Shell脚本中常用的控制结构

Shell脚本中常用的控制结构

if ... then语句

if [ test_command ]

then

commands

fi

if ... then ... else语句

if [ test_command ]

then

commands

else

commands

fi

if ... then ... elif ... (else)语句

if [ test_command ] then

commands

elif [ test_command ]

then

commands

...

...

else  (optional)

commands

fi

for ... in语句

for 变量 in 变量列表 do

commands

done

while语句

while 条件为真 do

commands

done

until语句

until 条件为真 do

commands

done

case语句

case $variable in match_1)

commands_to_execute_for_1 ;;

match_2)

commands_to_execute_for_2 ;;

match_3)

commands_to_execute_for_3 ;;

...

...

*)  (可选 - any other value)

commands_to_execute_for_no_match

;;

esac