Make alacritty into a pop-up scratchpad

text_scratchpad.sh

#!/usr/bin/env bash

set -Eeuf -o pipefail

log() {
  echo "$*" > /dev/stderr
}

err() {
  log "$*"
  exit 1
}

main() {
  local extra_paths

  # inverted order
  extra_paths=(
    /Applications/Alacritty.app/Contents/MacOS
    /run/current-system/sw/bin
    /etc/profiles/per-user/"${USER}"/bin
  )

  for p in "${extra_paths[@]}"; do
    PATH=${p}:${PATH}
  done

  local platform
  platform=$(uname -s)

  local clip paste
  case "${platform}" in
    Darwin)
      clip=(pbcopy)
      paste=(pbpaste)
      ;;
    Linux)
      clip=(xclip -r -selection clipboard)
      paste=(xclip -selection clipboard -out)
      ;;
    *)
      err "Unknown platform: ${platform}"
      ;;
  esac

  local -r tmp_file=$(mktemp)
  trap 'rm -f '"${tmp_file}" EXIT

  "${paste[@]}" > "${tmp_file}"
  alacritty \
    --class="__text_scratchpad" \
    --command hx "${tmp_file}" &&
    # this removes the trailing newline
    printf "%s" "$(< "${tmp_file}")" | "${clip[@]}"

  # belt and suspenders for cleanup
  rm -f "${tmp_file}"
}
main "$@"