Linux Jobs (iii)

1. List the user name of all logged-in users on the current system, note: The same user logged in multiple times, only once.

[Email protected] desktop]# who

Xu Tty5 2016-08-21 23:20

Root tty1 2016-08-21 23:12 (: 0)

Root pts/0 2016-08-21 23:13 (: 0.0)

[Email protected] Desktop]# who | Cut-d '-f1 |sort-u

Root

Xu

2. Remove the information about the user who last logged in to the current system.

[[Email protected] Desktop]# last | Head-1

Xu Tty5 Sun 23:20 still logged in

3. Remove the shell that is the user's default shell on the current system.

[[Email protected] Desktop]# cat/etc/passwd| Cut-d ': '-f7 | uniq-c | Sort-n | Tail-1 | Cut-d '-f7

4, the information of the third field in/ETC/PASSW D with the largest number of the first 10 users is changed to uppercase and then saved to the/tmp/maxusers.txt file.

SORT-T:-k3-n/etc/passwd | tail-10 | TR "A-Z" "A-Z" >/tmp/maxusers.txt

5, take out the IP address of the current host, hint: The result of ifconfig command is sliced.

Ifconfig | grep ' inet addr: ' |cut-d:-f2|cut-d '-f1

6. List the file names of all files ending with. conf in/etc directory and convert their names to uppercase and save them to the/tmp/etc.conf file.

ls/etc | grep '. conf$ ' | Tr ' A-Z ' A-Z ' >/tmp/etc.conf

7. Displays the total number of sub-directories or files in the/var directory.

[Email protected] ~]# Ls/var |wc-w

21st

8. Remove the names of the 10 groups with the smallest number of the third field in the/etc/group file.

[Email protected] ~]# cat/etc/group |sort-t:-n-k3|head-10|cut-d:-f1

Root

Bin

Daemon

Sys

cd/

Tty

Disk

Lp

Mem

Kmem

9, the contents of the/etc/fstab and/etc/issue files are merged into the same content and saved to the/tmp/etc.test file.

[Email protected] ~]# cat/etc/fstab/etc/issue >/tmp/etc.test

10. Summarize the methods used to describe the user and group management commands and complete the following exercises:

(1), create group distro, its GID is 2016;

Groupadd-g distro

(2), create user Mandriva, whose ID number is 1005; basic group is distro;

Useradd-u 1005 mandriva-g distro

(3), create user Mageia, whose ID number is 1100, home directory is/home/linux;

Useradd-u 1100 mageia-d/home/linux Mageia

(4), to the user mageia add password, password for mageedu;

echo "Password" | passwd--stdin Mageia

(5), delete Mandriva, but retain their home directory;

Userdel Mandriva

(6), create user Slackware, its ID number is 2002, the basic group is distro, additional group Peguin;

Useradd-u 2002-g distro-g Peguin Slackware

(7), modify the Slackware default shell for/BIN/TCSH;

Usermod-s/bin/tcsh Slackware

(8), add additional Group admins for user Slackware;

Usermod-g-A admins Slackware

(9), add password for Slackware, and require the minimum password age of 3 days, the maximum is 180 days, warning for 3 days;

echo "Magejiaoyu" |passwd--stdin slackware-n 3-x 180-w 3

(10), add user OpenStack, whose ID number is 3003, the basic group is clouds, the additional group is Peguin and Nova;

Useradd-u 3003-g clouds-g Peguin,nova OpenStack

(11), add the system user MySQL, request its shell for/sbin/nologin;

[[email protected] tmp]# useradd-r-s/sbin/nologin MySQL

(12), use the echo command, non-interactive add a password for OpenStack.

echo "passwd" | passwd--stdin OpenStack

This article is from the "Operations Learning" blog, please be sure to keep this source http://yujing.blog.51cto.com/7404589/1840939

Linux Jobs (iii)