
Updated: 2018-02-23 23:41:27.0
Pushed: 2018-02-24 05:47:01.0
Size: 1175
Language: Go
GitHub Committers
User | Most Recent Commit | # Commits |
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Other Committers
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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.
v2
branchv1
releasesCommand 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!
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:
get github.com/urfave/cli
Make sure your PATH
includes the $GOPATH/bin
directory so your commands can
be easily used:
rt PATH=$PATH:$GOPATH/bin
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
.
v2
branchWarning: 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
:
get gopkg.in/urfave/cli.v2
go
rt (
opkg.in/urfave/cli.v2" // imports as package "cli"
v1
releasesSimilarly 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.:
get gopkg.in/urfave/cli.v1
go
rt (
opkg.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).
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()
.
age main
rt (
s"
ithub.com/urfave/cli"
main() {
i.NewApp().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:
age main
rt (
mt"
s"
ithub.com/urfave/cli"
main() {
p := cli.NewApp()
p.Name = "boom"
p.Usage = "make an explosive entrance"
p.Action = func(c *cli.Context) error {
fmt.Println("boom! I say!")
return nil
p.Run(os.Args)
Running this already gives you a ton of functionality, plus support for things like subcommands and flags, which are covered below.
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:
age main
rt (
mt"
s"
ithub.com/urfave/cli"
main() {
p := cli.NewApp()
p.Name = "greet"
p.Usage = "fight the loneliness!"
p.Action = func(c *cli.Context) error {
fmt.Println("Hello friend!")
return nil
p.Run(os.Args)
Install our command to the $GOPATH/bin
directory:
install
Finally run our new command:
eet
o friend!
cli also generates neat help text:
eet help
:
greet - fight the loneliness!
E:
greet [global options] command [command options] [arguments...]
ION:
0.0.0
ANDS:
help, h Shows a list of commands or help for one command
AL OPTIONS
--version Shows version information
You can lookup arguments by calling the Args
function on cli.Context
, e.g.:
age main
rt (
mt"
s"
ithub.com/urfave/cli"
main() {
p := cli.NewApp()
p.Action = func(c *cli.Context) error {
fmt.Printf("Hello %q", c.Args().Get(0))
return nil
p.Run(os.Args)
Setting and querying flags is simple.
age main
rt (
mt"
s"
ithub.com/urfave/cli"
main() {
p := cli.NewApp()
p.Flags = []cli.Flag {
cli.StringFlag{
Name: "lang",
Value: "english",
Usage: "language for the greeting",
},
p.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
p.Run(os.Args)
You can also set a destination variable for a flag, to which the content will be scanned.
age main
rt (
s"
mt"
ithub.com/urfave/cli"
main() {
r language string
p := cli.NewApp()
p.Flags = []cli.Flag {
cli.StringFlag{
Name: "lang",
Value: "english",
Usage: "language for the greeting",
Destination: &language,
},
p.Action = func(c *cli.Context) error {
name := "someone"
if c.NArg() > 0 {
name = c.Args()[0]
}
if language == "spanish" {
fmt.Println("Hola", name)
} else {
fmt.Println("Hello", name)
}
return nil
p.Run(os.Args)
See full list of flags at http://godoc.org/github.com/urfave/cli
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:
age main
rt (
s"
ithub.com/urfave/cli"
main() {
p := cli.NewApp()
p.Flags = []cli.Flag{
cli.StringFlag{
Name: "config, c",
Usage: "Load configuration from `FILE`",
},
p.Run(os.Args)
Will result in help output like:
nfig FILE, -c FILE Load configuration from FILE
Note that only the first placeholder is used. Subsequent back-quoted words will be left as-is.
You can set alternate (or short) names for flags by providing a comma-delimited
list for the Name
. e.g.
age main
rt (
s"
ithub.com/urfave/cli"
main() {
p := cli.NewApp()
p.Flags = []cli.Flag {
cli.StringFlag{
Name: "lang, l",
Value: "english",
Usage: "language for the greeting",
},
p.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.
