/* program to print the IP address of the Host*/
------------------------------------------------
我正在尝试打印主机IP地址。当我执行下面的程序 我得到的回环地址是127.0.0.1
。我应该更改以获取 的实际IP地址。获取环回地址而不是实际地址?
# include <stdio.h>
# include <stdlib.h>
# include <arpa/inet.h>
# include <string.h>
# include <sys/types.h>
# include <sys/socket.h>
# include <netdb.h>
# include <netinet/in.h>
int main() {
void *addr;
char ipstr[INET6_ADDRSTRLEN];
int rv;
struct addrinfo hints, *res, *p;
memset (&hints, 0, sizeof hints);
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
//hints.ai_flags = AI_ADDRCONFIG;
hints.ai_flags = AI_PASSIVE;
if ((rv = getaddrinfo(NULL ,"3490" , &hints, &res)) != 0) {
fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
return 1;
}
for(p = res;p != NULL; p = p->ai_next) {
struct sockaddr_in *ipv4 = (struct sockaddr_in *)p->ai_addr;
addr = &(ipv4->sin_addr);
inet_ntop(p->ai_family, addr, ipstr, sizeof ipstr);
printf(" %s\n", ipstr);
}
}
回送地址*是*实际地址。如果你想得到conencted * hardware *接口的地址,那么你必须求助于平台特定的代码。如果你只是搜索一下,有很多例子。 –
哦,顺便说一下,如果您在列表中获得IPv6地址,该怎么办?那么'p-> ai_addr'不会是'sockaddr_in'指针,因此访问'ipv4-> sin_addr'是未定义的行为。 –
您可以使用'getifaddrs()'获取本地接口的IP地址,请参阅(例如):http://stackoverflow.com/a/12883978/1187415。 –