如何在 bash 中“跳出”if 循环？
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how to 'break' out of an if loop in bash?
提问by dominique120
When I use breakin an if loop in bash it tells me its not valid for bash, what can I use instead?
当我break在 bash 的 if 循环中使用时，它告诉我它对 bash 无效，我可以使用什么代替？
The use case is, the user is asked a question and if he answers 'no', the script should skip to the next section.
用例是，用户被问到一个问题，如果他回答“否”，脚本应该跳到下一部分。
if [[ $ans1_1 = "y" ]]; then
fedoraDeps
elif [[ $ans1_1 = "n" ]]; then
break
else
echo "Answer 'y' or 'n' "
fi
回答by ruakh
ifstatements are not "loops", so it doesn't make sense to break out of them. If you want one of your blocks to be a no-op, you can use the built-in :command, which simply does nothing:
if语句不是“循环”，因此脱离它们是没有意义的。如果你希望你的一个块是空操作，你可以使用内置:命令，它什么都不做：
if [[ $ans1_1 = y ]]; then
fedoraDeps
elif [[ $ans1_1 = n ]]; then
:
else
echo "Answer 'y' or 'n'"
fi
回答by John B
For this example, I think it makes more sense to use case.
对于这个例子，我认为使用case.
case $ans1_1 in
y)fedoraDeps;;
n);;
*) echo "Answer 'y' or 'n'";;
esac
From man bash:
来自man bash：
If the ;; operator is used, no subsequent matches are attempted after the first pattern match.
如果;; 使用运算符，在第一个模式匹配后不会尝试后续匹配。
回答by DopeGhoti
This sounds like an ideal case for the selectcommand:
这听起来像是select命令的理想情况：
PS3="Please make a selection >"
select foo in 'y' 'n'; do
case $foo in
'Y')
fedoraDeps
;;
'y')
fedoraDeps
;;
'n')
break
;;
esac
done
回答by Coder-guy
I agree that case is probably best. But you should probably cast to upper/lower case either way. For the way you had it:
我同意这种情况可能是最好的。但是您可能应该以任何一种方式转换为大写/小写。对于你的方式：
if [[ ${ans1_1,,} = "y" ]]; then
fedoraDeps
elif [[ ${ans1_1,,} = "n" ]]; then
:
else
echo "Answer 'y' or 'n' "
fi
Or, if you wanted uppercase ${ans1_1^^}
或者，如果您想要大写 ${ans1_1^^}
