ag4ve has asked for the wisdom of the Perl Monks concerning the following question:

I'd like to be able to do:
./dat_query '{seek}'
or
./dat_query '{seek}{messages}'

and have code do:
print Dumper($nethist->{seek});
or
print Dumper($nethist->{seek}{messages});

I've been trying:
my $in = $ARGV[0];
my $val = eval '$nethist->$in';
print Dumper($val);

[download]
and the like with no luck

Replies are listed 'Best First'.
Re: eval point in hash ref
by hdb (Monsignor) on May 22, 2013 at 07:20 UTC

    Is this what you want? 

    use strict;
use warnings;
use Data::Dumper;

my $nethist;
$nethist->{seek} = 42;
my $in = '{seek}';
my $val = eval '$nethist->'.$in;
print Dumper($val);

    [download]
[reply]
[d/l]
      Thanks, that's what I was looking for.
[reply]
Re: eval point in hash ref
by LanX (Saint) on May 22, 2013 at 10:10 UTC
    to eval commandline arguments is always prone to code injection

    you might wanna use a simple recursion:

      DB<119> sub dive {
           my $val=shift;
           $val = $val->{$_} for @_;
           return $val;
           }

  DB<120> $nethist
 => { "seek" => { messages => 42 } }

  DB<121> dive ($nethist)
 => { "seek" => { messages => 42 } }

  DB<122> dive ($nethist,"seek","messages")
 => 42

  DB<123> dive ($nethist,"seek")
 => { messages => 42 }

    [download]

    Cheers Rolf

    ( addicted to the Perl Programming Language)

[reply]
[d/l]
Re: eval point in hash ref (Data::Diver)
by Anonymous Monk on May 22, 2013 at 07:13 UTC
[reply]

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