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:
age main
rt (
s"
ort"
ithub.com/urfave/cli"
main() {
p := cli.NewApp()
p.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`",
},
p.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
},
},
rt.Sort(cli.FlagsByName(app.Flags))
rt.Sort(cli.CommandsByName(app.Commands))
p.Run(os.Args)
Will result in help output like:
nfig FILE, -c FILE Load configuration from FILE
ng value, -l value Language for the greeting (default: "english")
You can also have the default value set from the environment via EnvVar
. e.g.
age main
rt (
s"
ithub.com/urfave/cli"
main() {
p := cli.NewApp()
p.Flags = []cli.Flag {
cli.StringFlag{
Name: "lang, l",
Value: "english",
Usage: "language for the greeting",
EnvVar: "APP_LANG",
},
p.Run(os.Args)
The EnvVar
may also be given as a comma-delimited “cascade”, where the first
environment variable that resolves is used as the default.
age main
rt (
s"
ithub.com/urfave/cli"
main() {
p := cli.NewApp()
p.Flags = []cli.Flag {
cli.StringFlag{
Name: "lang, l",
Value: "english",
Usage: "language for the greeting",
EnvVar: "LEGACY_COMPAT_LANG,APP_LANG,LANG",
},
p.Run(os.Args)
You can also have the default value set from file via FilePath
. e.g.
age main
rt (
s"
ithub.com/urfave/cli"
main() {
p := cli.NewApp()
p.Flags = []cli.Flag {
cli.StringFlag{
Name: "password, p",
Usage: "password for the mysql database",
FilePath: "/etc/mysql/password",
},
p.Run(os.Args)
Note that default values set from file (e.g. FilePath
) take precedence over
default values set from the enviornment (e.g. EnvVar
).
There is a separate package altsrc that adds support for getting flag values from other file input sources.
Currently supported input source formats:
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:
tsrc.NewIntFlag(cli.IntFlag{Name: "test"})
Initialization must also occur for these flags. Below is an example initializing getting data from a yaml file below.
mmand.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:
age notmain
rt (
mt"
s"
ithub.com/urfave/cli"
ithub.com/urfave/cli/altsrc"
main() {
p := cli.NewApp()
ags := []cli.Flag{
altsrc.NewIntFlag(cli.IntFlag{Name: "test"}),
cli.StringFlag{Name: "load"},
p.Action = func(c *cli.Context) error {
fmt.Println("yaml ist rad")
return nil
p.Before = altsrc.InitInputSourceWithContext(flags, altsrc.NewYamlSourceFromFlagFunc("load"))
p.Flags = flags
p.Run(os.Args)
The precedence for flag value sources is as follows (highest to lowest):
Subcommands can be defined for a more git-like command line app.
age main
rt (
mt"
s"
ithub.com/urfave/cli"
main() {
p := cli.NewApp()
p.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
},
},
},
},
p.Run(os.Args)
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.
age main
rt (
s"
ithub.com/urfave/cli"
main() {
p := cli.NewApp()
p.Commands = []cli.Command{
{
Name: "noop",
},
{
Name: "add",
Category: "Template actions",
},
{
Name: "remove",
Category: "Template actions",
},
p.Run(os.Args)
Will include:
ANDS:
noop
mplate actions:
add
remove
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.:
age main
rt (
s"
ithub.com/urfave/cli"
main() {
p := cli.NewApp()
p.Flags = []cli.Flag{
cli.BoolTFlag{
Name: "ginger-crouton",
Usage: "is it in the soup?",
},
p.Action = func(ctx *cli.Context) error {
if !ctx.Bool("ginger-crouton") {
return cli.NewExitError("it is not in the soup", 86)
}
return nil
p.Run(os.Args)
You can enable completion commands by setting the EnableBashCompletion
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.
age main
rt (
mt"
s"
ithub.com/urfave/cli"
main() {
sks := []string{"cook", "clean", "laundry", "eat", "sleep", "code"}
p := cli.NewApp()
p.EnableBashCompletion = true
p.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
},
BashComplete: func(c *cli.Context) {
// This will complete if no args are passed
if c.NArg() > 0 {
return
}
for _, t := range tasks {
fmt.Println(t)
}
},
},
p.Run(os.Args)
Source the autocomplete/bash_autocomplete
file in your .bashrc
file while
setting the PROG
variable to the name of your program:
PROG=myprogram source /.../cli/autocomplete/bash_autocomplete
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.
cp src/bash_autocomplete /etc/bash_completion.d/<myprogram>
ce /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).
The default bash completion flag (--generate-bash-completion
) is defined as
cli.BashCompletionFlag
, and may be redefined if desired, e.g.:
age main
rt (
s"
ithub.com/urfave/cli"
main() {
i.BashCompletionFlag = cli.BoolFlag{
Name: "compgen",
Hidden: true,
p := cli.NewApp()
p.EnableBashCompletion = true
p.Commands = []cli.Command{
{
Name: "wat",
},
p.Run(os.Args)
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.
