Linux basic commands-system management

Environment Variable env

Export display = localhost: 0.0 this command modifies the value of display in the environment variable to localhost: 0.0

 

System date

Running timeThis command is used to calculateProgramHow long does it take?

Time gcalctool this command starts a computer process and timing. When the calculator is finished running, the terminal returns the total running time, CPU consumed time, and user consumed time.

Time wget http://www.abc.com/web1/mydoc.doc this command starts a download process and returns all download times after download ends.

 

History command historyThe default number of recent commands is 1000.

History-C this command clears the command information recorded by the system.

 

System Information dmesg

Log file/var/log

 

System running time uptime

 

System User W, WHO, whoami

W and who return the list of users currently logged on to the machine in different forms.

Whoami returns the username used to log on to the current terminal.

 

Logon Information last

Lists previous user logon successes and exits.

CAT/var/log/syslog To view logon Failure Information.