Shulou(Shulou.com)06/02 Report--

1. Count the number of users whose default shell is not / sbin/nologin in the / etc/passwd file, and display all the users.

[root@centos7 ~] # grep-v "/ sbin/nologin" / etc/passwd | wc-l & & grep-v "/ sbin/nologin" / etc/passwd | cut-d ":"-F1

fifteen

Root

Sync

Shutdown

Halt

Rick

Gentoo

Docker

Mongodb

Redis

Tomcat

Nginx

Ric

Mageia

Slackware

Test

[root@centos7 ~] #

2. Find out the user name, UID and shell type of the maximum UID of the user

Method 1:

[root@centos7 ~] # cat / etc/passwd | sort-t:-K3-nr | head-1 | cut-d:-F1 Leng 3 Leng 7

Method 2:

[root@centos7 ~] # cat max_uid.sh

#! / bin/bash

Uid= `cat / etc/passwd | cut-d ":"-f3`

For i in $uid

Do

Max=0

If [$I-gt $max]

Then

Max=$i

Fi

Done

Grep $max / etc/passwd | cut-d ":"-F1

[root@centos7 ~] # sh max_uid.sh

Test:2003:/bin/bash

[root@centos7] # tail-3 / etc/passwd

Mageia:x:1100:1100::/homenux:/bin/bash

Slackware:x:2002:2019::/home/slackware:/bin/tcsh

Test:x:2003:2003::/home/test:/bin/bash

[root@centos7 ~] #

3. Count the number of connections to each remote host IP that is currently connected to this machine, and sort them from large to small

[root@centos7 ~] # ss-tnla | grep ESTAB | tr-s "" | cut-d ""-f5 | sort | uniq-c | sort-nr | head

119 127.0.0.1:3306

40:: ffff:127.0.0.1:3306

21:: ffff:59.39.91.244:3306

4:: ffff:127.0.0.1:60009

2 127.0.0.1:55555

1:: ffff:61.146.78.146:64634

1:: ffff:61.143.130.174:30895

1:: ffff:59.39.91.244:58830

1:: ffff:59.39.91.244:58818

1:: ffff:59.39.91.244:58263

4. Write a script

Createuser.sh to achieve the following functions: use a user name as a parameter, if the user of the specified parameter exists, show its existence, otherwise add it; display information such as the id number of the added user

[root@centos7 ~] # cat createuser.sh

#! / bin/bash

# *

# Author: rickzhu

# QQ: 1779526363

# Date: 2020-02-28

# FileName: createuser.sh

# URL: http://www.magedu.com

# Description: The test script

# Copyright (C): 2020 All rights reserved

# *

If grep $1 / etc/passwd > / dev/null

Then

Echo "$1 is exist."

Else

Useradd $1

Echo "`id $1`"

Fi

[root@centos7 ~] # sh createuser.sh nginx

Nginx is exist.

[root@centos7 ~] # sh createuser.sh test

Uid=2003 (test) gid=2003 (test) groups=2003 (test)

[root@centos7 ~] #

5. Write a script that generates the basic format of the script, including author, contact information, version, time, description, etc.

[root@centos7 ~] # cat createScript.sh

#! / bin/bash

#

# determine whether the current directory has a script with the same name

If ls | grep $1 > > / dev/null

Then

Echo "$1 is exist" & & exit 10

Fi

Cat

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.