difference in time for syslog cron script

[pcorchary]

I am in search of a portable (sh) method for differential times, that includes dates. Essentially I need an accurate way to determining what time it was "N" minutes ago ...

The core problem is to scavange Solaris syslog /var/adm/messages for certain things, but only from the entries of of the past N minutes (probably 10 minutes), via a cron job ...

I've seen some fancy perl that i can't use. awk might do it, but I can't quite gte it working. And I've seen lots of DATE difference scripts, but I really need TIME dfference, and of course since I'm working with cron, I need to compare to that date format ... "May 8 01:59:59".

ANY help appreciated.

 

[Salem]

Do these log files get deleted regularly?

An alternative would be to record the last line processed in a file, so that when you next run the program, you can skip all the lines in the log file which you've processed already.

#!/bin/awk -f
BEGIN {
# where did we get to last time?
getline prev < &quot;prev.txt&quot;
}
FNR > prev {
# do stuff with lines appended since last time
}
END {
# record where we got to for next time
print FNR > &quot;prev.txt&quot;
}

 

[pcorchary]

The log files do NOT get trimmed -- the rotate semi-regularly, but /vart/adm/messages in our environment are kept as messages.0, messages.1, etc. for at least 6 months.

Recording that last line processed is an interesting thought. I also considered using /bin/logger to write a marker line into the log itself for the script to operate from.

Ideally I'd still like to go by the date stamp