Function printf_core

payloads/libpayload/libc/printf.c:432–670

* Print formatted string. * * Print string formatted according to the fmt parameter and variadic arguments. * Each formatting directive must have the following form: * * \% [ FLAGS ] [ WIDTH ] [ .PRECISION ] [ TYPE ] CONVERSION * * FLAGS:@n * - "#" Force to print prefix.For \%o conversion, the prefix is 0, for * \%x and \%X prefixes are 0x and 0X and for conversion \%b the * prefix i

 * @return	Number of characters printed, negative value on failure.
 */
static int printf_core(const char *fmt, struct printf_spec *ps, va_list ap)
{
	int i = 0;		/* Index of the currently processed char from fmt */
	int j = 0;		/* Index to the first not printed nonformating character */
	int end;
	int counter;		/* Counter of printed characters */
	int retval;		/* Used to store return values from called functions */
	char c;
	qualifier_t qualifier;	/* Type of argument */
	int base;		/* Base in which a numeric parameter will be printed */
	uint64_t number;	/* Argument value */
	size_t size;		/* Byte size of integer parameter */
	int width, precision;
	uint64_t flags;

	counter = 0;

	while ((c = fmt[i])) {
		/* Control character. */
		if (c == '%') {
			/* Print common characters if any processed. */
			if (i > j) {
				if ((retval = printf_putnchars(&fmt[j],
				    (size_t) (i - j), ps)) < 0)
				    	return retval;
				counter += retval;
			}

			j = i;
			/* Parse modifiers. */
			flags = 0;
			end = 0;

			do {
				++i;
				switch (c = fmt[i]) {
				case '#':
					flags |= __PRINTF_FLAG_PREFIX;
					break;
				case '-':
					flags |= __PRINTF_FLAG_LEFTALIGNED;
					break;
				case '+':
					flags |= __PRINTF_FLAG_SHOWPLUS;
					break;
				case ' ':
					flags |= __PRINTF_FLAG_SPACESIGN;
					break;
				case '0':
					flags |= __PRINTF_FLAG_ZEROPADDED;
					break;
				default:
					end = 1;
				};

			} while (end == 0);

			/* Width & '*' operator. */