Unix by Nick Gomez, Chris Rees, Brian Hernandez, Hector Rodriguez

Features

• Hierarchical File System
• Compatible File, Device, and Inter-Process I/O
• Asynchronous Processes
• System Command Language
• Supports Multiple Users

The File System

Let’s see why the UNIX file system was so unique for its day!

Three Types of Files

1. Ordinary Files

• Binary (executable) files
• Plain text files
• Symbolic links

Three Types of Files

• Directories
• Provides mapping between file names and files
• Allows paths (e.g. /home/uname/Desktop)
• The base directory called root (e.g. / )
• . and .. indicate current and parent directory respectively: /usr/local/.. same as /usr

Three Types of Files

Important Note

Files do not exist inside directories. Rather, directories store file names and pointers to the information that describes the file.

Three Types of Files

• Special Files
• Represents a particular device
• Read from and write to like normal files
• Unlike normal files, it interacts with associated devices
• Stored in the /dev directory