Problem with read in sh

Shell Programming and Scripting
1

I've discovered a very annoying problem in sh:

echo -en "one\ntwo\nthree" | while read VALUE
do
        echo "${VALUE}"
done

This will print one and two, but not three. The last line is IGNORED because it lacks a newline. This makes it hard to use sh for things like CGI scripting; you have to add a newline with sed or something. How can I coerce read into reading the last line?

2

For me it's printing..perfectly.
one
two
three

3

Works in ksh an sh on my box as well.

Do you have IFS set to something wierd?

4

I haven't changed the value of IFS. What version of echo do you have? The version I use implements the '-n' flag, which prevents it from printing the final newline, like so:

 # echo -n "Hello"
hello#

If yours does not have -n, the example won't fail.

I am using GNU bash 3.1.16.

5

Just confirming that this is the behaviour under GNU bash for me also.

I have a question, I'm sure there is a reason you want to do it this way, but why use the -n if piping to another command in the way you describe?

6

It's just an example. The real problem is getting bash to read POST input from the CGI interface, which is fed into stdin and also has no trailing newline. Right now I have to do crazy manipulations with sed and exec. With enough work I can probably find less crazy ways, but all of them involve launching a new process instead of using a builtin, which annoys me to no end.

7

I've discovered part of the reason.

#!/bin/sh

while read LINE
do
        echo "${LINE}"
done

echo "${LINE}"

# echo -en "hello\nworld" | ./readtest.sh
hello
world
#

GNU bash returns error on EOF, even when there was some data. I'll just have to test for empty strings.