xref: /freebsd/lib/libc/stdlib/strfmon.c (revision aed23bc4ceaab17b4717b9f4dab300cd372f801b)
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 <stdarg.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 
41 /* internal flags */
42 #define	NEED_GROUPING		0x01	/* print digits grouped (default) */
43 #define	SIGN_POSN_USED		0x02	/* '+' or '(' usage flag */
44 #define	LOCALE_POSN		0x04	/* use locale defined +/- (default) */
45 #define	PARENTH_POSN		0x08	/* enclose negative amount in () */
46 #define	SUPRESS_CURR_SYMBOL	0x10	/* supress the currency from output */
47 #define	LEFT_JUSTIFY		0x20	/* left justify */
48 #define	USE_INTL_CURRENCY	0x40	/* use international currency symbol */
49 #define IS_NEGATIVE		0x80	/* is argument value negative ? */
50 
51 /* internal macros */
52 #define PRINT(CH) do {						\
53 	if (dst >= s + maxsize) 				\
54 		goto e2big_error;				\
55 	*dst++ = CH;						\
56 } while (0)
57 
58 #define PRINTS(STR) do {					\
59 	char *tmps = STR;					\
60 	while (*tmps != '\0')					\
61 		PRINT(*tmps++);					\
62 } while (0)
63 
64 #define GET_NUMBER(VAR)	do {					\
65 	VAR = 0;						\
66 	while (isdigit((unsigned char)*fmt)) {			\
67 		VAR *= 10;					\
68 		VAR += *fmt - '0';				\
69 		fmt++;						\
70 	}							\
71 } while (0)
72 
73 #define GRPCPY(howmany) do {					\
74 	int i = howmany;					\
75 	while (i-- > 0) {					\
76 		avalue_size--;					\
77 		*--bufend = *(avalue+avalue_size+padded);	\
78 	}							\
79 } while (0)
80 
81 #define GRPSEP do {						\
82 	*--bufend = thousands_sep;				\
83 	groups++;						\
84 } while (0)
85 
86 static void __setup_vars(int, char *, char *, char *, char **);
87 static int __calc_left_pad(int, char *);
88 static char *__format_grouped_double(double, int *, int, int, int);
89 
90 ssize_t
91 strfmon(char * __restrict s, size_t maxsize, const char * __restrict format,
92     ...)
93 {
94 	va_list		ap;
95 	char 		*dst;		/* output destination pointer */
96 	const char 	*fmt;		/* current format poistion pointer */
97 	struct lconv 	*lc;		/* pointer to lconv structure */
98 	char		*asciivalue;	/* formatted double pointer */
99 
100 	int		flags;		/* formatting options */
101 	int		pad_char;	/* padding character */
102 	int		pad_size;	/* pad size */
103 	int		width;		/* field width */
104 	int		left_prec;	/* left precision */
105 	int		right_prec;	/* right precision */
106 	double		value;		/* just value */
107 	char		space_char = ' '; /* space after currency */
108 
109 	char		cs_precedes,	/* values gathered from struct lconv */
110 			sep_by_space,
111 			sign_posn,
112 			*signstr,
113 			*currency_symbol;
114 
115 	char		*tmpptr;	/* temporary vars */
116 	int		*ntmp;
117 
118         va_start(ap, format);
119 
120 	lc = localeconv();
121 	dst = s;
122 	fmt = format;
123 	asciivalue = NULL;
124 	currency_symbol = NULL;
125 	pad_size = 0;
126 
127 	while (*fmt) {
128 		/* pass nonformating characters AS IS */
129 		if (*fmt != '%')
130 			goto literal;
131 
132 		/* '%' found ! */
133 
134 		/* "%%" mean just '%' */
135 		if (*(fmt+1) == '%') {
136 			fmt++;
137 	literal:
138 			PRINT(*fmt++);
139 			continue;
140 		}
141 
142 		/* set up initial values */
143 		flags = (NEED_GROUPING|LOCALE_POSN);
144 		pad_char = ' ';		/* padding character is "space" */
145 		left_prec = -1;		/* no left precision specified */
146 		right_prec = -1;	/* no right precision specified */
147 		width = -1;		/* no width specified */
148 		value = 0;		/* we have no value to print now */
149 
150 		/* Flags */
151 		while (1) {
152 			switch (*++fmt) {
153 				case '=':	/* fill character */
154 					pad_char = *++fmt;
155 					if (pad_char == '\0')
156 						goto format_error;
157 					continue;
158 				case '^':	/* not group currency  */
159 					flags &= ~(NEED_GROUPING);
160 					continue;
161 				case '+':	/* use locale defined signs */
162 					if (flags & SIGN_POSN_USED)
163 						goto format_error;
164 					flags |= (SIGN_POSN_USED|LOCALE_POSN);
165 					continue;
166 				case '(':	/* enclose negatives with () */
167 					if (flags & SIGN_POSN_USED)
168 						goto format_error;
169 					flags |= (SIGN_POSN_USED|PARENTH_POSN);
170 					continue;
171 				case '!':	/* suppress currency symbol */
172 					flags |= SUPRESS_CURR_SYMBOL;
173 					continue;
174 				case '-':	/* alignment (left)  */
175 					flags |= LEFT_JUSTIFY;
176 					continue;
177 				case '#':	/* left || right precision */
178 				case '.':
179 					if (*fmt == '#')
180 						ntmp = &left_prec;
181 					else
182 						ntmp = &right_prec;
183 
184 					if (!isdigit((unsigned char)*++fmt))
185 						goto format_error;
186 					GET_NUMBER(*ntmp);
187 					fmt--;
188 					continue;
189 				default:
190 					break;
191 			}
192 			break;
193 		}
194 
195 		/* field Width */
196 		if (isdigit((unsigned char)*fmt)) {
197 			GET_NUMBER(width);
198 			/* Do we have enough space to put number with
199 			 * required width ?
