xref: /freebsd/lib/libc/stdlib/strfmon.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
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 		VAR *= 10;					\
69 		VAR += *fmt - '0';				\
70 		fmt++;						\
71 	}							\
72 } while (0)
73 
74 #define GRPCPY(howmany) do {					\
75 	int i = howmany;					\
76 	while (i-- > 0) {					\
77 		avalue_size--;					\
78 		*--bufend = *(avalue+avalue_size+padded);	\
79 	}							\
80 } while (0)
81 
82 #define GRPSEP do {						\
83 	*--bufend = thousands_sep;				\
84 	groups++;						\
85 } while (0)
86 
87 static void __setup_vars(int, char *, char *, char *, char **);
88 static int __calc_left_pad(int, char *);
89 static char *__format_grouped_double(double, int *, int, int, int);
90 
91 ssize_t
92 strfmon(char * __restrict s, size_t maxsize, const char * __restrict format,
93     ...)
94 {
95 	va_list		ap;
96 	char 		*dst;		/* output destination pointer */
97 	const char 	*fmt;		/* current format poistion pointer */
98 	struct lconv 	*lc;		/* pointer to lconv structure */
99 	char		*asciivalue;	/* formatted double pointer */
100 
101 	int		flags;		/* formatting options */
102 	int		pad_char;	/* padding character */
103 	int		pad_size;	/* pad size */
104 	int		width;		/* field width */
105 	int		left_prec;	/* left precision */
106 	int		right_prec;	/* right precision */
107 	double		value;		/* just value */
108 	char		space_char = ' '; /* space after currency */
109 
110 	char		cs_precedes,	/* values gathered from struct lconv */
111 			sep_by_space,
112 			sign_posn,
113 			*signstr,
114 			*currency_symbol;
115 
116 	char		*tmpptr;	/* temporary vars */
117 	int		sverrno;
118 
119         va_start(ap, format);
120 
121 	lc = localeconv();
122 	dst = s;
123 	fmt = format;
124 	asciivalue = NULL;
125 	currency_symbol = NULL;
126 	pad_size = 0;
127 
128 	while (*fmt) {
129 		/* pass nonformating characters AS IS */
130 		if (*fmt != '%')
131 			goto literal;
132 
133 		/* '%' found ! */
134 
135 		/* "%%" mean just '%' */
136 		if (*(fmt+1) == '%') {
137 			fmt++;
138 	literal:
139 			PRINT(*fmt++);
140 			continue;
141 		}
142 
143 		/* set up initial values */
144 		flags = (NEED_GROUPING|LOCALE_POSN);
145 		pad_char = ' ';		/* padding character is "space" */
146 		left_prec = -1;		/* no left precision specified */
147 		right_prec = -1;	/* no right precision specified */
148 		width = -1;		/* no width specified */
149 		value = 0;		/* we have no value to print now */
150 
151 		/* Flags */
152 		while (1) {
153 			switch (*++fmt) {
154 				case '=':	/* fill character */
155 					pad_char = *++fmt;
156 					if (pad_char == '\0')
157 						goto format_error;
158 					continue;
159 				case '^':	/* not group currency  */
160 					flags &= ~(NEED_GROUPING);
161 					continue;
162 				case '+':	/* use locale defined signs */
163 					if (flags & SIGN_POSN_USED)
164 						goto format_error;
165 					flags |= (SIGN_POSN_USED|LOCALE_POSN);
166 					continue;
167 				case '(':	/* enclose negatives with () */
168 					if (flags & SIGN_POSN_USED)
169 						goto format_error;
170 					flags |= (SIGN_POSN_USED|PARENTH_POSN);
171 					continue;
172 				case '!':	/* suppress currency symbol */
173 					flags |= SUPRESS_CURR_SYMBOL;
174 					continue;
175 				case '-':	/* alignment (left)  */
176 					flags |= LEFT_JUSTIFY;
177 					continue;
178 				default:
179 					break;
180 			}
181 			break;
182 		}
183 
184 		/* field Width */
185 		if (isdigit((unsigned char)*fmt)) {
186 			GET_NUMBER(width);
187 			/* Do we have enough space to put number with
188 			 * required width ?
