getprotoent(3N)                                      getprotoent(3N)


       NAME
             getprotoent, getprotobynumber, getprotobyname, setprotoent,
             endprotoent - get protocol entry

       SYNOPSIS
             cc [options] file -lsocket -lnsl
             #include <netdb.h>
             struct protoent *getprotoent(void);
             struct protoent *getprotobyname(char *name);
             struct protoent *getprotobynumber(int proto);
             int setprotoent(int stayopen);
             int endprotoent(void);

       DESCRIPTION
             getprotoent, getprotobyname, and getprotobynumber each return
             a pointer to an object with the following structure containing
             the broken-out fields of a line in the network protocol data
             base, /etc/protocols.

             The protoent structure include the following members:

                   char   *p_name;        /* official name of protocol */
                   char   **p_aliases;    /* alias list */
                   int    p_proto;        /* protocol number */

             The members of this structure are:

                   p_name      the official name of the protocol

                   p_aliases   a zero terminated list of alternate names
                               for the protocol

                   p_proto     the protocol number

             getprotoent reads the next line of the file, opening the file
             if necessary.

             setprotoent opens and rewinds the file.  If the stayopen flag
             is non-zero, the net data base will not be closed after each
             call to getprotoent (either directly, or indirectly through
             one of the other getproto calls).

             endprotoent closes the file.





                           Copyright 1994 Novell, Inc.               Page 1

      getprotoent(3N)                                      getprotoent(3N)


            getprotobyname and getprotobynumber sequentially search from
            the beginning of the file until a matching protocol name or
            protocol number is found, or until an EOF is encountered.

         Files
            /etc/protocols
            /var/yp/{domainname}/protocols.byname
            /var/yp/{domainname}/protocols.bynumber

         Return Values
            A NULL pointer is returned on an EOF or error.

      REFERENCES
            protocols(4), ypserv(1M)

      NOTICES
            All information is contained in a static area so it must be
            copied if it is to be saved.  For multi-threaded applications,
            this must be done on a per-thread basis.

            Functions that provide successive entries in files on
            successive calls must be called from a single thread.

            Only the Internet protocols are currently understood.

            The Network Information Service (NIS) will be used to obtain
            protocol entires when its installed and running.  Otherwise,
            entries will be read from /etc/protocols.




















                          Copyright 1994 Novell, Inc.               Page 2