MAN page from RedHat EL 8 xorriso1-1.5.4-2.el8.x86_64.rpm


Section: User Commands (1)
Updated: Version 1.5.4, Jan 30, 2021


xorrisofs - Emulation of ISO 9660 program mkisofs by program xorriso 


xorrisofs[ options ] [-o filename ] pathspec [pathspecs ...]


xorrisofsproduces Rock Ridge enhanced ISO 9660 filesystems and add-on sessions tosuch filesystems. Optionally it can produce Joliet directory trees too.

xorrisofs understands options of program mkisofs from cdrtools byJoerg Schilling.Its implementation is part of program xorriso which shares no sourcecode with cdrtools. 

ISO 9660, Rock Ridge, Joliet, HFS+:

ISO 9660(aka ECMA-119) is a read-only filesystem that is mainly used foroptical media CD, DVD, BD, but may also reside on other storage devices likedisk files, USB sticks or disk partitions. It is widely readable by manyoperating systems and by boot facilities of personal computers.
ISO 9660 describes directories and data files byvery restricted filenames with no distinction of upper case and lower case. Its metadata do not comply to fundamental POSIX specifications.
Rock Ridgeis the name of a set of additional information which enhancean ISO 9660 filesystem so that it can represent a POSIX compliant filesystemwith ownership, access permissions, symbolic links, and other attributes.Rock Ridge allows filenames of up to 255 bytes and paths of up to1024 bytes.
xorrisofs produces Rock Ridge information by default. It is stronglydiscouraged to disable this feature.
Joliet is the name of an additional directory tree which providesfilenames up to 64 characters encoded as UTF-16.A Joliet tree is mainly interesting for reading the ISO image byoperating systems of Microsoft Corporation.Production of this directory tree may be enabled by option -J.
ISO 9660:1999is the name of an additional directory tree which provides longerfilenames. It allows single file names to have up to 207 characters.It might be of use with some older computer system bootfacilities which read neither Rock Ridge nor Joliet butneed longer filenames nevertheless.Production of this directory tree may be enabled by option -iso-level 4.
HFS+is the name of a filesystem which is normally used for writing and readingon hard disks and similar devices. It is possible to embed a HFS+ partitioninto the emerging ISO 9660 image and to mark it by Apple Partition Mapentries. This interferes with options which copy data into the first 32 KiBof the ISO image, like -G or -isohybrid-mbr. See option -hfsplus.
The main purpose for having an embedded HFS+ partition is booting ofcertain models of Apple computers. 

Inserting files into the ISO image:

xorrisofs deals with two kinds of file addresses:
disk_pathis a path to an object in the local filesystem tree.
iso_rr_pathis the Rock Ridge address of a file object in the ISO image. If no Rock Ridge information shall be stored in an emerging ISO, then thenames will get mapped to ISO 9660 names of limited length and character set.

A program argument is handled as a pathspec, if it is notrecognized as original mkisofs option or additional xorrisofs option.A pathspec depicts an input file object by a disk_path. If option -graft-points is not present, then the behavior depends on thefile type of disk_path. Directories get merged with the /-directory of theISO image. Files of other types get copied into the /-directory.
If -graft-points is present then each pathspec gets split at the firstoccurrence of the =-character.The part before the = is taken as target, i.e. the iso_rr_path forthe file object in the ISO image. The part after the first = is takenas source, i.e. the disk_path of the input object.
It is possible to make =-characters part of the iso_rr_path by precedingthem with a \-character. The same must be done for \-characters whichshall be part of the iso_rr_path.

If the source part of the pathspec leads to a directory, then all filesunderneath this directory get inserted into the image, too.It is possible to exclude particular files from being insertedby help of option -m.
In case that target already exists, the following rules apply:Directories and other files may overwrite existing non-directories.Directories get merged with existing directories.Non-directories may not overwrite existing directories. 

Relation to program xorriso:

xorrisofs is actually a command mode of program xorriso,which gets entered either by xorriso command "-as mkisofs" or bystarting the program by one of the names "xorrisofs", "mkisofs","genisoimage", or "genisofs".
This command mode can be left by argument "--" which leadsto generic xorriso command mode. See man xorriso for its description.

xorriso performs image reading and writing by help of libburn, which ismainly intended for optical drives, but also operates on all POSIXfile types except directories.
The program messages call any image file a "drive". File types which are notsupported for reading are reported as "blank". The reported free mediaspace may be quite fictional.
Nevertheless xorrisofs does not operate directly on optical drives,but rather forces libburn to regard them as general device files.So for writing of sequential optical media (CD, DVD-R, DVD+R, BD-R)one will have to use a burn program. E.g the cdrecord emulation of xorriso.See EXAMPLES. 



Image loading:

The following options control loading of an existing ISO image for the purposeof preparing a suitable add-on session.If they are missing then a new image is composed from scratch.

-M disk_path
Set the path from which to load the existing ISO image directory treeon which to base the upcoming directory tree as add-on session.The path must lead to a random-access readable file object.On GNU/Linux: regular data files or block device files.
A special kind of pseudo disk_path has the form "/dev/fd/"number.It depicts the open file descriptor with the given number, regardless whetherthe operating system supports this feature by file nodes in /dev/fd or not.E.g. /dev/fd/3 is file descriptor 3 which was opened by the program thatlater started xorriso.
-prev-session disk_path
Alias of -M.
-dev disk_path
Alias of -M.
-C last_session_start,next_writeable_address
Set the 2 KiB block address last_session_start from where to read theISO image out of the file given by option -M.
Separated by a comma, set the next_writeable_address to which theadd-on session will finally be written. Decisive is actually the blockaddress which the intended readers will have to use as superblock addresson the intended medium.
Both values can be inquired from optical media by help of burn programsand cdrecord option -msinfo. xorriso itself can obtain it in itscdrecord emulation.

  values=$(xorriso -as cdrecord dev=/dev/... -msinfo)

  echo $values
Option -C may be used without option -M to create an ISO image fromscratch and prepare it for being finally written to a block addressother than 0. Parameter last_session_start must then be set to 0.
-cdrecord-params last_session_start,next_writeable_address
Alias of -C.
Settings for file insertion:
-path-list disk_path
Read pathspecs line-by-line from disk_file and insert the depicted fileobjects into the ISO image. If disk_path is "-" then read the pathspecsfrom standard input.
--quoted_path_list disk_path
Like option -path-list but reading quoted words rather than plain lines.Whitespace outside of quotes will be discarded. On the other hand it ispossible to represent pathspecs which contain newline characters.
The double quotation mark " and the single quotation mark ' can be used toenclose whitespace and make it part of pathspecs. Each marktype can enclose the marks of the other type. A trailing backslash \ outsidequotations or an open quotation cause the next input line to be appended.

