Abstract


Quote

Linux Kernel is a file based but Windows is an API based.

This just means that in Linux, we can use the same file System Call (系统调用) on IO Device like Special File & Unix Domain Socket besides the regular files, where Windows has an separate Windowa API for those IO Devices.

  • Hide the nitty gritty of IO Device, so users can focus on manipulating the content inside the IO Device

  • Present programmer a clean Abstraction (抽象) of device-independent file

  • Examples are Printers & Modems etc


  • 2 parts - Filename & Inode Number, doesn’t have any metadata associated

File Descriptor

File Permission

  • In POSIX, file permissions are handled by rwx bits

Special File


Block Special Files

Character Special Files

  • Model IO Device that accept or output a character stream like keyboard

Line Break in File


  • POSIX systems uses a single character called Line Feed \n
  • While Windows uses carriage return and Line Feed, so 2 characters \r\n. This is because during typewriter times, you needed to mov the carriage to restart typing on the beginning of a line first, then turn the wheel to move the paper to change the line

Hands-On!

You can install dos2unix and unix2dos using Brew to play with line break.

You can view the hidden line break character by downloading and configuring bat.

Useful CLi Tools


bat

  • A cat clone with wings.
brew install bat && echo "alias cat='bat'" >>~/.zshrc

dua

  • Manage files fast, powered by rust!
brew install dua-cli
 
dua interactive

xcp

  • cp on tren!
cargo install xcp
# Alias to cp
alias cp="xcp"

xxd

  • Generate a hexdump from a binary file and display the output
xxd <BINARY_NAME.bin>