UNIX File System APIs: Writing Stat, List, Tail, and Search Tools

Interacting directly with the operating system is a fundamental skill for any developer, yet modern abstractions often hide how files and directories actually work. Understanding low-level file system APIs allows you to build highly efficient, reliable, and secure system utilities. This course bridges the gap between high-level code and the underlying operating system by teaching you how UNIX-style programs operate under the hood. You will transition from writing basic application code to developing system-level programs that query metadata, traverse directories, and monitor files. By studying core UNIX concepts and modern system programming practices, you will gain a deep mental model of file descriptors, storage allocation, and system calls. What you'll learn: - Understand foundational UNIX file system architecture, including inodes, file descriptors, and system call interfaces - Query file metadata and permissions programmatically using the stat API - Implement directory listing utilities to read and format directory contents - Build a custom tail utility to read and monitor the end of growing files - Design recursive search algorithms to traverse deep directory structures efficiently - Apply robust error handling, modern type safety, and resource management to prevent memory leaks - Practice writing clean, secure system-level code that respects file permissions and access controls Starting with basic definitions of files and directories, the course guides you through core system calls, metadata retrieval, and stream manipulation, culminating in the creation of practical system utilities. You will learn entirely through clear, written explanations and structured code walkthroughs. This course is designed for beginner to intermediate programmers who want to understand system-level programming and file system mechanics. No prior experience with systems programming is required, though basic familiarity with terminal commands and a core programming language is helpful. Start reading today to master the core APIs that power UNIX system utilities.