Resolve symbolic links on disk rather than storing them as symboliclinks in the ISO image.
Alias of -f.
Enable interpretation of input file pathspecs as combination of iso_rr_pathand disk_path, separated by a =-character.
-m disk_pattern
Exclude files from being inserted into the image. Silently ignored arethose files of which the disk_path matches the given shell parser pattern.If no /-character is part of the pattern, then it gets matched againstthe leaf name of the disk file.
It is possible to give more than one -m option.
Alias of -m.

Alias of -m.
Alias of -m.
-exclude-list disk_path
Perform -m using each line out of file disk_path as argument disk_pattern.

Enable recognition and proper processing of zisofs compressed filesas produced by program mkzftree. These files will get equipped with thenecessary meta data so that a Linux kernel will recognize them anddeliver their content in uncompressed form.
Alias of -z.

Enable the recognition and proper processing of experimental zisofs version 2compressed files.The Linux kernel (as of 5.9) does not yet know this format and will complainlike

  isofs: Unknown ZF compression algorithm: PZ
This complaint can be prevented by option --zisofs2-susp-z2 .
The files will be shown by unaware kernels as they were submitted to xorriso,i.e. with zisofs2 header, block pointer list, and compressed data.
--zisofs-version-2 also enables -z.
Enable the production of SUSP entries "Z2" instead of "ZF" with zisofs2compressed files. Unaware Linux kernels silently ignore "Z2" entries.
Enable the production of SUSP entries "ZF" instead of "Z2" with zisofs2compressed files. Unaware Linux kernels complain about zisofs2 "ZF" by"Unknown ZF compression algorithm" and thus leave a mark in the system log.
-root iso_rr_path
Insert all files under the given iso_rr_path. If option -graft-points is given,then iso_rr_path is prepended to each target part of a pathspec.
The default for -root is "/".
-old-root iso_rr_path
Enable incremental insertion of files into the loaded image.The effective target and source addresses of given pathspecs get comparedwhether the target already exists in the ISO image and is still identicalto the source on disk. Metadata in the ISO image will get adjusted, if theydiffer from those on disk.New files and files with changed content will get newly added.Target files which do not exist in any of the according pathspec sourceswill get removed from the ISO directory tree.
If the effective setting of -root differs from the iso_rr_path givenwith -old-root, then the files underneath the -old-root directory get clonedunderneath the -root directory. Cloning happens before file comparison.
Disable recording and use of disk inode numbers.If no disk inode numbers are recorded, then option -old-root will haveto read disk file content and compare it with the MD5 checksum that isrecorded in the ISO image.
With recorded disk inode numbers and with credible ctime and mtime,it is possible to detect potential changes in the content without actuallyreading it.A loophole remains if multiple different filesystems may get mountedat the same directory, like it is habit with /mnt.In this case one has to use option --old-root-devnoor disable the inode number shortcut by --old-root-no-ino.
Enable comparison of recorded device numbers together with recordedinode numbers. This works only with good old stable device numbers whichget out of fashion, regrettably. If the hard disk has a differentdevice number after each reboot, then this comparison will see allfiles as changed and thus prevent any incremental size saving.
Disable recording and use of MD5 checksums for data file content.If neither checksums and nor disk inode numbers are recorded, thenoption -old-root will have to read ISO image file content when comparingit with disk file content.
Settings for image production:
-o disk_path
Set the output file address for the emerging ISO image.If the address exists as regular file, it will be truncated to length 0when image production begins. It may not already exist as directory.If it does not exist yet then its parent directory must exist anda regular file will get created.
A special kind of pseudo disk_path has the form "/dev/fd/"number.It depicts the open file descriptor with the given number, regardless whetherthe operating system supports this feature by file nodes in /dev/fd or not.E.g. /dev/fd/4 is file descriptor 4 which was opened by the program thatlater started xorriso.
Default is standard output (/dev/fd/1) which may also be set by disk_path "-".
-output disk_path
Alias of -o.
--stdio_sync "on"|"off"|"end"|number
Set the number of bytes after which to force output to diskin order to keep the memory from being clogged with lots ofpending data for slow devices. "on" is the same as "16m".Forced output can be disabled by "off", or be delayed by "end" until all data are produced. If a number is chosen, then it must be at least 64k.
The default with xorriso mkisofs emulation is --stdio_sync "off".
xorriso uses an inner fifo buffer with default size 4 MiB. So forcingthe operating system i/o cache to disk does not necessarily block thesimultaneous production of more image content.
Write a second superblock with the first session into random-accessfiles. If further sessions get appended and the first superblock gets updated,then the second superblock will not be overwritten. So it is still possible tomount the first session and to find the start blocks of the further sessions.
The price is 64 KiB extra space consumption. If -partition_offset is non-zero,then it is 128 KiB plus twice the partition setup.
Do not write a second superblock with the first session into random-accessfiles.
This is the default.
--sort-weight weight_number iso_rr_path
Attribute a LBA weight number to regular files. If iso_rr_path leadsto a directory then all regular files underneath will get the weight_number.
The weight_number may range from -2147483648 to 2147483647.The higher it is, the lower will be the block address of the file datain the emerging ISO image.Currently the El Torito boot catalog has a hardcoded weight of 1 billion.Normally it should occupy the block with the lowest possible address.Data files get added or loaded with initial weight 0. Boot image fileshave a default weight of 2.
--sort-weight-list disk_path
Read pairs of weight number and iso_rr_path from a file of thelocal filesystem. Apply each pair like with --sort-weight.
Only the last --sort-weight-list or--sort-weight-patterns of a xorrisofs run gets into effect.
The weight number is read from the start of the line.The iso_rr_path part of an input line begins immediately after the first blankor tab character of the line.
Notes for the case that this feature is used within a sequence of genericxorriso commands (not an issue with a pure mkisofs emulation run):
The addressed files must already be in the ISO image model when you execute

  -as mkisofs --sort-weight-list disk_path --
Several such commands may be used to apply more than one weight file.
Data files which are loaded by -indev or -dev get a weight between 1 and2 exp 28 = 268,435,456, depending on their block address. This shall keepthem roughly in the same order if the write method of modifying is applied.
--sort-weight-patterns disk_path
Like --sort-weight-list , but expanding the iso_rr_paths asshell parser patterns and applying --sort-weight to eachmatching file.
-uid number|name
Use the given number or locally existing user name as owner id of all filesand directories in the emerging filesystem.Empty name or name "-" revoke this feature.
-gid number|name
Use the given number or locally existing group name as group id of all filesand directories in the emerging filesystem.Empty name or name "-" revoke this feature.
-dir-mode mode
Set the access permissions for all directories in the image to the givenmode which is either an octal number beginning with "0" or a comma separatedlist of statements of the form [ugoa]*[+-=][rwxst]* . E.g. ug=rx,a-rwx
-file-mode mode
Like -dir-mode but for all regular data files in the image.

