Linux
Linux is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds.
Common Operations
Check DNS of local computerscutil --dns | grep 'nameserver\[[0-9]*\]'
Current OS Release versioncat /etc/*release
Check a Domain dscacheutil -q host -a name example.com
Change Hostname
https://phoenixnap.com/kb/ubuntu-20-04-change-hostname
Ubuntu apt-get complains about unverifiable public key signaturesudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys <KEY>
Change SSH Key Passwordssh-keygen -p -f <keyfile>
e.g. ssh-keygen -p -f ~/.ssh/id_rsa
Change file extension (from .old to .new) recursively inside a folder find ./ -depth -name "*.old" -exec sh -c 'mv "$1" "${1%.t1}.new"' _ {} \;
References
- A thorough, inspiring, simple, and clean Linux Desktop Setup
- 5 Best Practices for Securing SSH
- Bash One-Liners and terminal tricks