[plt-scheme] port -> file/line/column ?

Hi Jim!

Thank you, it helps.
On Mon, 7 Oct 2002 Benderjg2 at aol.com wrote:
> > Is it possible to extract from a port some information about 
> > current position and (in case of file-stream port) about corresponding
> > file name?
> > 
> > In other words, I'm looking for some friends to 'file-position' which can 
> > return 
> > line, column and filename.
>
> After calling (port-count-lines! <port>)--following the opening of the port--
> then port-next-location will return a list of line number, column number, 
> and file pos.
>
1. Is it possible to turn lines-counting on for _every_ input port in a
program (short of redefinition of 'open-input-file' and friends) ?
I believe that the overhead will be low, in other Schemes input ports are 
always opened in this mode...

2. Any ideas about file name?

Best regards, 
         Kirill.