Repository Guidelines

Project Structure & Module Organization

src/ holds the shell implementation, with submodules for builtins/, executor/, parser/, and variables/.
src/builtins/ currently includes: cd, echo, env, exit, export, pwd, unset.
include/ contains public headers used across modules.
lib/ is populated at build time with third-party 42 libraries (libft, get_next_line, ft_printf, ft_args).
docs/ stores project references and manual test notes (see docs/tests.md).
build/ is the object output directory generated by make.

make or make all: build minishell (auto-clones required libs into lib/).
make clean: remove objects in build/.
make fclean: remove objects and the minishell binary (also cleans libs).
make re: full rebuild.
./minishell: run locally after a build.
make DEBUG=lldb or make DEBUG=valgrind or make DEBUG=address: rebuild with debug/ASan-friendly flags.

The codebase follows 42 Norminette v4 rules. Run norminette *.c *.h (or on specific files) before submitting changes.
Keep file names lowercase with underscores (e.g., src/builtins/echo/echo.c).
Keep headers in include/ and expose only what modules need.
Before adding or changing code, check allowed.txt to know which functions are permitted.
Any function not listed in allowed.txt is not allowed in this project.

There is no automated test runner. Use manual checks in docs/tests.md and basic shell behavior checks (pipes, redirects, builtins).
A local builtin edge-case script exists at tests/builtins_edge_cases.sh (expects a compiled ./minishell).
When debugging memory issues, run under valgrind and use the suppression file in valgrind/readline.supp.

cd: handles HOME fallback, cd - via OLDPWD, updates PWD/OLDPWD, and returns failure on invalid usage (too many arguments, missing HOME/OLDPWD).
echo: supports repeated -n flags (-n, -nnn) and prints remaining args preserving spaces between tokens.
env: prints current environment as KEY=VALUE; returns failure when called with extra arguments.
exit: validates numeric argument (with overflow checks), returns 1 on too many arguments without exiting, and exits with 2 on non-numeric argument.
export: supports NAME=VALUE and NAME (stored as empty value), validates identifiers, and returns failure when any identifier is invalid.
pwd: prints working directory using dynamic getcwd and returns failure if getcwd fails.
unset: validates identifiers and removes matching variables from the environment map.

Commit messages in this repo use a simple type: summary format (examples: update: ..., fix: ...). Keep summaries short and specific.
For PRs, include:
1. What changed and why.
2. How to test (commands or manual steps).
3. Notes on any parser/executor/builtin behavior changes.

The project depends on readline; ensure your system has libreadline-dev or equivalent before building.