remove-bom.py

from pathlib import Path


ROOT = Path(r"a/b/c/d")
BOM_UTF8 = b"\xEF\xBB\xBF"


def strip_utf8_bom(path: Path) -> bool:
    data = path.read_bytes()
    if not data.startswith(BOM_UTF8):
        return False

    path.write_bytes(data[len(BOM_UTF8):])
    return True


def strip_bom_in_tree(root: Path) -> tuple[int, int]:
    if not root.exists():
        raise FileNotFoundError(root)

    total = 0
    modified = 0

    for cs_file in root.rglob("*.cs"):
        if not cs_file.is_file():
            continue

        total += 1

        try:
            if strip_utf8_bom(cs_file):
                modified += 1
        except OSError:
            pass

    return total, modified


if __name__ == "__main__":
    total, modified = strip_bom_in_tree(ROOT)
    print(f"Scanned: {total}  Modified: {modified}")