Table of Contents
SavaPage background jobs are scheduled with Cron Trigger Format expressions.
Cron Trigger Format is similar to GNU/Linux cron scheduling
expressions. An extensive tutorial can be found here, and a simplified introduction is presented in this section.
A Cron Trigger is an expression comprised of 6 mandatory fields separated by white space.
| Field Name | Range | Special | Remark |
|---|---|---|---|
|
Seconds |
| , - * |
Not relevant in our case: can be zero. |
|
Minutes | 0-59 | , - * | |
|
Hours | 0-23 | , - * | |
|
Day of month | 1-31 | , - * ? | |
|
Month | 1-12 | , - * |
Range is identical to |
|
Day of week | 1-7 | , - * ? |
Range is identical to Note: GNU/Linux |
Table O.1. Cron Trigger Format - simplified
Special character values are:
, : used to
specify additional values. For
example, “2,4,6” in the day-of-week field means the days
Monday, Wednesday, and Friday.
- : used to
specify ranges. For example, “2-6” in
the day-of-week field means the days Monday to Friday.
* : used to select
all values within a field. For
example: * in the Hours field means “every
hour”.
? : used to select
no specific value. This is useful
when you need to specify something in one of the two fields in which the
character is allowed, but not the other. For example, if I want a
trigger to fire on a particular day of the week (say, Sunday), but don’t
care what day of the month that happens to be, you would put
1 in the day-of-week field, and
? in the day-of-month field.