Lesson 4: The UNIX/Linux File System

• Demonstrate knowledge of the Unix directory hierarchy by locating and listing files within the directory structure
• Know how to navigate the directory hierarchy using the cd and ls commands
• Know the three elements of a file and why each is necessary
• Be able to use appropriate Unix commands to view the type and content of files

1. The UNIX Directory Hierarchy
   1. The root directory: (/)
      Contains a list of subdirectory names under which all files may be accessed.
   2. Absolute pathnames: Fully specified names starting from /
            /home/CIS90/guest
   3. Relative pathnames: A file name starting relative to the current working directory:
            Poems/Shakespeare/sonnet1
   
    
2. Navigating the file system
   1. The cd command
   2. The pwd command
   3. The ls command
   
    
3. File Types:
   1. Directory
   2. Ordinary
      • Programs
      • Text
      • Data
   3. Device
   4. Symbolic Links (short-cuts)
   
     The file command
    
4. Viewing Files
   1. Text files:
      • The cat command,
      • The more and less commands,
      • The head and tail commands
   2. Data files:
      • The xxd command