Linux system commands

1. Display the name of the current login WhoAmI or who am I

2. Switch User su

SU user name  or Su-user name    Su-rootsu after add-and no-add-what is the difference?    add-After, not only to switch to other users, but also the environment variables such as switching to other users    do not add-just use this user's permissions, and not use other               

3. Show Memory Status Free

Free-m-S      -M indicates the state in memory in M represents the     time interval, in seconds, that the-s represents the refresh, using: Free-m-S 3

4, Top (similar to the Resource Manager under Windows)

5. Killing Process Kill

Kill  Process number, run the Pkill process name as root,----NOTE: Kill all processes that * process name *

Linux system commands