Cron Email Error
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Cron Email On Error Only
with us Server Fault Questions Tags Users Badges Unanswered Ask Question _ Server Fault is a question cron error mail and answer site for system and network administrators. Join them; it only takes a minute: Sign up Here's how it works: Anybody can ask a question cron error failed to open pam security session success Anybody can answer The best answers are voted up and rise to the top Cron: Only get errors in emails? up vote 22 down vote favorite 5 I finally set up a realistic backup schedule on my data through a shell script,
Cron Error Bad Minute
which are handled by cron on tight intervals. Unfortunately, I keep getting empty emails each time the CRON has been executed and not only when things go wrong. Is it possible to only make CRON send emails when something goes wrong, ie. my TAR doesn't execute as intended? Here's how my crontab is setup for the moment; 0 */2 * * * /bin/backup.sh 2>&1 | mail -s "Backup status" email@example.com Thanks a lot! bash shell cron schedule share|improve this question asked Jan 24 '11
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at 9:40 Industrial 53921535 add a comment| 4 Answers 4 active oldest votes up vote 32 down vote accepted Ideally you'd want your backup script to output nothing if everything goes as expected and only produce output when something goes wrong. Then use the MAILTO environment variable to send any output generated by your script to your email address. MAILTO=email@example.com 0 */2 * * * /bin/backup.sh If your script normally produces output but you don't care about it in cron, just sent it to /dev/null and it'll email you only when something is written to stderr. MAILTO=email@example.com 0 */2 * * * /bin/backup.sh > /dev/null share|improve this answer answered Jan 24 '11 at 9:53 Cakemox 13.1k52957 add a comment| up vote 8 down vote Using cronic wrapper script looks like a good idea; to use it you don't have to change your scripts. Instead of: 0 1 * * * backup >/dev/null 2>&1 do: 0 1 * * * cronic backup More info on http://habilis.net/cronic/. share|improve this answer edited Sep 8 at 11:39 Law29 2,3731319 answered Feb 13 '12 at 21:43 Ricardo Pardini 41638 I really don't see how that will help when the problem is nothing more than an incorrect cron line and cron is doing exactly what it is told to do. –John Gardeniers Feb 14 '12 at 0:17 @JohnGardeniers it helps because sometimes you have output without an error. –Mikhail Aug 31 '14 at 19:59 2 Alternatively, chronic from the moreutils package: joeyh.name/code/moreutils &ndash
annoying feature of cron: unwanted emailed output, or "cram" (cron spam). If the Unix Haters list was still active, I would submit cron error cannot set security context the rant below to gain membership. (feedback to: chuck@habilis.net) The Disease One of
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the best features of cron is its automatic email - it is also its worst feature. Cron automatically emails the cron error bad username output of a cron job to the user. On the face of it, this sounds like a great idea. Cron jobs can run automatically in the background for months at a time - http://serverfault.com/questions/226074/cron-only-get-errors-in-emails so getting an email when a problem occurs sounds useful. Unfortunately, cron's idea of "output" is simultaneously too broad and too narrow to actually be useful. Cron considers any output to be significant - including standard output. This interacts badly with many unix commands, which often send status info to standard out. Some commands have a quiet options, but that can turn off all error output http://habilis.net/cronic/ too. To make matters worse, cron ignores command result codes, meaning that errors from quiet programs are ignored. It is almost impossible to create a non-trivial cron job that is quiet enough to run without output, but still reports all errors. Following the principle of "Worse is Better", the typical solution is to sweep it all under the carpet by redirecting all output to /dev/null, and hoping for the best: 0 1 * * * backup >/dev/null 2>&1 Now when your cron job fails, you will never know about it. Using cron to backup your files? Sorry, the cron job has been failing due to permission errors for months - all your files are gone. Could cron be fixed? Although almost all current implementation of cron are open source, cron's pathological behavior has been petrified into the Unix standards. So if it isn't broken, it isn't cron. The only solution left is a work-around. The Cure: Cronic Download: cronic v3 Cronic is a small shim shell script for wrapping cron jobs so that cron only sends email when an error has occurred. Cronic defines an error as any non-trace error output or a non-zero result code. C
