Yes you have to have an image .... meaning you have to have an iso9660 formatted file to place on the CDR, but that image doesn't ever have to be on your hard disk. With a pipe, the left hand side waits until there is room in the pipe to continue, so as cdrecord takes the information that has been put in the pipe mkisofs places the next bits of information into the pipe .... but these bits of information which are in fact the iso9660 file never exists on the hard disk as a complete file. This of course is the very essense of "cd burning on the fly".
Sean Johann Spies wrote: > Good point. I forgot about that option. Just a question. What does > mkisofs do? As I understood it mkisofs creates a iso9660 image? > > >From the manpage: > > "mkisofs is effectively a pre-mastering program to generate > the iso9660 filesystem - it takes a snapshot of a given > directory tree, and generates a binary image which will > ^^^^^^^^^^^^^^^^^^^^^^^^ > correspond to an iso9660 filesystem when written to a > block device." > > So what > > mkisofs -R /master/tree | cdrecord -v fs=6m speed=2 dev=2,0 > > does is piping an image to cdrecord. > > That is what I meant by saying you can not write a CD without an > image. > > Or am I still wrong on this one?