code for calculating string length

can anybody tell me whats wrong in the following code ::

library ieee,std;
use std.textio.all;
use ieee.std_logic_textio.all;

entity len is
end len;

architecture length of len is
    signal final : integer := 0;
    begin
        process
            file infile : text is in "E:\shweta\extra\RCS card\examples
\data.dat";
            file outfile :text is out "E:\shweta\extra\RCS card
\examples\out.dat";
            variable inlin : line;
            variable outlin : line;
            variable length : integer := 0;
            begin
                while(not(endfile(infile))) loop
                    readline(infile,inlin);
                    wait for 100 ns;
                    length := length + inlin'length;
                    deallocate(inlin);
                end loop;
                final <= length;
        end process;
end length;