Sixtease has asked for the wisdom of the Perl Monks concerning the following question:

Hi, I have a large data structure and I want to dump it to a file. 
use Data::Dumper;
print FILE Dumper $data

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works OK but it creates the dump in the memory, which I'd like to avoid. Is there a way to direct the dump right into the file?

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Re: Stream Dumper
by Arunbear (Prior) on May 23, 2007 at 14:51 UTC
    Yes, you can use Data::Dump::Streamer: e.g. 
    use Data::Dump::Streamer;
use Fatal qw/open/;

open my $fh, '>', 'somefile';

my $x = {cat => [qw/man du/]};

Dump($x)->To($fh)->Out();

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    somefile then contains: 
    $HASH1 = { cat => [
           'man',
           'du'
         ] };

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    Updated example to include intialisation of $x and output.
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Re: Stream Dumper
by tilly (Archbishop) on May 23, 2007 at 14:51 UTC
    Use Data::Dump::Streamer. Glancing at the module, the code likely looks something like: Dump(@data)->To($filehandle)->Out();

    If that doesn't work, then play with it and ask demerphq if you really can't figure it out.

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Re: Stream Dumper
by blazar (Canon) on May 23, 2007 at 14:35 UTC
    works OK but it creates the dump in the memory, which I'd like to avoid. Is there a way to direct the dump right into the file?

    Interesting question. I understand what you mean. I don't know if there's a ready made solution, but if not, then I suppose that D::D builds a string incrementally: so you may examine its code to make it incrementally write to a given file instead.

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      IMO this will be quite nontrivial to do.

      ---
      $world=~s/war/peace/g

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        IMO this will be quite nontrivial to do.

        Appearently the good news are that D::D::S already did that. One more module to bookmark!

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