Linux

Fix with: pkill -U $USER pulseaudio

(https://bugs.launchpad.net/ubuntu/+source/alsa-lib/+bug/1865499)

Set up Postfix as a secure outbound mail service using an SMTP relay, then test delivery, authentication, DNS, logs, and queue health.

curl tags: https://stackoverflow.com/questions/3074288/get-final-url-after-curl-is…

How to solve CloudFlare protection: https://stackoverflow.com/questions/18500088/curl-load-a-site-with-clou…

PDF

https://blog.joshlemon.com.au/protecting-your-pdf-files-and-metadata/

https://gist.github.com/hubgit/6078384

exiftool -all:all= $FILE ; qpdf --linearize $FILE output.pdf

Images

imagemagick: mogrify -strip NAME_OF_FILE

Test with: exiftool -all NAME_OF_FILE

Default kernel parameters: "quiet splash".

In my opinion you will get more sucessful boots and reduced graphical errors on boot if you remove quit and splash. Specifically the splash screen can make strange things happen and when removing "quiet" you are able to debug if there is an error.

I also tried to fiddel with "/etc/grub.d/48_linux_zfs" where I tried to out comment #vt_handoff="1" and set quiet boot to zero: 

Remove ssl cert: sudo certbot-auto delete 

Quick instructions:

insert: "keycode 49 = less greater backslash backslash backslash" in "$HOME/.Xmodmap" and run "xmodmap .Xmodmap" - this will setup your keys on the system.
To make these keys persistent run: "xkbcomp $DISPLAY $HOME/.xkbmap"

Very interesting: https://medium.com/@saplos123456/persistent-keyboard-mapping-on-ubuntu-using-xmodmap-cd01ad828fcd

If you have the black screen of death when trying to get back from suspend mode, you might want to check out this bug description and possible resolutions: https://bugs.launchpad.net/ubuntu/+source/plasma-desktop/+bug/1849084

Otherwise disable compositor: qdbus org.kde.KWin /Compositor suspend

Check if compositor is enabled: qdbus org.kde.KWin /Compositor org.kde.kwin.Compositing.active
Or: qdbus org.kde.KWin /KWin supportInformation