C++ 获取系统目录，自身目录，临时目录，文件读写

#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);
}