GETHOSTENT(NS) UNIX System V
Name
gethostent, gethostbyaddr, gethostbyname, sethostent,
endhostent - Get network host entry
Syntax
#include <netdb.h>
struct hostent *gethostent()
struct hostent *gethostbyname(name)
char *name;
struct hostent *gethostbyaddr
(addr, len, type)
char *addr; int len, type;
sethostent(stayopen)
int stayopen
endhostent()
Description
gethostent, gethostbyname, and gethostbyaddr 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.
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; /* address */
};
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 A pointer to the network address for the 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 EOF is encountered. Host
addresses are supplied in network order.
Files
/etc/hosts
See Also
hosts(NF)
Diagnostics
Null pointer (0) returned on 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.
Use of this routine depends on the local network transport
mechanism
(printed 8/17/89) GETHOSTENT(NS)