[OZAPRS] Message Traffic and WX Alerts in Xastir

Andrew Errington a.errington at lancaster.ac.uk
Sat Nov 22 17:59:54 EST 2008

> Where I'm at. The sample file nwsc_ddmmyy.dbfawk contains exactly the
> same field sequence as c_aus20on08.dbf so I renamed it to
> c_aus20on08.dbfawk I did the same thing with z_aus20on08 and mz_aus13on08.
> The last two had extra fields which I removed as per
> readme.maps. I still have no polygons and I suspect it's due to errors in
> my dbfawk files.

If you start xastir in a console you'll see error messages printed if
xastir cannot find the .dbfawk file that goes with the shapefiles.  Also,
note that the .dbfawk files can go in one of two places, and their
location dictates how they are used.

I posted a link to Tom Russo's dbfawk howto already, but it seems to be
the same as your link to the dbfawk howto on the xastir wiki.

> There are two tools, dbfinfo and dbffields, in xastir but these have not
> compiled. Tom makes mention of compiling them separately, in the wiki. I've
> not had time yet to investigate this. Those tools enable one to compare a
> dbf file with a dbfawk file; guess I'll find out tomorrow :-)

dbffields is not a tool.  The tools are dbfinfo and testdbfawk.  It's not
strictly necessary to have these for this step as you can do one of three
things to get the list of files.

1) less *.dbfinfo
Just dump the file to the console and look for a bunch of names at the
beginning of the file.  You'll know them when you see them.

2) khexedit
Same deal, but a hex editor doesn't barf when you open a binary file

3) QGis (most useful)
Since we are using Linux we can easily get this rather nice GIS program,
which will recognise and import shapefiles.  Once you have imported the
shapefile you can look it its properties.
* Start QGIS
* Select Layer|Add a Vector Layer
* Open one of your .dbf files
* Marvel at how quickly xastir renders the same file
* In the layers list on the left, right-click on the layer you just
created and select Open Attributes.
* Across the top of the table is the list of field names in order (ignore
the 'id' field).  This list goes into the dbfinfo entry in the .dbfawk
file (it is the 'signature' that xastir uses to match the .dbfawk file to
a particular shapefile *if* the .dbfawk file is in the
/usr/local/share/xastir/config.  If the .dbfawk files is in the same
directory as the .dbf file it should have the same name.  For example
foo.dbf and foo.dbfawk)

dbffields is not a program.  The dbffields list in the .dbfawk file
contains a subset of that list of fields, which are actually the ones you
are interested in.

I don't know for sure, but could it be that the attributes in the
Australian files are named in lower-case?  Maybe .dbffawk files are

> Despite no progress I feel I've made progress.

I can help a little, but I can't test it.  Or can I?  Can I get the
Australian weather alert APRS feed here in NZ?



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