Documentation / ioctl / cdrom.txt

Based on kernel version 4.16.1. Page generated on 2018-04-09 11:53 EST.

			Summary of CDROM ioctl calls.
			============================
	
			Edward A. Falk <efalk@google.com>
	
			November, 2004
	
	This document attempts to describe the ioctl(2) calls supported by
	the CDROM layer.  These are by-and-large implemented (as of Linux 2.6)
	in drivers/cdrom/cdrom.c and drivers/block/scsi_ioctl.c
	
	ioctl values are listed in <linux/cdrom.h>.  As of this writing, they
	are as follows:
	
		CDROMPAUSE		Pause Audio Operation
		CDROMRESUME		Resume paused Audio Operation
		CDROMPLAYMSF		Play Audio MSF (struct cdrom_msf)
		CDROMPLAYTRKIND		Play Audio Track/index (struct cdrom_ti)
		CDROMREADTOCHDR		Read TOC header (struct cdrom_tochdr)
		CDROMREADTOCENTRY	Read TOC entry (struct cdrom_tocentry)
		CDROMSTOP		Stop the cdrom drive
		CDROMSTART		Start the cdrom drive
		CDROMEJECT		Ejects the cdrom media
		CDROMVOLCTRL		Control output volume (struct cdrom_volctrl)
		CDROMSUBCHNL		Read subchannel data (struct cdrom_subchnl)
		CDROMREADMODE2		Read CDROM mode 2 data (2336 Bytes)
						   (struct cdrom_read)
		CDROMREADMODE1		Read CDROM mode 1 data (2048 Bytes)
						   (struct cdrom_read)
		CDROMREADAUDIO		(struct cdrom_read_audio)
		CDROMEJECT_SW		enable(1)/disable(0) auto-ejecting
		CDROMMULTISESSION	Obtain the start-of-last-session
					  address of multi session disks
					  (struct cdrom_multisession)
		CDROM_GET_MCN		Obtain the "Universal Product Code"
					   if available (struct cdrom_mcn)
		CDROM_GET_UPC		Deprecated, use CDROM_GET_MCN instead.
		CDROMRESET		hard-reset the drive
		CDROMVOLREAD		Get the drive's volume setting
						  (struct cdrom_volctrl)
		CDROMREADRAW		read data in raw mode (2352 Bytes)
						   (struct cdrom_read)
		CDROMREADCOOKED		read data in cooked mode
		CDROMSEEK		seek msf address
		CDROMPLAYBLK		scsi-cd only, (struct cdrom_blk)
		CDROMREADALL		read all 2646 bytes
		CDROMGETSPINDOWN	return 4-bit spindown value
		CDROMSETSPINDOWN	set 4-bit spindown value
		CDROMCLOSETRAY		pendant of CDROMEJECT
		CDROM_SET_OPTIONS	Set behavior options
		CDROM_CLEAR_OPTIONS	Clear behavior options
		CDROM_SELECT_SPEED	Set the CD-ROM speed
		CDROM_SELECT_DISC	Select disc (for juke-boxes)
		CDROM_MEDIA_CHANGED	Check is media changed
		CDROM_DRIVE_STATUS	Get tray position, etc.
		CDROM_DISC_STATUS	Get disc type, etc.
		CDROM_CHANGER_NSLOTS	Get number of slots
		CDROM_LOCKDOOR		lock or unlock door
		CDROM_DEBUG		Turn debug messages on/off
		CDROM_GET_CAPABILITY	get capabilities
		CDROMAUDIOBUFSIZ	set the audio buffer size
		DVD_READ_STRUCT		Read structure
		DVD_WRITE_STRUCT	Write structure
		DVD_AUTH		Authentication
		CDROM_SEND_PACKET	send a packet to the drive
		CDROM_NEXT_WRITABLE	get next writable block
		CDROM_LAST_WRITTEN	get last block written on disc
	
	
	The information that follows was determined from reading kernel source
	code.  It is likely that some corrections will be made over time.
	
	
	
	
	
	
	
	General:
	
		Unless otherwise specified, all ioctl calls return 0 on success
		and -1 with errno set to an appropriate value on error.  (Some
		ioctls return non-negative data values.)
	
		Unless otherwise specified, all ioctl calls return -1 and set
		errno to EFAULT on a failed attempt to copy data to or from user
		address space.
	
		Individual drivers may return error codes not listed here.
	
