UNIX for Dummies Questions & Answers

I am trying to work out how to collate a string in sed.
The format is...
01 R W R D
But i want it to sort like so...
01 RRWD
i have tried regular expressions on this but because their are many different ways this string could appear, it is not working out.
Does anyone know a method of doing this?

What are the different ways the string could appear? It's not clear to me what you're trying to do. Maybe some examples would help.

OK I have a series of strings like this...
01 R W D R
02 W D R R
03 R W R R

But i want it to look like this...
01 R R D W
02 R R D W
03 R R R W

so in other words I want it to place all the R's at the front followed by the D's and then followed by the W's.

So far i have worked out a long winded method of doing this but I'm sure there is a shorter way.
Here is my example...
s/W R/R W/g
s/D R/R D/g
s/W D/D W/g
but this only does this to the line once. is there a method i can make this loop in sed?

Help please

sed isn't a great tool for this problem. I would use ksh:

Code:

#! /usr/bin/ksh
while read number rest ; do
       set $rest
       set -s
       echo $number $@
done
exit 0