5.3 Built-in Variables

A number of built-in variables control the interpretation of crontab entries and execution of commands. Each built-in variable has two name variants: setting the name prefixed with ‘_JOB_’ affects only the cron job definition that immediately follows (with optional variable assignments in between), whereas setting the name prefixed with ‘_MICRON_’ affects all commands that follow, until another assignment of the same variable (or its ‘_JOB_’ counterpart) is encountered or the end of file is reached. For example, the following fragment instructs micrond to log all output produced by the command run-periodic to syslog facility ‘daemon’ using the tag ‘hourly’. These two settings affect only this particular command:

_JOB_SYSLOG_FACILITY = daemon
_JOB_SYSLOG_TAG = hourly

15 * * * *  root  run-periodic

Built-in variables are described in detail in built-in variables.