		Unless otherwise specified, all data structures and constants
		are defined in <linux/cdrom.h>
	
	
	
	
	CDROMPAUSE			Pause Audio Operation
	
		usage:
	
		  ioctl(fd, CDROMPAUSE, 0);
	
		inputs:		none
	
		outputs:	none
	
		error return:
		  ENOSYS	cd drive not audio-capable.
	
	
	CDROMRESUME			Resume paused Audio Operation
	
		usage:
	
		  ioctl(fd, CDROMRESUME, 0);
	
		inputs:		none
	
		outputs:	none
	
		error return:
		  ENOSYS	cd drive not audio-capable.
	
	
	CDROMPLAYMSF			Play Audio MSF (struct cdrom_msf)
	
		usage:
	
		  struct cdrom_msf msf;
		  ioctl(fd, CDROMPLAYMSF, &msf);
	
		inputs:
		  cdrom_msf structure, describing a segment of music to play
	
		outputs:	none
	
		error return:
		  ENOSYS	cd drive not audio-capable.
	
		notes:
		  MSF stands for minutes-seconds-frames
		  LBA stands for logical block address
	
		  Segment is described as start and end times, where each time
		  is described as minutes:seconds:frames.  A frame is 1/75 of
		  a second.
	
	
	CDROMPLAYTRKIND			Play Audio Track/index (struct cdrom_ti)
	
		usage:
	
		  struct cdrom_ti ti;
		  ioctl(fd, CDROMPLAYTRKIND, &ti);
	
		inputs:
		  cdrom_ti structure, describing a segment of music to play
	
		outputs:	none
	
		error return:
		  ENOSYS	cd drive not audio-capable.
	
		notes:
		  Segment is described as start and end times, where each time
		  is described as a track and an index.
	
	
	
	CDROMREADTOCHDR			Read TOC header (struct cdrom_tochdr)
	
		usage:
	
		  cdrom_tochdr header;
		  ioctl(fd, CDROMREADTOCHDR, &header);
	
		inputs:
		  cdrom_tochdr structure
	
		outputs:
		  cdrom_tochdr structure
	
		error return:
		  ENOSYS	cd drive not audio-capable.
	
	
	
	CDROMREADTOCENTRY		Read TOC entry (struct cdrom_tocentry)
	
		usage:
	
		  struct cdrom_tocentry entry;
		  ioctl(fd, CDROMREADTOCENTRY, &entry);
	
		inputs:
		  cdrom_tocentry structure
	
		outputs:
		  cdrom_tocentry structure
	
		error return:
		  ENOSYS	cd drive not audio-capable.
		  EINVAL	entry.cdte_format not CDROM_MSF or CDROM_LBA
		  EINVAL	requested track out of bounds
		  EIO		I/O error reading TOC
	
		notes:
		  TOC stands for Table Of Contents
		  MSF stands for minutes-seconds-frames
		  LBA stands for logical block address
	
	
	
	CDROMSTOP			Stop the cdrom drive
	
		usage:
	
		  ioctl(fd, CDROMSTOP, 0);
	
		inputs:		none
	
		outputs:	none
	
		error return:
		  ENOSYS	cd drive not audio-capable.
	
		notes:
		  Exact interpretation of this ioctl depends on the device,
		  but most seem to spin the drive down.
	
	
	CDROMSTART			Start the cdrom drive
	
		usage:
	
		  ioctl(fd, CDROMSTART, 0);
	
		inputs:		none
	
		outputs:	none
	
		error return:
		  ENOSYS	cd drive not audio-capable.
	
		notes:
		  Exact interpretation of this ioctl depends on the device,
		  but most seem to spin the drive up and/or close the tray.
		  Other devices ignore the ioctl completely.
	
	
	CDROMEJECT			Ejects the cdrom media
	
		usage:
	
		  ioctl(fd, CDROMEJECT, 0);
	
		inputs:		none
	
		outputs:	none
	
		error returns:
		  ENOSYS	cd drive not capable of ejecting
		  EBUSY		other processes are accessing drive, or door is locked
	
		notes:
		  See CDROM_LOCKDOOR, below.
	
	
	
	CDROMCLOSETRAY			pendant of CDROMEJECT
	
		usage:
	
		  ioctl(fd, CDROMCLOSETRAY, 0);
	
		inputs:		none
	
		outputs:	none
	
		error returns:
		  ENOSYS	cd drive not capable of closing the tray
		  EBUSY		other processes are accessing drive, or door is locked
	
		notes:
		  See CDROM_LOCKDOOR, below.
	
