Archive for the ‘Webtechnology’ Category

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Trouble updating some packages in Ubuntu 22.04, because they are kept back

Tuesday, January 17th, 2023

Maybe you have seen this message more often then before, while updating your computer manually through the terminal:

The following packages have been kept back:
0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.

Historically that could be the case with the classic commands

sudo apt update && sudo apt upgrade

Because that command is careful (doesn’t update) about packages that can introduce dependency conflicts

But that update command has been superseded by

sudo apt update && sudo apt full-upgrade -y

The latter commands also remove packages to resolve dependency conflicts, and in most cases that is everything you want.

But now upgraded to Ubuntu 22.04 I see the kept back message more and more, even when I did a sudo apt update && sudo apt full-upgrade -y

And as it seems, that is absolutely OK, it’s part of the new phased roll-out mechanism. Packages that can break things are introduced in batches. First only a small percentage of users are getting the new version, so if there are bugs, only a small number of people are hit, and the bugs can be fixed before it is introduced on a bigger scale.

How to check if packages are `phased`

apt-cache policy <package-name>

e.g. gnome-remote-desktop

apt-cache policy gnome-remote-desktop 
Installed: 42.4-0ubuntu1
Candidate: 42.7-0ubuntu1
Version table:
42.7-0ubuntu1 500 (phased 0%)
500 jammy-updates/main amd64 Packages
*** 42.4-0ubuntu1 100
100 /var/lib/dpkg/status
42.0-4ubuntu1 500
500 jammy/main amd64 Packages

Just be a little patient. The update will normally come in a few days.

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Find the total size of certain files within a directory tree before deleting them

Friday, January 13th, 2023

Normally I use find, as it is installed by default on any Linux computer or server or terminal I worked with, but lately on my desktop I start using `fdfind` more and more.

Why? Its faster and easier to work with than find.

I really like the user-friendly syntax of `fd` AKA `fd-find` or `fdfind` compared to the classic `find` command.

In Ubuntu the program is installed with `sudo apt install fd-find` and executed as `fdfind`

`fd` uses a regex as the standard search pattern.

Time for some examples.

To find all files in a directory tree that have jpg in their name

Very intuitive and concise.

fdfind jpg

To find all jpg files (extension jpg) in a directory tree

Think I need all files with [e]xtension jpg, the command is again very intuitive:

fdfind -e jpg

To delete all jpg files in a directory tree

Think I need all files with [e]xtension jpg then e[x]ecute a command to delete them [rm], the command is very intuitive:

As the normal delete command in bash is `rm`

fdfind -e jpg -x rm

That’s all.

Another interesting thing to know, what disk-space I’m gonna win by deleting all jpg files.

Find the total size of jpg files within a directory tree (wrongly)

Think: I need all files, and then calculate the filespace of all files.

The normal command of getting a total size of several files is use `du -ch *.jpg` This will list of files and Count a total on the last line. To get just the last line. pipe it to tail, to gets just the last line.

du -ch *.jpg |  tail -1

But du doesn’t work recursive in subdirectory. You can use a trick with globstar, but much easier is it to combine with fd, so you would come to something like this.

fdfind -e jpg -x du -ch | tail -1

But that doesn’t work right, it seems to computes totals for every file, and just show to size of the last result.

Find the total size of jpg files within a directory tree (correctly)

We need the `-X` option here the `execute-batch` command, that runs the command only once on all search results as arguments

fdfind -e jpg -X du -ch | tail -1

Find correctly find the total size of jpg files in a directory and the first level of subdirectories

And with `fdfind` command it’s easy to control Depth, just add a -d option. This will only search in the main and the first subdirectory level.

fdfind -d 2 -e jpg -X du -ch | tail -1

And now you ask yourself. Can I find the size of all jpg files in the third level of subdirectories.

Of course! And easier than you think

Find the total size of jpg files in the third level of subdirectories depth

fdfind --min-depth 4 --max-depth 4 -e jpg -X du -ch | tail -1

See more:

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How to check if you’re running Wayland on Linux

Friday, January 6th, 2023

Wayland is the new display server protocol used by modern Linux installations. It replaces the old X11 protocol. It’s shipping on Ubuntu 22.04 by default.

To check: open a terminal, and echo the `XDG_SESSION_TYPE` variable.


It will output `wayland` or `x11`.

You can still try x11 if you like by selecting that option on login.


This doesn’t work over SSH, it will output: tty

So for that, use this:

loginctl show-session $(loginctl | grep $(whoami) | awk '{print $1}') -p Type | grep wayland

In case Wayland is used it should output:


See more unix.stackexchange

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Firefox and Wayland support on Ubuntu snaps and the user-agent

Friday, January 6th, 2023

Ubuntu 22.04 is shipping with Wayland as the default communication protocol for the display server, replacing the old and X11 (X Window System).

Interestingly although Firefox is supporting Wayland natively, the default stable Firefox snap package doesn’t use it. I is still using XWayland as compatibility layer.

How to check if Firefox is using Wayland or X11?



and search for `Window protocol`

Window Protocol xwayland

That is intentional, see

So what about Firefox Beta? To install Firefox Beta snap next to Firefox stable, see the earlier blog-post Install seperate Fiefox Beta snap.



