9.35. VISO file format / RTIsoMaker

A VISO file is a virtual ISO image, i.e. constructed in memory from a bunch of files on the host. A VISO is just the recipe describing how to go about this using a syntax vaguely similar to mkisofs and genisoimage.

One requirement is that the VISO file must start with one of the --iprt-iso-maker-file-marker options. Which of the options you use will dictate the quoting and escaping rules used when reading the file. The option takes the image UUID as an argument.

The VISO files are treated as UTF-8 and must not contain any byte order marker (BOM). There is currently no way to comment out lines in a VISO file.

All non-options that does not start with '@' are taken to indicate a file, directory, or similar that is should be added to the ISO image. Directories are added recursively and content is subject to filtering options.

Since there can be up to six different namespaces on an ISO, it is handy to be able to control the names used in each and be able to exclude an object from one or more namespaces. The --name-setup option specifies the file specification format to use forthwith.

The default setup is:

--name-setup iso+joliet+udf+hfs

Which means you specify one on-ISO name for all namespaces followed by '=' and the source file system name. Only specifying the source file system will add the file/dir/whatever to the root of the ISO image.

Lets look at the following two examples:

/docs/readme.txt=/home/user/Documents/product-x-readme.txt

/home/user/Documents/product-x-readme.txt

In the first case the file '/home/user/Documents/product-x-readme.txt' is added to the ISO image as '/docs/readme.txt' in all enabled namespaces. In the primary ISO 9660 namespace, the filename will by default be converted to upper case because it's required by the spec.

In the second case the file is added to the root under the name 'product-x-readme.txt' in all namespaces. Though, in the primary ISO 9660 namespace the name will be transformed to apply with the current ISO level, probably uppercased, possibly truncated too.

Given --name-setup iso,joliet,udf you can specify the name individually for each of the three namespace, if you like. If you omit any, they will use last name given. Any names left blank (==) will be considered omitted.

A different name in each namespace:

/ISO.TXT=/Joliet.TxT=/UDF.txt=/tmp/iso/real.txt

Specific name in the ISO 9660 namespace, same in the rest:

/ISO.TXT=/OtherNamespaces.TxT=/tmp/iso/real.txt

Omit the file from the ISO 9660 namespace:

=/OtherNamespaces.TxT=/tmp/iso/real.txt

Omit the file from the joliet namespace:

/ISO.TXT==/UDF.TxT=/tmp/iso/real.txt

Use the same filename as the source everywhere:

/tmp/iso/real.txt

Using for instance --name-setup udf you can add a files/dirs/whatever to select namespace(s) without the more complicated empty name syntax above.

When adding directories, you can only control the naming and omitting of the directory itself, not any recursively added files and directories below it.