use strict;
use warnings;

my $fname = 'foo';
my $pkg = __PACKAGE__;
if(my $code = $pkg->can($fname)){
	$pkg->$code(1,2,3);
}
else{
	die "No code for function '$fname'\n";
}

sub foo{
	print "this is sub foo in package 'main', args: @_\n";
}