replace odd line terminator

[Maikel1963]

Hello,
I got some (about a hundred) csv files which include odd line terminators "\r\r\n". For using the files I would like to relace them by "\n" - remove the "\r\r" at end of each line

the regex I want to use goes like: Regex::new(r"(?m)\r\r").unwrap(); but it doesnt find any matches. How do I have to change it?

[BurntSushi]

Please provide an MRE.

[Maikel1963]

I would, but how do I provide a csv here?

[BurntSushi]

If you need help sharing a small Rust program with a short CSV string embedded inside of it, then I'd suggest seeking help in the Rust Community Discord.

The reason why I am insisting on this is because I cannot diagnose your problem from the information given. The regex r"(?m)\r\r" is valid and will find occurrences of \r\r: https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=0acb638cc7baecb7a0ab054428b58185

So I'm forced to conclude that your problem is elsewhere. Hence the request for an MRE. :-)

(Note that (?m) in your regex is strictly superfluous. The m flag only impacts the behavior of ^ and $, and neither ^ nor $ appear anywhere in your regex.)

[Maikel1963]

Thanks for your info and your playground example. When using your csv (even with multiple occurencess of "\r\r\n) it works. It took a while to get the example modified with the original text of one of the csv's. Notepad++ replaces the line endings with correct endings when pasting. But now (replacing directly in the example) the regex doesn't find anything. The reason why I am searchin for "\r\r" is the display of notepad++. There I see this

and here is the link to the modified example.

https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=abbda81b72dee4a27a9c1b8ccb587ae5

Thanks for your help so far

[Maikel1963]

Sorry!
I just realized that Playground also replaces "CR" and "CRLF" by "LF". Under this circumstances the regex cannot find anything, that's clear.
Maybe that is similar in my rust program. I am going to check the data. As long as I am not able to provide proof that the data contains "CRCR" and the regex does not find it, I regard this as answered.

[BurntSushi]

Yes, it's pretty common for various software to automatically normalize newline terminators in various contexts. \r is also weird in that, on Unix at least, it's an escape sequence that will delete preceding text on the same line:

$ echo 'quux\nfoo\rbar'
quux
bar

Notice that foo is missing from the output here.