189 			 */
190 			if (dst + width >= s + maxsize)
191 				goto e2big_error;
192 		}
193 
194 		/* Left precision */
195 		if (*fmt == '#') {
196 			if (!isdigit((unsigned char)*++fmt))
197 				goto format_error;
198 			GET_NUMBER(left_prec);
199 		}
200 
201 		/* Right precision */
202 		if (*fmt == '.') {
203 			if (!isdigit((unsigned char)*++fmt))
204 				goto format_error;
205 			GET_NUMBER(right_prec);
206 		}
207 
208 		/* Conversion Characters */
209 		switch (*fmt++) {
210 			case 'i':	/* use internaltion currency format */
211 				flags |= USE_INTL_CURRENCY;
212 				break;
213 			case 'n':	/* use national currency format */
214 				flags &= ~(USE_INTL_CURRENCY);
215 				break;
216 			default:	/* required character is missing or
217 					   premature EOS */
218 				goto format_error;
219 		}
220 
221 		if (flags & USE_INTL_CURRENCY) {
222 			currency_symbol = strdup(lc->int_curr_symbol);
223 			if (currency_symbol != NULL)
224 				space_char = *(currency_symbol+3);
225 		} else
226 			currency_symbol = strdup(lc->currency_symbol);
227 
228 		if (currency_symbol == NULL)
229 			goto end_error;			/* ENOMEM. */
230 
231 		/* value itself */
232 		value = va_arg(ap, double);
233 
234 		/* detect sign */
235 		if (value < 0) {
236 			flags |= IS_NEGATIVE;
237 			value = -value;
238 		}
239 
240 		/* fill left_prec with amount of padding chars */
241 		if (left_prec >= 0) {
242 			pad_size = __calc_left_pad((flags ^ IS_NEGATIVE),
243 							currency_symbol) -
244 				   __calc_left_pad(flags, currency_symbol);
245 			if (pad_size < 0)
246 				pad_size = 0;
247 		}
248 
249 		asciivalue = __format_grouped_double(value, &flags,
250 				left_prec, right_prec, pad_char);
251 		if (asciivalue == NULL)
252 			goto end_error;		/* errno already set     */
253 						/* to ENOMEM by malloc() */
254 
255 		/* set some variables for later use */
256 		__setup_vars(flags, &cs_precedes, &sep_by_space,
257 				&sign_posn, &signstr);
258 
259 		/*
260 		 * Description of some LC_MONETARY's values:
261 		 *
262 		 * p_cs_precedes & n_cs_precedes
263 		 *
264 		 * = 1 - $currency_symbol precedes the value
265 		 *       for a monetary quantity with a non-negative value
266 		 * = 0 - symbol succeeds the value
267 		 *
268 		 * p_sep_by_space & n_sep_by_space
269                  *
270 		 * = 0 - no space separates $currency_symbol
271 		 *       from the value for a monetary quantity with a
272 		 *	 non-negative value
273 		 * = 1 - space separates the symbol from the value
274 		 * = 2 - space separates the symbol and the sign string,
275 		 *       if adjacent.
276                  *
277 		 * p_sign_posn & n_sign_posn
278                  *
279 		 * = 0 - parentheses enclose the quantity and the
280 		 *	 $currency_symbol
281 		 * = 1 - the sign string precedes the quantity and the
282 		 *       $currency_symbol
283 		 * = 2 - the sign string succeeds the quantity and the
284 		 *       $currency_symbol
285 		 * = 3 - the sign string precedes the $currency_symbol
286 		 * = 4 - the sign string succeeds the $currency_symbol
287                  *
288 		 */
289 
290 		tmpptr = dst;
291 
292 		while (pad_size-- > 0)
293 			PRINT(' ');
294 
295 		if (sign_posn == 0 && (flags & IS_NEGATIVE))
296 			PRINT('(');
297 
298 		if (cs_precedes == 1) {
299 			if (sign_posn == 1 || sign_posn == 3) {
300 				PRINTS(signstr);
301 				if (sep_by_space == 2)		/* XXX: ? */
302 					PRINT(' ');
303 			}
304 
305 			if (!(flags & SUPRESS_CURR_SYMBOL)) {
306 				PRINTS(currency_symbol);
307 
308 				if (sign_posn == 4) {
309 					if (sep_by_space == 2)
310 						PRINT(space_char);
311 					PRINTS(signstr);
312 					if (sep_by_space == 1)
313 						PRINT(' ');
314 				} else if (sep_by_space == 1)
315 					PRINT(space_char);
316 			}
317 		} else if (sign_posn == 1)
