Setting cron job end time

Question

I want to set up a cron job which will execute a command every hour. However, I want that this command should be started at 10 A.M and should run every hour till 4 P.M. This job is to run daily between these times. The command is nothing but a call to a Perl script. Following crontab entry runs fine and invokes the script every hour

* */1 * * * cd path_to_file; perl file.pl > path_to_logs/log.txt

Is there a way to limit the timings of this cron job so that it runs only between 10 A.M and 4 P.M ?

Answer 1

man 5 crontab is your friend. (Your example does not do what you claim it does; /1 is the default skip and therefore redundant, and that spec therefore runs once per minute due to the leading * instead of 0.)

0 10-15 * * * your command here

(I used 15, because it occurs to me that "between 10 and 4" is an exclusive range so you don't want to run at 16:00.)

Answer 2

If you want the script to be run every hour you can do something like this: [code] 00 10,11,12,13,14,15,16 * * * cd path_to_file; perl file.pl > path_to_logs/log.txt [/code]

This means when the minutes hit 00 and the hour hits any of 10 11 12 13 14 15 16 the script will be run

Answer 3

In your Perl script (or in a wrapper for the Perl script), you can use localtime to check the hour and exit if it isn't between 10am and 4pm:

use strict;
use warnings;

my @lt=localtime;
my $hour=$lt[2];

unless($hour>=10 and $hour<=16)
{
  print "Not between 10am and 4pm.  Exiting.\n";
  exit;
}

#put the rest of your code here.