xref: /freebsd/lib/libc/stdlib/strfmon.c (revision ad30f8e79bd1007cc2476e491bd21b4f5e389e0a)
1 /*-
2  * Copyright (c) 2001 Alexey Zelkin <phantom@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/types.h>
32 #include <ctype.h>
33 #include <errno.h>
34 #include <limits.h>
35 #include <locale.h>
36 #include <monetary.h>
37 #include <stdarg.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 
42 /* internal flags */
43 #define	NEED_GROUPING		0x01	/* print digits grouped (default) */
44 #define	SIGN_POSN_USED		0x02	/* '+' or '(' usage flag */
45 #define	LOCALE_POSN		0x04	/* use locale defined +/- (default) */
46 #define	PARENTH_POSN		0x08	/* enclose negative amount in () */
47 #define	SUPRESS_CURR_SYMBOL	0x10	/* supress the currency from output */
48 #define	LEFT_JUSTIFY		0x20	/* left justify */
49 #define	USE_INTL_CURRENCY	0x40	/* use international currency symbol */
50 #define IS_NEGATIVE		0x80	/* is argument value negative ? */
51 
52 /* internal macros */
53 #define PRINT(CH) do {						\
54 	if (dst >= s + maxsize) 				\
55 		goto e2big_error;				\
56 	*dst++ = CH;						\
57 } while (0)
58 
59 #define PRINTS(STR) do {					\
60 	char *tmps = STR;					\
61 	while (*tmps != '\0')					\
62 		PRINT(*tmps++);					\
63 } while (0)
64 
65 #define GET_NUMBER(VAR)	do {					\
66 	VAR = 0;						\
67 	while (isdigit((unsigned char)*fmt)) {			\
68 		if (VAR > INT_MAX / 10)				\
69 			goto e2big_error;			\
70 		VAR *= 10;					\
71 		VAR += *fmt - '0';				\
72 		if (VAR < 0)					\
73 			goto e2big_error;			\
74 		fmt++;						\
75 	}							\
76 } while (0)
77 
78 #define GRPCPY(howmany) do {					\
79 	int i = howmany;					\
80 	while (i-- > 0) {					\
81 		avalue_size--;					\
82 		*--bufend = *(avalue+avalue_size+padded);	\
83 	}							\
84 } while (0)
85 
86 #define GRPSEP do {						\
87 	*--bufend = thousands_sep;				\
88 	groups++;						\
89 } while (0)
90 
91 static void __setup_vars(int, char *, char *, char *, char **);
92 static int __calc_left_pad(int, char *);
93 static char *__format_grouped_double(double, int *, int, int, int);
94 
95 ssize_t
96 strfmon(char * __restrict s, size_t maxsize, const char * __restrict format,
97     ...)
98 {
99 	va_list		ap;
100 	char 		*dst;		/* output destination pointer */
101 	const char 	*fmt;		/* current format poistion pointer */
102 	struct lconv 	*lc;		/* pointer to lconv structure */
103 	char		*asciivalue;	/* formatted double pointer */
104 
105 	int		flags;		/* formatting options */
106 	int		pad_char;	/* padding character */
107 	int		pad_size;	/* pad size */
108 	int		width;		/* field width */
109 	int		left_prec;	/* left precision */
110 	int		right_prec;	/* right precision */
111 	double		value;		/* just value */
112 	char		space_char = ' '; /* space after currency */
113 
114 	char		cs_precedes,	/* values gathered from struct lconv */
115 			sep_by_space,
116 			sign_posn,
117 			*signstr,
118 			*currency_symbol;
119 
120 	char		*tmpptr;	/* temporary vars */
121 	int		sverrno;
122 
123         va_start(ap, format);
124 
125 	lc = localeconv();
126 	dst = s;
127 	fmt = format;
128 	asciivalue = NULL;
129 	currency_symbol = NULL;
130 	pad_size = 0;
131 
132 	while (*fmt) {
133 		/* pass nonformating characters AS IS */
134 		if (*fmt != '%')
135 			goto literal;
136 
137 		/* '%' found ! */
138 
139 		/* "%%" mean just '%' */
140 		if (*(fmt+1) == '%') {
141 			fmt++;
142 	literal:
143 			PRINT(*fmt++);
144 			continue;
145 		}
146 
147 		/* set up initial values */
148 		flags = (NEED_GROUPING|LOCALE_POSN);
149 		pad_char = ' ';		/* padding character is "space" */
150 		left_prec = -1;		/* no left precision specified */
151 		right_prec = -1;	/* no right precision specified */
152 		width = -1;		/* no width specified */
153 		value = 0;		/* we have no value to print now */
154 
155 		/* Flags */
156 		while (1) {
157 			switch (*++fmt) {
158 				case '=':	/* fill character */
159 					pad_char = *++fmt;
