rem: vsprintf(char *buf, const char *fmt, va_list args)
add: vsprintf(char *buffer, const char *format, va_list args)
context: vsprintf(char *buf, const char *fmt, va_list args){	int len;	unsigned long long num;	int i, base;	char * str;	const char *s;	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 */	for (str = buf; *fmt; ++fmt) {		if (*fmt != '%') {			*str++ = *fmt;			continue;		}		/* process flags */		flags = 0;	repeat:		++fmt;		/* this also skips first '%' */		switch (*fmt) {			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 (isdigit(*fmt))			field_width = skip_atoi(&fmt);		else if (*fmt == '*') {			++fmt;			/* it's the next argument */			field_width = va_arg(args, int);			if (field_width < 0) {				field_width = -field_width;				flags |= LEFT;			}		}		/* get the precision */		precision = -1;		if (*fmt == '.') {			++fmt;				if (isdigit(*fmt))				precision = skip_atoi(&fmt);			else if (*fmt == '*') {				++fmt;				/* it's the next argument */				precision = va_arg(args, int);			}			if (precision < 0)				precision = 0;		}		/* get the conversion qualifier */		qualifier = -1;		if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L') {			qualifier = *fmt;			++fmt;		}		/* default base */		base = 10;		switch (*fmt) {		case 'c':			if (!(flags & LEFT))				while (--field_width > 0)					*str++ = ' ';			*str++ = (unsigned char) va_arg(args, int);			while (--field_width > 0)				*str++ = ' ';			continue;		case 's':			s = va_arg(args, char *);			if (!s)				s = "<NULL>";			len = strnlen(s, precision);			if (!(flags & LEFT))				while (len < field_width--)					*str++ = ' ';			for (i = 0; i < len; ++i)				*str++ = *s++;			while (len < field_width--)				*str++ = ' ';			continue;		case 'p':			if (field_width == -1) {				field_width = 2*sizeof(void *);				flags |= ZEROPAD;			}			str[0]= '0';			str[1]= 'x';			str = number(str+2,				(unsigned long) va_arg(args, void *), 16,				field_width, precision, flags);			continue;		case 'n':			if (qualifier == 'l') {				long * ip = va_arg(args, long *);				*ip = (str - buf);			} else {				int * ip = va_arg(args, int *);				*ip = (str - buf);			}			continue;		/* integer number formats - set up the flags and "break" */		case 'o':			base = 8;			break;		case 'X':			flags |= LARGE;		case 'x':			base = 16;			break;		case 'd':		case 'i':			flags |= SIGN;		case 'u':			break;		default:			if (*fmt != '%')				*str++ = '%';			if (*fmt)				*str++ = *fmt;			else				--fmt;			continue;		}		if (qualifier == 'L')			num = va_arg(args, unsigned long long);		else if (qualifier == 'l') {			num = va_arg(args, unsigned long);			if (flags & SIGN)				num = (long) num;		} else if (qualifier == 'h') {			num = (unsigned short) va_arg(args, int);			if (flags & SIGN)				num = (short) num;		} else if (flags & SIGN)			num = va_arg(args, int);		else			num = va_arg(args, unsigned int);		str = number(str, num, base, field_width, precision, flags);	}	*str = '\0';	return str - buf;}