GENISOIMAGE(1)

📦
version 1.1.11 · 2 versions
, in alpine 3.24, debian bookworm, ubuntu jammy, ubuntu noble

💿 genisoimage — the genisoimage(1) manual, but make it cute

🌸 NAME

genisoimage — bestie, this makes ISO9660/Joliet/HFS filesystems, optionally with Rock Ridge attributes sprinkled on top ✨

🎀 SYNOPSIS

genisoimage [options] [-o filename] pathspec [pathspec ...]

🦋 DESCRIPTION

okay so. genisoimage is a pre-mastering program — meaning it builds the filesystem image before anyone burns anything — and it generates ISO9660/Joliet/HFS hybrid filesystems. main character energy fr 💅

genisoimage is capable of generating the System Use Sharing Protocol records (SUSP) specified by the Rock Ridge Interchange Protocol. That's the thing that further describes the files inside the ISO9660 filesystem to a Unix host, and it gives you the good stuff: long filenames, UID/GID, POSIX permissions, symbolic links, and block and character device files. like, all the things you'd actually miss 😭

If you specify Joliet or HFS hybrid command line options, genisoimage will create the additional filesystem metadata needed for Joliet or HFS. Otherwise genisoimage will generate a pure ISO9660 filesystem. no extras, just vibes 🌈

genisoimage can generate a true (or shared) HFS hybrid filesystem. The same files are seen as HFS files when accessed from a Macintosh and as ISO9660 files when accessed from other machines. HFS stands for Hierarchical File System and is the native filesystem used on Macintosh computers. 🍎

As an alternative, genisoimage can generate the Apple Extensions to ISO9660 for each file. These extensions provide each file with CREATOR, TYPE and certain Finder flags when accessed from a Macintosh. See the HFS MACINTOSH FILE FORMATS section below. 👀

genisoimage takes a snapshot of a given directory tree, and generates a binary image which will correspond to an ISO9660 and/or HFS filesystem when written to a block device. it's giving "freeze the moment" 📸

Every single file written to the ISO9660 filesystem must have a filename in the 8.3 format (up to 8 characters, period, up to 3 characters, all uppercase), even if Rock Ridge is in use. This filename is used on systems that are not able to make use of the Rock Ridge extensions (such as MS-DOS), and each filename in each directory must be different from the other filenames in the same directory. genisoimage generally tries to form correct names by forcing the Unix filename to uppercase and truncating as required, but often this yields unsatisfactory results when the truncated names are not all unique. 😬

So here's the trick: genisoimage assigns weightings to each filename, and if two names that are otherwise the same are found, the name with the lower priority is renamed to include a 3-digit number (guaranteed to be unique). For example, the two files foo.bar and foo.bar.~1~ could be rendered as FOO.BAR;1 and FOO000.BAR;1. slay, conflict resolved 💅

When used with various HFS options, genisoimage will attempt to recognise files stored in a number of Apple/Unix file formats and will copy the data and resource forks as well as any relevant Finder information. See the HFS MACINTOSH FILE FORMATS section below for more about formats genisoimage supports.

⚠️ Note that genisoimage is not designed to communicate with the writer directly. Most writers have proprietary command sets which vary from one manufacturer to another, and you need a specialized tool to actually burn the disc. wodim is one such tool. The latest version of wodim is available from http://www.cdrkit.org/. 🔥

pathspec is the path of the directory tree to be copied into the ISO9660 filesystem. Multiple paths can be specified, and genisoimage will merge the files found in all of the specified path components to form the filesystem image. bestie it just combines them 🫶

If the option -graft-points has been specified, it is possible to graft the paths at points other than the root directory, and it is possible to graft files or directories onto the cdrom image with names different than what they have in the source filesystem. This is easiest to illustrate with a couple of examples. Let's start by assuming that a local file ../old.lis exists, and you wish to include it in the cdrom image.

foo/bar/=../old.lis

will include old.lis in the cdrom image at /foo/bar/old.lis, while

foo/bar/xxx=../old.lis

will include old.lis in the cdrom image at /foo/bar/xxx. The same sort of syntax can be used with directories as well. genisoimage will create any directories required such that the graft points exist on the cdrom image — the directories do not need to appear in one of the paths. By default, any directories that are created on the fly like this will have permissions 0555 and appear to be owned by the person running genisoimage. If you wish other permissions or owners of the intermediate directories, see -uid, -gid, -dir-mode, -file-mode and -new-dir-mode. ✨

genisoimage will also run on Windows machines when compiled with Cygnus' cygwin (available from http://www.cygwin.com/). Therefore most references in this man page to Unix can be replaced with Win32. windows girlies you're included 🪟💖

✨ OPTIONS ✨

Several options can be specified as defaults in a .genisoimagerc configuration file, as well as on the command line. If a parameter is specified in both places, the setting from the command line is used. For details on the format and possible locations of this file, see genisoimagerc(5). 💜

  • -abstract file — Specifies the abstract filename. There is space for 37 characters. Equivalent to ABST in the .genisoimagerc file.
  • -A application_id — Specifies a text string that will be written into the volume header. This should describe the application that will be on the disc. There is space for 128 characters. Equivalent to APPI in the .genisoimagerc file.
  • -allow-limited-size — When processing files larger than 2GiB which cannot be easily represented in ISO9660, add them with a shrunk visible file size to ISO9660 and with the correct visible file size to the UDF system. The result is an inconsistent filesystem and users need to make sure that they really use UDF rather than ISO9660 driver to read a such disk. Implies enabling -udf. 😵💫
  • -allow-leading-dots
  • -ldots — Allow ISO9660 filenames to begin with a period. Usually, a leading dot is replaced with an underscore in order to maintain MS-DOS compatibility. This violates the ISO9660 standard, but it happens to work on many systems. Use with caution. 🙈
  • -allow-lowercase — This options allows lowercase characters to appear in ISO9660 filenames. This violates the ISO9660 standard, but it happens to work on some systems. Use with caution.
  • -allow-multidot — This options allows more than one dot to appear in ISO9660 filenames. A leading dot is not affected by this option, it may be allowed separately using -allow-leading-dots. This violates the ISO9660 standard, but it happens to work on many systems. Use with caution.
  • -biblio file — Specifies the bibliographic filename. There is space for 37 characters. Equivalent to BIBL in the .genisoimagerc file.
  • -cache-inodes
  • -no-cache-inodes — Enable or disable caching inode and device numbers to find hard links to files. If genisoimage finds a hard link (a file with multiple names), the file will also be hard-linked on the CD, so the file contents only appear once. This helps to save space. -cache-inodes is default on Unix-like operating systems, but -no-cache-inodes is default on some other systems such as Cygwin, because it is not safe to assume that inode numbers are unique on those systems. (Some versions of Cygwin create fake inode numbers using a weak hashing algorithm, which may produce duplicates.) If two files have the same inode number but are not hard links to the same file, genisoimage -cache-inodes will not behave correctly. -no-cache-inodes is safe in all situations, but in that case genisoimage cannot detect hard links, so the resulting CD image may be larger than necessary. 😭
  • -alpha-boot alpha_boot_image — Specifies the path and filename of the boot image to be used when making an Alpha/SRM bootable CD. The pathname must be relative to the source path specified to genisoimage.
  • -hppa-bootloader hppa_bootloader_image — Specifies the path and filename of the boot image to be used when making an HPPA bootable CD. The pathname must be relative to the source path specified to genisoimage. Other options are required, at the very least a kernel filename and a boot command line. See the HPPA NOTES section below for more information.
  • -hppa-cmdline hppa_boot_command_line — Specifies the command line to be passed to the HPPA boot loader when making a bootable CD. Separate the parameters with spaces or commas. More options must be passed to genisoimage, at the very least a kernel filename and the boot loader filename. See the HPPA NOTES section below for more information.
  • -hppa-kernel-32 hppa_kernel_32
  • -hppa-kernel-64 hppa_kernel_64 — Specifies the path and filename of the 32-bit and/or 64-bit kernel images to be used when making an HPPA bootable CD. The pathnames must be relative to the source path specified to genisoimage. Other options are required, at the very least the boot loader filename and the boot command line. See the HPPA NOTES section below for more information.
  • -hppa-ramdisk hppa_ramdisk_image — Specifies the path and filename of the ramdisk image to be used when making an HPPA bootable CD. The pathname must be relative to the source path specified to genisoimage. This parameter is optional. Other options are required, at the very least a kernel filename and the boot command line. See the HPPA NOTES section below for more information.
  • -mips-boot mips_boot_image — Specifies the path and filename of the boot image to be used when making an SGI/big-endian MIPS bootable CD. The pathname must be relative to the source path specified to genisoimage. This option may be specified several times, to store up to 15 boot images. 🔥
  • -mipsel-boot mipsel_boot_image — Specifies the path and filename of the boot image to be used when making a DEC/little-endian MIPS bootable CD. The pathname must be relative to the source path specified to genisoimage.
  • -B img_sun4,img_sun4c,img_sun4m,img_sun4d,img_sun4e —
  • -sparc-boot img_sun4,img_sun4c,img_sun4m,img_sun4d,img_sun4e — bestie, this one is for making a bootable CD for SPARC systems 🦋. You hand it a comma-separated list of boot images, and it does the mapping for you: partition 0 gets the ISO9660 image, and the first image file gets mapped to partition 1. The list can have up to 7 fields, and yes, empty fields are allowed (she's flexible like that 💅). This option is required to make a bootable CD for Sun SPARC systems.

So here's the tea 🫖: if -B or -sparc-boot has been specified, the first sector of the resulting image will contain a Sun disk label. That disk label specifies slice 0 for the ISO9660 image and slices 1 to 7 for the boot images you specified with this option. Byte offsets 512 to 8191 within each of the additional boot images must contain a primary boot that works for the appropriate SPARC architecture. The rest of each image usually contains a UFS filesystem used for the primary kernel boot stage.

