• NAME
• SUPPORTED PLATFORMS
• SYNOPSIS
• DESCRIPTION
• Exports
• BUGS
• AUTHOR
• SEE ALSO

NAME

Win32API::File - Low-level access to Win32 system API calls for files/dirs.

SUPPORTED PLATFORMS

• Windows

SYNOPSIS

  use Win32API::File 0.08 qw( :ALL );

  MoveFile( $Source, $Destination )
    or  die "Can't move $Source to $Destination: ",fileLastError(),"\n";
  MoveFileEx( $Source, $Destination, MOVEFILE_REPLACE_EXISTING() )
    or  die "Can't move $Source to $Destination: ",fileLastError(),"\n";
  [...]

DESCRIPTION

This provides fairly low-level access to the Win32 System API calls dealing with files and directories.

To pass in NULL as the pointer to an optional buffer, pass in an empty list reference, [].

Beyond raw access to the API calls and related constants, this module handles smart buffer allocation and translation of return codes.

All functions, unless otherwise noted, return a true value for success and a false value for failure and set $^E on failure.

Exports

Nothing is exported by default. The following tags can be used to have large sets of symbols exported: ":Func", ":FuncA", ":FuncW", ":Misc", ":DDD_", ":DRIVE_", ":FILE_", ":FILE_ATTRIBUTE_", ":FILE_FLAG_", ":FILE_SHARE_", ":FILE_TYPE_", ":FS_", ":HANDLE_FLAG_", ":IOCTL_STORAGE_", ":IOCTL_DISK_", ":GENERIC_", ":MEDIA_TYPE", ":MOVEFILE_", ":SECURITY_", ":SEM_", and ":PARTITION_".

":Func"

The basic function names: attrLetsToBits, createFile, fileConstant, fileLastError, getLogicalDrives, CloseHandle, CopyFile, CreateFile, DefineDosDevice, DeleteFile, DeviceIoControl, FdGetOsFHandle, GetDriveType, GetFileType, GetHandleInformation, GetLogicalDrives, GetLogicalDriveStrings, GetOsFHandle, GetVolumeInformation, IsRecognizedPartition, IsContainerPartition, MoveFile, MoveFileEx, OsFHandleOpen, OsFHandleOpenFd, QueryDosDevice, ReadFile, SetErrorMode, SetFilePointer, SetHandleInformation, and WriteFile.

attrLetsToBits

$uBits= attrLetsToBits( $sAttributeLetters )

Converts a string of file attribute letters into an unsigned value with the corresponding bits set. $sAttributeLetters should contain zero or more letters from "achorst":

"a"

FILE_ATTRIBUTE_ARCHIVE

"c"

FILE_ATTRIBUTE_COMPRESSED

"h"

FILE_ATTRIBUTE_HIDDEN

"o"

FILE_ATTRIBUTE_OFFLINE

"r"

FILE_ATTRIBUTE_READONLY

"s"

FILE_ATTRIBUTE_SYSTEM

"t"

FILE_ATTRIBUTE_TEMPORARY

createFile

$hObject= createFile( $sPath )

$hObject= createFile( $sPath, $rvhvOptions )

$hObject= createFile( $sPath, $svAccess )

$hObject= createFile( $sPath, $svAccess, $rvhvOptions )

$hObject= createFile( $sPath, $svAccess, $svShare )

$hObject= createFile( $sPath, $svAccess, $svShare, $rvhvOptions )

This is a Perl-friendly wrapper around CreateFile.

On failure, $hObject gets set to a false value and regLastError() and $^E are set to the reason for the failure. Otherwise, $hObject gets set to a Win32 native file handle which is alwasy a true value [returns "0 but true" in the impossible(?) case of the handle having a value of 0].

$sPath is the path to the file [or device, etc.] to be opened. See CreateFile for more information on possible special values for $sPath.

$svAccess can be a number containing the bit mask representing the specific type(s) of access to the file that you desire. See the $uAccess parameter to CreateFile for more information on these values.

More likely, $svAccess is a string describing the generic type of access you desire and possibly the file creation options to use. In this case, $svAccess should contain zero or more characters from "qrw" [access desired], zero or one character each from "ktn" and "ce", and optional white space. These letters stand for, respectively, ``Query access'', ``Read access'', ``Write access'', ``Keep if exists'', ``Truncate if exists'', ``New file only'', ``Create if none'', and ``Existing file only''. Case is ignored.

You can pass in "?" for $svAccess to have an error message displayed summarizing its possible values. This is very handy when doing on-the-fly programming using the Perl debugger:

    Win32API::File::createFile:  $svAccess can use the following:
        One or more of the following:
            q -- Query access (same as 0)
            r -- Read access (GENERIC_READ)
            w -- Write access (GENERIC_WRITE)
        At most one of the following:
            k -- Keep if exists
            t -- Truncate if exists
            n -- New file only (fail if file already exists)
        At most one of the following:
            c -- Create if doesn't exist
            e -- Existing file only (fail if doesn't exist)
      ''   is the same as 'q  k e'
      'r'  is the same as 'r  k e'
      'w'  is the same as 'w  t c'
      'rw' is the same as 'rw k c'
      'rt' or 'rn' implies 'c'.
      Or $access can be numeric.

$svAccess is designed to be ``do what I mean'', so you can skip the rest of its explanation unless you are interested in the complex details. Note that, if you want write access to a device, you need to specify "k" [and perhaps "e", as in "w ke" or "rw ke"] since Win32 suggests OPEN_EXISTING be used when opening a device.

"q"

Stands for ``Query access''. This is really a no-op since you always have query access when you open a file. You can specify "q" to document that you plan to query the file [or device, etc.]. This is especially helpful when you don't want read nor write access since something like "q" or "q ke" may be easier to understand than just "" or "ke".

"r"

Stands for ``Read access''. Sets the GENERIC_READ bit(s) in the $uAccess that is passed to CreateFile. This is the default access if the $svAccess parameter is missing [or if it is undef and $rvhvOptions doesn't specify an "Access" option].

"w"

Stands for ``Write access''. Sets the GENERIC_WRITE bit(s) in the $uAccess that is passed to CreateFile.

"k"

Stands for ``Keep if exists''. If the requested file exists, then it is opened. This is the default unless GENERIC_WRITE access has been requested but GENERIC_READ access has not been requested. Contrast with "t" and "n".

"t"

Stands for ``Truncate if exists''. If the requested file exists, then it is truncated to zero length and then opened. This is the default if GENERIC_WRITE access has been requested and GENERIC_READ access has not been requested. Contrast with "k" and "n".

"n"

Stands for ``New file only''. If the requested file exists, then it is not opened and the createFile call fails. Contrast with "k" and "t". Can't be used with "e".

"c"

Stands for ``Create if none''. If the requested file does not exist, then it is created and then opened. This is the default if GENERIC_WRITE access has been requested or if "t" or "n" was specified. Contrast with "e".

"e"

Stands for ``Existing file only''. If the requested file does not exist, then nothing is opened and the createFile call fails. This is the default unless GENERIC_WRITE access has been requested or "t" or "n" was specified. Contrast with "c". Can't be used with "n".

The characters from "ktn" and "ce" are combined to determine the what value for $uCreate to pass to CreateFile [unless overridden by $rvhvOptions]:

"kc"

OPEN_ALWAYS

"ke"

OPEN_EXISTING

"tc"

TRUNCATE_EXISTING

"te"

CREATE_ALWAYS

"nc"

CREATE_NEW

"ne"

Illegal.

$svShare controls how the file is shared, that is, whether other processes can have read, write, and/or delete access to the file while we have it opened. $svShare will usually be a string containing zero or more characters from "rwd" but can also be a numeric bit mask.

"r" sets the FILE_SHARE_READ bit which allows other processes to have read access to the file. "w" sets the FILE_SHARE_WRITE bit which allows other processes to have write access to the file. "d" sets the FILE_SHARE_DELETE bit which allows other processes to have delete access to the file [ignored under Windows 95].

The default for $svShare is "rw" which provides the same sharing as using regular perl open().

If another process currently has read, write, and/or delete access to the file and you don't allow that level of sharing, then your call to createFile will fail. If you requested read, write, and/or delete access and another process already has the file open but doesn't allow that level of sharing, then your call to createFile will fail. Once you have the file open, if another process tries to open it with read, write, and/or delete access and you don't allow that level of sharing, then that process won't be allowed to open the file.

