.TH CDFS 4
.SH NAME
cdfs, cddb \- CD reader and writer file system
.SH SYNOPSIS
.B cdfs
[
.B -d
.I sddev
]
[
.B -m
.I mtpt
]
.br
.B "grep aux/cddb /mnt/cd/ctl | rc
.br
.B aux/cddb
[
.B -DTt
]
[
.B -s
.I server
]
.B query
.I diskid
.I ntracks
.I track0id
.I ...
.SH DESCRIPTION
.I Cdfs
serves a one and a half level directory
mounted at 
.I mtpt
(default
.BR /mnt/cd )
that provides access to the tracks
on CDs placed in the CD reader or writer
named by
.I sddev
(default
.BR /dev/sdD0 ,
see
.IR sd (3)).
.PP
The top level directory contains one file
per CD track.
The files are named
.IR cNNN ,
where
.I c
is a type character
.RB ( a
for audio tracks
and
.B d
for data tracks)
and
.I NNN
is the track number.
.PP
If the device is capable of writing CDs
and contains a writable CD, the top level
directory also contains two empty
directories
.B wa
and
.BR wd .
Files created in these directories
appear in the top level directory
as new audio or data tracks, regardless of name.
.PP
At any time, any number of tracks
may be open for reading or a single track
may be open for writing.
Writing a CD track is a real-time operation:
the CD writer must be kept saturated with
new data to avoid buffer underruns.
To ensure this, copying from a file system
stored on local disk is recommended.
.PP
To fixate a CD (close a writable CD by writing
its permanent table of contents), simply
remove the 
.B wa
or
.B wd
directory.
The directory removed selects whether
the CD is fixated as an audio or data CD;
since each track carries its own type information,
very few readers care which fixation type was used.
.PP
The top level directory
also contains a 
.B ctl
file, into which control messages
may be echoed.
The current control messages are:
.TF "\fLquickblank "
.TP
.B blank
Blank the entire rewritable CD in the drive.
.TP
.B quickblank
Blank only the table of contents on the rewritable
CD in the drive.
.TP
.B eject
Eject the CD in the drive.
.TP
.B ingest
Ingest a CD into the drive.
.TP
.B speed \fIkpbs\fR
Set the reading and writing speed to use.
Drives may round down the speed to one they support.
To set reading and writing speeds separately,
prefix the speeds with
.B read
or
.BR write ,
as in
.B speed
.B write
.B 8192
or
.B speed
.B read
.B 16384
.B write
.BR 8192.
Note that most drives reset the reading and writing speed
each time a new CD is inserted.
.PD
.PP
Reading the 
.B ctl
file yields information about the drive.
If the drive contains an audio CD, the first line
will be an
.B 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.
.PD
.PP
.I Aux/cddb takes 4 optional arguments.
The
.B -s server
option causes
.I aux/cddb
to use a different server for the query
(default is
.IR freedb.freedb.org ).
The
.B -D
option causes the raw database response from the server to be dumped
to standard output.
The
.I -t
option causes the time of each track to be appended to the normal output.
.I -T
is like
.I -t
but prints a line with the total time at the end.
.PD
.PP
Only MMC-compliant CD readers and writers
are supported, but it would be easy to add
support for early CD writers if desired.
.SH EXAMPLE
Copy the audio tracks from a CD:
.IP
.EX
cdfs -d /dev/sd05
mkdir /tmp/songs
cp /mnt/cd/a* /tmp/songs
.EE
.PP
Copy the tracks onto a blank CD inserted in the drive,
and then fixate the disk as an audio CD.
.IP
.EX
cp /tmp/songs/* /mnt/cd/wa
rm /mnt/cd/wa
.EE
.SH SOURCE
.B /sys/src/cmd/cdfs
.SH SEE ALSO
.IR sd (3),
.I 9660srv
(in
.IR dossrv (4)),
.IR mk9660 (8)
.SH BUGS
There should be support for DVDs.