Add 300 KiB to the end of the produced ISO image. This circumvents possibleread errors from ISO images which have been written to CD media in TAO mode.The additional bytes are claimed as part of the ISO image if not --emul-tocis given.
Option -pad is the default.
Disable padding of 300 KiB to the end of the produced ISO image.This is safe if the image is not meant to be written on CD or if itgets written to CD as only track in write mode SAO.
Use the old way of of giving block addresses in the rangeof [0,31] to files with no own data content. The new way is to havea dedicated block to which all such files will point.
Settings for standards compliance:
-iso-level number
Specify the ISO 9660 version which defines the limitations of file namingand data file size. The naming restrictions do not apply to theRock Ridge names but only to the low-level ISO 9660 names.There are three conformance levels:
Level 1 allows ISO names of the form 8.3 and file size up to 4 GiB - 1.
Level 2 allows ISO names with up to 32 charactersand file size up to 4 GiB - 1.
Level 3 allows ISO names with up to 32 charactersand file size of up to 400 GiB - 200 KiB. (This size limitation isset by the xorriso implementation and not by ISO 9660 which wouldallow nearly 8 TiB.)
Pseudo-level 4 enables production of an additional ISO 9660:1999directory tree.
Do not follow a bad habit of mkisofs which allows dots in the ISO namesof directories. On the other hand, some bootable GNU/Linux images depend onthis bad habit.

This option allows ISO file names without dot and up to 37 characters,ISO file paths longer than 255 characters, and all ASCII characters in filenames. Further it omits the semicolon and the version numbers at the endof ISO names.
This all violates ISO 9660 specs.
Alias of -U.
-untranslated_name_len number
Allow ISO file names up to the given number of characterswithout any character conversion. The maximum number is 96.If a file name has more characters, then image production willfail deliberately.
This violates ISO 9660 specs.
Allow lowercase character in ISO file names.
This violates ISO 9660 specs.
Allow nearly all 7-bit characters in ISO file names.Not allowed are 0x0 and '/'. If not option -allow-lowercase is given,then lowercase letters get converted to uppercase.
This violates ISO 9660 specs.

Do not add trailing dot to ISO file names without dot.
This violates ISO 9660 specs.
Alias of -d.

Allow up to 31 characters in ISO file names.
Alias of -l.
Allow up to 37 characters in ISO file names.
This violates ISO 9660 specs.

Omit the semicolon and the version numbers at the end of ISO names.
This violates ISO 9660 specs.
Alias of -N.
Settings for standards extensions:

With mkisofs this option enables Rock Ridge extensions. xorrisofsproduces them by default. It is strongly discouraged to disable themby option --norock.

Alias of -R.

Enable Rock Ridge and set user and group id of all files in the ISO image to 0.Grant r-permissions to all. Deny all w-permissions.If any x-permission is set, grant x-permission to all.Remove s-bit and t-bit.
These attribute changes stay delayed until mkisofs emulation ends. Within thesame -as mkisofs emulation command they can be revoked by a subsequentoption --norock. For compatibility reasons, option -R does notrevoke the changes ordered by -r.
Alias of -r.

This option disables the production of Rock Ridge extensions for theISO 9660 file objects. The multi-session capabilities of xorrisofsdepend much on the naming fidelity of Rock Ridge. So it is stronglydiscouraged to disable it by this option, except for the special use caseto revoke the effect of -r by:
 --norock -R
--set_all_file_dates timestring
Set mtime, atime, and ctime of all files and directories to the given time.
Valid timestring formats are: 'Nov 8 14:51:13 CET 2007', 110814512007.13,2007110814511300. See also --modification-date= and man xorriso,Examples of input timestrings.
If the timestring is "set_to_mtime", then theatime and ctime of each file and directory get set to the value found in theirmtime.
These actions stay delayed until actual ISO production begins.Up to then they can be revoked by --set_all_file_dateswith empty timestring or timestring "default".
The timestamps of the El Torito boot catalog file get refreshed when the ISOis produced. They can be influenced by --modification-date=.
-file_name_limit number
Set the maximum permissible length for file names in the range of 64 to 255.Path components which are longer than the given number will get truncatedand have their last 33 bytes overwritten by a colon ':' and thehex representation of the MD5 of the first 4095 bytes of the wholeoversized name. Potential incomplete UTF-8 characters will get theirleading bytes replaced by '_'.
Linux kernels up to at least 4.1 misrepresent names of length 254 and 255.If you expect such names in or under disk_paths and plan to mount the ISOby such Linux kernels, consider to set -file_name_limit 253.
The standard ECMA-119 demands that no path in the image shall have morethan 8 name components or 255 characters. Therefore it would be necessaryto move deeper directory trees to a higher directory. Rock Ridge offers anopportunity to let these relocated directories appear at their originaldeep position, but this feature might not be implemented properly byoperating systems which mount the image.
Option -D disables this deep directory relocation, and thus violatesISO 9660 specs.
xorrisofs has -D set by default. If given explicitly then it overridesthe options -rr_reloc_dir and -hide-rr-moved.
Alias of -D.
-rr_reloc_dir name
Enable the relocation of deep directories and thus avoid ECMA-119 file pathsof more than 8 name components or 255 characters. Directories which lead tosuch file paths will get moved to a directory in the root directory of theimage. Its name gets set by this option.It is permissible to use the root directory itself.
The overall directory tree will appear originally deep when interpreted asRock Ridge tree. It will appear as re-arranged if only ECMA-119 informationis considered.
If the given relocation target directory does not already exist when imageproduction begins, then it will get created and marked for Rock Ridge asrelocation artefact. At least on GNU/Linux it will not be displayed inmounted Rock Ridge images.
The name must not contain a '/' character after its first character and itmust not be longer than 255 bytes.
This option has no effect if option -D is present.
Alias of -rr_reloc_dir "/.rr_moved"
Enable all options which improve backup fidelity:
--acl, --xattr-any, --md5,--hardlinks.
If you later restore a backup with xattr from non-user namespaces, then makesure that the target operating system and filesystem know what these attributesmean. Possibly you will need administrator privileges to record or restoresuch attributes. At recording time, xorriso will try to tolerate missingprivileges and just record what is readable.
Option -xattr after option -for_backup excludes non-user attributesfrom being recorded.

