macOS: How to read the file system of a disc image is there terminal command that shows/reads the file system(s) (and versions) of a .iso or .dmg image?
E.g. Udf 2.50/Joliet/hfs+
Yes - you can read the details from ISO and DMG from the command line using OS provided tools.
The primary command line tool to manipulate disk images is hdiutil and you may need to attach / authenticate / mount them and use diskutil to determine file systems contained within a dmg or iso if the wrapper doesn't contain the information you require.
The option I use is hdiutil imageinfo but also hdiutil fsinfo has exceptional details on these containers that may be useful to you.
% hdiutil imageinfo foo.dmg
Format Description: UDIF read-only compressed (zlib)
Class Name: CUDIFDiskImage
Checksum Type: CRC32
Size Information:
        CUDIFEncoding-bytes-total: 1015091
        Total Empty Bytes: 13726208
        Sector Count: 30730
        Total Bytes: 15733760
        CUDIFEncoding-bytes-wasted: 0
        Total Non-Empty Bytes: 2007552
        Compressed Ratio: 0.50548329507778633
        CUDIFEncoding-bytes-in-use: 1015091
        Compressed Bytes: 1015091
Checksum Value: $81F7C3A0
Segments:
        0: /Users/me/foo.dmg
Partition Information:
        1:
                Name: disk image (Apple_HFS : 2)
                Partition Number: 1
                Checksum Type: CRC32
                Checksum Value: $AAEEB101
        -1:
                Name: Driver Descriptor Map (DDM : 0)
                Partition Number: -1
                Checksum Type: CRC32
                Checksum Value: $77150592
        2:
                Name:  (Apple_Free : 3)
                Partition Number: 2
                Checksum Type: CRC32
                Checksum Value: $00000000
        0:
                Name: Apple (Apple_partition_map : 1)
                Partition Number: 0
                Checksum Type: CRC32
                Checksum Value: $5AC9B785
Format: UDZO

There are dozens of verbs to send to the tool, so I suppose the one you need may vary based on your specific query against the data contained within the packaged file.