Re: Bug in Guile's Posix Networking

[Ken Raeburn]

On Feb 13, 2011, at 08:55, Noah Lavine wrote:
> OS X, which I use, has a somewhat weird field-naming situation. The
> generic sockaddr structure has sa_len, but sockaddr_in has a sin_len
> field.

No, that's normal for a traditional C/UNIX API.  Each structure's field names 
use a prefix that's an abbreviation for the struct type.  So sockaddr_in uses 
sin_ and not sa_.

If this were a pure C++ API we'd have inheritance and could just specify a 
length field in the base class "sockaddr" from which the others might be 
derived.  But for this ancient C/UNIX API, we have different structures with 
different field names, and must cast the pointers.

> The code I was fixing is creating a sockaddr_in, so in order to
> use the sa_len field I would have had to cast a sockaddr_in to a
> sockaddr, and it just seemed cleaner to use the sin_len field. It's no
> big deal either way, though - this would affect probably 10 or fewer
> lines of code no matter what.

Yes, that's fine; just ditch the test for sockaddr (no _in) having a sin_len 
field.

Ken