/sys$common/syshlp/helplib.hlb CC, Socket Routines, getprotobynumber  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Searches the protocols database until a matching protocol number
    is found or until an EOF is encountered.

    Syntax:

      #include <netdb.h>

      struct protoent *getprotobynumber(int *proto);