Re: Use of $@

[alex xmb ratchev]

On Tue, Feb 21, 2023, 12:37 PM alex xmb ratchev <fxmbsw7@gmail.com> wrote:

>
>
> On Tue, Feb 21, 2023, 11:28 AM Christof Warlich <cwarlich@gmx.de> wrote:
>
>> Hi,
>>
>> just to improve my bash skills: The following functions prints the array
>> index of a value if found:
>>
>> index() { local e="$1"; shift; local a=("$@"); for i in "${!a[@]}"; do
>> [[ ${a[$i]} != $e ]] || { echo $i; break; }; done; }
>>
>
> here is a substitude version , speed is in question , but i wouldnt learn
> anything without writing such ..
>

sorry this termux gmail doesnt paste well ..

u.1 http://0x0.st/HsSf.txt

cat u.1 ; printf \###\\n ; bash u.1
> unset -v a f r R                                              a=( 0 1 2 3
> ) f=2 r=a
>
>  fidx() { declare -gn res=$3 ; declare f c ; declare -a r ; unset -v f c r
> mapfile -d '' c < <( declare -p "$1" )
> r=${c//=\"$2\"/$'\1'}
>  [[ $r == $c ]] &&                                            return
> r=${r%%$'\1'*} r=${r##*\[} res=${r%]}         }
>
>
> fidx $r $f R
> declare -p R
> ###                                                           declare --
> R="2"
>
>
> Thus, with e.g.: myarray=("a" "bc" "my value" "z")
>>
>> I get:
>>
>> $ index "my value" "${myarray[@]}"
>> 2
>>
>> as expected. The only thing that bothers me is that I couldn't get away
>> without the intermediate assignment of $@ to a new array (a): Is there
>> really no way to avoid that, i.e. directly using $@ in the for-loop?
>>
>> Cheers,
>>
>> Chris
>>
>