How to use `while read` (Bash) to read the last line in a file if there’s no newline at the end of the file?

Question

Let’s say I have the following Bash script:

while read SCRIPT_SOURCE_LINE; do
  echo \"$SCRIPT_SOURCE_LINE\"
done

I noticed that for files

Answer 1

I use the following construct:

while IFS= read -r LINE || [[ -n "$LINE" ]]; do
    echo "$LINE"
done

It works with pretty much anything except null characters in the input:

• Files that start or end with blank lines
• Lines that start or end with whitespace
• Files that don't have a terminating newline