嵌套if / then / else如果在bash中工作?

时间:2013-03-10 21:37:36

标签: linux bash nested if-statement

bash中的语法如何工作?这是我的C style if if语句的伪代码。例如:

If (condition)
    then
    echo "do this stuff"

elseif (condition)
    echo "do this stuff"

elseif (condition)
    echo "do this stuff"

    if(condition)
        then
        echo "this is nested inside"
    else
        echo "this is nested inside"

else
    echo "not nested"

1 个答案:

答案 0 :(得分:34)

我猜你的问题是关于许多语法中包含的悬殊的歧义;在bash中没有这样的事情。每个if都必须由标记if块结尾的伴随fi分隔。

鉴于此事实(除了其他语法错误),您会注意到您的示例不是有效的bash脚本。试图解决一些你可能得到的错误

if condition
    then
    echo "do this stuff"

elif condition
    then
    echo "do this stuff"

elif condition
    then
    echo "do this stuff"
    if condition
        then
        echo "this is nested inside"
    # this else _without_ any ambiguity binds to the if directly above as there was
    # no fi colosing the inner block
    else
        echo "this is nested inside"

    #   else
    #       echo "not nested"
    #  as given in your example is syntactically not correct !
    #  We have to close the  last if block first as there's only one else allowed in any block.
   fi
# now we can add your else ..
else
   echo "not nested"
# ... which should be followed by another fi
fi