如何在Windows上防止\\ n转换为\\ r \\ n

Question

I am using Windows 10 and Strawberry Perl

It is well know that the line terminator in Linux is \\n , and in Windows is \\r\\n .

I found that, on my computer, files of Linux type will automatically transform to windows type \\r\\n after a replacement operation like

perl -i.bak -pe "s/aaa/bbb/g" test.txt

But this is not what I want, and it seems unreasonable. I would like to know if this is a Strawberry Perl issue, or another factor?

How can I leave the line terminator unaffected on Windows?

Answer 1

This is standard behavior of Perl on Windows (to convert \\n to \\r\\n ).

You can get around it by using binmode , which prevents Perl from doing the automatic line-ending conversion.

Your command would then be changed to look like this. It tells binmode to write to STDOUT and then that output has to be redirected to another file. The following command should do what you want (though not in place):

perl -pe "BEGIN{ binmode(STDOUT) } s/aaa/bbb/g" test.txt > newtest.txt

Answer 2

"Actually I set unix format as notepad++ default which is my main editor" I think you should make the effort the keep files with the correct line endings for the appropriate system. You won't make any friends if you keep Linux files everywhere, as it will make it very hard for others to work with your non-standard methodology

It isn't very hard to work with both systems properly, as all you have to do is to make the change automatically when copying from one system to another. You can use dos2unix and unix2dos when making the copy, but it would be a simple job to write a Perl program to update all of your systems with the relevant version of the text files

However, if you insist on this plan, this should help you to achieve it

By default, when running on Windows, perl will use the IO layers :unix and :crlf , which means it works the same as on a Linux system but will translate CRLF to LF on input, and LF to CRLF on output

You can make individual open calls behave differently by adding an explicit pseudo-layer :raw , which removes the :crlf layer. But if you want to modify the special file handles STDIN , STDOUT and ARGV then you need a different tactic, because those handles are opened for you by perl

You can use the open pragma at the top of your program, like this

use open IO => ':raw';

which will implicitly apply the :raw layer to every input or output file handle, including the special handles. You can set this from the command line by using

perl -Mopen=IO,raw program.pl

Or you can set the PERLIO environment variable

set PERLIO=raw

which will affect every program run henceforth from the same cmd window