160 					if (pad_char == '\0')
161 						goto format_error;
162 					continue;
163 				case '^':	/* not group currency  */
164 					flags &= ~(NEED_GROUPING);
165 					continue;
166 				case '+':	/* use locale defined signs */
167 					if (flags & SIGN_POSN_USED)
168 						goto format_error;
169 					flags |= (SIGN_POSN_USED|LOCALE_POSN);
170 					continue;
171 				case '(':	/* enclose negatives with () */
172 					if (flags & SIGN_POSN_USED)
173 						goto format_error;
174 					flags |= (SIGN_POSN_USED|PARENTH_POSN);
175 					continue;
176 				case '!':	/* suppress currency symbol */
177 					flags |= SUPRESS_CURR_SYMBOL;
178 					continue;
179 				case '-':	/* alignment (left)  */
180 					flags |= LEFT_JUSTIFY;
181 					continue;
182 				default:
183 					break;
184 			}
185 			break;
186 		}
187 
188 		/* field Width */
189 		if (isdigit((unsigned char)*fmt)) {
190 			GET_NUMBER(width);
191 			/* Do we have enough space to put number with
192 			 * required width ?
193 			 */
194 			if ((unsigned int)width >= maxsize - (dst - s))
195 				goto e2big_error;
196 		}
197 
198 		/* Left precision */
199 		if (*fmt == '#') {
200 			if (!isdigit((unsigned char)*++fmt))
201 				goto format_error;
202 			GET_NUMBER(left_prec);
203 			if ((unsigned int)left_prec >= maxsize - (dst - s))
204 				goto e2big_error;
205 		}
206 
207 		/* Right precision */
208 		if (*fmt == '.') {
209 			if (!isdigit((unsigned char)*++fmt))
210 				goto format_error;
211 			GET_NUMBER(right_prec);
212 			if ((unsigned int)right_prec >= maxsize - (dst - s) -
213 			    left_prec)
214 				goto e2big_error;
215 		}
216 
217 		/* Conversion Characters */
218 		switch (*fmt++) {
219 			case 'i':	/* use internaltion currency format */
220 				flags |= USE_INTL_CURRENCY;
221 				break;
222 			case 'n':	/* use national currency format */
223 				flags &= ~(USE_INTL_CURRENCY);
224 				break;
225 			default:	/* required character is missing or
226 					   premature EOS */
227 				goto format_error;
228 		}
229 
230 		if (currency_symbol != NULL)
231 			free(currency_symbol);
232 		if (flags & USE_INTL_CURRENCY) {
233 			currency_symbol = strdup(lc->int_curr_symbol);
234 			if (currency_symbol != NULL)
235 				space_char = *(currency_symbol+3);
236 		} else
237 			currency_symbol = strdup(lc->currency_symbol);
238 
239 		if (currency_symbol == NULL)
240 			goto end_error;			/* ENOMEM. */
241 
242 		/* value itself */
243 		value = va_arg(ap, double);
244 
245 		/* detect sign */
246 		if (value < 0) {
247 			flags |= IS_NEGATIVE;
248 			value = -value;
249 		}
250 
251 		/* fill left_prec with amount of padding chars */
252 		if (left_prec >= 0) {
253 			pad_size = __calc_left_pad((flags ^ IS_NEGATIVE),
254 							currency_symbol) -
255 				   __calc_left_pad(flags, currency_symbol);
256 			if (pad_size < 0)
257 				pad_size = 0;
258 		}
259 
260 		if (asciivalue != NULL)
261 			free(asciivalue);
262 		asciivalue = __format_grouped_double(value, &flags,
263 				left_prec, right_prec, pad_char);
264 		if (asciivalue == NULL)
265 			goto end_error;		/* errno already set     */
266 						/* to ENOMEM by malloc() */
267 
268 		/* set some variables for later use */
269 		__setup_vars(flags, &cs_precedes, &sep_by_space,
270 				&sign_posn, &signstr);
271 
272 		/*
273 		 * Description of some LC_MONETARY's values:
274 		 *
275 		 * p_cs_precedes & n_cs_precedes
276 		 *
277 		 * = 1 - $currency_symbol precedes the value
278 		 *       for a monetary quantity with a non-negative value
279 		 * = 0 - symbol succeeds the value
280 		 *
281 		 * p_sep_by_space & n_sep_by_space
282                  *
283 		 * = 0 - no space separates $currency_symbol
284 		 *       from the value for a monetary quantity with a
285 		 *	 non-negative value
286 		 * = 1 - space separates the symbol from the value
287 		 * = 2 - space separates the symbol and the sign string,
288 		 *       if adjacent.
