在 Windows 上，您只能看到可移动媒体上的第一个分区。我想编写一个 C++ 程序，可以将包含一个 MBR 和 2 个数据分区的图像写入 USB 闪存驱动器。我不需要第二个分区在 Windows 中可见 - 我只需要能够从 Windows/C++ 将此原始图像写入 USB 闪存驱动器，以便稍后在 Linux 上运行时可以看到这两个分区。
我读过有关安装过滤器驱动程序的信息，该驱动程序最终会将可移动媒体视为固定媒体，这对于阅读来说很不错，但我只想在写入此图像时尽量减少对用户 PC 的干扰。我可以从第一个扇区开始访问原始 USB 驱动器，然后只写入 MBR，然后写入两个数据分区吗？
最佳答案
如果您有足够的权限这样做，您可以使用 CreateFile 打开句柄以直接写入 USB 驱动器。文件名类似于 \\.\PhysicalDrive2。
您需要计算出物理驱动器编号。如果您有驱动器盘符，则可以使用类似 \\?\D: 的文件名打开卷句柄，然后使用 IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS以确定与卷关联的物理驱动器编号。
您可能需要先卸载现有的卷(如果有的话)。我不确定最好的方法是什么，但您可以尝试使用 IOCTL_VOLUME_OFFLINE .
编辑:这是我用于磁盘镜像的一些代码，尽管我不记得是否曾在 USB 磁盘上尝试过。公共(public)领域，但没有明示或暗示的保证等。(查看代码我注意到我没有明确检查扇区大小以确保缓冲区和读/写操作正确对齐。这不应该'在实践中这不是问题，因为通常使用的最大扇区大小是 4K，这也是 Windows 上的内存页面大小。但是，在生产代码中，您应该始终明确确定相关设备的扇区大小并确保正确对齐相应地。)
#define _WIN32_WINNT 0x0501
#include <windows.h>
#include <stdio.h>
#define dump_buffersize_megs 16
#define dump_buffersize (dump_buffersize_megs * 1024 * 1024)
#define dump_workingsetsize ((dump_buffersize_megs + 1) * 1024 * 1024)
DWORD save(const wchar_t * source_device_name, const wchar_t * filename) {
DWORD err;
HANDLE hdevice, houtput;
DWORD bytes_to_transfer, byte_count;
GET_LENGTH_INFORMATION source_disklength;
DISK_GEOMETRY source_diskgeometry;
LARGE_INTEGER offset;
OVERLAPPED overlapped;
BYTE * buffer;
if (!SetProcessWorkingSetSize(GetCurrentProcess(), dump_workingsetsize, dump_workingsetsize))
{
err = GetLastError();
printf("Error %u trying to expand working set.\n", err);
return err;
}
buffer = VirtualAlloc(NULL, dump_buffersize, MEM_COMMIT, PAGE_READWRITE);
if (buffer == NULL)
{
err = GetLastError();
printf("Error %u trying to allocate buffer.\n", err);
return err;
}
if (!VirtualLock(buffer, dump_buffersize))
{
err = GetLastError();
printf("Error %u trying to lock buffer.\n", err);
return err;
}
hdevice = CreateFile
(
source_device_name,
GENERIC_READ,
0,
NULL,
OPEN_EXISTING,
FILE_FLAG_NO_BUFFERING,
NULL
);
if (hdevice == INVALID_HANDLE_VALUE) {
err = GetLastError();
fprintf(stderr, "Error %u opening input device.\n", err);
return err;
}
if (!DeviceIoControl
(
hdevice,
FSCTL_LOCK_VOLUME,
NULL,
0,
NULL,
0,
&byte_count,
NULL
))
{
err = GetLastError();
fprintf(stderr, "Error %u locking input volume.\n", err);
return err;
}
if (!DeviceIoControl
(
hdevice,
IOCTL_DISK_GET_DRIVE_GEOMETRY,
NULL,
0,
&source_diskgeometry,
sizeof(source_diskgeometry),
&byte_count,
NULL
))
{
err = GetLastError();
fprintf(stderr, "Error %u getting device geometry.\n", err);
return err;
}
switch (source_diskgeometry.MediaType)
{
case Unknown:
case RemovableMedia:
case FixedMedia:
if (!DeviceIoControl
(
hdevice,
IOCTL_DISK_GET_LENGTH_INFO,
NULL,
0,
&source_disklength,
sizeof(source_disklength),
&byte_count,
NULL
))
{
err = GetLastError();
fprintf(stderr, "Error %u getting input device length.\n", err);
