The Linux Terminal / Command Line

Here’s a concise guide covering the basics of The Linux Terminal / Command Line and the topics you listed:

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1. 🖥️ The Linux Terminal / Command Line

🔓 Opening the Terminal

• GUI Desktop (e.g., GNOME, XFCE):

  • Press Ctrl + Alt + T or search “Terminal” in your applications menu.

• TTY Console (CLI only systems):

  • Use Ctrl + Alt + F1 to F6 to switch to a terminal session.

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2. ⚙️ Terminal Settings

Terminal settings depend on the emulator you’re using (e.g., GNOME Terminal, Kitty, Alacritty):

• Font / Color scheme: Usually in Preferences → Appearance.
• Scrollback / History Size: Preferences → Scrolling.
• Shell configuration file: Typically ~/.bashrc or ~/.zshrc.

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3. 🔁 Common Terminal Commands

Command	Description
bash	Starts a new Bash shell session.
echo	Prints text or variables: echo $HOME.
env	Shows current environment variables.
export VAR=value	Sets environment variables: export PATH=$PATH:/new/path.
pwd	Prints current working directory.
set	Shows or sets shell options and variables.
unset	Removes shell variables: unset VAR.
man command	Shows manual for a command: man ls.
uname -a	Displays system information.
history	Lists previously run commands.
cat ~/.bash_history	Shows command history from file.

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4. 🎨 Customizing the Shell Prompt & Environment

• PS1 is the variable that defines your prompt:

  export PS1="\u@\h:\w\$ "
  

  • \u – Username
  • \h – Hostname
  • \w – Working directory
  • $ – Dollar sign (or # for root)

• Example: Colorful Prompt

  export PS1="\[\e[1;32m\]\u@\h\[\e[0m\]:\[\e[1;34m\]\w\[\e[0m\]\$ "
  

• To make permanent, add to ~/.bashrc.

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5. ⚡ Creating Aliases

• Temporarily create an alias:

  alias ll='ls -alF'
  

• Permanently add to ~/.bashrc or ~/.bash_aliases:

  echo "alias update='sudo pacman -Syu'" >> ~/.bashrc
  source ~/.bashrc
  

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