$rvhvOptions is a reference to a hash where any keys must be from the list qw( Access Create Share Attributes Flags Security Model ). The meaning of the value depends on the key name, as described below. Any option values in $rvhvOptions override the settings from $svAccess and $svShare if they conflict.

Flags => $uFlags

$uFlags is an unsigned value having any of the FILE_FLAG_* or FILE_ATTRIBUTE_* bits set. Any FILE_ATTRIBUTE_* bits set via the Attributes option are logically ored with these bits. Defaults to 0.

If opening the client side of a named pipe, then you can also specify SECURITY_SQOS_PRESENT along with one of the other SECURITY_* constants to specify the security quality of service to be used.

Attributes => $sAttributes

A string of zero or more characters from "achorst" [see attrLetsToBits for more information] which are converted to FILE_ATTRIBUTE_* bits to be set in the $uFlags argument passed to CreateFile.

Security => $pSecurityAttributes

$pSecurityAttributes should contain a SECURITY_ATTRIBUTES structure packed into a string or [] [the default].

Model => $hModelFile

$hModelFile should contain a handle opened with GENERIC_READ access to a model file from which file attributes and extended attributes are to be copied. Or $hModelFile can be 0 [the default].

Access => $sAccess

Access => $uAccess

$sAccess should be a string of zero or more characters from "qrw" specifying the type of access desired: ``query'' or 0, ``read'' or GENERIC_READ [the default], or ``write'' or GENERIC_WRITE.

$uAccess should be an unsigned value containing bits set to indicate the type of access desired. GENERIC_READ is the default.

Create => $sCreate

Create => $uCreate

$sCreate should be a string constaing zero or one character from "ktn" and zero or one character from "ce". These stand for ``Keep if exists'', ``Truncate if exists'', ``New file only'', ``Create if none'', and ``Existing file only''. These are translated into a $uCreate value.

$uCreate should be one of OPEN_ALWAYS, OPEN_EXISTING, TRUNCATE_EXISTING, CREATE_ALWAYS, or CREATE_NEW.

Share => $sShare

Share => $uShare

$sShare should be a string with zero or more characters from "rwd" that is translated into a $uShare value. "rw" is the default.

$uShare should be an unsigned value having zero or more of the following bits set: FILE_SHARE_READ, FILE_SHARE_WRITE, and FILE_SHARE_DELETE. FILE_SHARE_READ|FILE_SHARE_WRITE is the default.

Examples:

    $hFlop= createFile( "//./A:", "r", "r" )
      or  die "Can't prevent others from writing to floppy: $^E\n";
    $hDisk= createFile( "//./C:", "rw ke", "" )
      or  die "Can't get exclusive access to C: $^E\n";
    $hDisk= createFile( $sFilePath, "ke",
      { Access=>FILE_READ_ATTRIBUTES } )
      or  die "Can't read attributes of $sFilePath: $^E\n";
    $hTemp= createFile( "$ENV{Temp}/temp.$$", "wn", "",
      { Attributes=>"hst", Flags=>FILE_FLAG_DELETE_ON_CLOSE() } )
      or  die "Can't create temporary file, temp.$$: $^E\n";

getLogicalDrives

@roots= getLogicalDrives()

Returns the paths to the root directories of all logical drives currently defined. This includes all types of drive lettters, such as floppies, CD-ROMs, hard disks, and network shares. A typical return value on a poorly equipped computer would be ("A:\\","C:\\").

CloseHandle

CloseHandle( $hObject )

Closes a Win32 native handle, such as one opened via CreateFile. Like most routines, returns a true value if successful and a false value [and sets $^E and regLastError()] on failure.

CopyFile

CopyFile( $sOldFileName, $sNewFileName, $bFailIfExists )

$sOldFileName is the path to the file to be copied. $sNewFileName is the path to where the file should be copied. Note that you can ¬ just specify a path to a directory in $sNewFileName to copy the file to that directory using the same file name.

If $bFailIfExists is true and $sNewFileName is the path to a file that already exists, then CopyFile will fail. If $bFailIfExists is falsea, then the copy of the $sOldFileNmae file will overwrite the $sNewFileName file if it already exists.

Like most routines, returns a true value if successful and a false value [and sets $^E and regLastError()] on failure.

CreateFile

$hObject= CreateFile( $sPath, $uAccess, $uShare, $pSecAttr, $uCreate, $uFlags, $hModel )

On failure, $hObject gets set to a false value and $^E and fileLastError() are set to the reason for the failure. Otherwise, $hObject gets set to a Win32 native file handle which is always a true value [returns "0 but true" in the impossible(?) case of the handle having a value of 0].

$sPath is the path to the file [or device, etc.] to be opened.

$sPath can use "/" or "\\" as path delimiters and can even mix the two. We will usually only use "/" in our examples since using "\\" is usually harder to read.

Under Windows NT, $sPath can start with "//?/" to allow the use of paths longer than MAX_PATH [for UNC paths, replace the leading "//" with "//?/UNC/", as in "//?/UNC/Server/Share/Dir/File.Ext"].

$sPath can start with "//./" to indicate that the rest of the path is the name of a ``DOS device.'' You can use QueryDosDevice to list all current DOS devices and can add or delete them with DefineDosDevice. If you get the source-code distribution of this module from CPAN, then it includes an example script, ex/ListDevs.plx that will list all current DOS devices and their ``native'' definition. Again, note that this doesn't work under Win95 nor Win98.

The most common such DOS devices include:

"//./PhysicalDrive0"

Your entire first hard disk. Doesn't work under Windows 95. This allows you to read or write raw sectors of your hard disk and to use DeviceIoControl to perform miscellaneous queries and operations to the hard disk. Writing raw sectors and certain other operations can seriously damage your files or the function of your computer.

Locking this for exclusive access [by specifying 0 for $uShare] doesn't prevent access to the partitions on the disk nor their file systems. So other processes can still access any raw sectors within a partition and can use the file system on the disk as usual.

"//./C:"

Your C: partition. Doesn't work under Windows 95. This allows you to read or write raw sectors of that partition and to use DeviceIoControl to perform miscellaneous queries and operations to the partition. Writing raw sectors and certain other operations can seriously damage your files or the function of your computer.

Locking this for exclusive access doesn't prevent access to the physical drive that the partition is on so other processes can still access the raw sectors that way. Locking this for exclusive access &does; prevent other processes from opening the same raw partition and &does; prevent access to the file system on it. It even prevents the current process from accessing the file system on that partition.

"//./A:"

The raw floppy disk. Doesn't work under Windows 95. This allows you to read or write raw sectors of the floppy disk and to use DeviceIoControl to perform miscellaneous queries and operations to the floopy disk or drive.

Locking this for exclusive access prevents all access to the floppy.

"//./PIPE/PipeName"

A named pipe, created via CreateNamedPipe.

$uAccess is an unsigned value with bits set indicating the type of access desired. Usually either 0 [``query'' access], GENERIC_READ, GENERIC_WRITE, GENERIC_READ|GENERIC_WRITE, or GENERIC_ALL. More specific types of access can be specified, such as FILE_APPEND_DATA or FILE_READ_EA.

$uShare controls how the file is shared, that is, whether other processes can have read, write, and/or delete access to the file while we have it opened. $uShare is an unsigned value with zero or more of these bits set: FILE_SHARE_READ, FILE_SHARE_WRITE, and FILE_SHARE_DELETE.

If another process currently has read, write, and/or delete access to the file and you don't allow that level of sharing, then your call to CreateFile will fail. If you requested read, write, and/or delete access and another process already has the file open but doesn't allow that level of sharing, thenn your call to createFile will fail. Once you have the file open, if another process tries to open it with read, write, and/or delete access and you don't allow that level of sharing, then that process won't be allowed to open the file.

$pSecAttr should either be [] [for NULL] or a SECURITY_ATTRIBUTES data structure packed into a string. For example, if $pSecDesc contains a SECURITY_DESCRIPTOR structure packed into a string, perhaps via:

    RegGetKeySecurity( $key, 4, $pSecDesc, 1024 );

then you can set $pSecAttr via:

    $pSecAttr= pack( "L P i", 12, $pSecDesc, $bInheritHandle );

$uCreate is one of the following values: OPEN_ALWAYS, OPEN_EXISTING, TRUNCATE_EXISTING, CREATE_ALWAYS, and CREATE_NEW.

$uFlags is an unsigned value with zero or more bits set indicating attributes to associate with the file [FILE_ATTRIBUTE_* values] or special options [FILE_FLAG_* values].

