For some reason, when I open files from a unix server on my windows machine, they occasionally have Macintosh EOL conversion, and when I edit/save them again they don\'t wor
That functionality is already built into Notepad++. From the "Edit" menu, select "EOL Conversion" -> "UNIX/OSX Format".
screenshot of the option for even quicker finding (or different language versions)
You can also set the default EOL in notepad++ via "Settings" -> "Preferences" -> "New Document/Default Directory" then select "Unix/OSX" under the Format box.