minishell

This project is about creating a Bourne-Again Shell (BASH) replica for the minishell project at Codam. Minishell is therefore a user-mode program that implements a Command Line Interface (CLI).

In general terms what this program does is:

• Print a prompt
• Read a line
• Parse
• Execute
• Repeat

Features

options

minishell:~$ pgrm -r -f path/to/file

i/o redirections

minishell:~$ pgrm < infile > outfile
minishell:~$ pgrm < infile >> outfile

pipes

minishell:~$ pgrm | pgrm2 | pgrm3

enviroment variables

minishell:~$ARG=something
minishell:~$ pgrm $ARG

previous foreground exit status

minishell:~$ pgrm $?

single quotes

minishell:~$ pgrm '$ARG $ARG2'

double quotes

minishell:~$ pgrm "$ARG $ARG2"

key bindings

• arrow up / down for history.
• ctrl-C displays a new prompt on a new line.
• ctrl-D exits the shell.
• ctrl-\ does nothing.

Built-ins

• echo with option -n
• cd with only a relative or absolute path
• pwd with no options
• export with no options
• unset with no options
• env with no options or arguments
• exit with no options

Missing

• scripting control
• command / filename completion
• background control
• initialization / startup files

system calls

• fork
• exec
• exit
• wait
• open
• close
• read
• write
• pipe
• dup
• chdir

GETTING STARTED

1. Clone the repo

git clone https://github.com/Chr-ss/minishell.git

2. cd into directory

cd minishell

3. Call the Makefile

make

SOURCES / ACKNOWLEDGEMENTS

Documentation in README https://github.com/DimitriDaSilva/42_minishell?tab=readme-ov-file#1-extracting-information

Shell

https://www.cipht.net/2017/10/17/build-your-own-shell.html https://github.com/tokenrove/build-your-own-shell

https://brennan.io/2015/01/16/write-a-shell-in-c/ https://github.com/brenns10/lsh Shell in C Bash Architecture Bash Manual

Parsing

Parsing without malloc (Andres)

https://craftinginterpreters.com/scanning-on-demand.html

Matching wildcards

https://www.geeksforgeeks.org/wildcard-pattern-matching/

Algorithms for parsing

https://en.wikipedia.org/wiki/Shunting_yard_algorithm https://eli.thegreenplace.net/2012/08/02/parsing-expressions-by-precedence-climbing https://www.cs.purdue.edu/homes/grr/SystemsProgrammingBook/Book/Chapter5-WritingYourOwnShell.pdf

Parsing Techniques A Practical Guide History of Parsing methods

Collaboration

Github Guide on Collaboration Jonathan Mines Github Collaboration Guide