I know how to remove all trailing spaces from a file, e.g :
sed -i 's/ *$//' file
Is there a way to do it, but not in lines containing only spaces?
Something in the spirit of :
sed -i 's/[a-zA-Z0-9;}{] *$/[a-zA-Z0-9;}{]/' file
^ keep the original characters
Preferably, but not necessariliy, with sed. Any linux supported solution will do.
Thanks