WiSo's collector blog

Sometimes you would like to know if the tray of your CD/DVD/Bluray drive is open, closed and if a media is inserted. The following example shows how to archive that with C++. The return codes of the function GetDriveStatus() are:

-1 DRIVE_NOT_READY
 0 DRIVE_CLOSED_NO_MEDIA
 1 DRIVE_OPEN
 2 DRIVE_CLOSED_MEDIA_PRESENT

-1 DRIVE_NOT_READY

0 DRIVE_CLOSED_NO_MEDIA

1 DRIVE_OPEN

2 DRIVE_CLOSED_MEDIA_PRESENT

And now the example:

//** Defines taken from ntddscsi.h in MS Windows DDK CD
#define SCSI_IOCTL_DATA_OUT             0 //Give data to SCSI device (e.g. for writing)
#define SCSI_IOCTL_DATA_IN              1 //Get data from SCSI device (e.g. for reading)
#define SCSI_IOCTL_DATA_UNSPECIFIED     2 //No data (e.g. for ejecting)

#define MAX_SENSE_LEN 18 //Sense data max length

#define IOCTL_SCSI_PASS_THROUGH_DIRECT  0x4D014

typedef struct _SCSI_PASS_THROUGH_DIRECT {
    USHORT Length;
    UCHAR ScsiStatus;
    UCHAR PathId;
    UCHAR TargetId;
    UCHAR Lun;
    UCHAR CdbLength;
    UCHAR SenseInfoLength;
    UCHAR DataIn;
    ULONG DataTransferLength;
    ULONG TimeOutValue;
    PVOID DataBuffer;
    ULONG SenseInfoOffset;
    UCHAR Cdb[16];
}SCSI_PASS_THROUGH_DIRECT, *PSCSI_PASS_THROUGH_DIRECT;

typedef struct _SCSI_PASS_THROUGH_DIRECT_AND_SENSE_BUFFER {
    SCSI_PASS_THROUGH_DIRECT sptd;
    UCHAR SenseBuf[MAX_SENSE_LEN];
}T_SPDT_SBUF;

int GetDriveStatus(const CStdString &strPath, bool bStatusEx)
{
  HANDLE hDevice;               // handle to the drive to be examined
  int iResult;                  // results flag
  ULONG ulChanges=0;
  DWORD dwBytesReturned;
  T_SPDT_SBUF sptd_sb;  //SCSI Pass Through Direct variable.
  byte DataBuf[8];  //Buffer for holding data to/from drive.

  CLog::Log(LOGDEBUG, __FUNCTION__": Requesting status for drive %s.", strPath.c_str());

  hDevice = CreateFile( strPath.c_str(),                  // drive
                        0,                                // no access to the drive
                        FILE_SHARE_READ,                  // share mode
                        NULL,                             // default security attributes
                        OPEN_EXISTING,                    // disposition
                        FILE_ATTRIBUTE_READONLY,          // file attributes
                        NULL);

  if (hDevice == INVALID_HANDLE_VALUE)                    // cannot open the drive
  {
    CLog::Log(LOGERROR, __FUNCTION__": Failed to CreateFile for %s.", strPath.c_str());
    return -1;
  }

  CLog::Log(LOGDEBUG, __FUNCTION__": Requesting media status for drive %s.", strPath.c_str());
  iResult = DeviceIoControl((HANDLE) hDevice,             // handle to device
                             IOCTL_STORAGE_CHECK_VERIFY2, // dwIoControlCode
                             NULL,                        // lpInBuffer
                             0,                           // nInBufferSize
                             &ulChanges,                  // lpOutBuffer
                             sizeof(ULONG),               // nOutBufferSize
                             &dwBytesReturned ,           // number of bytes returned
                             NULL );                      // OVERLAPPED structure

  CloseHandle(hDevice);

  if(iResult == 1)
    return 2;

