UNIX for Dummies Questions & Answers

This goes deeper into the date thing. I want to be able to check the date and time stamp in or on a file to see what the time span is.

We have a job that runs several times an hour - kicked off through cron based on a trigger file. We want to keep track of each run and check the time between runs for reasonbleness because the job can hang and not notify anyone. Right now we have someone watching the job during peak hours and manually determining that it has been in the run state too long. I would like to automate the reasonbleness check for automated notifies.
(the hanging is out of our control so we need to automate the monitor process)
We put a time stamp in a log of when the job starts, so we already have that peice. What I don't know how to do is manipulate date and time down to minutes.

THANKS!

Check the man page for the `date` command.
Most of the time, it will follow a format similar to the following:
date +%H:%M:%S - This will give a format of the following:
07:09:59

But the most help you'll probably get is:
man date

thank you , I guess I should have been more specific. I know how to get the date and time.
I need to obtain the time difference between the start times of my jobs.
ie. the job kicks off at 8:30:00 then again at 8:47:00 I need to calculate the difference between these two times. then I can do a reasonbility check for the time span - if the time span is greater than 15mins, I want to send a notify to a pager. I know how to send the notify, what I am looking for is how to determine the time span / difference.

thanks

why not toss another date time stamp w/ something signifiing then end of the run. This will alow you to do 2 things.

1) let you know how long it took to do the job in the first place.
2) let you know the time between jobs.

ie:

==== Job Begins date-time-stamp ====
what ever you do to your files
......
==== Job EOF date-time-stamp ====

I have that information.
I am not looking for logical approaches....
I am looking for the technical way of how do I subtract the start time from the end time to get the time span?

I have the time 08:30:00 how do I write script code to subtract it from 08:47:00 ???????????

I can awk out the hour and minutes and seconds and work that way then put it all back together, but I want to know if anyone has an easier way to calculate elapsed time.

Well, you can take the hour, multiply by 60, then add the minutes to get minutes after midnight. But how on earth does comparing the start times of two jobs help you know when one is hung? And why worry about the start times of jobs started via cron anyway?

If want to detect a job that runs longer than 15 minutes, just use a shell wrapper:

Code:

#!/usr/bin/ksh
job_that_might_hang &
pid=$!
sleep 900
if kill -0 $pid 2>/dev/null ; then
   echo background job is still running
else
   echo background job finished
fi
exit 0

do something like this:

Code:

#start of job
echo $(date +%H%M%S) >> /some/place/log
#
# job here
#
echo $(date +%H%M%S) >> /some/place/log
#now, to compare
date_1=$(tail -2 /some/place/log | head -1)
date_2=$(tail -1 /some/place/log)
check_time=$(expr ${date_2} - ${date_1})
if [ "$check_time" -gt "1500" ] ; then
     echo "Uh oh!" | mail mizzgail -s "your process got stuck"
fi

This isn't very proactive, but it would be fairly easy to construct a script that could poll, comparing the current time (in a similar fasion as above) to the start time. Also, instead of mail, you could send a message directly to a users console... etc...

Hope that helps.