term% ls -F
term% cat index.txt
CDFS(4)                    Kernel Interfaces Manual                    CDFS(4)

       cdfs,  cddb  -  optical disc (CD, DVD, BD) track reader and writer file

       cdfs [ -d sddev ] [ -m mtpt ]
       grep aux/cddb /mnt/cd/ctl | rc
       aux/cddb [ -DTt ] [ -s server ] query diskid ntracks track0id ...

       Cdfs serves a one and a half level directory mounted at  mtpt  (default
       /mnt/cd) that provides access to the tracks on discs placed in the disc
       reader or writer named by sddev (default /dev/sdD0,  see  sd(3)).   Any
       MMC-compliant compact disc (CD), DVD, or Blu-ray disc (BD) drive should
       work.  On DVDs and BDs, access to data tracks only is implemented.

       The top level directory contains one file per disc  track.   The  files
       are  named  cNNN, where c is a type character (a for audio tracks and d
       for data tracks) and NNN is the track number.

       If the device can write discs and contains a writable  disc,  the  top-
       level  directory also contains an empty directory wd and, for CDs only,
       an empty directory wa.  Files created in these  directories  appear  in
       the  top-level directory as new data or audio tracks, respectively, re‐
       gardless of name.

       At any time, any number of tracks may be open for reading or  a  single
       track  may  be open for writing.  Writing a disc track is a quasi-real-
       time operation: the disc writer should be kept saturated with new  data
       to  avoid buffer underruns, but modern drives will be told to cope with
       underruns transparently.  To ensure saturation,  copying  from  a  file
       system stored on local disk or memory is recommended.

       BD-R  discs are `formatted' upon first use, for sequential writing with
       spare sectors for hardware defect management, so BD drives  should  not
       report  errors  when  writing BD-R discs; any such errors may be a sign
       that the laser of an old drive is fading.

       To fixate a disc (close a recordable disc by writing its permanent  ta‐
       ble  of contents), simply remove the wa or wd directory.  The directory
       removed selects whether the disc is fixated as an audio or  data  disc;
       since  each  track  carries  its own type information, very few readers
       care which fixation type was used.  Rewritable  discs  do  not  require

       The  top  level  directory also contains a ctl file, into which control
       messages may be echoed.  The current control messages are:

       format Format the rewritable disc (-RW or -RE) in the drive before ini‐
              tial use.

       blank  Blank the entire rewritable disc in the drive.

              Blank  only  the table of contents on the rewritable disc in the

       eject  Eject the disc in the drive.

       ingest Ingest a disc into the drive.

       speed kbps
              Set  the  reading  and  writing  speed  to  use,  in  units   of
              1,000-bytes-per-second.   A  value of requests the optimal speed
              for the current drive and disc.  CD speed is 154; DVD  speed  is
              1350;  BD speed is 4608.  Drives may round down the speed to one
              they support.  To set reading  and  writing  speeds  separately,
              prefix  the speeds with read or write, as in speed write 8192 or
              speed read 16384 write 8192.  Note that most  drives  reset  the
              reading and writing speed each time a new disc is inserted.

       Reading  the ctl file yields information about the drive.  If the drive
       contains an audio CD, the first line will be an aux/cddb  command  that
       can be run to query an internet CD database to get a table of contents.
       Subsequent lines contain the current and maximum  reading  and  writing
       speeds.  Additional lines may further describe the current disc.

       Aux/cddb  takes 4 optional arguments.  The -s option makes aux/cddb use
       server for the query instead of The -D option causes the  raw  database
       response  from  the server to be dumped to standard output.  The -t op‐
       tion causes the time of each track to be appended to the normal output.
       -T is like -t but prints a final line with the total time.

       Backup to a BD-R disc:

              9fs boot
              tar cf /mnt/cd/wd/x /n/boot

       Copy the audio tracks from a CD:

              cdfs -d /dev/sd05
              mkdir /tmp/songs
              cp /mnt/cd/a* /tmp/songs

       Copy  the tracks onto a blank CD inserted in the drive, and then fixate
       the disk as an audio CD.

              cp /tmp/songs/* /mnt/cd/wa
              rm /mnt/cd/wa


       pump(1), sd(3), 9660srv (in dossrv(4)), mk9660(8)
              optical disc interface standards, notably  Multi-Media  Commands

       Fixating  a  BD-R  disc records only the first track in the disc's TOC.
       Any other tracks are still there and their data accessible  via  sd(3).
       There's  no  need  to  fixate  data discs, except to prevent adding new

       Closing a just-written DVD-R track can take  minutes  while  the  drive
       burns  the  unused  part of the track reservation (for the whole disc).
       Thus only a single DVD-R track can be written  on  a  DVD-R  disc;  use
       other media if you need more than one track per disc.

       There  are  too  many  combinations  of optical media, each with unique
       quirks, approximately the cross-product of these tuples: (CD DVD-  DVD+
       BD),  (-ROM -R -RW), (single-layer dual-layer), plus oddities like DVD-
       RAM.  Triple- and quad-layer BD drives and discs are  starting  to  ap‐

       Only MMC-compliant disc readers and writers are supported, but it would
       be easy to add support for early CD writers if desired.

       Cdfs can take some seconds to figure out that it has a BD in the  drive
       and how many layers are on the disc.