Shell

bash basics

default text editor

• for inline shell call: sudo EDITOR=nano crontab -e

• add to ~/.bashrc or ~/.zshrc:

  • export EDITOR=nano

• for default root editor, edit also /root/.bashrc or /root/.zshrc

echo "export VISUAL=nano\nexport EDITOR=nano" >> ~/.bashrc
echo "export VISUAL=nano\nexport EDITOR=nano" >> ~/.zshrc

sudo sh -c "echo -e \"export VISUAL=nano\nexport EDITOR=nano\" >> ~/.bashrc"
sudo sh -c "echo -e \"export VISUAL=nano\nexport EDITOR=nano\" >> ~/.zshrc"

login message:

• for local user edit: nano ~/.profile
• for global: /etc/profile or /etc/bashrc (only for bash shell)

add for example:

#shell login message
echo -e "\n\n You are working on: \t\e[41m>>> subdomain.my-server.com <<<\e[49m\n\n"

custom shell prompt:

• for local user edit: nano ~/.profile
• for global: /etc/profile or /etc/bashrc (only for bash shell)

add for example:

#shell login message
alias PS1="\e[0;32m[\u@\h \w]\$ \e[0m"

• \u - user
• \h - host
• \w - current path

[test@ubuntu1 ~]$ <- in green

PS3 for select prompt

https://www.thegeekstuff.com/2008/09/bash-shell-take-control-of-ps1-ps2-ps3-ps4-and-prompt_command/

Terminal colors

• \e[0;32m

• \e[ – Begin color changes

• 0;32m – Specify the color code

• [\u@\h \W]\$ – This is the code for your normal BASH prompt (username@hostname Workingdirectory $)

• \e[0m – Exit color-change mode

The first number in the color code specifies the typeface:

• 0 – Normal
• 1 – Bold (bright)
• 2 – Dim
• 4 – Underlined

The second number indicates the color you want:

output redirection

• 2>&1 redirect StdErr to StdOut
• 2>&1 | redirect and Pipe, same as |& (not in sh)

          || visible in terminal ||   visible in file   || existing
  Syntax  ||  StdOut  |  StdErr  ||  StdOut  |  StdErr  ||   file   
==========++==========+==========++==========+==========++===========
    >     ||    no    |   yes    ||   yes    |    no    || overwrite
    >>    ||    no    |   yes    ||   yes    |    no    ||  append
          ||          |          ||          |          ||
   2>     ||   yes    |    no    ||    no    |   yes    || overwrite
   2>>    ||   yes    |    no    ||    no    |   yes    ||  append
          ||          |          ||          |          ||
   &>     ||    no    |    no    ||   yes    |   yes    || overwrite
   &>>    ||    no    |    no    ||   yes    |   yes    ||  append
          ||          |          ||          |          ||
 | tee    ||   yes    |   yes    ||   yes    |    no    || overwrite
 | tee -a ||   yes    |   yes    ||   yes    |    no    ||  append
          ||          |          ||          |          ||
|& tee    ||   yes    |   yes    ||   yes    |   yes    || overwrite
|& tee -a ||   yes    |   yes    ||   yes    |   yes    ||  append

zsh

all in one script

if test -f ~/.zshrc; then
  echo "Installing zsh with oh my zsh and powerlevel10kTheme"

  sudo apt update && sudo apt install curl git zsh
  sh -c "$(curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)" "" --unattended
  git clone --depth=1 https://github.com/romkatv/powerlevel10k.git ${ZSH_CUSTOM:-$HOME/.oh-my-zsh/custom}/themes/powerlevel10k
  sed -i '/ZSH_THEME="/c\ZSH_THEME="powerlevel10k/powerlevel10k"' ~/.zshrc
fi

To customize prompt, run p10k configure or edit ~/.p10k.zsh.

install zsh

• ZSH (shell with more features)
  • sudo apt install zsh or sudo dnf intall zsh (on Fedora)
• Oh-My-ZSH
  • sh -c "$(curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"

Oh My Zsh Cheatsheet

install powerlevel 10k theme

• install font for "powerlevel10k" https://github.com/romkatv/powerlevel10k#meslo-nerd-font-patched-for-powerlevel10k
• choose font Meslo Nerd in preferences of the terminal or editor
• install "powerlevel10k"-theme for ohmyzsh https://github.com/romkatv/powerlevel10k git clone --depth=1 https://github.com/romkatv/powerlevel10k.git ${ZSH_CUSTOM:-$HOME/.oh-my-zsh/custom}/themes/powerlevel10k
• Set ZSH_THEME="powerlevel10k/powerlevel10k" in ~/.zshrc.
  • sed -i '/ZSH_THEME="/c\ZSH_THEME="powerlevel10k/powerlevel10k"' ~/.zshrc
• Type p10k configure if the configuration wizard doesn't start automatically.

edit for visual studio code

• Press command + shift + P in your VSCode window.

• type settings.json and click "Open User Settings (JSON)" it.

• insert or add:

  {
    "terminal.integrated.fontFamily": "MesloLGS NF",
    "terminal.integrated.fontSize": 12,
    "terminal.integrated.defaultProfile.linux": "zsh"
  }
  

terminal emulator

terminator

• install: sudo apt install terminator

documentation

• Create more terminals by:
  • horizontal split: Ctrl-Shift-o
  • vertical split: Ctrl-Shift-e
• Shift focus to:
  • next terminal: Ctrl-Shift-n
  • previous terminal: Ctrl-Shift-p
• New tab: Ctrl-Shift-t
• New window: Ctrl-Shift-i
• Close terminal or tab:
  • Ctrl-Shift-w
  • or right mouse click -> Close
• Close window with all it's terminals and tabs: Ctrl-Shift-q
• Reset zoom: Ctrl-0