Config::Simple Perl module loop through hash

Question

I'm using Config::Simple for my App config, I have created Stats_feeder.cfg that has a block [stats_interval]

[stats_interval]
1m = 60
15m = 900

And my perl script script.pl

my $cfg = new Config::Simple('stats_feeder.cfg') or die Config::Simple->error();

my $hash = $cfg->get_block('stats_interval');

When I run print Dumper($hash); I get

# perl stats_feederv2.pl
$VAR1 = {
          '1m' => '300',
          '15m' => '900',
          '60m' => '3600',
          '30m' => '1800'
        };

I can access values using $val = $cfg->param('1m');

I'm trying to loop through this hash and print keys and values, I have tried the following:

foreach my $key ( keys %$hash )
{

  print "key $key value $hash{$key}\n";

}

I keep getting

Global symbol "%hash" requires explicit package name at stats_feederv2.pl line 42.
Execution of stats_feederv2.pl aborted due to compilation errors.

Answer 1

You are dealing with a hash reference so you need to use $hash->{$key}

An expression like $hash{$key} is attempting to access an element of hash %hash , and the error message you are getting is because that hash doesn't exist. $hash and %hash are completely unrelated

Answer 2

$hash{key} syntax that you use for printing the key's value works when you have a named hash: %hash . In your case, you have an anonymous hash, under a hash reference.

To access the key's value in such a case, you should use this syntax: $hash_ref->{key} . Change:

print "key $key value $hash{$key}\n";

To:

print "key $key value $hash->{$key}\n";