	
	
	CDROMVOLCTRL			Control output volume (struct cdrom_volctrl)
	
		usage:
	
		  struct cdrom_volctrl volume;
		  ioctl(fd, CDROMVOLCTRL, &volume);
	
		inputs:
		  cdrom_volctrl structure containing volumes for up to 4
		  channels.
	
		outputs:	none
	
		error return:
		  ENOSYS	cd drive not audio-capable.
	
	
	
	CDROMVOLREAD			Get the drive's volume setting
						  (struct cdrom_volctrl)
	
		usage:
	
		  struct cdrom_volctrl volume;
		  ioctl(fd, CDROMVOLREAD, &volume);
	
		inputs:		none
	
		outputs:
		  The current volume settings.
	
		error return:
		  ENOSYS	cd drive not audio-capable.
	
	
	
	CDROMSUBCHNL			Read subchannel data (struct cdrom_subchnl)
	
		usage:
	
		  struct cdrom_subchnl q;
		  ioctl(fd, CDROMSUBCHNL, &q);
	
		inputs:
		  cdrom_subchnl structure
	
		outputs:
		  cdrom_subchnl structure
	
		error return:
		  ENOSYS	cd drive not audio-capable.
		  EINVAL	format not CDROM_MSF or CDROM_LBA
	
		notes:
		  Format is converted to CDROM_MSF or CDROM_LBA
		  as per user request on return
	
	
	
	CDROMREADRAW			read data in raw mode (2352 Bytes)
						   (struct cdrom_read)
	
		usage:
	
		  union {
		    struct cdrom_msf msf;		/* input */
		    char buffer[CD_FRAMESIZE_RAW];	/* return */
		  } arg;
		  ioctl(fd, CDROMREADRAW, &arg);
	
		inputs:
		  cdrom_msf structure indicating an address to read.
		  Only the start values are significant.
	
		outputs:
		  Data written to address provided by user.
	
		error return:
		  EINVAL	address less than 0, or msf less than 0:2:0
		  ENOMEM	out of memory
	
		notes:
		  As of 2.6.8.1, comments in <linux/cdrom.h> indicate that this
		  ioctl accepts a cdrom_read structure, but actual source code
		  reads a cdrom_msf structure and writes a buffer of data to
		  the same address.
	
		  MSF values are converted to LBA values via this formula:
	
		    lba = (((m * CD_SECS) + s) * CD_FRAMES + f) - CD_MSF_OFFSET;
	
	
	
	
	CDROMREADMODE1			Read CDROM mode 1 data (2048 Bytes)
						   (struct cdrom_read)
	
		notes:
		  Identical to CDROMREADRAW except that block size is
		  CD_FRAMESIZE (2048) bytes
	
	
	
	CDROMREADMODE2			Read CDROM mode 2 data (2336 Bytes)
						   (struct cdrom_read)
	
		notes:
		  Identical to CDROMREADRAW except that block size is
		  CD_FRAMESIZE_RAW0 (2336) bytes
	
	
	
	CDROMREADAUDIO			(struct cdrom_read_audio)
	
		usage:
	
		  struct cdrom_read_audio ra;
		  ioctl(fd, CDROMREADAUDIO, &ra);
	
		inputs:
		  cdrom_read_audio structure containing read start
		  point and length
	
		outputs:
		  audio data, returned to buffer indicated by ra
	
		error return:
		  EINVAL	format not CDROM_MSF or CDROM_LBA
		  EINVAL	nframes not in range [1 75]
		  ENXIO		drive has no queue (probably means invalid fd)
		  ENOMEM	out of memory
	
	
	CDROMEJECT_SW			enable(1)/disable(0) auto-ejecting
	
		usage:
	
		  int val;
		  ioctl(fd, CDROMEJECT_SW, val);
	
		inputs:
		  Flag specifying auto-eject flag.
	
		outputs:	none
	
		error return:
		  ENOSYS	Drive is not capable of ejecting.
		  EBUSY		Door is locked
	
	
	
	
	CDROMMULTISESSION		Obtain the start-of-last-session
					  address of multi session disks
					  (struct cdrom_multisession)
		usage:
	
		  struct cdrom_multisession ms_info;
		  ioctl(fd, CDROMMULTISESSION, &ms_info);
	
		inputs:
		  cdrom_multisession structure containing desired
		  format.
	
