直接訪問硬盤

我想使用下面的代碼打印引導扇區，但有錯誤。直接訪問硬盤

#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(); 
}

微軟視覺工作室不是打印引導扇區的十六進制數字，而是打印出「CD」流。什麼是錯誤以及如何解決這個問題？誰能幫忙？

Photo of output

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2017-05-27 Nimportequi

您應該檢查是否所有的函數調用成功。例如，'ReadFile'可能會失敗，在這種情況下'buf'只是未初始化的內存（[MSVC初始化爲0xCDCDCDCD ...或其他調試版本的值]（https://stackoverflow.com/questions/370195 /時，和爲什麼，意志的-OS-初始化內存到0XCD-0xdd-等-上自由的新的malloc - ））。 – Cornstalks

我在ReadFile中檢查_buff的值，並在MSVC中使用調試器在ReadSect中緩衝，並顯示未知符號流。在將其轉換爲十六進制值後，它將CDCDCDCD ...顯示爲輸出，這意味着ReadFile或ReadSect不起作用... – Nimportequi

這不是我確保所有函數調用都成功的意思。例如，['ReadFile'返回'BOOL'，其中'TRUE'表示成功，'FALSE'表示失敗]（https://msdn.microsoft.com/en-us/library/windows/desktop/aa365467（v = vs.85）的.aspx）。您應該檢查所有函數調用的狀態，以查看它們是否返回任何錯誤。 – Cornstalks

首先，啓動它以管理員身份從

char *dsk=" \\\\.\\PhysicalDrive0";

刪除空間必須

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）;

必須是： 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(); 
}

WinAPI Unicode and ANSI functions

來源

2017-05-28 16:36:55

它的工作原理！你幫了我很多！謝謝，Михайл！ Спасибобольшое！ – Nimportequi

直接訪問硬盤

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