return err;
}
fprintf(stderr, "\nInput disk has %I64i bytes.\n\n", source_disklength.Length.QuadPart);
break;
default:
source_disklength.Length.QuadPart =
source_diskgeometry.Cylinders.QuadPart *
source_diskgeometry.TracksPerCylinder *
source_diskgeometry.SectorsPerTrack *
source_diskgeometry.BytesPerSector;
fprintf(stderr,
"\n"
"Input device appears to be a floppy disk. WARNING: if this is not a\n"
"floppy disk the calculated size will probably be incorrect, resulting\n"
"in an incomplete copy.\n"
"\n"
"Input disk has %I64i bytes.\n"
"\n",
source_disklength.Length.QuadPart);
break;
}
houtput = CreateFile
(
filename,
GENERIC_WRITE,
0,
NULL,
CREATE_ALWAYS,
FILE_FLAG_NO_BUFFERING | FILE_FLAG_OVERLAPPED,
NULL
);
if (houtput == INVALID_HANDLE_VALUE)
{
err = GetLastError();
fprintf(stderr, "Error %u creating output file.\n", err);
return err;
}
offset.QuadPart = 0;
overlapped.hEvent = 0;
for (;;)
{
overlapped.Offset = offset.LowPart;
overlapped.OffsetHigh = offset.HighPart;
if (source_disklength.Length.QuadPart - offset.QuadPart < dump_buffersize)
{
bytes_to_transfer = (DWORD)(source_disklength.Length.QuadPart - offset.QuadPart);
if (bytes_to_transfer == 0) break;
}
else
{
bytes_to_transfer = dump_buffersize;
}
if (!ReadFile(hdevice, buffer, bytes_to_transfer, NULL, &overlapped))
{
err = GetLastError();
printf("Error %u initiating read from input disk.\n", err);
return err;
}
if (!GetOverlappedResult(hdevice, &overlapped, &byte_count, TRUE))
{
err = GetLastError();
printf("Error %u reading from input disk.\n", err);
return err;
}
if (byte_count != bytes_to_transfer)
{
err = GetLastError();
printf("Internal error - partial read. Last error code %u.\n", err);
printf("bytes_to_transfer = %u; byte_count = %u.\n", bytes_to_transfer, byte_count);
if (byte_count == 0) return ERROR_INVALID_FUNCTION;
bytes_to_transfer = byte_count;
}
if (!WriteFile(houtput, buffer, bytes_to_transfer, NULL, &overlapped))
{
err = GetLastError();
if (err != ERROR_IO_PENDING)
{
printf("Error %u initiating write to output file.\n", err);
return err;
}
}
if (!GetOverlappedResult(houtput, &overlapped, &byte_count, TRUE))
{
err = GetLastError();
printf("Error %u writing to output file.\n", err);
return err;
}
if (byte_count != bytes_to_transfer)
{
printf("Internal error - partial write.\n");
printf("bytes_to_transfer = %u; byte_count = %u.\n", bytes_to_transfer, byte_count);
return ERROR_INVALID_FUNCTION;
}
offset.QuadPart += bytes_to_transfer;
}
overlapped.Offset = offset.LowPart;
overlapped.OffsetHigh = offset.HighPart;
if (!ReadFile(hdevice, buffer, source_diskgeometry.BytesPerSector, NULL, &overlapped))
{
err = GetLastError();
if (err == ERROR_HANDLE_EOF)
{
printf("Save successfully completed.\n");
return 0;
}
printf("Error %u initiating read from input disk past end of file.\n", err);
