Re: Use of $@

[alex xmb ratchev]

On Tue, Feb 21, 2023, 12:38 PM alex xmb ratchev <fxmbsw7@gmail.com> wrote:

>
>
> 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
>

a cleaned up , expanded version
u.1 http://0x0.st/HsSO.txt
cant assure speed

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
>>>
>>