如何在C++中获得当前的CPU和RAM使用率？

#include<iostream>
#include<string>
#include<vector>
#include <fstream>
#include <sstream>

float getCPUUsage() {
    std::ifstream file("/proc/stat");
    std::string line;
    std::getline(file, line);
    std::istringstream iss(line);
    std::vector<std::string> fields;
    std::string field;
    while (iss >> field) {
        fields.push_back(field);
    }
    long user = std::stol(fields[1]);
    long nice = std::stol(fields[2]);
    long system = std::stol(fields[3]);
    long idle = std::stol(fields[4]);
    long iowait = std::stol(fields[5]);
    long irq = std::stol(fields[6]);
    long softirq = std::stol(fields[7]);
    long total = user + nice + system + idle + iowait + irq + softirq;
    long idle_total = idle + iowait;
    float usage = (float)(total - idle_total) / total;
    return usage;
}

float getRAMUsage() {
    std::ifstream file("/proc/meminfo");
    std::string line;
    long total = 0;
    long free = 0;
    while (std::getline(file, line)) {
        std::istringstream iss(line);
        std::string field;
        iss >> field;
        if (field == "MemTotal:") {
            iss >> total;
        } else if (field == "MemFree:") {
            iss >> free;
        }
    }
    float usage = (float)(total - free) / total;
    return usage;
}

int main() {
    float cpu_usage = getCPUUsage();
    float ram_usage = getRAMUsage();
    std::cout << "CPU usage: "<< cpu_usage * 100 << "%"<< std::endl;
    std::cout << "RAM usage: "<< ram_usage * 100 << "%"<< std::endl;
    return 0;
}