318 			PRINTS(signstr);
319 
320 		PRINTS(asciivalue);
321 
322 		if (cs_precedes == 0) {
323 			if (sign_posn == 3) {
324 				if (sep_by_space == 1)
325 					PRINT(' ');
326 				PRINTS(signstr);
327 			}
328 
329 			if (!(flags & SUPRESS_CURR_SYMBOL)) {
330 				if ((sign_posn == 3 && sep_by_space == 2)
331 				    || (sep_by_space == 1
332 				    && (sign_posn == 0
333 				    || sign_posn == 1
334 				    || sign_posn == 2
335 				    || sign_posn == 4)))
336 					PRINT(space_char);
337 				PRINTS(currency_symbol); /* XXX: len */
338 				if (sign_posn == 4) {
339 					if (sep_by_space == 2)
340 						PRINT(' ');
341 					PRINTS(signstr);
342 				}
343 			}
344 		}
345 
346 		if (sign_posn == 2) {
347 			if (sep_by_space == 2)
348 				PRINT(' ');
349 			PRINTS(signstr);
350 		}
351 
352 		if (sign_posn == 0 && (flags & IS_NEGATIVE))
353 			PRINT(')');
354 
355 		if (dst - tmpptr < width) {
356 			if (flags & LEFT_JUSTIFY) {
357 				while (dst - tmpptr < width)
358 					PRINT(' ');
359 			} else {
360 				pad_size = dst-tmpptr;
361 				memmove(tmpptr + width-pad_size, tmpptr,
362 				    pad_size);
363 				memset(tmpptr, ' ', width-pad_size);
364 				dst += width-pad_size;
365 			}
366 		}
367 	}
368 
369 	PRINT('\0');
370 	va_end(ap);
371 	free(asciivalue);
372 	free(currency_symbol);
373 	return (dst - s - 1);	/* return size of put data except trailing '\0' */
374 
375 e2big_error:
376 	errno = E2BIG;
377 	goto end_error;
378 
379 format_error:
380 	errno = EINVAL;
381 
382 end_error:
383 	sverrno = errno;
384 	if (asciivalue != NULL)
385 		free(asciivalue);
386 	if (currency_symbol != NULL)
387 		free(currency_symbol);
388 	errno = sverrno;
389 	va_end(ap);
390 	return (-1);
391 }
392 
393 static void
394 __setup_vars(int flags, char *cs_precedes, char *sep_by_space,
395 		char *sign_posn, char **signstr) {
396 
397 	struct lconv *lc = localeconv();
398 
399 	if ((flags & IS_NEGATIVE) && (flags & USE_INTL_CURRENCY)) {
400 		*cs_precedes = lc->int_n_cs_precedes;
401 		*sep_by_space = lc->int_n_sep_by_space;
402 		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->int_n_sign_posn;
403 		*signstr = (lc->negative_sign == '\0') ? "-"
404 		    : lc->negative_sign;
405 	} else if (flags & USE_INTL_CURRENCY) {
406 		*cs_precedes = lc->int_p_cs_precedes;
407 		*sep_by_space = lc->int_p_sep_by_space;
408 		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->int_p_sign_posn;
409 		*signstr = lc->positive_sign;
410 	} else if (flags & IS_NEGATIVE) {
411 		*cs_precedes = lc->n_cs_precedes;
412 		*sep_by_space = lc->n_sep_by_space;
413 		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->n_sign_posn;
414 		*signstr = (lc->negative_sign == '\0') ? "-"
415 		    : lc->negative_sign;
416 	} else {
417 		*cs_precedes = lc->p_cs_precedes;
418 		*sep_by_space = lc->p_sep_by_space;
419 		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->p_sign_posn;
420 		*signstr = lc->positive_sign;
421 	}
422 
423 	/* Set defult values for unspecified information. */
424 	if (*cs_precedes != 0)
425 		*cs_precedes = 1;
426 	if (*sep_by_space == CHAR_MAX)
427 		*sep_by_space = 0;
428 	if (*sign_posn == CHAR_MAX)
429 		*sign_posn = 0;
430 }
431 
432 static int
433 __calc_left_pad(int flags, char *cur_symb) {
434 
435 	char cs_precedes, sep_by_space, sign_posn, *signstr;
436 	int left_chars = 0;
437 
438 	__setup_vars(flags, &cs_precedes, &sep_by_space, &sign_posn, &signstr);
439 
440 	if (cs_precedes != 0) {
441 		left_chars += strlen(cur_symb);
442 		if (sep_by_space != 0)
443 			left_chars++;
444 	}
445 
446 	switch (sign_posn) {
447 		case 1:
448 			left_chars += strlen(signstr);
449 			break;
450 		case 3:
451 		case 4:
452 			if (cs_precedes != 0)
453 				left_chars += strlen(signstr);
454 	}
455 	return (left_chars);
456 }
457 
458 static int
