Re: new user questions and issues

[Kannan Varadhan <kvaradhan3@gmail.com>]

Thank you Eric.

I had worked out other ways of achieving #1, just wanted to learn if there was a good way to do it.

The others, I get.

Thanks,

Kannan

> On May 6, 2015, at 1:50 PM, Eric Cook <llua@gmx.com> wrote:
> 
> I can snipe the easier to explain ones.
> On 05/06/2015 01:37 PM, Kannan Varadhan wrote:
> 
>> Issue #1:  Programmatic Scripting, how to?
>> 
>> I would like to do the following:
>> 
>> for var in path infopath manpath cdpath ; do
>>    typeset -agU $var
>>    local capsvar
>>    capsvar=$(echo $var | tr 'a-z' 'A-Z')
>>    $var=( $(echo ${$capsvar} | sed 's/:/ /g') )
>> done
>> 
>> But this does not work, because ${$capsvar}  gets me a zsh: bad substitution.
>> Is there any way to achieve this in zsh?
>> 
> You can use the parameter expansion flag P. ''${(P)capsvar}''
> 
> With the exception of infopath, The arrays you are trying to define are
> already created and tied to the uppercase scalar parameters.
> Any change made to one is reflected in the other.
> 
> echo by default interprets c string escapes, you can disable that with
> the -E option.
> 
> You could avoid the command substitution with the parameter expansion
> flag U ''capsvar=${(U)var}'' to change the case of the value.
> 
> $var=(...) is also an error. ''set -A $var element1 element2 ...'' will
> allow you to indirectly set arrays
>> Issue #2.  Overridden local variables get echoed?
>> 
>> ~ 5% cat lib/zsh/test2                                                  9:55:52
>> function test2 
>>    print why is the previous value echoed when a local variable is 'overridden?'
> It actually happens when you use typeset, local, etc. on a parameter
> that is already defined. You can use the option TYPESET_SILENT option to
> silence it.
> 
> from the typeset section of zshbuiltins(1):
> If  the  shell  option  TYPESET_SILENT  is  not  set, for each remaining
> name that refers to a parameter that is set, the name and value of the
> parameter are printed in the form of an assignment.  Nothing is printed
> for newly-created parameters, or when any attribute flags listed below
> are given along with the name.  Using `+' instead of minus to introduce
> an attribute turns it off.
> 
> 
> Pretty sure #3 and #4 is due to how typeset creates a local parameters
> when used in a function. So typeset -U PATH create a new parameter
> without a value, with the -U attribute.