Filters can be set for spots, announcements and WWV. You will find the directories for these under /spider/filter. You will -find some examples in the directories with the suffix .issue. There are two types of filter, one for incoming -information and one for outgoing information. Outgoing filters are in the form CALLSIGN.pl and incoming filters -are in the form in_CALLSIGN.pl. Filters can be set for both nodes and users. -
-
All filters work in basically the same way. There are several elements delimited by commas. -There can be many lines in the filter and they are read from the top by the program. -When writing a filter you need to think carefully about just what you want to achieve. You -are either going to write a filter to accept or to reject. -Think of a filter as having 2 main elements. For a reject filter, you would have a line -or multiple lines rejecting the things you do not wish to receive and then a default -line accepting everything else that is not included in the filter. Likewise, for an -accept filter, you would have a line or multiple lines accepting the things you wish -to receive and a default line rejecting everthing else. +
Filters can be set for spots, announcements and WWV. You will find the +directories for these under /spider/filter. You will find some examples in +the directories with the suffix .issue. There are two types of +filter, one for incoming information and one for outgoing information. +Outgoing filters are in the form CALLSIGN.pl and incoming filters +are in the form in_CALLSIGN.pl. Filters can be set for both nodes +and users. +
+
All filters work in basically the same way. There are several elements +delimited by commas. There can be many lines in the filter and they are +read from the top by the program. When writing a filter you need to think +carefully about just what you want to achieve. You are either going to write +a filter to accept or to reject. Think of a filter as +having 2 main elements. For a reject filter, you would have a line or multiple +lines rejecting the things you do not wish to receive and then a default line +accepting everything else that is not included in the filter. Likewise, for an +accept filter, you would have a line or multiple lines accepting the things you +wish to receive and a default line rejecting everthing else.
In the example below, a user requires a filter that would only return SSB spots -posted in Europe on the HF bands. This is achieved by first rejecting the CW section -of each HF band and rejecting all of VHF, UHF etc based on frequency. +posted in Europe on the HF bands. This is achieved by first rejecting the CW +section of each HF band and rejecting all of VHF, UHF etc based on frequency. Secondly, a filter rule is set based on CQ zones to only accept spots posted in Europe. Lastly, a default filter rule is set to reject anything outside the filter.
@@ -56,7 +60,8 @@ $in = [
-
The actual elements of each filter are described more fully in the following sections. +
The actual elements of each filter are described more fully in the following +sections.
-
There are 3 elements here to look at. Firstly, the action element. This is very simple and only 2 possible states exist, -accept (1) or drop (0). +
There are 3 elements here to look at. Firstly, the action element. This is +very simple and only 2 possible states exist, accept (1) or drop (0).
-
The second element is the field_no. There are 13 possiblities to choose from here .... +
The second element is the field_no. There are 13 possiblities to choose from +here ....
@@ -92,23 +98,27 @@ accept (1) or drop (0).
-
The third element tells us what to expect in the fourth element. There are 4 possibilities .... +
The third element tells us what to expect in the fourth element. There are +4 possibilities ....
n - numeric list of numbers e.g. [ 1,2,3 ]
- r - ranges of pairs of numbers e.g. between 2 and 4 or 10 to 17 - [ 2,4, 10,17 ]
+ r - ranges of pairs of numbers e.g. between 2 and 4 or 10 to 17 - [ 2,4, 10,17 ]
a - an alphanumeric regex
d - the default rule
-
The fifth element is simply the hops to set in this filter. This would only be used if the filter was for a node of -course and overrides the hop count in hop_table.pl. +
The fifth element is simply the hops to set in this filter. This would only +be used if the filter was for a node of course and overrides the hop count in +hop_table.pl.
-
So, let's look at an example spot filter. It does not matter in the example who the filter is to be used for. -So, what do we need in the filter? We need to filter the spots the user/node requires and also set a default rule for -anything else outside the filter. Below is a simple filter that stops spots arriving from outside Europe. +
So, let's look at an example spot filter. It does not matter in the example +who the filter is to be used for. So, what do we need in the filter? We need +to filter the spots the user/node requires and also set a default rule for +anything else outside the filter. Below is a simple filter that stops spots +arriving from outside Europe.
@@ -119,18 +129,25 @@ $in = [
-
So the filter is wrapped in between a pair of square brackets. This tells Spider to look in between these limits. -Then each line is contained within its own square brackets and ends with a comma. Lets look carefully at the first line. -The first element is 0 (drop). Therefore anything we put on this line will not be accepted. The next element is 4. -This means we are filtering by the spotter. The third element is the letter "a" which tells the program to expect an -alphanumeric expression in the fourth element. The fourth element is a list of letters separated by the pipe symbol. +
So the filter is wrapped in between a pair of square brackets. This tells +Spider to look in between these limits. Then each line is contained within +its own square brackets and ends with a comma. Lets look carefully at the first +line. The first element is 0 (drop). Therefore anything we put on this line +will not be accepted. The next element is 4. This means we are filtering by +the spotter. The third element is the letter "a" which tells the program to +expect an alphanumeric expression in the fourth element. The fourth element +is a list of letters separated by the pipe symbol.
-
What this line does is tell the program to drop any spots posted by anyone in the USA, Canada or Japan. +
What this line does is tell the program to drop any spots posted by anyone in +the USA, Canada or Japan.
-
The second line is the default rule for anything else. The "d" tells us this and the line simply reads... accept anything else. +
The second line is the default rule for anything else. The "d" tells us this +and the line simply reads... accept anything else.
-
You can add as many lines as you need to complete the filter but if there are several lines of the same type it is neater -to enclose them all as one line. An example of this is where specific bands are set. We could write this like this .... +
You can add as many lines as you need to complete the filter but if there are +several lines of the same type it is neater to enclose them all as one line. +An example of this is where specific bands are set. We could write this like +this ....
@@ -180,10 +197,11 @@ $in = [
];
In this example, only the prefixes listed will be allowed. It is possible to be quite specific. The Dutch prefix "P" is -followed by several secondary identifiers which are allowed. So, in the example, "PA" or "PE" would be ok but not "PG". It -is even possible to allow information from a single callsign. In the example this is DK0WCY, to allow the posting of his -Aurora Beacon. +
In this example, only the prefixes listed will be allowed. It is possible to +be quite specific. The Dutch prefix "P" is followed by several secondary +identifiers which are allowed. So, in the example, "PA" or "PE" would be ok +but not "PG". It is even possible to allow information from a single callsign. +In the example this is DK0WCY, to allow the posting of his Aurora Beacon.
-
It should be noted that the filter will start to be used only once a user/node has logged out and back in again. -
I am not going to spend any more time on these filters now as they will become more "comprehensive" in the near future. +
It should be noted that the filter will start to be used only once a user/node +has logged out and back in again. +
I am not going to spend any more time on these filters now as they will become +more "comprehensive" in the near future.