cronjobber: cron job wrapper

Sources and Installation
Job Setup
checker API
Man Page
Theory of Operation

checker API

You can configure cronjobber to invoke a user-provided script to look at job output and decide whether or not to have mail sent. If no script is provided, mail will be sent if the job exited non-zero or if the job produced any output on stdout or stderr.

The name of the checker script is given to cronjobber using the -x command line flag. It is invoked directly, unlike the job which is invoked via $SHELL -c.

Current Directory

When the script is started, its current directory will be the cronjobber state directory, which is passed to conjobber with the -s flag.


The checker script is passed the same minimal environment given to the job. One of the following variables will also be set:

WEXITSTATUS If the job exited normally, this variable will hold its exit status.
WTERMSIG If the job was killed by a signal, this variable will hold the number of the signal.
WSTATUS Shouldn't happen.


The checker script stdin will be the log file produced by the job just run. The checker script may read from stdin and/or directly read log, whichever makes more sense.


stdout and stderr are unchanged from those provided by cron(8). Anything output from the checker will result in cron sending mail to the crontab owner.

command line arguments

No command line arguments are passed to the checker in the current version of cronjobber.

Exit Values

The checker should exit 0 or 1. 0 means the job succeeded and mail should not be sent. 1 means the job failed in some way so mail should be sent.