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"

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:

color	background	text
black	\e[0;40m	\e[0;30m
Red	\e[0;41m	\e[0;31m
Green	\e[0;42m	\e[0;32m
Brown	\e[0;43m	\e[0;33m
Blue	\e[0;44m	\e[0;34m
Purple	\e[0;45m	\e[0;35m
Cyan	\e[0;46m	\e[0;36m
Light gray	\e[0;47m	\e[0;37m

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

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

`~/.zshrc` file

# Enable Powerlevel10k instant prompt. Should stay close to the top of ~/.zshrc.
# Initialization code that may require console input (password prompts, [y/n]
# confirmations, etc.) must go above this block; everything else may go below.
if [[ -r "${XDG_CACHE_HOME:-$HOME/.cache}/p10k-instant-prompt-${(%):-%n}.zsh" ]]; then
  source "${XDG_CACHE_HOME:-$HOME/.cache}/p10k-instant-prompt-${(%):-%n}.zsh"
fi

# If you come from bash you might have to change your $PATH.
# export PATH=$HOME/bin:$HOME/.local/bin:/usr/local/bin:$PATH

# Path to your Oh My Zsh installation.
export ZSH="$HOME/.oh-my-zsh"

# Set name of the theme to load --- if set to "random", it will
# load a random theme each time Oh My Zsh is loaded, in which case,
# to know which specific one was loaded, run: echo $RANDOM_THEME
# See https://github.com/ohmyzsh/ohmyzsh/wiki/Themes
ZSH_THEME="powerlevel10k/powerlevel10k"

# Set list of themes to pick from when loading at random
# Setting this variable when ZSH_THEME=random will cause zsh to load
# a theme from this variable instead of looking in $ZSH/themes/
# If set to an empty array, this variable will have no effect.
# ZSH_THEME_RANDOM_CANDIDATES=( "robbyrussell" "agnoster" )

# Uncomment the following line to use case-sensitive completion.
# CASE_SENSITIVE="true"

# Uncomment the following line to use hyphen-insensitive completion.
# Case-sensitive completion must be off. _ and - will be interchangeable.
# HYPHEN_INSENSITIVE="true"

# Uncomment one of the following lines to change the auto-update behavior
# zstyle ':omz:update' mode disabled  # disable automatic updates
# zstyle ':omz:update' mode auto      # update automatically without asking
# zstyle ':omz:update' mode reminder  # just remind me to update when it's time

# Uncomment the following line to change how often to auto-update (in days).
# zstyle ':omz:update' frequency 13

# Uncomment the following line if pasting URLs and other text is messed up.
# DISABLE_MAGIC_FUNCTIONS="true"

# Uncomment the following line to disable colors in ls.
# DISABLE_LS_COLORS="true"

# Uncomment the following line to disable auto-setting terminal title.
# DISABLE_AUTO_TITLE="true"

# Uncomment the following line to enable command auto-correction.
# ENABLE_CORRECTION="true"

# Uncomment the following line to display red dots whilst waiting for completion.
# You can also set it to another string to have that shown instead of the default red dots.
# e.g. COMPLETION_WAITING_DOTS="%F{yellow}waiting...%f"
# Caution: this setting can cause issues with multiline prompts in zsh < 5.7.1 (see #5765)
# COMPLETION_WAITING_DOTS="true"

# Uncomment the following line if you want to disable marking untracked files
# under VCS as dirty. This makes repository status check for large repositories
# much, much faster.
# DISABLE_UNTRACKED_FILES_DIRTY="true"

# Uncomment the following line if you want to change the command execution time
# stamp shown in the history command output.
# You can set one of the optional three formats:
# "mm/dd/yyyy"|"dd.mm.yyyy"|"yyyy-mm-dd"
# or set a custom format using the strftime function format specifications,
# see 'man strftime' for details.
# HIST_STAMPS="mm/dd/yyyy"

# Would you like to use another custom folder than $ZSH/custom?
# ZSH_CUSTOM=/path/to/new-custom-folder

# Which plugins would you like to load?
# Standard plugins can be found in $ZSH/plugins/
# Custom plugins may be added to $ZSH_CUSTOM/plugins/
# Example format: plugins=(rails git textmate ruby lighthouse)
# Add wisely, as too many plugins slow down shell startup.
plugins=(git)

source $ZSH/oh-my-zsh.sh

# User configuration

# export MANPATH="/usr/local/man:$MANPATH"

# You may need to manually set your language environment
# export LANG=en_US.UTF-8

# Preferred editor for local and remote sessions
# if [[ -n $SSH_CONNECTION ]]; then
#   export EDITOR='vim'
# else
#   export EDITOR='nvim'
# fi

# Compilation flags
# export ARCHFLAGS="-arch $(uname -m)"

# Set personal aliases, overriding those provided by Oh My Zsh libs,
# plugins, and themes. Aliases can be placed here, though Oh My Zsh
# users are encouraged to define aliases within a top-level file in
# the $ZSH_CUSTOM folder, with .zsh extension. Examples:
# - $ZSH_CUSTOM/aliases.zsh
# - $ZSH_CUSTOM/macos.zsh
# For a full list of active aliases, run `alias`.
#
# Example aliases
# alias zshconfig="mate ~/.zshrc"
# alias ohmyzsh="mate ~/.oh-my-zsh"

# To customize prompt, run `p10k configure` or edit ~/.p10k.zsh.
[[ ! -f ~/.p10k.zsh ]] || source ~/.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](https://github.com/ohmyzsh/ohmyzsh/wiki/Cheatsheet)

##### install powerlevel 10k theme
* install font for "powerlevel10k"
  [https://github.com/romkatv/powerlevel10k#meslo-nerd-font-patched-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:

  ```json
  {
    "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`

Shell

bash basics

default text editor

login message:

custom shell prompt:

PS3 for select prompt

Terminal colors

output redirection

zsh

all in one script

~/.zshrc file

`PS3` for select prompt

`~/.zshrc` file