289                  *
290 		 * p_sign_posn & n_sign_posn
291                  *
292 		 * = 0 - parentheses enclose the quantity and the
293 		 *	 $currency_symbol
294 		 * = 1 - the sign string precedes the quantity and the
295 		 *       $currency_symbol
296 		 * = 2 - the sign string succeeds the quantity and the
297 		 *       $currency_symbol
298 		 * = 3 - the sign string precedes the $currency_symbol
299 		 * = 4 - the sign string succeeds the $currency_symbol
300                  *
301 		 */
302 
303 		tmpptr = dst;
304 
305 		while (pad_size-- > 0)
306 			PRINT(' ');
307 
308 		if (sign_posn == 0 && (flags & IS_NEGATIVE))
309 			PRINT('(');
310 
311 		if (cs_precedes == 1) {
312 			if (sign_posn == 1 || sign_posn == 3) {
313 				PRINTS(signstr);
314 				if (sep_by_space == 2)		/* XXX: ? */
315 					PRINT(' ');
316 			}
317 
318 			if (!(flags & SUPRESS_CURR_SYMBOL)) {
319 				PRINTS(currency_symbol);
320 
321 				if (sign_posn == 4) {
322 					if (sep_by_space == 2)
323 						PRINT(space_char);
324 					PRINTS(signstr);
325 					if (sep_by_space == 1)
326 						PRINT(' ');
327 				} else if (sep_by_space == 1)
328 					PRINT(space_char);
329 			}
330 		} else if (sign_posn == 1)
331 			PRINTS(signstr);
332 
333 		PRINTS(asciivalue);
334 
335 		if (cs_precedes == 0) {
336 			if (sign_posn == 3) {
337 				if (sep_by_space == 1)
338 					PRINT(' ');
339 				PRINTS(signstr);
340 			}
341 
342 			if (!(flags & SUPRESS_CURR_SYMBOL)) {
343 				if ((sign_posn == 3 && sep_by_space == 2)
344 				    || (sep_by_space == 1
345 				    && (sign_posn == 0
346 				    || sign_posn == 1
347 				    || sign_posn == 2
348 				    || sign_posn == 4)))
349 					PRINT(space_char);
350 				PRINTS(currency_symbol); /* XXX: len */
351 				if (sign_posn == 4) {
352 					if (sep_by_space == 2)
353 						PRINT(' ');
354 					PRINTS(signstr);
355 				}
356 			}
357 		}
358 
359 		if (sign_posn == 2) {
360 			if (sep_by_space == 2)
361 				PRINT(' ');
362 			PRINTS(signstr);
363 		}
364 
365 		if (sign_posn == 0 && (flags & IS_NEGATIVE))
366 			PRINT(')');
367 
368 		if (dst - tmpptr < width) {
369 			if (flags & LEFT_JUSTIFY) {
370 				while (dst - tmpptr < width)
371 					PRINT(' ');
372 			} else {
373 				pad_size = dst-tmpptr;
374 				memmove(tmpptr + width-pad_size, tmpptr,
375 				    pad_size);
376 				memset(tmpptr, ' ', width-pad_size);
377 				dst += width-pad_size;
378 			}
379 		}
380 	}
381 
382 	PRINT('\0');
383 	va_end(ap);
384 	free(asciivalue);
385 	free(currency_symbol);
386 	return (dst - s - 1);	/* return size of put data except trailing '\0' */
387 
388 e2big_error:
389 	errno = E2BIG;
390 	goto end_error;
391 
392 format_error:
393 	errno = EINVAL;
394 
395 end_error:
396 	sverrno = errno;
397 	if (asciivalue != NULL)
398 		free(asciivalue);
399 	if (currency_symbol != NULL)
400 		free(currency_symbol);
401 	errno = sverrno;
402 	va_end(ap);
403 	return (-1);
404 }
405 
