IP 를 알고 싶어요...

조기 아래 나와있던 소스입니다. 검색하시면 쉽게 찾을껍니다.

#include <stdio.h> 
#include <stdlib.h> 
#include <string.h> 
#include <ctype.h> 
#include <sys/types.h> 
#include <sys/ioctl.h> 
#include <sys/socket.h> 
#include <netinet/in.h> 
#include <arpa/inet.h> 
#include <stropts.h> 

#if defined(sun) 
#include <sys/sockio.h> 
#endif 

#include <net/if.h> 
#if defined(linux) 
#include <linux/sockios.h> 
#endif 

#define BUFFERSIZE 1024 
const char * localip = "0.0.0.0"; 

const char * myip() 
{ 
	const int MAX_NIC = 10; 
    struct ifconf ifc; 
    struct ifreq ifr[MAX_NIC]; 

    int s; 
    int nNumIFs; 
    int i; 
    int count; 
    int max=2; 
    static char ip[BUFFERSIZE]; 
    int cmd = SIOCGIFCONF; 

    max++; 

    ifc.ifc_len = sizeof ifr; 
    ifc.ifc_ifcu.ifcu_req = ifr; 

    if( (s=socket(AF_INET,SOCK_STREAM,0)) < 0) 
    { 
	    perror("socket"); 
        exit(1); 
    } 

#if defined(_AIX) 
    cmd = CSIOCGIFCONF; 
#endif 

    if( (s = ioctl(s, cmd, &ifc) ) < 0) 
    { 
	    perror("ioctl"); 
        exit(1); 
    } 

    nNumIFs = ifc.ifc_len / sizeof ( struct ifreq ); 
    count = 0; 
    strcpy( ip, localip ); 
    for( i=0; i<nNumIFs; i++ ) 
    { 
  	    struct in_addr addr; 
	    if( ifc.ifc_ifcu.ifcu_req[i].ifr_ifru.ifru_addr.sa_family != AF_INET) 
	    { 
		    continue; 
	    } 

        addr = ((struct sockaddr_in *) & ifc.ifc_ifcu.ifcu_req[i].ifr_ifru.ifru_addr)->sin_addr; 
        if( addr.s_addr == htonl( 0x7f000001 ) ) 
        { 
	        continue; 
        } 
        strcpy( ip, inet_ntoa( addr ) ); 
        printf( "%s IP: %s\n", ifc.ifc_ifcu.ifcu_req[i].ifr_ifrn.ifrn_name, ip ); 
   } 
   return ip; 
} 

int main(void) 
{ 
	printf("One of my IP is %s\n", myip() ); 
    return 0; 
}