The implemented boot method is the one found with SunOS 4.x and SunOS 5.x ✨. But no cap, it doesn't depend on SunOS internals — only on properties of the Open Boot prom, so it should be usable for any OS for SPARC systems. For more info, peep the NOTES section below 👀.

And now the iconic part: if the special filename ... is used, the actual and all following boot partitions are mapped to the previous partition. And if genisoimage is called with -G image -B ..., all boot partitions are mapped to the partition that contains the ISO9660 filesystem image, and the generic boot image that lives in the first 16 sectors of the disc is used for all architectures. Slay 🎀.

  • -G generic_boot_image — gives you the path and filename of the generic boot image to be used when making a generic bootable CD 🌈. That boot image gets placed on the first 16 sectors of the CD, right before the ISO9660 primary volume descriptor. And if you use this together with -sparc-boot, the Sun disk label will overlay the first 512 bytes of the generic boot image. Overlay, not replace — she's layering ✨.
  • -b eltorito_boot_image — the path and filename of the boot image used when making an El Torito bootable CD for x86 PCs 💻. The pathname must be relative to the source path specified to genisoimage. This option is required to make an El Torito bootable CD. The boot image must be exactly 1200 kB, 1440 kB or 2880 kB, and genisoimage will use this size when creating the output ISO9660 filesystem. The PC BIOS will use the image to emulate a floppy disk, so the first 512-byte sector should contain PC boot code. This will work, for example, if the boot image is a LILO-based boot floppy 🍓.

If the boot image is not an image of a floppy, you need to add either -hard-disk-boot or -no-emul-boot. And if the system should not boot off the emulated disk, use -no-boot.

Sorting tea ☕: if -sort has not been specified, the boot images are sorted with low priority (+2) to the beginning of the medium. If you don't like this, you need to specify a sort weight of 0 for the boot images.

  • -eltorito-alt-boot — start with a new set of El Torito boot parameters 🎀. Up to 63 El Torito boot entries may be stored on a single CD. Sixty-three!! That's a lot of boots bestie 👑
  • -hard-disk-boot — tells it that the boot image used to create El Torito bootable CDs is a hard disk image 💾. The image must begin with a master boot record that contains a single partition.
  • -no-emul-boot — tells it that the boot image used to create El Torito bootable CDs is a "no emulation" image ✨. The system will load and execute this image without performing any disk emulation. Just vibes and execution, no pretend disk 💅.
  • -no-boot — marks the created El Torito CD as not bootable 🙈. The system will still provide an emulated drive for the image, but will boot off a standard boot device instead.
  • -boot-load-seg segment_address — sets the load segment address of the boot image for no-emulation El Torito CDs 🦋.
  • -boot-load-size load_sectors — sets the number of "virtual" (512-byte) sectors to load in no-emulation mode. The default is to load the entire boot file. Some BIOSes may have problems if this is not a multiple of 4 😭.
  • -boot-info-table — patches a 56-byte table with information of the CD-ROM layout in at offset 8 in the boot file ✨. See the EL TORITO BOOT INFO TABLE section for a description of this table.
🚨 GIRL WAIT. If this option is given, the boot file is modified in the source filesystem, so make a copy of this file if it cannot be easily regenerated! Not a drill, she will edit your file fr fr 💀
  • -C last_sess_start,next_sess_start — this one is needed to create a CD Extra or the image of a second session or a higher-level session for a multisession disc 🌈. -C takes two numbers separated by a comma. The first is the first sector in the last session of the disc that should be appended to. The second number is the starting sector number of the new session. You can get the correct numbers by calling wodim -msinfo ... 🔍.

If -C is used in conjunction with -M, genisoimage will create a filesystem image that is intended to be a continuation of the previous session. If -C is used without -M, genisoimage will create a filesystem image intended to be used for a second session on a CD Extra — that's a multisession CD that holds audio data in the first session and an ISO9660 filesystem in the second session 🎵💾.

  • -c boot_catalog — the path and filename of the boot catalog, which is required for an El Torito bootable CD 💅. The pathname must be relative to the source path specified to genisoimage. This file will be inserted into the output tree and not created in the source filesystem, so be sure the specified filename does not conflict with an existing file, or it will be excluded 🙈. Usually a name like boot.catalog is chosen — iconic, classic, no notes.

Sorting again ☕: if -sort has not been specified, the boot catalog is sorted with low priority (+1) to the beginning of the medium. If you don't like this, you need to specify a sort weight of 0 for the boot catalog.

  • -check-oldnames — checks all filenames imported from the old session for compliance with the ISO9660 file naming rules 👀. Without this option, only names longer than 31 characters are checked, since those files are a serious violation of the ISO9660 standard. The audacity of a 32-char filename 😭
  • -check-session file — checks all old sessions for compliance with the actual genisoimage ISO9660 file naming rules ✨. This is a high-level option that combines -M file -C 0,0 -check-oldnames. For the parameter file, see the description of -M.
  • -copyright file — specifies copyright information, typically a filename on the disc 🎀. There is space for 37 characters. Equivalent to COPY in the .genisoimagerc file.
  • -d — do not append a period to files that do not have one 🌸. This violates the ISO9660 standard, but it happens to work on many systems. Use with caution ⚠️.
  • -D — do not use deep directory relocation, and instead just pack them in the way we see them 📦. If ISO9660:1999 has not been selected, this violates the ISO9660 standard, but it happens to work on many systems. Use with caution ⚠️.
  • -dir-mode mode — overrides the mode of directories used to create the image to mode, specified as 4 digits of permission bits as in chmod(1) 💅. This option automatically enables Rock Ridge extensions ✨.
  • -dvd-video — generates a DVD-Video compliant UDF filesystem 🎬. This is done by sorting the order of the content of the appropriate files and by adding padding between the files if needed. Note that the sorting only works if the DVD-Video filenames include uppercase characters only — ALL CAPS OR NOTHING 👑

Note that in order to get a DVD-Video compliant filesystem image, you need to prepare a DVD-Video compliant directory tree. This requires a directory VIDEO_TS (all caps) in the root directory of the resulting DVD, and usually another directory AUDIO_TS. VIDEO_TS needs to include all needed files (filenames must be all caps) for a compliant DVD-Video filesystem 🍓.

  • -f — follow symbolic links when generating the filesystem 🦋. When this option is not in use, symbolic links will be entered using Rock Ridge if enabled, otherwise they will be ignored.
  • -file-mode mode — overrides the mode of regular files used to create the image to mode, specified as 4 digits of permission bits as in chmod(1) 💅. This option automatically enables Rock Ridge extensions ✨.
  • -gid gid — overrides the group ID read from the source files to the value of gid 👥. Specifying this option automatically enables Rock Ridge extensions ✨.
  • -gui — switches the behaviour for a GUI 🖥️. This currently makes the output more verbose but may have other effects in the future 👀.
  • -graft-points — allows use of graft points for filenames 🎀. If this option is used, all filenames are checked for graft points. The filename is divided at the first unescaped equal sign. All occurrences of \ and = characters must be escaped with \ if -graft-points has been specified. Escape or perish bestie 💅
  • -hide glob — hides any files matching glob, a shell wildcard pattern, from being seen in the ISO9660 or Rock Ridge directory 🙈. glob may match any part of the filename or path. If glob matches a directory, the contents of that directory will be hidden. In order to match a directory name, make sure the pathname does not include a trailing / character ⚠️. All the hidden files will still be written to the output CD image file 💾. See also -hide-joliet, and README.hide. This option may be used multiple times ✨.
  • -hide-list file — a file containing a list of shell wildcards to be hidden 📝. See -hide.
  • -hidden glob — adds the hidden (existence) ISO9660 directory attribute for files and directories matching glob, a shell wildcard pattern 👀. This attribute will prevent the files from being shown by some MS-DOS and Windows commands. glob may match any part of the filename or path. In order to match a directory name, make sure the pathname does not include a trailing / character ⚠️. This option may be used multiple times ✨.
  • -hidden-list file — a file full of shell wildcards that'll get the hidden attribute. Basically the list version of -hidden. 📋
  • -hide-joliet glob — hides files and dirs matching glob (a shell wildcard pattern) so they don't show up in the Joliet directory. glob can match any part of the filename or path, bestie. If glob matches a directory, everything inside that directory gets hidden too. Oh and heads up — if you wanna match a directory name, make sure the pathname does not have a trailing / character. 👀 All the hidden files still get written to the output CD image file tho, no cap. This one is usually used together with -hide. Also peep README.hide. You can use this option multiple times. 💅
  • -hide-joliet-list file — a file containing a list of shell wildcards to hide from the Joliet tree. See -hide-joliet.
  • -hide-joliet-trans-tbl — hides the TRANS.TBL files from the Joliet tree. Honestly these files usually don't make sense in the Joliet world anyway, because they list the real name and the ISO9660 name, and both of those may be different from the Joliet name. 💀
  • -hide-rr-moved — renames the directory RR_MOVED to .rr_moved in the Rock Ridge tree. The tea is: it seems literally impossible to completely hide the RR_MOVED directory from the Rock Ridge tree. 🙈 This option just makes the visible tree less confusing for people who don't know what that directory is even for. If you need to have no RR_MOVED directory at all, you should use -D. But note that if -D has been specified, the resulting filesystem is not ISO9660 level-1 compliant and will not be readable on MS-DOS. 😭 Also check the NOTES section.
  • -input-charset charset — the input charset that defines the characters used in local filenames. Wanna see a list of valid charset names? Just call genisoimage -input-charset help. ✨ For a 1:1 mapping you may use default as the charset name. The default initial values are cp437 on DOS-based systems and iso8859-1 on all other systems. See the CHARACTER SETS section below for the deets.
  • -output-charset charset — the output charset that defines the characters that'll be used in Rock Ridge filenames. Defaults to the input charset. See the CHARACTER SETS section below for more.
  • -iso-level level — sets the ISO9660 conformance level. Valid numbers are 1 to 4. Let's break it down:
    • With level 1, files may only consist of one section and filenames are restricted to 8.3 characters.
    • With level 2, files may only consist of one section.
    • With level 3, no restrictions (other than ISO-9660:1988) do apply.
    • With all ISO9660 levels from 1 to 3, all filenames are restricted to uppercase letters, numbers and underscores (_). Filenames are limited to 31 characters, directory nesting is limited to 8 levels, and pathnames are limited to 255 characters.
    • Level 4 officially does not exist, but genisoimage maps it to ISO-9660:1999, which is ISO9660 version 2.
    • With level 4, an enhanced volume descriptor with version number and file structure version number set to 2 is emitted. Directory nesting is not limited to 8 levels, there's no need for a file to contain a dot and the dot has no special meaning, filenames do not have version numbers, and filenames can be up to 207 characters long — or 197 characters if Rock Ridge is used.
When creating Version 2 images, genisoimage emits an enhanced volume descriptor, similar but not identical to a primary volume descriptor. Be careful not to use broken software to make ISO9660 images bootable by assuming a second PVD copy and patching this putative PVD copy into an El Torito VD. ⚠️
  • -J — generates Joliet directory records in addition to regular ISO9660 filenames. This is mainly useful when the discs are gonna be used on Windows machines. Joliet filenames are specified in Unicode and each path component can be up to 64 Unicode characters long. Note that Joliet is not a standard — only Microsoft Windows and Linux systems can read Joliet extensions. 👑 For greater portability, consider using both Joliet and Rock Ridge extensions.
  • -joliet-long — lets Joliet filenames go up to 103 Unicode characters instead of 64. This breaks the Joliet specification, but it appears to work. Use with caution. 😬
  • -jcharset charset — a combo of -J -input-charset charset. See the CHARACTER SETS section below for more.
  • -l — allows full 31-character filenames. Normally the ISO9660 filename is in an 8.3 format that's compatible with MS-DOS, even though the ISO9660 standard allows filenames of up to 31 characters. If you use this option, the disc may be difficult to use on an MS-DOS system, but it'll work on most other systems. Use with caution. 🫶
  • -L — outdated option, bestie; use -allow-leading-dots instead. 💀
  • -jigdo-jigdo jigdo_file — produces a jigdo .jigdo metadata file as well as the filesystem image. See the JIGDO NOTES section below for more info.
  • -jigdo-template template_file — produces a jigdo .template file as well as the filesystem image. See the JIGDO NOTES section below for more info.
  • -jigdo-min-file-size size — specifies the minimum size for a file to be listed in the .jigdo file. Default (and minimum allowed) is 1KB. See the JIGDO NOTES section below for more info.
  • -jigdo-force-md5 path — specifies a file pattern where files must be contained in the externally-supplied MD5 list as supplied by -md5-list. See the JIGDO NOTES section below for more.
  • -jigdo-exclude path — specifies a file pattern where files will not be listed in the .jigdo file. See the JIGDO NOTES section below for more.
  • -jigdo-map path — specifies a pattern mapping for the jigdo file (e.g. Debian=/mirror/debian). See the JIGDO NOTES section below for more.
  • -md5-list md5_file — specifies a file containing the MD5sums, sizes and pathnames of the files to be included in the .jigdo file. See the JIGDO NOTES section below for more.
  • -jigdo-template-compress algorithm — specifies a compression algorithm to use for template data. gzip and bzip2 are currently supported, and gzip is the default. See the JIGDO NOTES section below for more.
  • -log-file log_file — redirects all error, warning and informational messages to log_file instead of the standard error. 📝
  • -m glob — excludes files matching glob (a shell wildcard pattern) from being written to CD-ROM. glob may match either the filename component or the full pathname. This option may be used multiple times. For example:
genisoimage -o rom -m '*.o' -m core -m foobar

