@content= (@content, <FH>);

##</code><code>##

push @content, <FH>;

##</code><code>##

use strict;
use warnings;

use Benchmark q{cmpthese};

my @files = grep { -f } <spw59*>;

my $rcCopy = sub
   {
       my @content = ();
       foreach my $file ( @files )
       {
           open my $fh, q{<}, $file
              or die qq{open: $file: $!\n};
           @content = (@content, <$fh>);
           close $fh
              or die qq{close: $file: $!\n};
       }
       
       return \@content;
   };

my $rcPush = sub
   {
       my @content = ();
       foreach my $file ( @files )
       {
           open my $fh, q{<}, $file
              or die qq{open: $file: $!\n};
           push @content, <$fh>;
           close $fh
              or die qq{close: $file: $!\n};
       }
       
       return \@content;
   };

cmpthese (-60,
   {
      Copy => $rcCopy,
      Push => $rcPush,
   });

##</code><code>##

       Rate  Copy  Push
Copy 2.32/s    --  -94%
Push 41.9/s 1710%    --