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. "192.0.34.72"); 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.
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; 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);