Linux - check if there is an empty line at the end of a file [duplicate]

Question

NOTE: this question used to be worded differently, using “with/out newline” instead of “with/out empty line”

I have two files, one with an empty line and one without:

File: text_without_empty_line

$root@kali:/home#cat text_without_empty_line
This is a Testfile
This file does not contain an empty line at the end
$root@kali:/home#

File: text_with_empty_line

$root@kali:/home#cat text_with_empty_line
This is a Testfile
This file does contain an empty line at the end

$root@kali:/home#

Is there a command or function to check if a file has an empty line at the end? I already found this solution, but it does not work for me. (EDIT: IGNORE: A solution with preg_match and PHP would be fine as well.)

Answer 1

Just type:

cat -e nameofyourfile

If there is a newline it will end with $ symbol. If not, it will end with a % symbol.

Answer 2

Olivier Pirson's answer is neater than the one I posted here originally (it also handles empty files correctly). I edited my solution to match his.

In bash:

newline_at_eof()
{
    if [[ -s "$1" && -z "$(tail -c 1 "$1")" ]]
    then
        echo "Newline at end of file!"
    else
        echo "No newline at end of file!"
    fi
}

As a shell script that you can call (paste it into a file, chmod +x <filename> to make it executable):

#!/bin/bash
if [[ -s "$1" && -z "$(tail -c 1 "$1")" ]]
then
    echo "Newline at end of file!"
else
    echo "No newline at end of file!"
fi