1、测试1 求1-100的和
[root@centos7 test2]# cat test.sh #!/bin/bash sum=0 a=1
while [ $a -le 100 ] do let sum+=$a let a++ done echo "the sum of 1-100 is: $sum" [root@centos7 test2]# bash test.sh the sum of 1-100 is: 5050
2、用户输入决定程序循环的次数
[root@centos7 test2]# cat test.sh #!/bin/bash read -p "please input your choise: " choise while [ $choise != q ] do read -p "input an number: " number tmp=$(expr $number % 2) if [ $tmp -eq 0 ] then echo "even!"
else echo "odd" fi echo "choose to continue or quit. q: quit; other:continue!" read -p "please input your choise: " choise done [root@centos7 test2]# bash test.sh please input your choise: e input an number: 8 even! choose to continue or quit. q: quit; other:continue! please input your choise: y input an number: 7 odd choose to continue or quit. q: quit; other:continue! please input your choise: q
3、编写程序 每隔10秒显示系统负载、内存信息
[root@centos7 test2]# cat test.sh #!/bin/bash while true
do uptime free -h echo "____________________________________________________________________________________________________" sleep 10 done
4、结合read语句逐行读取数据
[root@centos7 test2]# cat test.sh #!/bin/bash seq 50 | while read i do tmp=$(expr $i % 5) if [ $tmp -eq 0 ] then echo "$i" fi done [root@centos7 test2]# bash test.sh 5
10
15
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25
30
35
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45
50
继续
[root@centos7 test2]# cat a.txt 4 8
2 5
1 4
6 3
3 2 [root@centos7 test2]# cat test.sh #!/bin/bash cat a.txt|while read i do a=$(echo $i | cut -d " " -f 1) b=$(echo $i | cut -d " " -f 2) c=$(expr $a \* $b) echo "$c" done [root@centos7 test2]# bash test.sh 32
10
4
18
6