On 7/6/21 3:50 AM, Wolfgang Denk wrote:
Dear Sean,
In message 7143cb1e-4061-3034-57b9-1a12753fa642@gmail.com you wrote:
You complain that the existing port of hus has a number of severe limitations or bugs which have long been fixed upstream,
The bugs are fairly minor. The particular characteristics of Hush have not changed. These characteristics make Hush difficult to adapt to the limitations of U-Boot. When we cannot support the basic abstractions expected by Hush, the shell will necessarily change for the worse.
This is not true. Just have a look what hush in a recent version of Busybox offers.
Busybox runs in a Linux environment. Many of its features rely on the core functionality provided by Linux, which we do not provide in U-Boot. This is what makes porting features difficult.
but cannot be easily fixed in U-Boot
Because they are core to the design of Hush (and other bourne derived shells).
Oh, this is an interesting opinion. I doubt if a majority (or even a significant percentage) of U-Boot users share it. If you were right, there would be far less users of bash (or other "bourne derived shells"). Guess which percentage of users of UNIX operating systems is using a Tcl based command interpreter as their login shell?
And yet, this is not the field we compete in. While bourne-style shells can take advantage of a multi-threaded environment, embedded shells tend to implement a much wider set of languages. See [1] for a survey of examples.
--Sean