cin.ignore() in C

Silly question but I cannot find the answer online..

Is their a C function that does the same as cin.ignore() in C++?

Sombody said it was fflish( stdlin ) but iv heard thats bad...

any info appreicated

Considering that one can actually use cin.get() instead of cin.ignore() in C++ and just ignore what is returned, I would think that one can do the same in C, but with getchar() instead.

If you want it to wait until the user hits enter I do:

Code:

---

while(getchar() != '\n');

---

Quote:

---

Originally Posted by mike_g

If you want it to wait until the user hits enter I do:

Code:

---

while(getchar() != '\n');

---

---

I highly recommend that when coding an empty loop, the semicolon should go on its own line, perhaps with a comment:

Code:

---

while(getchar() != '\n')
    ; /* Empty loop */

---

This makes it clear that you did it intentionally.

check for EOF.

Code:

---

while((getchar() != '\n') && !feof(stdin))
    ; /* Empty loop */

---

Quote:

---

Originally Posted by robwhit

check for EOF.

Code:

---

while((getchar() != '\n') && !feof(stdin))
    ; /* Empty loop */

---

---

Because of the nature of this particular loop, calling feof() like this is okay, but not in general... Don't use this as a general pattern for a read loop.

I don't understand, what's bad about the pattern?

Quote:

---

Originally Posted by robwhit

I don't understand, what's bad about the pattern?

---

Suppose you've just read the last char in the file. You are at the end-of-file. You call feof() and it returns... false! feof() will not return true until a read operation has FAILED while at the end of file. Result? You pass through the loop one time too many.

As I said, in THIS case it doesn't matter, because the loop is empty. In general, controlling an input loop with feof() is not correct.

And there is a details description of why feof shouldn't be used as well in the FAQ. Have a go with the FAQ once.

ssharish2005

No there isn't. (at least not that I'm aware of)

Using getchar() will not work if there is nothing to clear in the buffer -- it will force you to press return an extra time.

Quote:

---

Originally Posted by brewbuck

Suppose you've just read the last char in the file. You are at the end-of-file. You call feof() and it returns... false! feof() will not return true until a read operation has FAILED while at the end of file. Result? You pass through the loop one time too many.

As I said, in THIS case it doesn't matter, because the loop is empty. In general, controlling an input loop with feof() is not correct.

---

this only applies if you have more input in the body and you don't check for EOF, which isn't a problem relating to using feof in the conditional part of the loop, unless it's the only expression in the code.

It isn't bad, but it can be used wrong.