cat /dev/ttyS?

[Eric Blake]

> 
> oh, i found the 'cat /dev/ttyS1' really outputs, but it has a very
> *big* delay that leads me thought it does not response.   is the
> output buffered?  what do i do? thanks!

Yes, cat with no options calls read(), which typically uses buffers.  Try
cat -u to get unbuffered output.  Or there are other programs,
such as dd, which are better suited with options to tweak to get
unbuffered output.

--
Eric Blake
volunteer cygwin coreutils maintainer


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