Minishell

Minishell is a simple shell program written in C, providing a basic command-line interface for users to interact with their operating system. It supports various built-in commands and allows users to execute external programs as well.

Features

• Command Execution: Execute shell commands and external programs.
• Argument Expansion Expands environment variables such s $PATH, single quoted argument to literal string, double quoted argument to environment variable expanded string.
• Built-in Commands: Supports a variety of built-in commands, including cd, echo, env, exit, export, pwd, and unset.
• Command Line Editing: Utilizes readline library for command line editing and history functionality.
• Signal Handling: Handles signals include Ctrl+C [SIGINT] and Ctrl+\ [SIGQUIT].
• Input/Output Redirection: Supports input/output redirection with <: input redirect, >: output redirect, >>: output redirect append, <<: heredoc.
• Pipes: Allows piping of commands using | operator.
• Working history Use arrow ↑ and ↓ to browse through history and retry commands.

Installation

1. Clone the repository:

   git clone https://github.com/theVeryPulse/Minishell.git

2. Navigate into the cloned directory:

   cd Minishell

3. Compile the program using make:

   make

4. Run the minishell executable:

   ./minishell

Usage

Once the minishell program is running, you can interact with it using various commands and features:

Built-in Commands

• cd: Change directory

  cd /path/to/directory
  cd - # Goes back to previous directory
  

• echo: Print arguments to standard output.

  echo $PATH
  echo $?
  echo '$USER 123' "$USER 123"
  

• env: Without arguments: print environment variables; with arguments: run program in modified environment (see man env).

  env # prints all environment variables
  env PATH= ls # Set PATH to empty in a environment copy, then try running ls.
  

• exit: Exit minishell

  exit # return the value of the latest recorded exit status
  exit 123 # return specified value
  

• export: Add or modify environment variable values.

  export PATH=
  export a=1
  

• pwd: Print current directory.
• unset: Remove environment variable.

External Commands

Execute any external program by typing its name. Minishell searches for executable according to the PATH variable.

ls -l

Input/Output Redirection

Use <, >, <<, >> operators for input and output redirections.

cat < input.txt > output.txt
cat <<end >output1.txt | cat <<end >output2.txt

Piping

Pipe multiple commands together using the | operator. When there are pipes, all commands will be executed in child processes.

ls -l | grep .txt
cat file.txt | wc -l

Contributors

• theVeryPulse
• pejasco