如何在C中获取CPU和内存使用率？(在Linux系统中)

#include <stdio.h>
#include <stdlib.h>

// 获取CPU使用率
float get_cpu_usage() {
    FILE* file = fopen("/proc/stat", "r");
    if (file == NULL) {
        perror("Failed to open /proc/stat");
        exit(1);
    }

    unsigned long long user, nice, system, idle;
    if (fscanf(file, "cpu %llu %llu %llu %llu", &user, &nice, &system, &idle) != 4) {
        perror("Failed to read CPU usage from /proc/stat");
        exit(1);
    }

    fclose(file);

    unsigned long long total = user + nice + system + idle;
    unsigned long long used = total - idle;
    return (float)used / total * 100.0;
}

// 获取内存使用率
float get_memory_usage() {
    FILE* file = fopen("/proc/meminfo", "r");
    if (file == NULL) {
        perror("Failed to open /proc/meminfo");
        exit(1);
    }

    unsigned long long total, available;
    if (fscanf(file, "MemTotal: %llu kB\nMemAvailable: %llu kB", &total, &available) != 2) {
        perror("Failed to read memory usage from /proc/meminfo");
        exit(1);
    }

    fclose(file);

    unsigned long long used = total - available;
    return (float)used / total * 100.0;
}

int main() {
    float cpu_usage = get_cpu_usage();
    float memory_usage = get_memory_usage();

    printf("CPU Usage: %.2f%%\n", cpu_usage);
    printf("Memory Usage: %.2f%%\n", memory_usage);

    return 0;
}