Trailing newlines and the bash 'read' builtin
If you want the above loop to process the incomplete line, do this:
echo -n $'a\nb\nc' | while read x || [[ $x ]]; do echo = $x =; donewhich gives:
= a == b == c =When read encounters the incomplete line, it does read that into the variable (x in this case) but returns a non-zero exit code which would end the loop, and || [[ $x ]] takes care of running the loop for the incomplete line as well. When read is called the next time, there is nothing to read and it exits with 1, setting x to an empty string as well, which ensures that we end the loop.
Related
$ man bash read [-ers] [-a aname] [-d delim] [-i text] [-n nchars] [-N nchars] [-p prompt] [-t timeout] [-u fd] [name ...] One line is read from the standard input, ...I think the key is: How to define "One line".
Does text without a '\n' at the end makes One line?
I guess read don't think so.