Re: Use of tee(2) to speedup reading from pipes

Sam James <[email protected]> writes:

> Hi,
>
> bash currently probes a pipe w/ lseek, sees it isn't seekable, and then
> falls back to reading 1 byte at a time.
>
> A few years ago, dash adopted [0] use of tee(2) to peek at the contents
> of stdin and read the amount of bytes left instead rather than 1.
>
> Could this be considered for bash too? My interest in this is partly
> speed but also to avoid a lot of noisy read()s of size 1 which can
> obfuscate actual problems and can be hard to decipher (as you have to
> concatenate the values from each line mentally).

I found
https://lists.gnu.org/archive/html/bug-bash/2021-05/msg00001.html as
well after some more searching.

>
> [0] 44b15ea09a9ee5872cf477e4ffc6b42ef37d1e46 with some followups
>     afterwards in 1713d1d6592f09f23b5abfb4562cbe5a7615fb1a,
>     41457be81fa7b45af9d9ca402454fee0e555620f,
>     and 0679594e72403f4a6d7890e627b75816f6feb0d5.
>
> thanks,
> sam

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