Linux commands by WHO, W, WhoAmI

The WHO, W, and WhoAmI commands can display logged-in user names, but usage and usage effects vary, so let's look at the usage of these three commands and their differences.

1. Who command: Displays user information that is currently logged into the system and does not display the user's login via the SU command:

[email protected] ~]# who

Root Tty1 2015-08-19 16:23

Root pts/0 2015-08-27 01:08 (192.168.1.254)

Root PTS/1 2015-08-27 02:57 (192.168.1.254)

2, W command: The W command is also used to display the user information currently logged into the system, but the W command displays the information more detailed:

[Email protected] ~]# W

03:06:43 up 5:55, 3 users, Load average:0.00, 0.00, 0.00

USER TTY from [email protected] IDLE jcpu PCPU

Root tty1-19aug15 4:22 0.14s 0.14s-bash

Root pts/0 192.168.1.254 01:08 1:28m 0.06s 0.06s-bash

Root pts/1 192.168.1.254 02:57 0.00s 0.09s 0.04s W

3, WhoAmI command: Used to display their own user name, this command is equivalent to "id-un" instructions.

[Email protected] ~]# WhoAmI

Root

[Email protected] ~]# Id-un

Root

Let's take a look at some parameters of these three instructions

Parameters of the WHO command:

1, Who-b//Displays the date and time of the last restart

2. Who-r//Display the current runlevel of the initialization process

3. Add title for each column when who-h//display

4, WHO-M//display only the current running terminal information

5, WHO-Q//statistics on the number of currently logged in users

6. Who-l//Show Login process

7. Who-a//Show All information

Parameters of the W command

1, w-h//Do not display the title

2. W-u//After performing the SU command, the user name is ignored when the current process and CPU time are listed

3, W-s//use short mode. Logon time, JCPU, pcpu time are not displayed

This article is from the "Summer Month" blog, please make sure to keep this source http://lkc0110.blog.51cto.com/3410558/1687605

Linux commands by WHO, W, WhoAmI