return err;
}
if (!GetOverlappedResult(hdevice, &overlapped, &byte_count, TRUE))
{
err = GetLastError();
if (err == ERROR_HANDLE_EOF)
{
printf("Save successfully completed.\n");
return 0;
}
printf("Error %u reading from input disk past end of file.\n", err);
return err;
}
if (byte_count == 0)
{
printf("Save successfully completed.\n");
return 0;
}
printf("WARNING: the expected amount of data was successfully copied,\n"
"but end of file not detected on input disk. The copy might\n"
"not be complete.");
return ERROR_MORE_DATA;
}
DWORD write(const wchar_t * filename, const wchar_t * target_device_name) {
DWORD err;
HANDLE hinput, houtput;
WIN32_FILE_ATTRIBUTE_DATA fad;
DWORD bytes_to_transfer, byte_count;
LARGE_INTEGER filelength;
GET_LENGTH_INFORMATION target_disklength;
DISK_GEOMETRY target_diskgeometry;
LARGE_INTEGER transfer_length;
LARGE_INTEGER offset;
OVERLAPPED overlapped;
BYTE * buffer;
if (!SetProcessWorkingSetSize(GetCurrentProcess(), dump_workingsetsize, dump_workingsetsize))
{
err = GetLastError();
printf("Error %u trying to expand working set.\n", err);
return err;
}
buffer = VirtualAlloc(NULL, dump_buffersize, MEM_COMMIT, PAGE_READWRITE);
if (buffer == NULL)
{
err = GetLastError();
printf("Error %u trying to allocate buffer.\n", err);
return err;
}
if (!VirtualLock(buffer, dump_buffersize))
{
err = GetLastError();
printf("Error %u trying to lock buffer.\n", err);
return err;
}
if (!GetFileAttributesEx(filename, GetFileExInfoStandard, &fad))
{
err = GetLastError();
fprintf(stderr, "Error %u reading input file attributes.\n", err);
return err;
}
filelength.HighPart = fad.nFileSizeHigh;
filelength.LowPart = fad.nFileSizeLow;
fprintf(stderr, "\nInput file has %I64i bytes.\n", filelength.QuadPart);
hinput = CreateFile
(
filename,
GENERIC_READ,
0,
NULL,
OPEN_EXISTING,
FILE_FLAG_NO_BUFFERING | FILE_FLAG_OVERLAPPED,
NULL
);
if (hinput == INVALID_HANDLE_VALUE)
{
err = GetLastError();
fprintf(stderr, "Error %u opening input file.\n", err);
return err;
}
houtput = CreateFile
(
target_device_name,
GENERIC_READ | GENERIC_WRITE,
0,
NULL,
OPEN_EXISTING,
FILE_FLAG_NO_BUFFERING,
NULL
);
if (houtput == INVALID_HANDLE_VALUE) {
err = GetLastError();
fprintf(stderr, "Error %u opening output device.\n", err);
return err;
}
if (!DeviceIoControl
(
houtput,
FSCTL_LOCK_VOLUME,
NULL,
0,
NULL,
0,
&byte_count,
NULL
))
{
err = GetLastError();
fprintf(stderr, "Error %u locking volume.\n", err);
return err;
}
if (!DeviceIoControl
(
houtput,
IOCTL_DISK_GET_DRIVE_GEOMETRY,
NULL,
0,
&target_diskgeometry,
sizeof(target_diskgeometry),
&byte_count,
NULL
))
{
err = GetLastError();
fprintf(stderr, "Error %u getting output device geometry.\n", err);
return err;
}
switch (target_diskgeometry.MediaType)
{
case Unknown:
case RemovableMedia:
case FixedMedia:
if (!DeviceIoControl
(
houtput,
IOCTL_DISK_GET_LENGTH_INFO,
NULL,
0,
&target_disklength,
sizeof(target_disklength),
&byte_count,
NULL
))
{
err = GetLastError();
fprintf(stderr, "Error %u getting output device length.\n", err);
return err;
}
fprintf(stderr, "Output disk has %I64i bytes.\n\n", target_disklength.Length.QuadPart);
break;
default:
target_disklength.Length.QuadPart =
target_diskgeometry.Cylinders.QuadPart *
target_diskgeometry.TracksPerCylinder *
target_diskgeometry.SectorsPerTrack *
target_diskgeometry.BytesPerSector;
fprintf(stderr,
"\n"
"Output device appears to be a floppy disk. WARNING: if this is not a\n"
"floppy disk the calculated output device size is probably incorrect,\n"
"which might result in an incomplete copy.\n"
"\n"
"Output disk has %I64i bytes.\n"
"\n",
target_disklength.Length.QuadPart);
break;
}
if (filelength.QuadPart == target_disklength.Length.QuadPart)
{
transfer_length.QuadPart = filelength.QuadPart;
}
else if (filelength.QuadPart < target_disklength.Length.QuadPart)
{
fprintf(stderr, "Image is smaller than target. Part of the target will not be written to.\n\n");
transfer_length.QuadPart = filelength.QuadPart;
}
else
{
fprintf(stderr, "Image is larger than target. Part of the image will not be copied.\n\n");
transfer_length.QuadPart = target_disklength.Length.QuadPart;
}
offset.QuadPart = 0;
overlapped.hEvent = 0;
for (;;)
{
overlapped.Offset = offset.LowPart;
overlapped.OffsetHigh = offset.HighPart;
if (transfer_length.QuadPart - offset.QuadPart < dump_buffersize)
{
bytes_to_transfer = (DWORD)(transfer_length.QuadPart - offset.QuadPart);
if (bytes_to_transfer == 0) break;
}
else
{
bytes_to_transfer = dump_buffersize;
}
if (!ReadFile(hinput, buffer, bytes_to_transfer, NULL, &overlapped))
{
err = GetLastError();
if (err != ERROR_IO_PENDING)
{
printf("Error %u initiating read from input file.\n", err);
return err;
}
}
if (!GetOverlappedResult(hinput, &overlapped, &byte_count, TRUE))
{
err = GetLastError();
printf("Error %u reading from input file.\n", err);
return err;
}
if (byte_count != bytes_to_transfer)
{
err = GetLastError();
printf("Internal error - partial read. Last error code %u.\n", err);
printf("bytes_to_transfer = %u; byte_count = %u.\n", bytes_to_transfer, byte_count);
if (byte_count == 0) return ERROR_INVALID_FUNCTION;
bytes_to_transfer = byte_count;
}
if (!WriteFile(houtput, buffer, bytes_to_transfer, NULL, &overlapped))
{
err = GetLastError();
if (err != ERROR_IO_PENDING)
{
printf("Error %u initiating write to output disk.\n", err);
return err;
}
}
if (!GetOverlappedResult(houtput, &overlapped, &byte_count, TRUE))
{
err = GetLastError();
printf("Error %u writing to output disk.\n", err);
return err;
}
if (byte_count != bytes_to_transfer)
{
printf("Internal error - partial write.\n");
