如何从批处理文件输出中插入换行符?
我想做的事情是:
echo hello\nworld
这将输出:
hello
world
如何从批处理文件输出中插入换行符?
我想做的事情是:
echo hello\nworld
这将输出:
hello
world
当前回答
的回声。足够的说。
如果需要在单行中使用&。例如,
echo Line 1 & echo. & echo line 3
输出如下:
Line 1
line 3
现在,假设你想要一些更花哨的东西,……
set n=^&echo.
echo hello %n% world
输出
hello
world
然后当你想在echo语句中添加新行时,只需在其中加入%n%。这更接近于你在各种语言中使用的\n。
分解
Set n=设置变量n等于:
^取消后面的下一个符号:
&表示在同一行上执行另一个命令。我们不关心errorlevel(这是一个echo语句),所以不需要&&。
的回声。继续echo语句。
所有这些都是可行的,因为您实际上可以创建代码变量,并在其他命令中使用它们。它有点像贫民区函数,因为批处理并不是最先进的shell脚本语言。这只是因为批处理对变量的使用很差,没有在int、char、float、字符串等之间自然地进行指定。
如果你很狡猾,你可以让它和其他东西一起工作。例如,使用它来回显一个制表符
set t=^&echo. ::there are spaces up to the double colon
其他回答
的回声。足够的说。
如果需要在单行中使用&。例如,
echo Line 1 & echo. & echo line 3
输出如下:
Line 1
line 3
现在,假设你想要一些更花哨的东西,……
set n=^&echo.
echo hello %n% world
输出
hello
world
然后当你想在echo语句中添加新行时,只需在其中加入%n%。这更接近于你在各种语言中使用的\n。
分解
Set n=设置变量n等于:
^取消后面的下一个符号:
&表示在同一行上执行另一个命令。我们不关心errorlevel(这是一个echo语句),所以不需要&&。
的回声。继续echo语句。
所有这些都是可行的,因为您实际上可以创建代码变量,并在其他命令中使用它们。它有点像贫民区函数,因为批处理并不是最先进的shell脚本语言。这只是因为批处理对变量的使用很差,没有在int、char、float、字符串等之间自然地进行指定。
如果你很狡猾,你可以让它和其他东西一起工作。例如,使用它来回显一个制表符
set t=^&echo. ::there are spaces up to the double colon
如果需要在可以传递给变量的字符串中使用著名的\n,可以编写如下Hello.bat脚本所示的代码:
@echo off
set input=%1
if defined input (
set answer=Hi!\nWhy did you call me a %input%?
) else (
set answer=Hi!\nHow are you?\nWe are friends, you know?\nYou can call me by name.
)
setlocal enableDelayedExpansion
set newline=^
rem Two empty lines above are essential
echo %answer:\n=!newline!%
通过这种方式,多行输出可以在一个地方准备,甚至在其他脚本或外部文件中,并在另一个地方打印。
The line break is held in newline variable. Its value must be substituted after the echo line is expanded so I use setlocal enableDelayedExpansion to enable exclamation signs which expand variables on execution. And the execution substitutes \n with newline contents (look for syntax at help set). We could of course use !newline! while setting the answer but \n is more convenient. It may be passed from outside (try Hello R2\nD2), where nobody knows the name of variable holding the line break (Yes, Hello C3!newline!P0 works the same way).
上面的例子可以细化为子程序或独立批处理,如调用:mlecho Hi\ i 'm your computer:
:mlecho
setlocal enableDelayedExpansion
set text=%*
set nl=^
echo %text:\n=!nl!%
goto:eof
请注意,额外的反斜杠不会阻止脚本解析\n子字符串。
经过一个不眠之夜,在阅读了这里所有的答案后,在阅读了大量的SS64 > CMD和大量的尝试和错误后,我发现:
(几乎)终极解决方案
博士TL;
... 对于早期采用者。
Important! |
---|
Use a text editor for C&P that supports Unicode, e.g. Notepad++! |
设置换行环境变量…
... 在当前CMD会话中
Important! |
---|
Do not edit anything between '= ' and '^ '! (There's a character in between though you don't see it. Neither here nor in edit mode. C&P works here.) |
:: Sets newline variables in the current CMD session
set \n=^&echo:
set nl=^&echo:
... 当前用户
Important! |
---|
Do not edit anything between (the second) '␣ ' and '^ '! (There's a character in between though you don't see it. Neither here nor in edit mode. C&P works here.) |
:: Sets newline variables for the current user [HKEY_CURRENT_USER\Environment]
setx \n ^&echo:
setx nl ^&echo:
... 对于本地机器
Important! |
---|
Do not edit anything between (the second) '␣ ' and '^ '! (There's a character in between though you don't see it. Neither here nor in edit mode. C&P works here.) |
:: Sets newline variables for the local machine [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment]
setx \n ^&echo: /m
setx nl ^&echo: /m
为什么只是快?