406 static void
407 __setup_vars(int flags, char *cs_precedes, char *sep_by_space,
408 		char *sign_posn, char **signstr) {
409 
410 	struct lconv *lc = localeconv();
411 
412 	if ((flags & IS_NEGATIVE) && (flags & USE_INTL_CURRENCY)) {
413 		*cs_precedes = lc->int_n_cs_precedes;
414 		*sep_by_space = lc->int_n_sep_by_space;
415 		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->int_n_sign_posn;
416 		*signstr = (lc->negative_sign[0] == '\0') ? "-"
417 		    : lc->negative_sign;
418 	} else if (flags & USE_INTL_CURRENCY) {
419 		*cs_precedes = lc->int_p_cs_precedes;
420 		*sep_by_space = lc->int_p_sep_by_space;
421 		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->int_p_sign_posn;
422 		*signstr = lc->positive_sign;
423 	} else if (flags & IS_NEGATIVE) {
424 		*cs_precedes = lc->n_cs_precedes;
425 		*sep_by_space = lc->n_sep_by_space;
426 		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->n_sign_posn;
427 		*signstr = (lc->negative_sign[0] == '\0') ? "-"
428 		    : lc->negative_sign;
429 	} else {
430 		*cs_precedes = lc->p_cs_precedes;
431 		*sep_by_space = lc->p_sep_by_space;
432 		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->p_sign_posn;
433 		*signstr = lc->positive_sign;
434 	}
435 
436 	/* Set defult values for unspecified information. */
437 	if (*cs_precedes != 0)
438 		*cs_precedes = 1;
439 	if (*sep_by_space == CHAR_MAX)
440 		*sep_by_space = 0;
441 	if (*sign_posn == CHAR_MAX)
442 		*sign_posn = 0;
443 }
444 
445 static int
446 __calc_left_pad(int flags, char *cur_symb) {
447 
448 	char cs_precedes, sep_by_space, sign_posn, *signstr;
449 	int left_chars = 0;
450 
451 	__setup_vars(flags, &cs_precedes, &sep_by_space, &sign_posn, &signstr);
452 
453 	if (cs_precedes != 0) {
454 		left_chars += strlen(cur_symb);
455 		if (sep_by_space != 0)
456 			left_chars++;
457 	}
458 
459 	switch (sign_posn) {
460 		case 1:
461 			left_chars += strlen(signstr);
462 			break;
463 		case 3:
464 		case 4:
465 			if (cs_precedes != 0)
466 				left_chars += strlen(signstr);
467 	}
468 	return (left_chars);
469 }
470 
471 static int
472 get_groups(int size, char *grouping) {
473 
474 	int	chars = 0;
475 
476 	if (*grouping == CHAR_MAX || *grouping <= 0)	/* no grouping ? */
477 		return (0);
478 
479 	while (size > (int)*grouping) {
480 		chars++;
481 		size -= (int)*grouping++;
482 		/* no more grouping ? */
483 		if (*grouping == CHAR_MAX)
484 			break;
485 		/* rest grouping with same value ? */
486 		if (*grouping == 0) {
487 			chars += (size - 1) / *(grouping - 1);
488 			break;
489 		}
490 	}
491 	return (chars);
492 }
493 
494 /* convert double to ASCII */
495 static char *
496 __format_grouped_double(double value, int *flags,
497 			int left_prec, int right_prec, int pad_char) {
498 
499 	char		*rslt;
500 	char		*avalue;
501 	int		avalue_size;
502 	char		fmt[32];
503 
504 	size_t		bufsize;
505 	char		*bufend;
506 
507 	int		padded;
508 
