shell 循环

while循环，条件为真时执行

i=0
while [ $i -lt 10 ]
do
    echo $i
    let i++
done

until循环，条件为假时执行

i=0
until [ ! $i -lt 10 ]
do

    echo $i
    let i++
done

case循环

echo "php|apache|mysql"
echo "输入你的选择:"
read choice
case $choice in
    php) echo "你选择的是$choice"
    ;;
    apache) echo "你选择的是$choice"
    ;;
    mysql) echo "你选择的是$choice"
    ;;
esac

select

select system in "centos" "redhat" "ubuntu"
do
    echo "you system is:" $system
done