I’m used to windows and I try to find replacement tools in mac world.
I use Notepad++ on Windows and I frequently use the ability to detect and change the charset and the line break mode of a file.

I find some editor who support linebreak changing but I didn’t find an editor that can display the charset of the current file and change it in an other.
Thank you for your help!
Yes: I recommend BBEdit or its free smaller brother TextWrangler. Both are very good and both handle changes to encoding and line breaks etc well.