直接访问硬盘
问题描述：
我想使用下面的代码打印引导扇区，但有错误。直接访问硬盘
#include <windows.h>
#include <stdio.h>
#include <iostream>
#include <math.h>
using namespace std;
short ReadSect
(const char * _dsk, // disk to access
char *&_buff, // buffer where sector will be stored
unsigned int _nsect // sector number, starting with 0
)
{
DWORD dwRead;
HANDLE
hDisk=CreateFile(_dsk,GENERIC_READ,FILE_SHARE_READ,0,OPEN_EXISTING,0,0);
if(hDisk==INVALID_HANDLE_VALUE) // this may happen if another program is
already reading from disk
{
CloseHandle(hDisk);
return 1;
}
SetFilePointer(hDisk,_nsect*512,0,FILE_BEGIN); // which sector to read
ReadFile(hDisk,_buff,512,&dwRead,0); // read sector
CloseHandle(hDisk);
return 0;
}
int main()
{
char * drv="\\\\.\\C:";
char *dsk=" \\\\.\\PhysicalDrive0";
int sector=0;
int b = 1;
char *buff=new char[512];
ReadSect(dsk,buff,sector);
if((unsigned char)buff[510]==0x55 && (unsigned char)buff[511]==0xaa) cout
<<"Disk is bootable!"<<endl;
else printf("%02hhX\n",(unsigned int)(unsigned char)buff[511]);
printf("\n");
while (b<513)
{
if (b%16==0)
printf(" %02hhX\n",(unsigned int)(unsigned char)buff[b-1]);
else
printf (" %02hhX ",(unsigned int)(unsigned char)buff[b-1]);
b++;
}
getchar();
}
微软视觉工作室不是打印引导扇区的十六进制数字，而是打印出“CD”流。什么是错误以及如何解决这个问题？谁能帮忙？
答
首先，启动它以管理员身份从
char *dsk=" \\\\.\\PhysicalDrive0";
删除空间必须
char *dsk="\\\\.\\PhysicalDrive0";
而且，如果你使用的char * DSK，使修改：
hDisk = CreateFile（_dsk，GENERIC_READ，FILE_SHARE_READ，0，OPEN_EXISTING，0,0）;
必须是： CreateFileA的（......）
#include <windows.h>
#include <stdio.h>
#include <iostream>
#include <math.h>
using namespace std;
short ReadSect
(const char * _dsk, // disk to access
char *&_buff, // buffer where sector will be stored
unsigned int _nsect // sector number, starting with 0
)
{
DWORD dwRead;
HANDLE
hDisk = CreateFileA(_dsk, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, 0, 0);
//CreateFile()
if (hDisk == INVALID_HANDLE_VALUE) // this may happen if another program is already reading from disk
{
CloseHandle(hDisk);
return 1;
}
SetFilePointer(hDisk, _nsect * 512, 0, FILE_BEGIN); // which sector to read
ReadFile(hDisk, _buff, 512, &dwRead, 0); // read sector
CloseHandle(hDisk);
return 0;
}
int main()
{
char * drv = "\\\\.\\C:";
char *dsk = "\\\\.\\PhysicalDrive0";
int sector = 0;
int b = 1;
char *buff = new char[512];
ReadSect(dsk, buff, sector);
if ((unsigned char)buff[510] == 0x55 && (unsigned char)buff[511] == 0xaa) cout
<< "Disk is bootable!" << endl;
else printf("%02hhX\n", (unsigned int)(unsigned char)buff[511]);
printf("\n");
while (b<513)
{
if (b % 16 == 0)
printf(" %02hhX\n", (unsigned int)(unsigned char)buff[b - 1]);
else
printf(" %02hhX ", (unsigned int)(unsigned char)buff[b - 1]);
b++;
}
getchar();
}
+0
它的工作原理！你帮了我很多！谢谢，Михайл！ Спасибобольшое！ – Nimportequi
您应该检查是否所有的函数调用成功。例如，'ReadFile'可能会失败，在这种情况下'buf'只是未初始化的内存（[MSVC初始化为0xCDCDCDCD ...或其他调试版本的值]（https://stackoverflow.com/questions/370195 /时，和为什么，意志的-OS-初始化内存到0XCD-0xdd-等-上自由的新的malloc - ））。 – Cornstalks
我在ReadFile中检查_buff的值，并在MSVC中使用调试器在ReadSect中缓冲，并显示未知符号流。在将其转换为十六进制值后，它将CDCDCDCD ...显示为输出，这意味着ReadFile或ReadSect不起作用... – Nimportequi
这不是我确保所有函数调用都成功的意思。例如，['ReadFile'返回'BOOL'，其中'TRUE'表示成功，'FALSE'表示失败]（https://msdn.microsoft.com/en-us/library/windows/desktop/aa365467（v = vs.85）的.aspx）。您应该检查所有函数调用的状态，以查看它们是否返回任何错误。 – Cornstalks