1UDFINFO(1) General Commands Manual UDFINFO(1)
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6 udfinfo — show information about UDF filesystem
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10 udfinfo [ options ] device
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14 udfinfo shows various information about a UDF filesystem stored either
15 on the block device or in the disk file image. The output from the
16 udfinfo is suitable for parsing by external applications or scripts.
17
20 -h,--help
21 Display the usage and the list of options.
22 -b,--blocksize= block-size
25 Specify the size of blocks in bytes. Valid block size for a UDF
26 filesystem is a power of two in the range from 512 to 32768 and
27 must match a device logical (sector) size. If omitted, udfinfo
28 tries to autodetect block size. First it tries logical (sector)
29 size and then all valid block sizes.
30 --startblock= start-block
33 Specify the block location where the UDF filesystem starts. It
34 is used for calculating the block location of the Volume Recog‐
35 nition Sequence (32 kB after the start block) and the first An‐
36 chor Volume Descriptor Pointer (256 blocks after the start
37 block).
38 Normally start block is 0, but for Multisession UDF optical
40 discs it is the block location where the last session of Multi‐
41 session UDF disc starts.
42 If omitted, udfinfo for optical disc tries to detect start block
44 of the last session from disc Table Of Contents. Otherwise value
45 0 is used.
46 For accessing some previous session of Multisession UDF optical
48 disc, it is required to specify correct block where that previ‐
49 ous session starts. And also to specify where that session ends
50 via --lastblock option.
51 For Multisession UDF disc images stored in file there is no way
53 to detect where the last session starts and therefore it is nec‐
54 essary to specify the correct start block location manually from
55 the original optical disc Table Of Contents.
56 (Option available since udfinfo 2.3)
58 --lastblock= last-block
61 Specify the block location where the UDF filesystem ends. It is
62 used for calculating the block location of second and third An‐
63 chor Volume Descriptor Pointer (256 blocks prior the last block
64 and the last block itself).
65 Normally last block is number of disk blocks minus one, but for
67 Multisession UDF optical discs when reading different session
68 than the last one (specified by --startblock) it is the block
69 location where the specified session ends.
70 If omitted, udfinfo for optical disc tried to detect the last
72 recorded block with fallback to the last block of device or disk
73 file image.
74 For accessing some previous session of Multisession UDF optical
76 disc, it is required to specify correct value for both --start‐
77 block and --lastblock options.
78 (Option available since udfinfo 2.3)
80 --vatblock= vat-block
83 Specify the block location of the Virtual Allocation Table. Vir‐
84 tual Allocation Table is present only on UDF disks with Virtual
85 Partition Map and must be at the last written/recorded disk
86 block.
87 If omitted, udfinfo for optical disc tries to detect the last
89 recorded block with fallback to the last block of block device
90 or disk file image or block specified by --lastblock. In most
91 cases, this fallback does not have to work and for disk file im‐
92 ages with Virtual Allocation Table it is necessary to specify
93 the correct location.
94 Virtual Allocation Table contains locations of UDF disk blocks
96 needed to read data storage, determinate used and free space
97 blocks, read File Set Identifier and calculate Windows-specific
98 Volume Serial Number. Also, it contains Logical Volume Identi‐
99 fier and overwrite previously stored in Logical Volume Descrip‐
100 tor.
101 --locale
104 Encode UDF string identifiers on output according to current lo‐
105 cale settings (default).
106 --u8 Encode UDF string identifiers on output to 8-bit OSTA Compressed
109 Unicode format without leading Compression ID byte, which is
110 equivalent to Latin1 (ISO-8859-1) encoding. This will work only
111 for strings which all Unicode code points are below U+100.
112 --u16 Encode UDF string identifiers on output to 16-bit OSTA Com‐
115 pressed Unicode format without leading Compression ID byte,
116 which is equivalent to UTF-16BE.
117 --utf8 Encode UDF string identifiers on output to UTF-8.
120
123 udfinfo returns 0 if successful, non-zero if there are problems like a
124 block device does not contain UDF filesystem.
125
128 First part of the udfinfo standard output contains information in
129 key=value format. List of all keys with their meaning are in the fol‐
130 lowing table:
131 filename File name of the selected block device or disk
134 file image
135 label label is an alias for lvid, see udflabel(8)
137 section UDF LABEL AND UUID
138 uuid UUID are first 16 hexadecimal lowercase digits
140 of fullvsid, but see udflabel(8) section UDF
141 LABEL AND UUID
142 lvid UDF Logical Volume Identifier stored in UDF
144 Logical Volume Descriptor
145 vid UDF Volume Identifier stored in UDF Primary
147 Volume Descriptor
148 vsid fullvsid after uuid part, typically 17.–127.
