README
¶
This is yet another library for structuring command-line interfaces. It aims to utilize the Go standard library as much as possible and provide a simpler API than other options.
Goals:
- As lightweight as possible; should leverage the Go standard library for everything it can
- Should enforce consistency. The framework should encourage developers to provide a good user experience, and conform to platform expectations.
- Simple and easy to use. Developers should be able to pick it up with little or no documentation.
Features:
- Easy to create nested subcommands
- Enforced contextual help for every command, subcommand, and flag
- Enforced use of Go contexts for traceability
- Patterns for environment and flag parsing
- Assertions for writing tests
Documentation
¶
Index ¶
- func ExpectError(t *testing.T, err error)
- func ExpectErrorOutput(t *testing.T, stderr bytes.Buffer, err error)
- func ExpectHelp(t *testing.T, stderr bytes.Buffer, cmd Command)
- func ExpectMatch(t *testing.T, stdout bytes.Buffer, pattern string)
- func ExpectOutput(t *testing.T, stdout bytes.Buffer)
- func ExpectSuccess(t *testing.T, err error)
- func Main(mainCmd Command, sys *System) int
- type Action
- type CLI
- type Command
- type HasFlags
- type HasSubcommands
- type NoOpCommand
- type System
- func (s System) Fatal(v ...interface{})
- func (s System) Fatalf(format string, v ...interface{})
- func (s System) Fatalln(v ...interface{})
- func (s System) Getenv(key string) string
- func (s System) Log(a ...interface{})
- func (s System) Logf(format string, a ...interface{})
- func (s System) Print(a ...interface{}) (int, error)
- func (s System) Printf(format string, a ...interface{}) (int, error)
- func (s System) Println(a ...interface{}) (int, error)
- func (s System) Scan(a ...interface{}) (int, error)
- func (s System) Scanf(format string, a ...interface{}) (int, error)
- func (s System) Scanln(a ...interface{}) (int, error)
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func ExpectError ¶
func ExpectSuccess ¶
func Main ¶
Main should be called from a CLI application's `main` function. It should be passed the Command that represents the root of the subcommand tree. Main will parse the command line, determine which subcommand is the intended target, create a FlagSet then execute that subcommand. If no suitable subcommand is found, or if flag parsing fails, it will call the Help method from the most-recently visited subcommand. Main returns the Unix status code which should be returned to the underlying OS
Types ¶
type Action ¶
type Action interface {
// Command is the method that actually performs the command.
Command(context.Context, []string, *System) int
}
Action is an interface for commands that do things other than display information
type CLI ¶
CLI is a map of names to Command implementations. It is used to represent a set of subcommands for a given Command
func (CLI) ListSubcommands ¶
type Command ¶
type Command interface {
// Help is called for a command if the command line fails to parse. It may
// also be manually called in the `Command` method if appropriate.
Help()
}
Command is an interface used to represent a CLI component. Both primary commands and subcommands implement Command
type HasFlags ¶
type HasFlags interface {
// Flags is called before `Command` and is passed a pointer to a flag.FlagSet
// where the Command may define flags to be automatically parsed
Flags(*flag.FlagSet)
}
HasFlags is an interface for commands that use flags
type HasSubcommands ¶
type HasSubcommands interface {
// Subcommands should return a CLI if the command has subcommands
Subcommands() CLI
}
HasSubcommands is an interface for commands that have subcommands
type NoOpCommand ¶
type NoOpCommand struct{}
NoOpCommand is a command that does nothing.
func (NoOpCommand) Help ¶
func (NoOpCommand) Help()
type System ¶
type System struct {
In io.Reader
Out io.Writer
Logger *log.Logger
Environment map[string]string
Arguments []string
}
System is passed to commands as an argument when the command is run. It provides an IO interface for the command to use that can be easily attached to STDIN/STDOUT or to bytes.Buffer for testing
Source Files