Enable recording and loading of ACLs from GNU/Linux or FreeBSD(see man getfacl, man acl). They will not be in effect with mounted ISO images. But xorriso canrestore them on the same systems when extracting files from the ISO image.

Enable recording and loading of GNU/Linux or FreeBSD extended attributes inuser namespace (see man getfattr and man attr,man getextattr and man 9 extattr, respectively).They will not be in effect with mounted ISO images. But xorriso canrestore them on the same systems when extracting files from the ISO image.

Enable recording and loading of GNU/Linux or FreeBSD extended attributes inall namespaces. This might need administrator privileges, even if the ownerof the disk file tries to read the attributes.

Enable recording of MD5 checksums for the overall ISO image and for eachsingle data file in the image. xorriso can check the content of an ISOimage with these sums and raise alert on mismatch.See man xorriso, options -check_media, check_md5_r.xorriso can print recorded MD5 checksums. E.g. by:

 -find / -exec get_md5
Enable loading and recording of hardlink relations.Search for families of iso_rr files which stem from the same disk file,have identical content filtering and have identical properties.The members of each family get the same inode number in the ISO image.
Whether these numbers are respected at mount time depends on the operatingsystem. xorriso can create hardlink families when extracting files fromthe ISO image.
--scdbackup_tag disk_path record_name
Append a scdbackup checksum record to the image. This works only if theparameter next_writeable_address of option -C is 0 and --md5 is enabled.If disk_path is not an empty string, then append a scdbackup checksum recordto the end of this file. record_name is a word that gets part of tagand record.
Program scdbackup_verify will recognize and verify tag and file record.
An empty record_name disables this feature.

Enable the production of an additional Joliet directory tree alongwith the ISO 9660 Rock Ridge tree.
Alias of -J.
Allow 103 characters in Joliet file names rather than 64 as is prescribedby the specification. Allow Joliet paths longer than the prescribed limit of240 characters.
Oversized names get truncated. Without this option, oversized paths getexcluded from the Joliet tree.
Encode Joliet file names in UTF-16BE rather than UCS-2.The difference is with characters which are not presentin UCS-2 and get encoded in UTF-16 by 2 words of 16 bit each.Both words then stem from a reserved subset of UCS-2.
Enable the production of an additional HFS+ filesystem inside the ISO 9660image and mark it by Apple Partition Map (APM) entries in the System Area,the first 32 KiB of the image.
This may collide with options like -G or -isohybrid-mbr which submit user datafor inclusion in the same address range.The first 8 bytes of the System Area get overwritten by{ 0x45, 0x52, 0x08 0x00, 0xeb, 0x02, 0xff, 0xff }which can be executed as x86 machine code without negative effects.So if an MBR gets combined with this feature, then its first 8 bytesshould contain no essential commands.
The next blocks of 2 KiB in the System Area will be occupied by APM entries.The first one covers the part of the ISO image before the HFS+ filesystemmetadata. The second one marks the range from HFS+ metadata to the endof file content data. If more ISO image data follow, then a third partitionentry gets produced. Other features of xorriso might cause the need formore APM entries.
Be aware that HFS+ is case-insensitive although it can record file nameswith upper-case and lower-case letters. Therefore, file names from the iso_rrname tree may collide in the HFS+ name tree. In this case they get changedby adding underscore characters and counting numbers. In case of very longnames, it might be necessary to map them to "MANGLED_...".
The HFS+ implementation in libisofs has a limit of 125,829,120 bytes for thesize of the overall directory tree. This suffices for about 300,000 filesof normal name length. If the limit gets exceeded, a FAILURE event will be issued and the ISO production will not happen.
Set a string of 16 digits "0" to "9"and letters "a" to "f", which will be used as unique serial number ofan emerging HFS+ filesystem.
-hfsplus-block-size number
Set the allocation block size tobe used when producing HFS+ filesystems. Permissible are 512, 2048, or 0.The latter lets the program decide.
-apm-block-size number
Set the block size to be used whendescribing partitions by an Apple Partition Map. Permissible are 512, 2048, or 0. The latter lets the program decide.
Note that size 512 is not compatible with production of GPT, and thatsize 2048 will not be mountable -t hfsplus at least by older Linux kernels.
-hfsplus-file-creator-type creator type iso_rr_path
Set the HFS+ creator and type attributes of a file in the emerging image.These are two codes of 4 characters each.
-hfs-bless-by blessing iso_rr_path
Issue a HFS+ blessing. They are roles which can be attributed toup to four directories and a data file:
"ppc_bootdir", "intel_bootfile", "show_folder", "os9_folder", "osx_folder".
They may be abbreviated as "p", "i", "s", "9", and "x".
Each such role can be attributed to at most one file object. "intel_bootfile"is the one that would apply to a data file. All others apply to directories.No file object can bear more than one blessing.
-hfs-bless disk_path
Issue HFS+ blessing "ppc_bootdir" to the directory which stems from thedirectory disk_path in the local filesystem tree.
This works only if there is at least one data file underneath the directory.disk_path can become ambiguous if files from different local filesystemsub-trees are put into the same sub-tree of the ISO image.Consider to use -hfs-bless-by "p" for unambiguous addressing via iso_rr_path.
Settings for file hiding:
-hide disk_path_pattern
Make files invisible in the directory tree of ISO 9660 and Rock Ridge,if their disk_path matches the given shell parser pattern.The data content of such hidden files will be included in theresulting image, even if they do not show up in any directory.But you will need own means to find nameless data in the image.
This command does not apply to the boot catalog.
-hide-list disk_path
Perform -hide using each line out of file disk_path as argumentdisk_path_pattern.
-hide-joliet disk_path_pattern
Like option -hide but making files invisible in the directory tree of Joliet,if their disk_path matches the given shell parser pattern.
-hide-joliet-list disk_path
Perform -hide-joliet using each line out of file disk_path as argumentdisk_path_pattern.
-hide-hfsplus disk_path_pattern
Like option -hide but making files invisible in the directory tree of HFS+,if their disk_path matches the given shell parser pattern.
-hide-hfsplus-list disk_path
Perform -hide-hfsplus using each line out of file disk_path as argumentdisk_path_pattern.
ISO image ID strings:

The following strings and file addresses get stored in the Primary VolumeDescriptor of the ISO9660 image. The file addresses are ISO 9660paths. These files should have iso_rr_paths which consist only ofthe characters [A-Z0-9_] and exactly one dot which separatesat most 8 characters from at most 3 characters.

