So I made this so it would send a command at Sunday night at 11:59pm, 1 minute before Monday, but for some reason it doesn't work. I even changed the * * 7 to 0.
59 23 * * 7 screen -S skyblock -p 0 -X stuff "mangdelp default essentials.fly ${printf \\r)"
Your syntax is incorrect.
It should be like this:
59 23 * * 0 screen -S skyblock -p 0 -X stuff \"mangdelp default essentials.fly ${printf \\r)\" >/dev/null 2>&1
minute(s) hour(s) day(s) month(s) weekday(s) command(s)
The fields are
separated by spaces or tabs. The first five are integer patterns and
the sixth is the command to be executed. The following table briefly
describes each of the fields.
Field Value Description
minute 0-59 The exact minute that the command sequence executes
hour 0-23 The hour of the day that the command
sequence executes
day 1-31 The day of the month that the command
sequence executes
month 1-12 The month of the year that the command
sequence executes
weekday 0-6 The day of the week that the command
sequence executes. Sunday=0, Monday = 1, Tuesday = 2, and so forth.
command Special The complete sequence of commands to be executed. The
command string must conform to Bourne shell syntax. Commands,
executables (such as scripts), or combinations are acceptable.
Related
Can someone help mw with the cron expression for running job on 1st weekday??
Is it possible in simple unix crontab?
If your week start on Monday and you want to run script every monday you should use something like (suppose you run your script at 22h 00m)
0 22 * * 1 /path/to/script
If you want to run the script first work day of month and your week start on Monday you can try something like:
0 22 1,2,3,4,5,6,7 * * /path/to/script
and add on the begin of the script this:
if [ "$(date +%u) -ne 1 ]
then exit
fi
this will end the script if you run it on day of week which is not Monday
I am trying to run a crontab with the expression given below. But i am getting bad day-of-month error.
My requirement is to run this code:
everyday except Sunday
every hour starting 2 am till 10pm
0 2-22 ? * 0-6 * /usr/bin/python /my/location/to/python_code_for_cron/sampletest.py
Is there some issue with the cron expression or something else that i need to install?
FYI: I am using crontab -e to edit my crontab
You just have too many arguments in there. Read man -s5 crontab for more info. The fields are:
minute hour day-of-month month day-of-week
Also, 0-6 is the same as * for day-of-week. Your line should read:
0 2-22 * * 1-6 /usr/bin/python /my/location/to/python_code_for_cron/sampletest.py
just to verify my understanding of cron-syntax, the following expression will fire on a saturday at 02:42 in the middle of the month, right?
42 02 12-19 * 6 myScript > /dev/null 2>&1
cheers
Nicolaie
The script myScript (not good without a path here!) will be executed at 2:42 indeed, on every day between and including the 12th to the 19th of each month that is a saturday.
Actually
42 02 12-19 * 6 myScript > /dev/null 2>&1
means run on 12 thru 19 and every Saturday.
You need a more complex line to do what you state:
0 4 8-14 * * test $(date +\%u) -eq 6 && echo "2nd Saturday"
is an example from the manfile on my system. It uses a trivial execution after making sure it is Saturday.
See http://www.adminschoice.com/crontab-quick-reference/ as well as > man 5 crontab (at the commandline) for more.
How to configure a cron job to run every night at 2:30? I know how to make it run at 2, but not 2:30.
crontab -e
add:
30 2 * * * /your/command
To edit:
crontab -e
Add this command line:
30 2 * * * /your/command
Crontab Format:
MIN HOUR DOM MON DOW CMD
Format Meanings and Allowed Value:
MIN Minute field 0 to 59
HOUR Hour field 0 to 23
DOM Day of Month 1-31
MON Month field 1-12
DOW Day Of Week 0-6
CMD Command Any command to be executed.
Restart cron with latest data:
service crond restart
As seen in the other answers, the syntax to use is:
30 2 * * * /your/command
# ^ ^
# | hour
# minute
Following the crontab standard format:
+---------------- minute (0 - 59)
| +------------- hour (0 - 23)
| | +---------- day of month (1 - 31)
| | | +------- month (1 - 12)
| | | | +---- day of week (0 - 6) (Sunday=0 or 7)
| | | | |
* * * * * command to be executed
It is also useful to use crontab.guru to check crontab expressions.
The expressions are added into crontab using crontab -e. Once you are done, save and exit (if you are using vi, typing :x does it). The good think of using this tool is that if you write an invalid command you are likely to get a message prompt on the form:
$ crontab -e
crontab: installing new crontab
"/tmp/crontab.tNt1NL/crontab":7: bad minute
errors in crontab file, can't install.
Do you want to retry the same edit? (y/n)
If you have further problems with crontab not running you can check Debugging crontab or Why is crontab not executing my PHP script?.
An easy way to write cron is to use the online cron generator
It will generate the line for you. One thing to note is that if you wish to run it each day (not just weekdays) you need to highlight all the days.
As an addition to the all above mentioned great answers, check the https://crontab.guru/ - a useful online resource for checking your crontab syntax.
What you get is human readable representation of what you have specified.
See the examples below:
30 2 * * * (answer of this question)
#daily
59 23 31 12 *
30 2 * * * wget https://www.yoursite.com/your_function_name
The first part is for setting cron job and the next part to call your function.
30 2 * * * Every Day at 2:30 Am
30-31 2 * * * Every Day at 2:30 -31 am
Along with he answers its important to understand the cron expressions , i face a lot of difficulty in understanding .
But an intuitive way to understand is given here .
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 ?
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.)
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
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.