1.删除非空文件夹
#include <stdio.h>
#include <io.h>
#include <string.h>
#include <direct.h>
//删除文件夹目录(非空)
int removeDir(const char* dirPath)
{
struct _finddata_t fb; //查找相同属性文件的存储结构体
char path[250];
intptr_t handle;
int resultone;
int noFile; //对系统隐藏文件的处理标记
noFile = 0;
handle = 0;
//制作路径
strcpy(path, dirPath);
strcat(path, "/*");
handle = _findfirst(path, &fb);
//找到第一个匹配的文件
if (handle != 0)
{
//当可以继续找到匹配的文件，继续执行
while (0 == _findnext(handle, &fb))
{
//windows下，常有个系统文件，名为“..”,对它不做处理
noFile = strcmp(fb.name, "..");
if (0 != noFile)
{
//制作完整路径
memset(path, 0, sizeof(path));
strcpy(path, dirPath);
strcat(path, "/");
strcat(path, fb.name);
//属性值为16，则说明是文件夹，迭代
if (fb.attrib == 16)
{
removeDir(path);
}
//非文件夹的文件，直接删除。对文件属性值的情况没做详细调查，可能还有其他情况。
else
{
remove(path);
}
}
}
//关闭文件夹，只有关闭了才能删除。找这个函数找了很久，标准c中用的是closedir
//经验介绍：一般产生Handle的函数执行后，都要进行关闭的动作。
_findclose(handle);
}
//移除文件夹 ， 此时为空文件夹
//resultone = removeD(dirPath);
resultone = RemoveDirectory(dirPath);
return resultone;
}2.获取文件夹下的所有文件
tail 表示 标识已某某结尾的文件 例如 ".jpg", 两个 vector 分别表示文件的整体路径，和文件的名字
void getFiles(string path, vector<string>& files, vector<string>& filenames, const string & tail)
{
//文件句柄
intptr_t hFile = 0;
//文件信息
struct _finddata_t fileinfo;
string p;
if ((hFile = _findfirst(p.assign(path).append("\\*").c_str(), &fileinfo)) != -1)
{
do
{
//如果是目录,迭代之
//如果不是,加入列表
if ((fileinfo.attrib & _A_SUBDIR))
{
if (strcmp(fileinfo.name, ".") != 0 && strcmp(fileinfo.name, "..") != 0)
{
getFiles(p.assign(path).append("\\").append(fileinfo.name), files, filenames, tail);
}
}
else
{
string filename = fileinfo.name;
size_t found = filename.find(tail);
if (found != string::npos)
{
files.push_back(p.assign(path).append("\\").append(filename));
filenames.push_back(filename);
}
}
} while (_findnext(hFile, &fileinfo) == 0);
_findclose(hFile);
}
}3.字符串 转换为 数
template <class Type>
Type stringToNum(const string& str)
{
istringstream iss(str);
Type num;
iss >> num;
return num;
}4.字符串 分割
void splitString(const string& s, vector<string>& v, const string& c)
{
string::size_type pos1, pos2;
pos2 = s.find(c);
pos1 = 0;
while (string::npos != pos2)
{
v.push_back(s.substr(pos1, pos2 - pos1));
pos1 = pos2 + c.size();
pos2 = s.find(c, pos1);
}
if (pos1 != s.length()) {
v.push_back(s.substr(pos1));
}
}5.清除文件内容
void DataPrepareUtil::clearFileData(string filePath)
{
if (filePath == "")
{
return;
}
ofstream in;
in.open(filePath, ios::trunc);
in.close();
}6.写入文件
void DataPrepareUtil::writeDatatoFile(std::string filePath, vector<LandMark> & data, int landmark)
{
if (filePath == "" || data.size() == 0)
{
return;
}
ofstream in;
in.open(filePath, ios::app);
int length = data.size();
for (int i = 0; i < length; i++)
{
string dataline = data[i].fileName;
dataline.append(" ");
for (int j = 0; j < landmark; j++)
{
dataline.append(to_string(data[i].points[j].x));
dataline.append(" ");
dataline.append(to_string(data[i].points[j].y));
if (j != (landmark - 1))
{
dataline.append(" ");
}
//cout.precision(20);
//cout << "double x:" << data[i].points[j].x << endl;
//cout.precision(20); // 设置输出精度
//cout << "to_string():" << doubleToString(data[i].points[j].x)<<endl;
}
in << dataline << "\n";
}
in.close();
}7.读出文件
//vector<Landmark> 使用 函数参数引用 高效一些
vector<LandMark> DataPrepareUtil::readPointVisibleData(string filePath, int numMark, int count)
{
vector<LandMark> result;
ifstream fileA(filePath);
if (!fileA)
{
cout << "没有找到需要读取的 " << filePath << " 请将文件放到指定位置再次运行本程序。" << endl << " 按任意键以退出";
return result;
}
for (int i = 0; !fileA.eof() && (i < count); i++)
{
LandMark mark;
string buf;
getline(fileA, buf, '\n');
if (buf == "")
{
cout << "buf is empty." << endl;
continue;
}
