Compare files line by line

-- adding new data to UserNav.dat

-- read user_nav.dat
user_nav_dat = TextFile.ReadToTable("%UserNav%");

-- read earth_nav11.txt
earth_nav11_txt = TextFile.ReadToTable("%TempFolder%\\earth_nav11.txt");
-- setting variables
lines_table = {};
inc = -1;

-- remove any line from dat which exists in txt
-- search the dat file for any line in the txt file
for line_number_dat,line_content_dat in pairs(user_nav_dat) do
    for line_number_txt,line_content_txt in pairs(earth_nav11_txt) do
        -- skip empty strings
        if (String.TrimRight(String.TrimLeft(line_number_dat, " "), " ") ~= "" or String.TrimRight(String.TrimLeft(line_content_txt, " "), " ") ~= "") then
            -- compare the two strings
            if (String.TrimRight(String.TrimLeft(line_content_dat, " "), " ") == String.TrimRight(String.TrimLeft(line_content_txt, " "), " ")) then
                -- entry found, put the line number in an array so we can remove it later
                inc = inc + 1;
                line_number_dat_new = line_number_dat - inc;
                Table.Insert(lines_table, 1, line_number_dat_new);
            end
        end
    end
end

-- Remove the lines from user_nav.dat
Table.Sort(lines_table, nil)
for x,y in pairs(lines_table) do
    Table.Remove(user_nav_dat, y);
end