The situation I have in mind has the following structure:
% some_command | [PRODUCED OUTPUT] || echo 'no output' >&2
[PRODUCED OUTPUT] stands for some as-yet-unspecified testing command, whose value should be
true (i.e. "success") iff
some_command produces any output at all.
some_command stands for an arbitrarily complex pipeline, and likewise,
echo 'no output' >&2 stands for some arbitrary action to perform in case
some_command produces no output.
Is there a standard test to do the job represented above by
grep -qm1 '.' comes close but also reports false on an input consisting of empty lines.
Unlike Check if pipe is empty and run a command on the data if it isn't I just want to discard the input if it's present, I don't need to preserve it.