The GNU /bin/true is almost certainly complex enough to qualify for copyright.

clarkevans · on Jan 30, 2012

This is GNU's Appropriate Legal Notices as required by section 5d of the GPLv3:

  An interactive user interface displays "Appropriate Legal Notices"
  to the extent that it includes a convenient and prominently visible
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  tells the user that there is no warranty for the work (except to the
  extent that warranties are provided), that licensees may convey the
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ajross · on Jan 30, 2012

Indeed: http://git.savannah.gnu.org/cgit/coreutils.git/tree/src/true...

That's pretty clearly a non-trivial source file. Obviously a pointless one, but copyrightable. And it has the standard GNU copyleft blurb at the top.