This project is about creating a simple shell. Yes, our very own little bash.
Minishell is a project that aims to recreate a simplified version of the Bash shell, providing users with a functional command-line interface.
- Tokenizer: splits the user input into meaningful units (tokens) like commands, arguments, operators and redirection symbols
- Parser: builds a logical command structure from the token list — in our case, an Abstract Syntax Tree (AST)
- Execution: traverses the parsed structure, setting up input/output redirections, managing pipes between commands, and launching the appropriate built-in functions or external programs
- Signal handling: ensures the shell remains responsive and behaves correctly in interactive mode, handling user interruptions gracefully
- Display a prompt when waiting for a new command
- Have a working history
- Execute commands (using a relative or an absolute path)
- Built-ins implemented:
echowith-noptioncdwith a relative or absolute pathpwdwith no optionsexportwith no optionsunsetwith no optionsenvwith no options or argumentsexitwith no options
- Supports the pipe operator
|to connect commands - Redirections:
<redirects input>redirects output in truncate mode<<reads user's input in heredoc mode>>redirects output in append mode
- Environment variables:
$followed by a variable name, expands to the environment variable's value$?expands to the exit status of the most recently executed command'(single quotes) prevent the shell from interpreting the metacharacters"(double quotes) prevent the shell from interpreting the metacharacters, but allow variable expansion*(wildcards) expand files and directories that matches a certain pattern
- Logical operators:
&&executes the next command only if the previous one succeeded||executes the next command only if the previous one failed
- Signals in interactive mode:
ctrl-Cdisplays a new prompt on a new linectrl-Dexits the shellctrl-\does nothing