18 Mar
2016
18 Mar
'16
11:45 p.m.
On Fri, Mar 18, 2016, at 13:12, scj(a)yaccman.com wrote:
It may seem strange to us today, but in the context of
the day, one of
the most radical ideas in Unix was the concept of a file as an array of
bytes, with lines separated by newline characters. Most mainframes had file
systems that were more or less decks of cards on disk
Of course, I assume the answer to the question of why everyone didn't do
that is that there's a trade-off: We take for granted today that you
can't change a line in the middle of a text file without moving
everything after it, either by reading the whole thing into memory and
writing back the changed version, or creating a copy of the file with
the changes and replacing the original with it afterwards, but I assume
these "deck of cards" style files had provisions for editing one in the
middle. You also can't seek to a given line number in a file.