Webservice requests are any that refer to filename "search.pz2". Arguments
are GET-style parameters. Argument 'command' is required and specifies
command. Any request not recognized as a webservice request as described,
are forwarded to the HTTP server specified in option -p.

Commands:

init

Initializes a session. Returns session ID to be used in subsequent requests. Example:

search.pz2?command=init

Response example:

<init>
  <status>OK</status>
  <session>2044502273</session>
</init>

ping

Keeps a session alive. An idle session will time out after one minute. The
ping command can be used to keep the session alive absent other activity. It
is suggested that any browser client have a simple alarm handler which
sends a ping every 50 seconds or so once a session has been initialized.

Example:

search.pz?command=ping&session=2044502273

Response example:

<ping>
  <status>OK</status>
</ping>

search

Launches a search, parameters:

session
query

Example:

search.pz2?session=2044502273&command=search&query=computer

Response example:

<search>
  <status>OK</status>
</search>

stat

Provides status of ongoing search. Parameters:

session

Example:

search.pz2?session=2044502273&command=stat

Output:

<stat>
  <hits>7</hits>                   -- Total hitcount
  <records>7</records>             -- Total number of records fetched
  <clients>1</clients>             -- Total number of associated clients
  <unconnected>0</unconnected>     -- Number of disconnected clients
  <connecting>0</connecting>       -- Number of clients in connecting state
  <initializing>0</initializing>   -- Number of clients initializing
  <searching>0</searching>         -- ... searching
  <presenting>0</presenting>       -- ... presenting
  <idle>1</idle>                   -- ... idle (not doing anything)
  <failed>0</failed>               -- ... Connection failed
  <error>0</error>                 -- ... Error was produced somewhere
</stat>

show

Shows records retrieved

parameters:

session
start      -- 0-indexed!!
num        -- default=20
block      -- 0 or 1

If block is set, the command will hang until there are records ready
to display. Use this to show first records rapidly without requiring rapid
polling.

Example:

search.pz2?session=2044502273&command=show&start=0&num=2

Output:

<show>
  <status>OK</status>
  <merged>6</merged>
  <total>7</total>
  <start>0</start>
  <num>2</num>
  <hit>
    <title>How to program a computer, by Jack Collins</title>
    <count>2</count> <!-- Number of merged records -->
  </hit>
  <hit>
    <title>
  Computer processing of dynamic images from an Anger scintillation camera :
  the proceedings of a workshop /
    </title>
  </hit>
</show>