xref: /freebsd/lib/libc/stdlib/strfmon.c (revision 729362425c09cf6b362366aabc6fb547eee8035a)
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		sverrno;
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 				default:
178 					break;
179 			}
180 			break;
181 		}
182 
183 		/* field Width */
184 		if (isdigit((unsigned char)*fmt)) {
185 			GET_NUMBER(width);
186 			/* Do we have enough space to put number with
187 			 * required width ?
188 			 */
189 			if (dst + width >= s + maxsize)
190 				goto e2big_error;
191 		}
192 
193 		/* Left precision */
194 		if (*fmt == '#') {
195 			if (!isdigit((unsigned char)*++fmt))
196 				goto format_error;
197 			GET_NUMBER(left_prec);
198 		}
199 
200 		/* Right precision */
201 		if (*fmt == '.') {
202 			if (!isdigit((unsigned char)*++fmt))
203 				goto format_error;
204 			GET_NUMBER(right_prec);
205 		}
206 
207 		/* Conversion Characters */
208 		switch (*fmt++) {
209 			case 'i':	/* use internaltion currency format */
210 				flags |= USE_INTL_CURRENCY;
211 				break;
212 			case 'n':	/* use national currency format */
213 				flags &= ~(USE_INTL_CURRENCY);
214 				break;
215 			default:	/* required character is missing or
216 					   premature EOS */
217 				goto format_error;
218 		}
219 
220 		if (flags & USE_INTL_CURRENCY) {
221 			currency_symbol = strdup(lc->int_curr_symbol);
222 			if (currency_symbol != NULL)
223 				space_char = *(currency_symbol+3);
224 		} else
225 			currency_symbol = strdup(lc->currency_symbol);
226 
227 		if (currency_symbol == NULL)
228 			goto end_error;			/* ENOMEM. */
229 
230 		/* value itself */
231 		value = va_arg(ap, double);
232 
233 		/* detect sign */
234 		if (value < 0) {
235 			flags |= IS_NEGATIVE;
236 			value = -value;
237 		}
238 
239 		/* fill left_prec with amount of padding chars */
240 		if (left_prec >= 0) {
241 			pad_size = __calc_left_pad((flags ^ IS_NEGATIVE),
242 							currency_symbol) -
243 				   __calc_left_pad(flags, currency_symbol);
244 			if (pad_size < 0)
245 				pad_size = 0;
246 		}
247 
248 		asciivalue = __format_grouped_double(value, &flags,
249 				left_prec, right_prec, pad_char);
250 		if (asciivalue == NULL)
251 			goto end_error;		/* errno already set     */
252 						/* to ENOMEM by malloc() */
253 
254 		/* set some variables for later use */
255 		__setup_vars(flags, &cs_precedes, &sep_by_space,
256 				&sign_posn, &signstr);
257 
258 		/*
259 		 * Description of some LC_MONETARY's values:
260 		 *
261 		 * p_cs_precedes & n_cs_precedes
262 		 *
263 		 * = 1 - $currency_symbol precedes the value
264 		 *       for a monetary quantity with a non-negative value
265 		 * = 0 - symbol succeeds the value
266 		 *
267 		 * p_sep_by_space & n_sep_by_space
268                  *
269 		 * = 0 - no space separates $currency_symbol
270 		 *       from the value for a monetary quantity with a
271 		 *	 non-negative value
272 		 * = 1 - space separates the symbol from the value
273 		 * = 2 - space separates the symbol and the sign string,
274 		 *       if adjacent.
