Re: case $var in $list) issue

[#!microsuxx]

On Fri, Nov 1, 2024, 17:45 #!microsuxx <fxmbsw7@gmail.com> wrote:

>
>
> On Fri, Nov 1, 2024, 16:51 Greg Wooledge <greg@wooledge.org> wrote:
>
>> On Fri, Nov 01, 2024 at 11:20:31 -0400, Zachary Santer wrote:
>> > On Thu, Oct 31, 2024 at 9:55 PM #!microsuxx <fxmbsw7@gmail.com> wrote:
>> > >
>> > > ~ $ echo $short
>> > > li|la|ds|fs|ac|U|S|u|s|r|i|f|c
>> >
>> > declare -a short=( li la ds fs ac U S u s r i f c )
>> > match='false'
>> > for pattern in "${short[@]}"; do
>> >   if [[ ${whatever} == ${pattern} ]]; then
>> >     match='true'
>> >     break
>> >   fi
>> > done
>> >
>> > Probably the way to go if your list of patterns is determined
>> dynamically.
>>
>> Yeah, but in my experience, a lot of people just *abhor* writing a loop.
>> They'll do anything else.  It's like a religion or something.
>>
>> (Also, you should quote "$pattern" there if each list element is to be
>> treated as a fixed string instead of a glob.)
>>
>> > If the case construct didn't require a | between different patterns in
>> > the same pattern list, then you could just expand ${short[@]} there.
>>
>> We've already learned that you can use an extglob to achieve the desired
>> result (matching a short string against a list of short strings in a
>> single matching step).  Chet even explained why it works.
>
>
> imo long complecated shall work too
>
> but i failed at that :
>
> a=( "' " '$(' ) IFS=\| m='@('${a[*]@Q}\) IFS=$' \t\n'
>
> for : case '$(' in $m) echo ye ;; esac
>
> but
>
> ~ $ echo $m
> '|'$(')
>

this looks right tho :

declare -- m="@(''\\'' '|'\$(')"
from -p

what is this $m
> i dont get it
>
> its supposed to Q escape both elements in a[*] with one | inside separating
>
> .. ?
>
> greets
>
> > > ~ $ echo $short
>> > > li|la|ds|fs|ac|U|S|u|s|r|i|f|c
>>
>> shopt -s extglob
>> shorts="@($short)"
>> case $input in $shorts) echo match;; *) echo no match;; esac
>>     ... or the [[ ]] equivalent.
>>
>> > Using [[  ]] in a for loop is going to be easier to wrap your head
>> > around
>>
>> I'm assuming that writing a simple script that works, is efficient, and
>> is readable is NOT the goal here.  It very rarely is.
>>
>> The goal is most likely one of:
>>
>>  * Do it using a special dedicated feature that looks cool.
>>  * Do it in a clever way instead of an obvious way.
>>  * Make it short.
>>
>> We do get the golfer mentality sometimes, though I don't think xmb falls
>> into that particular group.  Usually it's one of the first two.
>>
>>