如果cronjob备份失败，则执行curl命令

Question

I have a cronjob that takes backup of my DB every 10 min. I want to receive an SMS whenever the backup fails.

Example:

*/1 * * * * sudo /usr/local/sbin/mysql.sh 2>&1 | curl 'http:www.smsapi.com/user=username&pass=password&text=$errormsg'

Currently it's not sending any SMS. How can I append error message to curl? (I have also tried this for Email instead of SMS, but that too does not work).

Answer 1

Mail:

mysql.sh 2>&1 | mail -s "Mysql backup" -E user@host

cUrl:

mysql.sh 2>&1 | curl "http:www.smsapi.com/user=username&pass=password&text=`cat -`"

Please note: double quotes instead of apostrophes and backticks with a command to convert std input to a parameter. The conversion is rather primitive, it doesn't URL-quote special characters.

Answer 2

You need to use the double-pipe command || error-handler command || error-handler for the error-handler to be called only in case the command fails.

I suggest you reverse the logic command && success-handler and use a service such as WDT.io for the success-handler to alert you in case of a missing success (aka failure). The reason is that the cron job itself can fail to run which you'd never find out about when using an error-handler.

As for your second question, how to append the error, you can access the previous return code using $? .