[aprssig] spaces in object names

[Lynn W. Deffenbaugh (Mr)]

According to the Watcom C runtime library function isprint(), "Space is 
printable".

Lynn (D) - KJ4ERJ

PS.  Simple program to ask...

#include <ctype.h>
#include <stdio.h>

int main(void)
{
    printf("Space is %s\n", isprint(' ')?"printable":"NOT printable");
    return isprint(' ');
}


Steve Dimse wrote:
> It has recently come to my attention that DStar objects are being sent 
> to APRS with an embedded space in the object name (like "K4HG A"). The 
> APRS spec states that objects names can be any printable character. As 
> it turned out this is a poor choice of words. Surprisingly to me, 
> whether space is printable is debatable. When I searched Google, the 
> first entry (wikipedia) and some others very clearly state it is not a 
> printable character. Other pages state it is a printable character. 
> This sort of ambiguity is obviously not desirable in the spec document.
>
> It never occurred to me to consider it printable, so my parser removed 
> all spaces as a lazy way to get rid of trailing spaces. This obvious 
> broke with these objects, the object "K4HG A   " became "K4HGA". This 
> was obviously a bug, and I've corrected it to match my interpretation 
> of the spec, namely object "K4HG A   " is invalid. I continue to 
> remove trailing spaces.
>
> The problem is readability. If you do not remove trailing spaces, 
> there can be six different entities on map that print as "K4HG", 
> distinguished on whether they have zero to five spaces after my 
> callsign. This is a problem for the tactical use of APRS. The same 
> argument applies to embedded spaces, where the number of spaces can be 
> difficult to judge with a proportional font.
>
> I've discussed this with Bob and he agrees, and will be making this 
> clarification on the spec addendum page. In looking over the log for 
> the last couple hours, I only see DStar objects with embedded spaces, 
> so there should not be any problems to other users from this 
> clarification.
>
> Those sending DStar objects, the easiest change to make would be to 
> simply replace the embedded space with a dash, so K4HG A becomes K4HG-A.
>
> Steve K4HG
>
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