1. Display the name of the current login whoami or who am i
2. Switch user su
su username or su -username
su -root
What is the difference between adding - and not adding - after su?
After adding -, not only switch to other users, but also switch to other users such as environment variables
Do not add - , only use the permissions of this user, and do not use other
3. Display memory status free
free -m -s
-m indicates that the state in memory is expressed in units of M
-s indicates the refresh interval, in seconds
Usage: free -m -s 3
4. top (similar to the resource manager under windows)
5, kill the process kill
kill process number, run as root pkill process name, ---- note: kill all *process name* processes