200 			 */
201 			if (dst + width >= s + maxsize)
202 				goto e2big_error;
203 		}
204 
205 		/* Conversion Characters */
206 		switch (*fmt++) {
207 			case 'i':	/* use internaltion currency format */
208 				flags |= USE_INTL_CURRENCY;
209 				break;
210 			case 'n':	/* use national currency format */
211 				flags &= ~(USE_INTL_CURRENCY);
212 				break;
213 			default:	/* required character is missing or
214 					   premature EOS */
215 				goto format_error;
216 		}
217 
218 		if (flags & USE_INTL_CURRENCY) {
219 			currency_symbol = strdup(lc->int_curr_symbol);
220 			if (currency_symbol != NULL)
221 				space_char = *(currency_symbol+3);
222 		} else
223 			currency_symbol = strdup(lc->currency_symbol);
224 
225 		if (currency_symbol == NULL)
226 			goto end_error;			/* ENOMEM. */
227 
228 		/* value itself */
229 		value = va_arg(ap, double);
230 
231 		/* detect sign */
232 		if (value < 0) {
233 			flags |= IS_NEGATIVE;
234 			value = -value;
235 		}
236 
237 		/* fill left_prec with amount of padding chars */
238 		if (left_prec >= 0) {
239 			pad_size = __calc_left_pad((flags ^ IS_NEGATIVE),
240 							currency_symbol) -
241 				   __calc_left_pad(flags, currency_symbol);
242 			if (pad_size < 0)
243 				pad_size = 0;
244 		}
245 
246 		asciivalue = __format_grouped_double(value, &flags,
247 				left_prec, right_prec, pad_char);
248 		if (asciivalue == NULL)
249 			goto end_error;		/* errno already set     */
250 						/* to ENOMEM by malloc() */
251 
252 		/* set some variables for later use */
253 		__setup_vars(flags, &cs_precedes, &sep_by_space,
254 				&sign_posn, &signstr);
255 
256 		/*
257 		 * Description of some LC_MONETARY's values:
258 		 *
259 		 * p_cs_precedes & n_cs_precedes
260 		 *
261 		 * = 1 - $currency_symbol precedes the value
262 		 *       for a monetary quantity with a non-negative value
263 		 * = 0 - symbol succeeds the value
264 		 *
265 		 * p_sep_by_space & n_sep_by_space
266                  *
267 		 * = 0 - no space separates $currency_symbol
268 		 *       from the value for a monetary quantity with a
269 		 *	 non-negative value
270 		 * = 1 - space separates the symbol from the value
271 		 * = 2 - space separates the symbol and the sign string,
272 		 *       if adjacent.
