Re: How to do a blocking read from a serial device?
Re: How to do a blocking read from a serial device?
- Subject: Re: How to do a blocking read from a serial device?
- From: Michael Smith <email@hidden>
- Date: Wed, 12 Jul 2006 12:09:32 -0700
On Jul 12, 2006, at 12:02 PM, email@hidden wrote:
On Jul 11, 2006, at 12:11 PM, Michael Smith wrote:
On Jul 11, 2006, at 12:04 PM, email@hidden
wrote:
Read(2) will block if there is no data so there's no need to sleep.
Using select(2) is one way to go about it but with only one file
descriptor/socket, it seems pointless to me.
Select(2) makes timeout handling (mandatory for disconnectable
devices such as those attached by USB or serial interfaces) much
simpler.
Shouldn't that return -1 or 0?
USB device removal can usually be detected and the device will typically
be torn down, yes. Serial device removal is much more problematic;
there
is no reliable way to know that your device has been unplugged, other
than that it fails to respond in the expected fashion.
= Mike
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