Linux Guide (Part 10): Files, Everything is a File

What is a file?

01

In the Linux system, a file is an abstract representation of various resources (such as data, hardware devices, inter-process communication, etc.), following the principle of “everything is a file.” Whether it is ordinary data, directories, hardware devices, or inter-process communication interfaces, they all exist in the form of files and are operated through a unified interface.

The core idea of “everything is a file”

02

In the Linux system, almost all resources are abstracted as files, accessed and managed through a unified file interface. The core value of this concept lies in:

  • Unified interface: Regardless of hardware devices (such as hard drives, keyboards), software resources (such as processes, sockets), or ordinary data files, they can all be accessed through file operation functions (such as open, read, write), reducing the complexity of programming and system management.
  • Simplified logic: Abstracting complex system resources as files allows users and programs to operate without concerning themselves with the underlying implementation details, simply using file paths.

Typical application scenarios of “everything is a file”

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  1. Accessing hardware devices: Operate the hard drive through /dev/sda, and the sound card through /dev/audio, without worrying about hardware driver details.
  2. Process management:The /proc directory stores files related to processes (such as /proc/[pid]/exe pointing to the process executable), and process information can be obtained by reading these files.
  3. System configuration: Almost all system configurations exist in the form of text files (such as /etc/fstab storing disk mount information), making it easy to edit and modify directly.
  4. Shell script programming: Operate on pipes, sockets, and other resources through file interfaces, simplifying script logic (for example, cat /dev/null > log.txt clears the log file).

Linux Guide (Part 10): Files, Everything is a FileRecommended:

Recommended treasure website: A website for systematically learning programming

  1. Linux Guide (Part 1): Linux Kernel and Linux System
  2. Linux Guide (Part 2): Linux Command Line and Graphical User Interface
  3. Linux Guide (Part 7): Introduction to Directories, Characteristics and Functions of Directories, Common Directories
  4. Linux Guide (Part 9): User Directories, Home Directories
  5. Linux Guide (Part 8): FHS File System Hierarchy Standard
  6. Linux Commands (Part 4): Introduction to System Management Commands

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