一、判断结构

if判断结构

if expression; then

command1

command2

fi

if/else判断结构

if expression; then

command

else

command

fi

if/elif/else判读结构

if expression; then

command

elif expression; then

command

elif expression; then

command

fi

case结构

case VAR in

var1) command1 ;;

var2) command2 ;;

*)command ;;

esac

二、循环结构

1、for循环

for variable in(list)

do

command

done

2、类C的for循环

for((expression1;expression2;expression3))

do

command

done

3、while循环

while expression

do

command

done

4、until循环

until expression

do

command

done

5、select循环

select MENU in (list)

do

command

done