275                  *
276 		 * p_sign_posn & n_sign_posn
277                  *
278 		 * = 0 - parentheses enclose the quantity and the
279 		 *	 $currency_symbol
280 		 * = 1 - the sign string precedes the quantity and the
281 		 *       $currency_symbol
282 		 * = 2 - the sign string succeeds the quantity and the
283 		 *       $currency_symbol
284 		 * = 3 - the sign string precedes the $currency_symbol
285 		 * = 4 - the sign string succeeds the $currency_symbol
286                  *
287 		 */
288 
289 		tmpptr = dst;
290 
291 		while (pad_size-- > 0)
292 			PRINT(' ');
293 
294 		if (sign_posn == 0 && (flags & IS_NEGATIVE))
295 			PRINT('(');
296 
297 		if (cs_precedes == 1) {
298 			if (sign_posn == 1 || sign_posn == 3) {
299 				PRINTS(signstr);
300 				if (sep_by_space == 2)		/* XXX: ? */
301 					PRINT(' ');
302 			}
303 
304 			if (!(flags & SUPRESS_CURR_SYMBOL)) {
305 				PRINTS(currency_symbol);
306 
307 				if (sign_posn == 4) {
308 					if (sep_by_space == 2)
309 						PRINT(space_char);
310 					PRINTS(signstr);
311 					if (sep_by_space == 1)
312 						PRINT(' ');
313 				} else if (sep_by_space == 1)
314 					PRINT(space_char);
315 			}
316 		} else if (sign_posn == 1)
317 			PRINTS(signstr);
318 
319 		PRINTS(asciivalue);
320 
321 		if (cs_precedes == 0) {
322 			if (sign_posn == 3) {
323 				if (sep_by_space == 1)
324 					PRINT(' ');
325 				PRINTS(signstr);
326 			}
327 
328 			if (!(flags & SUPRESS_CURR_SYMBOL)) {
329 				if ((sign_posn == 3 && sep_by_space == 2)
330 				    || (sep_by_space == 1
331 				    && (sign_posn == 0
332 				    || sign_posn == 1
333 				    || sign_posn == 2
334 				    || sign_posn == 4)))
335 					PRINT(space_char);
336 				PRINTS(currency_symbol); /* XXX: len */
337 				if (sign_posn == 4) {
338 					if (sep_by_space == 2)
339 						PRINT(' ');
340 					PRINTS(signstr);
341 				}
342 			}
343 		}
344 
345 		if (sign_posn == 2) {
346 			if (sep_by_space == 2)
347 				PRINT(' ');
348 			PRINTS(signstr);
349 		}
350 
351 		if (sign_posn == 0 && (flags & IS_NEGATIVE))
352 			PRINT(')');
353 
354 		if (dst - tmpptr < width) {
355 			if (flags & LEFT_JUSTIFY) {
356 				while (dst - tmpptr < width)
357 					PRINT(' ');
358 			} else {
359 				pad_size = dst-tmpptr;
360 				memmove(tmpptr + width-pad_size, tmpptr,
361 				    pad_size);
362 				memset(tmpptr, ' ', width-pad_size);
363 				dst += width-pad_size;
364 			}
365 		}
366 	}
367 
368 	PRINT('\0');
369 	va_end(ap);
370 	free(asciivalue);
371 	free(currency_symbol);
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 	sverrno = errno;
383 	if (asciivalue != NULL)
384 		free(asciivalue);
385 	if (currency_symbol != NULL)
386 		free(currency_symbol);
387 	errno = sverrno;
388 	va_end(ap);
389 	return (-1);
390 }
391 
392 static void
393 __setup_vars(int flags, char *cs_precedes, char *sep_by_space,
394 		char *sign_posn, char **signstr) {
395 
396 	struct lconv *lc = localeconv();
397 
398 	if ((flags & IS_NEGATIVE) && (flags & USE_INTL_CURRENCY)) {
399 		*cs_precedes = lc->int_n_cs_precedes;
400 		*sep_by_space = lc->int_n_sep_by_space;
401 		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->int_n_sign_posn;
402 		*signstr = (lc->negative_sign == '\0') ? "-"
403 		    : lc->negative_sign;
404 	} else if (flags & USE_INTL_CURRENCY) {
405 		*cs_precedes = lc->int_p_cs_precedes;
406 		*sep_by_space = lc->int_p_sep_by_space;
407 		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->int_p_sign_posn;
408 		*signstr = lc->positive_sign;
409 	} else if (flags & IS_NEGATIVE) {
410 		*cs_precedes = lc->n_cs_precedes;
411 		*sep_by_space = lc->n_sep_by_space;
412 		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->n_sign_posn;
413 		*signstr = (lc->negative_sign == '\0') ? "-"
414 		    : lc->negative_sign;
415 	} else {
416 		*cs_precedes = lc->p_cs_precedes;
417 		*sep_by_space = lc->p_sep_by_space;
418 		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->p_sign_posn;
419 		*signstr = lc->positive_sign;
420 	}
421 
422 	/* Set defult values for unspecified information. */
423 	if (*cs_precedes != 0)
424 		*cs_precedes = 1;
425 	if (*sep_by_space == CHAR_MAX)
426 		*sep_by_space = 0;
427 	if (*sign_posn == CHAR_MAX)
428 		*sign_posn = 0;
429 }
430 
431 static int
432 __calc_left_pad(int flags, char *cur_symb) {
433 