  // don't request the tray status as we often doesn't need it
  if(!bStatusEx)
    return 0;

  hDevice = CreateFile( strPath.c_str(),
                        GENERIC_READ | GENERIC_WRITE,
                        FILE_SHARE_READ | FILE_SHARE_WRITE,
                        NULL,
                        OPEN_EXISTING,
                        FILE_ATTRIBUTE_READONLY,
                        NULL);

  if (hDevice == INVALID_HANDLE_VALUE)
  {
    CLog::Log(LOGERROR, __FUNCTION__": Failed to CreateFile2 for %s.", strPath.c_str());
    return -1;
  }

  sptd_sb.sptd.Length=sizeof(SCSI_PASS_THROUGH_DIRECT);
  sptd_sb.sptd.PathId=0;
  sptd_sb.sptd.TargetId=0;
  sptd_sb.sptd.Lun=0;
  sptd_sb.sptd.CdbLength=10;
  sptd_sb.sptd.SenseInfoLength=MAX_SENSE_LEN;
  sptd_sb.sptd.DataIn=SCSI_IOCTL_DATA_IN;
  sptd_sb.sptd.DataTransferLength=sizeof(DataBuf);
  sptd_sb.sptd.TimeOutValue=2;
  sptd_sb.sptd.DataBuffer=(PVOID)&(DataBuf);
  sptd_sb.sptd.SenseInfoOffset=sizeof(SCSI_PASS_THROUGH_DIRECT);

  sptd_sb.sptd.Cdb[0]=0x4a;
  sptd_sb.sptd.Cdb[1]=1;
  sptd_sb.sptd.Cdb[2]=0;
  sptd_sb.sptd.Cdb[3]=0;
  sptd_sb.sptd.Cdb[4]=0x10;
  sptd_sb.sptd.Cdb[5]=0;
  sptd_sb.sptd.Cdb[6]=0;
  sptd_sb.sptd.Cdb[7]=0;
  sptd_sb.sptd.Cdb[8]=8;
  sptd_sb.sptd.Cdb[9]=0;
  sptd_sb.sptd.Cdb[10]=0;
  sptd_sb.sptd.Cdb[11]=0;
  sptd_sb.sptd.Cdb[12]=0;
  sptd_sb.sptd.Cdb[13]=0;
  sptd_sb.sptd.Cdb[14]=0;
  sptd_sb.sptd.Cdb[15]=0;

  ZeroMemory(DataBuf, 8);
  ZeroMemory(sptd_sb.SenseBuf, MAX_SENSE_LEN);

  //Send the command to drive
  CLog::Log(LOGDEBUG, __FUNCTION__": Requesting tray status for drive %s.", strPath.c_str());
  iResult = DeviceIoControl((HANDLE) hDevice,
                            IOCTL_SCSI_PASS_THROUGH_DIRECT,
                            (PVOID)&sptd_sb, (DWORD)sizeof(sptd_sb),
                            (PVOID)&sptd_sb, (DWORD)sizeof(sptd_sb),
                            &dwBytesReturned,
                            NULL);

  CloseHandle(hDevice);

  if(iResult)
  {

    if(DataBuf[5] == 0) // tray close
      return 0;
    else if(DataBuf[5] == 1) // tray open
      return 1;
    else
      return 2; // tray closed, media present
  }
  CLog::Log(LOGERROR, __FUNCTION__": Could not determine tray status %d", GetLastError());
  return -1;
}

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//** Defines taken from ntddscsi.h in MS Windows DDK CD

#define SCSI_IOCTL_DATA_OUT 0 //Give data to SCSI device (e.g. for writing)

#define SCSI_IOCTL_DATA_IN 1 //Get data from SCSI device (e.g. for reading)

#define SCSI_IOCTL_DATA_UNSPECIFIED 2 //No data (e.g. for ejecting)

#define MAX_SENSE_LEN 18 //Sense data max length

#define IOCTL_SCSI_PASS_THROUGH_DIRECT 0x4D014

typedef struct _SCSI_PASS_THROUGH_DIRECT {

USHORT Length;

