getip.c

来自「在linux下c语言获取本机ip地址的函数,解除了只能获取127.0.0.1的b」· C语言 代码 · 共 51 行

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <signal.h>

#include <sys/ioctl.h>
#include <linux/if.h>
long getlocalhostip(){
  int  MAXINTERFACES=16;
	long ip;
	int fd, intrface, retn = 0;
 	struct ifreq buf[MAXINTERFACES]; ///if.h
	struct ifconf ifc; ///if.h
	ip = -1;
	if ((fd = socket (AF_INET, SOCK_DGRAM, 0)) >= 0) //socket.h
	{
 		ifc.ifc_len = sizeof buf;
 		ifc.ifc_buf = (caddr_t) buf;
 		if (!ioctl (fd, SIOCGIFCONF, (char *) &ifc)) //ioctl.h
		{
 			intrface = ifc.ifc_len / sizeof (struct ifreq); 
			while (intrface-- > 0)
 			{
 				if (!(ioctl (fd, SIOCGIFADDR, (char *) &buf[intrface])))
 				{
 					ip=inet_addr( inet_ntoa( ((struct sockaddr_in*)(&buf[intrface].ifr_addr))->sin_addr) );//types
 					break;
				}
           			
			}
			
		}
 		close (fd);
 	}
	return ip;
}
union ipu{
	long ip;
	unsigned char ipchar[4];
	};
int main(int argc, char **argv){
	union ipu iptest;
	iptest.ip = getlocalhostip();	
	printf("local ip:%x :%3u.%3u.%3u.%3u \n",iptest.ip, iptest.ipchar[0],iptest.ipchar[1],iptest.ipchar[2],iptest.ipchar[3]);
	return 0;
}