Linux函數實現獲取本機IP和設置IP地址

//獲取本地IP
int GetLocalIp()
{
int sock_get_ip;
char ipaddr[50];

struct sockaddr_in *sin;
struct ifreq ifr_ip;

if((sock_get_ip=socket(AF_INET,SOCK_STREAM,0))==-1)
{
printf("socket create failse /n");
return 0; 
}
memset(&ifr_ip,0,sizeof(ifr_ip));
strncpy(ifr_ip.ifr_name, "eth0", sizeof(ifr_ip.ifr_name) - 1);
    if( ioctl( sock_get_ip, SIOCGIFADDR, &ifr_ip) < 0 )
{
return 0;
}
sin = (struct sockaddr_in *)&ifr_ip.ifr_addr;  
strcpy(ipaddr,inet_ntoa(sin->sin_addr)); 
printf("local ip:%s /n",ipaddr); 
close( sock_get_ip );    
return 1;
}
//設置IP
int SetLocalIp(const char *ipaddr)
{
int sock_set_ip;


struct sockaddr_in sin_set_ip;
struct ifreq ifr_set_ip;


bzero(&ifr_set_ip,sizeof(ifr_set_ip));
if( ipaddr == NULL )   return -1;




if((sock_set_ip=socket(AF_INET,SOCK_STREAM,0))==-1)
{
perror("socket create failse...SetLocalIp!/n");    
return -1;   
}
memset( &sin_set_ip, 0, sizeof(sin_set_ip));  
strncpy(ifr_set_ip.ifr_name, "eth0", sizeof(ifr_set_ip.ifr_name)-1);


sin_set_ip.sin_family = AF_INET;   
sin_set_ip.sin_addr.s_addr = inet_addr(ipaddr);
memcpy( &ifr_set_ip.ifr_addr, &sin_set_ip, sizeof(sin_set_ip));     


if( ioctl( sock_set_ip, SIOCSIFADDR, &ifr_set_ip) < 0 )    
{
perror( "Not setup interface/n");  
return -1;   
}
//設置激活標誌
usleep(100000);
ifr_set_ip.ifr_flags |= IFF_UP |IFF_RUNNING;     
if( ioctl( sock_set_ip, SIOCSIFFLAGS, &ifr_set_ip ) < 0 )   
{
perror("SIOCSIFFLAGS");  
return -1;  
}
usleep(100000);
close( sock_set_ip );  
return 0;
}