		outputs:
		  cdrom_multisession structure is filled with last_session
		  information.
	
		error return:
		  EINVAL	format not CDROM_MSF or CDROM_LBA
	
	
	CDROM_GET_MCN			Obtain the "Universal Product Code"
					   if available (struct cdrom_mcn)
	
		usage:
	
		  struct cdrom_mcn mcn;
		  ioctl(fd, CDROM_GET_MCN, &mcn);
	
		inputs:		none
	
		outputs:
		  Universal Product Code
	
		error return:
		  ENOSYS	Drive is not capable of reading MCN data.
	
		notes:
		  Source code comments state:
	
		    The following function is implemented, although very few
		    audio discs give Universal Product Code information, which
		    should just be the Medium Catalog Number on the box.  Note,
		    that the way the code is written on the CD is /not/ uniform
		    across all discs!
	
	
	
	
	CDROM_GET_UPC			CDROM_GET_MCN  (deprecated)
	
		Not implemented, as of 2.6.8.1
	
	
	
	CDROMRESET			hard-reset the drive
	
		usage:
	
		  ioctl(fd, CDROMRESET, 0);
	
		inputs:		none
	
		outputs:	none
	
		error return:
		  EACCES	Access denied:  requires CAP_SYS_ADMIN
		  ENOSYS	Drive is not capable of resetting.
	
	
	
	
	CDROMREADCOOKED			read data in cooked mode
	
		usage:
	
		  u8 buffer[CD_FRAMESIZE]
		  ioctl(fd, CDROMREADCOOKED, buffer);
	
		inputs:		none
	
		outputs:
		  2048 bytes of data, "cooked" mode.
	
		notes:
		  Not implemented on all drives.
	
	
	
	
	CDROMREADALL			read all 2646 bytes
	
		Same as CDROMREADCOOKED, but reads 2646 bytes.
	
	
	
	CDROMSEEK			seek msf address
	
		usage:
	
		  struct cdrom_msf msf;
		  ioctl(fd, CDROMSEEK, &msf);
	
		inputs:
		  MSF address to seek to.
	
		outputs:	none
	
	
	
	CDROMPLAYBLK			scsi-cd only, (struct cdrom_blk)
	
		usage:
	
		  struct cdrom_blk blk;
		  ioctl(fd, CDROMPLAYBLK, &blk);
	
		inputs:
		  Region to play
	
		outputs:	none
	
	
	
	CDROMGETSPINDOWN
	
		usage:
	
		  char spindown;
		  ioctl(fd, CDROMGETSPINDOWN, &spindown);
	
		inputs:		none
	
		outputs:
		  The value of the current 4-bit spindown value.
	
	
	
	
	CDROMSETSPINDOWN
	
		usage:
	
		  char spindown
		  ioctl(fd, CDROMSETSPINDOWN, &spindown);
	
		inputs:
		  4-bit value used to control spindown (TODO: more detail here)
	
		outputs:	none
	
	
	
	
	
	CDROM_SET_OPTIONS		Set behavior options
	
		usage:
	
		  int options;
		  ioctl(fd, CDROM_SET_OPTIONS, options);
	
		inputs:
		  New values for drive options.  The logical 'or' of:
		    CDO_AUTO_CLOSE	close tray on first open(2)
		    CDO_AUTO_EJECT	open tray on last release
		    CDO_USE_FFLAGS	use O_NONBLOCK information on open
		    CDO_LOCK		lock tray on open files
		    CDO_CHECK_TYPE	check type on open for data
	
		outputs:
		  Returns the resulting options settings in the
		  ioctl return value.  Returns -1 on error.
	
		error return:
		  ENOSYS	selected option(s) not supported by drive.
	
	
	
	
	CDROM_CLEAR_OPTIONS		Clear behavior options
	
		Same as CDROM_SET_OPTIONS, except that selected options are
		turned off.
	
	
	
	CDROM_SELECT_SPEED		Set the CD-ROM speed
	
		usage:
	
		  int speed;
		  ioctl(fd, CDROM_SELECT_SPEED, speed);
	
		inputs:
		  New drive speed.
	
		outputs:	none
	
		error return:
		  ENOSYS	speed selection not supported by drive.
	
