crontab(1) says -u user Specifies the name of the user whose crontab(5) is to be edited. If this option is not given, crontab examines ``your'' crontab(5); i.e., the crontab of the person executing the command. Note that su(1) can confuse crontab and that if you are running inside of su(1) you should always use the -u option for safety's sake.
Is this actually true? For me, it has always done the expected thing, i.e., run as the user su(1)'d to. Could someone please provide an example where su(1) confuses crontab(1)? Jan