GETHOSTENT(3N-SVR4) RISC/os Reference Manual  GETHOSTENT(3N-SVR4)



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 alter-
                              nate 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-SVR4) RISC/os Reference Manual  GETHOSTENT(3N-SVR4)



          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
     address 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 for-
     mat is currently understood.

















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