Some simple shell script examples

For those who just started to learn shell scripts, it is very important to establish programming thinking. They must be able to express what they need to do in programming, the following are some examples of my learning and collection, which may be helpful to people I have just started to contact.

Evaluate the sum or product of any number. first define the function, the sum and product of any number, then define the variable through the case structure, and call the function.

Hei (){

X = 1

While [$ #-GT 0]

Do

X = 'expr $ x \ * $1'

Shift

Done

Echo $ x

}

He (){

 

 

X = 0

While [$ #-GT 0]

Do

X = 'expr $ x + $1'

Shift

Done

Echo $ x

}

Read-P "+ or *" lx

Case "$ lx" in

"+ ")

He $ *;;

"*")

Hei $ *;;

*)

Echo "no passage ";;

Esac

~

Use Case + function to write a STARTUP script for the source code website service so that you can start, stop, and serve the website service provided by the encoding package in the following way. ()

1 #! /Bin/bash

2 # chkconfig:-85 15

3 # Description: the Apache HTTP Server is an efficient and extensible \

4 # server implementing thecurrent HTTP standards.

5 # processname: httpd

6 start (){

7/user/loacal/httpd/bin/apachectl start

8 Echo "Source httpdrunning... OK"

9 echo

10}

11

12 stop (){

13/usr/local/httpd/bin/apachectl stop

14 echo "Source httpd running... no"

15 echo

16}

17 Status (){

18 netstat-anput | grep: 80 &>/dev/null

19 if [$? -EQ 0]; then

You can view the port and process, or create a folder During Start and Stop, and check whether there are any of the two files.

20 echo "running"

21 esle

22 echo "STOPPED"

23fi

24}

25 case "S1" in

26 "start ")

27 start ;;

28 "stop ")

29 stop ;;

30 "status ")

31 status ;;

32 *)

33 echo "$0 values in START | stop | status"

Esac

 

 

 

Simple shell script, input age and name,

#! /Bin/bash

Read-P "enter your name" Name

Read-P "Enter your age" Age

[! -Z $ name] & Echo "$ name" | echo "You did not enter a name"

[! -Z $ age] & Echo "$ age" | echo "You did not enter age"

 

 

Enter the card number and password,

#! /Bin/bash

Read-P "Enter your card num" Num

Stty-echo

Disable screen output

Read-P "enter your password" passwd

Stty echo

Echo

Echo $ num $ passwd>/tmp/a.txt

Redirect the output content to a.txt

Mail-s "psswd" root </tmp/a.txt

Send a.txt to root with the subject psswd]

 

 

Server_on.sh If a service is not running, start the service. If the service is running and the "service is running" command is executed as follows:

Server_on.sh httpd

Server_on.sh crond

#! /Bin/bash

Service $1 Status &>/dev/null

If [$? -Ne 0];

Then

Service $1 start

Fi

Echo "the service is running"

~

 

Determine the advantages and disadvantages of a student based on the score.

The score is between 1 and 1 ~ Between 100

 

 

In 1 ~ 59 retake

60 ~ 79 Liang

80 ~ 90 excellent

91 ~ 100 rewards

1 #! /Bin/bash

2 read-P "Enter your score" Num

3 if [$ num-ge 1] &>/dev/null & [$ num-Le 100];

(Note: If the input is empty or contains other letters, an error is returned. You can redirect the output to solve this problem)

4 then

5 if [$ num-ge 1] & [$ num-Le 59];

6 then

7 Echo "retake required"

8 Elif [$ num-ge 60] & [$ num-Le 79];

9 then

10 echo "good"

11 Elif [$ num-ge 80] & [$ num-Le 90];

12 then

13 echo "excellent"

14 Elif [$ num-ge 91] & amp; [$ num-Le 100];

15 then

16 echo "rewarded"

17 else

18 "Enter your score range: 1-100"

19fi

20 else

21 echo "Enter your score range: 1-100"

22fi

~

~

 

Add ten system accounts

 

#! /Bin/bash

Name = Zeng

For N in 'seq-W 10'

SEQ-W: Set the width based on the maximum number, for 01 02 10

Do

Useradd $ name $ n

Done

#! /Bin/bash

# Output 21 ~ Number of odd numbers in 57

X = 0

For I in 'seq 21 57'

Do

If ['expr $ I % 2'-Ne 0]; then

Echo $ I

Let X ++

Fi

Done

Echo $ x

 

 

 

 

Output an even number between 1-

 

 

#! /Bin/bash

For N in 'seq 100'

Do

If ['expr $ n % 2'-EQ 0];

Then

Echo $ n

Fi

Done

~

 

 

 

Output 1-20

#! /Bin/bash

I = 20

While [$ I-ge 1]

Do

Echo $ I

Let I --

Done

Echo

~

 

 

Use the while loop output IP address 192.168.4.1-192.168.4.20

#! /Bin/bash

IP = 192.168.4.

I = 20

While [$ I-ge 1]

Do

Echo $ IP $ I

Let I --

Done

Echo

~

 

 

Check whether any host in the 192.168.4.0/24 network segment is online

#! /Bin/bash

IP = 192.168.4.

I = 1

Until [$ I-GT 254]

Do

Ping $ IP $ I

Let I ++

Done

Echo

The above are some shell examples I have collected. I hope this will be helpful to you. If you have any shortcomings, please advise me.

Some simple shell script examples