const std::string get_dev_event_kbd()
{
    std::string sline, sdev="/dev/input/", sH="", sBEV="";
    std::ifstream ifs("/proc/bus/input/devices");
    auto trimstr=[](std::string &s)
    {
        int i=0, n=s.length(); //left
        while ((i<n)&&((s[i]==' ')||(s[i]=='t'))) i++;
        s=(i>0)?s.substr(i):s;
        n=s.length()-1; i=n; //right
        while ((i>0)&&((s[i]==' ')||(s[i]=='t')||(s[i]=='n')||(s[i]=='r'))) i--;
        s=(i<n)?s.substr(0,i+1):s;
    };

    while (std::getline(ifs,sline).good())
    {
        if (sline[0]=='H')
        {
            sH=sline.substr(sline.rfind(" event"));
            trimstr(sH);
        }
        if (sline.substr(0,5)=="B: EV")
        {
            sBEV=sline.substr(sline.find('=')+1);
            trimstr(sBEV);
        }
        if (sBEV=="120013") break;
    }
    sdev+=sH;
    return sdev;
}