Linux

Fix with: pkill -U $USER pulseaudio

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

In this example we use Ubuntu linux.

Software: mailutils

Restart postfix after changing postfix config file: main.cf: sudo service postfix restart

First test if you can access gmail through port 25: telnet gmail-smtp-in.l.google.com 25

Test mail with: echo "Hello world" | mail -s "Test Email" -a "From: [email protected]" toMail.com

Or: echo "Test from $HOSTNAME" | mail -s "Everything A okay" -a "From: noreply@$HOSTNAME" [destinationmail.com]

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: 

Updating admin user e-mail, when you only have MySQL command line access: UPDATE `wp_users` SET `user_email` = 'INSERT_MAIL' WHERE `ID` = '1';

generate wordpress password for insertion in database: echo -n "password" | md5sum

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

Currently running flutter in ubuntu 20.04.

Flutter cli doc: https://flutter.dev/docs/reference/flutter-cli

Flutter pub doc: https://dart.dev/tools/pub/cmd

KVM installation: sudo apt install qemu-kvm libvirt-daemon-system libvirt-clients bridge-utils virtinst virt-manager
Old info: sudo apt install qemu qemu-kvm virt-manager (Remember to enable VT Virtualization in the Bios) - run: sudo kvm-ok (to check)