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From: Rick Jones on 2 Apr 2010 16:49 Bill Cunningham <nospam(a)nspam.invalid> wrote: > "Rainer Weikusat" <rweikusat(a)mssgmbh.com> wrote in message > news:87y6h5k43x.fsf(a)fever.mssgmbh.com... > > I tried to point out the difference between a declaration and an > > operation. > In your example you used 0 as the 3rd argument. Should I have > done that? Or should I leave the port numbers the way they are? As already mentioned, the third argument to socket() is not a port number. The third argument is a specification of a *transport* protocol - eg TCP, UDP, etc. rick jones and don't forget the error checking... -- No need to believe in either side, or any side. There is no cause. There's only yourself. The belief is in your own precision. - Joubert these opinions are mine, all mine; HP might not want them anyway... :) feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH...
From: Ersek, Laszlo on 2 Apr 2010 17:02 On Fri, 2 Apr 2010, Rainer Weikusat wrote: > the socket API itself is not tied to either protocol or address > families. That depends on what you consider to be part of the BSD sockets API. In the end, you triggered me to follow up on this (originally I decided not to, since my reply wouldn't have helped the OP): On Fri, 2 Apr 2010, Rick Jones wrote: > the protocol argument to the socket() call is to specify the transport > protocol, not the service's port number in the transport protocol. Additionally, the transport protocol may not even have a "port number" concept. Or it may have a service identifier notion that is different from the 16-bit port numbers used with TCP and UDP. --o-- For example, SCTP could not be completely retrofitted to the BSD sockets API. I'm looking at the sctp_bindx() and sctp_connectx() manuals shipped with "lksctp-tools-1.0.11.tar.gz". Sure, with single local and remote addresses, one can use bind() and connect(), but then "protocol independent" excludes "multi-homing". The address structures taken by these functions are, in case of IPv4, "struct sockaddr_in" objects. If the SCTP designers had chosen different service identifiers than 16-bit port numbers, then even sockaddr_in could not have been used, as it includes a fixed member "sin_port" of type "in_port_t" (an unsigned integer type of exactly 16 bits) for specifying the service within the transport protocol. I guess "sin_port" was a premature abstraction when the API was designed. If you're implying getaddrinfo(), then I have to give it to you, it is protocol and address family independent <http://people.redhat.com/drepper/userapi-ipv6.html>. It is also one of the hardest-to-use functions in the SUS, IMHO. And you still may need sctp_connectx(). lacos
From: Rainer Weikusat on 2 Apr 2010 17:03 scott(a)slp53.sl.home (Scott Lurndal) writes: > Rainer Weikusat <rweikusat(a)mssgmbh.com> writes: >>Doug McIntyre <merlyn(a)geeks.org> writes: >>> "Bill Cunningham" <nospam(a)nspam.invalid> writes: >>>>"Rick Jones" <rick.jones2(a)hp.com> wrote: >>> >>>>> Do definitely get either Unix Network Programming or some similar >>>>> work. It will be invaluable. >>> >>>> I'm just afraid that it will talk only about AF_UNIX and not get into >>>>internet networking. I understand there is a differenct in unix socket used >>>>internally by the machine and internet communication. >>> >>> There's very little use of AF_UNIX compared to AF_INET in the real >>> world, >> >>PF_UNIX sockets are the preferable method for IPC on a single >>system. Also, the socket API itself is not tied to either protocol or >>address families. > > preferable by whom? People who understand IPC.
From: Ian Collins on 2 Apr 2010 17:05 On 04/ 3/10 10:41 AM, Bill Cunningham wrote: > "Ian Collins"<ian-news(a)hotmail.com> wrote in message > news:81mvqdFsbU2(a)mid.individual.net... > >> Have you read the recommended books yet? > > Haven't look at it quite yet Ian but I intend too. As soon as I find the > books. While you wait, fix your clock! -- Ian Collins
From: Bill Cunningham on 2 Apr 2010 18:07
"Rick Jones" <rick.jones2(a)hp.com> wrote in message news:hp5l44$vtc$1(a)usenet01.boi.hp.com... > Bill Cunningham <nospam(a)nspam.invalid> wrote: >> "Rick Jones" <rick.jones2(a)hp.com> wrote in message >> news:hp5ejk$sm3$3(a)usenet01.boi.hp.com... > >> > Do definitely get either Unix Network Programming or some similar >> > work. It will be invaluable. > >> I'm just afraid that it will talk only about AF_UNIX and not get >> into internet networking. I understand there is a differenct in unix >> socket used internally by the machine and internet communication. > > Do not let the title fool you "Unix Network Programming" spends a > great deal of time on internet networking - perhaps more so than on > AF_UNIX. > > http://www.amazon.com/Unix-Network-Programming-Sockets-Networking/dp/0131411551/ref=sr_1_1?ie=UTF8&s=books&qid=1270241419&sr=8-1 > > This would probably make a good companion: > > http://www.amazon.com/Data-Computer-Communications-William-Stallings/dp/0132433109/ref=sr_1_1?ie=UTF8&s=books&qid=1270241586&sr=1-1 > > rick jones I just bought one by Kochans. Is it any good? Bill |