基于C++20构建测试 (g++ 10.2.1)
CMakeLists.txt
# 设置用于构建该项目的最低cmake版本
cmake_minimum_required(VERSION 3.1)
# 设置项目名称和编程语言
project(获取Linux信息 CXX)
# 设置二进制文件生成路径
set(EXECUTABLE_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/bin)
# 获取源码的路径
aux_source_directory(src src)
# 设置编译标准和额外参数
add_compile_options(-std=c++20 -Wall -Werror -Wextra -pedantic -Wimplicit-fallthrough -Wsequence-point -Wswitch-default -Wswitch-unreachable -Wswitch-enum -Wstringop-truncation -Wbool-compare -Wtautological-compare -Wfloat-equal -Wshadow=global -Wpointer-arith -Wpointer-compare -Wcast-align -Wcast-qual -Wwrite-strings -Wdangling-else -Wlogical-op -Wconversion -Wno-pedantic-ms-format)
# 从源码构建二进制文件
add_executable(demo ${src})
结构参考下图
/**
* @file getIP.cpp
* @author IYATT-yx
* @brief 获取IP
* @details Ubuntu 20.04 64-bit C++20
*/
#include <iostream>
#include <cstring>
extern "C"
{
#include <arpa/inet.h>
#include <ifaddrs.h>
#include <netinet/in.h>
}
int main()
{
struct ifaddrs *ifAddrStruct = NULL;
void *tmpAddrPtr = NULL;
getifaddrs(&ifAddrStruct);
while (ifAddrStruct != NULL)
{
if (ifAddrStruct->ifa_addr->sa_family == AF_INET)
{
tmpAddrPtr = &((struct sockaddr_in *)ifAddrStruct->ifa_addr)->sin_addr;
char addressBuffer[INET_ADDRSTRLEN];
inet_ntop(AF_INET, tmpAddrPtr, addressBuffer, INET_ADDRSTRLEN);
if (strcmp(ifAddrStruct->ifa_name, "eth0") == 0)
{
std::cout << "eth0: " << addressBuffer << std::endl;
break;
}
else if (strcmp(ifAddrStruct->ifa_name, "wlan0") == 0)
{
std::cout << "wlan0: " << addressBuffer << std::endl;
break;
}
}
ifAddrStruct = ifAddrStruct->ifa_next;
}
}
磁盘信息
/**
* @file getDiskInfo.cpp
* @author IYATT-yx
* @brief 获取磁盘使用信息
* @details Ubuntu 20.04 64-bit C++20
*/
#include <iostream>
extern "C"
{
#include <sys/vfs.h>
#include <unistd.h>
}
struct statfs diskInfo;
int main()
{
statfs("/", &diskInfo);
long long unsigned totalBlocks = diskInfo.f_bsize;
long long unsigned totalSize = (totalBlocks * diskInfo.f_blocks) >> 20;
long long unsigned freeDisk = (diskInfo.f_bfree * totalBlocks) >> 20;
std::cout << "磁盘总大小: " << totalSize << " MB"
<< "\n空闲大小: " << freeDisk << " MB" << std::endl;
}
计算原理 (仅供参考):
将每两次读取 /proc/stat 中的数据计算差值 (源数据是从计算机启动开始计时到读取时的时间), 然后实现计算 (user + nice + system + iowait + irq + softifq) / (user + nice + system + idle + iowait + irq + softirq) 作为CPU使用率
| 第一行的数据 | 解释 |
|---|---|
| user | 从系统启动开始累计到当前时刻，处于用户态的运行时间，不包含 nice值为负进程 |
| nice | 从系统启动开始累计到当前时刻，nice值为负的进程所占用的CPU时间 |
| system | 从系统启动开始累计到当前时刻，处于核心态的运行时间 |
| idle | 从系统启动开始累计到当前时刻，除IO等待时间以外的其它等待时间 |
| iowait | 从系统启动开始累计到当前时刻，IO等待时间 |
| irq | 从系统启动开始累计到当前时刻，硬中断时间 |
| softirq | 从系统启动开始累计到当前时刻，软中断时间 |
/**
* @file getCpuUsage.cpp
* @author IYATT-yx
* @brief 计算CPU使用率
* @details Ubuntu 20.04 64-bit C++20
*/
#include <iostream>
#include <fstream>
extern "C"
{
#include <unistd.h>
}
int main()
{
std::string cpu;
std::ifstream readCPU;
readCPU.open("/proc/stat", std::ifstream::in);
long luser, lnice, lsys, lidle, liowait, lirq, lsoftirq, ltotal;
readCPU >> cpu >> luser >> lnice >> lsys >> lidle >> liowait >> lirq >> lsoftirq;
ltotal = luser + lnice + lsys + lidle + liowait + lirq + lsoftirq;
readCPU.close();
while (true)
{
sleep(2);
readCPU.open("/proc/stat", std::ifstream::in);
