udfinfo(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXIT STATUS | OUTPUT FORMAT | LIMITATIONS | AUTHOR | AVAILABILITY | SEE ALSO | COLOPHON

UDFINFO(1)               General Commands Manual              UDFINFO(1)

NAME         top

       udfinfo — show information about UDF filesystem

SYNOPSIS         top

       udfinfo [ options ] device

DESCRIPTION         top

       udfinfo shows various information about a UDF filesystem stored
       either on the block device or in the disk file image. The output
       from the udfinfo is suitable for parsing by external applications
       or scripts.

OPTIONS         top

       -h,--help
              Display the usage and the list of options.

       -b,--blocksize= block-size
              Specify the size of blocks in bytes. Valid block size for
              a UDF filesystem is a power of two in the range from 512
              to 32768 and must match a device logical (sector) size. If
              omitted, udfinfo tries to autodetect block size. First it
              tries logical (sector) size and then all valid block
              sizes.

       --startblock= start-block
              Specify the block location where the UDF filesystem
              starts. It is used for calculating the block location of
              the Volume Recognition Sequence (32 kB after the start
              block) and the first Anchor Volume Descriptor Pointer (256
              blocks after the start block).

              Normally start block is 0, but for Multisession UDF
              optical discs it is the block location where the last
              session of Multisession UDF disc starts.

              If omitted, udfinfo for optical disc tries to detect start
              block of the last session from disc Table Of Contents.
              Otherwise value 0 is used.

              For accessing some previous session of Multisession UDF
              optical disc, it is required to specify correct block
              where that previous session starts. And also to specify
              where that session ends via --lastblock option.

              For Multisession UDF disc images stored in file there is
              no way to detect where the last session starts and
              therefore it is necessary to specify the correct start
              block location manually from the original optical disc
              Table Of Contents.

              (Option available since udfinfo 2.3)

       --lastblock= last-block
              Specify the block location where the UDF filesystem ends.
              It is used for calculating the block location of second
              and third Anchor Volume Descriptor Pointer (256 blocks
              prior the last block and the last block itself).

              Normally last block is number of disk blocks minus one,
              but for Multisession UDF optical discs when reading
              different session than the last one (specified by
              --startblock) it is the block location where the specified
              session ends.

              If omitted, udfinfo for optical disc tried to detect the
              last recorded block with fallback to the last block of
              device or disk file image.

              For accessing some previous session of Multisession UDF
              optical disc, it is required to specify correct value for
              both --startblock and --lastblock options.

              (Option available since udfinfo 2.3)

       --vatblock= vat-block
              Specify the block location of the Virtual Allocation
              Table. Virtual Allocation Table is present only on UDF
              disks with Virtual Partition Map and must be at the last
              written/recorded disk block.

              If omitted, udfinfo for optical disc tries to detect the
              last recorded block with fallback to the last block of
              block device or disk file image or block specified by
              --lastblock. In most cases, this fallback does not have to
              work and for disk file images with Virtual Allocation
              Table it is necessary to specify the correct location.

              Virtual Allocation Table contains locations of UDF disk
              blocks needed to read data storage, determinate used and
              free space blocks, read File Set Identifier and calculate
              Windows-specific Volume Serial Number. Also, it contains
              Logical Volume Identifier and overwrite previously stored
              in Logical Volume Descriptor.

       --locale
              Encode UDF string identifiers on output according to
              current locale settings (default).

       --u8   Encode UDF string identifiers on output to 8-bit OSTA
              Compressed Unicode format without leading Compression ID
              byte, which is equivalent to Latin1 (ISO-8859-1) encoding.
              This will work only for strings which all Unicode code
              points are below U+100.

       --u16  Encode UDF string identifiers on output to 16-bit OSTA
              Compressed Unicode format without leading Compression ID
              byte, which is equivalent to UTF-16BE.

       --utf8 Encode UDF string identifiers on output to UTF-8.

EXIT STATUS         top

       udfinfo returns 0 if successful, non-zero if there are problems
       like a block device does not contain UDF filesystem.

OUTPUT FORMAT         top

       First part of the udfinfo standard output contains information in
       key=value format. List of all keys with their meaning are in the
       following table:

              filename
                     File name of the selected block device or disk file
                     image

              label  label is an alias for lvid, see udflabel(8) section
                     UDF LABEL AND UUID

              uuid   UUID are first 16 hexadecimal lowercase digits of
                     fullvsid, but see udflabel(8) section UDF LABEL AND
                     UUID

              lvid   UDF Logical Volume Identifier stored in UDF Logical
                     Volume Descriptor

              vid    UDF Volume Identifier stored in UDF Primary Volume
                     Descriptor

              vsid   fullvsid after uuid part, typically 17.–127.
                     character

              fsid   UDF File Set Identifier stored in UDF File Set
                     Descriptor

              fullvsid
                     UDF Volume Set Identifier stored in UDF Primary
                     Volume Descriptor

              owner  UDF Logical Volume Info1 stored in UDF
                     Implementation Use Volume Descriptor, represents
                     Owner name, person creating the medium or
                     filesystem (available since udfinfo 2.3)

