"Fossies" - the Fresh Open Source Software Archive

Member "neon-0.31.2/doc/html/refresolve.html" (20 Jun 2020, 7483 Bytes) of package /linux/www/neon-0.31.2.tar.gz:

Caution: In this restricted "Fossies" environment the current HTML page may not be correctly presentated and may have some non-functional links. You can here alternatively try to browse the pure source code or just view or download the uninterpreted raw source code. If the rendering is insufficient you may try to find and view the page on the project site itself.


ne_addr_resolve, ne_addr_result, ne_addr_first, ne_addr_next, ne_addr_error, ne_addr_destroy — functions to resolve hostnames to addresses


#include <ne_socket.h>
ne_sock_addr *ne_addr_resolve(const char *hostname,
 int flags);
int ne_addr_result(const ne_sock_addr *addr);
const ne_inet_addr *ne_addr_first(ne_sock_addr *addr);
const ne_inet_addr *ne_addr_next(ne_sock_addr *addr);
char *ne_addr_error(const ne_sock_addr *addr,
 char *buffer,
 size_t bufsiz);
void ne_addr_destroy(ne_sock_addr *addr);


The ne_addr_resolve function resolves the given hostname, returning an ne_sock_addr object representing the address (or addresses) associated with the hostname. The flags parameter is currently unused, and must be passed as 0.

The hostname passed to ne_addr_resolve can be a DNS hostname (e.g. "www.example.com") or an IPv4 dotted quad (e.g. ""); or, on systems which support IPv6, an IPv6 hex address, which may be enclosed in brackets, e.g. "[::1]".

To determine whether the hostname was successfully resolved, the ne_addr_result function is used, which returns non-zero if an error occurred. If an error did occur, the ne_addr_error function can be used, which will copy the error string into a given buffer (of size bufsiz).

The functions ne_addr_first and ne_addr_next are used to retrieve the Internet addresses associated with an address object which has been successfully resolved. ne_addr_first returns the first address; ne_addr_next returns the next address after the most recent call to ne_addr_next or ne_addr_first, or NULL if there are no more addresses. The ne_inet_addr pointer returned by these functions can be passed to ne_sock_connect to connect a socket.

After the address object has been used, it should be destroyed using ne_addr_destroy.

Return value

ne_addr_resolve returns a pointer to an address object, and never NULL. ne_addr_error returns the buffer parameter .


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

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;
    for (ia = ne_addr_first(addr); ia != NULL; ia = ne_addr_next(addr)) {
        printf(" %s", ne_iaddr_print(ia, buf, sizeof buf));

See also