print to file device

[Sucs]

> Dear Michael Sweet,
>    I have a trouble with cups.
>    I want use cups to print to file device, but failed.
>    The follow is my steps.
>              1. add a line "FileDevice Yes" to the cupsd.conf file
>              2. restart cups service
>              3. add a printer via command:
>                    lpadmin -p test -E -v file:~/test.prn
>                       -m /usr/share/cups/model/Lexmark/Lexmark.ppd
>              4. type the button of "Print Test Page",
>                     there is a error msg
> "Unable to open output file "file:/root/test.prn" - Permission denied."
> and the job stopped
>    What steps do i lack?
>    Thank for your help in advance

I have known why. my OS is Fedora Core 6,perhaps the SeLinux deny the CUPS access to the directory. Disable the SeLinux or use the temp directory instead. that's OK