I keep an eye on my apache access logs to see what kind of traffic my site gets and why it gets here. It seems that a non-trivial number of searches are for 'vpn over ssh' and similar variants. These land at the ppp over ssh article.

New versions of openssh have built-in support for tunneling, and do not require ppp at all. Seeing as how I've never really used this new feature, and there's a nontrivial number of searches ending up on the ppp-over-ssh article, I think it's time to write a little article on how to use the new openssh built-in tunneling.

Stay tuned...

For pimp, I want to be able to search a specific column, say, artist, without needing multiple fields for searching. The ability to specify more advanced searches than simple keywords is quite useful. How do we leverage this on the client and turn a search query into a set of key-value pairs?

I must confess I was hesitant to put this kind of logic into Javascript instead of Python. Furthermore, it makes me feel a little uneasy using /foo/ in anything other than Perl. Nonetheless, doing this in Javascript was simple and it's still fast (as it should be).

The particular type of query I want to parse come in the following (hopefully intuitive) formats:

• foo
• artist:Eminem
• album:"Across a Wire"
• artist:"Counting Crows" album:august

The following code does this for me. The parse_query function will return a dictionary of query terms. Values are lists.

Here's an example:

Query

rain baltimore artist:"Counting Crows" album:august

Results of parse_query

    { "artist": ["Counting Crows"],
      "album": ["august"],
      "any": ["rain", "baltimore"],
    }
  

I take the dictionary returned and pass it to jQuery's $.post function to execute an AJAX (I hate that term, it's such a misnomer these days) request. Here's the code:

query_re = /(?:"([^"]+)")|(?:\b((?:[a-z:A-Z_-]|(?:"([^"]+)"))+))/gi,

function parse_query(string) {
  dict = {}
  while (m = query_re.exec(string)) {
    val = (m[1] || m[2]).split(":",2)
    if (val[1]) { key = val[0]; val = val[1]; }
    else { key = "any"; val = val[0]; }

    val = val.replace(/"/g,"");

    dict[key] = dict[key] || [];
    // the following should be .append(val) but 
    // I don't think javascript lists have them
    dict[key][dict[key].length] = val;
  }

  return dict;
}