MIDI keyboard and Linux

To get your MIDI keyboard working in Linux, you should do something like the following steps:

1) install Rosegarden, which automatically install jack and the related software in particular Qjackqtl (jack GUI). Maybe you could install directly Qjackqtl…

2) add your user to the audio group

sudo usermod -a -G audio <your_user_name>

3) install Qsynth,
4) do the following terminal command

sudo apt update; sudo apt full-upgrade -y; sudo apt install -y pipewire-audio-client-libraries libspa-0.2-bluetooth libspa-0.2-jack wireplumber pipewire-media-session-; sudo cp /usr/share/doc/pipewire/examples/alsa.conf.d/99-pipewire-default.conf /etc/alsa/conf.d/; sudo cp /usr/share/doc/pipewire/examples/ld.so.conf.d/pipewire-jack-*.conf /etc/ld.so.conf.d/; sudo ldconfig; sudo apt remove -y pulseaudio-module-bluetooth; systemctl --user --now enable wireplumber.service

Musescore and a MIDI keyboard

To get Musescore able to record from a MIDI keyboard I had to use the 4 release, so far with an appimage from their website.

Pop-up footnotes (at the window bottom)

A good starting point is the Hugo footnotes

But I have done some improvements (according to my needs), as the following:

  1. link (at the end of a html page) the file footnotes.js, with this content:
function getFootnoteContent(index) {
  const id = "fn:" + index;
  const fn = document.getElementById(id);
  return fn.innerHTML.trim();

function footnotePopup(showIndex, showCloseBtn) {
  const popupWrapper = document.querySelector("#popup-wrapper");

  // Set whether to display index and/or close button. Default is true for both
  if (showIndex === undefined) {
    showIndex = true;

  if (showCloseBtn === undefined) {
    showCloseBtn = false;

  // Create main container that will hold footnote content
  const popupContent = popupWrapper.appendChild(document.createElement("div"));
  popupContent.id = "popup-content";

  let popupIndex = null;
  if (showIndex) {
    popupIndex = popupWrapper.insertBefore(
    popupIndex.id = "popup-index";

  let popupCloseButton = null;
  if (showCloseBtn) {
    popupCloseButton = popupWrapper.appendChild(document.createElement("div"));
    popupCloseButton.innerHTML = "[x]";
    popupCloseButton.id = "popup-close";

  // Remove redundant [return] links from footnote list (optional)
  const fnReturns = document.querySelectorAll("a.footnote-return");
  fnReturns.forEach(function (fnReturn) {
    const parent = fnReturn.parentNode;

  const fnRefs = document.querySelectorAll("a[id^='fnref:']");
  fnRefs.forEach(function (fnRef) {
    fnRef.addEventListener("click", handler("refs", fnRef));

  //window.addEventListener("scroll", handler("close"));
    function (event) {
      if (
        event.target.matches("a[id^='fnref']") ||
      ) {
      popupWrapper.style.display = "none";

  if (showCloseBtn) {
    popupCloseButton.addEventListener("click", handler("close"));

  function handler(type, node) {
    return function (event) {
      if (type === "close") {
        popupWrapper.style.display = "none";

      if (type === "refs") {

        const index = node.id.substring(6);

        if (showIndex) {
          popupIndex.innerHTML = index + ".";

        popupContent.innerHTML = getFootnoteContent(index);
        popupWrapper.style.display = "flex";

footnotePopup(false, true);

2) Put, before that link, the div where the note will be shown

<div class=\"bottom-panel\" id=\"bottom-panel\">
 <div class=\"popup-wrapper\" id=\"popup-wrapper\"></div>

3) Modify the anchor tag (within your main text), with something like

<a href="#n1" id="fnref:1">[1]</a> 

4) and the footnote should be like the following:

<p id="fn:1"><a href="#fnref:1">[1]</a> your footnote here.</p> 

Update a mysql table replacing it

Replacing a table with the same name, I mean. You have to add, before “CREATE TABLE tablename” this row:

DROP TABLE tablename;

You can also add single rows, exporting them, and importing in a sql query, like the following:

INSERT INTO bibliografie (ID, autore, autore_nome, titolo, imagelink, sigla, tipologia, curatori, curatore_unico, opera, rivista, num, pagg, edizione, luogo, data, data_spec, trad_titolo, trad_edizione, trad_luogo, trad_data, contenuti, keywords, reperibilita, letto, letto_quando, valutazione, riferito, destinazione, ambito, href, ad_code) VALUES
(1880, 'Godechot', 'Jacques', 'La Révolution française : chronologie commentée, suivie de notices biographiques sur les personnages cités', NULL, 'Godechot [1988]', 'libro', NULL, NULL, NULL, NULL, NULL, NULL, 'Perrin', 'Paris', '1988', NULL, 'La Rivoluzione francese. Cronologia commentata 1787-1799', 'Bompiani', 'Milano', '2001', '', 'Rivoluzione francese ', NULL, NULL, NULL, NULL, NULL, NULL, 'storia', NULL, NULL);

Vivaldi public key issue

After several unsuccessfull attempts to fix a Vivaldi NO_PUBKEY error, I found this working solution:

wget -qO- https://repo.vivaldi.com/archive/linux_signing_key.pub | gpg --dearmor | sudo dd of=/usr/share/keyrings/vivaldi-browser.gpg

and then:

sudo apt update

grub rescue

It could happen that your PC, after some operations (i.g. with gdisk) doesn’t start booting and you are therefore in grub rescue prompt. A very unpleasant situation.

The steps to follow are:

  1. see what are the partitions, with the command ls
    • you should see something like: (hd0)(hd0,msdos1)(hd0,msdos2)(hd1)(hd1,gpt1)
  2. understand what is the right partition to boot (i.g. hd0,gpt2):
    • you can list a single partition to see what it contains, with the command ls (hd0,gpt2). You should be able to see if a partition is the right one.
  3. give the command set prefix=(hd0,gpt2)/boot/grub
  4. give the command set root=(hd0,gpt2)/ root=/dev/sda2 (if the right partition is hd0,gpt2 the name is /dev/sda2, if it was hd1,gpt3 it would be /dev/sdb3)
  5. give the command insmod normal
  6. give the command: normal (or boot)

In this way the system should start with the expected partition.

boot useful tips

  1. It is not necessary to start booting with EFI if you have GPT partitions (you could choose to have legacy boot with GPT partitions).
  2. It is not necessary that EFI partition be at the start of a disk: it could be in every place, provided that it has a) boot (esp) flags, and b) at least 110mb of space.

Flatpak bad installation

It could happen that a flatpak installation, from a link, goes bad and from a GUI you can’t fix the problem. In this case you can try with: sudo flatpak repair in a terminal.

At least, this was my experience with Bottles.