Awesome
ishell
ishell is an interactive shell library for creating interactive cli applications.
Usage
import "strings"
import "github.com/abiosoft/ishell/v2"
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, " "))
},
})
// run shell
shell.Run()
}
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) { ... })
Multiple Choice
func(c *ishell.Context) {
choice := c.MultiChoice([]string{
"Golangers",
"Go programmers",
"Gophers",
"Goers",
}, "What are Go programmers called ?")
if choice == 2 {
c.Println("You got it!")
} else {
c.Println("Sorry, you're wrong.")
}
},
Output
What are Go programmers called ?
Golangers
Go programmers
> Gophers
Goers
You got it!
Checklist
func(c *ishell.Context) {
languages := []string{"Python", "Go", "Haskell", "Rust"}
choices := c.Checklist(languages,
"What are your favourite programming languages ?", nil)
out := func() []string { ... } // convert index to language
c.Println("Your choices are", strings.Join(out(), ", "))
}
Output
What are your favourite programming languages ?
Python
ā Go
Haskell
>ā Rust
Your choices are Go, Rust
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")
Non-interactive execution
In some situations it is desired to exit the program directly after executing a single command.
// when started with "exit" as first argument, assume non-interactive execution
if len(os.Args) > 1 && os.Args[1] == "exit" {
shell.Process(os.Args[2:]...)
} else {
// start shell
shell.Run()
}
# Run normally - interactive mode:
$ go run main.go
>>> |
# Run non-interactivelly
$ go run main.go exit greet Someusername
Hello Someusername
Output with Color
You can use fatih/color.
func(c *ishell.Context) {
yellow := color.New(color.FgYellow).SprintFunc()
c.Println(yellow("This line is yellow"))
}
Execution
>>> color
This line is yellow
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
- Multiple choice prompt
- Checklist prompt
- Support for command aliases
- Multiple line progress bars
- Testing, testing, testing
Contribution
- Create an issue to discuss it.
- Send in Pull Request.
License
MIT
Credits
Library | Use |
---|---|
github.com/flynn-archive/go-shlex | splitting input into command and args. |
github.com/chzyer/readline | readline capabilities. |
Donate
bitcoin: 1GTHYEDiy2C7RzXn5nY4wVRaEN2GvLjwZN
paypal: a@abiosoft.com