459 get_groups(int size, char *grouping) {
460 
461 	int	chars = 0;
462 
463 	if (*grouping == CHAR_MAX || *grouping <= 0)	/* no grouping ? */
464 		return (0);
465 
466 	while (size > (int)*grouping) {
467 		chars++;
468 		size -= (int)*grouping++;
469 		/* no more grouping ? */
470 		if (*grouping == CHAR_MAX)
471 			break;
472 		/* rest grouping with same value ? */
473 		if (*grouping == 0) {
474 			chars += (size - 1) / *(grouping - 1);
475 			break;
476 		}
477 	}
478 	return (chars);
479 }
480 
481 /* convert double to ASCII */
482 static char *
483 __format_grouped_double(double value, int *flags,
484 			int left_prec, int right_prec, int pad_char) {
485 
486 	char		*rslt;
487 	char		*avalue;
488 	int		avalue_size;
489 	char		fmt[32];
490 
491 	size_t		bufsize;
492 	char		*bufend;
493 
494 	int		padded;
495 
496 	struct lconv	*lc = localeconv();
497 	char		*grouping;
498 	char		decimal_point;
499 	char		thousands_sep;
500 
501 	int groups = 0;
502 
503 	grouping = lc->mon_grouping;
504 	decimal_point = *lc->mon_decimal_point;
505 	if (decimal_point == '\0')
506 		decimal_point = *lc->decimal_point;
507 	thousands_sep = *lc->mon_thousands_sep;
508 	if (thousands_sep == '\0')
509 		thousands_sep = *lc->thousands_sep;
510 
511 	/* fill left_prec with default value */
512 	if (left_prec == -1)
513 		left_prec = 0;
514 
515 	/* fill right_prec with default value */
516 	if (right_prec == -1) {
517                 if (*flags & USE_INTL_CURRENCY)
518                         right_prec = lc->int_frac_digits;
519                 else
520                         right_prec = lc->frac_digits;
521 
522 		if (right_prec == CHAR_MAX)	/* POSIX locale ? */
523 			right_prec = 2;
524 	}
525 
526 	if (*flags & NEED_GROUPING)
527 		left_prec += get_groups(left_prec, grouping);
528 
529 	/* convert to string */
530 	snprintf(fmt, sizeof(fmt), "%%%d.%df", left_prec + right_prec + 1,
531 	    right_prec);
532 	avalue_size = asprintf(&avalue, fmt, value);
533 	if (avalue_size < 0)
534 		return (NULL);
535 
536 	/* make sure that we've enough space for result string */
537 	bufsize = strlen(avalue)*2+1;
538 	rslt = malloc(bufsize);
539 	if (rslt == NULL) {
540 		free(avalue);
541 		return (NULL);
542 	}
543 	memset(rslt, 0, bufsize);
544 	bufend = rslt + bufsize - 1;	/* reserve space for trailing '\0' */
545 
546 	/* skip spaces at beggining */
547 	padded = 0;
548 	while (avalue[padded] == ' ') {
549 		padded++;
550 		avalue_size--;
551 	}
552 
553 	if (right_prec > 0) {
554 		bufend -= right_prec;
555 		memcpy(bufend, avalue + avalue_size+padded-right_prec,
556 		    right_prec);
557 		*--bufend = decimal_point;
558 		avalue_size -= (right_prec + 1);
559 	}
560 
561 	if ((*flags & NEED_GROUPING) &&
562 	    thousands_sep != '\0' &&	/* XXX: need investigation */
563 	    *grouping != CHAR_MAX &&
564 	    *grouping > 0) {
565 		while (avalue_size > (int)*grouping) {
566 			GRPCPY(*grouping);
567 			GRPSEP;
568 			grouping++;
569 
570 			/* no more grouping ? */
571 			if (*grouping == CHAR_MAX)
572 				break;
573 
574 			/* rest grouping with same value ? */
575 			if (*grouping == 0) {
576 				grouping--;
577 				while (avalue_size > *grouping) {
578 					GRPCPY(*grouping);
579 					GRPSEP;
580 				}
581 			}
582 		}
583 		if (avalue_size != 0)
584 			GRPCPY(avalue_size);
585 		padded -= groups;
586 
587 	} else {
588 		bufend -= avalue_size;
589 		memcpy(bufend, avalue+padded, avalue_size);
590 		if (right_prec == 0)
591 			padded--;	/* decrease assumed $decimal_point */
592 	}
593 
594 	/* do padding with pad_char */
595 	if (padded > 0) {
596 		bufend -= padded;
597 		memset(bufend, pad_char, padded);
598 	}
599 
600 	bufsize = bufsize - (bufend - rslt) + 1;
601 	memmove(rslt, bufend, bufsize);
602 	free(avalue);
603 	return (rslt);
604 }
605