printf("bytes_to_transfer = %u; byte_count = %u.\n", bytes_to_transfer, byte_count);
return ERROR_INVALID_FUNCTION;
}
offset.QuadPart += bytes_to_transfer;
}
printf("Write successfully completed.\n");
return 0;
}
DWORD clone(const wchar_t * source_device_name, const wchar_t * target_device_name) {
DWORD err;
HANDLE hinput, houtput;
DWORD bytes_to_transfer, byte_count;
GET_LENGTH_INFORMATION source_disklength;
DISK_GEOMETRY source_diskgeometry;
GET_LENGTH_INFORMATION target_disklength;
DISK_GEOMETRY target_diskgeometry;
LARGE_INTEGER transfer_length;
LARGE_INTEGER offset;
OVERLAPPED overlapped;
BYTE * buffer;
DWORD result;
if (!SetProcessWorkingSetSize(GetCurrentProcess(), dump_workingsetsize, dump_workingsetsize))
{
err = GetLastError();
printf("Error %u trying to expand working set.\n", err);
return err;
}
buffer = VirtualAlloc(NULL, dump_buffersize, MEM_COMMIT, PAGE_READWRITE);
if (buffer == NULL)
{
err = GetLastError();
printf("Error %u trying to allocate buffer.\n", err);
return err;
}
if (!VirtualLock(buffer, dump_buffersize))
{
err = GetLastError();
printf("Error %u trying to lock buffer.\n", err);
return err;
}
hinput = CreateFile
(
source_device_name,
GENERIC_READ,
0,
NULL,
OPEN_EXISTING,
FILE_FLAG_NO_BUFFERING,
NULL
);
if (hinput == INVALID_HANDLE_VALUE) {
err = GetLastError();
fprintf(stderr, "Error %u opening input device.\n", err);
return err;
}
if (!DeviceIoControl
(
hinput,
FSCTL_LOCK_VOLUME,
NULL,
0,
NULL,
0,
&byte_count,
NULL
))
{
err = GetLastError();
fprintf(stderr, "Error %u locking input volume.\n", err);
return err;
}
if (!DeviceIoControl
(
hinput,
IOCTL_DISK_GET_DRIVE_GEOMETRY,
NULL,
0,
&source_diskgeometry,
sizeof(source_diskgeometry),
&byte_count,
NULL
))
{
err = GetLastError();
fprintf(stderr, "Error %u getting device geometry.\n", err);
return err;
}
switch (source_diskgeometry.MediaType)
{
case Unknown:
case RemovableMedia:
case FixedMedia:
if (!DeviceIoControl
(
hinput,
IOCTL_DISK_GET_LENGTH_INFO,
NULL,
0,
&source_disklength,
sizeof(source_disklength),
&byte_count,
NULL
))
{
err = GetLastError();
fprintf(stderr, "Error %u getting input device length.\n", err);
return err;
}
fprintf(stderr, "\nInput disk has %I64i bytes.\n", source_disklength.Length.QuadPart);
break;
default:
source_disklength.Length.QuadPart =
source_diskgeometry.Cylinders.QuadPart *
source_diskgeometry.TracksPerCylinder *
source_diskgeometry.SectorsPerTrack *
source_diskgeometry.BytesPerSector;
fprintf(stderr,
"\n"
"Input device appears to be a floppy disk. WARNING: if this is not a\n"
"floppy disk the calculated disk size is probably incorrect, resulting\n"
"in an incomplete copy.\n"
"\n"
"Input disk has %I64i bytes.\n",
source_disklength.Length.QuadPart);
break;
}
houtput = CreateFile
(
target_device_name,
GENERIC_READ | GENERIC_WRITE,