would exclude all files ending in .o, or called core or foobar from the image. Note that if you had a directory called foobar, it too (and of course all its descendants) would be excluded. 👀

  • -exclude-list file — a file containing a list of shell wildcards to be excluded. See -m.
  • -max-iso9660-filenames — allows ISO9660 filenames to be up to 37 characters long. This option enables -N since the extra name space is taken from the space reserved for file version numbers. This violates the ISO9660 standard, but it happens to work on many systems. Although a conforming application needs to provide a buffer space of at least 37 characters, discs created with this option may cause a buffer overflow in the reading operating system. Use with extreme care. 😱
  • -M path
  • -M device
  • -dev device — specifies path to an existing ISO9660 image to be merged. The alternate form takes a SCSI device specifier that uses the same syntax as the dev= parameter of wodim. The output of genisoimage will be a new session which should get written to the end of the image specified in -M. Typically this requires multisession capability for the CD recorder used to write the image. This option may only be used in conjunction with -C. 🔥
  • -N — omits version numbers from ISO9660 filenames. This violates the ISO9660 standard, but no one really uses the version numbers anyway. Use with caution. 💅
  • -new-dir-mode mode — specifies the mode, a 4-digit number as used in chmod(1), to use when creating new directories in the filesystem image. The default is 0555.
  • -nobak
  • -no-bak — excludes backup files on the ISO9660 filesystem; that is, filenames that contain the characters ~ or # or end in .bak. These are typically backup files for Unix text editors. 🎀
  • -force-rr — do not use the automatic Rock Ridge attributes recognition for previous sessions. This can work around problems with images created by, e.g., NERO Burning ROM.
  • -no-rr — do not use the Rock Ridge attributes from previous sessions. This may help to avoid problems when genisoimage finds illegal Rock Ridge signatures on an old session.
  • -no-split-symlink-components — don't split the symlink components, but begin a new Continuation Area (CE) instead. This may waste some space, but the SunOS 4.1.4 cdrom driver has a bug in reading split symlink components.

It is questionable whether this option is useful nowadays. 🤷‍♀️

  • -no-split-symlink-fields — don't split the symlink fields, but begin a new Continuation Area (CE) instead. This may waste some space, but the SunOS 4.1.4 and Solaris 2.5.1 cdrom driver have a bug in reading split symlink fields (a / can be dropped).

It is questionable whether this option is useful nowadays. 🤷‍♀️

  • -o filename — specifies the output file for the the ISO9660 filesystem image. This can be a disk file, a tape drive, or it can correspond directly to the device name of the optical disc writer. If not specified, stdout is used. Note that the output can also be a block device for a regular disk partition, in which case the ISO9660 filesystem can be mounted normally to verify that it was generated correctly. ✨
  • -pad — bestie, this pads the end of the whole image by 150 sectors (300 kB). And it's on by default! 🎀 If you use it together with -B, the padding gets squeezed in between the ISO9660 partition and the boot partitions, so that the first boot partition starts on a sector number that's a multiple of 16.

Why do we even need padding? Because so many operating systems (looking at you, Linux 👀) have read-ahead bugs in their filesystem I/O. Those bugs cause read errors on files hanging out near the end of a track — especially if the disc is written in Track At Once mode, or when a CD audio track follows the data track. So yeah, padding is the vibe check that keeps your reads from flopping. 💅

  • -no-pad — nope, not doing it. This means don't pad the end by 150 sectors (300 kB), and also don't make the boot partitions start on a multiple of 16 sectors. 🙈
  • -path-list file — a file that holds a list of pathspec directories and filenames to add to the ISO9660 filesystem. These pathspecs get processed after any that show up on the command line. And if the argument is -, the list is read straight from the standard input. ✨
  • -P — outdated option, bestie, do not use it. Use -publisher instead. It's giving legacy energy. 💀
  • -publisher publisher_id — drops a text string into the volume header. This should describe the publisher of the CD-ROM — usually a mailing address and phone number, yk? There's space for 128 characters. Equivalent to PUBL in the .genisoimagerc file. 🌸
  • -p preparer_id — same energy but for the preparer of the CD-ROM, again usually with a mailing address and phone number. Space for 128 characters. Equivalent to PREP in the .genisoimagerc file. 🎀
  • -print-size — prints the estimated filesystem size in multiples of the sector size (2048 bytes) and then exits. This one's needed for Disk At Once mode and for some CD-R drives when you're piping directly into wodim — cases where wodim needs to know the size of the filesystem image in advance. Old versions of mkisofs wrote this info (among other stuff) to stderr, but that turned out to be a pain to parse, so now the number gets printed on stdout too, with no extra noise. Wanna write a simple shell script? Redirect stderr and catch the number from stdout, like this:
cdblocks=` genisoimage -print-size -quiet ... `
genisoimage ... | wodim ... tsize=${cdblocks}s -
  • -quiet — makes genisoimage even less verbose. No progress output will be provided. Silence. Iconic. 🤫
  • -R — generate SUSP and RR records using the Rock Ridge protocol to further describe the files on the ISO9660 filesystem. 🦋
  • -r — like -R, but the file ownership and modes get set to values that are actually useful. Let me break it down, bestie:
    • uid and gid are set to zero, because they're usually only useful on the author's system and not useful to the client.
    • All the file read bits are set true, so files and directories are globally readable on the client.
    • If any execute bit is set for a file, all of the execute bits get set, so executables are globally executable on the client.
    • If any search bit is set for a directory, all of the search bits get set, so directories are globally searchable on the client.
    • All write bits are cleared, because the filesystem is gonna be mounted read-only in any case.
    • If any of the special mode bits are set, they get cleared — because file locks aren't useful on a read-only filesystem, and set-id bits are not desirable for uid 0 or gid 0.

