Daily tip

I don`t find the firewalld or firewall-cmd tool in Ubuntu!?

These higher level firewall tools are only present in Red hat distros, for Ubuntu or Debian like distribution
please look at ufw documentation.

Daily tip

Can I install Debian on top of another system in a directory (no virtualization)?

See the tool Debootstrap (https://wiki.debian.org/Debootstrap) .

Daily tip

How do I list the content of a Debian package?

$ dpkg –contents <package>


$ dpkg -c <package>

Daily tip

How do I downgrade a package in a Debian distribution?

To revert to the previous version of a Debian type package you follow these steps:

apt-cache show package_name

Then you specify the specific (previous) version you want to downgrade to

apt install packagename=version

Daily tip

How can I verify a package (check for modified configuration files or binaries) in a Debian like distribution (Debian, Ubunut, Mint, etc.)?

#dpkg -V <package_name>