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
do_calc (1,2,3);

sub do_calc
{
   print "In subroutine: do_calc()\n";
   print "I am: ",whoami,"\n\n";
   do_sub_calc();
}

sub do_sub_calc
{
   print "In subroutine do_sub_calc()\n";
   print "I am: ", whoami(),"\n";
   print "I was called by: ", whowasi(),"\n";
}

__END__
prints:
In subroutine: do_calc()
I am: main::do_calc

In subroutine do_sub_calc()
I am: main::do_sub_calc
I was called by: main::do_calc
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