Regex to match each line in a file, with windows and/or linux line break included, even for missing line break at EOF
I think this would work:
.*(\r?\n|$)

.* matches anything except line breaks (at least '\n', but some regex engines also treat other characters as line breaks).
(\r?\n|$) matches the line break or the end of the string (in case the last line is missing a line break.