If opening the client side of a named pipe, then you can also set $uFlags to include SECURITY_SQOS_PRESENT along with one of the other SECURITY_* constants to specify the security quality of service to be used.

$hModel is 0 [or [], both of which mean NULL] or a Win32 native handle opened with GENERIC_READ access to a model file from which file attributes and extended attributes are to be copied if a new file gets created.

Examples:

    $hFlop= CreateFile( "//./A:", GENERIC_READ(),
      FILE_SHARE_READ(), [], OPEN_EXISTING(), 0, [] )
      or  die "Can't prevent others from writing to floppy: $^E\n";
    $hDisk= createFile( $sFilePath, FILE_READ_ATTRIBUTES(),
      FILE_SHARE_READ()|FILE_SHARE_WRITE(), [], OPEN_EXISTING(), 0, [] )
      or  die "Can't read attributes of $sFilePath: $^E\n";
    $hTemp= createFile( "$ENV{Temp}/temp.$$", GENERIC_WRITE(), 0,
      CREATE_NEW(), FILE_FLAG_DELETE_ON_CLOSE()|attrLetsToBits("hst"), [] )
      or  die "Can't create temporary file, temp.$$: $^E\n";

DefineDosDevice

DefineDosDevice( $uFlags, $sDosDeviceName, $sTargetPath )

Defines a new DOS device, overrides the current definition of a DOS device, or deletes a definition of a DOS device. Like most routines, returns a true value if successful and a false value [and sets $^E and regLastError()] on failure.

$sDosDeviceName is the name of a DOS device for which we'd like to add or delete a definition.

$uFlags is an unsigned value with zero or more of the following bits set:

DDD_RAW_TARGET_PATH

Indicates that $sTargetPath will be a raw Windows NT object name. This usually means that $sTargetPath starts with "\\Device\\". Note that you cannot use "/" in place of "\\" in raw target path names.

DDD_REMOVE_DEFINITION

Requests that a definition be deleted. If $sTargetPath is [] [for NULL], then the most recently added definition for $sDosDeviceName is removed. Otherwise the most recently added definition matching $sTargetPath is removed.

If the last definition is removed, then the DOS device name is also deleted.

DDD_EXACT_MATCH_ON_REMOVE

When deleting a definition, this bit causes each $sTargetPath to be compared to the full-length definition when searching for the most recently added match. If this bit is not set, then $sTargetPath only needs to match a prefix of the definition.

$sTargetPath is the DOS device's specific definition that you wish to add or delete. For DDD_RAW_TARGET_PATH, these usually start with "\\Device\\". If the DDD_RAW_TARGET_PATH bit is not set, then $sTargetPath is just an ordinary path to some file or directory, providing the functionality of the subst command.

DeleteFile

DeleteFile( $sFileName )

Deletes the named file. Compared to Perl's unlink, DeleteFile has the advantage of not deleting read-only files. For &some; versions of Perl, unlink silently calls chmod whether it needs to or not before deleting the file so that files that you have protected by marking them as read-only are not always protected from Perl's unlink.

Like most routines, returns a true value if successful and a false value [and sets $^E and regLastError()] on failure.

DeviceIoControl

DeviceIoControl( $hDevice, $uIoControlCode, $pInBuf, $lInBuf, $opOutBuf, $lOutBuf, $olRetBytes, $pOverlapped )

Requests a special operation on an I/O [input/output] device, such as ejecting a tape or formatting a disk. Like most routines, returns a true value if successful and a false value [and sets $^E and regLastError()] on failure.

$hDevice is a Win32 native file handle to a device [return value from CreateFile].

$uIoControlCode is an unsigned value [a IOCTL_* constant] indicating the type query or other operation to be performed.

$pInBuf is [] [for NULL] or a data structure packed into a string. The type of data structure depends on the $uIoControlCode value. $lInBuf is 0 or the length of the structure in $pInBuf. If $pInBuf is not [] and $lInBuf is 0, then $lInBuf will automatically be set to length($pInBuf) for you.

$opOutBuf is [] [for NULL] or will be set to contain a returned data structure packed into a string. $lOutBuf indicates how much space to allocate in $opOutBuf for DeviceIoControl to store the data structure. If $lOutBuf is a number and $opOutBuf already has a buffer allocated for it that is larger than $lOutBuf bytes, then this larger buffer size will be passed to DeviceIoControl. However, you can force a specific buffer size to be passed to DeviceIoControl by prepending a "=" to the front of $lOutBuf.

$olRetBytes is [] or is a scalar to receive the number of bytes written to $opOutBuf. Even when $olRetBytes is [], a valid pointer to a DWORD [and not NULL] is passed to DeviceIoControl. In this case, [] just means that you don't care about the value that might be written to $olRetBytes, which is usually the case since you can usually use length($opOutBuf) instead.

$pOverlapped is [] or is a OVERLAPPED structure packed into a string. This is only useful if $hDevice was opened with the FILE_FLAG_OVERLAPPED flag set.

FdGetOsFHandle

$hNativeHandle= FdGetOsFHandle( $ivFd )

FdGetOsFHandle simply calls _get_osfhandle(). It was renamed to better fit in with the rest the function names of this module, in particular to distinguish it from GetOsFHandle. It takes an integer file descriptor [as from Perl's fileno] and returns the Win32 native file handle associated with that file descriptor or INVALID_HANDLE_VALUE if $ivFd is not an open file descriptor.

When you call Perl's open to set a Perl file handle [like STDOUT], Perl calls C's fopen to set a stdio FILE *. C's fopen calls something like Unix's open, that is, Win32's _sopen, to get an integer file descriptor [where 0 is for STDIN, 1 for STDOUT, etc.]. Win32's _sopen calls CreateFile to set a HANDLE, a Win32 native file handle. So every Perl file handle [like STDOUT] has an integer file descriptor associated with it that you can get via fileno. And, under Win32, every file descriptor has a Win32 native file handle associated with it. FdGetOsFHandle lets you get access to that.

$hNativeHandle is set to INVALID_HANDLE_VALUE [and lastFileError() and $^E are set] if FdGetOsFHandle fails. See also GetOsFHandle which provides a friendlier interface.

fileConstant

$value= fileConstant( $sConstantName )

Fetch the value of a constant. Returns undef if $sConstantName is not the name of a constant supported by this module. Never sets $! nor $^E.

This function is rarely used since you will usually get the value of a constant by having that constant imported into your package by listing the constant name in the use Win32API::File statement and then simply using the constant name in your code [perhaps followed by ()]. This function is useful for verifying constant names not in Perl code, for example, after prompting a user to type in a constant name.

fileLastError

$svError= fileLastError();

fileLastError( $uError );

Returns the last error encountered by a routine from this module. It is just like $^E except it isn't changed by anything except routines from this module. Ideally you could just use $^E, but current versions of Perl often overwrite $^E before you get a chance to check it and really old versions of Perl don't really support $^E under Win32.

Just like $^E, in a numeric context fileLastError() returns the numeric error value while in a string context it returns a text description of the error [actually it returns a Perl scalar that contains both values so $x= fileLastError() causes $x to give different values in string vs. numeric contexts]. On old versions of Perl where $^E isn't tied to GetLastError(), fileLastError simply returns the number of the error and you'll need to use <Win32::FormatMessage> to get the error string.

The last form sets the error returned by future calls to fileLastError() and should not be used often. $uError must be a numeric error code. Also returns the dual-valued version of $uError.

GetDriveType

$uDriveType= GetDriveType( $sRootPath )

Takes a string giving the path to the root directory of a file system [called a ``drive'' because every file system is assigned a ``drive letter''] and returns an unsigned value indicating the type of drive the file system is on. The return value should be one of:

DRIVE_UNKNOWN

None of the following.

DRIVE_NO_ROOT_DIR

A ``drive'' that does not have a file system. This can be a drive letter that hasn't been defined or a drive letter assigned to a partition that hasn't been formatted yet.

DRIVE_REMOVABLE

A floppy diskette drive or other removable media drive, but not a CD-ROM drive.

DRIVE_FIXED

An ordinary hard disk partition.

DRIVE_REMOTE

A network share.

DRIVE_CDROM

A CD-ROM drive.

DRIVE_RAMDISK

A ``ram disk'' or memory-resident virtual file system used for high-speed access to small amounts of temporary file space.

