42-minishell

The objective of this project is to create a simple shell, like an own little bash.
It is the first group project in the 42 core curriculum. I've done it with cadet tde-souza.

Project specifications

For the project we were allowed to use GNU's readline library which handles the terminal interaction (history & input reading). For everything else the subject allows only to use a few low-level functions.

Allowed functions: readline, rl_clear_history, rl_on_new_line,rl_replace_line, rl_redisplay, add_history, printf, malloc, free, write, access, open, read,close, fork, wait, waitpid, wait3, wait4, signal, sigaction, sigemptyset, sigaddset, kill, exit, getcwd, chdir, stat, lstat, fstat, unlink, execve, dup, dup2, pipe, opendir, readdir, closedir, strerror, perror, isatty, ttyname, ttyslot, ioctl, getenv, tcsetattr, tcgetattr, tgetent, tgetflag, tgetnum, tgetstr, tgoto, tputs

Features

Basics:

• History of previous entered commands
• Search and launch the right executable (based on the PATH variable, using a relative or an absolute path)
• Environment variables ($ followed by a sequence of characters) expand to their values
• ctrl-C, ctrl-D and ctrl-\ behave like in bash
• ’ (single quotes - prevent from interpreting meta-characters in quoted sequence)
• " (double quotes - prevent from interpreting meta-characters in quoted sequence except for $)
• $? expands to the last exit status
• | connect cmds or groups with pipes; output of a cmd is connected to the input of the next cmd via a pipe

Builtins:

• echo with option -n
• cd (relative or absolute path, - for OLDPWD, without arg for HOME)
• pwd without options
• export without options
• unset without options
• env without options
• exit [exit_status] without options

Redirections:

[n] (optional) specifies the file descriptor, if not specified it is stdout/stdin

• [n]< file Redirecting Input
• [n]<< limiter Here Documents
• [n]> file Redirecting Output
• [n]>> file Appending Redirected Output

How to use

The current version of minishell is developed and tested on macOS, but it should work on all UNIX/LINUX based systems as well.

Requirements:

• GCC / CLANG Compiler
• GNU Make
• GNU Readline library

git clone https://github.com/psydenst/minishell

cd minishell && make

./minishell

Dependencies

Install readline with brew

brew install readline

brew link --force readline

Add the path to the lib. IMPORTANT: The code won't compile if you don't add the correct path in Makefile.