Linux basic commands: (4) commands for shutting down and viewing system information

4. Commands for shutting down and viewing system information
(1) Shutdown command: normal shutdown. SHUTDOWN-T 2 2 minutes after the automatic shutdown shutdown-r shutdown after the restart.
(2) Reboot command: Shutdown command, but this command does not write memory or buffer contents back to memory
(3) PS command: Used to view in the computer system, there are those programs are executing and implementation of the situation.
[Ps-u lists the user name and usage time, ps-m lists memory distributions, ps-x lists all programs including those that do not have terminals]
(4) Top command: Can see the current program execution and memory usage, he will update the system status every few seconds to facilitate tracking. Press CTRL + C to exit the program/
(5) Kill command: Kill is used to terminate an executing process. Kill pid[can use the PS command to view the value of a PID]
(6) Data command: Used to set and modify the current time and date.
(7) Cal command: Displays the calendar and calendar, and if you enter the CAL command directly, the current month and calendar will appear. If a year is displayed: Cal 2014. A certain year of the month: RUB; Cal 12 2014