See linux file management from the who command

From the who command, we can see that the file management in linux is probably started from the linux command "who". man explained the "who" command to print the information of the current user www.2cto.com. the first column of the result on the computer is the user name, the second column is the login port ,...
From the who command, we can see that the file management in linux is probably started from the linux command "who". man explained the "who" command to print the information of the current user www.2cto.com. results on the computer
The first column is the user name, the second column is the login port, and the second column is the login time. the two lines indicate that the user's login information is stored in utmp in two places. which command can be implemented in this way, read the content in utmp, display the record, and close utmp. here we use the linux idea that everything is a file. The who command is a simple embodiment. open the file, save the file id and read the user's login information based on the file id, which is displayed on the terminal.