509 	struct lconv	*lc = localeconv();
510 	char		*grouping;
511 	char		decimal_point;
512 	char		thousands_sep;
513 
514 	int groups = 0;
515 
516 	grouping = lc->mon_grouping;
517 	decimal_point = *lc->mon_decimal_point;
518 	if (decimal_point == '\0')
519 		decimal_point = *lc->decimal_point;
520 	thousands_sep = *lc->mon_thousands_sep;
521 	if (thousands_sep == '\0')
522 		thousands_sep = *lc->thousands_sep;
523 
524 	/* fill left_prec with default value */
525 	if (left_prec == -1)
526 		left_prec = 0;
527 
528 	/* fill right_prec with default value */
529 	if (right_prec == -1) {
530                 if (*flags & USE_INTL_CURRENCY)
531                         right_prec = lc->int_frac_digits;
532                 else
533                         right_prec = lc->frac_digits;
534 
535 		if (right_prec == CHAR_MAX)	/* POSIX locale ? */
536 			right_prec = 2;
537 	}
538 
539 	if (*flags & NEED_GROUPING)
540 		left_prec += get_groups(left_prec, grouping);
541 
542 	/* convert to string */
543 	snprintf(fmt, sizeof(fmt), "%%%d.%df", left_prec + right_prec + 1,
544 	    right_prec);
545 	avalue_size = asprintf(&avalue, fmt, value);
546 	if (avalue_size < 0)
547 		return (NULL);
548 
549 	/* make sure that we've enough space for result string */
550 	bufsize = strlen(avalue)*2+1;
551 	rslt = calloc(1, bufsize);
552 	if (rslt == NULL) {
553 		free(avalue);
554 		return (NULL);
555 	}
556 	bufend = rslt + bufsize - 1;	/* reserve space for trailing '\0' */
557 
558 	/* skip spaces at beggining */
559 	padded = 0;
560 	while (avalue[padded] == ' ') {
561 		padded++;
562 		avalue_size--;
563 	}
564 
565 	if (right_prec > 0) {
566 		bufend -= right_prec;
567 		memcpy(bufend, avalue + avalue_size+padded-right_prec,
568 		    right_prec);
569 		*--bufend = decimal_point;
570 		avalue_size -= (right_prec + 1);
571 	}
572 
573 	if ((*flags & NEED_GROUPING) &&
574 	    thousands_sep != '\0' &&	/* XXX: need investigation */
575 	    *grouping != CHAR_MAX &&
576 	    *grouping > 0) {
577 		while (avalue_size > (int)*grouping) {
578 			GRPCPY(*grouping);
579 			GRPSEP;
580 			grouping++;
581 
582 			/* no more grouping ? */
583 			if (*grouping == CHAR_MAX)
584 				break;
585 
586 			/* rest grouping with same value ? */
587 			if (*grouping == 0) {
588 				grouping--;
589 				while (avalue_size > *grouping) {
590 					GRPCPY(*grouping);
591 					GRPSEP;
592 				}
593 			}
594 		}
595 		if (avalue_size != 0)
596 			GRPCPY(avalue_size);
597 		padded -= groups;
598 
599 	} else {
600 		bufend -= avalue_size;
601 		memcpy(bufend, avalue+padded, avalue_size);
602 		if (right_prec == 0)
603 			padded--;	/* decrease assumed $decimal_point */
604 	}
605 
606 	/* do padding with pad_char */
607 	if (padded > 0) {
608 		bufend -= padded;
609 		memset(bufend, pad_char, padded);
610 	}
611 
612 	bufsize = bufsize - (bufend - rslt) + 1;
613 	memmove(rslt, bufend, bufsize);
614 	free(avalue);
615 	return (rslt);
616 }
617