I'm assuming you are refering to the "Match on every run" option on the Advanced tab of the Watcher Rule. I'm having a tough time getting this to work as I would hope it would.
The problem I'm running into is that I have the Profile set to mode "full_time". So, I only want the watcher rules evaluated when the timestamp on the file changes. The problem I'm seeing is that when I have the "Match on every run" option checked, even if the file has not been changed, I still automatically get the alarm on no match at the check interval. This seems quite silly.
I don't know if I'm using it incorrectly or what, but it seems to me that when I select that option, it will literally send an alarm everytime there is a check interval regardless of what I have for a match expression. (even if the phase I'm searching for actually exists in the file) or even if the file itself was updated.
Sounds like the "Match on every run" does exactly that. Just matches regardless.
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UPDATE
So, I did some more testing with this, and it is not that it is sending the "Match on every run" EVERY time, but if the setting is "full_time" or something that is looking for the contents or timestamp on the file to change in order to evaluate, it will send the alarm on no match if it does not evaluate the file (so, it doesn't see the expected match expression). Maybe there is a good reason for this behavior, but this doesn't seem to be especially helpful to me...
Karen