UCHAR ScsiStatus;

UCHAR PathId;

UCHAR TargetId;

UCHAR Lun;

UCHAR CdbLength;

UCHAR SenseInfoLength;

UCHAR DataIn;

ULONG DataTransferLength;

ULONG TimeOutValue;

PVOID DataBuffer;

ULONG SenseInfoOffset;

UCHAR Cdb[16];

}SCSI_PASS_THROUGH_DIRECT, *PSCSI_PASS_THROUGH_DIRECT;

typedef struct _SCSI_PASS_THROUGH_DIRECT_AND_SENSE_BUFFER {

SCSI_PASS_THROUGH_DIRECT sptd;

UCHAR SenseBuf[MAX_SENSE_LEN];

}T_SPDT_SBUF;

int GetDriveStatus(const CStdString &strPath, bool bStatusEx)

{

HANDLE hDevice; // handle to the drive to be examined

int iResult; // results flag

ULONG ulChanges=0;

DWORD dwBytesReturned;

T_SPDT_SBUF sptd_sb; //SCSI Pass Through Direct variable.

byte DataBuf[8]; //Buffer for holding data to/from drive.

CLog::Log(LOGDEBUG, __FUNCTION__": Requesting status for drive %s.", strPath.c_str());

hDevice = CreateFile( strPath.c_str(), // drive

0, // no access to the drive

FILE_SHARE_READ, // share mode

NULL, // default security attributes

OPEN_EXISTING, // disposition

FILE_ATTRIBUTE_READONLY, // file attributes

NULL);

if (hDevice == INVALID_HANDLE_VALUE) // cannot open the drive

{

CLog::Log(LOGERROR, __FUNCTION__": Failed to CreateFile for %s.", strPath.c_str());

return -1;

}

CLog::Log(LOGDEBUG, __FUNCTION__": Requesting media status for drive %s.", strPath.c_str());

iResult = DeviceIoControl((HANDLE) hDevice, // handle to device

IOCTL_STORAGE_CHECK_VERIFY2, // dwIoControlCode

NULL, // lpInBuffer

0, // nInBufferSize

&ulChanges, // lpOutBuffer

sizeof(ULONG), // nOutBufferSize

&dwBytesReturned , // number of bytes returned

NULL ); // OVERLAPPED structure

CloseHandle(hDevice);

if(iResult == 1)

return 2;

// don't request the tray status as we often doesn't need it

if(!bStatusEx)

return 0;

hDevice = CreateFile( strPath.c_str(),

GENERIC_READ | GENERIC_WRITE,

FILE_SHARE_READ | FILE_SHARE_WRITE,

NULL,

OPEN_EXISTING,

FILE_ATTRIBUTE_READONLY,

NULL);

if (hDevice == INVALID_HANDLE_VALUE)

{

CLog::Log(LOGERROR, __FUNCTION__": Failed to CreateFile2 for %s.", strPath.c_str());

return -1;

}

sptd_sb.sptd.Length=sizeof(SCSI_PASS_THROUGH_DIRECT);

sptd_sb.sptd.PathId=0;

sptd_sb.sptd.TargetId=0;

sptd_sb.sptd.Lun=0;

sptd_sb.sptd.CdbLength=10;

sptd_sb.sptd.SenseInfoLength=MAX_SENSE_LEN;

sptd_sb.sptd.DataIn=SCSI_IOCTL_DATA_IN;

sptd_sb.sptd.DataTransferLength=sizeof(DataBuf);

sptd_sb.sptd.TimeOutValue=2;

sptd_sb.sptd.DataBuffer=(PVOID)&(DataBuf);

sptd_sb.sptd.SenseInfoOffset=sizeof(SCSI_PASS_THROUGH_DIRECT);

sptd_sb.sptd.Cdb[0]=0x4a;

sptd_sb.sptd.Cdb[1]=1;

