从接口名称查找IP地址 [英] Finding an IP address from an interface name
问题描述
在Linux机器上,通用接口名称看起来像eth0,eth1等.我知道如何使用gethostbyname
或类似函数查找至少一个IP地址,但是我不知道指定哪种命名方式.接口我要的IP地址.我可以使用ifconfig并解析输出,但是为这些信息掏腰包似乎……不雅.
On a Linux box, the common interface names look like eth0, eth1, etc. I know how to find at least one IP address using gethostbyname
or similar functions, but I don't know any way to specify which named interface I want the IP address of. I could use ifconfig and parse the output, but shelling out for this information seems... inelegant.
是否有办法将所有接口及其IP地址(可能还有MAC地址)枚举到一个集合中?或者至少是gethostbyinterface("eth0")
的东西?
Is there a way to, say, enumerate all the interfaces and their IP addresses (and maybe MAC addresses) into a collection? Or at least something along the lines of gethostbyinterface("eth0")
?
推荐答案
// Originally from http://www.tlug.org.za/wiki/index.php/Obtaining_your_own_IP_address
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
/**
* getIPv4()
*
* This function takes a network identifier such as "eth0" or "eth0:0" and
* a pointer to a buffer of at least 16 bytes and then stores the IP of that
* device gets stored in that buffer.
*
* it return 0 on success or -1 on failure.
*
* Author: Jaco Kroon <jaco@kroon.co.za>
*/
int getIPv4(const char * dev, char * ipv4) {
struct ifreq ifc;
int res;
int sockfd = socket(AF_INET, SOCK_DGRAM, 0);
if(sockfd < 0)
return -1;
strcpy(ifc.ifr_name, dev);
res = ioctl(sockfd, SIOCGIFADDR, &ifc);
close(sockfd);
if(res < 0)
return -1;
strcpy(ipv4, inet_ntoa(((struct sockaddr_in*)&ifc.ifr_addr)->sin_addr));
return 0;
}
int main() {
char ip[16];
if(getIPv4("eth0", ip) == 0)
printf("IPv4: %s\n", ip);
else
printf("No IP\n");
return 0;
}
更新:将无效链接移至注释(供后代使用)(感谢@obayhan),并添加了语法高亮显示.
Update: Moved dead link to a comment (for posterity) (thanks @obayhan), and added syntax highlighting.
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