sub func1 {

  my (@fileContent,@temp, @comment);
  my $contentFh = &openFile($file1);

  while (my $line = <$contentFh >) {
    ...
    push(@fileContent,&func2($line));
    ...    
    }
  }
  close($contentFh);
  return \@fileContent;
}

sub func2 {

  my ($user) = @_;
  my @groupsFile;
  my $groupsFh = &openFile($file2);

  @groupsFile = <$groupsFh>;
  close($groupsFh);
  ...
  return @groupsFile;
}