xref: /freebsd/lib/libc/stdlib/strfmon.c (revision 42c159fe388a3765f69860c84183700af37aca8a)
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 #if __STDC__
37 #include <stdarg.h>
38 #else
39 #include <varargs.h>
40 #endif
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 
45 /* internal flags */
46 #define	NEED_GROUPING		0x01	/* print digits grouped (default) */
47 #define	SIGN_POSN_USED		0x02	/* '+' or '(' usage flag */
48 #define	LOCALE_POSN		0x04	/* use locale defined +/- (default) */
49 #define	PARENTH_POSN		0x08	/* enclose negative amount in () */
50 #define	SUPRESS_CURR_SYMBOL	0x10	/* supress the currency from output */
51 #define	LEFT_JUSTIFY		0x20	/* left justify */
52 #define	USE_INTL_CURRENCY	0x40	/* use international currency symbol */
53 #define IS_NEGATIVE		0x80	/* is argument value negative ? */
54 
55 /* internal macros */
56 #define PRINT(CH) do {						\
57 	if (dst >= s + maxsize) 				\
58 		goto e2big_error;				\
59 	*dst++ = CH;						\
60 } while (0)
61 
62 #define PRINTS(STR) do {					\
63 	char *tmps = STR;					\
64 	while (*tmps != '\0')					\
65 		PRINT(*tmps++);					\
66 } while (0)
67 
68 #define GET_NUMBER(VAR)	do {					\
69 	VAR = 0;						\
70 	while (isdigit((unsigned char)*fmt)) {			\
71 		VAR *= 10;					\
72 		VAR += *fmt - '0';				\
73 		fmt++;						\
74 	}							\
75 } while (0)
76 
77 #define GRPCPY(howmany) do {					\
78 	int i = howmany;					\
79 	while (i-- > 0) {					\
80 		avalue_size--;					\
81 		*--bufend = *(avalue+avalue_size+padded);	\
82 	}							\
83 } while (0)
84 
85 #define GRPSEP do {						\
86 	*--bufend = thousands_sep;				\
87 	groups++;						\
88 } while (0)
89 
90 static void __setup_vars(int, char *, char *, char *, char **);
91 static int __calc_left_pad(int, char *);
92 static char *__format_grouped_double(double, int *, int, int, int);
93 
94 #if __STDC__
95 ssize_t
96 strfmon(char *s, size_t maxsize, const char *format, ...)
97 #else
98 ssize_t
99 strfmon(s, maxsize, format, va_alist)
100         char    *s;
101         size_t  maxsize;
102         const char *format;
103         va_dcl
104 #endif
105 {
106 	va_list		ap;
107 	char 		*dst;		/* output destination pointer */
108 	const char 	*fmt;		/* current format poistion pointer */
109 	struct lconv 	*lc;		/* pointer to lconv structure */
110 	char		*asciivalue;	/* formatted double pointer */
111 
112 	int		flags;		/* formatting options */
113 	int		pad_char;	/* padding character */
114 	int		pad_size;	/* pad size */
115 	int		width;		/* field width */
116 	int		left_prec;	/* left precision */
117 	int		right_prec;	/* right precision */
118 	double		value;		/* just value */
119 	char		space_char = ' '; /* space after currency */
120 
121 	char		cs_precedes,	/* values gathered from struct lconv */
122 			sep_by_space,
123 			sign_posn,
124 			*signstr,
125 			*currency_symbol;
126 
127 	char		*tmpptr;	/* temporary vars */
128 	int		*ntmp;
129 
130 #if __STDC__
131         va_start(ap, format);
132 #else
133         va_start(ap);
134 #endif
135 
136 	lc = localeconv();
137 	dst = s;
138 	fmt = format;
139 	asciivalue = NULL;
140 	currency_symbol = NULL;
141 	pad_size = 0;
142 
143 	while (*fmt) {
144 		/* pass nonformating characters AS IS */
145 		if (*fmt != '%')
146 			goto literal;
147 
148 		/* '%' found ! */
149 
150 		/* "%%" mean just '%' */
151 		if (*(fmt+1) == '%') {
152 			fmt++;
153 	literal:
154 			PRINT(*fmt++);
155 			continue;
156 		}
157 
158 		/* set up initial values */
159 		flags = (NEED_GROUPING|LOCALE_POSN);
