CS374-OS1

1. Overview
2. Assignments
   • HW1: Movie Data Processing
     • C Implementation
     • Rust Implementation
     • Features
       • Movie Year Search
       • Rating Analysis
       • Language Search
   • HW2: File Directory Processing
     • C Implementation
     • Rust Implementation
     • File Organization System
   • HW3: Small Shell
     • Built-in Commands
     • Process Management
     • Signal Handling
     • Variable Expansion
   • HW4: Multi-threaded Line Processor
     • Thread Pipeline
     • Buffer Management
     • Producer-Consumer Implementation
   • HW5: One-Time Pad System
     • Encryption Server/Client
     • Decryption Server/Client
     • Key Generation
     • Network Programming

This repository contains 5 programming assignments (HW1-HW5) implementing various system programming concepts in C and Rust.

• C Version:
  • Parses CSV files using custom string manipulation
  • Implements linked list data structure for movie records
  • Features menu-driven interface for searching/filtering movies
• Rust Version:
  • Uses csv crate for file parsing
  • Leverages HashMap for organizing movie data
  • Implements same functionality with Rust's memory safety features

• C Version:
  • Uses system calls (mkdir, chmod, stat)
  • Creates directory structure by year
  • Sets file permissions to rw-r----- (640)
  • Handles dynamic memory for file names and paths
• Rust Version:
  • Uses std::fs for file operations
  • Implements same functionality with Rust's file system APIs
  • Handles permissions using Rust's cross-platform abstractions

• Implements built-in commands (cd, status, exit)
• Handles foreground/background processes using fork() and exec()
• Implements signal handling (SIGINT, SIGTSTP)
• Supports I/O redirection using dup2()
• Variable expansion for $$ to PID
• Uses linked list to track background processes

1. Input Thread: Reads stdin until "STOP"
2. Line Separator Thread: Replaces \n with spaces
3. Plus Sign Thread: Converts ++ to ^
4. Output Thread: Formats 80-char lines

• Uses pthread mutex and condition variables
• Implements producer-consumer pattern
• Three shared buffers between threads
• Thread-safe memory management

• enc_server: Handles encryption requests
• enc_client: Sends plaintext for encryption
• dec_server: Handles decryption requests
• dec_client: Sends ciphertext for decryption
• keygen: Generates random keys

• Socket programming for client-server communication
• One-time pad encryption algorithm
• Error handling for bad characters/connections
• Key validation and length checking
• Concurrent server design

See individual homework directories for specific compilation and usage instructions.