fer address */
#define ifc_req ifc_ifcu.ifcu_req /* array of structures */
该结构体可以用来获取所哟网络接口的名字和信息（不是全部信息，是ip地址） （图片来自：http://tech.sunplusedu.com/space/post-4064.
aspx）
Example：
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
typedef uint32_t uint32; #define MAX_IF 10 int main() { struct ifreq ifVec[MAX_IF];//用来保存所有接口 int sock = -1; if ( (sock = socket( AF_INET, SOCK_DGRAM, 0 )) < 0 ) fprintf(stderr, "Error:%d, cannot open RAM;\n"); // get if vector struct ifconf ioIfConf; ioIfConf.ifc_buf = (void *)ifVec; ioIfConf.ifc_len = sizeof(ifVec); printf("Len:%d\n", ioIfConf.ifc_len); if (ioctl(sock, SIOCGIFCONF, &ioIfConf) < 0 )//获取所有网络接口信息 fprintf(stderr, "Error:%d ioctl IFCONF\n"); printf("Len:%d\n", ioIfConf.ifc_len);// 和前面到len对比，发现ioctl修改里len到大小 //循环打印每个网络接口到信息 { struct ifreq *ifPt; struct ifreq *ifEndPt; ifPt = ifVec; ifEndPt = (void *)((char *)ifVec + ioIfConf.ifc_len); for (ifPt = ifVec; ifPt < ifEndPt; ifPt++) { struct ifreq ifReq; if ( ifPt->ifr_addr.sa_family != AF_INET ) { continue; } // Temp keepers of interface params... uint32 u32_addr, u32_mask; /* 打印ip地址 */ char ipDotBuf[16], subnetDotBuf[16], maskDotBuf[16]; // 保存点分十进制到ip地址 u32_addr = ((struct sockaddr_in *)&ifPt->ifr_addr)->sin_addr.s_addr; inet_ntop(AF_INET, &u32_addr, ipDotBuf, (socklen_t )sizeof(ipDotBuf)); printf("IP Address: %s\n", ipDotBuf); /* 打印地址掩码 */ bzero(&ifReq,sizeof(struct ifreq)); memcpy(ifReq.ifr_name, ifPt->ifr_name, sizeof(ifReq.ifr_name)); if (ioctl(sock, SIOCGIFNETMASK, &ifReq ) < 0){ fprintf(stderr, "Error: %d, cannot get mask\n", errno); } else{ u32_mask = ((struct sockaddr_in *)&ifReq.ifr_addr)->sin_addr.s_addr; inet_ntop(AF_INET, &u32_mask, maskDotBuf, (socklen_t )sizeof(maskDotBuf)); printf("Mask: %s\n", maskDotBuf); } /* 打印MTU */ bzero(&ifReq,sizeof(struct ifreq)); memcpy(ifReq.ifr_name, ifPt->ifr_name, sizeof(ifReq.ifr_name)); if (ioctl(sock, SIOCGIFMTU, &ifReq ) < 0){ fprintf(stderr, "Error: %d, cannot get MTU\n", errno); } else{ printf("SIOCGIFMTU:%d\n", ifReq.ifr_mtu); } /* 其他信息的打印方式与掩码和MTU相同 */ } } }
运行结果：
windeal@ubuntu:~/Windeal/apue$ ./exe
Len:320
Len:64
IP Address: 127.0.0.1
Mask: 255.0.0.0
SIOCGIFMTU:16436
IP Address: 172.17.92.198
Mask: 255.255.254.0
SIOCGIFMTU:1500
windeal@ubuntu:~/Windeal/apue$