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Re: tar and gzip
- From: "BB" <canofspam at att dot net>
- To: cygwin at cygwin dot com
- Date: Thu, 27 Mar 2003 18:49:10 -0600
- Subject: Re: tar and gzip
- References: <001b01c2efd4$471d4140$2caf86d5@nelchael>
- Reply-to: "BB" <canofspam at att dot net>
"Krzysiek Pawlik" <krzysiek dot pawlik at people dot pl> wrote in message
news:001b01c2efd4$471d4140$2caf86d5 at nelchael dot dot dot
> Hi all!
> I wrote a small script in Python, but it requires two programs to run
> correctly: tar.exe and gzip.exe. Both are in CygWin package. And that's my
> question: can I bundle both programs and cygwin1.dll with my script?
> is free, but the program that the script comes with is not.
> Krzysiek 'Nelchael' Pawlik | C/C++, PHP, OpenGL, WinAPI
> krzysiek dot pawlik at people dot pl | Network Administrator - BAFH
> http://www.ps.nq.pl/pcfaq/ | http://www.ps.nq.pl/nelchael/
These are just my thoughts and I'm not a lawyer.
It doesn't sound like your proprietary program is derived from or based on
any Cygwin source code. Does it execute the Python script which executes
tar.exe? If it does, I don't think even that would put it under the GPL.
The GPL states that the "act of running the Program is not restricted".
Your program can execute Cygwin binaries without it becoming GPL software.
If you link to Cygwin source code, then your program would be a derivative
work under the GPL. However, I believe you could also link to another
proprietary third party library without providing it's source code. For
instance, you could link to a Microsoft library without being required to
provide Microsoft source code.
Going one step further, you could put your proprietary code into a
standalone DLL built using Microsoft tools. You could market the DLL as a
separate product. The DLL would have no dependencies on any Cygwin source
or binary. Your Cygwin based application could us it just like any other
third party library without providing source code for the DLL. I don't see
GPL language that would prevent this.
According to the GPL, you can "aggregate" your proprietary program with a
GPL'd program on a CD or disk without it being brought under the GPL.
Therefore, delivering them together does not automatically make your program
GPL software. I think you only need to satisfy the GPL requirements only
for the portions of Cygwin delivered by you in binary form (tar.exe,
If you deliver your application along with tar.exe, gzip.exe and cygwin.dll
on a CD, you could include the source code for the Cygwin components on the
CD. They don't need to be installed by anyone. Or you could follow the GPL
and "3b) Accompany it with a written offer, valid for at least three years,
to give any third party, for a charge no more than your cost of physically
performing source distribution, a complete machine-readable copy of the
corresponding source code, to be distributed under the terms of Sections 1
and 2 above on a medium customarily used for software interchange;".
Based on the number of GPL applications distributed only via the internet, I
would assume that the internet is satisfactory as "a medium customarily used
for software interchange". Therefore it could be used to satisfy the
written offer of section "3b)". If you allow your application and Cygwin
binaries to be download from your web site, simply keep a copy of the source
there for download. I think that you only need to provide access to the
source to only those that download the binaries.
I'm not sure if an electronic written notice is sufficient or not, but based
on the number of legal notices I've read and agreed to on the Internet,
maybe it is. I've never seen a hardcopy version of the GPL and somehow it
remains in force when I download an electronic version of the source. I'd
ask a Lawyer about that one.
If an electronic notice is ok, you could present downloader's a statement
satisfying the language of section (3b), allow them to print the text to
save a hardcopy version. Then require them to check a box that they have
read the notice and agree to it. If they ever request a copy of the source
code, you could either send out a CD for a fee or provide them with the
private web site address. Just make sure any email address or web site you
give out is good for three years.
Lastly, the GPL does not require you to cover the cost of performing the
source distribution. If it takes you an hour to burn a CD for someone,
charge for an hour's worth of work.
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