CS 552 - Homework 3: Execution Integrity and Do Process

Author: Jim Buffenbarger, Miguel Carrasco Belmar Date: October 21, 2025
Course: CS 552
Assignment: HW3

Overview

This is an implementation of a simple Unix shell. This assignment's purpuse is to learn and practice multipprocess programming. The shell will support sequences, pipelines, I/O redirection, compound commands, subshells, and job control (e.g, fg and bg).

Grammar of this Shell

sequence ::= pipeline pipeline & pipeline ; pipeline & sequence pipeline ; sequence pipeline ::= command command | pipeline command ::= words redir ( sequence ) redir { sequence } redir words ::= word words word redir ::= ^ < word > word < word > word

Files Included

• Command.h - Command Execution interface
• Command.c - Command interface implementation
• Interpreter.h - Interpreting parse trees interface
• Interpreter.c - Interpreting parse trees implementation
• Jobs.h - Job control interface
• Jobs.c - Job control implementation
• Parser.h - Parsing input into a parse tree interface
• Parser.c - Parsing input into a parse tree implementation
• Pipeline.h - Pipeline data structure and operations interface
• Pipeline.c - Pipeline data structure and operations implementation
• Scanner.h- Scanner module interface
• Scanner.c - Scanner module implementation
• deq.c - Main implementation of the deque data structure from hw1
• deq.h - Header file with program interface hw1
• error.h - Error handling hw1
• valgrind_results.txt - Output of test function showing valgrind output
• Sequence.h - Sequence Module interface
• Sequence.c - Sequence Module implementation
• Shell.c - Main function
• Tree.h - Tree data structure interface
• Tree.c - Tree data structure implementation
• Test Directory - Test files for testsuite
• test_output.txt - Test results
• manual_job_control_test.txt - proof of working job module with fg and bg

How to Run

make ./shell

To test

test/run

Resources

-Starter code provided by Professor Jim Buffenbarger. -GitHub Copilot -Chat GPT5