[Lazarus] Portable way to enumerate serial ports?

Bo Berglund bo.berglund at gmail.com
Sun Nov 28 00:06:56 CET 2010

On Sat, 27 Nov 2010 08:12:53 -0600, Paul Breneman
<list2010 at BrenemanLabs.com> wrote:

>Bo Berglund wrote:
>> Is there a way that one can use to list the actual serial ports
>> available on a system that will work on both Windows and Linux?
>> That is, is there a class/method or such already coded to give me a
>> list of com ports when called?
>> The com ports are differently named in Windows and Linux, but it
>> should be possible to get a list of ports actually available.
>> But not using a listing of dev with ttys in the name, because I have
>> found that in my test Linux systems there are always 4 of these even
>> though there is only hardware for a single port...
>I haven't found a very good way for Linux.  I modified the SynaSer Linux 
>code for the GetSerialPortNames function in the code on this page:
>   http://www.turbocontrol.com/simpleserial.htm
>Here is what I scan on Linux:
>     ScanForPorts( '/dev/ttyS*');
>     ScanForPorts( '/dev/ttyUSB*');
>     ScanForPorts( '/dev/ttyAM*'); // for ARM board

Are com ports on ARM based embedded Linux named 'ttyAM1', 'ttyAM2'

And how is the found "file" /dev/ttyS* verified as a real port?
I have found that on UBUNTU Linux there are always 4 such "files" even
though only one port actually exists.
/dev/ttyS4  (or possibly 0-1-2-3, can't remember right now)

Anyway I did get no communication at all using /dev/ttyS1, but when I
switched to /dev/ttyS2 I could get a connection to a program on
Windows. Mind you it was even possible to open the non-existing


Bo Berglund
Developer in Sweden

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