它不适用于在同一打印行中没有配对(开引号和闭引号)的双引号,除非唯一未配对的双引号是文本的最后一个字符,例如:
works: ""echo %\n%...after "newline". Before "newline"...%\n%...after "newline" (paired in each printed line) works: echo %\n%...after newline. Before newline...%\n%...after newline" (the only unpaired double-quote is the last character) doesn't work: echo "%\n%...after newline. Before newline...%\n%...after newline" (double-quotes are not paired in the same printed line) Workaround for completely double-quoted texts (inspired by Windows batch: echo without new line): set BEGIN_QUOTE=echo ^| set /p !=""" ... %BEGIN_QUOTE% echo %\n%...after newline. Before newline...%\n%...after newline"
它适用于完全单引号的文本,如:
echo '%\n%...after newline. Before newline...%\n%...after newline'
附加值:转义字符
Note |
---|
There's a character after the '= ' but you don't see it here but in edit mode. C&P works here. |
:: Escape character - useful for color codes when 'echo'ing
:: See https://learn.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences#text-formatting
set ESC=
颜色参见https://imgur.com/a/EuNXEar和https://gist.github.com/gerib/f2562474e7ca0d3cda600366ee4b8a45。
第二个附加价值:轻松获取Unicode字符
通过关键字获取87,461个Unicode字符(AToW)的绝佳页面:https://www.amp-what.com/。
的原因
The version in Ken's answer works apparently (I didn't try it), but is somehow...well...you see: set NLM=^ set NL=^^^%NLM%%NLM%^%NLM%%NLM% The version derived from user2605194's and user287293's answer (without anything between '=' and '^'): set nl=^&echo: set \n=^&echo: works partly but fails with the variable at the beginning of the line to be echoed: > echo %\n%Hello%\n%World! echo & echo:Hello & echo:World! echo is ON. Hello World due to the blank argument to the first echo. All others are more or less invoking three echos explicitely. I like short one-liners.
背后的故事
为了防止set \n=^&echo:在这里的回答中显示空白(并打印其状态),我第一次记住Alt+255用户是在Novell广泛使用网络和使用437和850等代码页的时候。但是0d255/0xFF在现在的Unicode中是大写的大写字母Y。
然后我想起来Unicode中有比普通的0d32/0x20更多的空格,但它们都被认为是空格,并导致与›␣相同的行为。
But there are even more: the zero width spaces and joiners which are not considered as whitespaces. The problem with them is, that you cannot C&P them since with their zero width there's nothing to select. So, I copied one that is close to one of them, the hair space (U+200A) which is right before the zero width space (U+200B) into Notepad++, opened its Hex-Editor plugin, found its bit representation E2 80 8A and changed it to E2 80 8B. Success! I had a non-whitespace character that's not visible in my \n environment variable.
当回显某些内容以重定向到文件时,多个回显命令将不起作用。我认为“>>”重定向器是一个不错的选择:
echo hello > temp echo world >> temp
请注意,所有解决方案使用光标定位根据控制台虚拟终端序列,光标定位与:
Sequence | Code | Description | Behaviour |
---|---|---|---|
ESC [ <n> E | CNL | Cursor Next Line | Cursor down <n> lines from current position |
只有在没有到达控制台窗口底部时才能工作。
在底部没有空间来向下移动光标,所以它只是向左移动(与CRLF的CR),之前打印的行从它的开始被覆盖。