Shell Workout

Basic Exercises

1. Print a String with Quotation Marks

   • Write a command to print the string Use " man echo" including the quotation marks
   • Hint: Use double quotes in the inner string and wrap the whole thing in single quotes

2. Sleep Command

   • Read man sleep and figure out how to make the terminal “sleep” for 5 seconds before running another command
   • Example: Sleep before printing “Hello, World!”

3. Canceling a Long-Running Command

   • Execute the command sleep 5000
   • Realize that’s well over an hour
   • Learn how to cancel the running command

4. File Manipulation Sequence

   • Create an empty file called foo
   • Rename foo to bar
   • Copy bar to baz

5. List Specific Files

   • List only the files starting with “b” in the current directory
   • Hint: Use a wildcard

6. Efficient File Removal

   • Remove both bar and baz using a single rm command
   • Hint: Check if those are the only two files in the directory starting with “b”

7. Create a Text File

   • Create a file hello.txt containing the text “Hello, World!”
   • Use echo and a redirect >

8. Simple Greeting Shell Script

   • Write a shell script that greets the user
   • Hint: The current user is stored in the $USER environment variable in most shells

Intermediate Exercises

9. File Content Extraction

   • Use head and tail to display:
     • First 5 lines of a text file
     • Last 3 lines of a text file
   • Bonus: Combine these in a single command pipeline

10. Find Large Files

    • Create a command that finds all files in the current directory larger than 1MB
    • Hint: Use find with size parameters

11. Directory Analysis Script

    • Write a shell script that:
      • Takes a directory path as an argument
      • Counts the number of files in that directory
      • Prints the total size of all files in that directory
      • Displays the 3 largest files in that directory

12. Log File Analysis with grep

    • Use grep to:
      • Find all lines containing the word “error” in a log file
      • Count the number of error lines
      • Make the search case-insensitive

13. File Existence and Permissions Script

    • Create a shell script that:
      • Checks if a file exists
      • If it exists, display its permissions
      • If it doesn’t exist, create an empty file with read and write permissions for the owner

14. Text Transformation with tr

    • Use tr to:
      • Convert a text file to uppercase
      • Remove all digits from a text file
      • Squeeze multiple spaces into a single space

15. File Size Ranking Pipeline

    • Write a command that uses pipes to:
      • List all files in a directory
      • Sort them by size
      • Display the top 5 largest files

Advanced Exercises

16. Backup Utility Script

    • Create a shell script that acts as a simple backup utility:
      • Takes a source directory and destination directory as arguments
      • Uses tar to create a compressed backup
      • Names the backup with the current date (use date +%Y-%m-%d)
      • Optionally, keep only the last 5 backups by removing older ones

17. System Resource Monitor

    • Write a script that monitors system resources:
      • Use top or ps to capture CPU and memory usage
      • Write the output to a log file
      • If memory usage exceeds 80%, send an alert message

18. Python Function Analyzer

    • Create a command pipeline that:
      • Finds all Python files in a directory
      • Extracts all function definitions
      • Counts the number of functions
      • Sorts functions by name

19. Selective File Archiver

    • Write a shell script that:
      • Takes a file extension as an argument
      • Finds all files with that extension in the current directory and subdirectories
      • Calculates and displays the total size of those files
      • Creates a compressed archive of those files

20. Environment Variable Manager

    • Design a script that:
      • Checks the current environment variables
      • Allows adding a new environment variable
      • Allows removing an existing environment variable
      • Displays all current environment variables

Bonus Challenges

21. tmux Monitoring Session

    • Create a tmux session script that:
      • Opens multiple panes
      • Runs different monitoring commands in each pane
      • Automatically attaches to the session

22. Comprehensive System Information Script

    • Write a script that displays:
      • Current user
      • Disk usage
      • CPU and memory usage
      • Top 5 running processes
      • Network interface information

23. Log Rotation Script

    • Develop a log rotation script that:
      • Takes a log file path as an argument
      • Compresses old log files
      • Keeps only the last N log files
      • Can be scheduled with cron

24. Remote File Synchronization

    • Create a script using scp that:
      • Takes source and destination paths
      • Synchronizes files
      • Handles different remote server configurations
      • Provides verbose output

25. Interactive System Maintenance Menu

    • Design an interactive menu-driven shell script that:
      • Provides options for system maintenance tasks
      • Includes options like disk cleanup, process management, backup
      • Uses select for menu creation
      • Implements error handling and input validation