1. /dev/null
2. Local variable
3. Global variable
4. Conditional Execution
5. File Descriptor
6. Functions
7. Dialog utility
8. Trap Command
9. Shift Command
10. Getopts
11. Cut Utility
12. Paste Utility
13. Join Utility
14. Awk Utility
15. Sed Utility
16. Uniq Utility
17. Grep Utility
18. Ex Utility
19. Doing arithmetic with awk
20. Predefined variable of awk
21. User-defined variable of awk
22. Printf Statement
23. Getline