Livl Shell

An Intermediate Reimplementation of the Bash Shell in C

Check out the project report to learn more about our implementation.

Table of Contents

• 📦 Prerequisites
• 🚀 Quick start
• 📚 Makefile Guide
• 📁 Project structure
• 📝 List of insane livl-bash commands
  • Basic Commands
  • Input/Output Redirection
  • Pipelines
  • Command Sequencing
  • Batch Mode
  • Background Execution
  • History
  • Alias
• Working with the documentation
  • 📖 Use the livl-shell man command
  • 📜 Doxygen documentation
    • 📦 Prerequisites of Doxygen
    • 🚀 Generate the Doxygen documentation
  • 🧪 GCOV test coverage
    • 📦 Prerequisites of gcov
    • 🚀 Generate the coverage report
• 🛠️ Pipelines
  • 1. C-Make Pipeline
  • 2. Static Pipeline
• 🧍🏽Project team

📦 Prerequisites

This project is developed in C language, so you need to have a C compiler installed on your machine to build it. It would be better to run it on a Linux distribution, but it has also been tested on macOS. It is possible to run it on Windows with the WSL (Windows Subsystem for Linux).

• gcc : sudo apt install gcc
• make: sudo apt install make

To install the WSL on Windows, follow this tutorial.

🚀 Quick start

Follow these steps to quickly get started:

1. Compile the Project: Run the make command. This will compile the project and create an executable file called livl-shell in the bin folder.

2. Run the Executable: You can run the executable by using the command ./bin/livl-shell or make run.

😀 Insane feature: You can run the executable in batch mode by using the command ./bin/livl-shell -c "ls -l".

3. Clean the Project: Use the make clean command to clean the project.

💡 Tip: The command make run will compile and immediately run the executable. It is equivalent to running make && ./bin/livl-shell.

📚 Makefile Guide

The project uses a Makefile for managing build tasks. Here are some of the available targets:

• all: Compile the project.
• run: Run the executable.
• doc: Generate documentation using Doxygen.
• gcov: Generate code coverage data using gcov and lcov.
• package: Package the project into a tar.gz file.
• clean: Remove all object files.
• clean-gcov: Remove all gcov-related files.
• mrproper: Perform a deep clean of the project.
• clear: Clear the console.

You can use the make help command to display a brief description of each target.

📁 Project structure

The project is structured as follows:

livl-shell/
├── bin/ # Contains the compiled binary
│   └── livl-shell # Executable
├── doc/ # Contains the Doxygen documentation
│   └── html/
│       └── index.html
├── gcov/ # Contains the coverage report
│   └── report/
│       └── index.html
├── include/ # Contains the header files
│   └── file.h
|   └── ...
├── src/ # Contains the source files
│   └── file.c
|   └── ...
├── livl-shell.1 # Manual of the livl-shell
├── index.html # Static Livl Shell website
├── history.txt # History of your commands
├── aliases.txt # List of aliases
└── Makefile # Makefile

📝 List of Insane livl-bash features

💡 The livl-shell is limited to run a maximum of 3 commands in a row.

Basic Commands

• ls: Lists the files in the current directory.
• cd: Changes the current directory.
• pwd: Prints the current directory.
• echo: Displays a line of text.

Input/Output Redirection

• ls -l > output.txt: Redirects the output of a command to a file.
• pwd >> output.txt: Appends the output of a command to a file.
• wc -l < output.txt: Counts the number of lines in the file.
• cat << EOF : let the user enter text until he types 'EOF' (You can change EOF by whatever you want). The text is then displayed on the screen thanks to the cat command.

Pipelines

• ls -l | grep '.txt': Redirects the output of a command to another command. You can use single, double, or no quotes.

Command Sequencing

• sleep 4 && echo "Second command executed": Executes a command after another one.
• false && echo "This won't be executed": Executes a command after another one only if the first one succeeded.
• false || echo "This will be executed": Executes a command after another one only if the first one failed.
• echo "Command 1"; sleep 3; echo "Command 2"; ls -l: Executes multiple commands regardless of the success of the previous ones. The ls -l won't be executed because the shell is limited to run a maximum of 3 commands in a row.

Batch Mode

⚠️ The command should be enclosed in quotes to ensure it is passed as a single argument

• ./livl-shell -c "ls -l|grep txt && echo heyyy": Executes a list of commands from the command line.
• ./livl-shell --command "echo livl": Executes a list of commands from the command line.

Background Execution

• sleep 3 & echo hey: Executes a command in the background (the shell will not wait for the command to finish) and it will show you the job id of the background process (ex: [1] 1234).
• pwd: Running this command will display the job id of the background process terminated (ex: [1] done sleep 3).

History

The livl-shell has an ex history feature that allows you to view the history of your commands.

Experimental: Use up / down and left / right arrows. To be able to use this feature, you need to go to the branch feat/history-navigation. This feature is not available on the master branch because some issues have been detected when using the left / right arrows to move the cursor in the command line and the up / down arrows to navigate through the history. But feel free to contribute to this branch if you want to fix this issue. 😀

The history is saved in the history.txt file.

Alias

Livl-shell provide a basic alias support. Alias can be defined only by editing the aliases.txt file. The syntax is the following:

alias_name="command"

Note that you can't use alias inside alias.

For example, if you want to create an alias for the ls -l command, you can add the following line to the alias.txt file:

ll="ls -l"

Then, you can run the ll command to execute the ls -l command.

You can input arguments with your alias, as well as use pipes and redirections. For example, if you input ll -m it will be interpreted as ls -l -m.

Command sequencing, pipes & redirections are not supported in aliases. Alias can only work for a single command.

Working with the documentation

📖 Use the livl-shell man command

To edit the man you can download a TROFF Syntax Highlighter for Visual Studio Code.

• The man livl-shell manual is located in the livl-shell.1 file
• To view the manual, run : man ./livl-shell.1

📜 Doxygen documentation

❓ Doxygen is a documentation generator, a tool for writing software reference documentation.

📦 Prerequisites of Doxygen

• Download doxygen : sudo apt install doxygen

🚀 Generate the Doxygen documentation

• Run make doc to generate the documentation
• To view the documentation, open the index.html file in the doc/html/ folder.

🧪 GCOV test coverage

❓ GCOV is a test coverage program. It helps you determine how much of your source code is being tested by your test suite. It is a useful tool for finding untested code.

📦 Prerequisites of gcov

• Download gcov : sudo apt install gcov
• Download lcov : sudo apt install lcov

🚀 Generate the coverage report

• Run make gcov to generate the coverage report
• To exit the coverage report, press exit two times (one for the shell and one for the coverage report)
• To view the coverage report, open the index.html file in the gcov/report/ folder or run gcovr -r .
• Run make clean-gcov to clean the gcov folder

🛠️ Pipelines

Our pipelines are configured to be triggered on each push and pull request event on the master branch. We have two main pipelines:

1. C-Make Pipeline

The c-make pipeline compiles the project using the make command.

2. Static Pipeline

The static pipeline hosts the static website on GitHub Pages at the root of the repository. This allows access to the Doxygen documentation and the Coverage report at the following address: https://livl-corporation.github.io/livl-shell/

🧍🏽Project team

The Livl team is composed of two members from the CNAM of Strasbourg:

@FranckG28	@jvondermarck
Franck Gutmann	Julien Von Der Marck