-V text
Set the Volume Id of the ISO image.xorriso accepts any text up to 32 characters,but according to rarely obeyed specs stricter rules apply:
Conformant are ASCII characters out of [A-Z0-9_]. Like: "IMAGE_23"
Joliet allows 16 UCS-2 characters. Like: "Windows name"
Be aware that the volume id might get used automatically as name of themount point when the medium is inserted into a playful computer system.
-volid text
Alias of -V.
-volset text
Set the Volume Set Id of the ISO image.Permissible are up to 128 characters.
-P text
Set the Publisher Id of the ISO image. This may identify the person ororganisation who specified what shall be recorded.Permissible are up to 128 characters.
-publisher text
Alias of -P.
-A text
Set the Application Id of the ISO image. This may identify the specification of how the data are recorded.Permissible are up to 128 characters.
The special text "@xorriso@" gets converted to the id string of xorrisowhich is normally written as Preparer Id. It is a wrong tradition to writethe program id as Application Id.
-appid text
Alias of -A.
-sysid text
Set the System Id of the ISO image. This mayidentify the system which can recognize and act upon the content of theSystem Area in image blocks 0 to 15.Permissible are up to 32 characters.
-p text
Set the Preparer Id of the ISO image. This mayidentify the person or other entity which controls the preparation of the datawhich shall be recorded. Normally this should be the id of xorriso and notof the person or program which operates xorriso. Please avoid to change it.Permissible are up to 128 characters.
The special text "@xorriso@" gets converted to the id string of xorrisowhich is default at program startup.
-preparer text
Alias of -p.
-abstract iso_path
Set the address of the Abstract File of the ISO image. This shouldbe the ISO 9660 path of a file in the image which contains an abstractstatement about the image content.Permissible are up to 37 characters.
-biblio iso_path
Set the address of the Biblio File of the ISO image. This shouldbe the ISO 9660 path of a file in the image which contains bibliographicrecords.Permissible are up to 37 characters.
-copyright iso_path
Set the address of the Copyright File of the ISO image. This shouldbe the ISO 9660 path of a file in the image which contains a copyrightstatement.Permissible are up to 37 characters.
Set a timestring that overrides ISO image creation and modification timestampsliterally.It must consist of 16 decimal digits which form YYYYMMDDhhmmsscc, withYYYY between 1970 and 2999. Time zone is GMT.It is supposed to match this GRUB line:

 search --fs-uuid --set YYYY-MM-DD-hh-mm-ss-cc
E.g. 2010040711405800 is 7 Apr 2010 11:40:58 (+0 centiseconds).
Among the influenced timestamps are:isohybrid MBR id, El Torito boot catalog file, HFS+ superblock.
--application_use character|0xXY|disk_path
Specify the content of the Application Use field which can take at most512 bytes.
If the parameter of this command is empty, then the field is filledwith 512 0-bytes. If it is a single character, then it gets repeated 512 times.If it begins by "0x" followed by two hex digits [0-9a-fA-F], then the digitsare read as byte value which gets repeated 512 times.
Any other parameter text is used as disk_path to open a data file and toread up to 512 bytes from it. If the file is smaller than 512 bytes, then theremaining bytes in the field get set to binary 0.
El Torito Bootable ISO images:

The precondition for a bootable ISO image is to have in the ISO imagethe files of a boot loader. The boot facilities of computers getdirected to such files, which usually execute further program filesfrom the ISO image.xorrisofs can produce several kinds of boot block or boot record,which become part of the ISO image, and get interpreted by the accordingboot facility.

An El Toritoboot record points the bootstrapping facility to a boot catalogwith one or more boot images, which are binary program files stored inthe ISO image.The content of the boot image files is not in the scope of El Torito.
xorriso composes the boot catalog according to the boot imagefiles given and structured by options -b, -e, -eltorito-alt-boot,and --efi-boot. Often it contains only one entry.
Normally the boot images are data files inside the ISO filesystem. Byspecial path "--interval:appended_partition_NNN:all::" it is possible torefer to an appended partition. The number NNN gives the partition numberas used with the corresponding option -append_partition.E.g.:

  -append_partition 2 0xef /tmp/efi.img

  -e --interval:appended_partition_2:all::
El Torito gets interpreted by boot facilities PC-BIOS and EFI.Most bootable GNU/Linux CDs are equipped with ISOLINUX or GRUB boot imagesfor PC-BIOS.
xorrisofs supports the example options out of the ISOLINUX wiki,the options used in GRUB script grub-mkrescue, and the example in theFreeBSD AvgLiveCD wiki.

For CD booting via boot facilities other than PC-BIOS and EFI, andfor booting from USB sticks or hard disks, see the next sectionabout the System Area.