GetFileType

$uFileType= GetFileType( $hFile )

Takes a Win32 native file handle and returns a FILE_TYPE_* constant indicating the type of the file opened on that handle:

FILE_TYPE_UNKNOWN

None of the below. Often a special device.

FILE_TYPE_DISK

An ordinary disk file.

FILE_TYPE_CHAR

What Unix would call a ``character special file'', that is, a device that works on character streams such as a printer port or a console.

FILE_TYPE_PIPE

Either a named or anonymous pipe.

GetLogicalDrives

$uDriveBits= GetLogicalDrives()

Returns an unsigned value with one bit set for each drive letter currently defined. If ``A:'' is currently a valid drive letter, then the 1 bit will be set in $uDriveBits. If ``B:'' is valid, then the 2 bit will be set. If ``Z:'' is valid, then the 2**26 [0x4000000] bit will be set.

GetLogicalDriveStrings

$olOutLength= GetLogicalDriveStrings( $lBufSize, $osBuffer )

For each currently defined drive letter, a '\0'-terminated string of the path to the root of its file system is constructed. All of these strings are concatenated into a single larger string and an extra terminating '\0' is added. This larger string is returned in $osBuffer. Note that this includes drive letters that have been defined but that have no file system, such as drive letters assigned to unformatted partitions.

$lBufSize is the size of the buffer to allocate to store this list of strings. 26*4+1 is always sufficient and should usually be used.

$osBuffer is a scalar to be set to contain the constructed string.

$olOutLength is the number of bytes actually written to $osBuffer but length($osBuffer) can also be used to determine this.

For example, on a poorly equipped computer,

    GetLogicalDriveStrings( 4*26+1, $osBuffer );

might set $osBuffer to the 9-character string, "A:\\\0C:\\\0\0".

GetHandleInformation

GetHandleInformation( $hObject, $ouFlags )

Retrieves the flags associated with a Win32 native file handle or object handle.

$hObject is an open Win32 native file handle or an open Win32 native handle to some other type of object.

$ouFlags will be set to an unsigned value having zero or more of the bits HANDLE_FLAG_INHERIT and HANDLE_FLAG_PROTECT_FROM_CLOSE set. See the ":HANDLE_FLAG_" export class for the meanings of these bits.

GetOsFHandle

$hNativeHandle= GetOsFHandle( FILE )

Takes a Perl file handle [like STDIN] and returns the Win32 native file handle associated with it. See FdGetOsFHandle for more information about Win32 native file handles.

$hNativeHandle is set to a false value [and lastFileError() and $^E are set] if GetOsFHandle fails. GetOsFHandle returns "0 but true" in the impossible(?) case of the handle having a value of 0.

GetVolumeInformation

GetVolumeInformation( $sRootPath, $osVolName, $lVolName, $ouSerialNum, $ouMaxNameLen, $ouFsFlags, $osFsType, $lFsType )

Gets information about a file system volume, returning a true value if successful. On failure, returns a false value and sets fileLastError() and $^E.

$sRootPath is a string specifying the path to the root of the file system, for example, "C:/".

$osVolName is a scalar to be set to the string representing the volume name, also called the file system label. $lVolName is the number of bytes to allocate for the $osVolName buffer [see Buffer Sizes for more information].

$ouSerialNum is [] [for NULL] or will be set to the numeric value of the volume's serial number.

$ouMaxNameLen is [] [for NULL] or will be set to the maximum length allowed for a file name or directory name within the file system.

$osFsType is a scalar to be set to the string representing the file system type, such as "FAT" or "NTFS". $lFsType is the number of bytes to allocate for the $osFsType buffer [see Buffer Sizes for more information].

$ouFsFlags is [] [for NULL] or will be set to an unsigned integer with bits set indicating properties of the file system:

FS_CASE_IS_PRESERVED

The file system preserves the case of file names [usually true]. That is, it doesn't change the case of file names such as forcing them to upper- or lower-case.

FS_CASE_SENSITIVE

The file system supports the ability to not ignore the case of file names [but might ignore case the way you are using it]. That is, the file system has the ability to force you to get the letter case of a file's name exactly right to be able to open it. This is true for ``NTFS'' file systems, even though case in file names is usually still ignored.

FS_UNICODE_STORED_ON_DISK

The file system preserves Unicode in file names [true for ``NTFS''].

FS_PERSISTENT_ACLS

The file system supports setting Access Control Lists on files [true for ``NTFS''].

FS_FILE_COMPRESSION

The file system supports compression on a per-file basis [true for ``NTFS''].

FS_VOL_IS_COMPRESSED

The entire file system is compressed such as via ``DoubleSpace''.

IsRecognizedPartition

IsRecognizedPartition( $ivPartitionType )

Takes a partition type and returns whether that partition type is supported under Win32. $ivPartitonType is an integer value as from the operating system byte of a hard disk's DOS-compatible partition table [that is, a partition table for x86-based Win32, not, for example, one used with Windows NT for Alpha processors]. For example, the PartitionType member of the PARTITION_INFORMATION structure.

Common values for $ivPartitionType include PARTITION_FAT_12==1, PARTITION_FAT_16==4, PARTITION_EXTENDED==5, PARTITION_FAT32==0xB.

IsContainerPartition

IsContainerPartition( $ivPartitionType )

Takes a partition type and returns whether that partition is a ``container'' partition that is supported under Win32, that is, whether it is an ``extended'' partition that can contain ``logical'' partitions. $ivPartitonType is as for IsRecognizedPartition.

MoveFile

MoveFile( $sOldName, $sNewName )

Renames a file or directory. $sOldName is the name of the existing file or directory that is to be renamed. $sNewName is the new name to give the file or directory. Returns a true value if the move succeeds. For failure, returns a false value and sets fileLastErorr() and $^E to the reason for the failure.

Files can be ``renamed'' between file systems and the file contents and some attributes will be moved. Directories can only be renamed within one file system. If there is already a file or directory named $sNewName, then MoveFile will fail.

MoveFileEx

MoveFileEx( $sOldName, $sNewName, $uFlags )

Renames a file or directory. $sOldName is the name of the existing file or directory that is to be renamed. $sNewName is the new name to give the file or directory. Returns a true value if the move succeeds. For failure, returns a false value and sets fileLastErorr() and $^E to the reason for the failure.

$uFlags is an unsigned value with zero or more of the following bits set:

MOVEFILE_REPLACE_EXISTING

If this bit is set and a file [but not a directory] named $sNewName already exists, then it will be replaced by $sOldName. If this bit is not set then MoveFileEx will fail rather than replace an existing $sNewName.

MOVEFILE_COPY_ALLOWED

Allows files [but not directories] to be moved between file systems by copying the $sOldName file data and some attributes to $sNewName and then deleting $sOldName. If this bit is not set [or if $sOldName denotes a directory] and $sNewName refers to a different file system than $sOldName, then MoveFileEx will fail.

MOVEFILE_DELAY_UNTIL_REBOOT

Preliminary verifications are made and then an entry is added to the Registry to cause the rename [or delete] operation to be done the next time this copy of the operating system is booted [right after any automatic file system checks have completed]. This is not supported under Windows 95.

When this bit is set, $sNewName can be [] [for NULL] to indicate that $sOldName should be deleted during the next boot rather than renamed.

Setting both the MOVEFILE_COPY_ALLOWED and MOVEFILE_DELAY_UNTIL_REBOOT bits will cause MoveFileEx to fail.

MOVEFILE_WRITE_THROUGH

Ensures that MoveFileEx won't return until the operation has finished and been flushed to disk. This is not supported under Windows 95. Only affects file renames to another file system, forcing a buffer flush at the end of the copy operation.

OsFHandleOpen

OsFHandleOpen( FILE, $hNativeHandle, $sMode )

Opens a Perl file handle based on an already open Win32 native file handle [much like C's fdopen() does with a file descriptor]. Returns a true value if the open operation succeeded. For failure, returns a false value and sets $! [and possibly fileLastError() and $^E] to the reason for the failure.

FILE is a Perl file handle [in any of the supported forms, a bareword, a string, a typeglob, or a reference to a typeglob] that will be opened. If FILE is already open, it will automatically be closed before it is reopened.

$hNativeHandle is an open Win32 native file handle, probably the return value from CreateFile or createFile.

$sMode is string of zero or more letters from "rwatb". These are translated into a combination O_RDONLY ["r"], O_WRONLY ["w"], O_RDWR ["rw"], O_APPEND ["a"], O_TEXT ["t"], and O_BINARY ["b"] flags [see the the Fcntl manpage module] that is passed to OsFHandleOpenFd. Currently only O_APPEND and O_TEXT have any significance.

