Re: tool for converting IPv6 address strings

[Jun-ichiro itojun Hagino]

        this should be okay.

itojun

#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <netdb.h>

int
main(argc, argv)
        int argc;
        char **argv;
{
        char hbuf[NI_MAXHOST];
        struct addrinfo hints, *res;
        int error;
#ifdef NI_WITHSCOPEID   /*KAME*/
        const int niflags = NI_NUMERICHOST | NI_WITHSCOPEID;
#else
        const int niflags = NI_NUMERICHOST;
#endif

        if (argc != 2) {
                fprintf(stderr, "usage: foo addr\n");
                exit(1);
        }

        memset(&hints, 0, sizeof(hints));
        hints.ai_family = PF_INET6;
        hints.ai_socktype = SOCK_DGRAM; /*dummy*/
        hints.ai_flags = AI_NUMERICHOST;
        error = getaddrinfo(argv[1], "0", &hints, &res);
        if (error) {
                fprintf(stderr, "foo: getaddrinfo: %s\n", gai_strerror(error));
                exit(1);
        }
        error = getnameinfo(res->ai_addr, res->ai_addrlen, hbuf, sizeof(hbuf),
            NULL, 0, niflags);
        if (error) {
                fprintf(stderr, "foo: getnameinfo: %s\n", gai_strerror(error));
                exit(1);
        }
        printf("%s\n", hbuf);
        exit(0);
}