About setsockopt () and getsockopt ()

Question

Why are socket options ie setsockopt () and getsockopt () used in socket programming?

Answer 1

For example, you want to set or find out the size of the receive buffer

1)

int skt, int sndsize;
err = setsockopt(skt, SOL_SOCKET, SO_RCVBUF, (char *)&sndsize,
                                 (int)sizeof(sndsize));

err = getsockopt(skt, SOL_SOCKET, SO_RCVBUF, (char *)&sockbufsize, &size);

2) Reuse address

 int on = 1;
 if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)

Answer 2

As already mentioned, they are used to set / get various options for the socket.

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Answer 3

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int getsockopt(int sockfd, int level, int optname,
               void *optval, socklen_t *optlen);
int setsockopt(int sockfd, int level, int optname,
               const void *optval, socklen_t optlen);

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Answer 4

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