160 		pad_char = ' ';		/* padding character is "space" */
161 		left_prec = -1;		/* no left precision specified */
162 		right_prec = -1;	/* no right precision specified */
163 		width = -1;		/* no width specified */
164 		value = 0;		/* we have no value to print now */
165 
166 		/* Flags */
167 		while (1) {
168 			switch (*++fmt) {
169 				case '=':	/* fill character */
170 					pad_char = *++fmt;
171 					if (pad_char == '\0')
172 						goto format_error;
173 					continue;
174 				case '^':	/* not group currency  */
175 					flags &= ~(NEED_GROUPING);
176 					continue;
177 				case '+':	/* use locale defined signs */
178 					if (flags & SIGN_POSN_USED)
179 						goto format_error;
180 					flags |= (SIGN_POSN_USED|LOCALE_POSN);
181 					continue;
182 				case '(':	/* enclose negatives with () */
183 					if (flags & SIGN_POSN_USED)
184 						goto format_error;
185 					flags |= (SIGN_POSN_USED|PARENTH_POSN);
186 					continue;
187 				case '!':	/* suppress currency symbol */
188 					flags |= SUPRESS_CURR_SYMBOL;
189 					continue;
190 				case '-':	/* alignment (left)  */
191 					flags |= LEFT_JUSTIFY;
192 					continue;
193 				case '#':	/* left || right precision */
194 				case '.':
195 					if (*fmt == '#')
196 						ntmp = &left_prec;
197 					else
198 						ntmp = &right_prec;
199 
200 					if (!isdigit((unsigned char)*++fmt))
201 						goto format_error;
202 					GET_NUMBER(*ntmp);
203 					fmt--;
204 					continue;
205 				default:
206 					break;
207 			}
208 			break;
209 		}
210 
211 		/* field Width */
212 		if (isdigit((unsigned char)*fmt)) {
213 			GET_NUMBER(width);
214 			/* Do we have enough space to put number with
215 			 * required width ?
216 			 */
217 			if (dst + width >= s + maxsize)
218 				goto e2big_error;
219 		}
220 
221 		/* Conversion Characters */
222 		switch (*fmt++) {
223 			case 'i':	/* use internaltion currency format */
224 				flags |= USE_INTL_CURRENCY;
225 				break;
226 			case 'n':	/* use national currency format */
227 				flags &= ~(USE_INTL_CURRENCY);
228 				break;
229 			default:	/* required character is missing or
230 					   premature EOS */
231 				goto format_error;
232 		}
233 
234 		if (flags & USE_INTL_CURRENCY) {
235 			currency_symbol = strdup(lc->int_curr_symbol);
236 			if (currency_symbol != NULL)
237 				space_char = *(currency_symbol+3);
238 		} else
239 			currency_symbol = strdup(lc->currency_symbol);
240 
241 		if (currency_symbol == NULL)
242 			goto end_error;			/* ENOMEM. */
243 
244 		/* value itself */
245 		value = va_arg(ap, double);
246 
247 		/* detect sign */
248 		if (value < 0) {
249 			flags |= IS_NEGATIVE;
250 			value = -value;
251 		}
252 
253 		/* fill left_prec with amount of padding chars */
254 		if (left_prec >= 0) {
255 			pad_size = __calc_left_pad((flags ^ IS_NEGATIVE),
256 							currency_symbol) -
257 				   __calc_left_pad(flags, currency_symbol);
258 			if (pad_size < 0)
259 				pad_size = 0;
260 		}
261 
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) {
309 			if (flags & IS_NEGATIVE)
310 				PRINT('(');
311 			else
312 				PRINT(' ');
313 		}
314 
315 		if (cs_precedes == 1) {
316 			if (sign_posn == 1 || sign_posn == 3) {
317 				PRINTS(signstr);
318 				if (sep_by_space == 2)		/* XXX: ? */
319 					PRINT(' ');
320 			}
321 
322 			if (!(flags & SUPRESS_CURR_SYMBOL)) {
323 				PRINTS(currency_symbol);
324 
325 				if (sign_posn == 4) {
326 					if (sep_by_space == 2)
327 						PRINT(space_char);
