I know I've asked variations on this question before, but I keep cheating the answer by using the "to count" option with a known number of bytes. Thus far, I've been able to structure everything to always be the same number of bytes received (the current version uses 30 bytes) so I can just always use:

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wait for data from source connectionName to count 30

Now, however, I can no longer use that crutch, as I have data coming which I cannot make other than 12 bytes.

So.

I want to be able to read an arbitrary amount of bytes, stopping after there are no more bytes to read. To that end, I have the following questions:

1. Is a wait statement even needed? Could I replace it with a loop? Something like

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do
read byte from source connectionName to count 1
stick that byte somewhere
loop until no more bytes

How do I tell if there are no more bytes to read?

2. If that doesn't work, then using no "to count" on the wait for data, will read one byte, yes? So I could do that loop above with a Wait and a Read, looping until there is no more data. But same question, how do I tell there is no more data to read?

3. Finally, if there is no way to tell no data is left, can I do:

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wait for 12 bytes
check to see if this fits the 12 byte data style
if yes, goto TwelveByteData
if no, wait for 18 more bytes
do the ThirtyByteData stuff

Will the 18 bytes be "lost" if no one is waiting for them?

Thanks for all the help. I promise I'll have something cool to show from all of this, one day!

Brian

I'd recommend your 2nd approach. The data won't be lost -- it'll be queued up. Untested pseudo code:

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   set twelveByteFormat to false
   set foo to read byte list from source "MyConnName" to count 12 timeout after 1000
   
   if false then -- check foo for 12 byte format here
      -- do something with 12 bytes of data here
      set twelveByteFormat to true
   end if
   
   if not twelveByteFormat then
      set foo to foo & (read byte list from source "MyConnName" to count 18 timeout after 1000)
      -- do something with 18 bytes of data here
   end if

Ok, I'll try that. Thanks.

Brian