在linux下 获取，修改网关GateWay的两个函数

//获去GateWay

QString GetGateWay(){FILE *fp;char buf[512];char cmd[128];char gateway[30];char *tmp;strcpy(cmd, "ip route");fp = popen(cmd, "r");if(NULL == fp){perror("popen error");return "";}while(fgets(buf, sizeof(buf), fp) != NULL){tmp =buf;while(*tmp && isspace(*tmp))++ tmp;if(strncmp(tmp, "default", strlen("default")) == 0)break;}sscanf(buf, "%*s%*s%s", gateway);printf("default gateway:%s/n", gateway);pclose(fp);return QString(gateway);}

//设置网关

int SetGateWay(const char *szGateWay){int ret = 0;char cmd[128];QString DefGW = GetGateWay();const char *strGW = DefGW.latin1();strcpy(cmd, "route del default gw ");strcat(cmd, strGW);ret = system(cmd);if(ret < 0){perror("route error");return -1;}strcpy(cmd, "route add default gw ");strcat(cmd, szGateWay);ret = system(cmd);if(ret < 0){perror("route error");return -1;}return ret;}