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

    Allows you to poll or check a group of sockets for I/O activity.
    This function indicates which sockets are ready to be read or
    written, or which sockets have an exception pending.
    Format
      #include  <time.h>
      int select  ( int nfds, int *readfds, int *writefds, int
                  *execptfds, struct timeval *timeout );

  Additional Information (explode) :

• Arguments
• Description
• Return Values
• Errors