bash - 为什么包含\n 的 bash 变量不等于它的副本？

Question

设置后:

var1="a\nb"
var2="$var1"

我希望 $var1 和 $var2 相等；然而:

[[ $var1 == $var2 ]] && echo yes || echo no

返回没有。这是为什么？

Answer 1

您必须引用才能执行字符串比较:

[[ "$var1" == "$var2" ]]

所以这是可行的:

$ var1="a\nb"
$ var2="$var1"
$ [[ "$var1" == "$var2" ]] && echo yes || echo no
yes

为什么会这样？

从评论中，chepner indicates :

Without the quotes, $var2 is interpreted as a pattern, not a string, and the \n is treated as a regular n.