Examples for Customizing the Shell Prompt

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Description: Just some examples of what you can add to your shell prompt to make it your own.
I hope this helps anyone to create your own unique terminal prompt styles and themes.

Getting started

First we need to install myip from either the AUR or the clone the repository from Github MyIP.

Install from the AUR

yay -S myip

Or clone from Github

git clone https://github.com/make-github-pseudonymous-again/myip
cd myip
sudo make DESTDIR=/ PREFIX=/usr install

Now we make our personal bin direcotry and add it to our path.
This is where we will keep our custom scripts.

mkdir -p ~/.bin
cp /usr/bin/myip ~/.bin/myip
sudo chown $USER:$USER --reducersive ~/.bin
echo 'export PATH="$HOME/.bin:$PATH"' >> ~/.bashrc
source ~/.bashrc

Next we need to make the script myweather for our shell prompt.
Edit "YOUR_CITY_HERE" to your city.

echo -e "$(clear)\n"
curl -w -s 'v2.wttr.in/%20%20%20%20%20%20%20%20YOUR_CITY_HERE?u&format=%l\n%20%20%20%20Current%20Weather%20Forecast\n*%20Currently%20the%20temp. %20is:%20%c%t\n*%20But%20feels%20like:%20%f\n*%20With%20a%20U.V.%20index%20of:%20%u\n*%20Todays%20Sunrise%20is%20at:%20%S\n*%20Tonights%20Sunset%20is%20at:%20%s' 2>/dev/null
echo -e "\n"

Add it to the ~/.bin directory and make it executable.

mv myweather ~/.bin
chmod +x ~/.bin/myweather

Put these color environment variables to your .bashrc

##----------------------------------------------------------
## Color definitions (taken from Color Bash Prompt HowTo)
##----------------------------------------------------------

## Normal Colors
export Black='\e[0;30m'   # Black
export Red='\e[0;31m'     # Red
export Green='\e[0;32m'   # Green
export Yellow='\e[0;33m'  # Yellow
export Blue='\e[0;34m'    # Blue
export Purple='\e[0;35m'  # Purple
export Cyan='\e[0;36m'    # Cyan
export White='\e[0;37m'   # White

## Bold Colors
export BBlack='\e[1;30m'  # Bold Black
export BRed='\e[1;31m'    # Bold Red
export BGreen='\e[1;32m'  # Bold Green
export BYellow='\e[1;33m' # Bold Yellow
export BBlue='\e[1;34m'   # Bold Blue
export BPurple='\e[1;35m' # Bold Purple
export BCyan='\e[1;36m'   # Bold Cyan
export BWhite='\e[1;37m'  # Bold White

## Background Colors
export On_Black='\e[40m'  # On Black
export On_Red='\e[41m'    # On Red
export On_Green='\e[42m'  # On Green
export On_Yellow='\e[43m' # On Yellow
export On_Blue='\e[44m'   # On Blue
export On_Purple='\e[45m' # On Purple
export On_Cyan='\e[46m'   # On Cyan
export On_White='\e[47m'  # On White

## Reset Color Pallet
export NC='\e[m'          # Color Reset

## Blinking Text On/Off
export BLINK='\e[5m'      # Blinking Text

## Alarming Text Effects
export ALERT="${BRed}${BLINK}"             # Bold Red On Black Background
export DANGER="${BRed}${On_White}${BLINK}" # Blinking Bold Red On White Background

Advanced Colorization and Animated Text

Let's put all of that together into a function for your .bashrc file.

if [ "$TERM" = "xterm-256color" ]; then
  function myweather() {
    ~/.bin/myweather
  }

  if [ -x ~/.bin/myweather ]; then
    {
      echo -e "${Blue}$(~/.bin/myweather)${NC}"
      sleep 1
      echo -e "${Green}.................${NC}${BRed}${BLINK}WARNING${NC}${Green}.................${NC}
${BPurple} --- ${NC}${BBlue}力${NC}${BPurple}--- ${NC}${BRed}Anonymize your network${BPurple} ---${NC}${BBlue} 撚${NC}${BPurple}-- ${NC}
${Green}.........................................${NC}
${White} 數${NC}${BRed}Public IP Address: ${NC}${Black}${On_White}$(myip public)${NC}
${White} ﲬ${NC}${BRed} Private IP Address: ${NC}${Black}${On_White}$(myip private)${NC}
${Green}.........................................${NC}
${BPurple} --- ${NC}${BGreen}${NC}${BPurple} --- ${NC}${BGreen}Use a${NC}${BRed} VPN${NC}${BPurple} --- ${NC}${BGreen}or a${NC}${BPurple} --- ${NC}${BRed}Socks5 PROXY${NC}${BPurple} --- ${NC}${BYellow}${NC}${BPurple} --- ${NC}"
    } | {
      pv -qL $((18+(-3 + RANDOM%5)))
      pv -qL $((28+(-3 + RANDOM%5)))
    }
  fi
fi

This function is going to display the weather for your city and your public and private IP addresses as a warning.
So you know to change it if need be.

Example for On-Screen Early Alert System

Here's a working example to detect when fail2ban has detected a failed login attempt and then display a warning on the screen:

#!/bin/bash

# Check if fail2ban has detected a failed login attempt
if grep -q "Ban " /var/log/fail2ban.log; then
    # Send a desktop notification using zenity
    zenity --warning --text="A failed login attempt has been detected." --urgency=critical --timeout=3600
fi

In this modified script, we use zenity with the --warning option to display a warning dialog with a message indicating that a failed login attempt has been detected.

The --urgency=critical option sets the urgency level to high, and the --timeout=3600 option sets the timeout to 1 hour.

To run this script, you would save it to a file, for example ssh_warning_zenity.sh, give it execute permissions using chmod +x ssh_warning_zenity.sh, and then execute it in a terminal.

Please note that zenity is a command-line utility that is typically available on most Linux distributions.

If you're using a different operating system or if zenity is not installed, you would need to find an equivalent command or library for sending desktop notifications on that platform.

Using zenity provides a more interactive and user-friendly experience compared to a simple text-based warning on the screen. It allows the user to quickly acknowledge the notification and take appropriate action if needed.

Remember to adjust the timing and path to the script in the cron job or systemd service configuration file according to your specific requirements.

Here's an example of how you could set up a cron job to run the script every minute:

# Edit the crontab file
crontab -e

# Add the following line to run the script every minute
* * * * * /path/to/ssh_warning_notify_bell.sh

In this example, the ssh_warning_notify_bell.sh script is set to run every minute.

You would need to replace /path/to/ with the actual path to the script on your system.

Alternatively, you could set up a systemd service to run the script on boot or at a specific interval.

Here's an example of a systemd service configuration file:

[Unit]
Description=SSH Failed Login Attempt Notification

[Service]
ExecStart=/path/to/ssh_warning_notify_bell.sh
Restart=always

[Install]
WantedBy=multi-user.target

Save this file as ssh_warning.service in the /etc/systemd/system/ directory and then run the following commands to enable and start the service:

sudo systemctl enable ssh_warning.service
sudo systemctl start ssh_warning.service

By setting up a cron job or a systemd service, you ensure that the script runs automatically in the background without any user interaction.

The script will check for failed login attempts and send desktop notifications with an audible bell if necessary.

Visual Examples :)

One clip with the script running as is and the other split up with clear && added after sleep 1 in the function.

prompt.mp4

• In this next example the function clears the screen after the weather and before the network warning.
• Notice the artistic difference from the previous video where the text ends on the same column and the centered text. Small changes, (visualy) big differences.

prompt2.mp4

Happy Hacking