ne_addr_resolve.3

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.TH "NE_ADDR_RESOLVE" 3 "5 July 2004" "neon 0.24.7" "neon API reference"
.SH NAME
ne_addr_resolve, ne_addr_result, ne_addr_first, ne_addr_next, ne_addr_error, ne_addr_destroy \- functions to resolve hostnames to addresses
.SH "SYNOPSIS"
.ad l
.hy 0

#include <ne_socket\&.h>
.sp
.HP 31
ne_sock_addr\ *\fBne_addr_resolve\fR\ (const\ char\ *\fIhostname\fR, int\ \fIflags\fR);
.HP 20
int\ \fBne_addr_result\fR\ (const\ ne_sock_addr\ *\fIaddr\fR);
.HP 36
const\ ne_inet_addr\ *\fBne_addr_first\fR\ (ne_sock_addr\ *\fIaddr\fR);
.HP 35
const\ ne_inet_addr\ *\fBne_addr_next\fR\ (ne_sock_addr\ *\fIaddr\fR);
.HP 21
char\ *\fBne_addr_error\fR\ (const\ ne_sock_addr\ *\fIaddr\fR, char\ *\fIbuffer\fR, size_t\ \fIbufsiz\fR);
.HP 22
void\ \fBne_addr_destroy\fR\ (ne_sock_addr\ *\fIaddr\fR);
.ad
.hy

.SH "DESCRIPTION"

.PP
The \fBne_addr_resolve\fR function resolves the given \fIhostname\fR, returning an \fBne_sock_addr\fR object representing the address (or addresses) associated with the hostname\&. The \fIflags\fR parameter is currently unused, and must be passed as 0\&.

.PP
The \fIhostname\fR passed to \fBne_addr_resolve\fR can be a DNS hostname (e\&.g\&. "www\&.example\&.com") or an IPv4 dotted quad (e\&.g\&. "192\&.0\&.34\&.72"); or, on systems which support IPv6, an IPv6 hex address, which may be enclosed in brackets, e\&.g\&. "[::1]"\&.

.PP
To determine whether the hostname was successfully resolved, the \fBne_addr_result\fR function is used, which returns non\-zero if an error occurred\&. If an error did occur, the \fBne_addr_error\fR function can be used, which will copy the error string into a given \fIbuffer\fR (of size \fIbufsiz\fR)\&.

.PP
The functions \fBne_addr_first\fR and \fBne_addr_next\fR are used to retrieve the Internet addresses associated with an address object which has been successfully resolved\&. \fBne_addr_first\fR returns the first address; \fBne_addr_next\fR returns the next address after the most recent call to \fBne_addr_next\fR or \fBne_addr_first\fR, or NULL if there are no more addresses\&. The \fBne_inet_addr\fR pointer returned by these functions can be passed to \fBne_sock_connect\fR to connect a socket\&.

.PP
After the address object has been used, it should be destroyed using \fBne_addr_destroy\fR\&.

.SH "RETURN VALUE"

.PP
\fBne_addr_resolve\fR returns a pointer to an address object, and never NULL\&. \fBne_addr_error\fR returns the \fIbuffer\fR parameter \&.

.SH "EXAMPLES"

.PP
The code below prints out the set of addresses associated with the hostname www\&.google\&.com\&.

.nf
ne_sock_addr *addr;
char buf[256];

addr = ne_addr_resolve("www\&.google\&.com", 0);
if (ne_addr_result(addr)) {
    printf("Could not resolve www\&.google\&.com: %s\\n",
           ne_addr_error(addr, buf, sizeof buf));
} else {
    const ne_inet_addr *ia;
    printf("www\&.google\&.com:");
    for (ia = ne_addr_first(addr); ia != NULL; ia = ne_addr_next(addr)) {
        printf(" %s", ne_iaddr_print(ia, buf, sizeof buf));
    }
    putchar('\\n');
}
ne_addr_destroy(addr);

.fi

.SH "SEE ALSO"

.PP
\fBne_iaddr_print\fR(3)

.SH AUTHOR
Joe Orton <neon@webdav\&.org>.