I have a CSV file that looks like this
AS2345,ASDF1232, Mr. Plain Example, 110 Binary ave.,Atlantis,RI,12345,(999)123-5555,1.56 AS2345,ASDF1232, Mrs. Plain Exampl
With POSIX Awk:
{ c = length m[c] = m[c] ? m[c] RS $0 : $0 } END { for (c in m) print m[c] }
Example