When used on Win32, the execute bit is set on all files. This is a result of the lack of file permissions on Win32 and the Cygwin POSIX emulation layer. See also -uid, -gid, -dir-mode, -file-mode and -new-dir-mode. 💖

  • -relaxed-filenames — allows ISO9660 filenames to include all 7-bit ASCII characters except lowercase letters. This violates the ISO9660 standard, but it happens to work on many systems. Use with caution, fr fr. ⚠️
  • -root dir — moves all files and directories into dir in the image. This is basically the same as using -graft-points and adding dir in front of every pathspec, but it's way easier to use. dir can actually be several levels deep. It gets created with the same permissions as other graft points. 🌈
  • -old-root dir — this one is necessary when you're writing a multisession image and the previous (or even older) session was written with -root dir. If you use a directory name that isn't found in the previous session, genisoimage aborts with an error. Without this option, genisoimage wouldn't be able to find unmodified files and would be forced to write their data into the image once more. -root and -old-root are meant to be used together for incremental backups. 💅

So like, the initial session would e.g. use: genisoimage -root backup_1 dirs. The next incremental backup with genisoimage -root backup_2 -old-root backup_1 dirs would take another snapshot of these directories. The first snapshot would be found in backup_1, the second one in backup_2, but only modified or new files need to be written into the second session. Without these options, new files would be added and old ones would be preserved — but old ones would be overwritten if the file was modified. And recovering the files by copying the whole directory back from CD would also restore files that were deleted intentionally. Accessing several older versions of a file requires support by the operating system to choose which sessions are to be mounted. 🫶

  • -sort sort_file — sorts file locations on the media. The sorting is controlled by a file containing pairs of filenames and sorting offset weighting. Higher weighting = file goes closer to the beginning of the media. Lower weighting = file goes closer to the end. There must be only one space or tabs character between the filename and the weight, and the weight must be the last characters on a line. The filename is taken to include all the characters up to, but not including, the last space or tab character on a line — this is to allow for space characters to be in, or at the end of, a filename.

Heads up: this option does not sort the order of the filenames that appear in the ISO9660 directory. It sorts the order in which the file data is written to the CD image, which is useful to optimize the data layout on a CD. See README.sort for more details. ⭐

  • -sparc-boot img_sun4,img_sun4c,img_sun4m,img_sun4d,img_sun4e — see -B above. 👑
  • -sparc-label label — sets the Sun disk label name for the Sun disk label that gets created with -sparc-boot. 🌞
  • -split-output — splits the output image into several files of approximately 1 GB each. This helps create DVD-sized ISO9660 images on operating systems without large file support. wodim will concatenate more than one file into a single track if writing to a DVD. To make -split-output work, -o filename must be specified. The resulting output images will be named: filename_00, filename_01, filename_02... 🍓
  • -stream-media-size # — selects streaming operation and sets the media size to # sectors. This lets you pipe the output of the tar(1) program into genisoimage and create an ISO9660 filesystem without needing an intermediate tar archive file. If this option has been specified, genisoimage reads from stdin and creates a file with the name STREAM.IMG. The maximum size of the file (with padding) is 200 sectors less than the specified media size. If -no-pad has been specified, the file size is 50 sectors less than the specified media size. If the file is smaller, genisoimage will write padding — and that may take awhile. 😭
The option -stream-media-size creates simple ISO9660 filesystems only and may not be used together with multisession or hybrid filesystem options.
  • -stream-file-name name — reserved for future use. Mysterious. We love a placeholder. 🙈
  • -sunx86-boot UFS_img,,,AUX1_img — specifies a comma-separated list of filesystem images that are needed to make a bootable CD for Solaris x86 systems. 🦋

Note that partition 1 is used for the ISO9660 image and that partition 2 is the whole disk, so partition 1 and 2 may not be used by external partition data. The first image file is mapped to partition 0. There may be empty fields in the comma-separated list, and list entries for partition 1 and 2 must be empty. The maximum number of supported partitions is 8 (although the Solaris x86 partition table could support up to 16 partitions), so it is impossible to specify more than 6 partition images. This option is required to make a bootable CD for Solaris x86 systems. 💅

If -sunx86-boot has been specified, the first sector of the resulting image will contain a PC fdisk label with a Solaris type 0x82 fdisk partition that starts at offset 512 and spans the whole CD. In addition, for the Solaris type 0x82 fdisk partition, there is a SVr4 disk label at offset 1024 in the first sector of the CD. This disk label specifies slice 0 for the first (usually UFS type) filesystem image that is used to boot the PC and slice 1 for the ISO9660 image. Slice 2 spans the whole CD, and slice 3 ... slice 7 may be used for additional filesystem images that have been specified with this option.

A Solaris x86 boot CD uses a 1024 byte sized primary boot that uses the El-Torito no-emulation boot mode and a secondary generic boot that is in CD sectors 1..15. For this reason, both -b bootimage -no-emul-boot and -G genboot must be specified. ✨

  • -sunx86-label label — sets the SVr4 disk label name for the SVr4 disk label that gets created with -sunx86-boot. 🌸
  • -sysid ID — specifies the system ID. There's space for 32 characters. Equivalent to SYSI in the .genisoimagerc file. 💜
  • -T — bestie this one makes a file called TRANS.TBL in every single directory on the CD-ROM 💅 and its whole job is helping out the non-Rock Ridge-capable systems so they can figure out the correct filenames. There's also info in that file showing the major and minor numbers for block and character devices, and every symlink gets the name of the link file written in there too. So thoughtful of it honestly.
  • -table-name table_name — picks a different translation table filename (see above, queen). Fun fact: this implies -T. And if you're making a multisession image you must use the same name as in the previous session — no cap, no exceptions.
  • -ucs-level level — sets the Unicode conformance level in the Joliet SVD. Default is 3 ✨ and you can set it to 1..3 with this option.
  • -udf — adds UDF filesystem support into the generated filesystem image. Okay but listen: UDF support is currently in alpha status 😭 and because of that it is not possible to create UDF-only images. The UDF data structures are currently coupled to the Joliet structures, so there are many pitfalls with the current implementation. And it gets worse, bestie — there is no UID/GID support, there is no POSIX permission support, and there is no support for symlinks. Also heads up: UDF wastes the space from sector ~20 to sector 256 at the beginning of the disc, on top of the space needed for the real UDF data structures. It's giving space-hungry 🫠
  • -uid uid — overrides the uid read from the source files, setting it to the value of uid. And specifying this option automatically enables Rock Ridge extensions, so it's a two-for-one, slay.
  • -use-fileversion — lets genisoimage use file version numbers from the filesystem. If you don't specify it, genisoimage creates a version number of 1 for all files. File versions are strings in the range ;1 to ;32767. Also this option is the default on VMS 🌈
  • -U — allows "untranslated" filenames, which completely violates the ISO9660 standards described above 😳 It enables the following flags: -d -l -N -allow-leading-dots -relaxed-filenames -allow-lowercase -allow-multidot -no-iso-translate. It allows more than one . character in the filename, plus mixed-case filenames. Genuinely useful on HP-UX, where the built-in cdfs filesystem does not recognize any extensions. > Use with extreme caution. Not me warning you twice.
  • -no-iso-translate — does not translate the characters # and ~, which are invalid for ISO9660 filenames. Even though they're invalid, these characters are often used by Microsoft systems 🙈 This violates the ISO9660 standard, but it happens to work on many systems. > Use with caution.
  • -V volid — specifies the volume ID (aka the volume name or label) that gets written into the master block. There's space for 32 characters. Equivalent to VOLI in the .genisoimagerc file. The volume ID is used as the mount point by the Solaris volume manager, and as a label assigned to a disc on various other platforms like Windows and Apple Mac OS. She's multi-platform 💖
  • -volset ID — specifies the volume set ID. There's space for 128 characters. Equivalent to VOLS in the .genisoimagerc file.
  • -volset-size # — sets the volume set size to #. The volume set size is the number of CDs that are in a CD volume set. A volume set is a collection of one or more volumes, on which a set of files is recorded.

Okay real talk, listen up: Volume Sets are not intended to be used to create a set of numbered CDs that are part of, like, an Operation System installation set of CDs. Volume Sets are rather used to record a big directory tree that would not fit on a single volume. Each volume of a Volume Set contains a description of all the directories and files that are recorded on the volumes where the sequence numbers are less than, or equal to, the assigned Volume Set Size of the current volume.

And here's the tea 🍵 genisoimage currently does not support a -volset-size that is larger than 1.

The option -volset-size must be specified before -volset-seqno on each command line. Order matters, bestie, always has.
  • -volset-seqno # — sets the volume set sequence number to #. The volume set sequence number is the index number of the current CD in a CD set. > The option -volset-size must be specified before -volset-seqno on each command line. (Yes we said it again. It's that serious.)
  • -v — verbose execution 👑 If given twice on the command line, extra debug information will be printed. Double it and the lore gets deeper.
  • -x glob — identical to -m glob. Literally the same thing, just a different name.
  • -z — generates special RRIP records for transparently compressed files 🦋 This is only of use and interest for hosts that support transparent decompression, such as Linux 2.4.14 or later. You must specify -R or -r to enable Rock Ridge, and generate compressed files using the mkzftree utility before running genisoimage. Note that transparent compression is a nonstandard Rock Ridge extension, so the resulting disks are only transparently readable if used on Linux. On other operating systems you will need to call mkzftree by hand to decompress the files. Sorry to the non-Linux girlies 😔

✨ HFS OPTIONS ✨

okay bestie, buckle up, this is the Mac-flavoured corner of genisoimage and it's a LOT. but we're gonna go through every single one, no skipping, fr fr 🍓

