uniprompt.sh
projects → uniprompt.sh

icon

In the early 90ies I used ansi.sys under DOS to get a colored prompt. With that it got much easier to spot where the last command was executed. Ten years later I switched to Linux and hardly missed that. The configuration of PS1 was one of the first more advanced configurations I ever did and I reworked my prompt every now and then and made it better every time. This version is a slightly modified version of it, which I was using for the last five years. It has proven to work under different operating systems, is easy to understand and much faster than powerline. I know, that it looks a lot like powerline, but it was not really inspired by that. There are simply not many characters compatible with the linux console and virtual terminals.

Usage

source uniprompt.sh

Installation

Put the above command into your ~/.bashrc and install and configure your terminal emulator to use a nerdfont.

The Script

Well. I will have to rethink how I deploy it, because a repository would definitly be better, but there it is and as I said: It changes so rarely nowadays. Have fun.

#!/usr/bin/bash

# sanity checks first: decide, when NOT to run...
[ -z "$PS1" ] && return

# to begin with: a random background color for each shell makes them easier to
# distinguish. Most virtual terminal emulators support TRUECOLOR today.
COLOR_BG_R=$((RANDOM % 255))
COLOR_BG_G=$((RANDOM % 255))
COLOR_BG_B=$((RANDOM % 255))

COLOR_BACKGROUND="\e[38;2;$COLOR_BG_R;$COLOR_BG_G;$COLOR_BG_B"m
COLOR_FOREGROUND="\e[48;0m"

# Here comes the approximation of the perceived brightness of colors: To allow
# the foreground to stand out it has to be considered. 0.2126R + 0.7152G +
# 0.0722B would be correct for relative luminance, but this approximation is
# close enough to determine either white or black as text color.
if [ $(expr $COLOR_BG_R / 3 + $COLOR_BG_G / 1 + $COLOR_BG_B / 8) -gt 240 ]; then
  COLOR_FOREGROUND="\e[48;2;0;0;0m"
else
  COLOR_FOREGROUND="\e[48;2;255;255;255m"
fi

# set window title according to exit status
function setWindowTitle() {
  local exit_status="$1"
  if [[ $? != $exit_status ]]; then # in case of an error
    echo -ne "]0; ${PWD}"  # window title
    printf "%*s%s" $(($(tput cols)-6)) "" "  $exit_status"
  else
    echo -ne "]0; ${PWD}"  # window title
  fi
}

function getClockSymbol() {
  # intential space  v123456789... you get the point :)
  local CLK_SYMBOLS=" "
  local HOUR=$(date +%I | sed -e 's/^0//')
  test $HOUR -ge 12 && HOUR=$(expr $HOUR - 12) # middach
  test $(date +%M) -gt 30 && HOUR=$(expr $HOUR + 1) # floor
  echo -ne ${CLK_SYMBOLS:HOUR:1}
}

function getUserSymbol() {
  case "$USER" in
    root)  echo "⚙️ " ;;
    *)     echo " " ;;
  esac
}

function getGitBranch() {
  GIT_BRANCH=""
  GIT_SUMMARY=""
  if git rev-parse --git-dir 1>/dev/null 2>/dev/null; then
    GIT_BRANCH=$(git branch 2>/dev/null | grep '^*' | colrm 1 2)
    GIT_SUMMARY=$(git log --oneline -1 --pretty=format:%s)
    GIT_BRANCH_DESCRIPTION=$(git config branch.$GIT_BRANCH.description 2>/dev/null)
  fi
  echo -ne "${GIT_BRANCH:+  │    $GIT_BRANCH}"
  echo -ne "${GIT_BRANCH_DESCRIPTION:+ - $GIT_BRANCH_DESCRIPTION}"
  # echo -ne "${GIT_SUMMARY:+ - $GIT_SUMMARY}"
}

function prompt() {
  setWindowTitle $?
  echo -e "\n" $( # make this write as atomic as possible to avoid flickering
  tput cuf $(($(tput cols)-15))
  echo -ne $COLOR_BACKGROUND
  echo -ne "" # reset background
  echo -ne "" # inverse revert
  echo -ne ""
  echo -ne ""
  echo -ne $COLOR_FOREGROUND
  echo -ne " "
  getClockSymbol
  echo -ne " "
  date +%H:%M:%S
  echo -ne " "
  echo -ne "░"
  echo -ne "
"
  echo -ne "░"
  echo -ne " "
  getUserSymbol
  echo -ne $USER@$HOSTNAME
  echo -ne " "
  echo -ne " "
  getGitBranch
  echo -ne " "
  echo -ne "" # reset background
  echo -ne "" # inverse revert
  echo -ne ""
  echo -ne ""
  echo ""
  echo ""
  ) "\n"
}

export PS1=" \[\033[38;2;210;160;50m\]  \[\033[0m\]\w  "
trap 'echo -ne "]0; ${BASH_COMMAND}"' DEBUG
export PROMPT_COMMAND=prompt

# vim: shiftwidth=2 tabstop=2 softtabstop=2 expandtab
top