0,
NULL,
OPEN_EXISTING,
FILE_FLAG_NO_BUFFERING,
NULL
);
if (houtput == INVALID_HANDLE_VALUE) {
err = GetLastError();
fprintf(stderr, "Error %u opening output device.\n", err);
return err;
}
if (!DeviceIoControl
(
houtput,
FSCTL_LOCK_VOLUME,
NULL,
0,
NULL,
0,
&byte_count,
NULL
))
{
err = GetLastError();
fprintf(stderr, "Error %u locking output volume.\n", err);
return err;
}
if (!DeviceIoControl
(
houtput,
IOCTL_DISK_GET_DRIVE_GEOMETRY,
NULL,
0,
&target_diskgeometry,
sizeof(target_diskgeometry),
&byte_count,
NULL
))
{
err = GetLastError();
fprintf(stderr, "Error %u getting output device geometry.\n", err);
return err;
}
switch (target_diskgeometry.MediaType)
{
case Unknown:
case RemovableMedia:
case FixedMedia:
if (!DeviceIoControl
(
houtput,
IOCTL_DISK_GET_LENGTH_INFO,
NULL,
0,
&target_disklength,
sizeof(target_disklength),
&byte_count,
NULL
))
{
err = GetLastError();
fprintf(stderr, "Error %u getting output device length.\n", err);
return err;
}
fprintf(stderr, "Output disk has %I64i bytes.\n\n", target_disklength.Length.QuadPart);
break;
default:
target_disklength.Length.QuadPart =
target_diskgeometry.Cylinders.QuadPart *
target_diskgeometry.TracksPerCylinder *
target_diskgeometry.SectorsPerTrack *
target_diskgeometry.BytesPerSector;
fprintf(stderr,
"\n"
"Output device appears to be a floppy disk. WARNING: if this is not a\n"
"floppy disk the calculated output device size is probably incorrect,\n"
"which might result in an incomplete copy.\n"
"\n"
"Output disk has %I64i bytes.\n"
"\n",
target_disklength.Length.QuadPart);
break;
}
if (source_disklength.Length.QuadPart == target_disklength.Length.QuadPart)
{
transfer_length.QuadPart = source_disklength.Length.QuadPart;
}
else if (source_disklength.Length.QuadPart < target_disklength.Length.QuadPart)
{
printf("Input shorter than output. Part of the output disk will not be written to.\n\n");
transfer_length.QuadPart = source_disklength.Length.QuadPart;
}
else
{
printf("Output shorter than input. Copy will be truncated to output length.\n\n");
transfer_length.QuadPart = target_disklength.Length.QuadPart;
}
offset.QuadPart = 0;
overlapped.hEvent = 0;
for (;;)
{
overlapped.Offset = offset.LowPart;
overlapped.OffsetHigh = offset.HighPart;
if (transfer_length.QuadPart - offset.QuadPart < dump_buffersize)
{
bytes_to_transfer = (DWORD)(transfer_length.QuadPart - offset.QuadPart);
if (bytes_to_transfer == 0) break;
}
else
{
bytes_to_transfer = dump_buffersize;
}
if (!ReadFile(hinput, buffer, bytes_to_transfer, NULL, &overlapped))
{
err = GetLastError();
printf("Error %u initiating read from input file.\n", err);
return err;
}
if (!GetOverlappedResult(hinput, &overlapped, &byte_count, TRUE))
{
err = GetLastError();
printf("Error %u reading from input file.\n", err);
return err;
}
