chruby-ctags

#!/usr/bin/env bash

set -e
shopt -s nullglob

index() {
  echo "  indexing $1"
  (builtin cd "$1"; ctags -R --languages=ruby)
}

index_LOAD_PATH() {
  local LOAD_PATH=()

  if [[ -d "$1"/lib/ruby && -w "$1"/lib/ruby ]]; then
    LOAD_PATH+=("$1"/lib/ruby/[0-9]*)
    LOAD_PATH+=("$1"/lib/ruby/shared*)
    LOAD_PATH+=("$1"/lib/ruby/site_ruby/[0-9]*)
    LOAD_PATH+=("$1"/lib/ruby/vendor_ruby/[0-9]*)
  elif [[ -d "$1"/lib && -w "$1"/lib ]]; then
    LOAD_PATH+=("$1"/lib "$1"/site "$1"/vendor)
  else
    echo "No \$LOAD_PATH directories found in $1" >&2
    return 1
  fi

  echo "Generating ctags for $1"

  for dir in ${LOAD_PATH[@]}; do
    [[ -d "$dir" ]] && index "$dir"
  done
}

RUBIES=()
[[ -d "$PREFIX/opt/rubies/" ]] && RUBIES+=("$PREFIX"/opt/rubies/*)
[[ -d "$HOME/.rubies" ]] && RUBIES+=("$HOME"/.rubies/*)

case "$#" in
  0)
    for dir in ${RUBIES[@]}; do
      index_LOAD_PATH "$dir"
    done
    ;;
  *)
    for dir in ${RUBIES[@]}; do
      [[ "${dir##*/}" == *"$1"* ]] && match="$dir"
    done

    if [[ -n "$match" ]]; then
      index_LOAD_PATH "$match"
    else
      echo "Unknown Ruby: $1" >&2
      exit 1
    fi
    ;;
esac