gethostbyname是否支持IPv6地址解析

gethostbyname 函数本身不直接支持 IPv6 地址解析

要在代码中使用 getaddrinfo，请参考以下示例：

#include<stdio.h>#include <stdlib.h>#include<string.h>#include <netdb.h>#include <arpa/inet.h>#include <sys/types.h>#include <sys/socket.h>int main(int argc, char *argv[]) {    struct addrinfo hints, *res, *p;    int status;    char ipstr[INET6_ADDRSTRLEN];    if (argc != 2) {        fprintf(stderr, "Usage: %s hostname\n", argv[0]);        exit(1);    }    mEMSet(&hints, 0, sizeof hints);    hints.ai_family = AF_UNSPEC; // AF_INET or AF_INET6 to force version    hints.ai_socktype = SOCK_STREAM;    if ((status = getaddrinfo(argv[1], NULL, &hints, &res)) != 0) {        fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(status));        exit(1);    }    printf("IP addresses for %s:\n\n", argv[1]);    for (p = res; p != NULL; p = p->ai_next) {        void *addr;        char *ipver;        // get the pointer to the address itself,        // different fields in IPv4 and IPv6:        if (p->ai_family == AF_INET) { // IPv4            struct sockaddr_in *ipv4 = (struct sockaddr_in *)p->ai_addr;            addr = &(ipv4->sin_addr);            ipver = "IPv4";        } else { // IPv6            struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)p->ai_addr;            addr = &(ipv6->sin6_addr);            ipver = "IPv6";        }        // convert the IP to a string and print it:        inet_ntop(p->ai_family, addr, ipstr, sizeof ipstr);        printf("%s: %s\n", ipver, ipstr);    }    freeaddrinfo(res); // remember to free the memory allocated by getaddrinfo    return 0;}

这个示例程序将输入的主机名解析为 IPv4 和 IPv6 地址。如果你只想解析特定版本的地址，可以通过修改 hints.ai_family 来实现。