[aprssig] APRS device identifiers (tocalls.txt)

[John Langner WB2OSZ]

>   AFAIK your tocalls.txt file is only used by humans, no automatic tools.



Dire Wolf parses the tocalls.txt file each time it starts up.  This allows
users to download and use the most recent version.

It looks for lines with:

* Spaces in columns 1, 5, and 6.
* "AP" in columns 7 and 8.

Only leading upper case letters and digits are retained.  Lower case letters
are discarded for the matching string.  For example,

APBLO remains as APBLO.
APBLxx is shortened to APBL.
APBxxx is shortened to APB.

It searches for the longest match and does the right thing most of the time.
For example if we encountered APBL99, perform these compares, longest to
shortest.

APBLO		First 5 characters don't match.  Reject.
APBL 		First 4 characters do match.  Take this.
APB 		Don't get to this because there was a longer match.

Of course it doesn't handle the APnnnD / APnnnU case properly.  And it
wouldn't distinguish between the two APRXxx cases.


73,
John WB2OSZ