Shell Programming and Scripting

Hello Everybody..

I've written the script that kick off through CRON job and kill itself by specific time.

I've start time and end time specify in env file.
i.e
START_TIME=1500 (03:00 PM)
END_TIME=0600 (06:00 AM)

It always works good if my START_TIME is before midnight and my END_TIME is after midnight.

I'm using follwing if condition to terminate my script.
if [ $CURRENT_TIME -gt $START_TIME ] || [ $CURRENT_TIME -lt $END_TIME ];

But if I wanted to change my START_TIME and END_TIME to like
START_TIME=1300 (01:00 PM)
END_TIME=1530 (03:30 PM)
then it's not follow the logic and script will run forever.

When job kick off through CRON then script will check that kick off time is after the START_TIME and before the END_TIME.


Please help me out with this!!!

Thanks in advance.

maybe you can use epoch time?

Code:

now=`perl -MTime::Local -le'print timelocal localtime'`

gives the current time in terms of seconds since 1970. So you can terminate your script in a spesific time. 1 hours is 3600 seconds so lets say to finish your script after 2 hours you have to calculate the current time again and compare it with (now+7200)

i just wanted to give an idea

regards

---------- Post updated at 11:11 PM ---------- Previous update was at 11:10 PM ----------

Code:

/usr/bin/truss /usr/bin/date 2>&1 |  nawk -F= '/^time\(\)/ {gsub(/ /,"",$2);print $2}'

also gives epoch time.

Code:

perl -e 'print time'

/bin/date +%s

Those two are more concise, and accomplish the same thing ( return the seconds since the epoch 00:00:00 Jan 1, 1970 GMT, not counting leap seconds ).

The date command is GNU date 7.2 on Linux. Use Perl, if you are worried about portability of /bin/date

Here is a simple example of a perl script to do what you want:

Code:

my $begin_time = time;
my $offset = 10; # number of seconds
do { 
  print "foo\n"; 
  sleep 1; 
} while ( time < ($begin_time + $offset) );

this grabs the current epoch time and then executes the code in the do() block ( in this case, prints "foo" once every second ). It keeps doing this for 10 seconds total.

What you need to do is put the start time in as a field in your crontab which runs this job, and then calculate the offset in seconds from that time.

In the example you gave this is 60 seconds * 60 minutes * 15 hrs, or 54,000 seconds. that is what you should set $offset to.

I would actually set it, not "54,000" but the equation, as it helps you to see what is going on:

Code:

my $offsest = 60 * 60 * 15;  # easier to understand this is 15 hours

Hope that Helps

Some versions of date don't have the %s (Solaris is one) modifier. Not all UNIX flavors have truss. I would recommend using the perl method deindorfer posted.

Thanks for the reply deindorfer!!!
I did understood your logic and it'll work if i only have to control the end time.
I'm sorry I mention CRON actually this job run through CA7 scheduler which is not in my control. CA7 will always kick off the job at specific time but as requirement I’ve to check in my script that kick off time is after the START_TIME.
As you said that convert the END_TIME in second (i.e. 60 * 60 * 15 = 54000 sec)
that means my job will run for 54000 seconds.
For example in my environment file I’ve
START_TIME=2100
END_TIME=0600

If I convert my END_TIME in seconds then it'll only run for 6 hours.
The user will put actual time to end the script they won't put the total hours to run the script.

I guess I may need to get the difference between START_TIME and END_TIME to get the total hours and then run the script for that total hours.
But I’m still stuck with that START_TIME comparison.

I really appreciate for the Help!!!