A few examples of shell scripts, it feels good.
"Example: 001" to judge the input as a number, character or other
Copy Code code as follows:
#!/bin/bash
Read-p "Enter a number or string here:" Input
Case $input in
[0-9]) echo-e "Good job, Your input is a numberic! \ n ";;
[A-za-z]) Echo-e "Good job, Your input is a character! \ n ";;
*) echo-e "Your input is wrong, input again! \ n ";;
Esac
"Example: 002" asking for an average
Copy Code code as follows:
#!/bin/bash
# Calculate The average of a series of numbers.
Score= "0"
Average= "0"
sum= "0"
num= "0"
While true; Todo
Echo-n "Enter your score [0-100%] (' Q ' for quit):"; Read SCORE;
if (("$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
Copy Code code 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
Copy Code code 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
Copy Code code 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
Copy Code code 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= $counter \tdate=" $ (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
Copy Code code 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
Copy Code code 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
Copy Code code 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 ..."
