whoami
whoami --help
hostname --help | less
date
passwd #for setting a password
su - #switch user, easiest way to switch user.
# the `-` opens a login shell with the full environment of the target user.
# on ubuntu systems su - doesn't work since root doesn't have a password
# The alternative is to use:
su -i
touch #creates an empty file
last #shows last people who logged in
mandb #updates the command database / man database
Which man page to use
man -k <keyword>
man -k user | wc
man -k user | grep 8 | grep create
pinfo coreutils 'whoami invocation'
Getting help
- man
- pinfo
- command --help
- /usr/share/doc