Not a random number, but at least a DIFFERENT number can be generated by the time() function. This returns the number of seconds since Jan 1st 1970 00:00:00 hrs.
This counter changes every second, and you could make it appear more random. How complicated the algorithm needs to be depends upon how many unique outputs are required. E.g. If the outputs are "yes", "no" and "maybe", which just need to appear random, then the last digit can be used to point to an offset (modulo 9) from the present position in a string of 9 characters "y", "n" and "m" e.g. $sequence="nymynmmny".