sptd_sb.sptd.Cdb[2]=0;

sptd_sb.sptd.Cdb[3]=0;

sptd_sb.sptd.Cdb[4]=0x10;

sptd_sb.sptd.Cdb[5]=0;

sptd_sb.sptd.Cdb[6]=0;

sptd_sb.sptd.Cdb[7]=0;

sptd_sb.sptd.Cdb[8]=8;

sptd_sb.sptd.Cdb[9]=0;

sptd_sb.sptd.Cdb[10]=0;

sptd_sb.sptd.Cdb[11]=0;

sptd_sb.sptd.Cdb[12]=0;

sptd_sb.sptd.Cdb[13]=0;

sptd_sb.sptd.Cdb[14]=0;

sptd_sb.sptd.Cdb[15]=0;

ZeroMemory(DataBuf, 8);

ZeroMemory(sptd_sb.SenseBuf, MAX_SENSE_LEN);

//Send the command to drive

CLog::Log(LOGDEBUG, __FUNCTION__": Requesting tray status for drive %s.", strPath.c_str());

iResult = DeviceIoControl((HANDLE) hDevice,

IOCTL_SCSI_PASS_THROUGH_DIRECT,

(PVOID)&sptd_sb, (DWORD)sizeof(sptd_sb),

&dwBytesReturned,

NULL);

CloseHandle(hDevice);

if(iResult)

{

if(DataBuf[5] == 0) // tray close

return 0;

else if(DataBuf[5] == 1) // tray open

return 1;

else

return 2; // tray closed, media present

}

CLog::Log(LOGERROR, __FUNCTION__": Could not determine tray status %d", GetLastError());

return -1;

}

We first check in line 57 with IOCTL_STORAGE_CHECK_VERIFY2 if we have a media in our drive. If this returns 1 we have a medium loaded and we can early return and save another call to DeviceIoControl().
In line 123 we finally request the tray status with a IOCTL_SCSI_PASS_THROUGH_DIRECT call.

I recently did my first steps with cmake and it wasn’t easy as there’re not much sources on how to use it with visual studio. After some try and error I got some things done which I wanted to document here.

Variables

CMAKE_SOURCE_DIR path to CMakeLists.txt
CMAKE_BINARY_DIR path to the compiled target file

1 2	CMAKE_SOURCE_DIR path to CMakeLists.txt CMAKE_BINARY_DIR path to the compiled target file

Build Debug or Release dll’s

cmake offers different ways for building release and debug configs with visual studio depending on the generator.

nmake makefiles:

cmake -G "NMake Makefiles" -DBUILD_SHARED_LIBS=1 -DCMAKE_BUILD_TYPE=Release ..
cmake --build .

1 2	cmake -G "NMake Makefiles" -DBUILD_SHARED_LIBS=1 -DCMAKE_BUILD_TYPE=Release .. cmake --build .

Visual Studio:

cmake -G "Visual Studio 10"..
cmake --build . --config Release

1 2	cmake -G "Visual Studio 10".. cmake --build . --config Release

Add preprocessor definitions

ADD_DEFINITIONS(-DTARGET_WINDOWS -Dwhatever)

1	ADD_DEFINITIONS(-DTARGET_WINDOWS -Dwhatever)

Download a file and check the status

Downloads the file BINDING_FILE from http://ws0.org/xbmc/win32/ and puts it into the build directory.

file(DOWNLOAD http://ws0.org/xbmc/win32/${BINDING_FILE} 
  ${CMAKE_BINARY_DIR}/${BINDING_FILE} STATUS STATUSLIST SHOW_PROGRESS)
LIST(GET STATUSLIST 0 VALUE)
IF(${VALUE} STRGREATER "0")
  LIST(GET STATUSLIST 1 VALUE)
  message (STATUS "failed to download XBMC bindings: " ${VALUE})
ENDIF(${VALUE} STRGREATER "0")

file(DOWNLOAD http://ws0.org/xbmc/win32/${BINDING_FILE}

${CMAKE_BINARY_DIR}/${BINDING_FILE} STATUS STATUSLIST SHOW_PROGRESS)

