Rotating .sig files among a few standards is fairly simple.  This
is just one of many ways to accomplish the feat.


 1) create a directory to hold the standard sigs.
    I use ~/sigs/

 2) create a bunch of standard sig files with the
    desired tag lines.  Name the files sig.[0-9]

 3) seed the current sig file
	
	$ echo 0 >sig.current

 4) create the rotate_sigs script to do the dirty work.
    Don't forget to make it executable!

	$ chmod +x rotate_sigs

    Here's the contents of my rotate_sigs:


	#
	#  rotates Netscape sig.txt among a few standards
	#
	uname -a > sigs/sig.9
	uptime >> sigs/sig.9
	#
	CURRENT=`cat sigs/sig.current`
	let CURRENT=$CURRENT+1
	if [ $CURRENT -ge 10 ]; then
		CURRENT=0;
	fi
	cp sigs/sig.$CURRENT ~/netscape/users/brianc/sig.txt
	echo $CURRENT > sigs/sig.current

    The script does several things.  First it creates sig.9
    with the latest uptime.  Next the current sig number is
    obtained from the sig.current file and incremented.  If 
    necessary, this gets reset to zero. Then, the selected
    sig file (sig.$CURRENT) is copied to the mailer sig
    location.  Finally, the sig.current file is updated.

 5) run the script via cron a few times an hour like this-

        $ crontab -l
        0,15,30,45 * * * * /home/brian/sigs/rotate_sigs