  • -hfs — makes an ISO9660/HFS hybrid CD. the vibes: one disc, two filesystems, both iconic. you're supposed to pair this with -map, -magic and/or the various double dash options listed further down. it's giving teamwork 💅
  • -apple — makes an ISO9660 CD with Apple's extensions. similar to -hfs, except instead of building a whole HFS hybrid volume, it just adds the Apple Extensions to ISO9660. important lore: old genisoimage versions used to sneak Rock Ridge attributes in by default when you said -apple, but this version does not do that anymore. if you want Rock Ridge attributes, you have to ask for them separately. no freebies 🎀
  • -map mapping_file — use mapping_file to set the CREATOR and TYPE info for a file based on the filename's extension. a filename only gets mapped if it's not one of the known Apple/Unix file formats. peep the HFS CREATOR/TYPE section below for the tea.
  • -magic magic_file — sets CREATOR and TYPE info using a file's magic number (usually the first few bytes of a file, iykyk 🔮). magic_file only gets used if the file isn't one of the known Apple/Unix file formats, or if the filename extension hasn't already been mapped with -map. again, HFS CREATOR/TYPE section below has more details.
  • -hfs-creator creator — sets the default CREATOR for all files. has to be exactly 4 characters, no more no less, not negotiable 😤. see the HFS CREATOR/TYPE section below.
  • -hfs-type type — sets the default TYPE for all files. also must be exactly 4 characters. see HFS CREATOR/TYPE below.
  • -probe — searches the contents of files for all the known Apple/Unix file formats. see the HFS MACINTOSH FILE FORMATS section below for more about those formats. heads up though: the only way to check for MacBinary and AppleSingle files is to actually open and read them, so this option can make processing take longer. it's better to use one or more of the double dash options below if you already know which Apple/Unix formats are in play. work smarter not harder ✨
  • -no-desktop — don't create (empty) Desktop files. new HFS Desktop files will get created when the CD is used on a Macintosh (and stored in the System Folder). by default, empty Desktop files are added to the HFS volume. so this is you opting out of the default.
  • -mac-name — uses the HFS filename as the starting point for the ISO9660, Joliet and Rock Ridge filenames. see the HFS MACINTOSH FILENAMES section below for more.
  • -boot-hfs-file driver_file — installs the driver_file that may make the CD bootable on a Macintosh. see the HFS BOOT DRIVER section below. (Alpha).
  • -part — generates an HFS partition table. by default no partition table is generated, but some older Macintosh CD-ROM drivers genuinely need one on the CD-ROM to even recognize a hybrid CD-ROM. legacy king behavior tbh 👑
  • -auto AutoStart_file — makes the HFS CD use the QuickTime 2.0 Autostart feature to launch an application or document. the filename you give has to be the name of a document or application sitting at the top level of the CD, and it must be less than 12 characters. (Alpha).
  • -cluster-size size — sets the size in bytes of the cluster or allocation units of PC Exchange files. implies --exchange. see the HFS MACINTOSH FILE FORMATS section below.
  • -hide-hfs glob — hides glob, a shell wildcard pattern, from the HFS volume. the file or directory will still exist in the ISO9660 and/or Joliet directory, it's just invisible to HFS. glob can match any part of the filename, and you can exclude multiple globs. example:
genisoimage -o rom -hfs -hide-hfs '*.o' -hide-hfs foobar

that would exclude all files ending in `.o' or called foobar from the HFS volume. note: if you had a directory called foobar, it too (and of course all its descendants) would be excluded. 💀

the glob can also be a path name relative to the source directories given on the command line. example:

genisoimage -o rom -hfs -hide-hfs src/html src

that would exclude just the file or directory called html from the src directory. any other file or directory called html elsewhere in the tree will not be excluded. should be used with -hide and/or -hide-joliet. and in order to match a directory name, make sure your pattern does not include a trailing `/' character. see README.hide for more details. 🫶

  • -hide-hfs-list file — specify a file containing a list of wildcard patterns to be hidden, same energy as -hide-hfs.
  • -hfs-volid hfs_volid — volume name for the HFS partition. this is the name that gets assigned to the disc on a Macintosh, and it replaces the volid used with -V. naming rights, iconic.
  • -icon-position — uses the icon position information, if it exists, from the Apple/Unix file. the icons will show up in the same position as they would on a Macintosh desktop. folder location and size on screen, its scroll positions, folder View (view as Icons, Small Icons, etc.) are all preserved too. (Alpha). ✨
  • -root-info file — sets the location, size on screen, scroll positions, folder View etc. for the root folder of an HFS volume. see README.rootinfo for more information. (Alpha)
  • -prep-boot file — PReP boot image file. up to 4 are allowed. see README.prep_boot for more information. (Alpha)
  • -chrp-boot — adds a CHRP boot header.
  • -input-hfs-charset charset — input charset that defines the characters used in HFS filenames when used with -mac-name. the default charset is cp10000 (Mac Roman). see the CHARACTER SETS and HFS MACINTOSH FILENAMES sections below for more details.
  • -output-hfs-charset charset — output charset that defines the characters that will be used in the HFS filenames. defaults to the input charset. see the CHARACTER SETS section below for more details.
  • -hfs-unlock — by default, genisoimage creates an HFS volume that is locked. this option leaves the volume unlocked so other applications (e.g. hfsutils) can modify the volume. see the HFS PROBLEMS/LIMITATIONS section below for the warnings about using this option. read those warnings bestie, pls 🙈
  • -hfs-bless folder_name — "Bless" the given directory (folder). this is usually the System Folder and it's used in creating HFS bootable CDs. the name of the directory must be the whole path name as genisoimage sees it. e.g., if the given pathspec is ./cddata and the required folder is called System Folder, the whole path name is "/cddata/System Folder" (remember to use quotes if the name contains spaces). 🎀
  • -hfs-parms parameters — override certain parameters used to create the HFS filesystem. unlikely to be used in normal circumstances. see the libhfs_iso/hybrid.h source file for details. deep lore territory, only for the brave.

okay now the double dash squad — these are the "which Apple/Unix format should I even be looking for" toggles. all vibes, all specific 💅

  • --cap — look for AUFS CAP Macintosh files. searches for CAP Apple/Unix file formats only. searching for the other possible Apple/Unix file formats is disabled, unless other double dash options are given.
  • --netatalk — look for NETATALK Macintosh files
  • --double — look for AppleDouble Macintosh files
  • --ethershare — look for Helios EtherShare Macintosh files
  • --ushare — look for IPT UShare Macintosh files
  • --exchange — look for PC Exchange Macintosh files
  • --sgi — look for SGI Macintosh files
  • --xinet — look for XINET Macintosh files
  • --macbin — look for MacBinary Macintosh files
  • --single — look for AppleSingle Macintosh files
  • --dave — look for Thursby Software Systems DAVE Macintosh files
  • --sfm — look for Microsoft's Services for Macintosh files (NT only) (Alpha)
  • --osx-double — look for Mac OS X AppleDouble Macintosh files
  • --osx-hfs — look for Mac OS X HFS Macintosh files

every single one accounted for, no cap 🌈

✨ CHARACTER SETS ✨

okay bestie, this section is the ✨drama✨ of filename encoding and honestly? it's giving "why is everything on fire" 🔥. buckle up.

so, genisoimage handles filenames in a POSIX-compliant way — as strings of 8-bit characters. cute, right? except that 8-bit characters are not enough to represent all the codings for all the languages 💀. like, Unicode / ISO-10646 define character codings that need at least 21 bits to represent every known language. they can be represented with UTF-32, UTF-16 or UTF-8 coding. UTF-32 uses a plain 32-bit coding but is lowkey uncommon. UTF-16 is what Microsoft uses with Win32, and the downside there is that 16-bit characters are not compliant with the POSIX filesystem interface 😭.

modern Unix operating systems may use UTF-8 coding for filenames. each 32-bit character is represented by one or more 8-bit characters. if a character is coded in ISO-8859-1 (used in Central Europe and North America) it maps 1:1 to a UTF-32 or UTF-16 coded Unicode character. if a character is coded in 7-Bit ASCII (used in USA and other countries with a limited character set) it maps 1:1 to a UTF-32, UTF-16 or UTF-8 coded Unicode character. character codes that can't be represented as a single byte in UTF-8 (if the value is > 0x7F) use escape sequences that map to more than one 8-bit character. iykyk ✨

if all operating systems used UTF-8, genisoimage wouldn't even need to recode characters in filenames. unfortunately 💅, Apple uses completely nonstandard codings and Microsoft uses a Unicode coding that is not compatible with the POSIX filename interface. so here we are.

for all non-UTF-8-coded operating systems, the actual character that each byte represents depends on the character set — or codepage, which is what Microsoft calls it — used by the local operating system. the characters in a character set will reflect the region or natural language set by the user 🌍.

usually character codes 0x00-0x1f are control characters, codes 0x20-0x7f are the 7-bit ASCII characters and (on PCs and Macs) 0x80-0xff are used for other characters.

since there are a lot more than 256 characters/symbols in use, only a small subset is represented in a character set. therefore the same character code may represent a different character in different character sets 😵. so a filename generated, say, in central Europe may not display the same character when viewed on a machine in, say, eastern Europe.

and to make matters more complicated 🫠, different operating systems use different character sets for the region or language. for example, the character code for é (small e with acute accent) may be character code 0x82 on a PC, code 0x8e on a Macintosh, code 0xe9 on a Unix system in western Europe, and code 0x000e9 in Unicode. literally a whole identity crisis for one little letter.

as long as not all operating systems and applications use the same character set as the basis for filenames, it may be necessary to specify which character set your filenames use in, and which character set the filenames should appear on the CD. soooo:

there are four options to specify the character sets you want to use:

  • -input-charset — defines the local character set you're using on your host machine. any character set conversions that take place will use this character set as the starting point. the default input character sets are cp437 on MS-DOS-based systems and iso8859-1 on all other systems. if -J is given, the Unicode equivalents of the input character set will be used in the Joliet directory. -jcharset is the same as -input-charset -J 💖
  • -output-charset — defines the character set that will be used with for the Rock Ridge names on the CD. defaults to the input character set.
  • -input-hfs-charset — defines the HFS character set used for HFS filenames decoded from any of the various Apple/Unix file formats. only useful when used with -mac-name. see the HFS MACINTOSH FILENAMES section for more info. defaults to cp10000 (Mac Roman).
  • -output-hfs-charset — defines the HFS character set used to create HFS filenames from the input character set in use. in most cases this will be from the character set given with -input-charset. defaults to the input HFS character set.

there are a number of character sets built in to genisoimage. to get a listing, use -input-charset help 👑. this list doesn't include the charset derived from the current locale, if genisoimage is built with iconv support.

additional character sets can be read from file for any of the character set options by giving a filename as the argument to the options. the given file will only be read if its name does not match one of the built-in character sets.

the format of the character set files is the same as the mapping files available from http://www.unicode.org/Public/MAPPINGS. this format is:

