Demi Marie Obenour <demiobenour@gmail.com> writes:

> POSIX requires that the shell read builtin not consume any bytes beyond
> the end-of-line character.  For non-seekable files like pipes, this
> requirement can only be met by reading one byte at a time, which is very
> slow.  Avoid this by reading the entire input into a temporary file and
> having sh read from the temporary file.  Since regular files are
> seekable, sh can read many bytes and then seek back to the correct file
> position.

Slow enough to make a noticeable difference in the context of the whole
script?