150 character
151 fsid UDF File Set Identifier stored in UDF File Set
153 Descriptor
154 fullvsid UDF Volume Set Identifier stored in UDF Primary
156 Volume Descriptor
157 owner UDF Logical Volume Info1 stored in UDF Imple‐
159 mentation Use Volume Descriptor, represents
160 Owner name, person creating the medium or
161 filesystem (available since udfinfo 2.3)
162 organization UDF Logical Volume Info2 stored in UDF Imple‐
164 mentation Use Volume Descriptor, represents Or‐
165 ganization name responsible for creating the
166 medium or filesystem (available since udfinfo
167 2.3)
168 contact UDF Logical Volume Info3 stored in UDF Imple‐
170 mentation Use Volume Descriptor, represents
171 Contact information for the medium or filesys‐
172 tem (available since udfinfo 2.3)
173 appid UDF Application Identifier stored in UDF Pri‐
175 mary Volume Descriptor, identifies application
176 that created medium or filesystem (available
177 since udfinfo 2.3)
178 impid UDF Developer Identifier stored in UDF Imple‐
180 mentation Identifier of UDF Primary Volume De‐
181 scriptor, uniquely identifies the implementa‐
182 tion which created medium or filesystem (avail‐
183 able since udfinfo 2.3)
184 winserialnum Windows-specific Volume Serial Number
186 blocksize UDF block size
188 blocks Number of all blocks on the selected block de‐
190 vice or disk file image
191 usedblocks Number of used space blocks on UDF disk for
193 data storage
194 freeblocks Number of free space blocks on UDF disk for
196 data storage
197 behindblocks Number of blocks which are behind the last
199 block used by UDF disk
200 numfiles Number of stored files on UDF disk
202 numdirs Number of stored directories on UDF disk
204 udfrev UDF revision needed for reading UDF disk
206 udfwriterev UDF revision needed for writing or modifying
208 UDF disk
209 startblock Block location where the UDF filesystem starts
211 (visible only when non-zero, available since
212 udfinfo 2.3)
213 lastblock Block location where the UDF filesystem ends
215 (visible only when it is not same as the last
216 block on disk, available since udfinfo 2.3)
217 vatblock Block location of the UDF Virtual Allocation
219 Table (visible only when available)
220 integrity UDF integrity of Logical Volume, one of:
222 opened, closed, unknown
223 accesstype UDF Access Type, one of: overwritable,
225 rewritable, writeonce, readonly, pseudo-over‐
226 writable, unknown
227 softwriteprotect Status of UDF SoftWriteProtect flag, either yes
229 or no (available since udfinfo 2.2)
230 hardwriteprotect Status of UDF HardWriteProtect flag, either yes
232 or no (available since udfinfo 2.2)
233 When UDF integrity is not closed it means that the UDF disk was not
235 properly unmounted, is in an inconsistent state and needs repairing.
236 When either softwriteprotect or hardwriteprotect flag is set then UDF
238 disk should be treated as read-only.
239 All UDF string identifiers are stored on UDF disk in Unicode, therefore
241 they are locale or code page agnostic. Options --locale, --u8, --u16
242 and --utf8 controls how are identifiers encoded on output.
243 All newline characters from the UDF string identifiers are removed, so
245 it is guaranteed that the newline character is present only as a sepa‐
246 rator.
247 Second part of the udfinfo standard output contains list of UDF block
249 types stored on device, one per line in the following format:
250 start=block-num, blocks=block-count, type=block-type
252 With meaning that block-type starts at UDF block block-num and span
254 block-count blocks on device.
255 Windows-specific Volume Serial Number is a non-standard 32-bit check‐
257 sum, calculated as four separate 8-bit XOR checksums of 512 bytes long
258 UDF File Set Descriptor. Therefore, it cannot be set or changed as op‐
259 posed to UUID which is 64-bit long. This non-standard checksum is used
260 only by Windows systems (since Windows 98 era when it was introduced)
261 and can be displayed on Windows systems by applications like vol, dir
262 or fsutil.exe.
263
266 udfinfo prior to version 2.3 was unable to handle Multisession UDF
267 discs correctly. It always printed only information about the first
268 session (the oldest one) and not about the last session (the most re‐
269 cent).
270 udfinfo prior to version 2.2 was unable to print Unicode strings with
272 code points above U+FFFF correctly.
273 udfinfo prior to version 2.2 was unable to read Metadata Partition.
275 Therefore, determining used and free space blocks, reading File Set
276 Identifier and calculating Windows-specific Volume Serial Number did
277 not have to be available or correctly calculated for disks with UDF re‐
278 visions higher than 2.01 which had Metadata Partition.
279 udfinfo prior to version 2.1 was unable to read Virtual Allocation Ta‐
281 ble stored outside of Information Control Block. Therefore above limi‐
282 tation applied also for some Write Once media.
283
286 Pali Rohár <pali.rohar@gmail.com>
287
290 udfinfo is part of the udftools package since version 2.0 and is avail‐
291 able from https://github.com/pali/udftools/.
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295 mkudffs(8), pktsetup(8), udflabel(8), cdrwtool(1), wrudf(1)
296Commands udftools UDFINFO(1)