And search for `Window protocol`

Window Protocol wayland

Note the missing X, that means Wayland is used as the communication protocol.

Why doesn’t show Wayland in the User-Agent header of Linux browsers?

To check the the User-Agent in Firefox Beta, navigate to something like a ip-address checker:

Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/109.0

Although X11 is not used, it still shows X11. I wonder if that is intentional? Probably that is. User-Agent strings are hampered by historical mistakes, like browser-sniffing.

And setting a detailed User-Agent is also a privacy and security risk. Giving to much and unnecessary information about your system. So it is about limiting exposure to browser-fingerprinting.

Be aware this sucks, once you’re aware there is market-power in user-agents. The major players make the rules of the game.

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How to check your CPU is vulnerable for Retbleed?

Friday, December 16th, 2022

On Linux checking for known vulnerabilities is quite easy.

grep -r . /sys/devices/system/cpu/vulnerabilities

On a Zen2 processor¬† you’ll get these results:

/sys/devices/system/cpu/vulnerabilities/spectre_v2:Mitigation: Retpolines, IBPB: conditional, STIBP: always-on, RSB filling, PBRSB-eIBRS: Not affected
/sys/devices/system/cpu/vulnerabilities/itlb_multihit:Not affected
/sys/devices/system/cpu/vulnerabilities/mmio_stale_data:Not affected
/sys/devices/system/cpu/vulnerabilities/mds:Not affected
/sys/devices/system/cpu/vulnerabilities/l1tf:Not affected
/sys/devices/system/cpu/vulnerabilities/spec_store_bypass:Mitigation: Speculative Store Bypass disabled via prctl and seccomp
/sys/devices/system/cpu/vulnerabilities/tsx_async_abort:Not affected
/sys/devices/system/cpu/vulnerabilities/spectre_v1:Mitigation: usercopy/swapgs barriers and __user pointer sanitization
/sys/devices/system/cpu/vulnerabilities/retbleed:Mitigation: untrained return thunk; SMT enabled with STIBP protection
/sys/devices/system/cpu/vulnerabilities/srbds:Not affected
/sys/devices/system/cpu/vulnerabilities/meltdown:Not affected

On a Zen3 processor you’ll get these results:

/sys/devices/system/cpu/vulnerabilities/spectre_v2:Mitigation: Retpolines, IBPB: conditional, IBRS_FW, STIBP: always-on, RSB filling, PBRSB-eIBRS: Not affected
/sys/devices/system/cpu/vulnerabilities/itlb_multihit:Not affected
/sys/devices/system/cpu/vulnerabilities/mmio_stale_data:Not affected
/sys/devices/system/cpu/vulnerabilities/mds:Not affected
/sys/devices/system/cpu/vulnerabilities/l1tf:Not affected
/sys/devices/system/cpu/vulnerabilities/spec_store_bypass:Mitigation: Speculative Store Bypass disabled via prctl and seccomp
/sys/devices/system/cpu/vulnerabilities/tsx_async_abort:Not affected
/sys/devices/system/cpu/vulnerabilities/spectre_v1:Mitigation: usercopy/swapgs barriers and __user pointer sanitization
/sys/devices/system/cpu/vulnerabilities/retbleed:Not affected
/sys/devices/system/cpu/vulnerabilities/srbds:Not affected
/sys/devices/system/cpu/vulnerabilities/meltdown:Not affected

As you can see a Zen2 (Ryzen <5000 series) is vulnerable for Retbleed, why the newer generations are not (Ryzen >=5000 series).

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Fixing the Annoying Pending Update of Snap Store in Ubuntu, get rid of it.

Sunday, September 18th, 2022

Ubuntu is my default OS since Windows XP/MS Explorer crashed to often around 2004, and I’m quite happy with it most of the time. Compared to Windows it is a breath to have and use just open-source software, no more installation, backup, upgrade of hardware or license problems.

You always know that if you buy another computer you can run the same software.

But it’s not only heaven, there are changes and choices made in the infrastructure and they involve wins and losses.

One of the problems I had lately on 20.04LTS is a message that I should update the snap-store app. As it seems the snap-store-app snap is Ubuntu”s new version of the old ubuntu-software package, which on it self is a fork of gnome-software.

Although in Gnome Activities the software program is advertised as Ubuntu-Software, on the command line it is called snap-store. That is confusing. And that cloaking is for a reason I suppose.

Most users aren’t charmed of snaps.

Firefox has moved to snap packaging (+21.10) and in the beginning it was really slow starting and it broke major things like native-messaging for extensions. The latter is still not fixed (both snaps and flatpaks), only in the Firefox Beta channel. (also for Flatpak versions of Firefox)

And AFAICS there is no support for Flatpaks in the snap-store.

That did it.

So I took these bold steps:

sudo snap remove snap-store

sudo apt install --install-suggests gnome-software

Now I have a software app that is call `software` in the Activities and `gnome-software` on the CLI.

It does support debs, snaps and flatpaks.

What do I want more?