What happens when I enter EOF while using cin in C++?

Asked Oct 15 '20 at 15:13

Active Oct 15 '20 at 15:50

Viewed 52 times

I entered three inputs to the code below and got the results as follows

(1)

input: CTRL+D

result: (blank)

(2)

input: abcCTRL+D

result: (not terminated yet)

(3)

input: abc

result: abc

using namespace::std;

int main()
{

  string input;

  cin >> input;
  cout << input << endl;
  
  return 0;
}

I wonder why I should enter EOF twice to terminate the code in the second case not just only one time like the first case (it terminated immediately)

edited Oct 15 '20 at 15:50

πάντα ῥεῖ

asked Oct 15 '20 at 15:13

고9마

This behaviour is terminal-specific. AFAIK, some terminals only send EOF if you press Ctrl-D on an empty line. – molbdnilo Oct 15 '20 at 15:24
@πάνταῥεῖ In this question, EOF means ctrl+D, sorry for confussion – 고9마 Oct 15 '20 at 15:38
1

Pro tip: If you want to render keys, you can use `CTRL+D` in the markdown. – πάντα ῥεῖ Oct 15 '20 at 15:38
Hmm, apparently that's no longer possible. Anyways it's clearer like this. – πάντα ῥεῖ Oct 15 '20 at 15:40
@molbdnilo I pressed Ctrl-D after abc in second case. but the program was not terminated immediately. Why this happen? – 고9마 Oct 15 '20 at 15:40
@고9마 As they mentioned, that's terminal specific behavior. – πάντα ῥεῖ Oct 15 '20 at 15:41
@고9마 Probably because of the reason in my first comment. (C++ has nothing to do with it.) You need to consult the documentation for your terminal. – molbdnilo Oct 15 '20 at 15:44
@고9마 Ah, I forgot the exact tag, it's `xxx` – πάντα ῥεῖ Oct 15 '20 at 15:51
Does this answer your question? [Canonical vs. non-canonical terminal input](https://stackoverflow.com/questions/358342/canonical-vs-non-canonical-terminal-input) – Davis Herring Oct 16 '20 at 00:23

What happens when I enter EOF while using cin in C++?

0 Answers0