Output a Zelda-style heart meter for your MacBook's battery level. On the command line. Based on an idea from @stephencelis, executed by myself. For a tmux version, see https://gist.github.com/4324139

zelda-battery.sh

#!/usr/bin/env zsh
#
# Works best with blinking text; the last heart will blink
# when you have less than 25% of your battery life remaining.

BATTERY="$(pmset -g ps | awk 'NR==2' | perl -pe 's/.*?(\d+)%.*/\1/')"

if [[ $BATTERY -lt 25 ]]; then
  echo "\e[5;31m♥\e[0;31m♡♡\e[0m"
elif [[ $BATTERY -lt 50 ]]; then
  echo "\e[31m♥♡♡\e[0m"
elif [[ $BATTERY -lt 75 ]]; then
  echo "\e[31m♥♥♡\e[0m"
else
  echo "\e[31m♥♥♥\e[0m"
fi

Really, really great. But the hearts overlap in my terminal... I'm guessing this is due to the font I'm using?

http://cl.ly/image/062a3N231O2R

It looks great with Menlo, which is my preferred font... However, if you're using another, lesser font and your hearts are overlapping, you can check the "Unicode East Asian Ambiguous characters are wide" setting under Advanced in Terminal.app:

@spaceninja Yes, Monaco uses half-width hearts. Andale Mono and Courier New both do it right but they look awful.

Similar setting in Iterm2:

http://d.pr/i/zWis

The output of pmset -g ps becomes three lines when your battery approaches critical levels (under 20% remaining). So I've updated it to pipe to awk 'NR==2' instead of tail -1.

In case I have to look this up again, this is how I ended up doing it:

zelda() {
  BATTERY="$(pmset -g ps | tail -1 | perl -pe 's/.*?(\d+)%.*/\1/')"

  if [[ $BATTERY -lt 25 ]]; then
    echo "%{$fg_blink[red]%}♥%{$fg_bold[red]%} ♡ ♡ "
  elif [[ $BATTERY -lt 50 ]]; then
    echo "♥ ♡ ♡ "
  elif [[ $BATTERY -lt 75 ]]; then
    echo "♥ ♥ ♡ "
  else
    echo "♥ ♥ ♥ "
  fi
}

# Get the current ruby version in use with RVM:
if [ -e ~/.rvm/bin/rvm-prompt ]; then
    RUBY_PROMPT_="%{$fg_bold[blue]%}rvm:(%{$fg[green]%}\$(~/.rvm/bin/rvm-prompt s i v g)%{$fg_bold[blue]%})%{$reset_color%} "
else
  if which rbenv &> /dev/null; then
    RUBY_PROMPT_="%{$fg_bold[blue]%}rbenv:(%{$fg[green]%}\$(rbenv version | sed -e 's/ (set.*$//')%{$fg_bold[blue]%})%{$reset_color%} "
  fi
fi

# Get the host name (first 4 chars)
HOST_PROMPT_="%{$fg_bold[red]%}➜  %{$fg_bold[cyan]%}%c "
GIT_PROMPT="%{$fg_bold[blue]%}\$(git_prompt_info)%{$fg_bold[blue]%} % %{$reset_color%}"
PROMPT="%{$fg_bold[red]%}$(zelda)%{$reset_color%}$HOST_PROMPT_$RUBY_PROMPT_$GIT_PROMPT"