Understanding Shell Configuration in Linux

1. Shell Configuration
Dr.GINNE M JAMES
Assistant Professor
Department of Computer Science with Data Analytics
Sri Ramakrishna College of Arts and Science
Coimbatore - 641 006
Tamil Nadu, India
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2. What is Shell Configuration?
•Customizing the shell environment to enhance usability and productivity.
•Common Shells: Bash, Zsh, Fish, etc.

3. Shell Initialization Files
Bash Shell Initialization Files:
•.bashrc
•.bash_profile
•.profile
•/etc/profile
Zsh Shell Initialization Files:
•.zshrc
•.zprofile
•.zlogin
•/etc/zshrc

4. Environment Variables
•What are Environment Variables?
•Key-value pairs used by the shell to configure the environment.
•Common Environment Variables:
•PATH
•HOME
•USER
•SHELL

5. Setting Environment Variables
• Persistent Setting:
• Add to bashrc or zshrc
export PATH=$PATH:/new/path
• Temporary Setting
PATH=$PATH:/new/path

6. Aliases
• What are Aliases?
• Shortcuts for commands.
• Creating Aliases
alias ll='ls -la’
alias gs='git status'

7. Functions
• What are Functions?
Custom reusable commands.
• Creating Functions
function greet() {
echo "Hello, $1"
}

8. Shell Prompts
• Customizing the Shell Prompt:
PS1 variable in Bash:
PS1='u@h:w$ ‘
• Example for Zsh:
PROMPT='%n@%m:%~%# '

9. Using .bashrc and .bash_profile
•Purpose of .bashrc:
Executed for interactive non-login shells.
•Purpose of .bash_profile:
Executed for login shells.