Run crontab Every 10 Minutes
by Vivek Gite · 3 comments
Q. How do I run a cron job or a shell script every 10 minutes using Linux / UNIX cron service?
A. cron is a time-based scheduling service in Linux / Unix-like computer operating systems.
Login to UNIX system
Type the following command to enter cronjob:
$ crontab -e
Each cronjob has following syntax:
# +---------------- 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
To get crontab to run a task every 10 minutes you could type as follow
*/10 * * * * /path/to/command
Save and close the file.
credits to cyberciti.biz
Subscribe to:
Post Comments (Atom)
Examples
ReplyDeleteHow do I run a task every 5 minutes?
One option is to use
MAILTO=cron@username.plus.com
0,5,10,15,20,25,30,35,40,45,50,55 * * * * /command/to/execute
However, there is a special shortcut for this:
MAILTO=cron@username.plus.com
*/5 * * * * /command/to/execute
The */5 is known as a short form equivalent to 0,5,10,15,20 etc... and achieves the same effect as the previous example, executing the command every 5 minutes. Other examples are: */2 would be every 2 mins, */30 every 30 minutes and so on. You can use the same short form for the hour indicator */2 every 2 hours, */6 every 6 hours etc.
How do I run a task at 6PM every night?
MAILTO=cron@username.plus.com
00 18 * * * /command/to/execute
How do I run a php script at 2am every Sunday?
MAILTO=cron@username.plus.com
00 02 * * sun /usr/local/bin/php $HOME/php/script.php
Notice that the php command is specified using an absolute path because cron will not be able to find it otherwise. If it was not specified, the script.php will fail to execute and an error like: php not found will be reported in the email you receive or in Mailbox. You may not spot this, especially if you run it successfully from the $ prompt as php /absolute/path/to/script.php or even php script.php if it is in the current directory. Also note $HOME is being used instead of /files/homeX/username/
Example MailBox or Email from cron
tutorialsteam@shell2 tutorialsteam $ more Mailbox
From root@shell1.cgi.plus.net Sun Feb 01 23:11:27 2004
Return-Path:
Delivered-To: tutorialsteam@shell1.cgi.plus.net
Received: (qmail 18527 invoked by uid 10667); 1 Feb 2004 23:11:25 -0000
Date: 1 Feb 2004 23:11:25 -0000
Message-ID: <20040201231125.18514.qmail@shell1.cgi.plus.net>
From: root@shell1.cgi.plus.net (Cron Daemon)
To: tutorialsteam@shell1.cgi.plus.net
Subject: Cron $HOME/me
X-Cron-Env:
X-Cron-Env:
X-Cron-Env:
X-Cron-Env:
I am:
uid=10667(tutorialsteam) gid=500(shellcgi) groups=500(shellcgi)
PATH is set to:
/usr/bin:/bin
Crontab command options
crontab -e
As explained earlier, this will allow you to edit the contents of your crontab file or create a new crontab file if one does not already exist. The editor used is called vi or vim.
crontab -l
This will list the current contents of your crontab file and is very useful for checking you have edited it correctly after crontab -e. It is often useful to make a copy of the crontab file in case you make a mistake with an edit.
$ crontab -l >mycrontab
This will create a local copy of the crontab file called mycrontab.
crontab -r
Use with caution: This will delete the contents of your current crontab file (another reason for making a local copy!)
crontab file
This is an alternative method for setting up your crontab file. Instead of using crontab -e, you can create a file containing the cron commands and use that to replace or overwrite the current contents of your crontab file. Note replace - it will overwrite anything that is currently in your crontab file with the contents of file.