gethostent(3N)                   UNIX System V                   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(void);
      struct hostent *gethostbyaddr(char *addr, int len, int type);
      struct hostent *gethostbyname(char *name);
      int sethostent(int stayopen);
      int endhostent(void);

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).

      The hostent structure has the following members:

            char  *hname;        /* official name of host */
            char  **haliases;    /* alias list */
            int   haddrtype;     /* host 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 alternate 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 not be closed after each call to gethostent
      (either directly, or indirectly through one of the other gethost calls).



10/89                                                                    Page 1

gethostent(3N)                   UNIX System V                   gethostent(3N)


      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 address of type AFINET this is an
      inaddr structure.  See netinet/in.h for the inaddr structure
      definition.

FILES
      /etc/hosts

SEE ALSO
      hosts(4)

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

NOTES
      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.






























Page 2                                                                    10/89