434 	char cs_precedes, sep_by_space, sign_posn, *signstr;
435 	int left_chars = 0;
436 
437 	__setup_vars(flags, &cs_precedes, &sep_by_space, &sign_posn, &signstr);
438 
439 	if (cs_precedes != 0) {
440 		left_chars += strlen(cur_symb);
441 		if (sep_by_space != 0)
442 			left_chars++;
443 	}
444 
445 	switch (sign_posn) {
446 		case 1:
447 			left_chars += strlen(signstr);
448 			break;
449 		case 3:
450 		case 4:
451 			if (cs_precedes != 0)
452 				left_chars += strlen(signstr);
453 	}
454 	return (left_chars);
455 }
456 
457 static int
458 get_groups(int size, char *grouping) {
459 
460 	int	chars = 0;
461 
462 	if (*grouping == CHAR_MAX || *grouping <= 0)	/* no grouping ? */
463 		return (0);
464 
465 	while (size > (int)*grouping) {
466 		chars++;
467 		size -= (int)*grouping++;
468 		/* no more grouping ? */
469 		if (*grouping == CHAR_MAX)
470 			break;
471 		/* rest grouping with same value ? */
472 		if (*grouping == 0) {
473 			chars += (size - 1) / *(grouping - 1);
474 			break;
475 		}
476 	}
477 	return (chars);
478 }
479 
480 /* convert double to ASCII */
481 static char *
482 __format_grouped_double(double value, int *flags,
483 			int left_prec, int right_prec, int pad_char) {
484 
485 	char		*rslt;
486 	char		*avalue;
487 	int		avalue_size;
488 	char		fmt[32];
489 
490 	size_t		bufsize;
491 	char		*bufend;
492 
493 	int		padded;
494 
495 	struct lconv	*lc = localeconv();
496 	char		*grouping;
497 	char		decimal_point;
498 	char		thousands_sep;
499 
500 	int groups = 0;
501 
502 	grouping = lc->mon_grouping;
503 	decimal_point = *lc->mon_decimal_point;
504 	if (decimal_point == '\0')
505 		decimal_point = *lc->decimal_point;
506 	thousands_sep = *lc->mon_thousands_sep;
507 	if (thousands_sep == '\0')
508 		thousands_sep = *lc->thousands_sep;
509 
510 	/* fill left_prec with default value */
511 	if (left_prec == -1)
512 		left_prec = 0;
513 
514 	/* fill right_prec with default value */
515 	if (right_prec == -1) {
516                 if (*flags & USE_INTL_CURRENCY)
517                         right_prec = lc->int_frac_digits;
518                 else
519                         right_prec = lc->frac_digits;
520 
521 		if (right_prec == CHAR_MAX)	/* POSIX locale ? */
522 			right_prec = 2;
523 	}
524 
525 	if (*flags & NEED_GROUPING)
526 		left_prec += get_groups(left_prec, grouping);
527 
528 	/* convert to string */
529 	snprintf(fmt, sizeof(fmt), "%%%d.%df", left_prec + right_prec + 1,
530 	    right_prec);
531 	avalue_size = asprintf(&avalue, fmt, value);
532 	if (avalue_size < 0)
533 		return (NULL);
534 
535 	/* make sure that we've enough space for result string */
536 	bufsize = strlen(avalue)*2+1;
537 	rslt = malloc(bufsize);
538 	if (rslt == NULL) {
539 		free(avalue);
540 		return (NULL);
541 	}
542 	memset(rslt, 0, bufsize);
543 	bufend = rslt + bufsize - 1;	/* reserve space for trailing '\0' */
544 
545 	/* skip spaces at beggining */
546 	padded = 0;
547 	while (avalue[padded] == ' ') {
548 		padded++;
549 		avalue_size--;
550 	}
551 
552 	if (right_prec > 0) {
553 		bufend -= right_prec;
554 		memcpy(bufend, avalue + avalue_size+padded-right_prec,
555 		    right_prec);
556 		*--bufend = decimal_point;
557 		avalue_size -= (right_prec + 1);
558 	}
559 
560 	if ((*flags & NEED_GROUPING) &&
561 	    thousands_sep != '\0' &&	/* XXX: need investigation */
562 	    *grouping != CHAR_MAX &&
563 	    *grouping > 0) {
564 		while (avalue_size > (int)*grouping) {
565 			GRPCPY(*grouping);
566 			GRPSEP;
567 			grouping++;
568 
569 			/* no more grouping ? */
570 			if (*grouping == CHAR_MAX)
571 				break;
572 
573 			/* rest grouping with same value ? */
574 			if (*grouping == 0) {
575 				grouping--;
576 				while (avalue_size > *grouping) {
577 					GRPCPY(*grouping);
578 					GRPSEP;
579 				}
580 			}
581 		}
582 		if (avalue_size != 0)
583 			GRPCPY(avalue_size);
584 		padded -= groups;
585 
586 	} else {
587 		bufend -= avalue_size;
588 		memcpy(bufend, avalue+padded, avalue_size);
589 		if (right_prec == 0)
590 			padded--;	/* decrease assumed $decimal_point */
591 	}
592 
593 	/* do padding with pad_char */
594 	if (padded > 0) {
595 		bufend -= padded;
596 		memset(bufend, pad_char, padded);
597 	}
598 
599 	bufsize = bufsize - (bufend - rslt) + 1;
600 	memmove(rslt, bufend, bufsize);
601 	free(avalue);
602 	return (rslt);
603 }
604