gethostent(3N)          LIBRARY FUNCTIONS          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 *hname;  /* official name of host */
               char **haliases;   /* alias list */
               int  haddrtype;    /* address type */
               int  hlength; /* length of address */
               char **haddrlist; /* 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  alter-
                              nate names for the host.

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

          h_length            The  length,  in  bytes,   of   the
                              address.

          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



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gethostent(3N)          LIBRARY FUNCTIONS          gethostent(3N)



     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 AFINET this is inaddr
     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 for-
     mat is currently understood.































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