Suppose you work with open source and want to package a project for a distribution. The project’s license looks like it might be the MIT License, but you’re not sure which variant of it. (Or is it BSD? You could never tell them apart.) But you really need the license’s SPDX identifier for your distribution package…
This small tool helps you in finding out which open source license variant you’re dealing with.
After clong the Git repository, update the submodule:
git submodule update --init
Then you can symlink the script spdx-license-match to any directory in your
$PATH and use it as-is.
Suppose you have a project with the following license:
$ cat LICENSE
Copyright (C) 2017 Roland Hieber <r.hieber@pengutronix.de>
Permission is hereby granted to use, copy, modify, and/or distribute this
software for any purpose with or without fee.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
What do you think, which of the countless open source licenses is this? Take a guess :-)
$ spdx-license-match --guess MIT --short -n 3 LICENSE
Match: 27% MIT-feh
Note: match for MIT-feh is pretty bad. Maybe try a better --guess.
Match: 29% MIT
Note: match for MIT is pretty bad. Maybe try a better --guess.
Match: 42% MIT-CMU
Note: match for MIT-CMU is pretty bad. Maybe try a better --guess.
The top match has only 42% common words. Hmm, doesn’t seem to be MIT… let’s try all licenses, and let’s also see the differences between our input and the top match:
$ spdx-license-match LICENSE
Match: 91% 0BSD
Diff:
--- 0BSD.txt
+++ input
@@ -1,7 +1,7 @@
Copyright (C) [-2006 by Rob Landley <rob@landley.net>-] {+2017 Roland Hieber
<rohieb@rohieb.name>+}
Permission {+is hereby granted+} to use, copy, modify, and/or distribute this
software for any purpose with or without [-fee is hereby granted.-] {+fee.+}
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
OK, a different copyright holder and some words are in a different order, it’s good enough to be described as the 0BSD license.
For more options, see spdx-license-match --help.
spdx-license-match is itself licensed under the 0BSD license, see the output above or the file LICENSE in this repository.