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.NewApp().Run(os.Args) }
Of course this application does not do much, so let's make this an actual application:
func main() { app := cli.NewApp() app.Name = "greet" app.Usage = "say a greeting" app.Action = func(c *cli.Context) { println("Greetings") } app.Run(os.Args) }
Example ¶
package main import ( "os" "github.com/coreos/etcd-ca/Godeps/_workspace/src/github.com/codegangsta/cli" ) func main() { app := cli.NewApp() app.Name = "todo" app.Usage = "task list on the command line" app.Commands = []cli.Command{ { Name: "add", ShortName: "a", Usage: "add a task to the list", Action: func(c *cli.Context) { println("added task: ", c.Args().First()) }, }, { Name: "complete", ShortName: "c", Usage: "complete a task on the list", Action: func(c *cli.Context) { println("completed task: ", c.Args().First()) }, }, } app.Run(os.Args) }
Output:
Index ¶
- Variables
- func DefaultAppComplete(c *Context)
- func ShowAppHelp(c *Context)
- func ShowCommandCompletions(ctx *Context, command string)
- func ShowCommandHelp(c *Context, command string)
- func ShowCompletions(c *Context)
- func ShowSubcommandHelp(c *Context)
- func ShowVersion(c *Context)
- type App
- type Args
- type BoolFlag
- type BoolTFlag
- type Command
- type Context
- func (c *Context) Args() Args
- func (c *Context) Bool(name string) bool
- func (c *Context) BoolT(name string) bool
- func (c *Context) Duration(name string) time.Duration
- func (c *Context) FlagNames() (names []string)
- func (c *Context) Float64(name string) float64
- func (c *Context) Generic(name string) interface{}
- func (c *Context) GlobalBool(name string) bool
- func (c *Context) GlobalDuration(name string) time.Duration
- func (c *Context) GlobalFlagNames() (names []string)
- func (c *Context) GlobalGeneric(name string) interface{}
- func (c *Context) GlobalInt(name string) int
- func (c *Context) GlobalIntSlice(name string) []int
- func (c *Context) GlobalIsSet(name string) bool
- func (c *Context) GlobalString(name string) string
- func (c *Context) GlobalStringSlice(name string) []string
- func (c *Context) Int(name string) int
- func (c *Context) IntSlice(name string) []int
- func (c *Context) IsSet(name string) bool
- func (c *Context) String(name string) string
- func (c *Context) StringSlice(name string) []string
- type DurationFlag
- type Flag
- type Float64Flag
- type Generic
- type GenericFlag
- type IntFlag
- type IntSlice
- type IntSliceFlag
- type StringFlag
- type StringSlice
- type StringSliceFlag
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var AppHelpTemplate = `` /* 487-byte string literal not displayed */
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 BashCompletionFlag = BoolFlag{
Name: "generate-bash-completion",
}
This flag enables bash-completion for all commands and subcommands
var CommandHelpTemplate = `` /* 242-byte string literal not displayed */
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 HelpFlag = BoolFlag{
Name: "help, h",
Usage: "show help",
}
This flag prints the help for all commands and subcommands Set to the zero value (BoolFlag{}) to disable flag -- keeps subcommand unless HideHelp is set to true)
var HelpPrinter helpPrinter = nil
var SubcommandHelpTemplate = `` /* 286-byte string literal not displayed */
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 VersionFlag = BoolFlag{
Name: "version, v",
Usage: "print the version",
}
This flag prints the version for the application
var VersionPrinter = printVersion
Prints version for the App
Functions ¶
func DefaultAppComplete ¶
func DefaultAppComplete(c *Context)
Prints the list of subcommands as the default app completion method
func ShowAppHelp ¶
func ShowAppHelp(c *Context)
func ShowCommandCompletions ¶
Prints the custom completions for a given command
func ShowCommandHelp ¶
Prints help for the given command
func ShowCompletions ¶
func ShowCompletions(c *Context)
Prints the lists of commands within a given context
Types ¶
type App ¶
type App struct { // The name of the program. Defaults to os.Args[0] Name string // Description of the program. Usage string // Version of the program Version string // List of commands to execute Commands []Command // List of flags to parse Flags []Flag // Boolean to enable bash completion commands EnableBashCompletion bool // Boolean to hide built-in help command HideHelp bool // Boolean to hide built-in version flag HideVersion bool // An action to execute when the bash-completion flag is set BashComplete func(context *Context) // 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 func(context *Context) error // The action to execute when no subcommands are specified Action func(context *Context) // Execute this function if the proper command cannot be found CommandNotFound func(context *Context, command string) // Compilation date Compiled time.Time // Author Author string // Author e-mail Email string // Writer writer to write output to Writer io.Writer }
App is the main structure of a cli application. It is recomended that and app be created with the cli.NewApp() function
Example ¶
package main import ( "fmt" "os" "github.com/coreos/etcd-ca/Godeps/_workspace/src/github.com/codegangsta/cli" ) func main() { // set args for examples sake os.Args = []string{"greet", "--name", "Jeremy"} app := cli.NewApp() app.Name = "greet" app.Flags = []cli.Flag{ cli.StringFlag{Name: "name", Value: "bob", Usage: "a name to say"}, } app.Action = func(c *cli.Context) { fmt.Printf("Hello %v\n", c.String("name")) } app.Run(os.Args) }
Output: Hello Jeremy
func NewApp ¶
func NewApp() *App
Creates a new cli Application with some reasonable defaults for Name, Usage, Version and Action.
