for循环格式
代码语言：javascript复制for 变量名 in 变量取值列表
do
指令
done示例 打印5 4 3 2 1 5个数字
代码语言：javascript复制#!/bin/bash
for i in 5 4 3 2 1
do
echo $i
done
方法二
#!/bin/bash
for (( i=5;i>0;i--))
do
echo $i
done PS:改名命令rename命令 jpg格式的图片改成png
代码语言：javascript复制rename ".jpg" ".png" "*.jpg"打印九九乘法表
代码语言：javascript复制#!/bin/bash
for num1 in `seq 9`
do
for num2 in `seq 9`
do
if [ $num1 -ge $num2 ];then
if ((($num1*$num2)>9)) ;then
echo -en "${num1}x${num2}=$((num1*num2)) "
else
echo -en "${num1}x${num2}=$((num1*num2)) "
fi
fi
done
echo " "
done计算1-100的和
代码语言：javascript复制#!/bin/bash
for ((i=1;i<=100;i ))
do
((sum=sum $i))
done
echo "$sum"select循环语句
代码语言：javascript复制select 变量名 [ in 菜单取值列表]
do
指令
done示例:select 循环打印简单菜单项 1、直接使用列表字符串
代码语言：javascript复制#!/bin/bash
select name in zhansan lisi wanger
do
echo $name
done2、采用数组作为变量打印
代码语言：javascript复制#!/bin/bash
array=(zhansan lisi wanger)
select $name in "${array[@]}"
do
echo "$name"
done#!/bin/bash
PS3="please select a num from menu:" #PS3是select循环的提示符
select name in zhansan lisi wanger
do
echo -e "I guess you selected the menu is:n $REPLY) $name" #REPLY变量是菜单项对应的数字
done示例 打印选择菜单 ，选择一键安装不同Web服务
代码语言：javascript复制1.[install lamp]
2.[install lnmp]
3.[exit]#!/bin/bash
RETVAR=0
path=/server/scripts #定义脚本路径
[ ! -d "$path" ] && mkdir $path -p #如果不存在就创建
function Usage() {
echo "Usage :$0 argv"
return 1
}
function InstallService() {
if [ $# -ne 1 ]; then
Usage
fi
local RETVAR=0
echo "start installing ${1}."
sleep 2
if [ ! -x "$path/${1}.sh" ]; then
echo "$path/${1}.sh 没有执行权限"
return 1
else
$path/${1}.sh
return $RETVAR
fi
}
function main() {
PS3="please input the num you want:"
select num in "Install lamp" "Install lnmp" "exit"
do
case "$num" in
"Install lamp")
InstallService lamp
RETVAR=$?
;;
"Install lnmp")
InstallService lnmp
RETVAR=$?
;;
exit)
echo bye.
return 3
;;
*)
echo "the num you input must be {1|2|3}"
echo "Input error"
esac
done
echo $ RETVAR
}
main
