I guess you could if you really want to.
I can't see why you would .
You need to dynamically change the file with the ip in it
Maybe there is another way but I don't know what it is.
I guess you could echo the contents of a file containing everything except the ipaddress in it.
then append the ipaddress that you randomly select to the file
using >>
Well I think I have finally went off the deep end here with this
create a count file and put 1 into it.
when the user logs off look at this file and echo the ipaddress associated with 2 into the options file, then update the contents of the count file to 2
etc...