       Column #1 is the input byte code (in hex as 0xXX)
       Column #2 is the Unicode (in hex as 0xXXXX)
       The rest of the line is ignored.

any blank line, line without two (or more) columns in the above format, or comments lines (starting with the # character) are ignored without any warnings. any missing input code is mapped to Unicode character 0x0000.

ngl, quick reality check bestie: while UTF-8 is supported, other Unicode encodings such as UCS-2/UTF-16 and UCS-4/UTF-32 are not, because POSIX operating systems cannot handle them natively. no cap.

a 1:1 character set mapping can be defined by using the keyword default as the argument to any of the character set options. this is the behaviour of old versions of mkisofs.

the ISO9660 filenames generated from the input filenames are not converted from the input character set. the ISO9660 character set is a very limited subset of the ASCII characters, so any conversion would be pointless. periodt.

any character that genisoimage cannot convert will be replaced with a _ character. 💀

🍎 HFS CREATOR/TYPE 🍎

a Macintosh file has two properties associated with it which define which application created the file — the CREATOR — and what data the file contains — the TYPE. both are (exactly) 4 letter strings. usually this lets a Macintosh user double-click on a file and launch the correct application etc. the CREATOR and TYPE of a particular file can be found by using something like ResEdit (or similar) on a Macintosh.

the CREATOR and TYPE information is stored in all the various Apple/Unix encoded files. for other files it's possible to base the CREATOR and TYPE on the filename's extension using a mapping file (with -map) and/or using the magic number (usually a signature in the first few bytes) of a file (with -magic). if both these options are given, their order on the command line is significant 👀. if -map is given first, a filename extension match is attempted before a magic number match. however, if -magic is given first, a magic number match is attempted before a filename extension match.

if a mapping or magic file is not used, or no match is found, the default CREATOR and TYPE for all regular files can be set by using entries in the .genisoimagerc file or using -hfs-creator and/or -hfs-type, otherwise the default CREATOR and TYPE are Unix and TEXT.

the mapping file 💅

the format of the mapping file is the same afpfile format as used by aufs. this file has five columns for the extension, file translation, CREATOR, TYPE and Comment. lines starting with the # character are comment lines and are ignored. an example file would be like:

       # Example filename mapping file
       #
       # EXTN   XLate   CREATOR   TYPE     Comment
       .tif     Raw     '8BIM'    'TIFF'   "Photoshop TIFF image"
       .hqx     Ascii   'BnHq'    'TEXT'   "BinHex file"
       .doc     Raw     'MSWD'    'WDBN'   "Word file"
       .mov     Raw     'TVOD'    'MooV'   "QuickTime Movie"
       *        Ascii   'ttxt'    'TEXT'   "Text file"

where:

  • the first column EXTN defines the Unix filename extension to be mapped. the default mapping for any filename extension that doesn't match is defined with the * character.
  • the Xlate column defines the type of text translation between the Unix and Macintosh file. it is ignored by genisoimage, but is kept to be compatible with aufs(1). although genisoimage does not alter the contents of a file, if a binary file has its TYPE set as TEXT, it may be read incorrectly on a Macintosh. therefore a better choice for the default TYPE may be ????. 🙈
  • the CREATOR and TYPE keywords must be 4 characters long and enclosed in single quotes.
  • the comment field is enclosed in double quotes — it is ignored by genisoimage, but is kept to be compatible with aufs.

the magic file ✨

the format of the magic file is almost identical to the magic(5) file used by the file(1) command.

this file has four tab-separated columns for the byte offset, type, test and message. lines starting with the # character are comment lines and are ignored. an example file would be like:

       # Example magic file
       #
       # off   type      test       message
       0       string    GIF8       8BIM GIFf  GIF image
       0       beshort   0xffd8     8BIM JPEG  image data
       0       string    SIT!       SIT! SIT!  StuffIt Archive
       0       string    \037\235   LZIV ZIVU  standard Unix compress
       0       string    \037\213   GNUz ZIVU  gzip compressed data
       0       string    %!         ASPS TEXT  Postscript
       0       string    \004%!     ASPS TEXT  PC Postscript with a ^D to start
       4       string    moov       txtt MooV  QuickTime movie file (moov)
       4       string    mdat       txtt MooV  QuickTime movie file (mdat)

the format of the file is described in magic(5). the only difference here is that for each entry in the magic file, the message for the initial offset must be be 4 characters for the CREATOR followed by 4 characters for the TYPE — white space is optional between them. any other characters on this line are ignored. continuation lines (starting with a >) are also ignored, i.e., only the initial offset lines are used.

heads up bestie: using -magic may significantly increase processing time as each file has to be opened and read to find its magic number. ⏳

so, in summary 🌸

for all files, the default CREATOR is Unix and the default TYPE is TEXT. these can be changed by using entries in the .genisoimagerc file or by using -hfs-creator and/or -hfs-type.

if the a file is in one of the known Apple/Unix formats (and the format has been selected), the CREATOR and TYPE are taken from the values stored in the Apple/Unix file.

other files can have their CREATOR and TYPE set from their filename extension (with -map), or their magic number (with -magic). if the default match is used in the mapping file, these values override the default CREATOR and TYPE.

a full CREATOR/TYPE database can be found at http://www.angelfire.com/il/szekely/. 🦋 go get your icon fix, bestie.

🌸 HFS MACINTOSH FILE FORMATS 🌸

okay bestie, here's the tea on Macintosh files 🫖 — they have two parts called the Data and Resource fork. Either one can be empty, no drama. But here's the thing: Unix (and honestly most other OSs) can only deal with files that have one part (or fork). And it gets worse — Macintosh files also carry a bunch of attributes with them, and the ones that really matter are the TYPE and CREATOR. Unix has zero concept of these attribute situations. 💀

so like, a Macintosh file could be a JPEG image where the actual image lives in the Data fork and a desktop thumbnail lives in the Resource fork. Usually it's the data fork info that's useful across platforms, iykyk.

so to store a Macintosh file on a Unix filesystem, somebody had to figure out how to handle both forks and the extra attributes (which we call the Finder info). And the tragedy? 😭 Every single software package that stores Macintosh files on Unix picked a completely different storage method. iconic of them honestly.

The Apple/Unix formats that genisoimage (partially) supports are:

  • CAP AUFS format — Data fork stored in a file. Resource fork in subdirectory .resource with same filename as data fork. Finder info in subdirectory .finderinfo with same filename.
  • AppleDouble/Netatalk — Data fork stored in a file. Resource fork stored in a file with same name prefixed with %. Finder info also stored in same % file. Netatalk uses the same format, but the resource fork/Finder info stored in subdirectory .AppleDouble with same filename as data fork.
  • AppleSingle — Data structures similar to above, except both forks and Finder info are stored in one file.
  • Helios EtherShare — Data fork stored in a file. Resource fork and Finder info together in subdirectory .rsrc with same filename as data fork.
  • IPT UShare — Like the EtherShare format, but the Finder info is stored slightly differently.
  • MacBinary — Both forks and Finder info stored in one file.
  • Apple PC Exchange — Used by Macintoshes to store Apple files on DOS (FAT) disks. Data fork stored in a file. Resource fork in subdirectory resource.frk (or RESOURCE.FRK). Finder info as one record in file finder.dat (or FINDER.DAT). Separate finder.dat for each data fork directory.
Note: genisoimage needs to know the native FAT cluster size of the disk that the PC Exchange files are on (or have been copied from). This size is given by -cluster-size. The cluster or allocation size can be found by using the DOS utility chkdsk.
May not work with PC Exchange v2.2 or higher files (available with MacOS 8.1). DOS media containing PC Exchange files should be mounted as type msdos (not vfat) when using Linux.
  • SGI/XINET — Used by SGI machines when they mount HFS disks. Data fork stored in a file. Resource fork in subdirectory .HSResource with same filename. Finder info as one record in file .HSancillary. Separate .HSancillary for each data fork directory.
  • Thursby Software Systems DAVE — Allows Macintoshes to store Apple files on SMB servers. Data fork stored in a file. Resource fork in subdirectory resource.frk. Uses the AppleDouble format to store resource fork.
  • Services for Macintosh — Format of files stored by NT Servers on NTFS filesystems. Data fork is stored as filename. Resource fork stored as a NTFS stream called filename:AFP_Resource. The Finder info is stored as a NTFS stream called filename:Afp_AfpInfo. NTFS streams are normally invisible to the user.
Warning: genisoimage only partially supports the SFM format. If an HFS file or folder stored on the NT server contains an illegal NT character in its name, NT converts these characters to Private Use Unicode characters. The characters are: " * / < > ? \ | and a space or period if it is the last character of the filename, character codes 0x01 to 0x1f (control characters) and Apple's apple logo.
Unfortunately, these private Unicode characters are not readable by the genisoimage NT executable. Therefore any file or directory name containing these characters will be ignored — including the contents of any such directory. 🙈
  • Mac OS X AppleDouble — When HFS/HFS+ files are copied or saved by Mac OS X on to a non-HFS filesystem (e.g. UFS, NFS etc.), the files are stored in AppleDouble format. Data fork stored in a file. Resource fork stored in a file with same name prefixed with ._. Finder info also stored in same ._ file.
  • Mac OS X HFS (Alpha) — Not really an Apple/Unix encoding, but actual HFS/HFS+ files on a Mac OS X system. Data fork stored in a file. Resource fork stored in a pseudo file with the same name with the suffix /rsrc. The Finder info is only available via a Mac OS X library call.
    • See also README.macosx.
    • Only works when used on Mac OS X.
    • If a file is found with a zero length resource fork and empty finderinfo, it is assumed not to have any Apple/Unix encoding — therefore a TYPE and CREATOR can be set using other methods.

genisoimage will attempt to set the CREATOR, TYPE, date and possibly other flags from the finder info. Plus, if it exists, the Macintosh filename is set from the finder info — otherwise the Macintosh name is based on the Unix filename — see the HFS MACINTOSH FILENAMES section below. 👑

When using -apple, the TYPE and CREATOR are stored in the optional System Use or SUSP field in the ISO9660 Directory Record — in much the same way as the Rock Ridge attributes are. And honestly to make life easy, the Apple extensions are added at the beginning of the existing Rock Ridge attributes (i.e., to get the Apple extensions you get the Rock Ridge extensions as well). package deal bestie 🎀

The Apple extensions require the resource fork to be stored as an ISO9660 associated file. This is just like any normal file stored in the ISO9660 filesystem except that the associated file flag is set in the Directory Record (bit 2). This file has the same name as the data fork (the file seen by non-Apple machines). Associated files are normally ignored by other OSs.

