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printf("Hey guys,\nMy name is Petar.");

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Hey guys,
My name is Petar.

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int i = 25;
printf("The number is: %i\nBecause I said so...", i);

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The number is: 25Because I said so...

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printf("The number is: %i \nBecause I said so...", i);

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The number is: 25
Because I said so...

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// Writes a single character out to the screen.
extern void putchar(char c)
{
    // The background colour is black (0), the foreground is white (15).
    u8int backColour = 0;
    u8int foreColour = 15;

    // The attribute byte is made up of two nibbles - the lower being the 
    // foreground colour, and the upper the background colour.
    u8int  attributeByte = (backColour << 4) | (foreColour & 0x0F);
    // The attribute byte is the top 8 bits of the word we have to send to the
    // VGA board.
    u16int attribute = attributeByte << 8;
    u16int *location;

    // Handle a backspace, by moving the cursor back one space
    if (c == 0x08 && cursor_x)
    {
        cursor_x--;
    }

    // Handle a tab by increasing the cursor's X, but only to a point
    // where it is divisible by 8.
    else if (c == 0x09)
    {
        cursor_x = (cursor_x+8) & ~(8-1);
    }

    // Handle carriage return
    else if (c == '\r')
    {
        cursor_x = 0;
    }

    // Handle newline by moving cursor back to left and increasing the row
    else if (c == '\n')
    {
        cursor_x = 0;
        cursor_y++;
    }
    // Handle any other printable character.
    else if(c >= ' ')
    {
        location = video_memory + (cursor_y*80 + cursor_x);
        *location = c | attribute;
        cursor_x++;
    }

    // Check if we need to insert a new line because we have reached the end
    // of the screen.
    if (cursor_x >= 80)
    {
        cursor_x = 0;
        cursor_y ++;
    }

    // Scroll the screen if needed.
    scroll();
    // Move the hardware cursor.
    move_cursor();

}

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     /* Format a string and print it on the screen, just like the libc
        function printf. */
     extern void
     printf (const char *format, ...)
{
       char **arg = (char **) &format;
       int c;
       char buf[20];

	int len;
	int i = 0;
	char * str;
	char *s;
	int *ip;

	int flags;		/* flags to number() */

	int field_width;	/* width of output field */
	int precision;		/* min. # of digits for integers; max
				   number of chars for from string */
	int qualifier;		/* 'h', 'l', or 'L' for integer fields */

while ((c = *format++) != 0)
         {
	if (c != '%') 
		putchar(c);
           else
             {
               char *p;
     
               c = *format++;

	/* process flags */
		flags = 0;
		repeat:
			++format;		/* this also skips first '%' */
			switch (*format) {
				case '-': flags |= LEFT; goto repeat;
				case '+': flags |= PLUS; goto repeat;
				case ' ': flags |= SPACE; goto repeat;
				case '#': flags |= SPECIAL; goto repeat;
				case '0': flags |= ZEROPAD; goto repeat;
				}
		
		/* get field width */
		field_width = -1;
		if (is_digit(*format))
			field_width = skip_atoi(&format);
		else if (*format == '*') {
			/* it's the next argument */
			field_width = va_arg(arg, int);
			if (field_width < 0) {
				field_width = -field_width;
				flags |= LEFT;
			}
		}

		/* get the precision */
		precision = -1;
		if (*format == '.') {
			++format;	
			if (is_digit(*format))
				precision = skip_atoi(&format);
			else if (*format == '*') {
				/* it's the next argument */
				precision = va_arg(arg, int);
			}
			if (precision < 0)
				precision = 0;
		}

		/* get the conversion qualifier */
		qualifier = -1;
		if (*format == 'h' || *format == 'l' || *format == 'L') {
			qualifier = *format;
			++format;
		} 
       arg++;

		switch (c) {
		case 'c':
			if (!(flags & LEFT))
				while (--field_width > 0)
					*str++ = ' ';
			*str++ = (unsigned char) va_arg(arg, int);
			while (--field_width > 0)
				*str++ = ' ';
			break;

		case 's':
			p = *arg++;
                   if (! p)
                     p = "(null)";

		case 'o':
			str = number(str, va_arg(arg, unsigned long), 8,
				field_width, precision, flags);
			break;

		case 'p':
			if (field_width == -1) {
				field_width = 8;
				flags |= ZEROPAD;
			}
			str = number(str,
				(unsigned long) va_arg(arg, void *), 16,
				field_width, precision, flags);
			break;

		case 'x':
		   itoa (buf, c, *((int *) arg++));
                   p = buf;
                   goto string;
                   break;
		case 'X':
			str = number(str, va_arg(arg, unsigned long), 16,
				field_width, precision, flags);
			break;

		case 'd':
		case 'u':
		case 'i':
	           itoa (buf, c, *((int *) arg++));
                   p = buf;
                   goto string;
                   break;
		case 'n':
			ip = va_arg(arg, int *);
			*ip = (str - buf);
			break;
                string:
                   while (*p)
                     putchar (*p++);
                   break;

		default:
                   putchar (*((int *) arg++));
                   break;
			}
		}
	}
}

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if (c = '\n')
putchar('\n');
else ...

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   if (c != '%')
      putchar(c);
           else
             {
               char *p;
     
               c = *format++;

   /* process flags */
      flags = 0;
      repeat:
         ++format;      /* this also skips first '%' */

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void write(char *frm, ...) {
	__builtin_va_list list;
	
	__builtin_va_start(list, frm);
	
	for(; *frm != '\0'; frm++) {
		if(*frm == '%') {
			frm++;
			
			if(*frm == 'i')
				write_int(__builtin_va_arg(list, int));
			else if(*frm == 's')
				write_str(__builtin_va_arg(list, char *));
			else if(*frm == '%')
				write_char('%');
		}
		else if(*frm == '\n')
			newline();
		else
			write_char(*frm);
	}
}