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring http://unix.stackexchange.com/questions/207/where-are-cron-errors-logged developers or posting ads with us Unix & Linux Questions Tags Users Badges Unanswered Ask Question _ Unix & Linux Stack Exchange is a question and answer site for users of Linux, FreeBSD and other Un*x-like operating systems. Join them; http://www.cyberciti.biz/faq/disable-the-mail-alert-by-crontab-command/ it only takes a minute: Sign up Here's how it works: Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top Where are cron errors logged? up vote 71 down vote on error favorite 11 If I setup cron jobs incorrectly they appear to silently fail. Where should I look for an error log to understand what went wrong? cron scheduling logs share|improve this question edited May 4 '13 at 20:26 Anthon 47.4k1462125 asked Aug 11 '10 at 2:19 Brian Lyttle 511169 add a comment| 8 Answers 8 active oldest votes up vote 62 down vote As others have pointed out, cron will email you the output of any program it runs (if there cron error bad is any output). So, if you don't get any output, there are basically three possibilities: crond could not even start a shell for running the program or sending email crond had troubles mailing the output, or the mail was lost. the program did not produce any output (including error messages) Case 1. is very unlikely, but something should have been written in the cron logs. Cron has an own reserved syslog facility, so you should have a look into /etc/syslog.conf (or the equivalent file in your distro) to see where messages of facility cron are sent. Popular destinations include /var/log/cron, /var/log/messages and /var/log/syslog. In case 2., you should inspect the mailer daemon logs: messages from the Cron daemon usually appear as from root@yourhost. You can use a MAILTO=... line in the crontab file to have cron send email to a specific address, which should make it easier to grep the mailer daemon logs. For instance: MAILTO=my.offsite.email@example.org 00 15 * * * echo "Just testing if crond sends email" In case 3., you can test if the program was actually run by appending another command whose effect you can easily check: for instance, 00 15 * * * /a/command; touch /tmp/a_command_has_run so you can check if crond has actually run something by looking at the mtime of /tmp/a_command_has_run. share|improve this answer edited Aug 12 '10 at 11:42 answered Aug 11 '10 at 20:27 Riccardo Murri 9,2712931 1 Case 3: The scrip
17, 2015 in CentOS, Debian / Ubuntu, FreeBSD, Linux, RedHat and Friends, Suse, UNIXHow do I to disable the mail alert send by crontab? When my job is executed and the jobs cannot run normally it will sent an email to root. Why do I receive e-mails to my root account from cron? How can I prevent this? How can I disable email alert sent by cron jobs on a Linux or Unix-like systems? The crontab command is used to maintain crontab files for individual users. By default the output of a command or a script (if any produced), will be email to your local email account. To stop receiving email output from crontab you need to append following strings at the end of crontab entry.
Cron job prevent the sending of errors and outputTo prevent the sending of errors and output, add any one of the following at the end of the line for each cron job to redirect output to /dev/null.>/dev/null 2>&1.OR> /dev/nullOR> /dev/null 2>&1 || trueCron job exampleEdit/Open your cron jobs, enter: $ crontab -e Append string >/dev/null 2>&1 to stop mail alert:0 1 5 10 * /path/to/script.sh >/dev/null 2>&1OR0 1 5 10 * /path/to/script.sh > /dev/nullOR0 * * * * /path/to/command arg1 > /dev/null 2>&1 || trueSave and close the file.Set MAILTO variableYou can set MAILTO="" variable at the start of your crontab file. This will also disable email alert. Edit/Open your cron jobs: $ crontab -e At the top of the file, enter: MAILTO="" Save and close the file. Share this tutorial on:TwitterFacebookGoogle+Download PDF version Found an error/typo on this page?This entry is 8 of 14 in the Linux Cron Jobs Howto & Tutorial series. Keep reading the rest of the series:What is cron on a Linux or Unix-like systems?HowTo: Add Jobs To cron Under Linux or UNIX?Linux Verify crond Daemon And Cronjobs Are RunningLinux Start Restart and Stop The Cron or Crond ServiceLinux: List / Display All Cron JobsLinux / UNIX Crontab File LocationLinux / UNIX: Change Crontab Email Settings ( MAILTO )Disable The Mail Alert By Crontab Command On a Linux or Unix-like SystemsLinux: At What Time Cron Entries In cron.daily, cron.weekly, cron.monthly Run?Linux Execute Cron Job After System RebootLinux / UNIX Setup and Run PHP Script As A Cron JobHow to run