Script has gone into an infinite loop-- is it possible to save my world files?

I think I accidentally made a Lua script which might go in an infinite loop. MUSHclient became unresponsive (you know, the whole hourglass mouse cursor thing.)

Once a script has gotten stuck in an infinite loop, is it possible to escape it (maybe like bash's ctrl+c) without ending the mushclient process and losing all unchanged settings in the world files?

No, I don't think so. If your script has gone into a loop it hasn't returned to the client and thus it isn't processing any keystrokes or mouse clicks.

I know it is a bit late, but for next time, look at this post:

http://www.gammon.com.au/forum/?id=6534

That describes how, for Lua anyway, you can make scripts break out of long loops.