pythonic malloc

[Karl Scalet]

kjockey schrieb:
> I have some simple UDP code that does:
> s.sendto("\xf0\x00\x02\x00rachel\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",addr)
> 
> This is OK, except that I'd like to change the text in the middle ("rachel",
> which is the hostname FWIW), and the NUL padding needs to go out to make
> the length 25 bytes (so the padding depends on the length of the name).
> 
> So I could do something like:
> retpacket = "\xf0\x00\x02\x00"+socket.gethostname()
> while len(retpacket) < 26:

shouldn't that be 25?

>      retpacket += "\x00"
> s.sendto(retpacket, addr)
> 
> But that feels "wrong". And Python in a Nutshell says its a bad idea  -
> "anti-idiom".
> 
> Can anyone show me the true path?

No idea, if it's the true path:

hn = socket.gethostname()
retpacket = '\xf0\x00\x02\x00%s%s' % (hn, (25-4-len(hn))*chr(0))
s.sendto(retpacket, addr)

Karl


> 
> Brad