<分区>
首先，这是我看过的几个链接...
Read and write hard disk sector directly and efficiently
Read specific sector on hard drive using C language on windows
我正在尝试做几乎相同的事情。我遇到的问题是多次读取设备，因此我可以存储从设备 (USB) 读取的字节以将它们写入文件。
这就是我想要做的...
- 声明变量
- 初始化变量
- 设置文件指针()
- 读取文件()
- 将读取的字节输出到文件
- 使用 ReadFile() 获取更多字节
- 再次将读取的字节输出到同一个文件
- 重复6和7(实际上只是重复4和5)
这似乎不起作用。我想读取 x 个字节并将这些值存储到一个文件中，然后读取更多并将这些值存储在与上次相同的文件中。我希望它重复这个过程，直到它读取到设备的末尾。我希望这个程序可以在任何尺寸的设备上运行。如果我可以将它放在一个循环中，那么我就可以读取和写入无限大小的设备。
这是一个如何读/写的方法，所以我也想反过来做。读取文件中的值，然后将它们写入设备。
我使用的是 128MB USB。它包含 131858432 个字节。如果需要更多信息，我会发布。
我的代码:
#include <windows.h>
#include <stdio.h>
int main(int argc, char ** argv)
{
BYTE sector[0x400] = {0};
DWORD bytesRead;
HANDLE device = NULL;
int numSector = 1;
int maxRead = 1;
FILE *readChar = fopen("G:\\usb_128MB_Dec2.txt", "w+");
device = CreateFile("\\\\.\\L:", // Drive to open
GENERIC_READ|GENERIC_WRITE, // Access mode
FILE_SHARE_READ|FILE_SHARE_WRITE, // Share Mode
NULL, // Security Descriptor
OPEN_EXISTING, // How to create
0, // File attributes
NULL); // Handle to template
if(device == INVALID_HANDLE_VALUE)
{
printf("CreateFile: %u\n", GetLastError());
system("pause");
return 1;
}
// set the file pointer for first time
SetFilePointer(device, numSector, NULL, FILE_BEGIN);
// Edit 1. Comment 2.
if(GetLastError() != NO_ERROR)
{
printf("GetLastError: %d\n", GetLastError());
goto end; // end: is before closing files or handles at end of main()
}
// read device for maxRead number of bytes and store the reading into a file
ReadFile(device, sector, maxRead, &bytesRead, NULL);
fprintf(readChar, "%d\n", sector[0]);
// This part of code does not act like expected
SetFilePointer(device, numSector, NULL, FILE_CURRENT);
if(!ReadFile(device, sector, maxRead, &bytesRead, NULL))
printf("err\n");
else
fprintf(readChar, "%d", sector[0]);
end: // Edit 1. Comment 2.
CloseHandle(device);
fclose(readChar);
system("pause");
return 0;
}
屏幕输出:
GetLastError: 87
文件输出:
Nothing is in the file.
该文件应包含一个 8 位十进制值，而不是空值或 0。
编辑 1:
87 means INVALID PARAMETER.
Your reads have to be sector aligned so you can't seek to offset 1, but only 0, sector_size, 2sector_size, ..., nsector_size, Your reads have also be in multiplies of sector size, and your memory buffer has to be aligned to sector_size.
Sector size could be retrieved with GetDiskFreeSpace and aligned memory can be obtained with VirtualAlloc.
Maybe you should check also FSCTL_LOCK_VOLUME and FSCTL_DISMOUNT_VOLUME.
