[Omaha.pm] Pulling in a hash via "exec"...FAIL

[Dan Linder]

Dan Linder wrote:

> I thought of that but I couldn't find an comments regarding the differences
>> caused by changing the hash (%fields) to a straight variable ($fields).  I
>> know Perl doesn't do strict casting of variables, but this still looked
>> odd
>> to me.
>>
>
On Thu, Aug 7, 2008 at 9:50 AM, Jay Hannah <jay at jays.net> wrote:

> -ponder-   When you eval this

$fields = {
>  'FIELD1' => {
>                FIRSTNAME => 'Joe',
>                LASTNAME => 'Smith'
>  }
>
> $fields is a hash reference. But in your first post you were scoping and
> returning %fields, which is a hash. Hence your version was scoping and
> returning a hash which had absolutely nothing to do with what your were
> eval'ing.
>
> My change was scoping a scalar $fields, which the eval turns into a hash
> reference, and returns that. I assume this is what you meant to do.


The code I'm working on has had an unknown number of programmers over the
last five years (most field engineers who hacked the code and submitted an
enhancment, not necessiaraly any full-time programmers) so some of the code
in it was probably put in and left there because it worked at the time and
the permissiveness of Perl allowed for the abuse of variable type casting.
:-)

I need to gather a few more customer generated files to test, but I think
changing to the scalar $fields is probably the correct answer.


> You might want to stick these in the top of your program:
> use strict;
> use warnings;
> use diagnostics;


Yes, wonderful additions - unfortunatly I know that Perl will not execute
this piece of code due to failures the "use strict" finds so working through
them is probably the best solution.  (And if not, I can always wrapper
portions of code I can't fix with "no use strict"...sigh)

(I still think eval is evil and you should use Storable. $0.02 -grin-)


Hmmm, this must be a pretty evil program by your measure - it uses eval
quite a bit. :-)

Storable looks like a good solution, but the saved files need to be human
readable like the Data::Dump output - I searched for a flag in the Storable
perldoc but couldn't find one.   (And I don't think that is the intention of
Storable anyway - just provide the ability to store a MACHINE readable
variable not HUMAN readable...)

Dan

-- 
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Satires of Juvenal
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