Also, a "r" and/or "w" in $sMode is used to decide how the file descriptor is converted into a Perl file handle, even though this doesn't appear to make a difference. One of the following is used:

    open( FILE, "<&=".$ivFd )   # "r" w/o "w"
    open( FILE, ">&=".$ivFd )   # "w" w/o "r"
    open( FILE, "+<&=".$ivFd )  # both "r" and "w"

OsFHandleOpen eventually calls the Win32-specific C routine _open_osfhandle() or Perl's ``improved'' version called win32_open_osfhandle(). Prior to Perl5.005, C's _open_osfhandle() is called which will fail if GetFileType($hNativeHandle) would return FILE_TYPE_UNKNOWN. For Perl5.005 and later, OsFHandleOpen calls win32_open_osfhandle() from the Perl DLL which doesn't have this restriction.

OsFHandleOpenFd

$ivFD= OsFHandleOpenFd( $hNativeHandle, $uMode )

Opens a file descriptor [$ivFD] based on an already open Win32 native file handle, $hNativeHandle. This just calls the Win32-specific C routine _open_osfhandle() or Perl's ``improved'' version called win32_open_osfhandle(). Prior to Perl5.005, C's _open_osfhandle() is called which will fail if GetFileType($hNativeHandle) would return FILE_TYPE_UNKNOWN. For Perl5.005 and later, OsFHandleOpenFd calls win32_open_osfhandle() from the Perl DLL which doesn't have this restriction.

$uMode the logical combination of zero or more O_* constants exported by the Fcntl module. Currently only O_APPEND and O_TEXT have any significance.

$ivFD will be non-negative if the open operation was successful. For failure, -1 is returned and $! [and possibly fileLastError() and $^E] is set to the reason for the failure.

QueryDosDevice

$olTargetLen= QueryDosDevice( $sDosDeviceName, $osTargetPath, $lTargetBuf )

Looks up the definition of a given ``DOS'' device name, yielding the active Windows NT native device name along with any currently dormant definitions.

$sDosDeviceName is the name of the ``DOS'' device whose definitions we want. For example, "C:", "COM1", or "PhysicalDrive0". If $sDosDeviceName is [] [for NULL], the list of all DOS device names is returned instead.

$osTargetPath will be assigned a string containing the list of definitions. The definitions are each '\0'-terminate and are concatenated into the string, most recent first, with an extra '\0' at the end of the whole string [see GetLogicalDriveStrings for a sample of this format].

$lTargetBuf is the size [in bytes] of the buffer to allocate for $osTargetPath. See Buffers Sizes for more information.

$olTargetLen is set to the number of bytes written to $osTargetPath but you can also use length($osTargetPath) to determine this.

For failure, 0 is returned and fileLastError() and $^E are set to the reason for the failure.

ReadFile

ReadFile( $hFile, $opBuffer, $lBytes, $olBytesRead, $pOverlapped )

Reads bytes from a file or file-like device. Returns a true value if the read operation was successful. For failure, returns a false value and sets fileLastError() and $^E for the reason for the failure.

$hFile is a Win32 native file handle that is already open to the file or device to read from.

$opBuffer will be set to a string containing the bytes read.

$lBytes is the number of bytes you would like to read. $opBuffer is automatically initialized to have a buffer large enough to hold that many bytes. Unlike other buffer sizes, $lBytes does not need to have a "=" prepended to it to prevent a larger value to be passed to the underlying Win32 ReadFile API. However, a leading "=" will be silently ignored, even if Perl warnings are enabled.

If $olBytesRead is not [], it will be set to the actual number of bytes read, though length($opBuffer) can also be used to determine this.

$pOverlapped is [] or is a OVERLAPPED structure packed into a string. This is only useful if $hFile was opened with the FILE_FLAG_OVERLAPPED flag set.

SetErrorMode

$uOldMode= SetErrorMode( $uNewMode )

Sets the mode controlling system error handling ∧ returns the previous mode value. Both $uOldMode and $uNewMode will have zero or more of the following bits set:

SEM_FAILCRITICALERRORS

If set, indicates that when a critical error is encountered, the call that triggered the error fails immediately. Normally this bit is not set, which means that a critical error causes a dialogue box to appear notifying the desktop user that some application has triggered a critical error. The dialogue box allows the desktop user to decide whether the critical error is returned to the process, is ignored, or the offending operation is retried.

This affects the CreateFile and GetVolumeInformation calls.

Setting this bit is useful for allowing you to check whether a floppy diskette is in the floppy drive.

SEM_NOALIGNMENTFAULTEXCEPT

If set, this causes memory access misalignment faults to be automatically fixed in a manner invisible to the process. This flag is ignored on x86-based versions of Windows NT. This flag is not supported on Windows 95.

SEM_NOGPFAULTERRORBOX

If set, general protection faults do not generate a dialogue box but can instead be handled by the process via an exception handler. This bit should not be set by programs that don't know how to handle such faults.

SEM_NOOPENFILEERRORBOX

If set, then when an attempt to continue reading from or writing to an already open file [usually on a removable medium like a floppy diskette] finds the file no longer available, the call will immediately fail. Normally this bit is not set, which means that instead a dialogue box will appear notifying the desktop user that some application has run into this problem. The dialogue box allows the desktop user to decide whether the failure is returned to the process, is ignored, or the offending operation is retried.

This affects the ReadFile and WriteFile calls.

SetFilePointer

$uNewPos= SetFilePointer( $hFile, $ivOffset, $ioivOffsetHigh, $uFromWhere )

The native Win32 version of seek(). SetFilePointer sets the position within a file where the next read or write operation will start from.

$hFile is a Win32 native file handle.

$uFromWhere is either FILE_BEGIN, FILE_CURRENT, or FILE_END, indicating that the new file position is being specified relative to the beginning of the file, the current file pointer, or the end of the file, respectively.

$ivOffset is [if $ioivOffsetHigh is []] the offset [in bytes] to the new file position from the position specified via $uFromWhere. If $ioivOffsetHigh is not [], then $ivOffset is converted to an unsigned value to be used as the low-order 4 bytes of the offset.

$ioivOffsetHigh can be [] [for NULL] to indicate that you are only specifying a 4-byte offset and the resulting file position will be 0xFFFFFFFE or less [just under 4GB]. Otherwise $ioivOfffsetHigh starts out with the high-order 4 bytes [signed] of the offset and gets set to the [unsigned] high-order 4 bytes of the resulting file position.

The underlying SetFilePointer returns 0xFFFFFFFF to indicate failure, but if $ioivOffsetHigh is not [], you would also have to check $^E to determine whether 0xFFFFFFFF indicates an error or not. Win32API::File::SetFilePointer does this checking for you and returns a false value if and only if the underlying SetFilePointer failed. For this reason, $uNewPos is set to "0 but true" if you set the file pointer to the beginning of the file [or any position with 0 for the low-order 4 bytes].

So the return value will be true if the seek operation was successful. For failure, a false value is returned and fileLastError() and $^E are set to the reason for the failure.

SetHandleInformation

SetHandleInformation( $hObject, $uMask, $uFlags )

Sets the flags associated with a Win32 native file handle or object handle. Returns a true value if the operation was successful. For failure, returns a false value and sets fileLastError() and $^E for the reason for the failure.

$hObject is an open Win32 native file handle or an open Win32 native handle to some other type of object.

$uMask is an unsigned value having one or more of the bits HANDLE_FLAG_INHERIT and HANDLE_FLAG_PROTECT_FROM_CLOSE set. Only bits set in $uMask will be modified by SetHandleInformation.

$uFlags is an unsigned value having zero or more of the bits HANDLE_FLAG_INHERIT and HANDLE_FLAG_PROTECT_FROM_CLOSE set. For each bit set in $uMask, the cooresponding bit in the handle's flags is set to the value of the cooresponding bit in $uFlags.

If $uOldFlags were the value of the handle's flags before the call to SetHandleInformation, then the value of the handle's flags afterward would be:

    ( $uOldFlags & ~$uMask ) | ( $uFlags & $uMask )

[at least as far as the HANDLE_FLAG_INHERIT and HANDLE_FLAG_PROTECT_FROM_CLOSE bits are concerned.]

See the ":HANDLE_FLAG_" export class for the meanings of these bits.