if (byte_count != bytes_to_transfer)
{
err = GetLastError();
printf("Internal error - partial read. Last error code %u.\n", err);
printf("bytes_to_transfer = %u; byte_count = %u.\n", bytes_to_transfer, byte_count);
if (byte_count == 0) return ERROR_INVALID_FUNCTION;
bytes_to_transfer = byte_count;
}
if (!WriteFile(houtput, buffer, bytes_to_transfer, NULL, &overlapped))
{
err = GetLastError();
if (err != ERROR_IO_PENDING)
{
printf("Error %u initiating write to output disk.\n", err);
return err;
}
}
if (!GetOverlappedResult(houtput, &overlapped, &byte_count, TRUE))
{
err = GetLastError();
printf("Error %u writing to output disk.\n", err);
return err;
}
if (byte_count != bytes_to_transfer)
{
printf("Internal error - partial write.\n");
printf("bytes_to_transfer = %u; byte_count = %u.\n", bytes_to_transfer, byte_count);
return ERROR_INVALID_FUNCTION;
}
offset.QuadPart += bytes_to_transfer;
}
if (transfer_length.QuadPart == source_disklength.Length.QuadPart)
{
overlapped.Offset = offset.LowPart;
overlapped.OffsetHigh = offset.HighPart;
if (!ReadFile(hinput, buffer, source_diskgeometry.BytesPerSector, NULL, &overlapped))
{
err = GetLastError();
if (err == ERROR_HANDLE_EOF)
{
printf("Copy successfully completed.\n");
return 0;
}
printf("Error %u initiating read from input disk past end of file.\n", err);
return err;
}
if (!GetOverlappedResult(hinput, &overlapped, &byte_count, TRUE))
{
err = GetLastError();
if (err == ERROR_HANDLE_EOF)
{
printf("Copy successfully completed.\n");
return 0;
}
printf("Error %u reading from input disk past end of file.\n", err);
return err;
}
if (byte_count == 0)
{
printf("Copy successfully completed.\n");
return 0;
}
printf("WARNING: the expected amount of data was successfully copied,\n"
"but end of file not detected on input disk. The copy might\n"
"not be complete.");
result = ERROR_MORE_DATA;
return 0;
}
printf("Copy successfully completed.\n");
return 0;
}
int wmain(int argc, wchar_t ** argv)
{
if (argc < 4)
{
printf("Syntax: \n"
"To save an image of a physical drive:\n"
"diskimage /save \\\\.\\PhysicalDrive0 file.img\n"
"diskimage /save \\\\.\\A: file.img\n"
"To write from an image file to a physical drive:\n"
"diskimage /write file.img \\\\.\\PhysicalDrive0\n"
"diskimage /write file.img \\\\.\\A:\n"
"To clone input drive 0 to output drive 1:\n"
"diskimage /clone \\\\.\\PhysicalDrive0 \\\\.\\PhysicalDrive1\n"
);
return 1;
}
if (_wcsicmp(argv[1], L"/save") == 0)
{
return save(argv[2], argv[3]);
}
else if (_wcsicmp(argv[1], L"/write") == 0)
{
return write(argv[2], argv[3]);
}
else if (_wcsicmp(argv[1], L"/clone") == 0)
{
return clone(argv[2], argv[3]);
}
else
{
printf("Invalid argument. Use /? for syntax help.\n");
return 1;
}
}
关于c++ - 如何使用 C++ 在 Windows 上将包含多个分区的图像写入 U 盘，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/15004984/
