padding spaces to LCD display - Day of Week

Using Arduino Programming Questions
1

so many LCD clock example projects and I can't find a solution to LCD format adding trailing spaces.

here is my code:

char line0[16]; // declare 16 character array for line0 of i2C display.
char line1[16]; // declare 16 character array for line1 of i2C display.

char timeWeekDay[10];
strftime(timeWeekDay,10, "%A", &timeinfo); // returns day as text, longest is "Wednesday" 9 chars plus end char.
char timeDate[3]; // 2 digits plus end char
strftime(timeDate,3, "%02d", &timeinfo); // returns date as 2 digits "11"
char timeMonth[3];
strftime(timeMonth,4, "%B", &timeinfo); // returns month as chars "November" is cut down to "Nov".
sprintf(line0, "%s %s %s", timeWeekDay, timeDate, timeMonth); // weekday length can be 6,7,8 or 9 chars.

on Line0 of the LCD today, I see "Tuesday 17 Nov ", tomorrow "Wednesday 18 Nov", and the day after "Thursday 19 Novv". Day of week can be 6, 7, 8 or 9 in length. Very easy, just pad with spaces.
I've tried width specifiers as described in C++ sprintf tutorials. I've also found examples of using FOR loops to dynamically add spaces based on "string" length. 8 hours later, here I am, first Ardunio forum post.
The preference would be a width specifier added to the sprinf line, is this possible?

2

A simple way would be to use strlen to find out how long line0 is and print enough spaces to overwrite anything left over from yesterday.

Or you could fill a string with spaces and copy the text from line0 into it with memmove; not strcpy because that would carry over the terminating zero.

3

Just add a number to the %s in sprintf, such as %9s, to specify the field width.

Note that your char array is too short, there needs to be space for the terminating null character.

4

One common solution to lingering character is to overwrite the field/line with spaces first:

  lcd.setCursor(0,0);
  lcd.write(F("                "));  // Sixteen spaces
  lcd.setCursor(0,0);
  lcd.write(line0);