WriteFile

WriteFile( $hFile, $pBuffer, $lBytes, $ouBytesWritten, $pOverlapped )

Write bytes to a file or file-like device. Returns a true value if the operation was successful. For failure, returns a false value and sets fileLastError() and $^E for the reason for the failure.

$hFile is a Win32 native file handle that is already open to the file or device to be written to.

$pBuffer is a string containing the bytes to be written.

$lBytes is the number of bytes you would like to write. If $pBuffer is not at least $lBytes long, WriteFile croaks. You can specify 0 for $lBytes to write length($pBuffer) bytes. A leading "=" on $lBytes will be silently ignored, even if Perl warnings are enabled.

$ouBytesWritten will be set to the actual number of bytes written unless you specify it as [].

$pOverlapped is [] or is an OVERLAPPED structure packed into a string. This is only useful if $hFile was opened with the FILE_FLAG_OVERLAPPED flag set.

":FuncA"

The ASCII-specific functions. Each of these is just the same as the version without the trailing ``A''.

        CopyFileA
        CreateFileA
        DefineDosDeviceA
        DeleteFileA
        GetDriveTypeA
        GetLogicalDriveStringsA
        GetVolumeInformationA
        MoveFileA
        MoveFileExA
        QueryDosDeviceA

":FuncW"

The wide-character-specific (Unicode) functions. Each of these is just the same as the version without the trailing ``W'' except that strings are expected in Unicode and some lengths are measured as number of WCHARs instead of number of bytes, as indicated below.

CopyFileW

CopyFileW( $swOldFileName, $swNewFileName, $bFailIfExists )

$swOldFileName and $swNewFileName are Unicode strings.

CreateFileW

$hObject= CreateFileW( $swPath, $uAccess, $uShare, $pSecAttr, $uCreate, $uFlags, $hModel )

$swPath is Unicode.

DefineDosDeviceW

DefineDosDeviceW( $uFlags, $swDosDeviceName, $swTargetPath )

$swDosDeviceName and $swTargetPath are Unicode.

DeleteFileW

DeleteFileW( $swFileName )

$swFileName is Unicode.

GetDriveTypeW

$uDriveType= GetDriveTypeW( $swRootPath )

$swRootPath is Unicode.

GetLogicalDriveStringsW

$olwOutLength= GetLogicalDriveStringsW( $lwBufSize, $oswBuffer )

Unicode is stored in $oswBuffer. $lwBufSize and $olwOutLength are measured as number of WCHARs.

GetVolumeInformationW

GetVolumeInformationW( $swRootPath, $oswVolName, $lwVolName, $ouSerialNum, $ouMaxNameLen, $ouFsFlags, $oswFsType, $lwFsType )

$swRootPath is Unicode and Unicode is written to $oswVolName and $oswFsType. $lwVolName and $lwFsType are measures as number of WCHARs.

MoveFileW

MoveFileW( $swOldName, $swNewName )

$swOldName and $swNewName are Unicode.

MoveFileExW

MoveFileExW( $swOldName, $swNewName, $uFlags )

$swOldName and $swNewName are Unicode.

QueryDosDeviceW

$olwTargetLen= QueryDosDeviceW( $swDeviceName, $oswTargetPath, $lwTargetBuf )

$swDeviceName is Unicode and Unicode is written to $oswTargetPath. $lwTargetBuf and $olwTargetLen are measured as number of WCHARs.

":Misc"

Miscellaneous constants. Used for the $uCreate argument of CreateFile or the $uFromWhere argument of SetFilePointer. Plus INVALID_HANDLE_VALUE, which you usually won't need to check for since most routines translate it into a false value.

        CREATE_ALWAYS           CREATE_NEW              OPEN_ALWAYS
        OPEN_EXISTING           TRUNCATE_EXISTING       INVALID_HANDLE_VALUE
        FILE_BEGIN              FILE_CURRENT            FILE_END

":DDD_"

Constants for the $uFlags argument of DefineDosDevice.

        DDD_EXACT_MATCH_ON_REMOVE
        DDD_RAW_TARGET_PATH
        DDD_REMOVE_DEFINITION

":DRIVE_"

Constants returned by GetDriveType.

        DRIVE_UNKNOWN           DRIVE_NO_ROOT_DIR       DRIVE_REMOVABLE
        DRIVE_FIXED             DRIVE_REMOTE            DRIVE_CDROM
        DRIVE_RAMDISK

":FILE_"

Specific types of access to files that can be requested via the $uAccess argument to CreateFile.

        FILE_READ_DATA                  FILE_LIST_DIRECTORY
        FILE_WRITE_DATA                 FILE_ADD_FILE
        FILE_APPEND_DATA                FILE_ADD_SUBDIRECTORY
        FILE_CREATE_PIPE_INSTANCE       FILE_READ_EA
        FILE_WRITE_EA                   FILE_EXECUTE
        FILE_TRAVERSE                   FILE_DELETE_CHILD
        FILE_READ_ATTRIBUTES            FILE_WRITE_ATTRIBUTES
        FILE_ALL_ACCESS                 FILE_GENERIC_READ
        FILE_GENERIC_WRITE              FILE_GENERIC_EXECUTE )],

":FILE_ATTRIBUTE_"

File attribute constants. Returned by attrLetsToBits and used in the $uFlags argument to CreateFile.

        FILE_ATTRIBUTE_ARCHIVE          FILE_ATTRIBUTE_COMPRESSED
        FILE_ATTRIBUTE_HIDDEN           FILE_ATTRIBUTE_NORMAL
        FILE_ATTRIBUTE_OFFLINE          FILE_ATTRIBUTE_READONLY
        FILE_ATTRIBUTE_SYSTEM           FILE_ATTRIBUTE_TEMPORARY

":FILE_FLAG_"

File option flag constants. Used in the $uFlags argument to CreateFile.

        FILE_FLAG_BACKUP_SEMANTICS      FILE_FLAG_DELETE_ON_CLOSE
        FILE_FLAG_NO_BUFFERING          FILE_FLAG_OVERLAPPED
        FILE_FLAG_POSIX_SEMANTICS       FILE_FLAG_RANDOM_ACCESS
        FILE_FLAG_SEQUENTIAL_SCAN       FILE_FLAG_WRITE_THROUGH

":FILE_SHARE_"

File sharing constants. Used in the $uShare argument to CreateFile.

        FILE_SHARE_DELETE       FILE_SHARE_READ         FILE_SHARE_WRITE

":FILE_TYPE_"

File type constants. Returned by GetFileType.

        FILE_TYPE_CHAR          FILE_TYPE_DISK
        FILE_TYPE_PIPE          FILE_TYPE_UNKNOWN

":FS_"

File system characteristics constants. Placed in the $ouFsFlags argument to GetVolumeInformation.

        FS_CASE_IS_PRESERVED            FS_CASE_SENSITIVE
        FS_UNICODE_STORED_ON_DISK       FS_PERSISTENT_ACLS 
        FS_FILE_COMPRESSION             FS_VOL_IS_COMPRESSED

":HANDLE_FLAG_"

Flag bits modifying the behavior of an object handle and accessed via GetHandleInformation and SetHandleInformation.

HANDLE_FLAG_INHERIT

If this bit is set, then children of this process who inherit handles [that is, processes created by calls to the Win32 CreateProcess API with the bInheritHandles parameter specified as TRUE], will inherit this particular object handle.

HANDLE_FLAG_PROTECT_FROM_CLOSE

If this bit is set, then calls to CloseHandle against this handle will be ignored, leaving the handle open and usable.

":IOCTL_STORAGE_"

I/O control operations for generic storage devices. Used in the $uIoControlCode argument to DeviceIoControl. Includes IOCTL_STORAGE_CHECK_VERIFY, IOCTL_STORAGE_MEDIA_REMOVAL, IOCTL_STORAGE_EJECT_MEDIA, IOCTL_STORAGE_LOAD_MEDIA, IOCTL_STORAGE_RESERVE, IOCTL_STORAGE_RELEASE, IOCTL_STORAGE_FIND_NEW_DEVICES, and IOCTL_STORAGE_GET_MEDIA_TYPES.

IOCTL_STORAGE_CHECK_VERIFY

Verify that a device's media is accessible. $pInBuf and $opOutBuf should both be []. If DeviceIoControl returns a true value, then the media is currently accessible.

IOCTL_STORAGE_MEDIA_REMOVAL

Allows the device's media to be locked or unlocked. $opOutBuf should be []. $pInBuf should be a PREVENT_MEDIA_REMOVAL data structure, which is simply an interger containing a boolean value:

    $pInBuf= pack( "i", $bPreventMediaRemoval );

IOCTL_STORAGE_EJECT_MEDIA

Requests that the device eject the media. $pInBuf and $opOutBuf should both be [].