parsePointVisibleData(buf, mark, numMark);
result.push_back(mark);
}
fileA.close();
return result;
}C++ 单例
//util.h文件
#ifndef _UTIL_
#define _UTIL_
#include<iostream>
#include<map>
#include <mutex>
using namespace std;
class Singleton
{
private:
string name; //第一个变量 拥有与 this 对象 同样的地址空间。
int age;
Singleton(string name, int age):name(name), age(age){}
static Singleton *instance;
static int num;
std::map<string, string> mymap;
public:
static Singleton * getInstance(string name, int age, void(*notice)());
void readData();
void removeMap(string key);
void addMap(string key, string value);
void showMap();
};
//util.cpp文件
#include "util.h"
#include <string>
using namespace std;
//必须加这两句，否者编译不通过。
Singleton* Singleton::instance = nullptr;
int Singleton::num = 1;
int static num = 2;
void * p = nullptr;
#include <mutex>
mutex mut;
condition_variable conv;
extern void notice_print();
Singleton * Singleton::getInstance(string name, int age, void (*notice)())
{
if (instance == nullptr)
{
unique_lock<mutex> loc(::mut); //持有锁 mut 其他线程在这儿会被阻塞 相当于 mut.look();
//conv.wait(loc); //释放锁等待被唤醒。 conv.notify_all(); 唤醒wait的线程
if (instance == nullptr)
{
instance = new Singleton(name, age);
notice();
notice_print();
p = &instance->name;
cout << " *p is :" << *((int *)p) << endl;
cout << " *p is :" << *((char *)p) << endl;
cout << " *p is :" << *((string *)p) << endl;
cout << " &instance :" << instance << " &name :" << p << " &age :" << &instance->age << " &num :" << &instance->num << " &mymay:" << &instance->mymap<< endl;
}
mut.unlock();
}
return instance;
}
void Singleton::readData()
{
cout << "age is:" << age << " name is: " << name << "class num is :"<< num << " global num is:" << ::num<<endl;
cout << "&this :" << this << " &name :" << &name << endl;
}
void Singleton::removeMap(string key)
{
if (mymap.count(key))
{
mymap.erase(key);
}
}
void Singleton::addMap(string key, string value)
{
if (!mymap.count(key))
{
//mymap.insert(std::pair<string, string>(key, value)); //都可以
mymap.insert(std::make_pair(key, value));
}
else
{
cout << "the key is exist." << endl;
}
}
void Singleton::showMap()
{
map<string, string>::iterator it;
it = mymap.begin();
for (it; it != mymap.end(); it++)
{
cout << "key is :" << it->first << " value is:" << it->second << endl;
}
}C++ 线程 同步
std::mutex mtx_syn;
std::condition_variable cv_syn;
std::condition_variable cv_syn_1;
bool ready = false;
void threadA(int id) {
while (1)
{ //新创建的 unique_lock 对象管理 Mutex 对象 m，并尝试调用 m.lock() 对 Mutex 对象进行上锁，如果此时另外某个 unique_lock 对象已经管理了该 Mutex 对象 m，则当前线程将会被阻塞
std::unique_lock<std::mutex> lck(mtx_syn); //lock(); 出 while循环时 就自动调用 unlock() ，也可以手动调用
while (!ready) cv_syn.wait(lck);
// ...
std::cout << "thread " << id << '\n';
Sleep(500);
cv_syn.notify_all(); //cpu 轮询执行 所有被唤醒的线程。
cv_syn.wait(lck);
}
}
void threadB(int id) {
while (1)
{
std::unique_lock<std::mutex> lck(mtx_syn);
while (!ready) cv_syn.wait(lck);
// ...
std::cout << "thread " << id << '\n';
Sleep(500);
cv_syn.notify_all();
cv_syn.wait(lck);
}
}
void threadC(int id) {
while (1)
{
std::unique_lock<std::mutex> lck(mtx_syn);
while (!ready) cv_syn_1.wait(lck);
// ...
std::cout << "thread " << id << '\n';
Sleep(500);
cv_syn_1.notify_all();
cv_syn_1.wait(lck);
}
}
void go()
{
std::unique_lock<std::mutex> lck(mtx_syn);
ready = true;
cv_syn.notify_one();
}
int main()
{
//线程同步
std::thread threads[5];
// spawn 10 threads:
//for (int i = 0; i<5; ++i)
// threads[i] = std::thread(print_id, i);
threads[0] = std::thread(threadA, 0);
threads[1] = std::thread(threadB, 1);
threads[2] = std::thread(threadC, 2);
std::cout << "2 threads ready to race...\n";
go(); // go!
for (auto& th : threads) th.join();
return 0;
}