-b iso_rr_path
Specify the boot image file which shall be mentioned in the currententry of the El Torito boot catalog. It will be marked as suitable forPC-BIOS.
With boot images from ISOLINUX and GRUB this option should be accompanied byoptions -c , -no-emul-boot , -boot-load-size 4 , -boot-info-table.
-eltorito-boot iso_rr_path
Alias of -b.
Finalize the current El Torito boot catalog entry and begin a new one.A boot image file and all its necessary options shall be specified beforeoption -eltorito-alt-boot.All further El Torito boot options apply to the new catalogentry. Up to 32 catalog entries are possible.
-e iso_rr_path
Specify the boot image file which shall be mentioned in the currententry of the El Torito boot catalog. It will be marked as suitable for EFI.
Option -e should be followed by option -no-emul-boot and no other El Toritooptions before an eventual -eltorito-alt-boot.
--efi-boot iso_rr_path
Perform -eltorito-alt-boot, option -e with the giveniso_rr_path, -no-emul-boot, and again -eltorito-alt-boot. This gesture isused for achieving EFI-bootability of the GRUB2 rescue CD.
-eltorito-platform "x86"|"PPC"|"Mac"|"efi"|0xnn|nnn
Set the Platform Id number for the next option -b or -eltorito-boot.The number may be chosen by a platform name or by a number between0 and 255 (0x00 and 0xFF). "x86" = 0 is for PC-BIOS,"PPC" = 1 for some PowerPC systems, "Mac" = 2 for some MacIntosh systems,"efi" = 0xEF for EFI on modern PCs with x86 compatible CPUs or others.
If the new platform id differs from the previous one, -eltorito-alt-bootgets performed.
-boot-load-size number|"full"
Set the number of 512-byte blocks to be loaded at boot timefrom the boot image in the current catalog entry.
Non-emulating BIOS bootimages usually need a load size of 4.Nevertheless the default setting of mkisofs is to use the full size of theboot image rounded up to a multiple of 4 512-byte blocks. This defaultmay be explicitly enforced by the word "full" instead of a number.
EFI boot images usually get set the number of blocks occupiedby the boot image file.
El Torito cannot represent load sizes higher than 65535.
Mark the boot image in the current catalog entry as emulated hard disk.(Not suitable for any known boot loader.)
Mark the boot image in the current catalog entry as not emulatingfloppy or hard disk. (This is to be used with all known boot loaders.)
If neither -hard-disk-boot nor -no-emul-boot is given, then theboot image will be marked as emulating a floppy. (Not suitable for any known boot loader.)
-eltorito-id text|56_hexdigits
Define the ID string of the boot catalogsection where the boot image will be listed. If the value consists of 56characters [0-9A-Fa-f] then it is converted into 28 bytes, else the first28 characters become the ID string.The ID string of the first boot image becomes the overall catalog ID.It is limited to 24 characters. Other id_strings become section IDs.
-eltorito-selcrit hexdigits
Define the Selection Criteria of the boot image.Up to 20 bytes get read from the given characters [0-9A-Fa-f].They get attributed to the boot image entry in the catalog.
Overwrite bytes 8 to 63 in the current boot image. The information will besupplied by xorriso in the course of image production: Block address ofthe Primary Volume Descriptor, block address of the boot image file,size of the boot image file.
Overwrite bytes 2548 to 2555 in the current boot image by the addressof that boot image.The address is written as 64 bit little-endian number. It is the2KB block address of the boot image content, multiplied by 4,and then incremented by 5.
-c iso_rr_path
Set the address of the El Torito boot catalog file within the image.This file address is not significant for the booting PC-BIOS or EFI,but it may later be read by other programs in order to learn aboutthe available boot images.
-eltorito-catalog iso_rr_path
Alias of -c.
Prevent the El Torito boot catalog from appearing as filein the directory trees of the image.
System Area, MBR, GPT, APM, other boot blocks:

The first 16 blocks of an ISO image are the System Area.It is reserved for system dependent boot software. This may be theboot facilities and partition tables of various hardware architectures.
A MBR (Master Boot Record) contains boot code and a partition table.It is read by PC-BIOS when booting from USB stick or hard disk,and by PowerPC CHRP or PReP when booting.An MBR partition with type 0xee indicates the presence of GPT.
A GPT (GUID Partition Table) marks partitions in a more modern way.It is read by EFI when booting from USB stick or hard disk, and may be usedfor finding and mounting a HFS+ partition inside the ISO image.
An APM (Apple Partition Map) marks the HFS+ partition.It is read by Macs for booting and for mounting.
MBR, GPT and APM are combinable. APM occupies the first 8 bytes ofMBR boot code. All three do not hamper El Torito booting from CDROM.
xorrisofs supports further boot facilities:MIPS Big Endian (SGI), MIPS Little Endian (DEC), SUN SPARC, HP-PA, DEC Alpha.Those are mutually not combinable and also not combinable with MBR, GPT,or APM.

Several of the following options expect disk paths as input but also acceptdescription strings for the libisofs interval reader, which is able to cutout data from disk files or -indev and to zeroize parts of the content:-G, -generic-boot, --embedded-boot, --grub2-mbr,-isohybrid-mbr, -efi-boot-part, -prep-boot-part, -B, -sparc-boot,-append_partition.
The description string consistsof the following components, separated by colon ':'

The component "--interval" states that this is nota plain disk path but rather a interval reader description string.
The component Flags modifies the further interpretation:
"local_fs" demands to read from a file depicted by the path in Source.
"imported_iso" demands to read from the -indev. This works only if -outdevis not the same as -indev. The Source component is ignored.
"appended_partition_NNN" with a decimal number NNN works only for optionswhich announce El Torito boot image paths: -b, -e, --efi-boot. The number givesthe partition number as used with the corresponding option -append_partition.
The component Interval consists of two byte address numbers separated by a "-" character. E.g. "0-429" means to read bytes 0 to 429.
The component Zeroizers consists of zero or more comma separated strings.They define which part of the read data to zeroize. Byte number 0 meansthe byte read from the Interval start address.Each string may be one of:
"zero_mbrpt" demands to zeroize the MBR partition table ifbytes 510 and 511 bear the MBR signature 0x55 0xaa.
"zero_gpt" demands to check for a GPT header in bytes 512 to 1023,to zeroize it and its partition table blocks.
"zero_apm" demands to check for an APM block 0 and to zeroizeits partition table blocks.
Start_byte"-"End_byte demands to zeroize the read-in bytes beginningwith number Start_byte and ending after End_byte.
The component Source is the file path with flag "local_fs", and ignored withflag "imported_iso".
Byte numbers may be scaled by a suffix out of {k,m,g,t,s,d} meaningmultiplication by {1024, 1024k, 1024m, 1024g, 2048, 512}. A scaled valueend number depicts the last byte of the scaled range.
E.g. "0d-0d" is "0-511".



