8 useful shell-script sharing

This article mainly introduced 8 practical shell script sharing, this article has given the judgment input number character, the character or other, asks the average, the self decrement output, adds the prefix in the file, the batch test file existence and so on the practical script, needs the friend may refer to under

A few examples of shell scripts, it feels good.

"Example: 001" to judge the input as a number, character or other

The code is as follows:

#!/bin/bash

Read-p "Enter a number or string here:" Input

Case $input in

[0-9]) echo-e "Good job, Your input is a numberic! n ";;

[A-za-z]) Echo-e "Good job, Your input is a character! n ";;

*) echo-e "Your input is wrong, input again! n ";;

Esac

"Example: 002" asking for an average

The code is as follows:

#!/bin/bash

# Calculate The average of a series of numbers.

Score= "0"

Average= "0"

sum= "0"

num= "0"

While true; Todo

Echo-n "Enter your score [0-100%] (' Q ' for quit):"; Read SCORE;

if (("$SCORE" < "0")) | | (("$SCORE" > "100")); Then

echo "be serious." Common, try again: "

elif ["$SCORE" = = "Q"]; Then

echo "Average rating: $AVERAGE%."

Break

Else

sum=$[$SUM + $SCORE]

num=$[$NUM + 1]

average=$[$SUM/$NUM]

Fi

Done

echo "Exiting."

"Example: 003" self-minus output

The code is as follows:

[Scriptname:doit.sh]

while (($# > 0))

Todo

Echo $*

Shift

Done

/>./doit.sh a b c d E

A b c d E

b c D E

C d E

D E

E

"Example: 004" Add a prefix to a file

The code is as follows:

# List of names

# Cat NameList

Jame

Bob

Tom

Jerry

Sherry

Alice

John

# Script Program

# Cat Namelist.sh

#!/bin/bash

For name in $ (cat namelist)

Todo

echo "Name=" $name

Done

echo "The name is out of namelist file"

# Output Results

#./namelist.sh

Name= Jame

Name= Bob

Name=, Tom.

Name= Jerry.

Name= Sherry

Name= Alice

Name= John

"Example: 005" Does the bulk test file exist

The code is as follows:

[Root@host ~]# Cat testfile.sh

#!/bin/bash

For file in test*.sh

Todo

If [f $file];then

echo "$file existed."

Fi

Done

[Root@host ~]#./testfile.sh

Test.sh existed.

Test1.sh existed.

Test2.sh existed.

Test3.sh existed.

Test4.sh existed.

Test5.sh existed.

Test78.sh existed.

Test_dev_null.sh existed.

Testfile.sh existed.

Example: 005 populating the hard disk with the specified size file

The code is as follows:

[Root@host ~]# Df-ih/tmp

FileSystem inodes iused ifree iuse% mounted on

/dev/mapper/vg00-lvol5

1000K 3.8K 997K 1%/tmp

[Root@host ~]# Cat cover_disk.sh

#!/bin/env Bash

Counter=0

max=3800

Remainder=0

While True

Todo

((counter=counter+1))

If [${#counter}-gt $max];then

Break

Fi

((remainder=counter%1000))

If [$remainder-eq 0];then

Echo-e "counter= $countertdate =" $ (date)

Fi

Mkdir-p/tmp/temp

Cat < Testfile > "/tmp/temp/myfile. $counter"

If [$?-ne 0];then

echo "Failed to write file to Disk."

Exit 1

Fi

Done

echo "done!"

[Root@host ~]#./cover_disk.sh

counter=1000 date= Wed Sep 09:20:39 HKT 2014

counter=2000 date= Wed Sep 09:20:48 HKT 2014

counter=3000 date= Wed Sep 09:20:56 HKT 2014

Cat:write error:no spaces left on device

Failed to write file to Disk.

DD If=/dev/zero of=testfile bs=1m count=1

"Example: 006" reads a configuration file by traversing the method

The code is as follows:

[Root@host ~]# Cat Hosts.allow

127.0.0.1

127.0.0.2

127.0.0.3

127.0.0.4

127.0.0.5

127.0.0.6

127.0.0.7

127.0.0.8

127.0.0.9

[Root@host ~]# Cat readlines.sh

#!/bin/env Bash

I=0

While Read Line;do

hosts_allow[$i]= $LINE

((i++))

Done < Hosts.allow

For ((i=1;i<=${#hosts_allow [@]};i++)); Todo

echo ${hosts_allow[$i]}

Done

echo "Done"

[Root@host ~]#./readlines.sh

127.0.0.2

127.0.0.3

127.0.0.4

127.0.0.5

127.0.0.6

127.0.0.7

127.0.0.8

127.0.0.9

Done

"Example: 007" Application of simple regular expressions

The code is as follows:

[Root@host ~]# Cat regex.sh

#!/bin/env SH

#Filename: regex.sh

Regex= "[A-za-z0-9]{6}"

if [[$ =~ $regex]]

Then

Num=$1

Echo $num

Else

echo "Invalid Entry"

Exit 1

Fi

[Root@host ~]#./regex.sh 123abc

123abc

#!/bin/env Bash

#Filename: validint.sh

Validint () {

Ret= ' echo $ | awk ' {start = match ($1,/^-?[ 0-9]+$/); if (start = = 0) print "1"; else print "0"} '

Return $ret

}

Validint $

If [$?-ne 0]; Then

echo "Wrong Entry"

Exit 1

Else

echo "ok! Input number is: "$

Fi

"Example: 008" Simple backup files by date

The code is as follows:

#!/bin/bash

now=$ (date + "%m-%d-%y") # Current date

File= "Backup. $NOW. tar.gz" # Back up files

echo "Backing up data to/tmp/backup. $NOW. tar.gz file, please wait ..." #打印信息

Tar xcvf/tmp/backup. $NOW. tar.gz/home//etc//var # Simultaneously back up multiple files to the specified tar compressed file

echo "Done ..."