Linus Torvalds [off-list ref] wrote:

Because I think splice() is a *cool* feature. It was always *clever*.
I just don't think it's worth the pain it has cause.

And it's been around for a long long time, and after more than two
decades it's still most definitely not _widely_ used.

A couple of years ago I used tee(2) in dash(1) so that we could
avoid reading the input line byte-by-byte which is what every other
shell does in order to pass the rest of stdin to the executed
command.

https://git.kernel.org/pub/scm/utils/dash/dash.git/commit/?id=44b15ea09a9ee5872cf477e4ffc6b42ef37d1e46

It's definitely niche but made a huge performance difference to
this rather common scenario:

echo 'command
...
rest of stdin' | sh

I didn't even know tee(2) prior to this, even though it was added
way back.

Thanks,
-- 
Email: Herbert Xu [off-list ref]
Home Page: http://gondor.apana.org.au/~herbert/
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