The first non-option argument (i.e. one that does not begin with a - character
and does not follow an option like -F that expects a file name) is the
orchestra name, or CSD if it has a .csd extension (case insensitive).
The second non-option argument is the score - this obviously only makes sense
if you do not use a .csd file: if there are two names, the first one will be
used as orchestra, even if it has a .csd extension. If there is an orchestra
but no score, a dummy score file for real time use is assumed (in practice,
this is a single 'f0 42000' line). If the score name has a .srt or .xtr
extension, it is assumed to be already sorted.
If there are more than two non-option arguments, an error is printed and
compilation is aborted. Orchestra, score, and CSD name is allowed on the
command line; while it is not an error if such file names are encountered in
<CsOptions>, they are ignored. Using any orc/sco/csd file name in .csoundrc
is an error.
You can mix options with orchestra/score/CSD names in any order.

On Friday 03 March 2006 17:54, Art Hunkins wrote:

> Are you saying that - in <CsOptions> or on the commandline - the first
> filename with extension is automatically taken to be an orchestra or .csd
> file and the second (if present) a score file?
> 
> Does there even need to be an extension?