in reply to Re^3: How to use __DATA__ efficiently, help!
in thread How to use __DATA__ efficiently, help!

Namespacing your __DATA__s is a clever trick, but you're wrong in saying that __DATA__ can't be accessed twice. You can use __DATA__ twice: just rewind it. You need to do so carefully: 

#!/usr/bin/perl

use strict;
use warnings;

my $data_start = tell DATA;
print while (<DATA>);
seek DATA, $data_start, 0;
print while (<DATA>);

__DATA__
hello world

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If you don't bother to tell DATA; ahead of time and instead just seek DATA, 0, 0;, then you effectively print "hello world\n`cat $0`" which isn't what you're expecting.

Is this the best solution to the original poster's problem? Nope. Is it a solution to "how do I re-process this normal filehandle?" Yep.

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Re^5: How to use __DATA__ efficiently, help!
by Anonyrnous Monk (Hermit) on Feb 10, 2011 at 17:32 UTC
    but you're wrong in saying that __DATA__ can't be accessed twice

    This is not what I said.  I said that you can only have one __DATA__ section (per package/file), not that you can only read it once.

    The OP asked "how to use multiple sets of __DATA__", which I understood to mean something like this (also see the OP's sample code) 

    #!/usr/bin/perl

while (<DATA>) { print }

__DATA__
set 1
...
__DATA__
set 2
...

    [download]

    which obviously acts as only one DATA section: 

    $ ./887252.pl
set 1
...
__DATA__
set 2
...

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