标签：des style 使用 os 文件 数据 io for
分区格式：NTFS / FAT32
GetSystemDirectory();//获取系统路径if(hf) FindClose(hf);
示例代码：
// winlogic.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include<STDIO.H>
#include<WINDOWS.H>
void GetLogical()
{
UINT logic=GetLogicalDrives();
printf("%d\n",logic);
}
void GetPath()
{
char txt[200]={0};
GetSystemDirectory(txt,sizeof(txt));
printf("系统路径%s\n",txt);
memset(txt,0,sizeof(txt));
GetWindowsDirectory(txt,sizeof(txt));
printf("windows路径%s\n",txt);
memset(txt,0,sizeof(txt));
GetCurrentDirectory(sizeof(txt),txt);
printf("程序工作路径%s\n",txt);
SetCurrentDirectory("c:/");
memset(txt,0,sizeof(txt));
GetCurrentDirectory(sizeof(txt),txt);
printf("更改后程序工作路径%s\n",txt);
}
void CreateWrite()
{
HANDLE hf=CreateFile("file.txt",GENERIC_WRITE,FILE_SHARE_READ,NULL,
OPEN_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL);
char txt[]="hello file to write";
DWORD len=0;//返回实际写入的长度
WriteFile(hf,txt,strlen(txt),&len,NULL);
CloseHandle(hf);
}
void Read()
{
HANDLE hf=CreateFile("file.txt",GENERIC_READ,FILE_SHARE_READ,
NULL,OPEN_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL);
CHAR txt[1000]={0};
DWORD len=0;//实际读到的长度
ReadFile(hf,txt,sizeof(txt),&len,NULL);
printf("读取到的字符串：%s\n",txt);
CloseHandle(hf);
}
void CreateDir()
{
CreateDirectory("abc/",NULL);
}
void Find()
{
char *path="c:/*.*";
WIN32_FIND_DATA wfd={0};
HANDLE hf=FindFirstFile(path,&wfd);
while(1)
{
if(wfd.dwFileAttributes&FILE_ATTRIBUTE_DIRECTORY)
{
printf("目录：[%s]\n",wfd.cFileName);
}
else
{
printf("文件：%s\n",wfd.cFileName);
}
if(FindNextFile(hf,&wfd)==0) break;
}
if(hf) FindClose(hf);
}
int main(int argc, char* argv[])
{
// GetLogical();
// GetPath();
//CreateWrite();
//Read();
//CreateDir();
Find();
char c=0;
printf("按任意键结束！\n");
scanf("%c",&c);
return 0;
}
}
堆内存Heap
GetProcessHeap-获取程序默认第一个堆
GetProcessHeaps-获取程序所有默认堆
示例：
HANDLE h1=GetProcessHeap();
HANDLE hs[256]={0};
DWORD count=GetProcessHeaps(256,hs);
HeapCreate -创建堆
HeapAlloc -从堆分配内存
-把内存还给堆
HeapDestroy -销毁堆
示例：
HANDLE h= HeapCreate(HEAP_NO_SERIALIZE,1024*1024,0);
char* p= (char*) HeapAlloc(h,HEAP_ZERO_MEMORY,2*1024*1024);
strcpy(p,"123456");
printf("%s\n",p);
HeapFree(h,0,p);
HeapDestroy(h);
如果要使用，建议用：malloc/new 和 free/delete
内存映射文件的操作，速度快：
1、先创建一个硬盘文件 CreateFile()
2、创建内存映射文件
HANDLE CreateFileMapping( HANDLE hFile, // 硬盘文件的句柄
LPSECURITY_ATTRIBUTES lpAttributes, // 传0就行
DWORD flProtect, // protection
DWORD dwMaximumSizeHigh, // 高32位大小，小于4G传0
DWORD dwMaximumSizeLow, // 低32位大小
LPCTSTR lpName // 命名，可以为NULL
);
3、获取映射文件中某部分的地址
LPVOID MapViewOfFile(
HANDLE hFileMappingObject, // 映射文件句柄
DWORD dwDesiredAccess, // 访问权限
DWORD dwFileOffsetHigh, // 高32位大小，小于4G传0
DWORD dwFileOffsetLow, // 低32位大小
SIZE_T dwNumberOfBytesToMap // 映射的字节数量
);
dwFileOffsetHigh和dwFileOffsetLow 的合成必须是64K的整数倍。
4、断开地址和映射文件某部分
BOOL UnmapViewOfFile( LPCVOID lpBaseAddress//
);
5、关闭映射文件
CloseHandle(HANDLE)
6、关闭硬盘文件
CloseHandle(HANDLE);
示例：
HANDLE file=CreateFile("file.txt",GENERIC_READ|GENERIC_WRITE,FILE_SHARE_READ,
0,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL);
HANDLE map=CreateFileMapping(file,0,PAGE_READWRITE,0,1024*1024,"pkm");
//
char* p=(char*)MapViewOfFile(map,FILE_MAP_ALL_ACCESS,0,64*1024,0);
