Re: encryption problem

 James Kanze <>
Sun, 29 Jul 2007 17:14:36 -0000
On Jul 29, 3:50 am, Kai-Uwe Bux <> wrote:

BobR wrote:

Juha Nieminen <nos...@thanks.invalid> wrote in message...

cout << "text: "; // enter some text
cin >> plain_text; file://assign the array of text to plain_text

  Here is the critical point. What happens if the user enters more
than 80 characters?
  You don't want to do that. You want to do this:

std::string plainText;
std::cout << "text: ";
std::getline(std::cin, plainText);

  Now it doesn't matter how much text the user writes. It won't cause
a buffer overflow.

Well, it will:

  plainText.max_size() == 1073741820 [Intel, win98, MinGW].

Not too many people type that much into one line though. <G>
[ at the old (80 char line) x (66 lines per page), thats over200k pages.
So, be sure to tell your users to limit the input to "one book per line=


 :-} ]

No, it won't cause a buffer overflow. Instead, getline() will
stop after max_size() characters and then set the failbit of
the stream. []

Unless, of course, bad_alloc gets thrown before that:-). Or the
machine starts paging so violently that it slows down radically,
and pisses the user off so much that he kills the process.

James Kanze (Gabi Software) email:
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