This method will repeatedly check for and process a specially-formatted text file in the location that you specify.
The file is a comma separated file assumed to have four or six fields per line:

    operation, role, user idnumber, course idnumber [, starttime [, endtime]]

where:

* operation - add | del
* role - student | teacher | teacheredit
* user idnumber - idnumber in the user table NB not id
* course idnumber - idnumber in the course table NB not id
* starttime - start time (in seconds since epoch) - optional
* endtime - end time (in seconds since epoch) - optional

It could look something like this:
<pre class="informationbox">
   add, student, 5, CF101
   add, teacher, 6, CF101
   add, teacheredit, 7, CF101
   del, student, 8, CF101
   del, student, 17, CF101
   add, student, 21, CF101, 1091115000, 1091215000
</pre>