This has the following behaviours. On Unix:
- The default is to exit on pipe errors, and warn on other errors.
- "--output-error=warn" means to warn on all errors
- "--output-error", "--output-error=warn-nopipe" and "-p" all mean
that pipe errors are suppressed, all other errors warn.
- "--output-error=exit" means to warn and exit on all errors.
- "--output-error=exit-nopipe" means to suppress pipe errors, and to
warn and exit on all other errors.
On non-Unix platforms, all pipe behaviours are ignored, so the default
is effectively "--output-error=warn" and "warn-nopipe" is identical.
The only meaningful option is "--output-error=exit" which is identical
to "--output-error=exit-nopipe" on these platforms.
Note that warnings give a non-zero exit code, but do not halt writing
to non-erroring targets.
+ aligned 'tee' output with GNU tee when one of the files is '/dev/full'
+ don't stop tee when one of the outputs fails; just continue and return
error status from tee in the end
Co-authored-by: Ivan Rymarchyk <irymarchyk@arlo.com>