getSysRamPercent() And More!

getSysRamPercent

Logic is the same as in the previous examples. We are opening a stream on proc/memInfo where we can read three characteristic values: MemAvailable,buffers and memFree. From these values we are calculating RAM usage in percentage.

float ProcessParser::getSysRamPercent()
{
    string line;
    string name1 = "MemAvailable:";
    string name2 = "MemFree:";
    string name3 = "Buffers:";

    string value;
    int result;
    ifstream stream = Util::getStream((Path::basePath() + Path::memInfoPath()));
    float total_mem = 0;
    float free_mem = 0;
    float buffers = 0;
    while (std::getline(stream, line)) {
        if (total_mem != 0 && free_mem != 0)
            break;
        if (line.compare(0, name1.size(), name1) == 0) {
            istringstream buf(line);
            istream_iterator<string> beg(buf), end;
            vector<string> values(beg, end);
            total_mem = stof(values[1]);
        }
        if (line.compare(0, name2.size(), name2) == 0) {
            istringstream buf(line);
            istream_iterator<string> beg(buf), end;
            vector<string> values(beg, end);
            free_mem = stof(values[1]);
        }
        if (line.compare(0, name3.size(), name3) == 0) {
            istringstream buf(line);
            istream_iterator<string> beg(buf), end;
            vector<string> values(beg, end);
            buffers = stof(values[1]);
        }
    }
    //calculating usage:
    return float(100.0*(1-(free_mem/(total_mem-buffers))));
}

getSysKernelVersion()

Open a stream on /proc/version. Getting data about the kernel version.

string ProcessParser::getSysKernelVersion()
{
    string line;
    string name = "Linux version ";
    ifstream stream = Util::getStream((Path::basePath() + Path::versionPath()));
    while (std::getline(stream, line)) {
        if (line.compare(0, name.size(),name) == 0) {
            istringstream buf(line);
            istream_iterator<string> beg(buf), end;
            vector<string> values(beg, end);
            return values[2];
        }
    }
    return "";
}

getOsName()

Read /etc/os-release. We expect a string with extra characters, which we delete based on specifications in documentation. The result is the name of the operating system.

string ProcessParser::getOsName()
{
    string line;
    string name = "PRETTY_NAME=";

    ifstream stream = Util::getStream(("/etc/os-release"));

    while (std::getline(stream, line)) {
        if (line.compare(0, name.size(), name) == 0) {
              std::size_t found = line.find("=");
              found++;
              string result = line.substr(found);
              result.erase(std::remove(result.begin(), result.end(), '"'), result.end());
              return result;
        }
    }
    return "";

}

getTotalThreads()

The total thread count is calculated, rather than read from a specific file.

We open every PID folder and read its thread count. After that, we sum the thread counts to calculate the total number of threads on the host machine.

int ProcessParser::getTotalThreads()
{
    string line;
    int result = 0;
    string name = "Threads:";
    vector<string>_list = ProcessParser::getPidList();
    for (int i=0 ; i<_list.size();i++) {
    string pid = _list[i];
    //getting every process and reading their number of their threads
    ifstream stream = Util::getStream((Path::basePath() + pid + Path::statusPath()));
    while (std::getline(stream, line)) {
        if (line.compare(0, name.size(), name) == 0) {
            istringstream buf(line);
            istream_iterator<string> beg(buf), end;
            vector<string> values(beg, end);
            result += stoi(values[1]);
            break;
        }
    }
    return result;
}

getTotalNumberOfProcesses()

Retrieve this info by reading /proc/stat. Search for the “processes” line.

int ProcessParser::getTotalNumberOfProcesses()
{
    string line;
    int result = 0;
    string name = "processes";
    ifstream stream = Util::getStream((Path::basePath() + Path::statPath()));
    while (std::getline(stream, line)) {
        if (line.compare(0, name.size(), name) == 0) {
            istringstream buf(line);
            istream_iterator<string> beg(buf), end;
            vector<string> values(beg, end);
            result += stoi(values[1]);
            break;
        }
    }
    return result;
}

getNumberOfRunningProcesses()

This function uses the same logic as previous functions.

int ProcessParser::getNumberOfRunningProcesses()
{
    string line;
    int result = 0;
    string name = "procs_running";
    ifstream stream = Util::getStream((Path::basePath() + Path::statPath()));
    while (std::getline(stream, line)) {
        if (line.compare(0, name.size(), name) == 0) {
            istringstream buf(line);
            istream_iterator<string> beg(buf), end;
            vector<string> values(beg, end);
            result += stoi(values[1]);
            break;
        }
    }
    return result;
}