LIST(GET STATUSLIST 0 VALUE)

IF(${VALUE} STRGREATER "0")

LIST(GET STATUSLIST 1 VALUE)

message (STATUS "failed to download XBMC bindings: " ${VALUE})

ENDIF(${VALUE} STRGREATER "0")

Unpack zip file

execute_process executes the command during compile time and not on configure.

execute_process(
  COMMAND ${CMAKE_COMMAND} -E tar xzf ${CMAKE_BINARY_DIR}/${BINDING_FILE}
)

execute_process(

COMMAND ${CMAKE_COMMAND} -E tar xzf ${CMAKE_BINARY_DIR}/${BINDING_FILE}

)

Create an archive with cpack

INSTALL(DIRECTORY visualization.waveform DESTINATION ./)
INSTALL(PROGRAMS ${CMAKE_BINARY_DIR}/waveform.dll DESTINATION visualization.waveform)
SET(CPACK_GENERATOR "ZIP")
SET(CPACK_INCLUDE_TOPLEVEL_DIRECTORY OFF)
#SET(CPACK_PACKAGE_FILE_NAME "waveform.test") -> would give the package a different name than default
INCLUDE(CPack)

INSTALL(DIRECTORY visualization.waveform DESTINATION ./)

INSTALL(PROGRAMS ${CMAKE_BINARY_DIR}/waveform.dll DESTINATION visualization.waveform)

SET(CPACK_GENERATOR "ZIP")

SET(CPACK_INCLUDE_TOPLEVEL_DIRECTORY OFF)

#SET(CPACK_PACKAGE_FILE_NAME "waveform.test") -> would give the package a different name than default

INCLUDE(CPack)

Adds a new target ‘package’ which could be called with ‘nmake package’ or ‘cmake –build . –target=PACKAGE.’
Inside the zip is the directory visualization.waveform with the contents
of the directory visualization.waveform plus the waveform.dll file.

Use external Visual Studio project file

INCLUDE_EXTERNAL_MSPROJECT(milkdrop ${CMAKE_SOURCE_DIR}/src/Plugin.sln)

1	INCLUDE_EXTERNAL_MSPROJECT(milkdrop ${CMAKE_SOURCE_DIR}/src/Plugin.sln)

Generates a target ‘milkdrop’ for use like add dependencies. Visual Studio generators only.
INCLUDE_DIRECTORIES has no affect on those targets.

Set Visual Studio compile parameters

SET (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /Oi /Ob1 /Zi /arch:SSE")

1	SET (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /Oi /Ob1 /Zi /arch:SSE")

Set compile language per source

SET_SOURCE_FILES_PROPERTIES( ${EVALLIBSRC} PROPERTIES LANGUAGE C )

1	SET_SOURCE_FILES_PROPERTIES( ${EVALLIBSRC} PROPERTIES LANGUAGE C )

Sets the compiler language to C for all sources in ${EVALLIBSRC}

Add additionale include and linker directories

INCLUDE_DIRECTORIES(${XBMC_INCLUDE_DIR} $ENV{DXSDK_DIR}Include)
LINK_DIRECTORIES($ENV{DXSDK_DIR}Lib/x86)

1 2	INCLUDE_DIRECTORIES(${XBMC_INCLUDE_DIR} $ENV{DXSDK_DIR}Include) LINK_DIRECTORIES($ENV{DXSDK_DIR}Lib/x86)

things I would like to remember

windows: How to get the tray status of an optical drive

cmake and visual studio

Variables

Build Debug or Release dll’s

Add preprocessor definitions

Download a file and check the status

Unpack zip file

Create an archive with cpack

Use external Visual Studio project file

Set Visual Studio compile parameters

Set compile language per source

Add additionale include and linker directories

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