These options edit the files /usr/lib/cron/.proto
(for at) or /usr/lib/cron/.proto.b
These files are placed at
the start of the shell script formed for
all at and batch jobs.
This script must conform to the usual
/bin/sh syntax and contain some variables
particular to the prototype file.
These variables are:
Current directory of the user at the time of submission.
ulimit for the user at the time of submission.
umask for the user at the time of submission.
Time (in seconds past 1 Jan 1970) that the script is run.
Replaced with the entire script that the user submits. Normally,
this appears last in the file, after the prologue that you set up.
If you decide to include information after this variable,
the shell script may exit before reaching it.