Bash is a Unix shell and command language written by Brian Fox for the GNU Project as a free software replacement for the Bourne shell.

The Advanced Bash Scripting Guide provides beginners with a simple introduction to the basics, and experts will find advanced details they need.

In this you will see the following things below.

Table of Contents

Part 1. Introduction
1. Shell Programming!
2. Starting Off With a Sha-Bang

Part 2. Basics
3. Special Characters
4. Introduction to Variables and Parameters
5. Quoting
6. Exit and Exit Status
7. Tests
8. Operations and Related Topics

Part 3. Beyond the Basics
9. Another Look at Variables
10. Manipulating Variables
11. Loops and Branches
12. Command Substitution
13. Arithmetic Expansion
14. Recess Time

Part 4. Commands
15. Internal Commands and Builtins
16. External Filters, Programs and Commands
17. System and Administrative Commands

Part 5. Advanced Topics
18. Regular Expressions
19. Here Documents
20. I/O Redirection
21. Subshells
22. Restricted Shells
23. Process Substitution
24. Functions
25. Aliases
26. List Constructs
27. Arrays
28. Indirect References
29. /dev and /proc
30. Network Programming
31. Of Zeros and Nulls
32. Debugging
33. Options
34. Gotchas
35. Scripting With Style
36. Miscellany
37. Bash, versions 2, 3, and 4
38. Endnotes

You will find all this section offline without any internet connection and lean DB easily anywhere and anytime.