-G disk_path
Copy at most 32768 bytes from the given disk file to the very start ofthe ISO image.
Other than a El Torito boot image, the file disk_path needs not to be addedto the ISO image. It will not show up as file in the directory trees.
In multi-session situations, the special disk_path "." prevents reading ofa disk file but nevertheless causes the adjustments in theexisting MBR, which were ordered by other options.
-generic-boot disk_path
Alias of -G.
--embedded-boot disk_path
Alias of -G.
--grub2-mbr disk_path
Install disk_path in the System Area and treat it as modern GRUB2 MBR.The content start address of the first bootimage is converted to a count of 512 byte blocks, and an offset of 4 is added.The result is written as 64 bit little-endian number to byte address 0x1b0.
-isohybrid-mbr disk_path
Install disk_path as ISOLINUX isohybrid MBR which makes the boot imagegiven by option -b bootable from USB sticks and hard disks via PC-BIOS.This preparation is normally done by ISOLINUX program isohybridon the already produced ISO image.
The disk path should lead to one of the Syslinux files isohdp[fp]x*.bin .The MBR gets patched according to isohybrid needs. The first partitiondescribes the range of the ISO image. Its start is at block 0 by default,but may be set to 64 disk blocks by option -partition_offset 16.
For the meaning of special disk_path "." see option -G.
Mark the current El Torito boot image (see options -b and -e) in an actuallyinvalid GPT as partition of type Basic Data. This works only with-isohybrid-mbr and has the same impact on the system area as -efi-boot-part.It cannot be combined with -efi-boot-part or -hfsplus.
The first three boot images which are marked by GPT will also show upas partition entries in MBR. The MBR partition of type 0xEF is what actuallyis used by EFI firmware for booting from USB stick.The MBR partition for PC-BIOS gets type 0x00 rather than 0x17 in this case.Often the further MBR entries are the ones which actually get used by EFI.
Mark the current El Torito boot image (see options -b and -e) in GPT aspartition of type HFS+.Impact and restrictions are like with -isohybrid-gpt-basdat.
Mark the current El Torito boot image (see options -b and -e) in ApplePartition Map as partition of type HFS+. This works only with -isohybrid-mbrand has a similar impact on the system area as -hfsplus. It cannot becombined with -efi-boot-part or -hfsplus.
The ISOLINUX isohybrid MBR file must begin by a known pattern of32 bytes of x86 machine code which essentially does nothing. It will getoverwritten by 32 bytes of APM header mock-up.
Control whether -isohybrid-gpt-basdat, -isohybrid-gpt-hfsplus, and-isohybrid-apm-hfsplus apply even if not -isohybrid-mbr is present.No MBR partition of type 0xee emerges, even if GPT gets produced.Gaps between GPT and APM partitions will not be filled by more partitions.Appended partitions get mentioned in APM if other APM partitions emerge.
-iso_mbr_part_type "default"|number|type_guid
Set the partition typeof the MBR or GPT partition which represents the ISO or at least protects it.
Number may be 0x00 to 0xff. The text "default" re-enables the default typesof the various occasions to create an ISO MBR partition.This is without effect if no such partition emerges by other settings orif the partition type is prescribed mandatorily like 0xee for GPT protectiveMBR or 0x96 for CHRP.
If instead a type_guid is given by a 32-digit hex string likea2a0d0ebe5b9334487c068b6b72699c7 or by a structured text likeEBD0A0A2-B9E5-4433-87C0-68B6B72699C7, then it will be used as partition typeif the ISO filesystem appears as partition in GPT.In MBR, C12A7328-F81F-11D2-BA4B-00A0C93EC93B will be mapped to 0xef.Any other GUID will be mapped to 0x83.
Patch the System Area by a simple PC-DOS partition table where partition 1claims the range of the ISO image but leaves the first block unclaimed.This is mutally exclusive to option -isohybrid-mbr.
Enforce an MBR partition with "bootable/active" flag if options like--protective-msdos-label or --grub2-mbr are given.These options normally cause the flag to be set if there is anMBR partition of type other than 0xee or 0xef.If no such partition exists, then no bootflag is set, unless--mbr-force-bootable forces creation of a dummy partitionof type 0x00 which covers only the first block of the ISO image.
If no bootable MBR is indicated by other options and a partition gets createdby -append_partition, then --mbr-force-bootable causes abootflag like it would do with e.g. --protective-msdos-label.
-partition_offset 2kb_block_adr
Cause a partition table with a single partition that begins at thegiven block address. This is counted in 2048 byteblocks, not in 512 byte blocks. If the block address is non-zero then it mustbe at least 16. Values larger than 16 are hardly of use.A non-zero partition offset causes two superblocks to begenerated and two sets of directory trees. The image is then mountable from itsabsolute start as well as from the partition start.
The offset value of an ISO image gets preserved when a new session is addedto a loaded image.So the value defined here is only in effect if a new ISO image gets written.
-partition_hd_cyl number
Set the number of heads per cylinder for the MBR partition table.0 chooses a default value. Maximum is 255.
-partition_sec_hd number
Set the number of sectors per head for the MBR partition table.0 chooses a default value. Maximum is 63.
The product partition_sec_hd * partition_hd_cyl * 512 is the cylinder size.It should be divisible by 2048 in order to make exact alignment possible.With appended partitions and -appended_part_as_gpt there is no limit forthe number of cylinders. Else there may be at most 1024 of them.If the cylinder size is too small to stay below the limit,then appropriate values of partition_hd_cyl are chosen with partition_sec_hd 32 or 63. If the image is larger than 8,422,686,720 bytes,then the cylinder size constraints cannot be fulfilled for MBR.They seem not overly important anyway.Flat block addresses in partition tables are good for 1 TiB.
-partition_cyl_align mode
Control image size alignment to an integer number of cylinders.It is prescribed by isohybrid specs and it seems to please program fdisk.Cylinder size must be divisible by 2048.Images larger than 8,323,596,288 bytes cannot be aligned in MBR partitiontable.
Mode "auto" is default. Alignment by padding happens only ifoption -isohybrid-mbr is given.
Mode "on" causes alignment by padding with option--protective-msdos-label too.Mode "all" is like "on" but also pads up partitions from -append_partition to an aligned size.
Mode "off" disables alignment unconditionally.
-append_partition partition_number type_code disk_path
Cause a prepared filesystem image to be appended to the ISO image and to bedescribed by a partition table entry in a boot block at the start of theemerging ISO image. The partition entry will bear the size of the submittedfile rounded up to the next multiple of 2048 bytes or to the next multipleof the cylinder size.
Beware of subsequent multi-session runs. The appended partition will getoverwritten.
partition_number may be 1 to 4. Number 1 will put the whole ISO image intothe unclaimed space before partition 1. So together with most xorriso MBRor GPT features, number 2 would be the most natural choice.
The type_code may be "FAT12", "FAT16", "Linux",or a hexadecimal number between 0x00 and 0xff. Not all those numbers willyield usable results. For a list of codes search the Internet for"Partition Types" or run fdisk command "L".If the partition appears in GPT then type_code 0xef is mapped to the EFI SystemPartition Type GUID. All others get mapped to Basic Data Type GUID.
type_code may also be a type GUID as plain hex string likea2a0d0ebe5b9334487c068b6b72699c7 or as structured text likeEBD0A0A2-B9E5-4433-87C0-68B6B72699C7. It will be used if the partition ismentioned in GPT. In MBR, C12A7328-F81F-11D2-BA4B-00A0C93EC93B will be mappedto 0xef. Any other GUID will be mapped to 0x83.In APM, 48465300-0000-11AA-AA11-00306543ECAC will be mapped to partitiontype "Apple_HFS", any other to "Data".
If some other command causes the production of GPT, then the appendedpartitions will be mentioned there too, even if not -appended_part_as_gptis given.
Marks partitions from -append_partition in GPT rather than in MBR.In this case the MBR shows a single partitionof type 0xee which covers the whole output data.
By default, appended partitions get marked in GPT only if GPT is producedbecause of other options.
Marks partitions from -append_partition in Apple Partition Map, too.
By default, appended partitions get marked in APM only if APM is producedbecause of other options and -part_like_isohybrid is enabled.
-efi-boot-part disk_path
Copy a file from disk into the emerging ISO image and mark it by a GPT entry asEFI System Partition. EFI boot firmware is supposed to use a FAT filesystemimage in such a partition for booting from USB stick or hard disk.
Instead of a disk_path, the word --efi-boot-image may be given.It exposes in GPT the content of the first El Torito EFI boot image asEFI system partition. EFI boot images are introduced by options -e or--efi-boot.The affected EFI boot image cannot show up in HFS+ because it is storedoutside the HFS+ partition.
--gpt_disk_guid value
Control whether an emerging GPT shall get a randomly generated disk GUIDor whether the GUID is supplied by the user.Value "random" is default. Value "modification-date" produces a low qualityGUID from the value set by option --modification-date=.
A string of 32 hex digits, or a RFC 4122 compliant GUID string may be used toset the disk GUID directly. UEFI prescribes the first three components of a RFC 4122 GUID string to be byte-swapped in the binary representation:
E.g. --gpt_disk_guid 2303cd2a-73c7-424a-a298-25632da7f446equals --gpt_disk_guid 2acd0323c7734a42a29825632da7f446
The partition GUIDs get generated by minimally varying the disk GUID.
Mark the block range of the whole emerging ISO image as MBR partition of type0x96. This is not compatible with any other feature that produces MBRpartition entries. It makes GPT unrecognizable.
CHRP is often used in conjunction with HFS. It is not yet tested whether HFS+filesystems produced with option -hfsplus would boot on anyCHRP capable machine which does not boot pure ISO 9660 as well.
Alias of -chrp-boot-part.
-prep-boot-part disk_path
Copy a file from disk into the emerging ISO image and mark it by a MBRpartition entry of type 0x41. PReP boot firmware is supposed to readthe content of the partition as single ELF executable file.This option is compatible with other MBR partitions and with GPT.
-mips-boot iso_rr_path
Declare a data file in the image to be aMIPS Big Endian boot file and cause production of a MIPS Big Endian VolumeHeader. This is mutually exclusive with production of other boot blockslike MBR.It will overwrite the first 512 bytes of any data provided by -G.Up to 15 boot files can be declared by multiple -mips-boot options.
-mipsel-boot iso_rr_path
Declare a data file in the image to be theMIPS Little Endian boot file. This is mutually exclusive with other bootblocks.It will overwrite the first 512 bytes of any data provided by -G.Only a single boot file can be declared by -mipsel-boot.
-B disk_path[,disk_path ...]
Cause one or more data files on disk to be written after the end of theISO image. A SUN Disk Label will be written into the first 512 bytes of theISO image which lists this image as partition 1 and the given disk_paths aspartition 2 up to 8.
The disk files should contain suitable boot images for SUN SPARC systems.
The pseudo disk_path "..." causes that all empty partition entries becomecopies of the last non-empty entry. If no other disk_path is given before"..." then all partitions describe the ISO image. In this case, the bootloader code has to be imported by option -G.
-sparc-boot disk_path[,disk_path ...]
Alias of -B.
-sparc-label text
Set the ASCII label text of a SUN Disk Label.
--grub2-sparc-core iso_rr_path
Cause the content address and size of the given data file in the imageto be written after the SUN Disk Label. Both numbers are counted in bytes.The address is written as 64 bit big-endian number to byte 0x228.The size is written as 32 bit big-endian number to byte 0x230.
-hppa-cmdline text
Set the PALO command line for HP-PA. Up to 1023 characters are permittedby default. With -hppa-hdrversion 4 the limit is 127.
Note that the first five -hppa options are mandatory, if any of the -hppaoptions is given. Only option -hppa-hdrversion is allowed to be missing.
-hppa-bootloader iso_rr_path
Designate the given path as HP-PA bootloader file.
-hppa-kernel-32 iso_rr_path
Designate the given path as HP-PA 32 bit kernel file.
-hppa-kernel-64 iso_rr_path
Designate the given path as HP-PA 64 bit kernel file.
-hppa-ramdisk iso_rr_path
Designate the given path as HP-PA RAM disk file.
-hppa-hdrversion number
Choose between PALO header version 5 (default) and version 4.For the appropriate value see in PALO source code: PALOHDRVERSION.
-alpha-boot iso_rr_path
Declare a data file in the image to be the DEC Alpha SRM Secondary BootstrapLoader and cause production of a boot sector which points to it.This is mutually exclusive with production of other boot blocks like MBR.
Character sets:

