See Re^3: How can I read DATA in parent and child? fdopen doesn't help, it's still the same shared seek pointer. *nix doesn't do what you want. If you want to do reads on handles, try this instead.

#!/usr/bin/perl

# https://perlmonks.org/?node_id=1230099

use strict;
use warnings;

open my $x, '<', \do { local $/; <DATA> };

my $who = fork() ? 'p' : 'c';

while( <$x> )
  {
  print "$who $_";
  }

1 while wait > 0;

__DATA__
a
b
c
d
e
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