use strict;
use warnings;
use Config::IniFiles;
my %args;               

my $global_ini_data = Config::IniFiles->new( -file => "test.ini" );

my $regex = $global_ini_data->val( 'client1', 'rename' );

my $filename = "201306051200foobar.dat";

print "REGEX: $regex\n";
print "BEFORE: $filename\n";

# Uncomment each method individually to test 

# Method 1: doesn't work
#$filename =~ qr($regex);

# Method 2: doesn't work
#$filename =~ $regex ;     

# Method 3: doesn't work
#$filename = modify($filename, sub { $_[0] =~ $regex });

# Method 4: doesn't work (not global)
#my ($before, $after) = $regex =~ m{/(.*)/(.*)/};
#$filename = replace($filename, $before, sub { $after }, 0);

# Method 5: doesn't work (global)
#my ($before, $after) = $regex =~ m{/(.*)/(.*)/};
#$filename = replace($filename, $before, sub { $after }, 1);

# Method 6: works, but hardcoded and not in INI; not scalable
$filename =~ s/(\d{2})(\d{2})(\d{4})(.*)/$3$2\.$4/;    

# End Methods test

print "AFTER: $filename\n";
exit;

sub replace {
    my($string, $find, $replace, $global) = @_;
    unless($global) {
        $string =~ s($find){ $replace->() }e;
    } else {
        $string =~ s($find){ $replace->() }ge;
    }
    return $string;
}

sub modify
{
  my($text, $code) = @_;
  $code->($text);
  return $text;
}