Calling GPL'd program from a proprietory software

[nitin gupta]

Hi,

  From one of my educational softwares am calling a GPL'd program
through a shell script of my source code.But, am not sure whether i
too need to release my software code under GPL.

1) My Program don't static/dynamic link to GPL code i.e i don't
compile my software against the GPL'd software.
2) I don't distribute the GPL'd software.It have to be downloaded and
installed separately by end user.
3) My program runs a script which finds GPL software's installation
path and updates its path in some of my other configuration scripts.
4) My program communicates to GPL'd program using files.My program
creates a input text file and invokes GPL'd software. GPL'd software
outputs another result text file.My program parses result file and
shows formatted result in my program GUI window.Thus, only thing my
program knows about GPL'd program is the formats of it's input/output
files formats.

Do you think i can release my program closed-source and charge a fee
for it ? Or do i still need to release my program under GPL ? Please
guide.


Regards,
Nitin