long user, nice, sys, idle, iowait, irq, softirq, total;
readCPU >> cpu >> user >> nice >> sys >> idle >> iowait >> irq >> softirq;
readCPU.close();
total = user + nice + sys + idle + iowait + irq + softirq;
long usage = static_cast<long>(static_cast<double>(total - ltotal - (idle - lidle)) / static_cast<double>(total - ltotal) * 100);
std::cout << "CPU使用率: " << usage << " %" << std::endl;
luser = user;
lnice = nice;
lsys = sys;
lidle = idle;
liowait = iowait;
lirq = irq;
lsoftirq = softirq;
ltotal = total;
}
}
/**
* @file getCpuTemp.cpp
* @author IYATT-yx
* @brief 获取CPU温度
* @details Raspberry Pi 4B 1.1 Raspberry Pi OS 64-bit beta (2020-8-24) C++20
*/
#include <iostream>
#include <fstream>
extern "C"
{
#include <unistd.h>
}
int main()
{
std::ifstream cpuTemp;
long temp;
while (true)
{
cpuTemp.open("/sys/class/thermal/thermal_zone0/temp", std::ifstream::in);
cpuTemp >> temp;
std::cout << "CPU温度为: " << static_cast<double>(temp) / 1000 << std::endl;
cpuTemp.close();
sleep(1);
}
}
1
/**
* @file getRamInfo.cpp
* @author IYATT-yx
* @brief 获取内存和交换分区信息
* @details Ubuntu 20.04 64-bit C++20
*/
#include <iostream>
extern "C"
{
#include <sys/sysinfo.h>
#include <unistd.h>
}
struct sysinfo sysInfo;
int main()
{
system("clear");
while (true)
{
if (sysinfo(&sysInfo) != 0)
{
std::cerr << "sysinfo Error" << std::endl;
continue;
}
unsigned long totalRAM = sysInfo.totalram >> 20;
unsigned long freeRAM = sysInfo.freeram >> 20;
unsigned long sharedRam = sysInfo.sharedram >> 20;
unsigned long buffersRam = sysInfo.bufferram >> 20;
std::cout << "total: " << totalRAM << " MB\n"
<< "free: " << freeRAM << " MB\n"
<< "shared: " << sharedRam << " MB\n"
<< "buff/cache: " << buffersRam << " MB\n" << std::endl;
unsigned long totalSwap = sysInfo.totalswap >> 20;
unsigned long freeSwap = sysInfo.freeswap >> 20;
std::cout << "total swap: " << totalSwap << " MB\n"
<< "free swap: " << freeSwap << "MB" << std::endl;
sleep(1);
system("clear");
}
}
2
/**
* @file getRamInfo.cpp
* @author IYATT-yx
* @brief 获取内存和交换分区信息
* @details Raspberry Pi 4B 1.1 Raspberry Pi OS 64-bit beta (2020-8-24) C++20
*/
#include <iostream>
#include <fstream>
#include <string>
int main()
{
std::ifstream ifs("/proc/meminfo", std::ifstream::in);
// 读取值
long value;
// 匹配项目名字 占位
std::string itemName, strNULL;
while (itemName != "MemTotal:")
{
ifs >> itemName >> value >> strNULL;
}
std::cout << "总内存: " << (value >> 10) << "MB" << std::endl;
while (itemName != "MemFree:")
{
ifs >> itemName >> value >> strNULL;
}
std::cout << "未使用内存: " << (value >> 10) << "MB" << std::endl;
while (itemName != "MemAvailable:")
{
ifs >> itemName >> value >> strNULL;
}
std::cout << "可用内存:" << (value >> 10) << "MB" << std::endl;
while (itemName != "Buffers:")
{
ifs >> itemName >> value >> strNULL;
}
std::cout << "缓冲区: " << (value >> 10) << "MB" << std::endl;
while (itemName != "Cached:")
{
ifs >> itemName >> value >> strNULL;
}
std::cout << "页高速缓存: " << (value >> 10) << "MB" << std::endl;
while (itemName != "SwapTotal:")
{
ifs >> itemName >> value >> strNULL;
}
std::cout << "交换分区总大小: " << (value >> 10) << "MB" << std::endl;
while (itemName != "SwapFree:")
{
ifs >> itemName >> value >> strNULL;
}
std::cout << "交换分区未使用大小: " << (value >> 10) << "MB" << std::endl;
}
