vaelen / ishell

Library for creating interactive cli applications.

ishell

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

Older version

The current master is not backward compatible with older version. Kindly change your import path to gopkg.in/abiosoft/ishell.v1.

Older version of this library is still available at https://gopkg.in/abiosoft/ishell.v1.

However, you are advised to upgrade.

Usage

import "strings"
import "github.com/abiosoft/ishell"

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.AddCmd(&ishell.Cmd{
        Name: "greet",
        Help: "greet user",
        Func: func(c *ishell.Context) {
            c.Println("Hello", strings.Join(c.Args, " "))
        },
    })

    // start shell
    shell.Start()
}

Execution

Sample Interactive Shell
>>> help

Commands:
  clear      clear the screen
  greet      greet user
  exit       exit the program
  help       display help

>>> greet Someone Somewhere
Hello Someone Somewhere
>>> exit
$

Reading input.

// simulate an authentication
shell.AddCmd(&ishell.Cmd{
    Name: "login",
    Help: "simulate a login",
    Func: func(c *ishell.Context) {
        // disable the '>>>' for cleaner same line input.
        c.ShowPrompt(false)
        defer c.ShowPrompt(true) // yes, revert after login.

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

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

        ... // do something with username and password

        c.Println("Authentication Successful.")
    },
})

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.AddCmd(&ishell.Cmd{
    Name: "multi",
    Help: "input in multiple lines",
    Func: func(c *ishell.Context) {
        c.Println("Input multiple lines and end with semicolon ';'.")
        lines := c.ReadMultiLines(";")
        c.Println("Done reading. You wrote:")
        c.Println(lines)
    },
})

Execution

>>> multi
Input multiple lines and end with semicolon ';'.
>>> 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.Interrupt(func(count int, c *ishell.Context) { ... })

Progress Bar

Determinate

func(c *ishell.Context) {
    c.ProgressBar().Start()
    for i := 0; i < 101; i++ {
        c.ProgressBar().Suffix(fmt.Sprint(" ", i, "%"))
        c.ProgressBar().Progress(i)
        ... // some background computation
    }
    c.ProgressBar().Stop()
}

Output

[==========>         ] 50%

Indeterminate

func(c *ishell.Context) {
    c.ProgressBar().Indeterminate(true)
    c.ProgressBar().Start()
    ... // some background computation
    c.ProgressBar().Stop()
}

Output

[ ====               ]

Custom display using briandowns/spinner.

display := ishell.ProgressDisplayCharSet(spinner.CharSets[11])
func(c *Context) { c.ProgressBar().Display(display) ... }

// or set it globally
ishell.ProgressBar().Display(display)

Durable history.

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

Example

Available here.

go run example/main.go

Supported Platforms

• Linux
• OSX
• Windows [Not tested but should work]

Note

ishell is in active development and can still change significantly.

Roadmap (in no particular order)

• Multiline inputs.
• Command history.
• Customizable tab completion.
• Handle ^C interrupts.
• Subcommands and help texts.
• Scrollable paged output.
• Progress bar.
• Testing, testing, testing.

Contribution

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

License

MIT

Credits

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

Donate

bitcoin:1GTHYEDiy2C7RzXn5nY4wVRaEN2GvLjwZN