Linux and ttyUSB0

> On Wed, Jun 18, 2008 at 04:10:39AM +0100, S??verin Lemaignan wrote:
>> Thanks, Dave, for the answer.
>>
>> > A slightly more difficult change would be to add an optional primitive for
>> > Unix/Linux that sets the serialPortBaseName string. That would let you control
>> > it from Squeak, and would not require any changes to the existing primitives.
>>
>> That's actually probably what I'll try to do. Stupid question, but
>> where can I fetch the sqUnixSerial.c file (and it's MacOS
>> counterpart)?
>
> Severin,
>
> The sqUnixSerial.c file is part of the external support code (as opposed
> to the parts that are distributed in the VMMaker package). The external
> support code is maintained in a Subversion repository at http://squeakvm.org
> and you will also find it at the various VM home pages. If you are working
> with Linux for example, just grab one of Ian's distributions on
> http://squeakvm.org/unix/.
>
> The sqUnixSerial.c file is in platforms/unix/plugins/SerialPlugin.
> The corresponding support code for other platforms is in e.g.
> platforms/Mac OS/plugins/serialPlugin.
>
> I don't know enough about Mac OS to give any guidance there, but the
> support code for SerialPlugin looks like it might be for some older
> version of Mac OS. I understand that on OS X you can actually use
> a plugin from the unix sources, but I'm afraid I don't know the details.
>
> Dave
>
>
>

> On Sun, Jan 04, 2009 at 11:54:22PM +0100, S??verin Lemaignan wrote:
>>
>> For each of them, I need to get the port name. I did like that
>> (copy-pasted from another plugin):
>>
>>         int spName;
>>         char * spNameIndex;
>>
>>
>>         spName = interpreterProxy->stackValue(0);
>>         interpreterProxy->success(interpreterProxy->isBytes(spName));
>>         spNameIndex = interpreterProxy->firstIndexableField(spName);
>>
>> But I probably do something wrong since if I call the primitive
>> "primSerialPortOpenByName" with "/dev/ttyACM0" as port name from
>> Squeak, the plugin code in sqUnixSerial.c receives a different string
>> ("/dev/ttyACM0_??????  @???w @???w "), thus failing to open the serial port.
>>
>> Does someone knows how to correctly transmit a string argument to a plugin?
>>
>
> S??verin,
>
> The trick here is that C expects strings to be null-terminated, and the Squeak
> string that you pass to the primitive does not have the trailing null.
>
> In general, you will want to copy the Squeak string contents into a freshly
> allocated char[] array of size one greater than the string length. There
> are a number of ways you can do this, but to give some examples you can
> look in OSProcessPlugin (available on SqueakSource in project OSProcessPlugin).
> The methods #transientCStringFromString: and #cStringFromString: provide
> two ways to do the conversion. As an example, here is a primitive from
> UnixOSProcessPlugin after it has been converted from Slang to C:
>
> /*      Call chdir(2) to change current working directory to the specified path string. Answer
>        nil for success, or errno on failure. */
>
> EXPORT(sqInt) primitiveChdir(void) {
>    extern int errno;
>    char * path;
>    sqInt aString;
>    sqInt len;
>    char *cString;
>    char *stringPtr;
>    sqInt newString;
>
>        /* begin transientCStringFromString: */
>        aString = interpreterProxy->stackObjectValue(0);
>        len = interpreterProxy->sizeOfSTArrayFromCPrimitive(interpreterProxy->arrayValueOf(aString));
>        interpreterProxy->pushRemappableOop(aString);
>        newString = interpreterProxy->instantiateClassindexableSize(interpreterProxy->classString(), len + 1);
>        stringPtr = interpreterProxy->arrayValueOf(interpreterProxy->popRemappableOop());
>        cString = interpreterProxy->arrayValueOf(newString);
>        (char *)strncpy(cString, stringPtr, len);
>        cString[len] = 0;
>        path = cString;
>        if (chdir(path)) {
>                interpreterProxy->pop(2);
>                interpreterProxy->push(interpreterProxy->nilObject());
>        } else {
>                interpreterProxy->pop(2);
>                interpreterProxy->pushInteger(errno);
>        }
> }
>
>
>> And by the way, happy new year to everybody!
>
> And to you as well!
>
> - Dave
>
>
>