ash Shell

This shell was written for Fall 2020 - Operating Systems course in C++.

Build Instructions

1. navigate to project folder ./ash
2. run make -f makefile or simply make to compile the code.
3. run ./ash

• note that the code utilises the GNU readline library for history and reading command input.

Features

• prompt message with current working directory
• pipelining multiple commands
• support for various built-in commands (see Built-in Commands)
• common aliases such as ls --color=auto and df -h
• a history of recent commands
• conversion of ~/ to $HOME/
• parameter passing
• inter-process communication using shared memory between shells
• batch mode and interactive mode
• ctrl+D termination and ctrl+C abortion

Built-in Commands

• help displays a help screen with a list of available commands
• cd [path] changes directory, supports ~/
• pwd prints workings directory in colour
• shid prints the shell id assigned by user
• send [shid] [message] sends a message to the other terminal
• receive reads all unread messages from the other terminal
• clear clears terminal output
• history prints a history of recent commands
• quit leaves the terminal (with a message)