Bash is a Unix shell written by Brian Fox for the GNU Project as a free software replacement for the Bourne shell. Released in 1989, it has been distributed widely as the default shell on Linux and Mac OS X. The document then explores various topics in Bash scripting including variables, conditional statements and loops, functions, string manipulations, I/O redirection, and special commands like grep, find, awk, sed, and alias.

1. Bash Script

3. • Bash is a Unix shell written by Brian Fox for the GNU Project as a
free software replacement for the Bourne shell .
• Released in 1989,it has been distributed widely as the shell for
the GNU operating system and as a default shell on Linux and
Mac OS X.

4. Let’s explore Bash Script…

5. 1.Variables

7. Global vs. Local variables

8. 2.Conditional statements and
loops

9. A.Conditional statements

10. If/else

11. Elif

12. Arithmetic Comparisons

13. Case

14. b.Loops

15. While

16. For(with numbers)

17. For(with directories)

18. For(with arrays)

19. Until

20. 3.Bash functions

21. Syntax to create a bash function:

22. Function with arguments

23. Functions with returned values

24. 4.String manipulations

25. a.String length

26. b.Substring extraction

27. c.Shortest Substring Match

28. d.Find and Replace String Values

29. e.Replace all the matches

30. f.Replace beginning and end

31. f.Replace beginning and end

32. 5.I/O Redirection

33. a.Standard Output “>”

34. a.Standard Output “>”

35. b.Standard Input “<“

36. b.Standard Input “<“

37. c.Pipes “|”

39. 6.Special commands

40. a.Grep
• Is used to search a characters chain within a file
• -v displays the lines that do not contain the string
• -c count the number of lines containing the string
• -n each line containing the string is numbered
• -x the line that exactly matches the string
• -l displays the names of files that contain the string

42. b.Find
• Is used to fined files based on specific criteria.
• Syntax: find <folder> <search criteria>
• -name search by name
• -perm search by access rihghts on file,
• -user search by file’s owner,
• -group search by file’s group,

46. c.Awk
• Is used to print specific lines and columns from a file, with
conditions.
• Syntax : awk '{print $NF}' file

49. d.Sed
• The SED UNIX Command in Linux enables you to work with the
text inside your files and can be used to perform different
functions to it.
• Syntax :

52. e.Alias
• Is used to enable a replacement of a command by another
string
• Syntax : alias myalias=“command_name”

53. Thank you for your attention