gethostent(3N)                                               gethostent(3N)


   NAME
         gethostent, gethostbyaddr, gethostbyname, sethostent, endhostent -
         get network host entry

   SYNOPSIS
         #include <sys/types.h>
         #include <sys/socket.h>
         #include <netdb.h>

         struct hostent *gethostent()

         struct hostent *gethostbyaddr(addr, len, type)
         char *addr;
         int len, type;

         struct hostent *gethostbyname(name)
         char *name;

         sethostent(stayopen)
         int stayopen

         endhostent()

   DESCRIPTION
         gethostent(), gethostbyaddr(), and gethostbyname() each return a
         pointer to an object with the following structure containing the
         broken-out fields of a line in the network host data base,
         /etc/hosts.  In the case of gethostbyaddr(), addr is a pointer to the
         binary format address of length len (not a character string).

               struct      hostent {
                     char  *h_name;    /* official name of host */
                     char  **h_aliases;      /* alias list */
                     int   h_addrtype; /* address type */
                     int   h_length;   /* length of address */
                     char  **h_addr_list;    /* list of addresses from name server */
               };

         The members of this structure are:

               h_name              Official name of the host.

               h_aliases           A zero terminated array of alternate names
                                   for the host.

               h_addrtype          The type of address being returned;
                                   currently always AF_INET.

               h_length            The length, in bytes, of the address.




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   gethostent(3N)                                               gethostent(3N)


               h_addr_list         A pointer to a list of network addresses
                                   for the named host.  Host addresses are
                                   returned in network byte order.

         gethostent() reads the next line of the file, opening the file if
         necessary.

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

         endhostent() closes the file.

         gethostbyname() and gethostbyaddr() sequentially search from the
         beginning of the file until a matching host name or host address is
         found, or until an EOF is encountered.  Host addresses are supplied
         in network order.

         gethostbyaddr() takes a pointer to an address structure.  This
         structure is unique to each type of address.  For addres of type
         AF_INET this is in_addr structure.  See <netinet/in.h>.

   FILES
         /etc/hosts

   SEE ALSO
         hosts(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 address format is currently
         understood.

















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