# Reads in
#  -filehandle: file to be moved in
#  -scalar: current line (0 is before first row)
#  -scalar: wanted line (beginning, so if read increment too)
sub Set_line (\*\$\$) {
  my $fh_r=shift @_;
  my $cur_r=shift @_;
  my $row_r=shift @_;

  if ($$cur_r>$$row_r) {
    seek ($$fh_r,0,0);
    $$cur_r=0;
  }
  while (!(($$cur_r)==$$row_r) && $_ ne "") {
    $_=readline($fh_r);
    $$cur_r++;
  }
  return;
}