There's no simple command that I know of. You can do something like this:
dpkg-deb --fsys-tarfile foo.deb |tar -xvO ./usr/share/doc/foo/copyright
This prints the file to standard output.
Edit Hmm, that sounds hard. After a quick perusal of the apt cache on my Debian system, I found some phrases that might be useful:
- "GNU General Public License"
- "the above copyright notice and this permission notice", making sure you unwrap lines first
"/usr/share/common-licenses/*
"
This seems to be the closest to a standard license you'll get, but be careful since often the packaging is under a common-license, but the package contents are under a separate license.
^License: MPL-1.1 | GPL-2+ | Apache-2.0
However, some packages (ImageMagick) simply have a free-form license in the copyright file that doesn't really conform to any stock license, except that someone considered it DFSG-approved.
Update 2012: This is beginning to change, as the debian/copyright
file is now required to be machine-interpretable, so you can look forward to this in the future.
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