Linux Learning jobs-third week

Content of this week's job:

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] ~]$ who | Sort |cut-d ""-f1 |uniq-c

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

Last |head-n 1|cut-d ""-f1 |id

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

echo $SHELL; env |grep SHELL

4, the third field in the/etc/passwd the value of the largest 10 users of the information is changed to uppercase and saved to the/tmp/maxusers.txt file.

Sort-n-K 3-t ': '/etc/passwd |tail-n |tr A-z >/tmp/etc.conf

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

Ifconfig eth0 |grep ' inet addr ' |awk ' {print $} ' |awk-f ': ' {print $} '

Show eth0 Nic inet addr field, remove both ends, and then remove ":" After a paragraph

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/*.conf | TR A-Z A->/tmp/etc.conf

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

Du-c/var

8. Remove the value of the third field in the/etc/group file to the minimum of 1

Sort-n-K 3-t ': '/etc/group|head-n 10 | Cut-d ":"-f1

Sort by ': ' To arrange the first 10 rows and delete: After a paragraph of characters

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.

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-d-G Distro-u 1005 distro

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

useradd-d/home/linux-u 1100 Megeia

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

Usermod-p mageedu 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-m-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 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;

Passwd-x 3-i Slackware

(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;

Useradd-s/sbin/nologin MySQL

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

echo "123456" | passwd--stdin OpenStack

Linux Learning jobs-third week