嵌套if/then/elseif如何在bash中工作？

Question

语法如何在bash中运行？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"

Answer 1

我想你的问题是关于许多语法中包含的悬浮的其他歧义; 在bash中没有这样的事情.每个if都必须由fi标记if块结尾的伴侣分隔.

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.试图修复一些错误,你可能会得到这样的东西

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