Utility for updating flatpak apps on Ubuntu. GUI included.

update-flatpaks.sh

#!/bin/sh

# Add this script to your "Startup apps" to run it every time you sign into your OS.

updates_available=$(flatpak update | grep --perl-regexp '^\s*\d+\.\s+' | wc -l)

if [ "$updates_available" = 0 ]
then
  # This may be caused by a missing dependecy of a new version of an app to
  # update, so we need to explicitly check for that.
  </dev/null flatpak update >/dev/null 2>/dev/null
  if [ "$?" != 0 ]
  then
    update_message=$(</dev/null flatpak update 2>/dev/null)
    zenity \
      --question \
      --window-icon=question \
      --title="Flatpak updates available" \
      --width=480 \
      --text="$update_message"
    if [ "$?" != 0 ]
    then
      exit
    fi
    # Unfortunately, we cannot determine the number of updates in this case
    updates_available=1
  else
    echo "There are no updates available"
    exit
  fi
else
  if [ "$updates_available" = 1 ]
  then
    update_text="There is 1 flatpak update available. Install it now?"
  else
    update_text="There are $updates_available flatpak updates available. Install them now?"
  fi

  zenity \
    --question \
    --window-icon=question \
    --title="Flatpak updates available" \
    --width=480 \
    --text="$update_text"

  if [ "$?" != 0 ]
  then
    exit
  fi
fi

# Flatpak outputs a line on start of an update, so we need to count from -1 and
# add a "done" line at the end.
installed_updates=-1
( flatpak update --noninteractive && echo "All done" ) | (
while read -r line
do
  installed_updates=$(echo "$installed_updates + 1" | bc)
  echo "$installed_updates * 100 / $updates_available" | bc
done
) | zenity --progress --window-icon=info --text="Installing updates..." --no-cancel