If you are developing services which need to authenticate each other by mTLS you need a triplet of x509 certificate files: A root CA, client certificates and servers certificates and corresponding key files. One way to generate these files locally is to use openssl, but this is rather tedious as you must configure a lot to use this tool. A more elegant solution is to use the CloudFlare PKI/TLS toolkit....
Sometimes you need to know if a certain file is in a deb package. The easiest way is to use the web frontend for the repositories like debain packages. Another way is to use a tool called apt-file. ...
For my perl jobs i always use perlbrew for setting ip perl environments. Because i am working on multiple projects in multiple perl environment i need so switch the perl envonriments contantly. To see which perl version i am using currently, i made a small extension for the zsh shell. ...