Opens a persistent TCP or UDP connection to a remote
host on a specific
port. By default, TCP is used; to connect
host must begin with
udp://. If specified,
timeout indicates the length of time in
seconds to wait before timing out.
If the connection is successful, the function returns a virtual
file pointer that can be used with functions such as
fputs(). If the connection fails, it returns
message are supplied, they are set to the
error number and error string, respectively.
socket opened by this function does not close automatically after
completing a read or write operation on it; you must close it
explicitly with a call to