Character sets should not matter as long as only english alphanumericcharacters are used for file names or as long as all writers and readersof the medium use the same character set.Outside these constraints it may be necessary to let xorriso convert bytecodes.
A conversion from input character set to the output character set isperformed when an ISO image gets written.Vice versa there is a conversion from output character set to theinput character set when an ISO image gets loaded.The sets can be defined by options -input-charset and -output-charset,if needed.

-input-charset character_set_name
Set the character set from which to convert disk file names wheninserting them into the ISO image.
-output-charset character_set_name
Set the character set from which to convert names of loaded ISO imagesand to which to convert names when writing ISO images.
Jigdo Template Extraction:

From man genisoimage:"Jigdo is a tool to help in the distribution of large files like CD andDVD images; see for more details. Debian CDsand DVD ISO images are published on the web in jigdo format to allowend users to download them more efficiently."
If the use of libjte was enabled at compile time of xorriso, thenxorrisofs can produce a .jigdo and a .template file together with asingle-session ISO image. If not, then Jigdo options will cause aFAILURE event, which normally leads to program abort.
One may determine the ability for Jigdo by:

  $ xorrisofs -version 2>&1 | grep '^libjte' && echo YES 

The .jigdo file contains checksums and symbolic file addresses.The .template file contains the compressed ISO image with reference tagsinstead of the content bytes of the listed files.
Input for this process are the normal arguments for a xorrisofssession with no image loaded, and a checksum file which lists thosedata files which may belisted in the .jigdo file and externally referenced in the .template file.Each designated file is represented in the checksum file by a