For this to work, you need to have mail working properly. A common arrangement is to redirect output to a file, in which case of course the cron daemon won't see the job return any output. A variant is to redirect standard output to a file or write the script so it never prints anything - perhaps it stores results in a database instead, or performs maintenance tasks which simply don't output anything? But I don't particularly endorse this practice.
It mainly makes sense if you don't really expect anything on standard output, but may have overlooked something, perhaps coming from an external tool which is called from your script. If you want to write outside of your home directory, you obviously need to separately make sure you have write access to that destination file. From within your script, make sure to keep regular output actual results, ideally in machine-readable form and diagnostics usually formatted for a human reader separate.
In a shell script,. Some platforms and e. Notice also how error messages should include the name of the script which produced the diagnostic message. If you'd still like to check your cron jobs you should provide a valid email account when setting the Cron jobs in cPanel.
When you specify a valid email you will receive the output of the cron job that is executed. Thus you will be able to check it and make sure everything has been executed correctly.
Note that you will not receive an email if there is no output from the cron job command. Please bear in mind that you will receive an email for each of the executed cron jobs. This may flood your inbox in case your crons run too often. Stack Overflow for Teams — Collaborate and share knowledge with a private group.
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Asked 10 years, 9 months ago. Active 15 days ago. Viewed k times. Improve this question. Adrian M. Take a look at this post: Managing log files created by cron jobs. Add a comment. Active Oldest Votes. Improve this answer. Spliffster Spliffster 6, 2 2 gold badges 22 22 silver badges 17 17 bronze badges.
If I setup cron jobs incorrectly they appear to silently fail. Where should I look for an error log to understand what went wrong? As others have pointed out, cron will email you the output of any program it runs if there is any output. So, if you don't get any output, there are basically three possibilities:. Case 1. In case 2. For instance:. In case 3. Keep in mind that this will supercede the mail behaviour that has been mentioned before, because crond iself won't receive any output from the job.
If you want to keep that behaviour you should look into tee 1. If you aren't seeing the mails, you might be spamming root yourcompany with the errors which can be quite annoying to the people who use that account for monitoring. Try sending the output to Syslog instead:. This works great for errors messages which are only lines long, such as "yourcronjob: command not found".
It also makes use of your existing syslog infrastructure Logrotation, central syslogging, Splunk, etc. It also reduces email spam to root. You should get email from crond when the job either fails to run or when the job returns a nonzero exit code. Try typing:. It is very primitive by modern standards, but you can pretty much count on it to always be available. Other, better mail agents may be available, but there are enough of them that you never know which one is installed on some random machine you happen to be using.
Note that unless you have configured your system as an Internet email server, this mail subsystem is used only within the machine. You can send email to and receive from other users on the machine, but you may not be able to send email out to the world, and email from the outer world certainly won't be able to come to your machine. The default cron configuration will send you a mail with the output of your program. If this fails, you could try wrapping your failing program in a shell script that ensures that the program does not fail, and you could further log the output.
I stumbled across this thread a few years ago experiencing the same problems and just recently came across a solution to the above mentioned cases by Ricardo. The lack of an email is hard to detect as you mentioned and you certainly don't want to spam your root yourcompany email.
If interested check out deadmanssnitch. This tool seems to solve the aforementioned cases. Seems pretty simple to use— just add the bit of code the tool gives you to your cronjob. If your job fails to run at a specified internal, you will be alerted. If you job starts running again you'll also be alerted.
It does not show you items that are set in your crontab. I use vixie-cron , so I don't know if this applies to everything. But I have a dead. Edit I just Google'd dead. It has nothing to do with cron apparently. What has happened. My cron jobs could no longer run and crontab -l can no list any of my cron jobs.
I recommend you check the logs as indicated in this guide to determine why the cronjob is not running as expected. I also recommend you check what user you are using for SSH and what user is running the cronjobs to figure out why crontab is not displaying anything. I do apologize, however, I am not able to determine why your cronjob is not working, with the details you have provided. If you have a mailto line setup within your crontab then you should get emails from any failing cron jobs.
Get web hosting from a company that is here to help. Sign up today! Community Blog. Arnel Custodio Content Writer I. Do we have to put a reference to the cron job in the php file and if how? Hello Simon, You should not have to, is the code above not working for you? Best Regards, TJ Edens. I suggest going into the server to check if the testcron. Thanks, Praveen Kumar verma.
Hello Hrynkiw, Thank you for catching that, I have fixed the typo. Hello Kenny, If you have a mailto line setup within your crontab then you should get emails from any failing cron jobs. Was this article helpful? Let us know! Cancel reply. Need More Help? Search our Help Articles. Search for:. Current Customers. Get Reliable Web Hosting.
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