/* *  linux/kernel/vsprintf.c * *  (C) 1991  Linus Torvalds *//* vsprintf.c -- Lars Wirzenius & Linus Torvalds. *//* * Wirzenius wrote this portably, Torvalds fucked it up :-) */#include <stdarg.h>#include <string.h> /* we use this so that we can do without the ctype library */#define is_digit(c)	((c) >= '0' && (c) <= '9')static int skip_atoi(const char **s){	int i=0;	while (is_digit(**s))		i = i*10 + *((*s)++) - '0';	return i;}#define ZEROPAD	1		/* pad with zero */#define SIGN	2		/* unsigned/signed long */#define PLUS	4		/* show plus */#define SPACE	8		/* space if plus */#define LEFT	16		/* left justified */#define SPECIAL	32		/* 0x */#define SMALL	64		/* use 'abcdef' instead of 'ABCDEF' */#define do_div(n,base) ({ \int __res; \__asm__("divl %4":"=a" (n),"=d" (__res):"0" (n),"1" (0),"r" (base)); \__res; })static char * number(char * str, int num, int base, int size, int precision	,int type){	char c,sign,tmp[36];	const char *digits="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";	int i;	if (type&SMALL) digits="0123456789abcdefghijklmnopqrstuvwxyz";	if (type&LEFT) type &= ~ZEROPAD;	if (base<2 || base>36)		return 0;	c = (type & ZEROPAD) ? '0' : ' ' ;	if (type&SIGN && num<0) {		sign='-';		num = -num;	} else		sign=(type&PLUS) ? '+' : ((type&SPACE) ? ' ' : 0);	if (sign) size--;	if (type&SPECIAL) {		if (base==16) size -= 2;		else if (base==8) size--;	}	i=0;	if (num==0)		tmp[i++]='0';	else while (num!=0)		tmp[i++]=digits[do_div(num,base)];	if (i>precision) precision=i;	size -= precision;	if (!(type&(ZEROPAD+LEFT)))		while(size-->0)			*str++ = ' ';	if (sign)		*str++ = sign;	if (type&SPECIAL) {		if (base==8)			*str++ = '0';		else if (base==16) {			*str++ = '0';			*str++ = digits[33];		}	}	if (!(type&LEFT))		while(size-->0)			*str++ = c;	while(i<precision--)		*str++ = '0';	while(i-->0)		*str++ = tmp[i];	while(size-->0)		*str++ = ' ';	return str;}int vsprintf(char *buf, const char *fmt, va_list args){	int len;	int i;	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 */	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 (is_digit(*fmt))			field_width = skip_atoi(&fmt);		else if (*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 (is_digit(*fmt))				precision = skip_atoi(&fmt);			else if (*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;		}		switch (*fmt) {		case 'c':			if (!(flags & LEFT))				while (--field_width > 0)					*str++ = ' ';			*str++ = (unsigned char) va_arg(args, int);			while (--field_width > 0)				*str++ = ' ';			break;		case 's':			s = va_arg(args, char *);			len = strlen(s);			if (precision < 0)				precision = len;			else if (len > precision)				len = precision;			if (!(flags & LEFT))				while (len < field_width--)					*str++ = ' ';			for (i = 0; i < len; ++i)				*str++ = *s++;			while (len < field_width--)				*str++ = ' ';			break;		case 'o':			str = number(str, va_arg(args, 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(args, void *), 16,				field_width, precision, flags);			break;		case 'x':			flags |= SMALL;		case 'X':			str = number(str, va_arg(args, unsigned long), 16,				field_width, precision, flags);			break;		case 'd':		case 'i':			flags |= SIGN;		case 'u':			str = number(str, va_arg(args, unsigned long), 10,				field_width, precision, flags);			break;		case 'n':			ip = va_arg(args, int *);			*ip = (str - buf);			break;		default:			if (*fmt != '%')				*str++ = '%';			if (*fmt)				*str++ = *fmt;			else				--fmt;			break;		}	}	*str = '\0';	return str-buf;}