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.:
age main
rt (
mt"
o"
s"
ithub.com/urfave/cli"
main() {
EXAMPLE: Append to an existing template
i.AppHelpTemplate = fmt.Sprintf(`%s
ITE: http://awesometown.example.com
ORT: support@awesometown.example.com
li.AppHelpTemplate)
EXAMPLE: Override a template
i.AppHelpTemplate = `NAME:
{.Name}} - {{.Usage}}
E:
{.HelpName}} {{if .VisibleFlags}}[global options]{{end}}{{if .Commands}} command [command options]{{end}} {{if .ArgsUsage}}{{.ArgsUsage}}{{else}}[arguments...]{{end}}
{if len .Authors}}
OR:
{range .Authors}}{{ . }}{{end}}
{end}}{{if .Commands}}
ANDS:
nge .Commands}}{{if not .HideHelp}} {{join .Names ", "}}{{ "\t"}}{{.Usage}}{{ "\n" }}{{end}}{{end}}{{end}}{{if .VisibleFlags}}
AL OPTIONS:
{range .VisibleFlags}}{{.}}
{end}}{{end}}{{if .Copyright }}
RIGHT:
{.Copyright}}
{end}}{{if .Version}}
ION:
{.Version}}
{end}}
EXAMPLE: Replace the `HelpPrinter` func
i.HelpPrinter = func(w io.Writer, templ string, data interface{}) {
fmt.Println("Ha HA. I pwnd the help!!1")
i.NewApp().Run(os.Args)
The default flag may be customized to something other than -h/--help
by
setting cli.HelpFlag
, e.g.:
age main
rt (
s"
ithub.com/urfave/cli"
main() {
i.HelpFlag = cli.BoolFlag{
Name: "halp, haaaaalp",
Usage: "HALP",
EnvVar: "SHOW_HALP,HALPPLZ",
i.NewApp().Run(os.Args)
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.
The default flag may be customized to something other than -v/--version
by
setting cli.VersionFlag
, e.g.:
age main
rt (
s"
ithub.com/urfave/cli"
main() {
i.VersionFlag = cli.BoolFlag{
Name: "print-version, V",
Usage: "print only the version",
p := cli.NewApp()
p.Name = "partay"
p.Version = "19.99.0"
p.Run(os.Args)
Alternatively, the version printer at cli.VersionPrinter
may be overridden, e.g.:
age main
rt (
mt"
s"
ithub.com/urfave/cli"
(
vision = "fafafaf"
main() {
i.VersionPrinter = func(c *cli.Context) {
fmt.Printf("version=%s revision=%s\n", c.App.Version, Revision)
p := cli.NewApp()
p.Name = "partay"
p.Version = "19.99.0"
p.Run(os.Args)
Notice: This is a contrived (functioning) example meant strictly for API demonstration purposes. Use of one's imagination is encouraged.
age main
rt (
rrors"
lag"
mt"
o"
o/ioutil"
s"
ime"
ithub.com/urfave/cli"
init() {
i.AppHelpTemplate += "\nCUSTOMIZED: you bet ur muffins\n"
i.CommandHelpTemplate += "\nYMMV\n"
i.SubcommandHelpTemplate += "\nor something\n"
i.HelpFlag = cli.BoolFlag{Name: "halp"}
i.BashCompletionFlag = cli.BoolFlag{Name: "compgen", Hidden: true}
i.VersionFlag = cli.BoolFlag{Name: "print-version, V"}
i.HelpPrinter = func(w io.Writer, templ string, data interface{}) {
fmt.Fprintf(w, "best of luck to you\n")
i.VersionPrinter = func(c *cli.Context) {
fmt.Fprintf(c.App.Writer, "version=%s\n", c.App.Version)
i.OsExiter = func(c int) {
fmt.Fprintf(cli.ErrWriter, "refusing to exit %d\n", c)
i.ErrWriter = ioutil.Discard
i.FlagStringer = func(fl cli.Flag) string {
return fmt.Sprintf("\t\t%s", fl.GetName())
hexWriter struct{}
(w *hexWriter) Write(p []byte) (int, error) {
r _, b := range p {
fmt.Printf("%x", b)
t.Printf("\n")
turn len(p), nil
genericType struct{
string
(g *genericType) Set(value string) error {
s = value
turn nil
(g *genericType) String() string {
turn g.s
main() {
p := cli.NewApp()
p.Name = "k?n?tr?v"
p.Version = "19.99.0"
p.Compiled = time.Now()
p.Authors = []cli.Author{
cli.Author{
Name: "Example Human",
Email: "human@example.com",
},
p.Copyright = "(c) 1999 Serious Enterprise"
p.HelpName = "contrive"
