Function hexchar

Sming/System/stringutil.cpp:65–74

}

char hexchar(unsigned char c)
{
	if(c < 10) {
		return (char)('0' + c);
	}
	if(c <= 15) {
		return (char)('a' + c - 10);
	}
	return '\0';
}

signed char unhex(char c)
{