Why does the following code make my computer beep?

Question

I\'m having a really hard time understanding why is this piece of code making my computer beep. I\'ve isolated this section of code to be the one producing the occasional beep,

Answer 1

The buffer probably contains a '\a' char which makes the computer beep. From 5.2.2 (Character display semantics) :

Alphabetic escape sequences representing nongraphic characters in the execution character set are intended to produce actions on display devices as follows:

• \a (alert) Produces an audible or visible alert without changing the active position.

Answer 2

Agree with the '\a' beep explanation.

One more point about your code:

recvResult = recv(webSocket, buffer, BUFFER_LENGTH, 0);
buffer[recvResult] = '\0';

Note that recvResult will be -1 if there's an I/O error (or if you're working in the non-blocking mode and no data to read so far).

In such a case you'll write into forbidden memory, which is (damn, how I hate this phrase) undefined behavior. Simply speaking - memory overwrite, which is bad.

You should check for socket error before writing into buffer

Answer 3

Nevermind, found it, it was actually the printf statement that was doing an occasionnal beep!