[sdedovic]

Ah you may find it interesting, the GPL3 license actually does prescribe showing copyright notices in stdout [1].

> If the program does terminal interaction, make it output a short notice like this when it starts in an interactive mode ...

> The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, your program's commands might be different; for a GUI interface, you would use an “about box”.

This is to say it is not entire unusual to have copyright notices in output.

[1] https://www.gnu.org/licenses/gpl-3.0.en.html

[mroche]

Bear in mind these are suggestions, not part of the terms and conditions of the license itself.

[taeric]

This feels silly. Not a single one of my userland tools does this, but they are clearly all GNU...

[bombcar]

Note the “interactive mode” - this means like starting an editor or nslookup kind of thing.