System Programming Basics

1. Introduction

From JavaScript Runtime to C System Programming

In JavaScript, you work within a runtime environment that abstracts away system-level operations. In C, you have direct access to the operating system, allowing you to create processes, handle signals, and make system calls.

💡 Key Concept: C system programming gives you low-level control over the operating system, enabling you to build system utilities, daemons, and high-performance applications.

2. Processes and Process Management

3. Threads and Concurrency

4. Signal Handling

5. System Calls and File Operations

6. Common Pitfalls

• Race conditions: Use proper synchronization mechanisms
• Signal handler safety: Only use async-signal-safe functions in signal handlers
• Resource leaks: Always close file descriptors and free allocated memory
• Process zombie: Properly wait for child processes
• Thread safety: Use mutexes and other synchronization primitives

7. Exercises

1. Write a program that creates multiple child processes and waits for all to complete.
2. Implement a simple shell that can execute commands.
3. Create a program that handles multiple signals gracefully.
4. Write a multi-threaded program that performs parallel computations.

8. Performance Analysis

• Process creation: More expensive than thread creation
• Inter-process communication: Slower than inter-thread communication
• System calls: Overhead compared to user-space operations
• Signal handling: Asynchronous and can interrupt normal execution
• Thread synchronization: Mutexes and semaphores provide safe concurrent access

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Summary: C system programming provides direct access to operating system features. Understanding process management, threading, signal handling, and system calls is essential for building system-level applications and utilities.