[erlang-questions] io:request/2 documentation?

jm jeffm@REDACTED
Wed Mar 18 03:27:11 CET 2009

Robert Virding wrote:
> Hi Jeff,
> No io:request/2 has not been documented yet. All it does is to send 
> off a request to an io-server and wait for the reply. One reason for 
> not having documented it is that up until very recently the io-server 
> protocol has not been documented.
> This has now changed. In January I wrote a description of the older 
> io-server protocol. This description was included in my Erlang 
> Rationale document which you can find in the User Contributions 
> section of trapexit.org <http://trapexit.org>. A truly brilliant piece 
> of writing. .-) There is now also a freshly written description of the 
> newer io-server protocol which is included in the documentation of the 
> just released version R13-A in the user's guide section of stdlib. The 
> newer protocol is very similar to the older one, the main change is 
> providing for some extra parameters for handling unicode.

I've dug it up and managed to read some of it over lunch. Now, if I can 
just hide from customer complaints about our mail server being black 
list by hot mail long enough for it to be delisted I might be able 
finish it.
> You use io:request/2 in the same manner as it is shown in the leex and 
> yecc blogg. A very good description by the way.
Best overview I've seen ( I've been awaiting one) which actually shows 
how to use Leex and Yeec in practice. It's one thing to have manuals 
it's another to actually have a documented example which fills in the 

> It can *NOT* be directly used with a gen_tcp generated socket. An 
> io-server is a process which obeys the io-server protocol. It would, 
> however, not be very difficult to write an io-server which could 
> directly read/write against a gen_tcp socket. If someone could show me 
> a preferred way of setting up and talking to a socket I can fix the 
> io-server.
Sounds like a good idea I can see it being useful in many an app.



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