I second ikegami's comment: what is the purpose?

With Perl there are amazing things that you can discover about what is going on in a sub. Just some simple example code is shown below. I am unsure as to what you want.

#!/usr/bin/perl -w
use strict;

print "testing main\n";
x();

sub x
{
  print "In sub x\n";
  print "   I am:           ", WHOamI(), "\n";
  SubLevel2();
}

sub SubLevel2
{
  print "in sub SubLevel2\n";
  print "   I am:           ", WHOamI(), "\n";
  print "   I was called by ", WHOwasI(),"\n";
}

sub WHOamI  { (caller(1))[3] };  #returns name of the 
                                 #sub that called this sub
sub WHOwasI { (caller(2))[3] };  #returns name of the parent of 
                                 #the sub that called this sub

__END__

#prints
testing main
In sub x
   I am:           main::x
in sub SubLevel2
   I am:           main::SubLevel2
   I was called by main::x
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