Uturn is a program written in standard C to check incoming VGA Planets trn
files. The only check it does is a comparison against the expected date-time
stamp. If called from within a procmail shell script, players can be sent a
feedback notice almost immediately after receipt of their turn. 

Q&A:

How do I check a file?

	- Usage: "uturn <filename>", or "cat <file>|uturn". The output of
	program can be piped directly to mail like so:
		"cat player1.trn| uturn | mailx -s "turn received" player1
	Assuming player1 is an alias to the real player.
	On suns, you may need to replace mailx with mail, or Mail.
	System V compatible unixs should have a mailx.

So, does this mean I need to keep my host files on the mail server?

	- No! The only file needed is the current nextturn.hst, which contains
	the date-time stamp, and the next turn number. It's expected to be in
	the current directory. e

Does the example script mail back to whoever sent the turn?

	- No. I have aliases set up in my $HOME/.mailrc for player1, player2,
	etc. This only works if I host one game. The example script needs
	work to support multiple games. formail could be used to return to
	whoever sent the turn, but this is less secure. By returning to a
	fixed address, the player can tell if someone else tries to submit
	a turn with their player number! 

Is that the only security possible?

	- No. The player number is also contained inside the file. A much
	better solution would be to set up a password system, perhaps even
	using the internal password changes! But that's a future project.

Can I run this under dos?

	- Yes, it compiles under dos just fine.




Any more questions, mail me at dboynton@clark.net.

Dave Boynton

