If the server is not specified, xtbot will attempt to connect to a server on localhost (127.0.0.1). If no server is running on localhost, xtbot will exit with an error message.
xtbot connects to an xtris server, registers itself as a bot, and simulates a game of Tetris whenever a human player hits 'play'.
The current version of xtbot uses a pretty good decision algorithm, which usually does several thousand lines before losing, when playing on its own. When playing against a bot, though, the main limiting factor is the speed, whic is why xtbot purposefully waits a little before dropping each brick, so that humans can compete speed-wise.
xtbot is started automatically by xtris, with the option '-quiet', when a player presses the 'bot' button.
Running copies of xtbot can be killed either by clicking on their name from an xtris window, or by killing the process.
It is fairly easy to adapt xtbot to make your own bots based on your favorite decision algorithms. For this the easiest way is to change the decision function in decide.c while keeping the rest of the bot's skeleton (in xtbot.c). See the comments in decide.c, decide.h and xtbot.h for details about the interface between these. Alternatively, the protocol between the client and the server is described in detail in the file PROTOCOL, so you can make completely independent bots.
The values for the coefficients that xtbot uses now were obtained with a genetic algorithm using a population of 50 sets of coefficients, calculating 16 generations in about 20 hours on 20-odd Sparc workstations. This improved the average number of lines from 10,000 to about 50,000. The code used for this isn't nearly clean enough to distribute in a release. If you're interesed, please e-mail the author privately.