VMS Help TCPIP Services, Programming Interfaces, Sockets API, setsockopt()  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Sets options on a socket.
    The $QIO equivalent is the IO$_SETMODE function.
    Format
      #include  <types.h>
      #include  <socket.h>
      int setsockopt  ( int s, int level, int optname, char *optval,
                      int optlen );

  Additional Information (explode) :

• Arguments
• Description
• Return Values
• Errors