Linux "echo -n" not being flushed

Question

I have the following code:

while ...
  echo -n "some text"
done | while read; do
  echo "$REPLY" >> file
done

but echo works only when used without "-n" flag. looks like when using -n, the output is not flushed/read by next while loop

How can I make sure that "some text" will be read even when not followed by EOL?

Answer 1

You can't distinguish between

echo -n "some text"

and

echo -n "some t"
echo -n "ext"

so you need some kind of delimiting rule. Usually EOL is used for that. read supports custom delimiter via -d or can split based on number of chars via -n or -N. For example you can make read fire on each symbol:

echo -n qwe | while read -N 1 ch; do echo $ch; done

Answer 2

The workaround would be (following original example):

while ...
  echo -n "some text"
done | (cat && echo) | while read; do 
  echo "$REPLY" >> file
done

This will append EOL to the test stream & allow read to read it. The side effect will be an additional EOL at the end of stream.