cal command:
cal output the calendar of the current month
cal -1 is equivalent to cal
cal -3 output the calendar of the previous month, this month, and the next month
cal -y year output the calendar of a certain year
clear command:
clear the results of the commands that have been executed on the terminal (this command does not actually delete the execution results, but is performed on the top Hidden, you can drag the scroll bar to view)
Pipe character “|”:
Pipe character is generally used for special processing, “filter”,’special’,’expanded processing’
auxiliary function Command, not used alone.
For example: list the files containing the letter’y’ in the root directory ls /|prep y
The previous result of the extended processing is the subsequent input For example: view the number of files in the root directory ls /| wc -l
hostname command:
hostname view hostname
hostname -f fully qualified domain name FQDN
id command:
view user’s basic information (including user id, user Group id, additional group id) If this command does not specify a user, it will default to the current user.
id View the basic information of the current user
id Username shows the basic information of the specified user
whoami command:
View Local user name, mostly used for log records.
ps command:
View server process information
ps -ef The c field indicates the CPU occupancy rate. The stime field indicates the process open time. The tty field indicates the terminal device time field indicates the process execution The time cmd represents the name of the process or the corresponding path.
top command:
is mainly used to view the resources occupied by the service process
top enters the dynamic display (refreshed every few seconds)
q exit
du -sh command: du -sh file path to view the real size of the directory -s: summary meaning -h: display the find command in a more readable form: find file path type For example: search the root directory File find / -name *.txt ending in txt For example: search for files/folders in the root directory find / -type f (for files) / d (for folders) service command: is used to control the software’s service startup /Stop/restart service service name start/stop/restart