328 					PRINTS(signstr);
329 					if (sep_by_space == 1)
330 						PRINT(' ');
331 				} else if (sep_by_space == 1)
332 					PRINT(space_char);
333 			}
334 		} else if (sign_posn == 1)
335 			PRINTS(signstr);
336 
337 		PRINTS(asciivalue);
338 
339 		if (cs_precedes == 0) {
340 			if (sign_posn == 3) {
341 				if (sep_by_space == 1)
342 					PRINT(' ');
343 				PRINTS(signstr);
344 			}
345 
346 			if (!(flags & SUPRESS_CURR_SYMBOL)) {
347 				if ((sign_posn == 3 && sep_by_space == 2)
348 				    || (sep_by_space == 1
349 				    && (sign_posn = 0
350 				    || sign_posn == 1
351 				    || sign_posn == 2
352 				    || sign_posn == 4)))
353 					PRINT(space_char);
354 				PRINTS(currency_symbol); /* XXX: len */
355 				if (sign_posn == 4) {
356 					if (sep_by_space == 2)
357 						PRINT(' ');
358 					PRINTS(signstr);
359 				}
360 			}
361 		}
362 
363 		if (sign_posn == 2) {
364 			if (sep_by_space == 2)
365 				PRINT(' ');
366 			PRINTS(signstr);
367 		}
368 
369 		if (sign_posn == 0 && (flags & IS_NEGATIVE))
370 			PRINT(')');
371 
372 		if (dst - tmpptr < width) {
373 			if (flags & LEFT_JUSTIFY) {
374 				while (dst - tmpptr <= width)
375 					PRINT(' ');
376 			} else {
377 				pad_size = dst-tmpptr;
378 				memmove(tmpptr + width-pad_size, tmpptr,
379 				    pad_size);
380 				memset(tmpptr, ' ', width-pad_size);
381 				dst += width-pad_size;
382 			}
383 		}
384 	}
385 
386 	PRINT('\0');
387 	va_end(ap);
388 	return (dst - s - 1);	/* return size of put data except trailing '\0' */
389 
390 e2big_error:
391 	errno = E2BIG;
392 	goto end_error;
393 
394 format_error:
395 	errno = EINVAL;
396 
397 end_error:
398 	if (asciivalue != NULL)
399 		free(asciivalue);
400 	if (currency_symbol != NULL)
401 		free(currency_symbol);
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) {
413 		*cs_precedes = lc->n_cs_precedes;
414 		*sep_by_space = lc->n_sep_by_space;
415 		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->n_sign_posn;
416 		*signstr = (lc->negative_sign == '\0') ? "-"
417 		    : lc->negative_sign;
418 	} else {
419 		*cs_precedes = lc->p_cs_precedes;
420 		*sep_by_space = lc->p_sep_by_space;
421 		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->p_sign_posn;
422 		*signstr = lc->positive_sign;
423 	}
424 
425 	/* Set defult values for unspecified information. */
426 	if (*cs_precedes != 0)
427 		*cs_precedes = 1;
428 	if (*sep_by_space == CHAR_MAX)
429 		*sep_by_space = 0;
430 	if (*sign_posn == CHAR_MAX)
431 		*sign_posn = 0;
432 }
433 
434 static int
435 __calc_left_pad(int flags, char *cur_symb) {
436 
437 	char cs_precedes, sep_by_space, sign_posn, *signstr;
438 	int left_chars = 0;
439 
440 	__setup_vars(flags, &cs_precedes, &sep_by_space, &sign_posn, &signstr);
441 
442 	if (cs_precedes != 0) {
443 		left_chars += strlen(cur_symb);
444 		if (sep_by_space != 0)
445 			left_chars++;
446 	}
447 
448 	switch (sign_posn) {
449 		case 1:
450 			left_chars += strlen(signstr);
451 			break;
452 		case 3:
453 		case 4:
454 			if (cs_precedes != 0)
455 				left_chars += strlen(signstr);
456 	}
457 	return (left_chars);
458 }
459 
460 static int
461 get_groups(int size, char *grouping) {
462 
463 	int	chars = 0;
464 
465 	if (*grouping == CHAR_MAX || *grouping <= 0)	/* no grouping ? */
466 		return (0);
467 
468 	while (size > (int)*grouping) {
469 		chars++;
470 		size -= (int)*grouping++;
471 		/* no more grouping ? */
472 		if (*grouping == CHAR_MAX)
473 			break;
474 		/* rest grouping with same value ? */