IOCTL_STORAGE_LOAD_MEDIA

Requests that the device load the media. $pInBuf and $opOutBuf should both be [].

IOCTL_STORAGE_RESERVE

Requests that the device be reserved. $pInBuf and $opOutBuf should both be [].

IOCTL_STORAGE_RELEASE

Releases a previous device reservation. $pInBuf and $opOutBuf should both be [].

IOCTL_STORAGE_FIND_NEW_DEVICES

No documentation on this IOCTL operation was found.

IOCTL_STORAGE_GET_MEDIA_TYPES

Requests information about the type of media supported by the device. $pInBuf should be []. $opOutBuf will be set to contain a vector of DISK_GEOMETRY data structures, which can be decoded via:

    # Calculate the number of DISK_GEOMETRY structures returned:
    my $cStructs= length($opOutBuf)/(4+4+4+4+4+4);
    my @fields= unpack( "L l I L L L" x $cStructs, $opOutBuf )
    my( @ucCylsLow, @ivcCylsHigh, @uMediaType, @uTracksPerCyl,
      @uSectsPerTrack, @uBytesPerSect )= ();
    while(  @fields  ) {
        push( @ucCylsLow, unshift @fields );
        push( @ivcCylsHigh, unshift @fields );
        push( @uMediaType, unshift @fields );
        push( @uTracksPerCyl, unshift @fields );
        push( @uSectsPerTrack, unshift @fields );
        push( @uBytesPerSect, unshift @fields );
    }

For the $ith type of supported media, the following variables will contain the following data.

$ucCylsLow[$i]

The low-order 4 bytes of the total number of cylinders.

$ivcCylsHigh[$i]

The high-order 4 bytes of the total number of cylinders.

$uMediaType[$i]

A code for the type of media. See the ":MEDIA_TYPE" export class.

$uTracksPerCyl[$i]

The number of tracks in each cylinder.

$uSectsPerTrack[$i]

The number of sectors in each track.

$uBytesPerSect[$i]

The number of bytes in each sector.

":IOCTL_DISK_"

I/O control operations for disk devices. Used in the $uIoControlCode argument to DeviceIoControl. Most of these are to be used on physical drive devices like "//./PhysicalDrive0". However, IOCTL_DISK_GET_PARTITION_INFO and IOCTL_DISK_SET_PARTITION_INFO should only be used on a single-partition device like "//./C:". Also, IOCTL_DISK_GET_MEDIA_TYPES is documented as having been superceded but is still useful when used on a floppy device like "//./A:".

Includes IOCTL_DISK_FORMAT_TRACKS, IOCTL_DISK_FORMAT_TRACKS_EX, IOCTL_DISK_GET_DRIVE_GEOMETRY, IOCTL_DISK_GET_DRIVE_LAYOUT, IOCTL_DISK_GET_MEDIA_TYPES, IOCTL_DISK_GET_PARTITION_INFO, IOCTL_DISK_HISTOGRAM_DATA, IOCTL_DISK_HISTOGRAM_RESET, IOCTL_DISK_HISTOGRAM_STRUCTURE, IOCTL_DISK_IS_WRITABLE, IOCTL_DISK_LOGGING, IOCTL_DISK_PERFORMANCE, IOCTL_DISK_REASSIGN_BLOCKS, IOCTL_DISK_REQUEST_DATA, IOCTL_DISK_REQUEST_STRUCTURE, IOCTL_DISK_SET_DRIVE_LAYOUT, IOCTL_DISK_SET_PARTITION_INFO, and IOCTL_DISK_VERIFY.

IOCTL_DISK_GET_DRIVE_GEOMETRY

Request information about the size and geometry of the disk. $pInBuf should be []. $opOutBuf will be set to a DISK_GEOMETRY data structure which can be decode via:

    ( $ucCylsLow, $ivcCylsHigh, $uMediaType, $uTracksPerCyl,
      $uSectsPerTrack, $uBytesPerSect )= unpack( "L l I L L L", $opOutBuf );

$ucCylsLow

The low-order 4 bytes of the total number of cylinders.

$ivcCylsHigh

The high-order 4 bytes of the total number of cylinders.

$uMediaType

A code for the type of media. See the ":MEDIA_TYPE" export class.

$uTracksPerCyl

The number of tracks in each cylinder.

$uSectsPerTrack

The number of sectors in each track.

$uBytesPerSect

The number of bytes in each sector.

IOCTL_DISK_GET_PARTITION_INFO

Request information about the size and geometry of the partition. $pInBuf should be []. $opOutBuf will be set to a PARTITION_INFORMATION data structure which can be decode via:

    ( $uStartLow, $ivStartHigh, $ucHiddenSects, $uPartitionSeqNumber,
      $uPartitionType, $bActive, $bRecognized, $bToRewrite )=
      unpack( "L l L L C c c c", $opOutBuf );

$uStartLow and $ivStartHigh

The low-order and high-order [respectively] 4 bytes of the starting offset of the partition, measured in bytes.

$ucHiddenSects

The number of ``hidden'' sectors for this partition. Actually this is the number of sectors found prior to this partiton, that is, the starting offset [as found in $uStartLow and $ivStartHigh] divided by the number of bytes per sector.

$uPartitionSeqNumber

The sequence number of this partition. Partitions are numbered starting as 1 [with ``partition 0'' meaning the entire disk]. Sometimes this field may be 0 and you'll have to infer the partition sequence number from how many partitions preceed it on the disk.

$uPartitionType

The type of partition. See the ":PARTITION_" export class for a list of known types. See also IsRecognizedPartition and IsContainerPartition.

$bActive

1 for the active [boot] partition, 0 otherwise.

$bRecognized

Whether this type of partition is support under Win32.

$bToRewrite

Whether to update this partition information. This field is not used by IOCTL_DISK_GET_PARTITION_INFO. For IOCTL_DISK_SET_DRIVE_LAYOUT, you must set this field to a true value for any partitions you wish to have changed, added, or deleted.

IOCTL_DISK_SET_PARTITION_INFO

Change the type of the partition. $opOutBuf should be []. $pInBuf should be a SET_PARTITION_INFORMATION data structure which is just a single byte containing the new parition type [see the ":PARTITION_" export class for a list of known types]:

    $pInBuf= pack( "C", $uPartitionType );

IOCTL_DISK_GET_DRIVE_LAYOUT

Request information about the disk layout. $pInBuf should be []. $opOutBuf will be set to contain DRIVE_LAYOUT_INFORMATION structure including several PARTITION_INFORMATION structures:

    my( $cPartitions, $uDiskSignature )= unpack( "L L", $opOutBuf );
    my @fields= unpack( "x8" . ( "L l L L C c c c" x $cPartitions ),
                        $opOutBuf );
    my( @uStartLow, @ivStartHigh, @ucHiddenSects,
      @uPartitionSeqNumber, @uPartitionType, @bActive,
      @bRecognized, @bToRewrite )= ();
    for(  1..$cPartition  ) {
        push( @uStartLow, unshift @fields );
        push( @ivStartHigh, unshift @fields );
        push( @ucHiddenSects, unshift @fields );
        push( @uPartitionSeqNumber, unshift @fields );
        push( @uPartitionType, unshift @fields );
        push( @bActive, unshift @fields );
        push( @bRecognized, unshift @fields );
        push( @bToRewrite, unshift @fields );
    }

$cPartitions

If the number of partitions on the disk.

$uDiskSignature

Is the disk signature, a unique number assigned by Disk Administrator [WinDisk.exe] and used to identify the disk. This allows drive letters for partitions on that disk to remain constant even if the SCSI Target ID of the disk gets changed.

See IOCTL_DISK_GET_PARTITION_INFORMATION for information on the remaining these fields.

IOCTL_DISK_GET_MEDIA_TYPES

Is supposed to be superseded by IOCTL_STORAGE_GET_MEDIA_TYPES but is still useful for determining the types of floppy diskette formats that can be produced by a given floppy drive. See ex/FormatFloppy.plx for an example.

IOCTL_DISK_SET_DRIVE_LAYOUT

Change the partition layout of the disk. $pOutBuf should be []. $pInBuf should be a DISK_LAYOUT_INFORMATION data structure including several PARTITION_INFORMATION data structures.