When using -hfs, the TYPE and CREATOR plus other finder info, are stored in a separate HFS directory, not visible on the ISO9660 volume. The HFS directory references the same data and resource fork files described above.

In most cases, it is better to use -hfs instead of -apple, as the latter imposes the limited ISO9660 characters allowed in filenames. However, the Apple extensions do give the advantage that the files are packed on the disk more efficiently and it may be possible to fit more files on a CD. ✨

🦋 HFS MACINTOSH FILENAMES 🦋

Where possible, the HFS filename that is stored with an Apple/Unix file is used for the HFS part of the CD. However, not all the Apple/Unix encodings store the HFS filename with the finderinfo. In these cases, the Unix filename is used — with escaped special characters. Special characters include / and characters with codes over 127.

AUFS escapes these characters by using : followed by the character code as two hex digits. Netatalk and EtherShare have a similar scheme, but uses % instead of a :.

If genisoimage cannot find an HFS filename, it uses the Unix name, with any %xx or :xx characters (xx are two hex digits) converted to a single character code. If xx are not hex digits ([0-9a-fA-F]), they are left alone — although any remaining : is converted to %, as : is the HFS directory separator. Care must be taken, as an ordinary Unix file with %xx or :xx will also be converted. e.g.

This:2fFile   converted to This/File

This:File     converted to This%File

This:t7File   converted to This%t7File

Although HFS filenames appear to support uppercase and lowercase letters, the filesystem is case-insensitive, i.e., the filenames aBc and AbC are the same. If a file is found in a directory with the same HFS name, genisoimage will attempt to make a unique name by adding _ characters to one of the filenames.

If an HFS filename exists for a file, genisoimage can use this name as the starting point for the ISO9660, Joliet and Rock Ridge filenames using -mac-name. Normal Unix files without an HFS name will still use their Unix name. e.g.

If a MacBinary (or PC Exchange) file is stored as someimage.gif.bin on the Unix filesystem, but contains a HFS file called someimage.gif, this is the name that would appear on the HFS part of the CD. However, as genisoimage uses the Unix name as the starting point for the other names, the ISO9660 name generated will probably be SOMEIMAG.BIN and the Joliet/Rock Ridge would be someimage.gif.bin. This option will use the HFS filename as the starting point and the ISO9660 name will probably be SOMEIMAG.GIF and the Joliet/Rock Ridge would be someimage.gif. 💅

-mac-name will not currently work with -T — the Unix name will be used in the TRANS.TBL file, not the Macintosh name.

The character set used to convert any HFS filename to a Joliet/Rock Ridge filename defaults to cp10000 (Mac Roman). The character set used can be specified using -input-hfs-charset. Other built-in HFS character sets are: cp10006 (MacGreek), cp10007 (MacCyrillic), cp10029 (MacLatin2), cp10079 (MacIcelandandic) and cp10081 (MacTurkish).

Note: the character codes used by HFS filenames taken from the various Apple/Unix formats will not be converted as they are assumed to be in the correct Apple character set. Only the Joliet/Rock Ridge names derived from the HFS filenames will be converted.

The existing genisoimage code will filter out any illegal characters for the ISO9660 and Joliet filenames, but as genisoimage expects to be dealing directly with Unix names, it leaves the Rock Ridge names as is. But as / is a legal HFS filename character, -mac-name converts / to a _ in Rock Ridge filenames.

If the Apple extensions are used, only the ISO9660 filenames will appear on the Macintosh. However, as the Macintosh ISO9660 drivers can use Level 2 filenames, you can use options like -allow-multidot without problems on a Macintosh — still take care over the names, for example this.file.name will be converted to THIS.FILE i.e. only have one ., also filename abcdefgh will be seen as ABCDEFGH but abcdefghi will be seen as ABCDEFGHI. i.e. with a . at the end — don't know if this is a Macintosh problem or a genisoimage/mkhybrid problem. All filenames will be in uppercase when viewed on a Macintosh. Of course, DOS/Win3.X machines will not be able to see Level 2 filenames... 😭

💖 HFS CUSTOM VOLUME/FOLDER ICONS 💖

Okay so bestie, you want your HFS CD to have a cute custom icon? Here's the tea ☕ — the root (top level) folder has to include a standard Macintosh volume icon file. That's the whole vibe.

To give a volume a custom icon on a Macintosh, an icon has to be pasted over the volume's icon in the "Get Info" box of the volume. Doing that creates an invisible file called Icon\r in the root folder — and yes, that \r is literally the carriage return character, she's in the filename, no cap. 🙈

A custom folder icon is very similar — an invisible file called Icon\r exists in the folder itself.

Probably the easiest way to create a custom icon that genisoimage can use is to format a blank HFS floppy disk on a Mac and paste an icon to its "Get Info" box. If you're on Linux with the HFS module installed, mount the floppy like:

mount -t hfs /dev/fd0 /mnt/floppy

The floppy will be mounted as a CAP filesystem by default. Then run genisoimage using something like:

genisoimage --cap -o output source_dir /mnt/floppy

If you are not using Linux, you can use hfsutils to copy the icon file from the floppy. However, care has to be taken, as the icon file contains a control character. For example:

hmount /dev/fd0
hdir -a
hcopy -m Icon^V^M icon_dir/icon

Where ^V^M is control-V followed by control-M. (Yeah girl, you literally type control-V then control-M, it's giving chaotic but it works.) Then run genisoimage by using something like:

genisoimage --macbin -o output source_dir icon_dir

The procedure for creating/using custom folder icons is very similar — paste an icon to folder's "Get Info" box and transfer the resulting Icon\r file to the relevant directory in the genisoimage source tree.

You may want to hide the icon files from the ISO9660 and Joliet trees. 👀

To give a custom icon to a Joliet CD, follow the instructions found at http://www.cdrfaq.org/faq03.html#S3-21-1.

🔥 HFS BOOT DRIVER 🔥

It may be possible to make the hybrid CD bootable on a Macintosh. (Not guaranteed, just possible — manifesting it fr fr.)

A bootable HFS CD requires an Apple CD-ROM (or compatible) driver, a bootable HFS partition and the necessary System, Finder, etc. files.

A driver can be obtained from any other Macintosh bootable CD-ROM using the apple_driver utility. This file can then be used with -boot-hfs-file.

The HFS partition (i.e. the hybrid disk in our case) must contain a suitable System Folder, again from another CD-ROM or disk.

For a partition to be bootable, it must have its boot block set. The boot block is in the first two blocks of a partition. For a non-bootable partition the boot block is full of zeros. Normally, when a System file is copied to partition on a Macintosh disk, the boot block is filled with a number of required settings — unfortunately I don't know the full spec for the boot block, so I'm guessing that the following will work. 😭

Therefore, the utility apple_driver also extracts the boot block from the first HFS partition it finds on the given CD-ROM and this is used for the HFS partition created by genisoimage.

Please note: By using a driver from an Apple CD and copying Apple software to your CD, you become liable to obey Apple Computer, Inc. Software License Agreements. ⚠️ (Legal girlies, read up — this one's on you.)

✨ EL TORITO BOOT INFORMATION TABLE ✨

When -boot-info-table is given, genisoimage will modify the boot file specified by -b by inserting a 56-byte boot information table at offset 8 in the file. This modification is done in the source filesystem, so make sure you use a copy if this file is not easily recreated! This file contains pointers which may not be easily or reliably obtained at boot time.

The format of this table is as follows; all integers are in section 7.3.1 ("little endian") format.

  Offset    Name           Size      Meaning
   8         bi_pvd         4 bytes   LBA of primary volume descriptor
  12         bi_file        4 bytes   LBA of boot file
  16         bi_length      4 bytes   Boot file length in bytes
  20         bi_csum        4 bytes   32-bit checksum
  24         bi_reserved    40 bytes  Reserved

The 32-bit checksum is the sum of all the 32-bit words in the boot file starting at byte offset 64. All linear block addresses (LBAs) are given in CD sectors (normally 2048 bytes).

🌈 HPPA NOTES 🌈

To make a bootable CD for HPPA, at the very least a boot loader file (-hppa-bootloader), a kernel image file (32-bit, 64-bit, or both, depending on hardware) and a boot command line (-hppa-cmdline) must be specified. Some systems can boot either a 32- or a 64-bit kernel, and the firmware will choose one if both are present. Optionally, a ramdisk can be used for the root filesystem using -hppa-cmdline. 💅

🦋 JIGDO NOTES 🦋

Jigdo is a tool to help in the distribution of large files like CD and DVD images; see http://atterer.org/jigdo/ for more details. Debian CDs and DVD ISO images are published on the web in jigdo format to allow end users to download them more efficiently. (Efficiency queen behavior 👑)

To create jigdo and template files alongside the ISO image from genisoimage, you must first generate a list of the files that will be used, in the following format:

  MD5sum   File size  Path
  32 chars 12 chars   to end of line

The MD5sum must be written in standard hexadecimal notation, the file size must list the size of the file in bytes, and the path must list the absolute path to the file. For example:

00006dcd58ff0756c36d2efae21be376         14736  /mirror/debian/file1
000635c69b254a1be8badcec3a8d05c1        211822  /mirror/debian/file2
00083436a3899a09633fc1026ef1e66e         22762  /mirror/debian/file3

Once you have this file, call genisoimage with all of your normal command-line parameters. Specify the output filenames for the jigdo and template files using -jigdo-jigdo and -jigdo-template, and pass in the location of your MD5 list with -md5-list.

