Hash problems in Perl

[thegman]

Is it possible in Perl to create a Hash structure and somehow 'flatten' it so that it may be delievered as an argument to a function without a making a reference to it? The reason I do not want to make a reference is because I want to ditch the real hash to use many times over, and this seems to invalidate the reference. What I need to do is to make a 'stand alone' hash which can be passed around functions without any kind of reliance on any other variable. Possible?

TIA

Garry

 

[goBoating]

'sounds to me like references are the way to go. If you pass a reference to your hash to each routine, then you keep one hash and each routine can operate on it.

Can you sketch out the flow and effect you're trying to achieve? 'hope this helps

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[thegman]

It's OK, I achieved what I wanted, rather than create the reference to the hash in the main subroutine, I passed the hash to a different subroutine, whose only purpose was to make a reference to the hash and pass it back, seems that this will make a unique reference every time, and seemingly make a copy of the hash.

Thanks anyway

 

[goBoating]

#!perl
# it still sounds like you are jumping through a few to many
# hoops.  The following illustrates setting up a hash and 
# passing references to that hash into several trivial 
# sub routines.  Each sub modifies the hash.

use strict;

my %hash = ( color=>'blue');

red(\%hash);
print "RED: $hash{color}\n";

green(\%hash);
print "GREEN: $hash{color}\n";

blue(\%hash);
print "BLUE: $hash{color}\n";

#------------------------------------------------------
# SUBS
sub red  {
  my $hash_ref = shift;
  $$hash_ref{color} = 'red'; 
  }
sub green  {
  my $hash_ref = shift;
  $$hash_ref{color} = 'green';
  }
sub blue  {
  my $hash_ref = shift;
  $$hash_ref{color} = 'blue';
  }

'hope this helps

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