printf.c 6.54 KB
Newer Older
1 2 3 4 5 6
/*
 *	BIRD Library -- Formatted Output
 *
 *	(c) 1991, 1992 Lars Wirzenius & Linus Torvalds
 *
 *	Hacked up for BIRD by Martin Mares <mj@ucw.cz>
7
 *	Buffer size limitation implemented by Martin Mares.
8 9 10 11 12
 */

#include "nest/bird.h"
#include "string.h"

Martin Mareš's avatar
Martin Mareš committed
13 14
#include <errno.h>

15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
/* 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 LARGE	64		/* use 'ABCDEF' instead of 'abcdef' */

#define do_div(n,base) ({ \
int __res; \
__res = ((unsigned long) n) % (unsigned) base; \
n = ((unsigned long) n) / (unsigned) base; \
__res; })

41 42
static char * number(char * str, long num, int base, int size, int precision,
	int type, int remains)
43 44 45 46 47
{
	char c,sign,tmp[66];
	const char *digits="0123456789abcdefghijklmnopqrstuvwxyz";
	int i;

48 49
	if (size >= 0 && (remains -= size) < 0)
		return NULL;
50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84
	if (type & LARGE)
		digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	if (type & LEFT)
		type &= ~ZEROPAD;
	if (base < 2 || base > 36)
		return 0;
	c = (type & ZEROPAD) ? '0' : ' ';
	sign = 0;
	if (type & SIGN) {
		if (num < 0) {
			sign = '-';
			num = -num;
			size--;
		} else if (type & PLUS) {
			sign = '+';
			size--;
		} else if (type & SPACE) {
			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;
85 86
	if (size < 0 && -size > remains)
		return NULL;
87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111
	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;
}

112
int bvsnprintf(char *buf, int size, const char *fmt, va_list args)
113 114 115 116
{
	int len;
	unsigned long num;
	int i, base;
117
	char *str, *start;
118 119 120 121 122 123 124 125 126
	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 */

127
	for (start=str=buf ; *fmt ; ++fmt, size-=(str-start), start=str) {
128
		if (*fmt != '%') {
129 130
			if (!size)
				return -1;
131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185
			*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 == '*') {
			++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 == '*') {
				++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;

186 187
		if (field_width > size)
			return -1;
188 189 190 191 192 193 194 195 196 197
		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;

Martin Mareš's avatar
Martin Mareš committed
198 199 200
		case 'm':
			s = strerror(errno);
			goto str;
201 202 203
		case 'M':
			s = strerror(va_arg(args, int));
			goto str;
204 205 206 207 208
		case 's':
			s = va_arg(args, char *);
			if (!s)
				s = "<NULL>";

Martin Mareš's avatar
Martin Mareš committed
209
		str:
210 211 212
			len = strlen(s);
			if (precision >= 0 && len > precision)
				len = precision;
213 214
			if (len > size)
				return -1;
215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231

			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 = number(str,
				(unsigned long) va_arg(args, void *), 16,
232 233 234
				field_width, precision, flags, size);
			if (!str)
				return -1;
235 236 237 238 239 240 241 242 243 244 245 246 247 248 249
			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;

		/* IP address */
		case 'I':
250 251
			if (size < STD_ADDRESS_P_LENGTH)
				return -1;
252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280
			if (flags & SPECIAL)
				str = ip_ntox(va_arg(args, ip_addr), str);
			else {
				len = ip_ntop(va_arg(args, ip_addr), str) - str;
				str += len;
				if (field_width >= 0)
					while (len++ < STD_ADDRESS_P_LENGTH)
						*str++ = ' ';
			}
			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:
281 282
			if (size < 2)
				return -1;
283 284 285 286 287 288 289 290 291 292 293
			if (*fmt != '%')
				*str++ = '%';
			if (*fmt)
				*str++ = *fmt;
			else
				--fmt;
			continue;
		}
		if (qualifier == 'l')
			num = va_arg(args, unsigned long);
		else if (qualifier == 'h') {
294
			num = (unsigned short) va_arg(args, int);
295
			if (flags & SIGN)
296
				num = (short) num;
297 298 299 300
		} else if (flags & SIGN)
			num = va_arg(args, int);
		else
			num = va_arg(args, unsigned int);
301 302 303
		str = number(str, num, base, field_width, precision, flags, size);
		if (!str)
			return -1;
304
	}
305 306
	if (!size)
		return -1;
307 308 309 310
	*str = '\0';
	return str-buf;
}

311 312 313 314 315
int bvsprintf(char *buf, const char *fmt, va_list args)
{
  return bvsnprintf(buf, 1000000000, fmt, args);
}

316 317
int bsprintf(char * buf, const char *fmt, ...)
{
318 319
  va_list args;
  int i;
320

321 322 323 324 325 326 327 328 329 330 331 332 333 334 335
  va_start(args, fmt);
  i=bvsnprintf(buf, 1000000000, fmt, args);
  va_end(args);
  return i;
}

int bsnprintf(char * buf, int size, const char *fmt, ...)
{
  va_list args;
  int i;

  va_start(args, fmt);
  i=bvsnprintf(buf, size, fmt, args);
  va_end(args);
  return i;
336
}