Eight interesting Linux/Unix commands.

This command shows you information about who is logged in.

user@server:$ w

This gathers information about a domain name.

user@server:$ dig domain.com

Query DNS servers for information about domain names

user@server:$ nslookup domain.com

Ancient command to find out more information about DNS

user@server:$ whois domain.com

Find the disk usage of a file or a directory.
(-sh = better readable | -ch = the same but larger output)

user@server:$ du *
user@server:$ du -sh *
user@server:$ du -ch *

Disk freespace, pretty much self explaining but I use it with the -h switch to convert the bytes to megabytes or gigabytes

user@server:$ df
user@server:$ df -h

Find information about users.

user@server:$ finger username

Show who is logged on, and print: time of last system boot, dead processes, system login processes, active processes spawned by init, current runlevel, last system clock change.

user@server:$ who -a
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