Normally I do most of my network programming in Java; life is just easier that way. But some times, *very* rarely, you need to carve up a little C. So I’ve not touched socket networking for a while and all its foibles. Hence a few problems with reading from a socket.
When socket programming with the ‘read’ function it does not always return the length read into the buffer. In fact if you are talking to an HTTP server a ‘GET /‘ will nearly always end with read returning 0. This is because the socket will have been closed on your last read. This of course begs the question, how do you know how much was read in the last read? For me this was simple; I just zero filled the buffer prior to reading.
ssize_t r_read(int sock, void* buf, size_t size)
{
ssize_t ret;
bzero(buf, size);
while (ret = read(sock, buf, size - 1), ret == -1 && errno == EINTR);
return ret;
}
Which does work because now its a simple matter of counting until the first 0 shows up, but I’d still like to know how to tell how many characters were read without having to do the count. This becomes more important when transferring binary files as you won’t know if the 0 is validly part of the file or not.