475 		if (*grouping == 0) {
476 			chars += (size - 1) / *(grouping - 1);
477 			break;
478 		}
479 	}
480 	return (chars);
481 }
482 
483 /* convert double to ASCII */
484 static char *
485 __format_grouped_double(double value, int *flags,
486 			int left_prec, int right_prec, int pad_char) {
487 
488 	char		*rslt;
489 	char		*avalue;
490 	int		avalue_size;
491 	char		fmt[32];
492 
493 	size_t		bufsize;
494 	char		*bufend;
495 
496 	int		padded;
497 
498 	struct lconv	*lc = localeconv();
499 	char		*grouping;
500 	char		decimal_point;
501 	char		thousands_sep;
502 
503 	int groups = 0;
504 
505 	grouping = lc->mon_grouping;
506 	decimal_point = *lc->mon_decimal_point;
507 	if (decimal_point == '\0') {
508 		decimal_point = *lc->decimal_point;
509 		if (decimal_point == '\0')
510 			decimal_point = '.';
511 	}
512 	thousands_sep = *lc->mon_thousands_sep;
513 	if (thousands_sep == '\0')
514 		thousands_sep = *lc->thousands_sep;
515 
516 	/* fill left_prec with default value */
517 	if (left_prec == -1)
518 		left_prec = 0;
519 
520 	/* fill right_prec with default value */
521 	if (right_prec == -1) {
522                 if (*flags & USE_INTL_CURRENCY)
523                         right_prec = lc->int_frac_digits;
524                 else
525                         right_prec = lc->frac_digits;
526 
527 		if (right_prec == CHAR_MAX)	/* POSIX locale ? */
528 			right_prec = 2;
529 	}
530 
531 	if (*flags & NEED_GROUPING)
532 		left_prec += get_groups(left_prec, grouping);
533 
534 	/* convert to string */
535 	snprintf(fmt, sizeof(fmt), "%%%d.%df", left_prec + right_prec + 1,
536 	    right_prec);
537 	avalue_size = asprintf(&avalue, fmt, value);
538 	if (avalue_size < 0)
539 		return (NULL);
540 
541 	/* make sure that we've enough space for result string */
542 	bufsize = strlen(avalue)*2+1;
543 	rslt = malloc(bufsize);
544 	if (rslt == NULL) {
545 		free(avalue);
546 		return (NULL);
547 	}
548 	memset(rslt, 0, bufsize);
549 	bufend = rslt + bufsize - 1;	/* reserve space for trailing '\0' */
550 
551 	/* skip spaces at beggining */
552 	padded = 0;
553 	while (avalue[padded] == ' ') {
554 		padded++;
555 		avalue_size--;
556 	}
557 
558 	if (right_prec > 0) {
559 		bufend -= right_prec;
560 		memcpy(bufend, avalue + avalue_size+padded-right_prec,
561 		    right_prec);
562 		*--bufend = decimal_point;
563 		avalue_size -= (right_prec + 1);
564 	}
565 
566 	if ((*flags & NEED_GROUPING) &&
567 	    thousands_sep != '\0' &&	/* XXX: need investigation */
568 	    *grouping != CHAR_MAX &&
569 	    *grouping > 0) {
570 		while (avalue_size > (int)*grouping) {
571 			GRPCPY(*grouping);
572 			GRPSEP;
573 			grouping++;
574 
575 			/* no more grouping ? */
576 			if (*grouping == CHAR_MAX)
577 				break;
578 
579 			/* rest grouping with same value ? */
580 			if (*grouping == 0) {
581 				grouping--;
582 				while (avalue_size > *grouping) {
583 					GRPCPY(*grouping);
584 					GRPSEP;
585 				}
586 			}
587 		}
588 		if (avalue_size != 0)
589 			GRPCPY(avalue_size);
590 		padded -= groups;
591 
592 	} else {
593 		bufend -= avalue_size;
594 		memcpy(bufend, avalue+padded, avalue_size);
595 		if (right_prec == 0)
596 			padded--;	/* decrease assumed $decimal_point */
597 	}
598 
599 	/* do padding with pad_char */
600 	if (padded > 0) {
601 		bufend -= padded;
602 		memset(bufend, pad_char, padded);
603 	}
604 
605 	bufsize = bufsize - (rslt - bufend);
606 	memmove(rslt, bufend, bufsize);
607 	free(avalue);
608 	return (rslt);
609 }
610