    # Already set:  $cPartitions, $uDiskSignature, @uStartLow, @ivStartHigh,
    #   @ucHiddenSects, @uPartitionSeqNumber, @uPartitionType, @bActive,
    #   @bRecognized, and @bToRewrite.
    my( @fields, $prtn )= ();
    for $prtn (  1..$cPartition  ) {
        push( @fields, $uStartLow[$prtn-1], $ivStartHigh[$prtn-1],
            $ucHiddenSects[$prtn-1], $uPartitionSeqNumber[$prtn-1],
            $uPartitionType[$prtn-1], $bActive[$prtn-1],
            $bRecognized[$prtn-1], $bToRewrite[$prtn-1] );
    }
    $pInBuf= pack( "L L" . ( "L l L L C c c c" x $cPartitions ),
                   $cPartitions, $uDiskSignature, @fields );

To delete a partition, zero out all fields except for $bToRewrite which should be set to 1. To add a partition, increment $cPartitions and add the information for the new partition into the arrays, making sure that you insert 1 into @bToRewrite.

See IOCTL_DISK_GET_DRIVE_LAYOUT and IOCTL_DISK_GET_PARITITON_INFORMATION for descriptions of the fields.

IOCTL_DISK_VERIFY

Performs a logical format of [part of] the disk. $opOutBuf should be []. $pInBuf should contain a VERIFY_INFORMATION data structure:

    $pInBuf= pack( "L l L",
                   $uStartOffsetLow, $ivStartOffsetHigh, $uLength );

$uStartOffsetLow and $ivStartOffsetHigh

The low-order and high-order [respectively] 4 bytes of the offset [in bytes] where the formatting should begin.

$uLength

The length [in bytes] of the section to be formatted.

IOCTL_DISK_FORMAT_TRACKS

Format a range of tracks on the disk. $opOutBuf should be []. $pInBuf should contain a FORMAT_PARAMETERS data structure:

    $pInBuf= pack( "L L L L L", $uMediaType,
                   $uStartCyl, $uEndCyl, $uStartHead, $uEndHead );

$uMediaType if the type of media to be formatted. Mostly used to specify the density to use when formatting a floppy diskette. See the ":MEDIA_TYPE" export class for more information.

The remaining fields specify the starting and ending cylinder and head of the range of tracks to be formatted.

IOCTL_DISK_REASSIGN_BLOCKS

Reassign a list of disk blocks to the disk's spare-block pool. $opOutBuf should be []. $pInBuf should be a REASSIGN_BLOCKS data structure:

    $pInBuf= pack( "S S L*", 0, $cBlocks, @uBlockNumbers );

IOCTL_DISK_PERFORMANCE

Request information about disk performance. $pInBuf should be []. $opOutBuf will be set to contain a DISK_PERFORMANCE data structure:

    my( $ucBytesReadLow, $ivcBytesReadHigh,
        $ucBytesWrittenLow, $ivcBytesWrittenHigh,
        $uReadTimeLow, $ivReadTimeHigh,
        $uWriteTimeLow, $ivWriteTimeHigh,
        $ucReads, $ucWrites, $uQueueDepth )=
        unpack( "L l L l L l L l L L L", $opOutBuf );

IOCTL_DISK_IS_WRITABLE

No documentation on this IOCTL operation was found.

IOCTL_DISK_LOGGING

Control disk logging. Little documentation for this IOCTL operation was found. It makes use of a DISK_LOGGING data structure:

DISK_LOGGING_START

Start logging each disk request in a buffer internal to the disk device driver of size $uLogBufferSize:

    $pInBuf= pack( "C L L", 0, 0, $uLogBufferSize );

DISK_LOGGING_STOP

Stop loggin each disk request:

    $pInBuf= pack( "C L L", 1, 0, 0 );

DISK_LOGGING_DUMP

Copy the interal log into the supplied buffer:

    $pLogBuffer= ' ' x $uLogBufferSize
    $pInBuf= pack( "C P L", 2, $pLogBuffer, $uLogBufferSize );

    ( $uByteOffsetLow[$i], $ivByteOffsetHigh[$i],
      $uStartTimeLow[$i], $ivStartTimeHigh[$i],
      $uEndTimeLog[$i], $ivEndTimeHigh[$i],
      $hVirtualAddress[$i], $ucBytes[$i],
      $uDeviceNumber[$i], $bWasReading[$i] )=
      unpack( "x".(8+8+8+4+4+1+1+2)." L l L l L l L L C c x2", $pLogBuffer );

DISK_LOGGING_BINNING

Keep statics grouped into bins based on request sizes.

    $pInBuf= pack( "C P L", 3, $pUnknown, $uUnknownSize );

IOCTL_DISK_FORMAT_TRACKS_EX

No documentation on this IOCTL is included.

IOCTL_DISK_HISTOGRAM_STRUCTURE

No documentation on this IOCTL is included.

IOCTL_DISK_HISTOGRAM_DATA

No documentation on this IOCTL is included.

IOCTL_DISK_HISTOGRAM_RESET

No documentation on this IOCTL is included.

IOCTL_DISK_REQUEST_STRUCTURE

No documentation on this IOCTL operation was found.

IOCTL_DISK_REQUEST_DATA

No documentation on this IOCTL operation was found.

":GENERIC_"

Constants specifying generic access permissions that are not specific to one type of object.

        GENERIC_ALL                     GENERIC_EXECUTE
        GENERIC_READ                    GENERIC_WRITE

":MEDIA_TYPE"

Different classes of media that a device can support. Used in the $uMediaType field of a DISK_GEOMETRY structure.

Unknown

Format is unknown.

F5_1Pt2_512

5.25`` floppy, 1.2MB [really 1,200KB] total space, 512 bytes/sector.

F3_1Pt44_512

3.5`` floppy, 1.44MB [really 1,440KB] total space, 512 bytes/sector.

F3_2Pt88_512

3.5`` floppy, 2.88MB [really 2,880KB] total space, 512 bytes/sector.

F3_20Pt8_512

3.5`` floppy, 20.8MB total space, 512 bytes/sector.

F3_720_512

3.5`` floppy, 720KB total space, 512 bytes/sector.

F5_360_512

5.25`` floppy, 360KB total space, 512 bytes/sector.

F5_320_512

5.25`` floppy, 320KB total space, 512 bytes/sector.

F5_320_1024

5.25`` floppy, 320KB total space, 1024 bytes/sector.

F5_180_512

5.25`` floppy, 180KB total space, 512 bytes/sector.

F5_160_512

5.25`` floppy, 160KB total space, 512 bytes/sector.

RemovableMedia

Some type of removable media other than a floppy diskette.

FixedMedia

A fixed hard disk.

F3_120M_512

3.5`` floppy, 120MB total space.

":MOVEFILE_"

Constants for use in $uFlags arguments to MoveFileEx.

        MOVEFILE_COPY_ALLOWED           MOVEFILE_DELAY_UNTIL_REBOOT
        MOVEFILE_REPLACE_EXISTING       MOVEFILE_WRITE_THROUGH

":SECURITY_"

Security quality of service values that can be used in the $uFlags argument to CreateFile if opening the client side of a named pipe.

        SECURITY_ANONYMOUS              SECURITY_CONTEXT_TRACKING
        SECURITY_DELEGATION             SECURITY_EFFECTIVE_ONLY
        SECURITY_IDENTIFICATION         SECURITY_IMPERSONATION
        SECURITY_SQOS_PRESENT

":SEM_"

Constants to be used with SetErrorMode.

        SEM_FAILCRITICALERRORS          SEM_NOGPFAULTERRORBOX
        SEM_NOALIGNMENTFAULTEXCEPT      SEM_NOOPENFILEERRORBOX

":PARTITION_"

Constants describing partition types.

        PARTITION_ENTRY_UNUSED          PARTITION_FAT_12
        PARTITION_XENIX_1               PARTITION_XENIX_2
        PARTITION_FAT_16                PARTITION_EXTENDED
        PARTITION_HUGE                  PARTITION_IFS
        PARTITION_FAT32                 PARTITION_FAT32_XINT13
        PARTITION_XINT13                PARTITION_XINT13_EXTENDED
        PARTITION_PREP                  PARTITION_UNIX
        VALID_NTFT                      PARTITION_NTFT

":ALL"

All of the above.

BUGS

None known at this time.

AUTHOR

Tye McQueen, tye@metronet.com, http://www.metronet.com/~tye/.

SEE ALSO

The pyramids.