	
	
	CDROM_SELECT_DISC		Select disc (for juke-boxes)
	
		usage:
	
		  int disk;
		  ioctl(fd, CDROM_SELECT_DISC, disk);
	
		inputs:
		  Disk to load into drive.
	
		outputs:	none
	
		error return:
		  EINVAL	Disk number beyond capacity of drive
	
	
	
	CDROM_MEDIA_CHANGED		Check is media changed
	
		usage:
	
		  int slot;
		  ioctl(fd, CDROM_MEDIA_CHANGED, slot);
	
		inputs:
		  Slot number to be tested, always zero except for jukeboxes.
		  May also be special values CDSL_NONE or CDSL_CURRENT
	
		outputs:
		  Ioctl return value is 0 or 1 depending on whether the media
		  has been changed, or -1 on error.
	
		error returns:
		  ENOSYS	Drive can't detect media change
		  EINVAL	Slot number beyond capacity of drive
		  ENOMEM	Out of memory
	
	
	
	CDROM_DRIVE_STATUS		Get tray position, etc.
	
		usage:
	
		  int slot;
		  ioctl(fd, CDROM_DRIVE_STATUS, slot);
	
		inputs:
		  Slot number to be tested, always zero except for jukeboxes.
		  May also be special values CDSL_NONE or CDSL_CURRENT
	
		outputs:
		  Ioctl return value will be one of the following values
		  from <linux/cdrom.h>:
	
		    CDS_NO_INFO		Information not available.
		    CDS_NO_DISC
		    CDS_TRAY_OPEN
		    CDS_DRIVE_NOT_READY
		    CDS_DISC_OK
		    -1			error
	
		error returns:
		  ENOSYS	Drive can't detect drive status
		  EINVAL	Slot number beyond capacity of drive
		  ENOMEM	Out of memory
	
	
	
	
	CDROM_DISC_STATUS		Get disc type, etc.
	
		usage:
	
		  ioctl(fd, CDROM_DISC_STATUS, 0);
	
		inputs:		none
	
		outputs:
		  Ioctl return value will be one of the following values
		  from <linux/cdrom.h>:
		    CDS_NO_INFO
		    CDS_AUDIO
		    CDS_MIXED
		    CDS_XA_2_2
		    CDS_XA_2_1
		    CDS_DATA_1
	
		error returns:	none at present
	
		notes:
		  Source code comments state:
	
		    Ok, this is where problems start.  The current interface for
		    the CDROM_DISC_STATUS ioctl is flawed.  It makes the false
		    assumption that CDs are all CDS_DATA_1 or all CDS_AUDIO, etc.
		    Unfortunately, while this is often the case, it is also
		    very common for CDs to have some tracks with data, and some
		    tracks with audio.	Just because I feel like it, I declare
		    the following to be the best way to cope.  If the CD has
		    ANY data tracks on it, it will be returned as a data CD.
		    If it has any XA tracks, I will return it as that.	Now I
		    could simplify this interface by combining these returns with
		    the above, but this more clearly demonstrates the problem
		    with the current interface.  Too bad this wasn't designed
		    to use bitmasks...	       -Erik
	
		    Well, now we have the option CDS_MIXED: a mixed-type CD.
		    User level programmers might feel the ioctl is not very
		    useful.
				---david
	
	
	
	
	CDROM_CHANGER_NSLOTS		Get number of slots
	
		usage:
	
		  ioctl(fd, CDROM_CHANGER_NSLOTS, 0);
	
		inputs:		none
	
		outputs:
		  The ioctl return value will be the number of slots in a
		  CD changer.  Typically 1 for non-multi-disk devices.
	
		error returns:	none
	
	
	
	CDROM_LOCKDOOR			lock or unlock door
	
		usage:
	
		  int lock;
		  ioctl(fd, CDROM_LOCKDOOR, lock);
	
		inputs:
		  Door lock flag, 1=lock, 0=unlock
	
		outputs:	none
	
		error returns:
		  EDRIVE_CANT_DO_THIS	Door lock function not supported.
		  EBUSY			Attempt to unlock when multiple users
		  			have the drive open and not CAP_SYS_ADMIN
	
		notes:
		  As of 2.6.8.1, the lock flag is a global lock, meaning that
		  all CD drives will be locked or unlocked together.  This is
		  probably a bug.
	
