Patrick Welche wrote:
Quoting the fine crontab(5) manual:
Note: The day of a command's execution can be specified by two fields
-- day of month, and day of week. If both fields are restricted (ie,
aren't *), the command will be run when either field matches the cur-
rent time. For example,
``30 4 1,15 * 5'' would cause a command to be run at 4:30 am on the 1st
and 15th of each month, plus every Friday.
How can you run a command when _both_ fields match?
Don't know, but obviously there coult be a need for it.
If the rule were _both_ and I wanted _either_, I could write 2 lines in crontab. The opposite isn't obvious to me. A use case for _both_ would be "run this backup every Friday unless it's the first of the month (because the different monthly backup is running)" - and I can't believe I'm the first one to encounter this ;-)
Replacing that with two lines is not equivalent. If both match, you would then get the command run twice, which might not be what was wanted either.
Obviously if you could express both variants, that would be best.As it is now, I guess the easiest way is having a script run by the command, which checks of the other condition also is met, and if not, just finish.
Johnny