compare two data files?

I guess you didn't read HOW-TO-ASK-A-QUESTION[^]

Are the datas in the files kind of sorted? I mean, if you open both and you go from the beggining, are the "similar" data more or less in order?
In other words, first common data is in line 1 of small file and in line X of big file, then second common data is in line 2 of small file and in line X+Y (placed after the previous) on the big file?

or can these data be without any order? This means 1 common data in line 1 of small file and in line X of second file and second common data in line 2 of small file and in line X-Y (placed before the previous) of the second?

Are the data in different lines? No different lines but separated with any special symbol? Are all lines with the same length? Which kind of data (numbers, strings, structs of mixed formats...)? What do you mean with "rectangular format"? Is like a excell map? Tabulated?


As you see there are a lot of things that can affect directly how the application should work. If you don't give more info, it is hard to help you.