nsh

A Minimalist Linux Terminal Shell.

Instructions to start the terminal

Clone the repo and change directory: git clone https://github.com/NJnisarg/nsh && cd nsh/
Run the make script: make
While running the make command, it will ask for password, since it installs the nsh in /bin/nsh. If you don't want that please, remove it from the Makefile.
To run the terminal: nsh
The Makefile has 4 different targets: all, build, install and clean. build and install are ran internally by all.
To clean up everything, run make clean. This command will also ask for sudo password since it attempts to remove the /bin/nsh entry.

The Terminal shell, has 2 major components: 1.) The Parser and 2.) The Executor
The Parser component is built using Lex and Yacc and GNU Readline library, where as the executor is organized in the command.h and command.c files
The Lex is used for getting a Tokenizer/scanner(lexical analyzer) and Yacc is used to get the Parser that parses the Grammar for the shell commands.
The executor code and the data structures to hold the commands (Command table) are defined in the command.h and command.c files.

The shell tries to mimic the bash shell grammar.
It has simple commands implemented
It has I/O Redirections implemented
It has Pipes and Pipelines implemented
It supports cd
Supports tab-completion for filenames and history and up-arrow-key command history

It does not support compound commands, lists/pipeline lists and shell scripting
It does not support shell environment and variables.