Re: test -v for array does not work as documented

2020-02-23 Thread Chet Ramey 
On 2/21/20 3:31 AM, pepa65 wrote:
> On 21/02/2020 02.37, Chet Ramey wrote:
>> It's unset because it doesn't have a value, but it retains the `local'
>> attribute so it stays local if subsequently assigned one.
> 
> Is there any reason the local attribute cannot be unset? If it would be
> possible then the "declare/typeset -p" would return 1 when the variable
> doesn't exist.

There have been several umm...passionate discussions about this. The idea
is that a local variable that's unset should stay local (and unset) until
the function returns instead of `uncovering' a variable at a previous
scope.

Think about dynamic scoping and its effects on variable visibility.

> By the way, it seems that `local -p var` doesn't work like 'declare -p
> var` even though `help local` suggests it should.

How so? Do you mean that declare -p var in a function will show different
variables?

-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRUc...@case.eduhttp://tiswww.cwru.edu/~chet/

Re: test -v for array does not work as documented

2020-02-23 Thread pepa65 
On 23/02/2020 23.27, Chet Ramey wrote:
> On 2/21/20 3:31 AM, pepa65 wrote:
>> By the way, it seems that `local -p var` doesn't work like 'declare -p
>> var` even though `help local` suggests it should.
> 
> How so? Do you mean that declare -p var in a function will show different
> variables?

See this output:

localvsdeclare(){
  local var
  var=42
  unset var
  echo -n '"declare -p var":'
  declare -p var
  echo -n '"local -p var":'
  local -p var
}

localvsdeclare
"declare -p var": declare -- var
"local -p var":

Peter

Re: test -v for array does not work as documented

2020-02-23 Thread Chet Ramey 
On 2/23/20 11:36 AM, pepa65 wrote:
> On 23/02/2020 23.27, Chet Ramey wrote:
>> On 2/21/20 3:31 AM, pepa65 wrote:
>>> By the way, it seems that `local -p var` doesn't work like 'declare -p
>>> var` even though `help local` suggests it should.
>>
>> How so? Do you mean that declare -p var in a function will show different
>> variables?
> 
> See this output:
> 
> localvsdeclare(){
>   local var
>   var=42
>   unset var
>   echo -n '"declare -p var":'
>   declare -p var
>   echo -n '"local -p var":'
>   local -p var
> }
> 
> localvsdeclare
> "declare -p var": declare -- var
> "local -p var":

Yes, it's always been this way. This behavior dates to March, 1995,
literally to the time I added `-p'. The reason for not making `local -p'
work the same has been lost to time, so let's try making it the same
and see what happens.

-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRUc...@case.eduhttp://tiswww.cwru.edu/~chet/

Re: ${!variable@operator} does not work for variables without values; inconsistencies between present and absent [@] for @A and @a

2020-02-23 Thread Chet Ramey 
On 2/20/20 7:34 PM, Arfrever Frehtes Taifersar Arahesis wrote:

>> Same answer as previously: maybe it should display the attributes
>> even thought the variable is unset.
> 
> Yes, I think that @A, [@]@A, @a and [@]@a should work for unset variables.

OK, we'll try that and see how it works.

-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRUc...@case.eduhttp://tiswww.cwru.edu/~chet/