Replace newlines with literal \n

Question

This stackoverflow question has an answer to replace newlines with sed, using the format sed \':a;N;$!ba;s/\\n/ /g\'.

This works, but not for special characters like

Answer 1

You could do this using sed and tr:

sed 's/$/\\n/' file | tr -d '\n'

However this will add an extra \n at the end.