Trying to understand filter syntax

[Antony Stone]

Hi.

I've just discovered and started to use arbtt.

I've been collecting stats for a few days now, and I'm trying to create some 
filtering rules for my type of activity, so I can get some useful reports out 
of it.

I've read https://arbtt.nomeata.de/doc/users_guide/configuration.html and 
https://arbtt.nomeata.de/doc/users_guide/effective-use.html (in fact I've read 
all of https://arbtt.nomeata.de/doc/users_guide/index.html )

However, something escapes me about the syntax used.


For example, I can do:

	$ arbtt-stats -f '$sampleage < 24:00'

and it shows me an analysis for the past 24 hours.

However, I'd like to do an analysis for yesterday, not the 24 hours up to this 
moment right now, so I'm trying to express that.

If I try:

	$ arbtt-stats -f '$date >= 2017-07-01 && $date < 2017-07-02'

it tells me:

arbtt-stats: "commad line parameter" (line 1, column 14):
unexpected "-"
expecting digit, "=~", ">=", ">", "==", "=", "<" or "<="
Cannot compare expressions of type Date and type Integer


So, 2017 is clearly being interpreted as an integer, and then the - sign 
confuses the parser.

So, let's try it as a string:

	$ arbtt-stats -f '$date >= "2017-07-01" && $date < "2017-07-02"'

arbtt-stats: "commad line parameter" (line 1, column 23):
unexpected "&"
expecting "=~", ">=", ">", "==", "=", "<" or "<="
Cannot compare expressions of type Date and type String

So, I can't compare a Date with an Integer, and I can't compare a Date with a 
String - what *can* I compare a Date with?

I'm looking at the example given in the documentation, about ¾ of the way down 
https://arbtt.nomeata.de/doc/users_guide/configuration.html ):

	$date >= 2001-01-01 && $date <= 2001-01-02


and I can't see what's different about my version for this year...


Can someone please explain how I can create a filter which evaluates to "the 24 
hours of yesterday"?


Thanks,


Antony.

-- 
"Can you keep a secret?"
"Well, I shouldn't really tell you this, but... no."


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