serial ports

Alexander J. Herrmann ping2weltall@gmail.com
Sun Apr 23 14:40:00 GMT 2006


And what is the final answer? Is there a

/dev/ttySx 
in Cygwin which can be used in Perl or C, even if I can not see it with ls?
Alex

Dave Korn wrote:

>On 23 April 2006 05:44, David Christensen wrote:
>
>  
>
>>Dave Korn wrote:
>>    
>>
>>>Well then, that's a really good argument for just using the builtin
>>>access that cygwin provides through /dev/ttySx instead, isn't it?
>>>The way Oliver's original post reads suggests that he was just thrown
>>>off by not seeing any devices under the virtual /dev dir, but that
>>>doesn't mean it won't work for him if he tries it.
>>>      
>>>
>>As they say in Perl parlance, TIMTOWDI ("there's more than one way to do
>>it").
>>    
>>
>
>  I thought perl dudes tend to say things like TIMTOTNHAFTWTDAGT ("there is
>more than one thousand nine hundread and forty-three ways to do any given
>thing")....
>
>  
>
>>If Oliver is a C, etc., programmer fluent in the /dev/ttySx API, then
>>it could work.  
>>    
>>
>
>  But you have a level confusion here.  What you refer to as "the /dev/ttySx
>API" is not a feature of C, any more than it's a feature of Perl.  It's a
>feature of POSIX programming environments.  If you're on a POSIX system, you
>get /dev/ttySx in *every* programming language - Perl, C, the whole lot.
>
>  Also, the very fact that Oliver was asking after where the /dev/ttySx
>devices had gone to is kind of a giveaway that he feels happy using it, isn't
>it?  You need to actually /read/ people's questions and tailor your answers to
>what they've asked, not what you feel would be good for them.
>
>  
>
>>But if Oliver wants to write idiomatic Perl and get his
>>application going faster and easier,
>>    
>>
>
>  You should perhaps have stated these conditions in your first post, it's a
>bit less-informative to leave out the conditions which make a piece of advice
>valid when you offer it.
>
>  
>
>>then he wants to use standard and accepted CPAN libraries 
>>    
>>
>
>  Perl needs a library just to open and read and write a file and perhaps send
>a few ioctls ????
>
>  BTW, to me, "print >>$FILE" *is* fairly "idiomatic perl", but I'm just not a
>Perl expert I guess.  Is this a case of "Real perl programmers don't output to
>files!" ?
>
>  
>
>>rather than roll his own (especially non-portable ones).  
>>    
>>
>
>  And you happen to know what Oliver wants to do?  I didn't see him make any
>suggestion he was going to roll hiw own libraries and use non-portable ones.
>You're starting to make an /awful/ lot of assumptions here without having any
>explicit knowledge of what Oliver actually wants.
>
>  
>
>>Win32::SerialPort (Windows) and Device::SerialPort (Unix/Linux) are
>>the best approach under Perl. One or both may work under Cygwin; I haven't
>>done serial port programming in a number of years, and needed ActiveState
>>Perl the last time I did.
>>    
>>
>
>  Trying to mix win32 perl and cygwin is a recipe for tears.  Sure, use CPAN
>modules, that is of course a good idea; but if the *nix one doesn't work under
>cygwin, fixing it or rolling your own or even just using the bog-standard file
>i/o features in perl is definitely far safer.
>
>  
>
>> YMMV. 
>>    
>>
>
>  Well, that's the point isn't it?  The OP just asked for help because he
>wasn't sure of the mapping of com ports to /dev/ttySx numbers.  Your advice to
>install active state perl and some win32 module seems a bit more superfluous
>effort than merely subtracting one from the com port number and using
>/dev/ttySx.
>
>  Do perl people also say WDITEWWYCDITHWATTTALITB?  "Why do it the easy way
>when you can do it the hard way and take ten times as long into the bargain"?
>;)
>
>
>    cheers,
>      DaveK
>  
>

-- 
And God said"Let there be light."But then the program crashed because he was trying to access the 'light' property of a NULL universe pointer.

Alexander J. Herrmann
Analyst/Programmer
http://www.aiengine.org
Email: Ping2Weltall@Gmail.com


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