循环语句

for…in…do…done

格式

for var in val1 val2 val3
do
    语句1
    语句2
    ...
done

示例：

for i in a 2 cc
do
    echo $i
done
for file in `ls`
do
    echo $file
done
for i in $(seq 1 10)
do
    echo $i
done
for i in {a..z}
do
    echo $i
done

for ((…;…;…)) do…done

格式：

for ((expression; condition; expression))
do
    语句1
    语句2
done

示例：

for ((i=1; i<=10; i++))
do
    echo $i
done

while…do…done

格式：

while condition
do
    语句1
    语句2
    ...
done

示例：

while read name
do
    echo $name
done

until…do…done

格式：

until condition
do
    语句1
    语句2
    ...
done

示例：

until [ "${word}" == "yes" ] || [ "${word}" == "YES" ]
do
    read -p "Please input yes/YES to stop this program: " word
done

死循环的处理方式

如果AC Terminal可以打开该程序，则输入Ctrl+c即可。

否则可以直接关闭进程：
使用top命令找到进程的PID
输入kill -9 PID即可关掉此进程