sub func {
  local $_;   # THIS IS THE KEY LINE YOU NEEDED
  open(READ, "< test.txt");
  while(<READ>) {
    #   print;
  }
  close READ;
  return;
}

# outputs the final line w/o a problem
Files: ree ree1 ree2
$VAR1 = [
          'ree',
          'ree1',
          'ree2'
        ];
The file is ree
The file is ree1
The file is ree2
Files: ree ree1 ree2

##</code><code>##

use strict;
use warnings;

sub forEveryOther(&@) {
  my @aData = @_[1..$#_];
  my @aResults;

  local $_;
  for (my $i=0; $i < $#aData; $i+=2) {
    $_ = $aData[$i];
    push @aResults, $_[0]->();
  }
  return @aResults;
}

##</code><code>##

my @people = (bob => 53, peter => 200);
my @hello = forEveryOther { "Hello, $_\n" } @people;
print @hello;

# outputs
Hello, bob
Hello, peter