If there are files that you do NOT want to be added into the jigdo file (e.g. if they are likely to change often), specify them using -jigdo-exclude. If you want to verify some of the files as they are written into the image, specify them using -jigdo-force-md5. If any files don't match, genisoimage will then abort. 😱 Both of these options take regular expressions as input. It is possible to restrict the set of files that will be used further based on size — use the -jigdo-min-file-size option.

Finally, the jigdo code needs to know how to map the files it is given onto a mirror-style configuration. Specify how to map paths using -jigdo-map. Using Debian=/mirror/debian will cause all paths starting with /mirror/debian to be mapped to Debian:<file> in the output jigdo file.

🎀 EXAMPLES 🎀

To create a vanilla ISO9660 filesystem image in the file cd.iso, where the directory cd_dir will become the root directory of the CD, call:

% genisoimage -o cd.iso cd_dir

To create a CD with Rock Ridge extensions of the source directory cd_dir:

% genisoimage -o cd.iso -R cd_dir

To create a CD with Rock Ridge extensions of the source directory cd_dir where all files have at least read permission and all files are owned by root, call:

% genisoimage -o cd.iso -r cd_dir

To write a tar archive directly to a CD that will later contain a simple ISO9660 filesystem with the tar archive call:

% tar cf - . | genisoimage -stream-media-size 333000 | \
     wodim dev=b,t,l -dao tsize=333000s -

To create a HFS hybrid CD with the Joliet and Rock Ridge extensions of the source directory cd_dir:

% genisoimage -o cd.iso -R -J -hfs cd_dir

To create a HFS hybrid CD from the source directory cd_dir that contains Netatalk Apple/Unix files:

% genisoimage -o cd.iso --netatalk cd_dir

To create a HFS hybrid CD from the source directory cd_dir, giving all files CREATOR and TYPES based on just their filename extensions listed in the file mapping.:

% genisoimage -o cd.iso -map mapping cd_dir

To create a CD with the Apple Extensions to ISO9660, from the source directories cd_dir and another_dir. Files in all the known Apple/Unix format are decoded and any other files are given CREATOR and TYPE based on their magic number given in the file magic:

% genisoimage -o cd.iso -apple -magic magic -probe \
        cd_dir another_dir

The following example puts different files on the CD that all have the name README, but have different contents when seen as a ISO9660/Rock Ridge, Joliet or HFS CD.

Current directory contains:

% ls -F
README.hfs     README.joliet  README.Unix    cd_dir/

The following command puts the contents of the directory cd_dir on the CD along with the three README files — but only one will be seen from each of the three filesystems:

% genisoimage -o cd.iso -hfs -J -r -graft-points \
        -hide README.hfs -hide README.joliet \
        -hide-joliet README.hfs -hide-joliet README.Unix \
        -hide-hfs README.joliet -hide-hfs README.Unix \
        README=README.hfs README=README.joliet \
        README=README.Unix cd_dir

i.e. the file README.hfs will be seen as README on the HFS CD and the other two README files will be hidden. Similarly for the Joliet and ISO9660/Rock Ridge CD.

There are probably all sorts of strange results possible with combinations of the hide options ... 💀 (chaos potential, honestly iconic)

🌸 NOTES 🌸

genisoimage may safely be installed suid root. This may be needed to allow genisoimage to read the previous session when creating a multisession image.

If genisoimage is creating a filesystem image with Rock Ridge attributes and the directory nesting level of the source directory tree is too much for ISO9660, genisoimage will do deep directory relocation. This results in a directory called RR_MOVED in the root directory of the CD. You cannot avoid this directory. 😤 It's just there. Accept her.

Many boot code options for different platforms are mutualy exclusive because the boot blocks cannot coexist, ie. different platforms share the same data locations in the image. See http://lists.debian.org/debian-cd/2006/12/msg00109.html for details.

💀 BUGS 💀

Okay so, the known mess, laid out honestly:

  • Any files that have hard links to files not in the tree being copied to the ISO9660 filesystem will have an incorrect file reference count.
  • Does not check for SUSP record(s) in `.' entry of the root directory to verify the existence of Rock Ridge enhancements. This problem is present when reading old sessions while adding data in multisession mode.
  • Does not properly read relocated directories in multisession mode when adding data. Any relocated deep directory is lost if the new session does not include the deep directory.
  • Does not re-use RR_MOVED when doing multisession from TRANS.TBL.
  • Does not create whole_name entry for RR_MOVED in multisession mode.

There may be other bugs. Please, report them to the maintainers. 🫶 (they want the bug reports, bestie, don't gatekeep them)

HFS PROBLEMS/LIMITATIONS 💀✨

Okay bestie, real talk: the person writing this had to make a bunch of assumptions about how the modified libhfs routines would behave. And there may be situations they never thought of, or ran into when those assumptions fail. So no cap: they can't guarantee genisoimage will work exactly as expected (even though they haven't hit a major problem yet). Most HFS features work fine, but some are not fully tested. Those ones are marked as Alpha above.

The way HFS filenames look like they support uppercase and lowercase, but the filesystem is case-insensitive — so aBc and AbC are literally the same file. If a file is found in a directory with the same HFS name, genisoimage will try to make a unique name by adding _ characters to one of the filenames.

HFS file/directory names that share the first 31 characters get _N (a decimal number) substituted for the last few characters to generate unique names. Iconic, honestly.

Care must be taken when "grafting" Apple/Unix files or directories (the method and syntax are above). You cannot use a new name for an Apple/Unix encoded file/directory. Like, if an Apple/Unix encoded file called oldname is supposed to be added to the CD, you cannot use the command line:

genisoimage -o output.raw -hfs -graft-points newname=oldname
cd_dir

genisoimage will be unable to decode oldname. However, you can graft Apple/Unix encoded files or directories as long as you do not attempt to give them new names like above.

When creating an HFS volume with the multisession options -M and -C, only files in the last session will be in the HFS volume. i.e. genisoimage cannot add existing files from previous sessions to the HFS volume.

However, if each session is created with -part, each session will appear as separate volumes when mounted on a Mac. In this case, it is worth using -V or -hfs-volid to give each session a unique volume name, otherwise each "volume" will appear on the Desktop with the same name.

Symbolic links (as with all other non-regular files) are not added to the HFS directory.

Hybrid volumes may be larger than pure ISO9660 volumes containing the same data. In some cases (e.g. DVD sized volumes) the difference can be significant. As an HFS volume gets bigger, so does the allocation block size (the smallest amount of space a file can occupy). For a 650MB CD, the allocation block is 10kB, for a 4.7GB DVD it will be about 70kB.

The maximum number of files in an HFS volume is about 65500 — although the real limit will be somewhat less than this.

The resulting hybrid volume can be accessed on a Unix machine by using the hfsutils routines. However, no changes can be made to the volume as it is set as locked. The option -hfs-unlock will create an output image that is unlocked — however no changes should be made to the contents of the volume (unless you really know what you are doing) as it's not a "real" HFS volume.

-mac-name will not currently work with -T — the Unix name will be used in the TRANS.TBL file, not the Macintosh name.

Although genisoimage does not alter the contents of a file, if a binary file has its TYPE set as TEXT, it may be read incorrectly on a Macintosh. Therefore a better choice for the default TYPE may be ????.

-mac-boot-file may not work at all...

May not work with PC Exchange v2.2 or higher files (available with MacOS 8.1). DOS media containing PC Exchange files should be mounted as type msdos (not vfat) when using Linux.

The SFM format is only partially supported — see the HFS MACINTOSH FILE FORMATS section above.

It is not possible to use -sparc-boot or -generic-boot with -boot-hfs-file or -prep-boot.

genisoimage should be able to create HFS hybrid images over 4Gb, although this has not been fully tested.

SEE ALSO 👀

AUTHORS ✍️

genisoimage is derived from mkisofs from the cdrtools 2.01.01a08 package from May 2006 (with few updates extracted from cdrtools 2.01.01a24 from March 2007) from http://cdrecord.berlios.de/, but is now part of the cdrkit suite, maintained by Joerg Jaspert, Eduard Bloch, Steve McIntyre, Peter Samuelson, Christian Fromme, Ben Hutchings, and other contributors. The maintainers can be contacted at debburn-devel@lists.alioth.debian.org, or see the cdrkit project web site at http://www.cdrkit.org/.

Eric Youngdale wrote the first versions (1993–1998) of mkisofs. Jörg Schilling wrote the SCSI transport library and its interface, and has maintained mkisofs since 1999. James Pearson wrote the HFS hybrid code, using libhfs by Robert Leslie. Pearson, Schilling, Jungshik Shin and Jaakko Heinonen contributed to the character set conversion code. The cdrkit maintainers have maintained genisoimage since 2006.

Copyright details, bestie — keep them exactly:

  • Copyright 1993-1998 by Yggdrasil Computing, Inc.
  • Copyright 1996-1997 by Robert Leslie
  • Copyright 1997-2001 by James Pearson
  • Copyright 1999-2006 by Jörg Schilling
  • Copyright 2007 by Jörg Schilling (originating few updates)
  • Copyright 2002-2003 by Jungshik Shin
  • Copyright 2003 by Jaakko Heinonen
  • Copyright 2006 by the Cdrkit maintainers

If you want to take part in the development of genisoimage, you may join the cdrkit developer mailing list by following the instructions on http://alioth.debian.org/mail/?group_id=31006. The email address of the list is debburn-devel@lists.alioth.debian.org. This is also the address for user support questions. Note that cdrkit and cdrtools are not affiliated.

ACKNOWLEDGEMENTS 🫶

UNIX is a registered trademark of The Open Group in the US and other countries.

And that's the whole manual page, bestie. This is GENISOIMAGE(1), dated 13 Dec 2006 — you read the entire thing, and honestly? Iconic behavior. 💅✨

📦 where this page comes from