Shell 基础知识 04 流程控制

1. if 语句

if condition1
then
  command1
elif condition2
then
  command2
else
  command3
fi

2. for 语句

for var in item1, item2, ..., itemN
do
  command1
  command2
  ...
  commandN
done

3. while 语句

while condition
do
  command
done

4. 无限循环的两个写法

while true
do
  command
done

for (( ; ; ))

5. until 语句

a=0
until condition
do
  command
done

6. case 语句

case val in
  val1)
  command11
  command12
  ;;
  val2)
  command21
  command22
  ;;
esac

7. break/continue 语句

#!/bin/bash
while:
do
    echo -n "输入 1 到 5 之间的数字: "
    read aNum
    case $aNum in
        1|2|3|4|5) echo "你输入的数字为 $aNum!"
        ;;
        6|7|8|9|10) echo "你输入的数字为 $aNum!"
            break
        ;;
        *) echo "你输入的数字不是 1 到 5 之间的!"
            continue
            echo "游戏结束"
        ;;
        6
    esac
done