判断IP端口是否占用

bool srvPortIsUsed(int devPort)
{
string str_dev = std::to_string(devPort)+".txt";
std::strstream srm;
//srm << "lsof -i :" << devPort << " >netstat.txt";
srm << "lsof -i :" << devPort << " >" << str_dev;
system(srm.str());
//std::ifstream in("netstat.txt");
std::ifstream in(str_dev);
std::string line;
std::getline(in, line);
std::getline(in, line);
if (!line.empty() && (line != "")) {
line.find_first_of(' ');
line = line.substr(line.find_first_of(' ') + 1);
line = line.substr(0, line.find_first_of(' '));
std::string sr = "kill -9 " + line;
system(sr.c_str());
return true;
}
else{
return false;
}
}