Re: Reading bytes from a TCP port

[Fredrik Appelberg]

address@hidden writes:

> Fredrik Appelberg <address@hidden> wrote:
>> 
>> Hello all, new chicken schemer here.
>> 
>> I'm writing an AMPQ client for fun (as One does) and can't figure out
>> the correct way to read from a TCP port. I want to block until input is
>> available, and then read all buffered data into a byte buffer (I'm using
>> bitstring, but it can be anything really). This is what I've come up with:
>> 
>> (let* ((buf (->bitstring ""))
>>        (first-byte (read-string 1 in)))
>>   (if (eq? #!eof first-byte)
>>       ... handle eof
>>       (begin 
>>         (bitstring-append! buf (string->bitstring (string-append first-byte 
>> (read-buffered in))))
>>         ... do something with buf))
>> 
>> It works okay, but it seems a bit clunky to me. Is there a more
>> idiomatic way of reading a byte buffer from a port?
>> 
>> Cheers,
>> -- Fredrik
>
> The read-u8vector procedure from SRFI-4 might be what you want:
>
> http://wiki.call-cc.org/man/5/Module%20srfi-4#vector-io

That seems to be a more natural way to read binary data, but there
doesn't seem to be a u8vector-analogue for read-buffered, which would
have been nice.

I guess the proper way to read an AMQP frame would be to begin by
reading the first 7 bytes, which contain the payload size, so that I
know how many more bytes to expect.

Anyhoo, thanks for pointing me in the right direction.

Cheers,
-- Fredrik