OS_Implement_Shell

Link to GitHub

Contents of Tar File:

• makefile
• parser.c
• README.md

How to compile executable:

Input these commands in your terminal in the directory where the extracted tar file contents are:

make

This should produce a "shell" executable that you can run by typing:

./shell

Project Statement

Design and implement a basic shell interface that supports input/output redirection, piping background processing, and a series of built in functions (echo, cd, exit, jobs).

Assumptions Made

• Error messages do not need to match the exact wording of bash
• Does not handle globs, regular expressions, special characters (except &, <, >, |, ~, and $), quotes, escaped characters, etc.
• No more than 10 background processes at the same time
• Multiple redirections of the same type will not appear in a single command
• Auto-complete not implemented
• Only expands environment variables given as whole arguments
• Piping and I/O redirection will not occur together in a single command
• No more than two pipes (|) will appear in a single command

Contributions by Group Member

Nicholas Tidwell

• implemented Environmental Variables
• implemented Prompt
• implemented Tilde Expansion
• implemented $PATH search
• implemented External Command Execution
• implemented i/o redirection
• implemented piping
• implemented 'cd'

William Tsaur

• created README.md
• created makefile
• modified environment variable parsing
• modified $PATH search implementation
• implemented External Command Execution
• modified i/o redirection
• modified piping
• implemented 'exit'
• modified 'cd'

Michael Styron

• implemented background processing
• implemented 'jobs'
• testing
• debugging

Extra Credit (task - implemented by)

• Shell-ception - Group
• Unlimited Piping - William Tsaur