p.Usage = "demonstrate available API"
p.UsageText = "contrive - demonstrating the available API"
p.ArgsUsage = "[args and such]"
p.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, forevvarr"},
},
Subcommands: cli.Commands{
cli.Command{
Name: "wop",
Action: wopAction,
},
},
SkipFlagParsing: false,
HideHelp: false,
Hidden: false,
HelpName: "doo!",
BashComplete: 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
},
},
p.Flags = []cli.Flag{
cli.BoolFlag{Name: "fancy"},
cli.BoolTFlag{Name: "fancier"},
cli.DurationFlag{Name: "howlong, 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, d"},
cli.StringSliceFlag{Name: "names, N"},
cli.UintFlag{Name: "age"},
cli.Uint64Flag{Name: "bigage"},
p.EnableBashCompletion = true
p.HideHelp = false
p.HideVersion = false
p.BashComplete = func(c *cli.Context) {
fmt.Fprintf(c.App.Writer, "lipstick\nkiss\nme\nlipstick\nringo\n")
p.Before = func(c *cli.Context) error {
fmt.Fprintf(c.App.Writer, "HEEEERE GOES\n")
return nil
p.After = func(c *cli.Context) error {
fmt.Fprintf(c.App.Writer, "Phew!\n")
return nil
p.CommandNotFound = func(c *cli.Context, command string) {
fmt.Fprintf(c.App.Writer, "Thar be no %q here.\n", command)
p.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
p.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() {
fmt.Fprintf(c.App.Writer, "%s\n", category.Name)
fmt.Fprintf(c.App.Writer, "%#v\n", category.Commands)
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 len(c.Args()) > 0 {
fmt.Printf("%#v\n", c.Args()[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.BoolT("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.GlobalBool("global-nope"))
fmt.Printf("%#v\n", nc.GlobalBoolT("global-nerp"))
fmt.Printf("%#v\n", nc.GlobalDuration("global-howlong"))
fmt.Printf("%#v\n", nc.GlobalFloat64("global-hay"))
fmt.Printf("%#v\n", nc.GlobalGeneric("global-bloop"))
fmt.Printf("%#v\n", nc.GlobalInt("global-bips"))
fmt.Printf("%#v\n", nc.GlobalIntSlice("global-blups"))
fmt.Printf("%#v\n", nc.GlobalString("global-snurt"))
fmt.Printf("%#v\n", nc.GlobalStringSlice("global-snurkles"))
fmt.Printf("%#v\n", nc.FlagNames())
fmt.Printf("%#v\n", nc.GlobalFlagNames())
fmt.Printf("%#v\n", nc.GlobalIsSet("wat"))
fmt.Printf("%#v\n", nc.GlobalSet("wat", "nope"))
fmt.Printf("%#v\n", nc.NArg())
fmt.Printf("%#v\n", nc.NumFlags())
fmt.Printf("%#v\n", nc.Parent())
nc.Set("wat", "also-nope")
ec := cli.NewExitError("ohwell", 86)
fmt.Fprintf(c.App.Writer, "%d", ec.ExitCode())
fmt.Printf("made it!\n")
return ec
os.Getenv("HEXY") != "" {
app.Writer = &hexWriter{}
app.ErrWriter = &hexWriter{}
p.Metadata = map[string]interface{}{
"layers": "many",
"explicable": false,
"whatever-values": 19.99,
p.Run(os.Args)
wopAction(c *cli.Context) error {
t.Fprintf(c.App.Writer, ":wave: over here, eh\n")
turn nil
Traditional use of boolean options using their shortnames look like this:
d foobar -s -o
Suppose you want users to be able to combine your bool options with their shortname. This can be done using the UseShortOptionHandling bool in your commands. Suppose your program has a two bool flags such as serve and option with the short options of -o and -s respectively. With UseShortOptionHandling set to true, a user can use a syntax like:
d foobar -so
If you enable the *UseShortOptionHandling, then you must not use any flags that have a single leading - or this will result in failures. For example, -option can no longer be used. Flags with two leading dashes (such as –options) are still valid.