Glibc preserves backward compatibility, so if you build against the oldest version you want to support, the resulting binary will work with newer ones.

However that's definitely not what I recommend to do. Better learn packaging and build native packages for distros you are going to support. OBS can make this a bit easier (if your software is FOSS), but any modern CI will also do the job.

Isn't that video stream already compressed? Or you want to convert it using another codec/bitrate?

LOL, all Linux vendors = Red Hat.

All generalizations are false.

It is not steganography. It's just cat original.png trojan > malicious.png.

I don't know, however this is impossible to understand what's wrong with your fonts.

What kind of changes? Package installation, removal and configuration? Use apt-mark showmanual to save list of manually installed packages, dpkg --get-selections | grep 'deinstall$' to save list of removed packages, debconf --get-selections to save debconf package settings, backup files that you edited in /etc. This should be enough for restoration, wouldn't take a long time for backup and avoid risk of filesystem inconsistency.

In what country? There are various national certifications for this purpose.

The standard answer: don't backup the system, automate its deployment instead. Backup only data.

DEL is supposed to delete one row of text

It's not. It overrides a row on a punch card, i. e. one character.

git config core.sshCommand 'ssh -i <path to desired key>'

The biggest problem that I see on this screenshot is that it is a compressed JPEG.

Technically, you always use a username, however in case of Gitlab that SSH username is always git. When an SSH client connects to server, it offers an authentication method. Gitlab accepts that method only if it is a publickey and the fingerprint of the offered key maps to the known Gitlab user.

This is a correct recommendation, however in Debian-based distros you don't need to edit configuration files manually. Just pick some of preinstalled configs. They are installed in /usr/share/fontconfig/conf.avail and symlinked to /etc/fonts/conf.d.

And also show ls -l /etc/fonts/conf.d

No.

It's the same across all POSIX compliant shells. zsh is not POSIX compliant.

touch a b c 'd e f' 'g h i'
for f in *; do ls -la "$f"; done

fxd

Tried using it. Terrible UX. Lots of small annoying things that make the app usage very uncomfortable.

Try to avoid using any file manager (uninstall them all if it is difficult to avoid running them). So you will practice in using file manipulation commands.

All wrong. Original developer of nginx was Igor Sysoev, and his employer who sued him was Rambler.