shell案例：
- 选择mysql版本
-
在上面的示例中，没有办法在选择了水果后退出，它会一直让我们选择。如果我们希望选择后就退出，则需要在脚本添加 break
-
打印九九乘法表
-
打印三角形（10行10列）
-
循环输出0~10之间的数
选择mysql版本
[root@openEuler ~]# cat select1.sh
#!/bin/bashselect mysql_version in 5.6 5.7 8.0
doecho $mysql_version
done
[root@openEuler ~]# bash select1.sh
1) 5.6
2) 5.7
3) 8.0
#? 2
5.7
#? 3
8.0
#? ^CApple, Banana, Pear, Watermelons, Grape在上面的示例中，没有办法在选择了水果后退出，它会一直让我们选择。如果我们希望选择后就退出，则需要在脚本添加 break
[root@openEuler ~]# cat select2.sh
#!/bin/bashecho "Choose your favorite fruit: "
select fruit in Apple Banana Pear Watermelons Grape
doechoecho "Your favorite fruit is $fruit."break
done[root@openEuler ~]# bash select2.sh
Choose your favorite fruit:
1) Apple
2) Banana
3) Pear
4) Watermelons
5) Grape
#? 3Your favorite fruit is Pear.
[root@openEuler ~]# 打印九九乘法表
[root@openEuler ~]# cat ninetable.sh
#!/bin/bash
for i in `seq 9`
dofor j in `seq 9`do#[ $j -le $i ] && echo -n "$i*$j = `expr $i \* $j` "[ $j -le $i ] && echo -n "$i*$j = `echo $((i*j))` "doneecho " "
done[root@openEuler ~]# bash ninetable.sh
1*1 = 1
2*1 = 2 2*2 = 4
3*1 = 3 3*2 = 6 3*3 = 9
4*1 = 4 4*2 = 8 4*3 = 12 4*4 = 16
5*1 = 5 5*2 = 10 5*3 = 15 5*4 = 20 5*5 = 25
6*1 = 6 6*2 = 12 6*3 = 18 6*4 = 24 6*5 = 30 6*6 = 36
7*1 = 7 7*2 = 14 7*3 = 21 7*4 = 28 7*5 = 35 7*6 = 42 7*7 = 49
8*1 = 8 8*2 = 16 8*3 = 24 8*4 = 32 8*5 = 40 8*6 = 48 8*7 = 56 8*8 = 64
9*1 = 9 9*2 = 18 9*3 = 27 9*4 = 36 9*5 = 45 9*6 = 54 9*7 = 63 9*8 = 72 9*9 = 81打印三角形（10行10列）
[root@openEuler ~]# cat triangle.sh
#!/bin/bashfor i in {1..9}
dofor ((col=1;col<10-i;col++))doecho -n " "donefor ((k=1; k<=i; k++))doecho -n "$i "doneecho " "
done[root@openEuler ~]# bash triangle.sh 1 2 2 3 3 3 4 4 4 4 5 5 5 5 5 6 6 6 6 6 6 7 7 7 7 7 7 7 8 8 8 8 8 8 8 8
9 9 9 9 9 9 9 9 9 循环输出0~10之间的数
[root@openEuler ~]# cat until1.sh
#!/bin/bashi=0#while [ $i -lt 10 ]
#do
# echo $i
# let i++
#doneuntil [ $i -ge 10 ]
doecho $ii=$((i+1))
done
