Comments on: Crontab – Quick Reference http://adminschoice.com/crontab-quick-reference Unix adminstrators documents , tip and more Thu, 11 Mar 2010 14:45:43 -0800 http://wordpress.org/?v=2.8.6 hourly 1 By: ian carter http://adminschoice.com/crontab-quick-reference/comment-page-1#comment-646 ian carter Thu, 11 Mar 2010 14:45:43 +0000 http://adminschoice.com/wp28/?p=43#comment-646 just being introduced to unix and the crontab utility. cool stuff. my question is this,how do i exit a crontab file after i have made a new one and save everything i have just done? will ^c do it? pls help Edit by admin If you have set editor as vi, wq! Should save it. just being introduced to unix and the crontab utility. cool stuff. my question is this,how do i exit a crontab file after i have made a new one and save everything i have just done? will ^c do it?
pls help

Edit by admin
If you have set editor as vi, wq! Should save it.

]]> By: Phil Horder http://adminschoice.com/crontab-quick-reference/comment-page-1#comment-605 Phil Horder Tue, 23 Feb 2010 09:48:18 +0000 http://adminschoice.com/wp28/?p=43#comment-605 The day of month & day of week are ORed, which makes cron less flexible than it could be. I need to run a job on the 3rd Wednesday of every month, but cron won't let me do this. I figured it out in the end; run every day in the 3rd week, but then check that the day is a Wednesday. e.g. 00 02 15-21 * * if [ `date +\%u` -eq 3 ] ; then run_myjob; fi Note that the \ is used to escape the %, otherwise cron treats it as a newline. The day of month & day of week are ORed, which makes cron less flexible than it could be. I need to run a job on the 3rd Wednesday of every month, but cron won’t let me do this. I figured it out in the end; run every day in the 3rd week, but then check that the day is a Wednesday. e.g.

00 02 15-21 * * if [ `date +\%u` -eq 3 ] ; then run_myjob; fi

Note that the \ is used to escape the %, otherwise cron treats it as a newline.

]]> By: Chuck WWW http://adminschoice.com/crontab-quick-reference/comment-page-1#comment-462 Chuck WWW Fri, 22 Jan 2010 21:00:53 +0000 http://adminschoice.com/wp28/?p=43#comment-462 Hey Farook, I had the same problem I think! Not sure if you found a solution, but I'm guessing *maybe* you are using a wget command in your crontab? If that's the case, use wget -q in the command line. The "-q" flag means quiet, and it won't output anything like a pesky php.1 file. Regards, Chuck Hey Farook,

I had the same problem I think!

Not sure if you found a solution, but I’m guessing *maybe* you are using a wget command in your crontab? If that’s the case, use wget -q in the command line. The “-q” flag means quiet, and it won’t output anything like a pesky php.1 file.

Regards,

Chuck

]]> By: martin http://adminschoice.com/crontab-quick-reference/comment-page-1#comment-186 martin Tue, 12 Jan 2010 18:11:31 +0000 http://adminschoice.com/wp28/?p=43#comment-186 A Note of caution for anybody setting up a crontab on a system that is NOT running 24/7: If there is an operation that is done once per day, make sure it is done when the system is expected to be on or bad things can occur. Years ago I worked on a SunOS system which was normally on only from 7am to 4pm (and properly shutdown at the end of the day) and rarely on outside that time period and the log file backup took place at 4AM on Sunday only. You can guess the result. A Note of caution for anybody setting up a crontab on a system that is NOT running 24/7:

If there is an operation that is done once per day, make sure it is done when the system is expected to be on or bad things can occur. Years ago I worked on a SunOS system which was normally on only from 7am to 4pm (and properly shutdown at the end of the day) and rarely on outside that time period and the log file backup took place at 4AM on Sunday only. You can guess the result.

]]> By: Farook http://adminschoice.com/crontab-quick-reference/comment-page-1#comment-50 Farook Fri, 08 Jan 2010 13:44:31 +0000 http://adminschoice.com/wp28/?p=43#comment-50 My Cron Script is working fine. And i used >/dev/null 2>&1 to Stop sending Emails. But each time a file is created in the same name of PHP file with trailing numbers like phpfile.php.1, phpfle.php.2, phpfile.php.3.... Is there any script to stop that? My Cron Script is working fine. And i used >/dev/null 2>&1 to Stop sending Emails. But each time a file is created in the same name of PHP file with trailing numbers like phpfile.php.1, phpfle.php.2, phpfile.php.3….
Is there any script to stop that?

]]> By: Boyd http://adminschoice.com/crontab-quick-reference/comment-page-1#comment-35 Boyd Thu, 07 Jan 2010 18:45:35 +0000 http://adminschoice.com/wp28/?p=43#comment-35 On the Mac OS X, the environmental variable TMP needs to be set to /private/tmp (I also set if for TEMP as well) to make crontab -e work. Apparently crontab -e needs to know where tmp is and not through the symbolic link /tmp. Otherwise, I would get an error message "crontab needs to be edited in place". Boyd On the Mac OS X, the environmental variable TMP needs to be set to /private/tmp (I also set if for TEMP as well) to make crontab -e work. Apparently crontab -e needs to know where tmp is and not through the symbolic link /tmp. Otherwise, I would get an error message “crontab needs to be edited in place”.

Boyd

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