strfmon.c revision 104946 
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: head/lib/libc/stdlib/strfmon.c 104946 2002-10-11 23:31:50Z tjr $");
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
86static void __setup_vars(int, char *, char *, char *, char **);
87static int __calc_left_pad(int, char *);
88static char *__format_grouped_double(double, int *, int, int, int);
89
90ssize_t
91strfmon(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	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	return (dst - s - 1);	/* return size of put data except trailing '\0' */
372
373e2big_error:
374	errno = E2BIG;
375	goto end_error;
376
377format_error:
378	errno = EINVAL;
379
380end_error:
381	sverrno = errno;
382	if (asciivalue != NULL)
383		free(asciivalue);
384	if (currency_symbol != NULL)
385		free(currency_symbol);
386	errno = sverrno;
387	va_end(ap);
388	return (-1);
389}
390
391static void
392__setup_vars(int flags, char *cs_precedes, char *sep_by_space,
393		char *sign_posn, char **signstr) {
394
395	struct lconv *lc = localeconv();
396
397	if ((flags & IS_NEGATIVE) && (flags & USE_INTL_CURRENCY)) {
398		*cs_precedes = lc->int_n_cs_precedes;
399		*sep_by_space = lc->int_n_sep_by_space;
400		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->int_n_sign_posn;
401		*signstr = (lc->negative_sign == '\0') ? "-"
402		    : lc->negative_sign;
403	} else if (flags & USE_INTL_CURRENCY) {
404		*cs_precedes = lc->int_p_cs_precedes;
405		*sep_by_space = lc->int_p_sep_by_space;
406		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->int_p_sign_posn;
407		*signstr = lc->positive_sign;
408	} else if (flags & IS_NEGATIVE) {
409		*cs_precedes = lc->n_cs_precedes;
410		*sep_by_space = lc->n_sep_by_space;
411		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->n_sign_posn;
412		*signstr = (lc->negative_sign == '\0') ? "-"
413		    : lc->negative_sign;
414	} else {
415		*cs_precedes = lc->p_cs_precedes;
416		*sep_by_space = lc->p_sep_by_space;
417		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->p_sign_posn;
418		*signstr = lc->positive_sign;
419	}
420
421	/* Set defult values for unspecified information. */
422	if (*cs_precedes != 0)
423		*cs_precedes = 1;
424	if (*sep_by_space == CHAR_MAX)
425		*sep_by_space = 0;
426	if (*sign_posn == CHAR_MAX)
427		*sign_posn = 0;
428}
429
430static int
431__calc_left_pad(int flags, char *cur_symb) {
432
433	char cs_precedes, sep_by_space, sign_posn, *signstr;
434	int left_chars = 0;
435
436	__setup_vars(flags, &cs_precedes, &sep_by_space, &sign_posn, &signstr);
437
438	if (cs_precedes != 0) {
439		left_chars += strlen(cur_symb);
440		if (sep_by_space != 0)
441			left_chars++;
442	}
443
444	switch (sign_posn) {
445		case 1:
446			left_chars += strlen(signstr);
447			break;
448		case 3:
449		case 4:
450			if (cs_precedes != 0)
451				left_chars += strlen(signstr);
452	}
453	return (left_chars);
454}
455
456static int
457get_groups(int size, char *grouping) {
458
459	int	chars = 0;
460
461	if (*grouping == CHAR_MAX || *grouping <= 0)	/* no grouping ? */
462		return (0);
463
464	while (size > (int)*grouping) {
465		chars++;
466		size -= (int)*grouping++;
467		/* no more grouping ? */
468		if (*grouping == CHAR_MAX)
469			break;
470		/* rest grouping with same value ? */
471		if (*grouping == 0) {
472			chars += (size - 1) / *(grouping - 1);
473			break;
474		}
475	}
476	return (chars);
477}
478
479/* convert double to ASCII */
480static char *
481__format_grouped_double(double value, int *flags,
482			int left_prec, int right_prec, int pad_char) {
483
484	char		*rslt;
485	char		*avalue;
486	int		avalue_size;
487	char		fmt[32];
488
489	size_t		bufsize;
490	char		*bufend;
491
492	int		padded;
493
494	struct lconv	*lc = localeconv();
495	char		*grouping;
496	char		decimal_point;
497	char		thousands_sep;
498
499	int groups = 0;
500
501	grouping = lc->mon_grouping;
502	decimal_point = *lc->mon_decimal_point;
503	if (decimal_point == '\0') {
504		decimal_point = *lc->decimal_point;
505		if (decimal_point == '\0')
506			decimal_point = '.';
507	}
508	thousands_sep = *lc->mon_thousands_sep;
509	if (thousands_sep == '\0')
510		thousands_sep = *lc->thousands_sep;
511
512	/* fill left_prec with default value */
513	if (left_prec == -1)
514		left_prec = 0;
515
516	/* fill right_prec with default value */
517	if (right_prec == -1) {
518                if (*flags & USE_INTL_CURRENCY)
519                        right_prec = lc->int_frac_digits;
520                else
521                        right_prec = lc->frac_digits;
522
523		if (right_prec == CHAR_MAX)	/* POSIX locale ? */
524			right_prec = 2;
525	}
526
527	if (*flags & NEED_GROUPING)
528		left_prec += get_groups(left_prec, grouping);
529
530	/* convert to string */
531	snprintf(fmt, sizeof(fmt), "%%%d.%df", left_prec + right_prec + 1,
532	    right_prec);
533	avalue_size = asprintf(&avalue, fmt, value);
534	if (avalue_size < 0)
535		return (NULL);
536
537	/* make sure that we've enough space for result string */
538	bufsize = strlen(avalue)*2+1;
539	rslt = malloc(bufsize);
540	if (rslt == NULL) {
541		free(avalue);
542		return (NULL);
543	}
544	memset(rslt, 0, bufsize);
545	bufend = rslt + bufsize - 1;	/* reserve space for trailing '\0' */
546
547	/* skip spaces at beggining */
548	padded = 0;
549	while (avalue[padded] == ' ') {
550		padded++;
551		avalue_size--;
552	}
553
554	if (right_prec > 0) {
555		bufend -= right_prec;
556		memcpy(bufend, avalue + avalue_size+padded-right_prec,
557		    right_prec);
558		*--bufend = decimal_point;
559		avalue_size -= (right_prec + 1);
560	}
561
562	if ((*flags & NEED_GROUPING) &&
563	    thousands_sep != '\0' &&	/* XXX: need investigation */
564	    *grouping != CHAR_MAX &&
565	    *grouping > 0) {
566		while (avalue_size > (int)*grouping) {
567			GRPCPY(*grouping);
568			GRPSEP;
569			grouping++;
570
571			/* no more grouping ? */
572			if (*grouping == CHAR_MAX)
573				break;
574
575			/* rest grouping with same value ? */
576			if (*grouping == 0) {
577				grouping--;
578				while (avalue_size > *grouping) {
579					GRPCPY(*grouping);
580					GRPSEP;
581				}
582			}
583		}
584		if (avalue_size != 0)
585			GRPCPY(avalue_size);
586		padded -= groups;
587
588	} else {
589		bufend -= avalue_size;
590		memcpy(bufend, avalue+padded, avalue_size);
591		if (right_prec == 0)
592			padded--;	/* decrease assumed $decimal_point */
593	}
594
595	/* do padding with pad_char */
596	if (padded > 0) {
597		bufend -= padded;
598		memset(bufend, pad_char, padded);
599	}
600
601	bufsize = bufsize - (rslt - bufend);
602	memmove(rslt, bufend, bufsize);
603	free(avalue);
604	return (rslt);
605}
606