join

There is a join command, much like the "JOIN" in databases, that enables us to join two files. When it joins the two files together, there needs to be a column in the first file that has the same type of information as a column in the second file. The information within each of these two columns does not need to be in the same order. The join command will put together the contents from the two files in such a way that corresponding rows are joined together.

FIXTHIS we definitely need to put a good example here, demonstrating how to specify the columns. For instance, we could take (say) 50 flights and the corresponding airport addresses, and make a new file. We could even do this twice in a row, to join the origin airports to the titles and addresses of the airports and then again (with a secone application of join) to join the destination airports to the titles and addresses of the airports.