Re: right justify each line?

Ruud, you're right, you figured out the shortest solution, and it does 
not require knowledge of the line length. Again using dashes instead of 
blanks, my original simple-minded attempt does NOT work, \1 is greedy 
and eats up the entire line, so \2 is always empty.

$ cat input.txt
9----
----9
--9--
-9-9-
--9-9
9-9--
-----
99999

$ sed -r 's/^(.*)(-*)$/\2\1/' input.txt
9----
----9
--9--
-9-9-
--9-9
9-9--
-----
99999

Your solution does work, because you stop \1 from being so greedy. [^-] 
stops \1 from eating up the entire line, so \2 takes the trailing spaces 
(dashes here), which get moved to the front, just as you said.

$ sed -r 's/^(.*[^-])(-*)$/\2\1/' input.txt
----9
----9
----9
--9-9
--9-9
--9-9
-----
99999

I did slightly modify your solution, adding needed anchor '$' to correct 
a glitch processing line 5 in the test case above.

Thanks,
Daniel

On 11/15/2015 6:33 AM, 'Ruud H.G. van Tol' [sed-users] wrote:
>
>   > $ cat input.x
>   > 99---
>   > ---99
>   > -9---
>   > -9-9-
>   > 99999
>
> As was suggested before, if all lines have the right number of trailing
> spaces, then just move those to the front.
>
> sed 's~^\(.*[^ ]\)\(  *\)~\2\1~' input.txt
>
> -- Ruud
>
>
> ------------------------------------
> Posted by: "Ruud H.G. van Tol"
> ------------------------------------
>