              organization
                     UDF Logical Volume Info2 stored in UDF
                     Implementation Use Volume Descriptor, represents
                     Organization name responsible for creating the
                     medium or filesystem (available since udfinfo 2.3)

              contact
                     UDF Logical Volume Info3 stored in UDF
                     Implementation Use Volume Descriptor, represents
                     Contact information for the medium or filesystem
                     (available since udfinfo 2.3)

              appid  UDF Application Identifier stored in UDF Primary
                     Volume Descriptor, identifies application that
                     created medium or filesystem (available since
                     udfinfo 2.3)

              impid  UDF Developer Identifier stored in UDF
                     Implementation Identifier of UDF Primary Volume
                     Descriptor, uniquely identifies the implementation
                     which created medium or filesystem (available since
                     udfinfo 2.3)

              winserialnum
                     Windows-specific Volume Serial Number

              blocksize
                     UDF block size

              blocks Number of all blocks on the selected block device
                     or disk file image

              usedblocks
                     Number of used space blocks on UDF disk for data
                     storage

              freeblocks
                     Number of free space blocks on UDF disk for data
                     storage

              behindblocks
                     Number of blocks which are behind the last block
                     used by UDF disk

              numfiles
                     Number of stored files on UDF disk

              numdirs
                     Number of stored directories on UDF disk

              udfrev UDF revision needed for reading UDF disk

              udfwriterev
                     UDF revision needed for writing or modifying UDF
                     disk

              startblock
                     Block location where the UDF filesystem starts
                     (visible only when non-zero, available since
                     udfinfo 2.3)

              lastblock
                     Block location where the UDF filesystem ends
                     (visible only when it is not same as the last block
                     on disk, available since udfinfo 2.3)

              vatblock
                     Block location of the UDF Virtual Allocation Table
                     (visible only when available)

              integrity
                     UDF integrity of Logical Volume, one of: opened,
                     closed, unknown

              accesstype
                     UDF Access Type, one of: overwritable, rewritable,
                     writeonce, readonly, pseudo-overwritable, unknown

              softwriteprotect
                     Status of UDF SoftWriteProtect flag, either yes or
                     no (available since udfinfo 2.2)

              hardwriteprotect
                     Status of UDF HardWriteProtect flag, either yes or
                     no (available since udfinfo 2.2)

       When UDF integrity is not closed it means that the UDF disk was
       not properly unmounted, is in an inconsistent state and needs
       repairing.

       When either softwriteprotect or hardwriteprotect flag is set then
       UDF disk should be treated as read-only.

       All UDF string identifiers are stored on UDF disk in Unicode,
       therefore they are locale or code page agnostic. Options
       --locale, --u8, --u16 and --utf8 controls how are identifiers
       encoded on output.

       All newline characters from the UDF string identifiers are
       removed, so it is guaranteed that the newline character is
       present only as a separator.

       Second part of the udfinfo standard output contains list of UDF
       block types stored on device, one per line in the following
       format:

              start=block-num, blocks=block-count, type=block-type

       With meaning that block-type starts at UDF block block-num and
       span block-count blocks on device.

       Windows-specific Volume Serial Number is a non-standard 32-bit
       checksum, calculated as four separate 8-bit XOR checksums of 512
       bytes long UDF File Set Descriptor. Therefore, it cannot be set
       or changed as opposed to UUID which is 64-bit long. This non-
       standard checksum is used only by Windows systems (since Windows
       98 era when it was introduced) and can be displayed on Windows
       systems by applications like vol, dir or fsutil.exe.

LIMITATIONS         top

       udfinfo prior to version 2.3 was unable to handle Multisession
       UDF discs correctly. It always printed only information about the
       first session (the oldest one) and not about the last session
       (the most recent).

       udfinfo prior to version 2.2 was unable to print Unicode strings
       with code points above U+FFFF correctly.

       udfinfo prior to version 2.2 was unable to read Metadata
       Partition. Therefore, determining used and free space blocks,
       reading File Set Identifier and calculating Windows-specific
       Volume Serial Number did not have to be available or correctly
       calculated for disks with UDF revisions higher than 2.01 which
       had Metadata Partition.

       udfinfo prior to version 2.1 was unable to read Virtual
       Allocation Table stored outside of Information Control Block.
       Therefore above limitation applied also for some Write Once
       media.

AUTHOR         top

       Pali Rohár <pali.rohar@gmail.com>

AVAILABILITY         top

       udfinfo is part of the udftools package since version 2.0 and is
       available from https://github.com/pali/udftools/.

SEE ALSO         top

       mkudffs(8), pktsetup(8), udflabel(8), cdrwtool(1), wrudf(1)

COLOPHON         top

       This page is part of the udftools (Linux tools for UDF
       filesystems and DVD/CD-R(W) drives) project.  Information about
       the project can be found at ⟨https://github.com/pali/udftools⟩.
       If you have a bug report for this manual page, see
       ⟨https://github.com/pali/udftools/issues⟩.  This page was
       obtained from the project's upstream Git repository
       ⟨https://github.com/pali/udftools.git⟩ on 2021-08-27.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2021-08-14.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

Commands                        udftools                      UDFINFO(1)

Pages that refer to this page: mkudffs(8)udflabel(8)