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<== Date ==> <== Thread ==>

Subject: Re: stream/asyn devices
From: Emmanuel Mayssat <[email protected]>
To: epics <[email protected]>
Date: Thu, 26 Jul 2007 19:16:56 -0700
Update on stream device records

Stream records are actually quite simple to implement.
I found what appears to be bugs in the implementation, but some could
describe those as features. Mainly the entire part of the afternoon was
spend on trying to find out how the terminator is matched.

Although terminator appears to be of unlimited length in stream, it
seems that asyn impose its 2 chars limits for eos. As a result the
stream terminator consist of the last 2 char of its value.

Stream device can actually handle http connection (not permanent
connection) with the "disconnect" protocol option. That was a good
surprise.

The matching works well (once the terminator issue was handled), but I
would have loved traditional regex matching. Matching a complex/long
reply like a web page seems tedious.

But overall, I have been impressed by this record and would encourage
all of you to have a closer look at stream. BTW, I use stream from the
synApps-5.2 package.

--
Emmanuel Mayssat


On Thu, 2007-07-26 at 14:59 -0700, Emmanuel Mayssat wrote:
> Hello again,
> 
> I have a device which has a web server and a simple web page.
> My record should fetch the web page and extract the value between the
> <epics> and </epics> tags. Can asyn do that? ( it probably can ;)
> 
> Better yet, I looked at the streamDriver which is also said to work on
> TCP/IP. Can stream records do that?
> One could argue that the TCP/IP connection is not permanent (i.e the
> server kicks you out if the client is idle, but asyn should
> auto-reconnect right?)
> 
> http://epics.web.psi.ch/software/streamdevice/doc/
> 
> Also is stream the new devGpib ?
> 
> --
> Emmanuel
> 
> 
> 
> 
> 


Replies:
Re: stream/asyn devices Dirk Zimoch
References:
stream/asyn devices Emmanuel Mayssat

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