		  The EDRIVE_CANT_DO_THIS value is defined in <linux/cdrom.h>
		  and is currently (2.6.8.1) the same as EOPNOTSUPP
	
	
	
	CDROM_DEBUG			Turn debug messages on/off
	
		usage:
	
		  int debug;
		  ioctl(fd, CDROM_DEBUG, debug);
	
		inputs:
		  Cdrom debug flag, 0=disable, 1=enable
	
		outputs:
		  The ioctl return value will be the new debug flag.
	
		error return:
		  EACCES	Access denied:  requires CAP_SYS_ADMIN
	
	
	
	CDROM_GET_CAPABILITY		get capabilities
	
		usage:
	
		  ioctl(fd, CDROM_GET_CAPABILITY, 0);
	
		inputs:		none
	
		outputs:
		  The ioctl return value is the current device capability
		  flags.  See CDC_CLOSE_TRAY, CDC_OPEN_TRAY, etc.
	
	
	
	CDROMAUDIOBUFSIZ		set the audio buffer size
	
		usage:
	
		  int arg;
		  ioctl(fd, CDROMAUDIOBUFSIZ, val);
	
		inputs:
		  New audio buffer size
	
		outputs:
		  The ioctl return value is the new audio buffer size, or -1
		  on error.
	
		error return:
		  ENOSYS	Not supported by this driver.
	
		notes:
		  Not supported by all drivers.
	
	
	
	DVD_READ_STRUCT			Read structure
	
		usage:
	
		  dvd_struct s;
		  ioctl(fd, DVD_READ_STRUCT, &s);
	
		inputs:
		  dvd_struct structure, containing:
		    type		specifies the information desired, one of
		    			DVD_STRUCT_PHYSICAL, DVD_STRUCT_COPYRIGHT,
					DVD_STRUCT_DISCKEY, DVD_STRUCT_BCA,
					DVD_STRUCT_MANUFACT
		    physical.layer_num	desired layer, indexed from 0
		    copyright.layer_num	desired layer, indexed from 0
		    disckey.agid
	
		outputs:
		  dvd_struct structure, containing:
		    physical		for type == DVD_STRUCT_PHYSICAL
		    copyright		for type == DVD_STRUCT_COPYRIGHT
		    disckey.value	for type == DVD_STRUCT_DISCKEY
		    bca.{len,value}	for type == DVD_STRUCT_BCA
		    manufact.{len,valu}	for type == DVD_STRUCT_MANUFACT
	
		error returns:
		  EINVAL	physical.layer_num exceeds number of layers
		  EIO		Received invalid response from drive
	
	
	
	DVD_WRITE_STRUCT		Write structure
	
		Not implemented, as of 2.6.8.1
	
	
	
	DVD_AUTH			Authentication
	
		usage:
	
		  dvd_authinfo ai;
		  ioctl(fd, DVD_AUTH, &ai);
	
		inputs:
		  dvd_authinfo structure.  See <linux/cdrom.h>
	
		outputs:
		  dvd_authinfo structure.
	
		error return:
		  ENOTTY	ai.type not recognized.
	
	
	
	CDROM_SEND_PACKET		send a packet to the drive
	
		usage:
	
		  struct cdrom_generic_command cgc;
		  ioctl(fd, CDROM_SEND_PACKET, &cgc);
	
		inputs:
		  cdrom_generic_command structure containing the packet to send.
	
		outputs:	none
		  cdrom_generic_command structure containing results.
	
		error return:
		  EIO		command failed.
		  EPERM		Operation not permitted, either because a
				write command was attempted on a drive which
				is opened read-only, or because the command
				requires CAP_SYS_RAWIO
		  EINVAL	cgc.data_direction not set
	
	
	
	CDROM_NEXT_WRITABLE		get next writable block
	
		usage:
	
		  long next;
		  ioctl(fd, CDROM_NEXT_WRITABLE, &next);
	
		inputs:		none
	
		outputs:
		  The next writable block.
	
		notes:
		  If the device does not support this ioctl directly, the
		  ioctl will return CDROM_LAST_WRITTEN + 7.
	
	
	
	CDROM_LAST_WRITTEN		get last block written on disc
	
		usage:
	
		  long last;
		  ioctl(fd, CDROM_LAST_WRITTEN, &last);
	
		inputs:		none
	
		outputs:
		  The last block written on disc
	
		notes:
		  If the device does not support this ioctl directly, the
		  result is derived from the disc's table of contents.  If the
		  table of contents can't be read, this ioctl returns an
		  error.

• [ ioctl ]
• 00-INDEX
• botching-up-ioctls.txt
• cdrom.txt
• hdio.txt
• ioctl-decoding.txt
• ioctl-number.txt
•  

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