linux C 获取与修改IP地址

// setip.h
#ifndef _INCLUDE_SETIP_H_
#define _INCLUDE_SETIP_H_

// 设置IP地址

int setip(char *ip);

// 获取IP地址

char* getip(char *ip_buf);

#endif

// end setip.h

//setip.c

#include<stdio.h>

#include<stdlib.h>

#include<string.h>

#include<sys/ioctl.h>

#include<sys/socket.h>

#include<arpa/inet.h>

#include<netinet/in.h>

#include<net/if.h>

#include "setip.h"

//设置IP地址

int setip(char* ip)

{

    struct ifreq temp;

    struct sockaddr_in *addr;

    int fd = 0;

    int ret = -1;

    strcpy(temp.ifr_name, "eth0");

    if((fd=socket(AF_INET, SOCK_STREAM, 0))<0)

    {

        return -1;

    }

    addr = (struct sockaddr_in *)&(temp.ifr_addr);

    addr->sin_family = AF_INET;

    addr->sin_addr.s_addr = inet_addr(ip);

    ret = ioctl(fd, SIOCSIFADDR, &temp);

    close(fd);

    if(ret < 0)

        return -1;

    return 0;

}

// 获取IP地址

char* getip(char* ip_buf)

{

    struct ifreq temp;

    struct sockaddr_in *myaddr;

    int fd = 0;

    int ret = -1;

    strcpy(temp.ifr_name, "eth0");

    if((fd=socket(AF_INET, SOCK_STREAM, 0))<0)

    {

        return NULL;

    }

    ret = ioctl(fd, SIOCGIFADDR, &temp);

    close(fd);

    if(ret < 0)

        return NULL;

    myaddr = (struct sockaddr_in *)&(temp.ifr_addr);

    strcpy(ip_buf, inet_ntoa(myaddr->sin_addr));

    return ip_buf;

}

int main(int argc, char * argv[])

{

    char * ip = "172.20.223.117";

    char buf[16]="";

    setip(argv[1]);

    printf("ipaddr=%s/n",getip(buf));

    return 0;

}

// end setip.c