Avoid trailing zeroes in printf()

Question

I keep stumbling on the format specifiers for the printf() family of functions. What I want is to be able to print a double (or float) with a maximum given number of digits

Answer 1

I search the string (starting rightmost) for the first character in the range 1 to 9 (ASCII value 49-57) then null (set to 0) each char right of it - see below:

void stripTrailingZeros(void) { 
    //This finds the index of the rightmost ASCII char[1-9] in array
    //All elements to the left of this are nulled (=0)
    int i = 20;
    unsigned char char1 = 0; //initialised to ensure entry to condition below

    while ((char1 > 57) || (char1 < 49)) {
        i--;
        char1 = sprintfBuffer[i];
    }

    //null chars left of i
    for (int j = i; j < 20; j++) {
        sprintfBuffer[i] = 0;
    }
}