[aprssig] spaces in object names

Tapio Sokura oh2kku at iki.fi
Sat Aug 15 06:43:07 EDT 2009


Hi,

I can't resist dipping my spoon into the broth:

Some people here seem to be hung on the definition of printable and 
non-printable. There's an easy fix to that: explicitly define what byte 
values are acceptable in the spec.

Looking at the ASCII table my interpretation of this is byte values 
32-126 (decimal). If you want to keep the object field left justified, 
restricting the leftmost byte position to 33-126 decimal might be in order.

It's really that simple. An application should check that the object 
name is valid (= conforms to the spec) and if so, it's accepted into the 
application as is. No need to mangle anything. Stripping trailing white 
space doesn't really change an object because if you send the object, 
you need to pad the field with spaces anyway to make the field nine 
characters wide. "123456   " is the same thing as "123456" or "123456 " 
on the air and thus should be the same thing in an application.

   Tapio

PS. We really need an updated APRS specification document. The current 
mess with the 1.0.1 pdf and the various addendums to it just don't work. 
Application identifiers like the to-call lists and mic-e comment byte 
assignments, maybe even symbol lists, don't necessarily need to be in 
the spec, but just about everything else should be in one coherent document.




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