string 按换行符拆分bash字符串
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Split bash string by newline characters
提问by sites
I found this.
我找到了这个。
And I am trying this:
我正在尝试这个：
x='some
thing'
y=(${x//\n/})
And I had no luck, I thought it could work with double backslash:
我没有运气，我认为它可以使用双反斜杠：
y=(${x//\n/})
But it did not.
但它没有。
To test I am not getting what I want I am doing:
为了测试我没有得到我想要的我正在做的事情：
echo ${y[1]}
Getting:
获得：
some
thing
Which I want to be:
我想成为：
some
I want yto be an array [some, thing]. How can I do this?
我想y成为一个数组[some, thing]。我怎样才能做到这一点？
回答by Sir Athos
Another way:
其它的办法：
x=$'Some\nstring'
readarray -t y <<<"$x"
Or, if you don't have bash 4, the bash 3.2 equivalent:
或者，如果您没有 bash 4，则 bash 3.2 相当于：
IFS=$'\n' read -rd '' -a y <<<"$x"
You can also do it the way you were initially trying to use:
您也可以按照最初尝试使用的方式进行操作：
y=(${x//$'\n'/ })
This, however, will not function correctly if your string already contains spaces, such as 'line 1\nline 2'. To make it work, you need to restrict the word separator before parsing it:
但是，如果您的字符串已经包含空格，例如'line 1\nline 2'. 要使其工作，您需要在解析之前限制单词分隔符：
IFS=$'\n' y=(${x//$'\n'/ })
...and then, since you are changing the separator, you don't need to convert the \nto spaceanymore, so you can simplify it to:
...然后，由于您正在更改分隔符，您不再需要将 转换\n为space，因此您可以将其简化为：
IFS=$'\n' y=($x)
This approach will function unless$xcontains a matching globbing pattern (such as "*") - in which case it will be replaced by the matched file name(s). The read/readarraymethods require newer bash versions, but work in all cases.
除非$x包含匹配的通配符模式（例如“ *”），否则此方法将起作用- 在这种情况下，它将被匹配的文件名替换。该read/readarray方法需要新的bash版本，但工作在所有情况下。
回答by Fleshgrinder
There is another way if all you want is the text up to the first line feed:
如果你想要的只是第一个换行的文本，还有另一种方法：
x='some
thing'
y=${x%$'\n'*}
After that ywill contain someand nothing else (no line feed).
之后y将包含some而没有其他内容（没有换行符）。
What is happening here?
这里发生了什么？
We perform a parameter expansion substring removal(${PARAMETER%PATTERN}) for the shortest match up to the first ANSI C line feed($'\n') and drop everything that follows (*).
我们对第一个ANSI C 换行符( ) 之前的最短匹配执行参数扩展子字符串删除( ) 并删除( ) 之后的所有内容。${PARAMETER%PATTERN}$'\n'*