273                  *
274 		 * p_sign_posn & n_sign_posn
275                  *
276 		 * = 0 - parentheses enclose the quantity and the
277 		 *	 $currency_symbol
278 		 * = 1 - the sign string precedes the quantity and the
279 		 *       $currency_symbol
280 		 * = 2 - the sign string succeeds the quantity and the
281 		 *       $currency_symbol
282 		 * = 3 - the sign string precedes the $currency_symbol
283 		 * = 4 - the sign string succeeds the $currency_symbol
284                  *
285 		 */
286 
287 		tmpptr = dst;
288 
289 		while (pad_size-- > 0)
290 			PRINT(' ');
291 
292 		if (sign_posn == 0) {
293 			if (flags & IS_NEGATIVE)
294 				PRINT('(');
295 			else
296 				PRINT(' ');
297 		}
298 
299 		if (cs_precedes == 1) {
300 			if (sign_posn == 1 || sign_posn == 3) {
301 				PRINTS(signstr);
302 				if (sep_by_space == 2)		/* XXX: ? */
303 					PRINT(' ');
304 			}
305 
306 			if (!(flags & SUPRESS_CURR_SYMBOL)) {
307 				PRINTS(currency_symbol);
308 
309 				if (sign_posn == 4) {
310 					if (sep_by_space == 2)
311 						PRINT(space_char);
312 					PRINTS(signstr);
313 					if (sep_by_space == 1)
314 						PRINT(' ');
315 				} else if (sep_by_space == 1)
316 					PRINT(space_char);
317 			}
318 		} else if (sign_posn == 1)
319 			PRINTS(signstr);
320 
321 		PRINTS(asciivalue);
322 
323 		if (cs_precedes == 0) {
324 			if (sign_posn == 3) {
325 				if (sep_by_space == 1)
326 					PRINT(' ');
327 				PRINTS(signstr);
328 			}
329 
330 			if (!(flags & SUPRESS_CURR_SYMBOL)) {
331 				if ((sign_posn == 3 && sep_by_space == 2)
332 				    || (sep_by_space == 1
333 				    && (sign_posn = 0
334 				    || sign_posn == 1
335 				    || sign_posn == 2
336 				    || sign_posn == 4)))
337 					PRINT(space_char);
338 				PRINTS(currency_symbol); /* XXX: len */
339 				if (sign_posn == 4) {
340 					if (sep_by_space == 2)
341 						PRINT(' ');
342 					PRINTS(signstr);
343 				}
344 			}
345 		}
346 
347 		if (sign_posn == 2) {
348 			if (sep_by_space == 2)
349 				PRINT(' ');
350 			PRINTS(signstr);
351 		}
352 
353 		if (sign_posn == 0 && (flags & IS_NEGATIVE))
354 			PRINT(')');
355 
356 		if (dst - tmpptr < width) {
357 			if (flags & LEFT_JUSTIFY) {
358 				while (dst - tmpptr <= width)
359 					PRINT(' ');
360 			} else {
361 				pad_size = dst-tmpptr;
362 				memmove(tmpptr + width-pad_size, tmpptr,
363 				    pad_size);
364 				memset(tmpptr, ' ', width-pad_size);
365 				dst += width-pad_size;
366 			}
367 		}
368 	}
369 
370 	PRINT('\0');
371 	va_end(ap);
372 	return (dst - s - 1);	/* return size of put data except trailing '\0' */
373 
374 e2big_error:
375 	errno = E2BIG;
376 	goto end_error;
377 
378 format_error:
379 	errno = EINVAL;
380 
381 end_error:
382 	if (asciivalue != NULL)
383 		free(asciivalue);
384 	if (currency_symbol != NULL)
385 		free(currency_symbol);
386 	va_end(ap);
387 	return (-1);
388 }
389 
390 static void
391 __setup_vars(int flags, char *cs_precedes, char *sep_by_space,
392 		char *sign_posn, char **signstr) {
393 
394 	struct lconv *lc = localeconv();
395 
396 	if (flags & IS_NEGATIVE) {
397 		*cs_precedes = lc->n_cs_precedes;
398 		*sep_by_space = lc->n_sep_by_space;
399 		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->n_sign_posn;
400 		*signstr = (lc->negative_sign == '\0') ? "-"
401 		    : lc->negative_sign;
402 	} else {
403 		*cs_precedes = lc->p_cs_precedes;
404 		*sep_by_space = lc->p_sep_by_space;
405 		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->p_sign_posn;
406 		*signstr = lc->positive_sign;
407 	}
408 
409 	/* Set defult values for unspecified information. */
410 	if (*cs_precedes != 0)
411 		*cs_precedes = 1;
412 	if (*sep_by_space == CHAR_MAX)
413 		*sep_by_space = 0;
414 	if (*sign_posn == CHAR_MAX)
415 		*sign_posn = 0;
416 }
417 
418 static int
419 __calc_left_pad(int flags, char *cur_symb) {
420 
421 	char cs_precedes, sep_by_space, sign_posn, *signstr;
422 	int left_chars = 0;
423 
424 	__setup_vars(flags, &cs_precedes, &sep_by_space, &sign_posn, &signstr);
425 
426 	if (cs_precedes != 0) {
427 		left_chars += strlen(cur_symb);
428 		if (sep_by_space != 0)
429 			left_chars++;
