my $line='id, lang1_bez, lang1_url, lang2_bez, lang2_url, lang3_bez, lang3_url';

my @data=split_line($line);

print join(', ',@$_)."\n" for(@data);

sub split_line
{
  my $line=shift;
  my @ret=();
  my @elm=split(/,\s*/,$line);
  my $id=shift(@elm);
  while(my ($bez,$url)=splice(@elm,0,2))
  {
    my ($lang)=$bez=~/^(.+?)_/;
    push(@ret,[$id,$lang,$bez,$url]);
  }
  return @ret;
}