在变量分配的RHS中引用与不引用变量 [英] Quoting vs not quoting the variable on the RHS of a variable assignment
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问题描述
在shell脚本中,将一个变量分配给另一个变量时,这两者之间有什么区别?
In shell scripting, what is the difference between these two when assigning one variable to another:
a=$b
和
a="$b"
什么时候应该在另一个上使用?
and when should I use one over the other?
推荐答案
我认为这里没有太大区别.是的,建议在引用变量时将其括在双引号中.但是,在您的问题中似乎未引用$x
.
I think there is no big difference here. Yes, it is advisable to enclose a variable in double quotes when that variable is being referenced. However, $x
does not seem to be referenced here in your question.
y=$x
本身并不影响空白的处理方式.只有在实际使用$y
时,引用才有意义.例如:
y=$x
does not by itself affect how whitespaces will be handled. It is only when $y
is actually used that quoting matters. For example:
$ x=" a b "
$ y=$x
$ echo $y
a b
$ echo "$y"
a b
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