这是用于一次性读取设备的其他代码
#include <windows.h>
#include <stdio.h>
int main(int argc, char ** argv)
{
BYTE sector[0x200] = {0};
DWORD bytesRead;
HANDLE device = NULL;
int numSector = 1;
int maxRead = 0x200;
long long int i;
FILE *readChar = fopen("G:\\usb_128MB_Dec.txt", "w+");
device = CreateFile("\\\\.\\L:", // Drive to open
GENERIC_READ|GENERIC_WRITE, // Access mode
FILE_SHARE_READ|FILE_SHARE_WRITE, // Share Mode
NULL, // Security Descriptor
OPEN_EXISTING, // How to create
0, // File attributes
NULL); // Handle to template
if(device == INVALID_HANDLE_VALUE)
{
printf("CreateFile: %u\n", GetLastError());
system("pause");
return 1;
}
SetFilePointer(device, numSector, NULL, FILE_BEGIN);
if (!ReadFile(device, sector, maxRead, &bytesRead, NULL))
{
printf("ReadFile: %u\n", GetLastError());
goto end;
}
else
{
printf("Success!\n");
}
if(readChar == NULL)
{
printf("Did not open file. Exit 2.");
goto end;
}
for(i = 0; i < maxRead - 1; i++)
{
fprintf(readChar, "%d\n", sector[i]);
}
fprintf(readChar, "%d", sector[i]); // so the previous loop wont add \n to the last read wanted
end:
CloseHandle(device);
fclose(readChar);
system("pause");
return 0;
}
文件内容:
235
88
...
读取的每个字节都以十进制值形式存储在新行上。
所以它可能会更好地理解我正在尝试做的事情，这里是代码:
// What I want to do..
// This part works
SetFilePointer(device, numSector, NULL, FILE_BEGIN);
ReadFile(device, sector, maxRead, &bytesRead, NULL);
for(i = 0; i < size_of_device - 0x200; i += 512)
{
for(j = 0; j < maxRead; j++)
{
fprintf(readChar, "%d\n", sector[j]);
}
// stops working
SetFilePointer(device, numSector, NULL, FILE_CURRENT);
ReadFile(device, sector, maxRead, &bytesRead, NULL);
}
for(j = 0; j < maxRead - 1; j++)
{
fprintf(readChar, "%d\n", sector[j]);
}
fprintf(readChar, "%d", sector[j]);
// .. end of what i want to do
编辑 2:现在开始多次阅读。
#include <windows.h>
#include <stdio.h>
int main(int argc, char ** argv)
{
BYTE sector[0x200] = {0};
DWORD bytesRead;
HANDLE device = NULL;
//int numSector = 512; // original value was 1 not 512 but variable is not needed
int maxRead = 512;
int i, j, k = 0, l; // loop variables
FILE *readChar = fopen("G:\\wii u hdd image\\usb_128MB_Dec3.txt", "w+");
if(readChar == NULL)
{
printf("Error creating file.\n");
goto end;
}
device = CreateFile("\\\\.\\L:", // Drive to open
GENERIC_READ|GENERIC_WRITE, // Access mode
FILE_SHARE_READ|FILE_SHARE_WRITE, // Share Mode
NULL, // Security Descriptor
OPEN_EXISTING, // How to create
0, // File attributes
NULL); // Handle to template
// If device does not contain a handle value
if(device == INVALID_HANDLE_VALUE)
{
printf("Error. GetLastError: %u\n", GetLastError());
goto end;
}
for(i = 0; i < maxRead*503; i++) // maxRead * 503 = 257536
{
// If ReadFile() fails it will exit the program without adding a '\n' to the readChar file.
if(!ReadFile(device, sector, maxRead, &bytesRead, NULL))
{
printf("Error of ReadFile(). GetLastError(): %u\n", GetLastError());
goto end;
}
// If this is the first time through the loop then '\n' won't be added to the readChar file.
if(i != 0)
{
fprintf(readChar, "\n");
system("cls");
printf("%.2f%%\n", (i / 257536));
}
// Runs for 511 times. Then prints the 512th decimal value after the loop.
for(j = 0; j < maxRead - 1; j++)
{
fprintf(readChar, "%d\n", sector[j]);
}
fprintf(readChar, "%d", sector[j]);
}
end:
CloseHandle(device);
fclose(readChar);
system("pause");
return 0;
}
编辑 3:
这个问题在其他帖子中没有得到回答。