我正在学习如何使用Nokogiri，根据这段代码我遇到了一些问题:require'rubygems'require'mechanize'post_agent=WWW::Mechanize.newpost_page=post_agent.get('http://www.vbulletin.org/forum/showthread.php?t=230708')puts"\nabsolutepathwithtbodygivesnil"putspost_page.parser.xpath('/html/body/div/div/div/div/div/table/tbody/tr/td/div
总的来说，我对ruby还比较陌生，我正在为我正在创建的对象编写一些rspec测试用例。许多测试用例都非常基础，我只是想确保正确填充和返回值。我想知道是否有办法使用循环结构来执行此操作。不必为我要测试的每个方法都设置一个assertEquals。例如:describeitem,"TestingtheItem"doit"willhaveanullvaluetostart"doitem=Item.new#HereIcoulddotheitem.name.shouldbe_nil#thenIcoulddoitem.category.shouldbe_nilendend但我想要一些方法来使用
我有一个Ruby程序，它使用rubyzip压缩XML文件的目录树。gem。我的问题是文件开始变得很重，我想提高压缩级别，因为压缩时间不是问题。我在rubyzipdocumentation中找不到一种为创建的ZIP文件指定压缩级别的方法。有人知道如何更改此设置吗？是否有另一个允许指定压缩级别的Ruby库？ 最佳答案 这是我通过查看rubyzip内部创建的代码。level=Zlib::BEST_COMPRESSIONZip::ZipOutputStream.open(zip_file)do|zip|Dir.glob("**/*")d
类classAprivatedeffooputs:fooendpublicdefbarputs:barendprivatedefzimputs:zimendprotecteddefdibputs:dibendendA的实例a=A.new测试a.foorescueputs:faila.barrescueputs:faila.zimrescueputs:faila.dibrescueputs:faila.gazrescueputs:fail测试输出failbarfailfailfail.发送测试[:foo,:bar,:zim,:dib,:gaz].each{|m|a.send(m)resc
很好奇，就使用rubyonrails自动化单元测试而言，你们正在做什么？您是否创建了一个脚本来在cron中运行rake作业并将结果邮寄给您？git中的预提交Hook？只是手动调用？我完全理解测试，但想知道在错误发生之前捕获错误的最佳实践是什么。让我们理所当然地认为测试本身是完美无缺的，并且可以正常工作。下一步是什么以确保他们在正确的时间将可能有害的结果传达给您？ 最佳答案 不确定您到底想听什么，但是有几个级别的自动代码库控制:在处理某项功能时，您可以使用类似autotest的内容获得关于哪些有效，哪些无效的即时反馈。要确保您的提
假设我做了一个模块如下:m=Module.newdoclassCendend三个问题:除了对m的引用之外，还有什么方法可以访问C和m中的其他内容？我可以在创建匿名模块后为其命名吗(就像我输入“module...”一样)？如何在使用完匿名模块后将其删除，使其定义的常量不再存在？ 最佳答案 三个答案:是的，使用ObjectSpace.此代码使c引用你的类(class)C不引用m:c=nilObjectSpace.each_object{|obj|c=objif(Class===objandobj.name=~/::C$/)}当然这取决于
我正在尝试使用ruby和Savon来使用网络服务。测试服务为http://www.webservicex.net/WS/WSDetails.aspx?WSID=9&CATID=2require'rubygems'require'savon'client=Savon::Client.new"http://www.webservicex.net/stockquote.asmx?WSDL"client.get_quotedo|soap|soap.body={:symbol=>"AAPL"}end返回SOAP异常。检查soap信封，在我看来soap请求没有正确的命名空间。任何人都可以建议我
我需要在客户计算机上运行Ruby应用程序。通常需要几天才能完成(复制大备份文件)。问题是如果启用sleep，它会中断应用程序。否则，计算机将持续运行数周，直到我下次访问为止。有什么方法可以防止执行期间休眠并让Windows在执行后休眠吗？欢迎任何疯狂的想法;-) 最佳答案 Here建议使用SetThreadExecutionStateWinAPI函数，使应用程序能够通知系统它正在使用中，从而防止系统在应用程序运行时进入休眠状态或关闭显示。像这样的东西:require'Win32API'ES_AWAYMODE_REQUIRED=0x0
关闭。这个问题是opinion-based.它目前不接受答案。想要改进这个问题？更新问题，以便editingthispost可以用事实和引用来回答它.关闭4年前。Improvethisquestion我想在固定时间创建一系列低音和高音调的哔哔声。例如:在150毫秒时发出高音调的蜂鸣声在151毫秒时发出低音调的蜂鸣声200毫秒时发出低音调的蜂鸣声250毫秒的高音调蜂鸣声有没有办法在Ruby或Python中做到这一点？我真的不在乎输出编码是什么(.wav、.mp3、.ogg等等)，但我确实想创建一个输出文件。
Rails2.3可以选择随时使用RouteSet#add_configuration_file添加更多路由。是否可以在Rails3项目中做同样的事情？ 最佳答案 在config/application.rb中:config.paths.config.routes在Rails3.2(也可能是Rails3.1)中，使用:config.paths["config/routes"] 关于ruby-on-rails-Rails3中的多个路由文件，我们在StackOverflow上找到一个类似的问题