This pair of scripts converts end-lines to Windows or Unix form, in either one file (fixeoln.py) or all text files in a folder tree (fixeoln-all.py). They can be run on any platform, and change only lines that are not in the target format.
See these scripts' docstrings for usage, and for example runs see fixeoln_docetc/fixeoln-test.txt.
The top-level fixeoln-all.py folder-tree walker was added June 2017.