Minishell

Usage

Prerequisites

Clone the repository to your local machine using the following command in the terminal.

git clone https://github.com/milandekruijf/minishell.git && cd minishell

Compiling

In order to compile the Minishell program, run the following command in the project root directory.

make

*Compiles using the cc compiler with the flags -Wall, -Wextra, and -Werror.

Running

After compiling, the executable minishell will be created in the /out directory. Run the executable to start Minishell.

./out/minishell

You can also just use make run to compile and run the program in one command.

Debugging

In order to debug the program, you must have Valgrind installed. Run the following command in the project root directory to run in debug mode.

make debug

This will recompile everything with the -g3 flag and run the program using valgrind with the following flags: --leak-check=full, --show-leak-kinds=all, and --track-origins=yes

Testing

Run the following command in the project root directory. The tests are located in the /tests directory.

make test

This will recompile everything with the -g3 flag and run the program using valgrind with the following flags: --leak-check=full, --show-leak-kinds=all, and --track-origins=yes

make tests

Linting

In order to lint the project, you must have Norminette installed. Run the following command in the project root directory to lint the project.

make lint

The /tests directory is excluded from linting as it contains test files that do not have to adhere to the 42 coding standards.

Features

Minishell is a lightweight shell program inspired by Bash, designed to provide essential shell functionalities. Below are the key features supported by Minishell.

General

• Prompt Display: A user-friendly prompt that indicates readiness for commands.
• Command History: Navigate through previously executed commands using the up and down arrow keys.
• System Executables: Execute standard system commands like ls, cat, grep, etc.
• Local Executables: Run local executables from the current working directory.

Builtin Commands

Minishell supports the following built-in commands:

• echo: Displays messages, with an option for no trailing newline (-n).
• cd: Changes the current directory using either relative or absolute paths.
• pwd: Outputs the current working directory (no options).
• export: Lists environment variables without options.
• unset: Removes environment variables without options.
• env: Displays the current environment variables without options or arguments.
• exit: Terminates Minishell, with an optional exit status.

Input/Output Management

• Pipes (|): Redirects the output of one command to the input of another, enabling command chaining.
• Redirections:
  • >: Redirects output to a file (overwriting).
  • >>: Redirects output to a file (in append mode).
  • <: Redirects input from a file.
  • <<: Allows for here-document input, prompting the user for input until the specified delimiter is reached. This input is redirected to the command but does not update command history.

Environment Variable Expansion

• Support for environment variable expansion, allowing variables like $USER or custom variables (e.g. $MS_PROMPT) to resolve to their corresponding values.
• The special variable $? returns the exit status of the most recently executed foreground pipeline.

User Keyboard Signals

• User keyboard signals:
  • Ctrl-C: Cancels the current command and displays a new prompt.
  • Ctrl-D: Exits Minishell gracefully.
  • Ctrl-\: Has no effect in the Minishell environment.

Limitations

Minishell does not support the following:

• Escape character (\)
• Command separators (;)
• Logical operators (&&, ||)
• Wildcards (*)

Acknowledgements

• Acutest: A minimal C unit testing framework used for testing individual functions.
• Valgrind: A memory debugging tool used for detecting memory leaks and errors.
• Norminette: Used for linting the project according to the 42 coding standards.
• 42: The educational institution that inspired and supported the development of this project.
• Codam: The partner school of 42 in the Netherlands, where the project was developed.