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.

     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.