sendmail, 4th Edition

Using cron for Daily and Weekly Statistics

The mailstats program prints the contents of the statistics file, but it does not zero (clear) the counters in that file. To zero that file, you need to truncate it. One easy way to do this is:

# cp /dev/null /etc/mail/statistics

When sendmail discovers an empty statistics file, it begins gathering statistics all over again. One use for truncation is to collect daily reports from mailstats. Consider the following simple shell script:

#!/bin/sh
ST=/etc/mail/statistics
MS=/usr/etc/mailstats
if [ -s $ST -a -f $MS ]; then
        $MS | mail -s "Daily mail stats" postmaster
        cp /dev/null $ST
fi
exit 0

When run, this script checks to see whether a nonempty statistics file and the mailstats program both exist. If they do, mailstats is run, printing the statistics, which are then mailed to postmaster. The statistics file is then truncated to a size of zero. Such a script could be run once per night using the cron(8) facility with a crontab(5) entry like this:

0 0 * * * sh /usr/ucb/mailstats.script >/dev/null 2>&1

Here, mailstats.script is the name given to the earlier shell script, and the 0 0 causes that script to be executed once per day at midnight.

Moving and renaming the statistics file allows you to automatically collect daily copies of that file. Consider the following variation on the previous shell script:

#!/bin/sh BASE=/etc/mail ST=statistics MS=${BASE}/stats_arch if [ -d $BASE ]; then cd $BASE if [ -s $ST -a -d $MS ]; then mailstats | mail -s "Daily ...