Blank lines and lines beginning with # in these files are ignored. Entries are lines with fields
minute hour day month weekday host commandCommand is a string, which may contain spaces, that is passed to an rc (1) running on host for execution. The first five fields are integer patterns for
0
\w'month of year 'u minute 0-59
hour 0-23
day of month 1-31
month of year 1-12
day of week 0-6; 0=Sunday
The syntax for these patterns is
.EX time : '*' | range range : number | number '-' number | range ',' rangeEach number must be in the appropriate range. Hyphens specify inclusive ranges of valid times; commas specify lists of valid time ranges.
To run the job, cron calls host and authenticates remote execution, equivalent to running rx host command (see con (1)). The user's profile is run with $service set to rx . If host is set to local , cron will run the command as user on the local machine without using rx .
Cron is not a reliable service. It skips commands if it cannot reach host within two minutes, or if the cron daemon is not running at the appropriate time.
/cron/lock lock file to prevent multiple cron s running