#!/bin/bash
foo
=
' HELLO \
REDANT=${M45234}${CM_D33D}C \
MOREF=${C333M_V453451}${C33M_ERJE}'
echo
"
$foo
"
|
sed
-r
'{ :s; s/( )? *\\ *$/\1/; Te; N; bs; :e; s/\n//g }'