获取linux内核所有ip(C语言)

经常遇到获取接口ip。记录一下，方便后续使用。

在成都网站设计、成都网站建设、外贸网站建设过程中，需要针对客户的行业特点、产品特性、目标受众和市场情况进行定位分析，以确定网站的风格、色彩、版式、交互等方面的设计方向。成都创新互联公司还需要根据客户的需求进行功能模块的开发和设计，包括内容管理、前台展示、用户权限管理、数据统计和安全保护等功能。

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
typedef unsigned int    sf_uint32_t;
typedef unsigned int    in_addr_t;
static inline char* print_ip1(sf_uint32_t ip)
{
    unsigned char* ip_tmp = (unsigned char*) &ip;
    static char buff[20];
    memset(buff ,0 ,sizeof(buff));
    snprintf(buff, sizeof(buff), "%d.%d.%d.%d", ip_tmp[0], ip_tmp[1], ip_tmp[2],
             ip_tmp[3]);
    return buff;
}

in_addr_t
get_myaddr(void)
{
    int             sd, i, lastlen = 0;
    struct ifconf   ifc;
    struct ifreq   *ifrp = NULL;
    in_addr_t       addr;
    char           *buf = NULL;

    if ((sd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
        return 0;
    }

    /*
     * Cope with lots of interfaces and brokenness of ioctl SIOCGIFCONF on
     * some platforms; see W. R. Stevens, ``Unix Network Programming Volume
     * I'', p.435.  
     */

    for (i = 8;; i += 8) {
        buf = (char *) calloc(i, sizeof(struct ifreq));
        if (buf == NULL) {
            close(sd);
            return 0;
        }
        ifc.ifc_len = i * sizeof(struct ifreq);
        ifc.ifc_buf = (caddr_t) buf;

        if (ioctl(sd, SIOCGIFCONF, (char *) &ifc) < 0) {
            if (errno != EINVAL || lastlen != 0) {
                /*
                 * Something has gone genuinely wrong.  
                 */
                free(buf);
                close(sd);
                return 0;
            }
            /*
             * Otherwise, it could just be that the buffer is too small.  
             */
        } else {
            if (ifc.ifc_len == lastlen) {
                /*
                 * The length is the same as the last time; we're done.  
                 */
                break;
            }
            lastlen = ifc.ifc_len;
        }
        free(buf);
    }

    for (ifrp = ifc.ifc_req;
        (char *)ifrp < (char *)ifc.ifc_req + ifc.ifc_len;
#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
        ifrp = (struct ifreq *)(((char *) ifrp) +
                                sizeof(ifrp->ifr_name) +
                                ifrp->ifr_addr.sa_len)
#else
        ifrp++
#endif
        ) {
        if (ifrp->ifr_addr.sa_family != AF_INET) {
            continue;
        }
        addr = ((struct sockaddr_in *) &(ifrp->ifr_addr))->sin_addr.s_addr;

        if (ioctl(sd, SIOCGIFFLAGS, (char *) ifrp) < 0) {
            continue;
        }
        if ((ifrp->ifr_flags & IFF_UP)
#ifdef IFF_RUNNING
            && (ifrp->ifr_flags & IFF_RUNNING)
#endif                          /* IFF_RUNNING */
            /*&& !(ifrp->ifr_flags & IFF_LOOPBACK)
            && addr != LOOPBACK*/) {
            /*
             * I *really* don't understand why this is necessary.  Perhaps for
             * some broken platform?  Leave it for now.  JBPN  
             */
#ifdef SYS_IOCTL_H_HAS_SIOCGIFADDR
            if (ioctl(sd, SIOCGIFADDR, (char *) ifrp) < 0) {
                continue;
            }
            addr =
                ((struct sockaddr_in *) &(ifrp->ifr_addr))->sin_addr.
                s_addr;
#endif
            printf("current ip : %s\n",print_ip1(addr));
        }
    }
    free(buf);
    close(sd);
    return 0;
}

int main()
{
    get_myaddr();
}

本文题目：获取linux内核所有ip
网页路径：http://azwzsj.com/article/ieggji.html