pkorotkov / ishell

interactive shell library for creating interactive cli applications.

ishell

ishell is an interactive shell library for creating interactive cli applications.

Usage

func main(){
    // create new shell.
    // by default, new shell includes 'exit', 'help' and 'clear' commands.
    shell := ishell.New()

	// display welcome info.
	shell.Println("Sample Interactive Shell")

	// register a function for "greet" command.
    shell.Register("greet", func(args ...string) (string, error) {
        name := "Stranger"
        if len(args) > 0 {
            name = strings.Join(args, " ")
        }
		return "Hello "+name, nil
	})

	// start shell
	shell.Start()
}

Execution

Sample Interactive Shell
>>> help
Commands:
exit help greet
>>> greet Someone Somewhere
Hello Someone Somewhere
>>> exit
$

Reading input.

// simulate an authentication
shell.Register("login", func(args ...string) (string, error) {
	// disable the '>>>' for cleaner same line input.
	shell.ShowPrompt(false)
	defer shell.ShowPrompt(true) // yes, revert after login.

    // get username
	shell.Print("Username: ")
	username := shell.ReadLine()

    // get password.
	shell.Print("Password: ")
	password := shell.ReadPassword()

	... // do something with username and password

    return "Authentication Successful.", nil
})

Execution

>>> login
Username: someusername
Password:
Authentication Successful.

Multiline input.

Builtin support for multiple lines.

>>> This is \
... multi line

>>> Cool that << EOF
... everything here goes
... as a single argument. 
... EOF

User defined

shell.Register("multi", func(args ...string) (string, error) {
	shell.Println("Input some lines:")
	// read until a semicolon ';' is found
	// use shell.ReadMultiLinesFunc for more control.
	lines := shell.ReadMultiLines(";")
	shell.Println("You wrote:")
	return lines, nil
})

Execution

>>> multi
Input some lines:
>>> this is user defined 
... multiline input;
You wrote:
this is user defined
multiline input;

Keyboard interrupt.

Builtin interrupt handler.

>>> ^C
Input Ctrl-C once more to exit
>>> ^C
Interrupted
exit status 1

Custom

shell.RegisterInterrupt(func(args ...string) (string, error) { ... })

Durable history.

// Read and write history to $HOME/.ishell_history
shell.SetHomeHistoryPath(".ishell_history")

Check example code for more.

Supported Platforms

• Linux
• OSX
• Windows

Note

ishell is in active development and can still change significantly.

Roadmap (in no particular order)

• Support multiline inputs.
• Command history.
• Tab completion.
• Handle ^C interrupts.
• Subcommands and help texts.
• Coloured outputs.
• Testing, testing, testing.

Contribution

1. Create an issue to discuss it.
2. Send in Pull Request.

License

MIT

Credits

Library	Use
github.com/flynn/go-shlex	splitting input into command and args.
gopkg.in/readline.v1	history, tab completion and reading passwords.