wish

A simplified version of the UNIX shell.

Requirements

1. A gcc version which supports C++17. gcc-9 recommended.

sudo apt get install gcc-9 g++-9

1. CMake version 3.20 and above: Download from here and follow the instructions to install
2. googletest for testing. This will be downloaded automatically while building.

Building

It is recommended you use VSCode as your code editor and install the CMake and the CMake tools externsion. The following steps detail how to build the project in CMake.

1. Press Ctrl+Shift+P, type CMake: Set Built Target and set this to ‘all’
2. Press Ctrl+Shift+P, type CMake: Configure and press enter.
3. Finally, press Ctrl+Shift+P, type CMake: Build and press enter.

Usage

After building, the executable wish should appear in your project root directory. You can run this executable in two modes:

Modes

1. Interactive Mode: Simply run ./wish in the project root directory, to start the shell in interactive mode. The shell will process commands one by one based on your input in this mode.
2. Batch Mode: Use this mode if you already have a list of commands that you want to execute written down in another script file. To start in batch mode type ./wish path/to/batch/file in the project root directory.

Inbuilt Commands

The shell provides three commands for managing the shell:

1. cd: Usage: cd "path/to/dest/directory" Like the original UNIX command cd, you can use this to change the current active directory of the shell.
2. exit: Usage: exit To stop the shell’s execution, simply type exit without any arguments into the shell.
3. path Usage: path [path1 | path2 | path3 | ...] Similar to the original UNIX path. Use this to edit the default command path for the shell to look for executables in. If left empty, path is set to NULL and you won’t be able to execute any commands except the shell’s inbuilt commands.

Testing

Press Ctrl+Shift+P, type CMake: Run Tests and press enter.