func (*App) Run ¶
Entry point to the cli app. Parses the arguments slice and routes to the proper flag/args combination
func (*App) RunAndExitOnError ¶
func (a *App) RunAndExitOnError()
Another entry point to the cli app, takes care of passing arguments and error handling
func (*App) RunAsSubcommand ¶
Invokes the subcommand given the context, parses ctx.Args() to generate command-specific flags
type Command ¶
type Command struct { // The name of the command Name string // short name of the command. Typically one character ShortName string // A short description of the usage of this command Usage string // A longer explanation of how the command works Description string // The function to call when checking for bash command completions BashComplete func(context *Context) // 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 func(context *Context) error // The function to call when this command is invoked Action func(context *Context) // 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 }
Command is a subcommand for a cli.App.
type Context ¶
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 ¶
Creates a new context. For use in when invoking an App or Command action.
func (*Context) Bool ¶
Looks up the value of a local bool flag, returns false if no bool flag exists
func (*Context) BoolT ¶
Looks up the value of a local boolT flag, returns false if no bool flag exists
func (*Context) Duration ¶
Looks up the value of a local time.Duration flag, returns 0 if no time.Duration flag exists
func (*Context) Float64 ¶
Looks up the value of a local float64 flag, returns 0 if no float64 flag exists
func (*Context) Generic ¶
Looks up the value of a local generic flag, returns nil if no generic flag exists
func (*Context) GlobalBool ¶
Looks up the value of a global bool flag, returns false if no bool flag exists
func (*Context) GlobalDuration ¶
Looks up the value of a global time.Duration flag, returns 0 if no time.Duration flag exists
func (*Context) GlobalFlagNames ¶
Returns a slice of global flag names used by the app.
func (*Context) GlobalGeneric ¶
Looks up the value of a global generic flag, returns nil if no generic flag exists
func (*Context) GlobalInt ¶
Looks up the value of a global int flag, returns 0 if no int flag exists
func (*Context) GlobalIntSlice ¶
Looks up the value of a global int slice flag, returns nil if no int slice flag exists
func (*Context) GlobalIsSet ¶
Determines if the global flag was actually set
func (*Context) GlobalString ¶
Looks up the value of a global string flag, returns "" if no string flag exists
func (*Context) GlobalStringSlice ¶
Looks up the value of a global string slice flag, returns nil if no string slice flag exists
func (*Context) IntSlice ¶
Looks up the value of a local int slice flag, returns nil if no int slice flag exists
func (*Context) String ¶
Looks up the value of a local string flag, returns "" if no string flag exists
func (*Context) StringSlice ¶
Looks up the value of a local string slice flag, returns nil if no string slice flag exists
type DurationFlag ¶
func (DurationFlag) Apply ¶
func (f DurationFlag) Apply(set *flag.FlagSet)
func (DurationFlag) String ¶
func (f DurationFlag) String() string
type Flag ¶
type Flag interface { fmt.Stringer // Apply Flag settings to the given flag set Apply(*flag.FlagSet) // contains filtered or unexported methods }
Flag is a common interface related to parsing flags in cli. For more advanced flag parsing techniques, it is recomended that this interface be implemented.
type Float64Flag ¶
func (Float64Flag) Apply ¶
func (f Float64Flag) Apply(set *flag.FlagSet)
func (Float64Flag) String ¶
func (f Float64Flag) String() string
type GenericFlag ¶
GenericFlag is the flag type for types implementing 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
func (GenericFlag) String ¶
func (f GenericFlag) String() string
String returns the string representation of the generic flag to display the help text to the user (uses the String() method of the generic flag to show the value)
type IntSliceFlag ¶
func (IntSliceFlag) Apply ¶
func (f IntSliceFlag) Apply(set *flag.FlagSet)
func (IntSliceFlag) String ¶
func (f IntSliceFlag) String() string
type StringFlag ¶
func (StringFlag) Apply ¶
func (f StringFlag) Apply(set *flag.FlagSet)
func (StringFlag) String ¶
func (f StringFlag) String() string
type StringSlice ¶
type StringSlice []string
func (*StringSlice) Set ¶
func (f *StringSlice) Set(value string) error
func (*StringSlice) String ¶
func (f *StringSlice) String() string
func (*StringSlice) Value ¶
func (f *StringSlice) Value() []string
type StringSliceFlag ¶
type StringSliceFlag struct { Name string Value *StringSlice Usage string EnvVar string }
func (StringSliceFlag) Apply ¶
func (f StringSliceFlag) Apply(set *flag.FlagSet)
func (StringSliceFlag) String ¶
func (f StringSliceFlag) String() string