#eval { eval { "$config->{client}->{1}->{file}->{1}->{executeInternal}
+" } };
##</code><code>##

eval ( eval { "$config->{client}->{1}->{file}->{1}->{executeInternal}
+" } );
##</code><code>##

#!/usr/bin/perl -w

use warnings;
use strict;
use XML::Simple;

# Getting the ref using XMLIn
my $config = XMLin("test.xml", forceArray=>[qw(config client file)], suppressEmpty=>undef);

# Print the actual subroutine and call from XML
print "The actual code in the XML is:\n";
print $config->{client}->{1}->{file}->{1}->{subroutines}->{callInternalSub},"\n";
# Eval the sub - works fine - contains a mySub() call without arguments
print "EVALing the actual code in the XML. Works fine if my call is simply mySub() without arguments. \n";
eval (qq"{" . $config->{client}->{1}->{file}->{1}->{subroutines}->{callInternalSub} . "}");
print "\n";

#Direct call to EVALed sub - works fine
print "Direct call to the EVALed sub without arguments works fine. \n";
mySub("hello world");
print "\n";

# Print a bunch of stuff
print "Print a bunch of stuff:\n";
print "$config->{client}->{1}->{file}->{1}->{executeInternal}\n";
print eval { "$config->{client}->{1}->{file}->{1}->{executeInternal}" },"\n";
print eval qq{"$config->{client}->{1}->{file}->{1}->{executeInternal}"};
print "\n\nNow trying the actual eval:\n";

eval (qq"{" . $config->{client}->{1}->{file}->{1}->{executeInternal} . "}");
# As expected, the line below works too (not because of the EVAL) - 
#eval (qq"{" . mySub("hello world") . "}");
# Do I have to escape my "" in my XML file? If I simple call mySub() in the XML, it works fine.
# I tried a few things (\,\\) to no avail. 

# The line below will cause an error to be thrown saying "Useless use of string in void context at test.pl line XX."
#eval { eval { "$config->{client}->{1}->{file}->{1}->{executeInternal}" } };
# However, if I replace the "{}" with "()" it doesn't throw that error. Could someone please explain why using the 
# block form does this?
#eval ( eval { "$config->{client}->{1}->{file}->{1}->{executeInternal}" } );

##</code><code>##

<config>
	<client name="1">
		<file name="1">
			<executeInternal>mySub(\"Hello World\")</executeInternal>
			<executeInternalWORKS>mySub()</executeInternalWORKS>
			<subroutines>
				<callInternalSub>
				sub mySub() {
					my $message = "blah";
					my $message = shift; #broken version
					print "Message- $message\n";
					print "Caller-> ",caller,"\n";
				}
				mySub();
				</callInternalSub>
			</subroutines>
		</file>
	</client>
</config>