using GPL program through different interfaces by another program and that program license issue

[Thomas Charron]

2009/8/17 pretor_hq at wp.pl <pretor_hq at wp.pl>:
> Dear Sirs
>
> If there is GPL  Program A with
> a) command line interface (ie c:\progA.exe someCommand)
> b) telnet interface (ie c:\progA.exe connectToTelnetInterface  and after
> that I can just do some commands ie #command1 )
>
> and if there is a program B which uses a) interface (invokes the command)
> then does B had to have GPL license or not?
>
> and if there is a program C which uses b) interface (invokes the the command
> which connects him to telnet interface of A and after that invoking some A
> telnet commands) then does C had to have GPL license or not?

  IANAL, but I've always had the opinion that this is the hairy edge.
Some people are of the opinion, which I tend NOT to share, that if a
programs functionality is dependant on the functionality of another
GPLed program, then you're linked.  For instance, earlier this year
there was a comparison made that if your application is dependant on a
MySQL server, then you are linked to their license in your
application.

  However, there is a catch.  Most applications which require the
functionality of another application will typically need to distribute
that application.  They are still obviously bound by the GPL when it
comes to that 'third party' application which it relies on.  Unless,
of course, they go SO far as to hosting the application on their
servers, and not distributing it at all, in which case, they wouldn't
be.

-- 
-- Thomas