getprotoent(3N)                                             getprotoent(3N)


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

   SYNOPSIS
         #include <netdb.h>

         struct protoent *getprotoent()

         struct protoent *getprotobyname(name)
         char *name;

         struct protoent *getprotobynumber(proto)
         int proto;

         setprotoent(stayopen)
         int stayopen;

         endprotoent()

   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.

               struct      protoent {
                     char  *pname;    /* official name of protocol */
                     char  **paliases;      /* alias list */
                     int   pproto;    /* 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).





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   getprotoent(3N)                                             getprotoent(3N)


         endprotoent() closes the file.

         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

   SEE ALSO
         protocols(4)

   DIAGNOSTICS
         A NULL pointer is returned on an EOF or error.

   BUGS
         All information is contained in a static area so it must be copied if
         it is to be saved.  Only the Internet protocols are currently
         understood.


































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