.zshrc for fvm version in prompt

.zshrc

# place it somewhere in your .zshrc file e.g. just after setting the theme

# this is how I set powerlevel9k theme
# source /usr/local/opt/powerlevel9k/powerlevel9k.zsh-theme
# ZSH_THEME="powerlevel9k/powerlevel9k"

prompt_flutter() {
  local flutter_version
  flutter_version=$(command fvm flutter --version 2>/dev/null)
  # Remove "Flutter " (including the whitespace) from the beginning
  # of the version string and remove everything after the next
  # whitespace. This way we'll end up with only the version.
  flutter_version=${${flutter_version/Flutter /}%% *}

  # there's no dedicated icon for Flutter, so I just used ETC_ICON which is cog wheel
  if [[ -n "$flutter_version" ]]; then
    "$1_prompt_segment" "$0" "$2" "dodgerblue1" "$DEFAULT_COLOR" "$flutter_version" 'ETC_ICON'
  fi
}
POWERLEVEL9K_LEFT_PROMPT_ELEMENTS=(context dir vcs flutter)