Uses pdftoppm and img2sixel to print PDF pages in the terminal. requirements: xdotool, xwininfo, img2sixel, pdftoppm, python3. Usage: print_pdf [PDF] [SCALE]

print_pdf

#!/bin/bash

# 1. get number of pages
# 2. spawn a thread that reads up to N pages
# 3. run pdftoppm -png to mktemp
# 4. handle Ctrl+C

function print_png() {
  img2sixel "${1}" 2>/dev/null
}

function height_pixels() {
  echo "$(xwininfo -id $(xdotool getactivewindow) | grep Height | cut -d ':' -f 2 | xargs)"
}

function basic_cleanup() {
  rm -rf "${1}"
  cd "${2}"
  exit 0
}

function async_cleanup() {
  basic_cleanup "${1}" "${2}"
  kill -0 "${3}"
  wait "${3}"
}

function file_exists() {
  test -f "${1}"
}

function file_is_open() {
  test -n "$(lsof "$1")"
}

function file_is_ready() {
  if file_exists "$1" && ! file_is_open "$1";
  then
    return 0
  else
    return 255
  fi
}

function icat_until() {
  local BASE="${1}"
  local NUM_PAGES="${2}"
  local HEIGHT="$(( "$(tput lines)" - 1))"

  for i in $(seq -f "%0${#NUM_PAGES}g" 1 ${NUM_PAGES}); do
    local PNG="${BASE}-${i}.png"
    while ! file_is_ready "${PNG}";
    do
      sleep 0.5
    done
    print_png "${PNG}" "${HEIGHT}"
    read
  done
}

function num_pages() {
  pdfinfo "${1}" | grep "^Pages:" | awk '{ printf $2}'
}

TMP_DIR="$(mktemp -d)"
START="$(pwd)"
trap "basic_cleanup ${TMP_DIR} ${START}" SIGINT
cd "${TMP_DIR}"
HEIGHT_MULTIPLIER="0.9"

if [[ $# -ge 2 ]]; then
  HEIGHT_MULTIPLIER=$2
fi

if [[ $# -ge 1 ]]; then
    PDF="$START/$1"
    BASE=$(basename -s .pdf "${PDF}")
    NUM_PAGES=$(num_pages "${PDF}")
    echo "starting pdftoppm for ${NUM_PAGES} pages"
    pdftoppm -png "${PDF}" "${BASE}" -scale-to-y $(python3 -c "print(int($(height_pixels) * ${HEIGHT_MULTIPLIER}))" ) -scale-to-x -1 &
    CHILD_ID="$!"
    trap "async_cleanup ${TMP_DIR} ${START} ${CHILD_ID}" SIGINT
    icat_until "${BASE}" "${NUM_PAGES}"
    wait
fi

basic_cleanup "${TMP_DIR}" "${START}"