cron job

working2hard · 07-28-2004, 05:34 PM

i know this might have been asked but can someone help me with this

I want my .jar to be run every monday and friday I am trying to add it to a cron job or something like that anyone have any ideas?

I was guessing something like 0 3 java -jar myFile.jar

I am not sure where to add it and the exact syntax and how stuff works

HELP PLS!

working2hard

:Pengy

SheldonPlankton · 07-28-2004, 06:05 PM

do a ...

Code:

$ man 5 crontab

that's where I got this info ...

The time and date fields are:

field allowed values
----- --------------
minute 0-59
hour 0-23
day of month 1-31
month 1-12 (or names, see below)
day of week 0-7 (0 or 7 is Sun, or use names)

... so you should execute this command (I hope you know how to use vi)

Code:

$ crontab -e

That will bring up a text editor (vi probably). Depends on what your EDITOR env var. is set to. Anyways enter this ...

Code:

* * * * 0,3 java -jar myFile.jar

To verify that you saved your changes do this ...

Code:

$ crontab -l

working2hard · 07-28-2004, 06:11 PM

crontab -e is that a new file or do I have to go into /etc/ and pull up the cron file?

I understand the rest of the suggestion and thanks a lot for that. I just don't know where to type in the command

osvaldomarques · 07-28-2004, 06:30 PM

crontab is a wrapper for you to edit your crond files. I suggest you to not play with the files in the /etc because they are system files.
Each user, even root, can have a separated cron file, in the directory "/var/spool/cron". The command "crontab -e" copy this file to a temporary area, calls your preferred editor to edit it, then, when you save your editions, it checks the proper syntax before submit it to the crond.

working2hard · 07-28-2004, 06:39 PM

thanks for that clarification

another question

should my command have 3 asterics or 4 cos I am thinking each asteric stands for a field and there are 5 feilds so something like

***0,3 java -jar Myfile.jar

thanks for all the help

SheldonPlankton · 07-28-2004, 08:49 PM

osvaldomarques · 07-28-2004, 09:12 PM

You're right in your standing. You need to have one asterisk for each "don't care" field but you have to put a space between each field.