strcpy(p,"adsadsad asd as d\n as d a\n s d as d a s aaaaa bbbbb ccccc\n");
printf("%s\n",p);
UnmapViewOfFile(p);
getchar();
CloseHandle(map);//关闭就没了，如果其他进程要使用，则不能关。
CloseHandle(file);//关闭了还在硬盘上
其他进程获取本进程已经创建好的映射文件，不能提前关闭映射文件
HANDLE OpenFileMapping( DWORD dwDesiredAccess, // access mode
BOOL bInheritHandle, // 返回值能否被子进程使用
LPCTSTR lpName // 映射名称
);
示例：
HANDLE map=OpenFileMapping(FILE_MAP_ALL_ACCESS,FALSE,"pkm");
char* p=(char*)MapViewOfFile(map,FILE_MAP_ALL_ACCESS,0,64*1024,0);
printf("%s\n",p);
UnmapViewOfFile(p);
示例代码：
// winVirtual.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include<STDIO.H>
#include <WINDOWS.H>
void ShowMemStatus()
{
MEMORYSTATUS mm;
mm.dwLength=sizeof(mm);
GlobalMemoryStatus(&mm);
printf("内存使用率:%d/100\n",mm.dwMemoryLoad);
printf("TotalPhys:%u MB\n",mm.dwTotalPhys/1024/1024);
printf("AvaliPhys:%u MB\n",mm.dwAvailPhys/1024/1024);
printf("TotalVirtual:%u MB\n",mm.dwTotalPageFile/1024/1024);
printf("AvaliVirtual:%u MB\n",mm.dwAvailPageFile/1024/1024);
printf("TotalAddr:%u MB\n",mm.dwTotalVirtual/1024/1024);
printf("AvaliAddr:%u MB\n",mm.dwAvailVirtual/1024/1024);
}
void Virtual_info()
{
ShowMemStatus();
char* p=(char*)VirtualAlloc(NULL,1024*1024*1024,MEM_COMMIT,PAGE_READWRITE);
ShowMemStatus();
VirtualFree(p,0,MEM_RELEASE);
ShowMemStatus();
}
void Virtual_commit()
{
char* p=(char*) VirtualAlloc(NULL,4096,MEM_COMMIT,PAGE_READWRITE);
strcpy(p,"HELLO MEMORY");
printf("%s\n",p);
VirtualFree(p,0,MEM_RELEASE);
}
void Virtual_reserve()
{
//申请地址，不分配内存
char* p =(char*) VirtualAlloc(NULL,1024*1024,MEM_RESERVE,PAGE_READWRITE);
char* p1=(char*)VirtualAlloc(p,4096,MEM_COMMIT,PAGE_READWRITE);//提交内存，以一个内存页4k为最小单位
strcpy(p,"HELLO MEMORY");
printf("%s\n",p);
VirtualFree(p,0,MEM_RELEASE);
}
void HeapInfo()
{
HANDLE h1=GetProcessHeap();
printf("h1-%d\n",h1);
HANDLE hs[256]={0};
DWORD count=GetProcessHeaps(256,hs);
for(int i=0;i<count;i++)
{
printf("%d-%d\n",i,hs[i]);
}
}
void MyHead()
{
HANDLE h= HeapCreate(HEAP_NO_SERIALIZE,1024*1024,0);
char* p= (char*) HeapAlloc(h,HEAP_ZERO_MEMORY,2*1024*1024);
strcpy(p,"123456");
printf("%s\n",p);
HeapFree(h,0,p);
HeapDestroy(h);
}
void FileMap()
{
HANDLE file=CreateFile("file.txt",GENERIC_READ|GENERIC_WRITE,FILE_SHARE_READ,
0,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL);
HANDLE map=CreateFileMapping(file,0,PAGE_READWRITE,0,1024*1024,"pkm");
//
char* p=(char*)MapViewOfFile(map,FILE_MAP_ALL_ACCESS,0,64*1024,0);
strcpy(p,"adsadsad asd as d\n as d a\n s d as d a s aaaaa bbbbb ccccc\n");
printf("%s\n",p);
UnmapViewOfFile(p);
getchar();
CloseHandle(map);//关闭就没了，如果其他进程要使用，则不能关。
CloseHandle(file);//关闭了还在硬盘上
}
void ReadFileMap()
{
HANDLE map=OpenFileMapping(FILE_MAP_ALL_ACCESS,FALSE,"pkm");
char* p=(char*)MapViewOfFile(map,FILE_MAP_ALL_ACCESS,0,64*1024,0);
printf("%s\n",p);
UnmapViewOfFile(p);
CloseHandle(map);//关闭就没了
}
int main(int argc, char* argv[])
{
//Virtual_info();
//Virtual_commit();
//Virtual_reserve();
//HeapInfo();
//MyHead();
FileMap();
//ReadFileMap();
return 0;
}
c++windows内核编程笔记day12 硬盘逻辑分区管理、文件管理、内存管理,布布扣,bubuko.com
c++windows内核编程笔记day12 硬盘逻辑分区管理、文件管理、内存管理
标签：des style 使用 os 文件 数据 io for
原文地址：http://blog.csdn.net/pukuimin1226/article/details/38227843
