Serial Port Comms - How to "argument" the COM Port I want

[migadrenaline]

...I've tried in a lot of ways (windows.... GOD)......

......the whole program only send a specified character through the serial port at a specified speed - I just want to be able to specify the COM Port as well through the command line as a parameter (using argv[] .....

(otherwise I'll have to change the source code of the small program to the specified port whenever I change computer's and/or serial Port and/or usb Port (in the latest if using an adapter that's being not enumerated through its serial number) or whatever.. evertime the port needs to be changed....)

This is the only line of the program that specifies the Port to be used.....any ideias on changing it?

hSerial = CreateFile(
"\\\\.\\COM10", GENERIC_READ|GENERIC_WRITE, 0, NULL,
OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL );



thabks take care!

[Salem]

How are strings in general represented in your program?

char
wchar_t
TCHAR

Is it being compiled with _UNICODE defined?

Assuming char say, then

int main ( int argc, char *argv[] ) {
    char portname[100] = "\\\\.\\";
    if ( argc >= 2 ) {
      // command line arg is just say COM10
      strcat(portname,argv[1]);
    }
    hSerial = CreateFile(
portname, GENERIC_READ|GENERIC_WRITE, 0, NULL,
OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL );

}

If your program begins with WinMain() and not main(), then start with GetCommandLine.

[migadrenaline]

It worked great thanks


BUT.. Can you explain me why this didn't:

{
char portname[20]=arv[1];

hSerial = CreateFile("\\\\.\\%s", portname, GENERIC_READ|GENERIC_WRITE, 0, NULL,
OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL );
}

just because I think that "thecnicaly" it's the same you've done (but maybe it isn0't since it didn't work and your's did XD )


EDITED:
maybe it should be like this:
hSerial = CreateFile("\\\\.\\%s", GENERIC_READ|GENERIC_WRITE, 0, NULL,
OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL , portname);

thanks!

[Salem]

Because %s isn't something you can throw into any string in any function.

Substituting one string in another with %s only works with printf / fprintf / sprintf.

[migadrenaline]

FOR THOSE WHO JUST READ THIS IT WORKED PERFECTLY AS Salem SAID!



thanks a lot! take care bro!