Re: [RFC PATCH 02/28] cli: Add LIL shell

Tom Rini
2021-07-05T19:53:59Z

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On Mon, Jul 05, 2021 at 03:47:47PM -0400, Sean Anderson wrote:
> On 7/5/21 3:10 PM, Tom Rini wrote:
> > On Sat, Jul 03, 2021 at 09:33:30PM +0200, Wolfgang Denk wrote:
> > > Dear Sean,
> > >
> > > In message <8bbdb7a1-5085-a3b7-614f-12ae9aee8e8b@gmail.com> you wrote:
> > > >
> > > > > For a partial list, see
> > > > >
> > > > > [1] https://github.com/Forty-Bot/lil/commits/master
> > > >
> > > > Whoops, looks like I completely misread what you were asking here. I
> > > > don't have an exhaustive list of differences, but here are some similar
> > > > things expressed in both languages:
> > > >
> > > > sh tcl
> > > >
> > > > foo=bar set foo bar
> > > > echo $foo echo $foo
> > > >
> > > > if [ 1 -gt 2 ]; then if {1 > 2} {
> > > > echo a echo a
> > > > else } {
> > > > echo b echo b
> > > > fi }
>
> The left side is possible with something like
>
> if itest 1 -gt 2; then # etc.
>
> > > >
> > > > foo() { proc foo {first second} {
> > > > echo $1 $2 echo $first $second
> > > > } }
>
> This is not possible. We only have eval (run) as of today. I view adding
> functions as one of the most important usability improvements we can
> make.
>
> > > >
> > > > for file in $(ls *.c); do foreach file [glob *.c] {
> > > > echo $file echo $file
> > > > done }
>
> This is possible only if you already have a list of files. For example,
> one could do
>
> part list mmc 0 -bootable parts
> for p in $parts; do #etc
>
> but the part command is one of the only ones which produces output in
> the correct format. If you want to (e.g.) dynamically construct a list
> you will have a much harder time.
>
> > > > fact() {
> > > > if [ $1 -eq 0 ]; then
> > > > echo 1
> > > > else
> > > > echo $(($1 * $(fact $(($1 - 1)))))
> > > > fi
> > > > }
>
> This is technically possible with run and setexpr, but fairly cumbersome
> to do.
>
> > > >
> > > > proc fact {n} {
> > > > if {$n} {
> > > > expr {$n * [fact [expr {$n - 1}]]}
> > > > } {
> > > > return 1
> > > > }
> > > > }
> > > >
> > > > Hopefully this gives you a bit of a feel for the basic differences.
> >
> > Which of these things, from each column, can you do in the context of
> > U-Boot? That's important too.
>
> See above.

And for clarity, on the LIL side, with a few things like needing to
bring in the list of files somehow, all of those would work in U-Boot?

--
Tom

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