Custom Shell with Autocomplete and Redirection

Overview

This project is a custom shell implementation in Golang that supports various built-in commands, redirection features, proper string handling, and an intelligent autocomplete system.

Features

1. Built-in Commands

The shell includes support for the following built-in commands:

• pwd - Prints the current working directory.
• cd [directory] - Changes the current directory.
• echo [text] - Prints the given text, handling quotes and escape sequences correctly.
• exit - Exits the shell.

2. Input Handling

• Proper handling of strings, quotes, and escape sequences.
• Allows execution of both built-in and external commands.

3. Redirection Support

The shell supports all common output and error redirections:

• Overwrite mode:
  • command > file (Redirect stdout to a file, overwriting if it exists.)
  • command 2> file (Redirect stderr to a file, overwriting if it exists.)
• Append mode:
  • command >> file (Append stdout to a file.)
  • command 2>> file (Append stderr to a file.)
• Both stdout and stderr:
  • command &> file (Redirect both stdout and stderr to a file.)
  • command &>> file (Append both stdout and stderr to a file.)

4. Autocomplete Feature

The shell implements an autocomplete system for command names when the user presses the Tab key.

• If multiple commands match the given prefix, it completes to the longest common prefix.
• If a single unique match is found, it completes the command automatically.
• If the match is the longest possible valid command, a space is added after it.

Example:

$ xyz_<TAB>        # Completes to xyz_foo
$ xyz_foo_<TAB>    # Completes to xyz_foo_bar
$ xyz_foo_bar_<TAB> # Completes to xyz_foo_bar_baz (with a space at the end)

5. Executable Handling

• The shell searches for executables in the system PATH.
• Supports both built-in commands and external programs.
• Implements longestCommonPrefix logic for intelligent tab completion.

Installation and Usage

1. Clone the Repository

git clone https://github.com/DebdipWritesCode/shell-golang.git
cd shell-golang
cd app

2. Build the Shell

go build -o my_shell main.go

3. Run the Shell

./my_shell

Future Enhancements

• Implement piping (|) between commands.
• Support for background processes (&).
• Enhanced command history and navigation.

Contributors

• Debdip Mukherjee (@DebdipWritesCode)

License

This project is licensed under the MIT License.