Bash - Summary of this YouTube tutorial.

Test on Ubuntu Server 20.04.3 LTS (Focal Fossa)

1-Hello Bash Scripting

Example 1: Get all the shell availability on linux server.

$ cat /etc/shells

OUTPUT

# /etc/shells: valid login shells
/bin/sh
/bin/bash
/usr/bin/bash
/bin/rbash
/usr/bin/rbash
/bin/dash
/usr/bin/dash
/usr/bin/tmux
/usr/bin/screen

Example 2: Get current bash path

$ which bash

OUTPUT

/usr/bin/bash

Example 3: Create script

$ touch myfirstscript.py

Example 4: To see the script use "ls"

$ ls

OUTPUT

-rw-r--r-- 1 root root 0 Feb 8 10:02 myfirstscript.py

Example 5: Make it executable

$ chmod +x myfirstscript.py

OUTPUT

-rwxr-xr-x 1 roboscr roboscr 0 Feb 8 10:02 myfirstscript.py

Example 6: Write your first script, edit the script by using vi editor.

Filename: myfirstscript.py

Content on script:

#! /bin/bash 

echo "Hello Friends"

$ ./myfirstscript.py

OUTPUT

Hello Friends

2-Redirect to file

Example 1: Write to file in txt.

$ echo "Hello Friends" > newfile.txt

Example 2: Write to file in txt in append mode

$ echo "Hello Friends" >> newfile.txt

3-Comments

Example 1: Single line comments

# This is my first comment

# This is my second comment

Example 2: Multi line comments

: '

This is my first comment

This is my second comment

This is my third comment'

4-Conditional Statements

5-Loops

6-Script input

7-Script output

8-how to send output from one script to another scrpt

9-String Processing

10-Numbers and Arithmetic

11-Declare Command

12-Arrays

13-Functions

14-Files and Directories

15-Send Email Via Script

16-Curl in Scripts

17-Professional Menus

18-Wait for filesystem events with inotify

19-Introduction to grep

20-Introduction to awk

21-Introduction to sed

22- Debugging bash scripts