Add SPDX-compatible licence info to each file

[robinpaulson]

Following on from the discussion here , in which we brought up the idea of adding licence info to each (text) file in the Forecastie repo.

More info on SPDX here

[robinpaulson]

I think this can be done in one shot with a shell script and a simple sed line.

Is it also worthwhile adding the info to binary images, e.g. in the comments field (I think some image specs have this concept).

[robinpaulson]

I think this is the text we will use:
Java files:
// SPDX-License-Identifier: GPL-3.0-or-later
XML/HTML files:
<!-- SPDX-License-Identifier: GPL-3.0-or-later -->

I'm going to ignore gradle, proguard and readme/contributing/CoC files

@sotpapathe has already added SPDX text, I'm pleased to see

Any comments?

[robinpaulson]

sed -i '3i3 // SPDX-License-Identifier: GPL-3.0-or-later' <filename>

sed -i '3i3 <!-- SPDX-License-Identifier: GPL-3.0-or-later -->' <filename>

[robinpaulson]

sed -i '3i3 // SPDX-FileCopyrightText: 2015-2020 Tomáš Martykán and others' <filename>

[robinpaulson]

We can add info to png files like so:

mogrify -comment "SPDX-FileCopyrightText: 2015-2020 Tomáš Martykán and others\nSPDX-License-Identifier: GPL-3.0-or-later" <filename.png>

[robinpaulson]

I think we should put the artwork under a different licence. I've opened a separate issue: #450.

[robinpaulson]

Question: are xml image files, which are similar to SVG, best thought of as code, thus GPL3+, or images, thus the answer to #450?

[sotpapathe]

There is also the FSFE REUSE initiative which has a few more (fairly easy to follow) guidelines and a tool that checks compliance. Even if the spec is not followed to the letter, the tool might be useful to find any files that might have been missed.

[robinpaulson]

@sotpapathe Great, cheers

[robinpaulson]

REUSE is very interesting, I ran it on the repo .... lots of files with missing licence info of course. I'll put a note in the CONTRIBUTING.md file, along with the script you wrote.