430 	}
431 
432 	switch (sign_posn) {
433 		case 1:
434 			left_chars += strlen(signstr);
435 			break;
436 		case 3:
437 		case 4:
438 			if (cs_precedes != 0)
439 				left_chars += strlen(signstr);
440 	}
441 	return (left_chars);
442 }
443 
444 static int
445 get_groups(int size, char *grouping) {
446 
447 	int	chars = 0;
448 
449 	if (*grouping == CHAR_MAX || *grouping <= 0)	/* no grouping ? */
450 		return (0);
451 
452 	while (size > (int)*grouping) {
453 		chars++;
454 		size -= (int)*grouping++;
455 		/* no more grouping ? */
456 		if (*grouping == CHAR_MAX)
457 			break;
458 		/* rest grouping with same value ? */
459 		if (*grouping == 0) {
460 			chars += (size - 1) / *(grouping - 1);
461 			break;
462 		}
463 	}
464 	return (chars);
465 }
466 
467 /* convert double to ASCII */
468 static char *
469 __format_grouped_double(double value, int *flags,
470 			int left_prec, int right_prec, int pad_char) {
471 
472 	char		*rslt;
473 	char		*avalue;
474 	int		avalue_size;
475 	char		fmt[32];
476 
477 	size_t		bufsize;
478 	char		*bufend;
479 
480 	int		padded;
481 
482 	struct lconv	*lc = localeconv();
483 	char		*grouping;
484 	char		decimal_point;
485 	char		thousands_sep;
486 
487 	int groups = 0;
488 
489 	grouping = lc->mon_grouping;
490 	decimal_point = *lc->mon_decimal_point;
491 	if (decimal_point == '\0') {
492 		decimal_point = *lc->decimal_point;
493 		if (decimal_point == '\0')
494 			decimal_point = '.';
495 	}
496 	thousands_sep = *lc->mon_thousands_sep;
497 	if (thousands_sep == '\0')
498 		thousands_sep = *lc->thousands_sep;
499 
500 	/* fill left_prec with default value */
501 	if (left_prec == -1)
502 		left_prec = 0;
503 
504 	/* fill right_prec with default value */
505 	if (right_prec == -1) {
506                 if (*flags & USE_INTL_CURRENCY)
507                         right_prec = lc->int_frac_digits;
508                 else
509                         right_prec = lc->frac_digits;
510 
511 		if (right_prec == CHAR_MAX)	/* POSIX locale ? */
512 			right_prec = 2;
513 	}
514 
515 	if (*flags & NEED_GROUPING)
516 		left_prec += get_groups(left_prec, grouping);
517 
518 	/* convert to string */
519 	snprintf(fmt, sizeof(fmt), "%%%d.%df", left_prec + right_prec + 1,
520 	    right_prec);
521 	avalue_size = asprintf(&avalue, fmt, value);
522 	if (avalue_size < 0)
523 		return (NULL);
524 
525 	/* make sure that we've enough space for result string */
526 	bufsize = strlen(avalue)*2+1;
527 	rslt = malloc(bufsize);
528 	if (rslt == NULL) {
529 		free(avalue);
530 		return (NULL);
531 	}
532 	memset(rslt, 0, bufsize);
533 	bufend = rslt + bufsize - 1;	/* reserve space for trailing '\0' */
534 
535 	/* skip spaces at beggining */
536 	padded = 0;
537 	while (avalue[padded] == ' ') {
538 		padded++;
539 		avalue_size--;
540 	}
541 
542 	if (right_prec > 0) {
543 		bufend -= right_prec;
544 		memcpy(bufend, avalue + avalue_size+padded-right_prec,
545 		    right_prec);
546 		*--bufend = decimal_point;
547 		avalue_size -= (right_prec + 1);
548 	}
549 
550 	if ((*flags & NEED_GROUPING) &&
551 	    thousands_sep != '\0' &&	/* XXX: need investigation */
552 	    *grouping != CHAR_MAX &&
553 	    *grouping > 0) {
554 		while (avalue_size > (int)*grouping) {
555 			GRPCPY(*grouping);
556 			GRPSEP;
557 			grouping++;
558 
559 			/* no more grouping ? */
560 			if (*grouping == CHAR_MAX)
561 				break;
562 
563 			/* rest grouping with same value ? */
564 			if (*grouping == 0) {
565 				grouping--;
566 				while (avalue_size > *grouping) {
567 					GRPCPY(*grouping);
568 					GRPSEP;
569 				}
570 			}
571 		}
572 		if (avalue_size != 0)
573 			GRPCPY(avalue_size);
574 		padded -= groups;
575 
576 	} else {
577 		bufend -= avalue_size;
578 		memcpy(bufend, avalue+padded, avalue_size);
579 		if (right_prec == 0)
580 			padded--;	/* decrease assumed $decimal_point */
581 	}
582 
583 	/* do padding with pad_char */
584 	if (padded > 0) {
585 		bufend -= padded;
586 		memset(bufend, pad_char, padded);
587 	}
588 
589 	bufsize = bufsize - (rslt - bufend);
590 	memmove(rslt, bufend, bufsize);
591 	free(avalue);
592 	return (rslt);
593 }
594