用C/C++实现linux下检测网络接口状态

#include <sys/types.h>#include <string.h>#include <stdlib.h>#include <sys/ioctl.h>#include <stdio.h>#include <errno.h>#include <net/if.h> struct ethtool_value { __uint32_t cmd; __uint32_t data;}; /*return 1:has cable; return 0:no cable*/int detect_eth_cable(char *ifname) { struct ethtool_value edata; struct ifreq ifr; int fd = -1, err = 0;  memset(&ifr, 0, sizeof(ifr)); strcpy(ifr.ifr_name, ifname);  fd = socket(AF_INET, SOCK_DGRAM, 0); if (fd < 0) {  //perror("Cannot get control socket");  return -1;  } edata.cmd = 0x0000000A; ifr.ifr_data = (caddr_t)&edata; err = ioctl(fd, 0x8946, &ifr); if (err == 0) {  fprintf(stdout, "Link detected: %s/n", edata.data ? "yes":"no"); } else if (errno != EOPNOTSUPP) {  perror("Cannot get link status");  } return(edata.data==1 ? 1:0);}int main(int argc, char**argv){ detect_eth_cable("p1p1"); return 0;}

int get_netportstatus(const char *interface) { char cmd[1024]; char *tt; FILE *fp; int devflag; devflag=get_netflag(interface); if (devflag==DEV_DOWN) { sprintf(cmd,"ifconfig %s up",interface); system(cmd); } sprintf(cmd,"ethtool %s | grep /"Link detected/" > /tmp/eth.temp",interface); system(cmd); if (devflag==DEV_DOWN) { sprintf(cmd,"ifconfig %s down",interface); system(cmd); } fp=fopen("/tmp/eth.temp","r"); if (fp==NULL) { system("rm -rf /tmp/eth.temp"); return -1; } fgets(cmd,1024,fp); fclose(fp); system("rm -rf /tmp/eth.temp"); tt=strstr(cmd,"no"); if (tt!=NULL) return LINK_DOWN; tt=strstr(cmd,"yes"); if (tt!=NULL) return LINK_UP; return -1;}

#include <sys/types.h>#include <string.h>#include <stdlib.h>#include <sys/ioctl.h>#include <stdio.h>#include <errno.h>#include <net/if.h>  struct ethtool_value {  __uint32_t  cmd;  __uint32_t  data;};  int main(int , char* []){ struct ethtool_value edata; int fd = -1, err = 0; struct ifreq ifr;    memset(&ifr, 0, sizeof(ifr));  strcpy(ifr.ifr_name, "eth0");  fd = socket(AF_INET, SOCK_DGRAM, 0);  if (fd < 0) {    perror("Cannot get control socket");    return 70;  }  edata.cmd = 0x0000000a;  ifr.ifr_data = (caddr_t)&edata;  err = ioctl(fd, 0x8946, &ifr);  if (err == 0) {    fprintf(stdout, "Link detected: %s/n",      edata.data ? "yes":"no");  } else if (errno != EOPNOTSUPP) {    perror("Cannot get link status");  } return 0;}

#include <net if.h=""> // IFF_RUNNING //如果网卡已脸上网线，返回0，否则返回-1.int check_nic(char *nic){ struct ifreq ifr; int skfd = socket(AF_INET, SOCK_DGRAM, 0);  strcpy(ifr.ifr_name, nic_name); if (ioctl(skfd, SIOCGIFFLAGS, &ifr) < 0) {  return -1; } if(ifr.ifr_flags & IFF_RUNNING)  return 0; // 网卡已插上网线 else return -1;}</net>