readline

Readline is a pure go(golang) implementation for GNU-Readline kind library

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PSReadLine

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A bash inspired readline implementation for PowerShell

Quick Overview

chzyer/readline is a pure Go implementation of the GNU readline library. It provides a set of functions for reading lines of text from user input with line editing and history capabilities, making it useful for building interactive command-line interfaces in Go applications.

Pros

Pure Go implementation, no C dependencies
Supports various terminal key bindings and editing features
Provides history management and search functionality
Cross-platform compatibility (Windows, macOS, Linux)

Cons

May not have all features of the original GNU readline library
Limited documentation and examples compared to more established libraries
Potential performance differences compared to C-based implementations
Less active development and maintenance compared to some alternatives

Code Examples

Basic line reading:

import "github.com/chzyer/readline"

rl, err := readline.New("> ")
if err != nil {
    panic(err)
}
defer rl.Close()

line, err := rl.Readline()
if err != nil {
    panic(err)
}
fmt.Println("You entered:", line)

Using custom completer:

completer := readline.NewPrefixCompleter(
    readline.PcItem("say",
        readline.PcItem("hello"),
        readline.PcItem("bye"),
    ),
    readline.PcItem("help"),
)

rl, err := readline.NewEx(&readline.Config{
    Prompt:       "> ",
    AutoComplete: completer,
})

Reading with a password prompt:

rl, err := readline.New("> ")
if err != nil {
    panic(err)
}
defer rl.Close()

password, err := rl.ReadPassword("Enter password: ")
if err != nil {
    panic(err)
}
fmt.Println("Password entered:", string(password))

Getting Started

To use chzyer/readline in your Go project, follow these steps:

Install the package:
```
go get -u github.com/chzyer/readline
```
Import the package in your Go code:
```
import "github.com/chzyer/readline"
```

Create a new readline instance and use it to read input:

rl, err := readline.New("> ")
if err != nil {
    panic(err)
}
defer rl.Close()

for {
    line, err := rl.Readline()
    if err != nil { // io.EOF, readline.ErrInterrupt
        break
    }
    fmt.Println("Line:", line)
}

This basic setup allows you to start reading lines with a simple prompt. You can customize the behavior by providing additional configuration options when creating the readline instance.

Competitor Comparisons

linenoise

3,747

A small self-contained alternative to readline and libedit

Pros of linenoise

Lightweight and simple implementation (single C file)
No external dependencies, easy to integrate
Cross-platform support (Unix, Windows, Android)

Cons of linenoise

Limited advanced features compared to readline
Less extensive documentation and community support
Fewer customization options for complex use cases

Code comparison

linenoise:

char *line = linenoise("hello> ");
if (line != NULL) {
    printf("You wrote: %s\n", line);
    linenoiseFree(line);
}

readline:

rl, err := readline.New("> ")
if err != nil {
    panic(err)
}
defer rl.Close()
line, err := rl.Readline()
if err != nil {
    panic(err)
}
fmt.Printf("Line: %s\n", line)

Key differences

linenoise is written in C, while readline is written in Go
readline offers more advanced features like history search and custom completion
linenoise focuses on simplicity and small footprint, while readline provides a more feature-rich experience

Use cases

linenoise: Ideal for embedded systems, simple CLI tools, or projects requiring minimal dependencies
readline: Better suited for complex interactive shells, applications needing advanced line editing features, or Go-based projects

python-prompt-toolkit

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Library for building powerful interactive command line applications in Python

Pros of python-prompt-toolkit

More feature-rich with advanced functionality like syntax highlighting and multi-line editing
Pure Python implementation, making it easier to install and use across different platforms
Actively maintained with regular updates and improvements

Cons of python-prompt-toolkit

Potentially slower performance compared to readline's C implementation
Steeper learning curve due to more complex API and additional features
Larger codebase and dependencies, which may increase project size

Code Comparison

python-prompt-toolkit:

from prompt_toolkit import prompt

user_input = prompt('Enter your name: ')
print(f"Hello, {user_input}!")

readline:

import readline

readline.parse_and_bind('tab: complete')
user_input = input('Enter your name: ')
print(f"Hello, {user_input}!")

Both libraries provide input functionality, but python-prompt-toolkit offers more advanced features out of the box, while readline focuses on basic line editing and history. python-prompt-toolkit's approach is more Pythonic and user-friendly, whereas readline requires additional configuration for features like tab completion.

PSReadLine

3,694

A bash inspired readline implementation for PowerShell

Pros of PSReadLine

More comprehensive feature set, including syntax highlighting and multi-line editing
Specifically designed for PowerShell, offering better integration and PowerShell-specific functionality
Actively maintained with frequent updates and improvements

Cons of PSReadLine

Limited to PowerShell environment, not as versatile for other platforms or languages
Potentially more complex to set up and configure compared to readline

Code Comparison

PSReadLine:

Set-PSReadLineOption -PredictionSource History
Set-PSReadLineOption -HistorySearchCursorMovesToEnd
Set-PSReadLineKeyHandler -Key UpArrow -Function HistorySearchBackward

readline:

rl, err := readline.New("> ")
if err != nil {
    panic(err)
}
defer rl.Close()

Key Differences

PSReadLine is tailored for PowerShell, while readline is a more general-purpose Go library
PSReadLine offers more advanced features like predictive IntelliSense and custom key bindings
readline provides a simpler, lightweight solution for basic line editing functionality

Use Cases

PSReadLine: Ideal for PowerShell users and developers looking for enhanced command-line experience
readline: Suitable for Go projects requiring basic line editing capabilities across different platforms