How To Get Rid of Null Terminator In Pointer For WriteFile Function

[anonymousxyz]

Hello and thank you!
I am attempting to send the character 'a' to a microcontroller. Although I am sending the character a, there is also another character being sent and I am 95% sure it is '\0' because that is what my microcontroller is printing out.

Here is the code:

bool Port::writePort(char *toWrite)
{
	if(WriteFile(hSerial, toWrite, sizeof(toWrite), &bytesRead, NULL)){
		cout << "Write Successful\n";
		return true;
	}else{
		cout << "Write failed";
		return false;
	}
}

int main(int argc, char *argv[])
{
	Port myPort;

	char *toSend = argv[1];

	myPort.writePort(toSend);

    return 0;
}

Side question, how can I run/debug my code from the IDE and give main initial parameters?

Edit: I've been doing it so far via cmd

[LB]

sizeof(toWrite) is the size of the pointer, not the length of the string.
You want to use strlen(toWrite)

[andywestken]

I am attempting to send the character 'a' to a microcontroller.

If you're just trying to send a single char to your port (the first char in your string?) then you need:

// Writes just the first byte of the string (assumed to be
// chars -- and sizeof(char) == 1)
WriteFile(hSerial, toWrite, 1, &bytesWritten, NULL))

or you can enforce the use of chars

// toWrite now a char, not a char*
writeFile(hSerial, &toWrite, 1, &bytesWritten, NULL);

with

char toSend = argv[1][0];

But if you do want to write the whole string (while comes from a command line?), it is probably best to include the null terminator, which requires strlen(toWrite) + 1.

how can I run/debug my code from the IDE

That depends on which IDE you mean.

For Visual Studio, see your project's properties. On the "Debugging" tab, there's a chance to define the "Command Arguments".

Andy

[anonymousxyz]

Aha, thank you very much, both of you!
And thanks Andy, for the MSVS help.