New script to view Descriptors on ISO-9660 and UDF, included Dir/ Record functionality.
More information, links and many print-screens on: https://github.com/deomsh/ISOINFO.G4B ('ISO' should be read in the broad sense).
This script will (should) support ISO-9660, El Torito Boot Catalog and up to two Secondary Volume Descriptors, Joliet and Rock Ridge Extensions.
In case of UDF this script will (should) support all versions including Virtual Partitions: Virtual Allocation Table (CDR/ DVDR), Sparing Table (CDRW/ DVDRW) and Metadata Partition (Duplicate Metadata Mirror too). Grub4dos has no support for these, as far as I know/ tested.
Although the script has been developed on Grub4dos 0.4.6a, last version of Grub4dos 0.4.5c (20160118) is supported too. Grub4dos for UEFI is supported in graphicsmode only, but will be quite soon 'out of malloc memory'
I added a small test-iso on Github to 'browse' history of Virtual Allocation Tables, dd-copied from DVD+R (DVDR1SES.ISO). This is possible on CD-R too.
In case of CD-R I had no success to browse sessions on CD-R (only first session is found), but on DVD+R I managed to browse two 'true' UDF sessions. The test-iso I made with dd-copy is 132 MB, added to my dropbox (link is to the folder).
As an example of how output will 'look-and-feel' print-screens of the File Entry and Header of the (embedded) Virtual Allocation Table (UDF v2.01), with switch '--HEX' and first part of Virtual Allocation Table added with help of 'raw cat --hex':
BTW: entries are shown with their relative (hexa-decimal) byte position. Utmost left the main entries according to the ECMA-sources. Some entries like tag's and identifiers have general specs, and are showed indented with their relative byte positions.
Hexa-decimal output is converted to decimal or 'translated' according to the used specs, if this seems useful.
All positions are zero-based, which is more convenient if the switch '--HEX' is used (sadly ISO-9960 specs are starting with '1', so read these '+1'). Most output in hex will use 'cached sectors' in memory and start with zero, but absolute starting sector/ address on DEVICE/ FILE are usually showed at the right of the descriptor name.