.TH GETHOSTENT 3N "9 February 1983"
.UC 4
.SH NAME
gethostent, gethostbyaddr, gethostbyname, sethostent, endhostent \- get network host entry
.SH SYNOPSIS
.B "#include <netdb.h>
.PP
.B "struct hostent *gethostent()
.PP
.B "struct hostent *gethostbyname(name)
.br
.B "char *name;
.PP
.B "struct hostent *gethostbyaddr(addr, len, type)
.br
.B "char *addr; int len, type;
.PP
.B "sethostent(stayopen)
.br
.B "int stayopen
.PP
.B "endhostent()
.SH DESCRIPTION
.IR Gethostent ,
.IR gethostbyname ,
and
.I 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,
.IR /etc/hosts .
.RS
.PP
.nf
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 */
};
.ft R
.ad
.fi
.RE
.PP
The members of this structure are:
.TP \w'h_addrtype'u+2n
h_name
Official name of the host.
.TP \w'h_addrtype'u+2n
h_aliases
A zero terminated array of alternate names for the host.
.TP \w'h_addrtype'u+2n
h_addrtype
The type of address being returned; currently always AF_INET.
.TP \w'h_addrtype'u+2n
h_length
The length, in bytes, of the address.
.TP \w'h_addrtype'u+2n
h_addr
A pointer to the network address for the host.
Host addresses are returned
in network byte order.
.PP
.I Gethostent
reads the next line of the file, opening the file if necessary.
.PP
.I Sethostent
opens and rewinds the file.  If the
.I stayopen
flag is non-zero,
the host data base will not be closed after each call to 
.I gethostent
(either directly, or indirectly through one of the other
\*(lqgethost\*(rq calls).
.PP
.I Endhostent
closes the file.
.PP
.I Gethostbyname
and
.I 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.
.SH FILES
/etc/hosts
.SH "SEE ALSO"
hosts(5)
.SH DIAGNOSTICS
Null pointer
(0) returned on EOF or error.
.SH 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.