#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <net/if.h>
#include <errno.h>

int main()
{
    char iface[] = "eth0";
    char ip[] = "192.168.1.3";
    IP_SetIP(iface,ip);
    return 0;
}

int IP_SetIP(const char* interface, const char * ip_address )
{
    int sock=0;
    struct sockaddr_in* addr=NULL;
    struct ifreq ifr;
    
    sock = socket( AF_INET, SOCK_DGRAM, 0 );
    if( sock == -1 ) {
        printf("Can't get a socket!");
        return (-1);
    }
    
    memset(&ifr,0,sizeof( struct ifreq ) );
    strncpy(ifr.ifr_name,interface,IFNAMSIZ);
    
    if( ioctl( sock, SIOCGIFADDR, &ifr ) < 0 ) {
        printf("Can't get IP '%s' because: '%s'\n",interface,strerror(errno));
    }
    else {
        if( ioctl( sock, SIOCDIFADDR, &ifr ) < 0 ) {
            printf("Can't remove '%s' because: '%s'\n",interface,strerror(errno));
        }
    }
    memset( &ifr, 0, sizeof( struct ifreq ) );
    addr= (struct sockaddr_in *)&(ifr.ifr_addr);
    memset(addr, 0, sizeof( struct sockaddr_in) );
    addr->sin_family=AF_INET;
    addr->sin_addr.s_addr=inet_addr(ip_address);
    strncpy(ifr.ifr_name,interface,IFNAMSIZ);
    
    if( ioctl( sock, SIOCSIFADDR, &ifr ) != 0 ) {
        printf("Can't fix IP of '%s' with '%s' because '%s'\n",
        interface,ip_address,strerror(errno));
        close(sock);
        return (-1);
    }
    else {
        printf("IP for '%s' set to'%s'\n",interface,inet_ntoa(addr->sin_addr));
    }
    close(sock);
    return(0);
}