# C++ 获取系统目录，自身目录，临时目录，文件读写


@[TOC](博文目录)



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## 正文


#include "stdafx.h"
#include <stdlib.h> 
#include <stdio.h>
#include <iostream.h>
#include <windows.h>
#include <memory.h>
#include <string.h>
int WriteFile();

int main(int argc, char* argv[])
{
    //获取系统temp目录
    char    strTmpPath[MAX_PATH];
    GetTempPath(sizeof(strTmpPath), strTmpPath);
    printf("获取系统temp目录：%s\n",strTmpPath);

    // 获取自身的绝对路径
    char    strSelf[MAX_PATH];
    memset(strSelf, 0, sizeof(strSelf));
    GetModuleFileName(NULL, strSelf, sizeof(strSelf));
    printf("获取自身的绝对路径：%s\n", strSelf);

    //获取当前进程号
    printf("获取当前进程号：%d\n",GetCurrentThreadId());

    // 获取系统目录
    char strSysDir[100];
    GetSystemDirectory(strSysDir, sizeof(strSysDir));
    // char *bin = "%SystemRoot%\\System32\\svchost.exe -k netsvcs";
    printf("系统目录：%s\n",strSysDir);

    //采用：CreateFile、ReadFile、WriteFile读写文件
    WriteFile();
    //采用fread、fwrite
    system("pause");
    return 0;
}


int WriteFile()
{

DWORD dwFileSize = 0;

    BYTE* buffer = NULL;

    HANDLE hFile = INVALID_HANDLE_VALUE;

    hFile = CreateFile("E:\\123.txt",GENERIC_READ,
                       FILE_SHARE_READ,NULL,OPEN_EXISTING,
                       FILE_ATTRIBUTE_NORMAL,NULL);

    if (hFile == INVALID_HANDLE_VALUE)
    {
        CloseHandle(hFile);

        printf("Create File Failed !\n");
        return 0;
    } 
    else
    {
        dwFileSize = GetFileSize(hFile,NULL);
        //LARGE_INTEGER lFileSize;
        //GetFileSizeEx(hFile,&lFileSize);//若文件长度超过0xFFFFFFFF，使用GetFileSizeEx。
        printf("%d\n",dwFileSize);

        buffer = new BYTE[dwFileSize];
        if (buffer == NULL)
        {
            printf("Create buffer error !\n");
            return 0;
        }
        ZeroMemory(buffer,dwFileSize);

        DWORD dwReadSize = 0,dwReadTotal = 0;

        while (dwReadTotal < dwFileSize)
        {
            ReadFile(hFile,buffer + dwReadTotal,dwFileSize - dwReadSize,&dwReadSize,NULL);
            dwReadTotal += dwReadSize;
        }
        printf("总共读取的文件大小:%d\n:",dwReadTotal);
    }

    hFile = CreateFile("E:\\方式一.txt",GENERIC_WRITE,0,NULL,               
        CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL);
    if (hFile == INVALID_HANDLE_VALUE)
    {
        CloseHandle(hFile);
        printf("Create File Failed -2 !\n");
        delete []buffer;
        buffer = NULL;
        return 0;
    } 
    else
    {
        DWORD dwWriteTotal = 0,dwWriteSize = 0;
        while (dwWriteTotal < dwFileSize)
        {
            WriteFile(hFile,buffer + dwWriteTotal,dwFileSize,&dwWriteSize,NULL);
            dwWriteTotal += dwWriteSize;
        }
    }
    delete []buffer;
    buffer = NULL;
    CloseHandle(hFile);
}

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