Here are the functions for examining and modifying socket options. They are declared in sys/socket.h.
Preliminary: | MT-Safe | AS-Safe | AC-Safe | See POSIX Safety Concepts.
The
getsockopt
function gets information about the value of option optname at level level for socket socket.The option value is stored in a buffer that optval points to. Before the call, you should supply in
*
optlen-ptr the size of this buffer; on return, it contains the number of bytes of information actually stored in the buffer.Most options interpret the optval buffer as a single
int
value.The actual return value of
getsockopt
is0
on success and-1
on failure. The followingerrno
error conditions are defined:
EBADF
- The socket argument is not a valid file descriptor.
ENOTSOCK
- The descriptor socket is not a socket.
ENOPROTOOPT
- The optname doesn't make sense for the given level.
Preliminary: | MT-Safe | AS-Safe | AC-Safe | See POSIX Safety Concepts.
This function is used to set the socket option optname at level level for socket socket. The value of the option is passed in the buffer optval of size optlen.