Third Week Linux blog post

Third Week blog assignment
1. Lists the user names of all logged-in users on the current system, note that the same user logs on multiple times, only once.

W.H.O. | Cut-d '-f1| Sort-u

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

Last | Head-1

3. Removed by the user as their default on the current systemShellThe most of theShell.

CAT/ETC/PASSWD |cut-d ': '-f7 |sort | uniq-c | Sort |head-1

4. Will be/etc/passwdThe number of the third field in the10user's information is all changed to uppercase and saved to/tmp/maxusers.txtfile.

Sort-t ': '-k3-n/etc/passwd |tail-10 |tr [A-z] [a-z] >/tmp/maxusers.txt

5. Remove the current host'sIpaddress, hint: YesIfconfigthe results of the command are sliced.

Ifconfig | grep ' \<inet\> ' | head-1 | Cut-d ': '-f2 |tr-d ' bcast '

6. List/etcall the directories under the. confFile name at the end of the file and convert its name to uppercase after saving to/tmp/etc.conffile.

ls/etc/*.conf | TR[A-Z] [A-z] >/tmp/etc.conf

7. Show/varthe total number of sub-directories or files in the directory.

Ls-a/var/| Wc-l

8. Removed/etc/groupthe number of the third field in the file is the smallest10the name of a group.

Sort-t ': '-k3-n/etc/group | head-10 | Cut-d ': '-f1

9. Will be/etc/fstaband the/etc/issuethe contents of the file are merged into the same content and saved to/tmp/etc.testfile.

Cat/etc/{fstab,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;

Groupadd-g 2016distro

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

Useradd-u 1005-gdistro Mandriva

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

Useradd-u 1100-d/home/linux Mageia

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

echo "Mageedu" | passwd--stdin Mageia

(5) , delete Mandriva, but keep its home directory;

Userdel Mandriva

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

Useradd-u 2002-gdistro-g Peguin Slackware

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

USERMOD-S/BIN/TCSH Slackware

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

Usermod-a-gadmins Slackware

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

PASSWD-N3-X180-W3 Slackware & passwd Slackware

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

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

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

Useradd-s/sbin/nologin-m MySQL

(a) , use the echo command to add a password for OpenStack non-interactively.

echo "PASSWORD" | passwd--stdin OpenStack

Third Week Linux blog post