Add a newline only if it doesn't exist

Question

I want to add a newline at the end of a file only if it doesn\'t exists, this is to prevent multiple newlines at the end of the file.

I\'m hoping to use sed. Here\'s the

Answer 1

Since it removes newline if it's not there, you could simply use:

echo "" >> file;  sed -ie '/^$/d;$G' file; sed -ie '/^$/d;$G' file

Adds a newline and removes everything then adds newline. Not the elegant way, but certainly works :)

Answer 2

Try using vi or ex:

ex -scwq foo.txt

or for multiple files:

vi -es +"bufdo wq" *.txt
ex -s +"bufdo wq" *.txt

which automatically adds EOL at EOF on file save if it's missing.

To apply for certain files recursively, use a new globbing option (**) such as **/*.txt (enable by shopt -s globstar).