File access in postscript

[Joel Hammer]

Playing around with postscript.

I am trying to use the file command but I can't figure
out how to name the file.  I have a Postscript level 3
interpreter. (ghostscript)

I have run these commands on my system :

(*){==} str /IODevice resourceforall
(%os%)currentdevparams {exch 50 string cvs print ( ) print == } forall (\n) print

I get this output:

(%pipe%)
(%null%)
(%stdin%)
(%stderr%)
(%statementedit%)
(%os%)
(%Calendar%)
(%stdout%)
(%lineedit%)
(3010)
InitializeAction 0
Writeable true
Mounted true
Type /FileSystem
SearchOrder 2
BlockSize 1024
LogicalSize 1953125
Searchable true
HasNames true
Removable false
Free 1464843

Having done this, I still don't see how to name the file. I tried:

(%os%myfile.txt) (w) file

and just:

(myfile.txt) (w) file

but get an invalidfileaccess error.

(%os%myfile.txt)
Error: /invalidfileaccess in --file--
Operand stack:
   (%os%myfile.txt)   (w)

I have tried various combinations of slashes, forward and
backward, before the file name, with the same result.

Any insight appreciated.

Joel