strfmon.c revision 83559 
1/*-
2 * Copyright (c) 2001 Alexey Zelkin
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#if defined(LIBC_RCS) && !defined(lint)
29static char rcsid[] = "$FreeBSD: head/lib/libc/stdlib/strfmon.c 83559 2001-09-17 00:23:19Z mike $";
30#endif
31
32#include <sys/types.h>
33#include <ctype.h>
34#include <errno.h>
35#include <limits.h>
36#include <locale.h>
37#if __STDC__
38#include <stdarg.h>
39#else
40#include <varargs.h>
41#endif
42#include <stdio.h>
43#include <stdlib.h>
44#include <string.h>
45
46/* internal flags */
47#define	NEED_GROUPING		0x01	/* print digits grouped (default) */
48#define	SIGN_POSN_USED		0x02	/* '+' or '(' usage flag */
49#define	LOCALE_POSN		0x04	/* use locale defined +/- (default) */
50#define	PARENTH_POSN		0x08	/* enclose negative amount in () */
51#define	SUPRESS_CURR_SYMBOL	0x10	/* supress the currency from output */
52#define	LEFT_JUSTIFY		0x20	/* left justify */
53#define	USE_INTL_CURRENCY	0x40	/* use international currency symbol */
54#define IS_NEGATIVE		0x80	/* is argument value negative ? */
55
56/* internal macros */
57#define PRINT(CH) do {						\
58	if (dst >= s + maxsize) 				\
59		goto e2big_error;				\
60	*dst++ = CH;						\
61} while (0)
62
63#define PRINTS(STR) do {					\
64	char *tmps = STR;					\
65	while (*tmps != '\0')					\
66		PRINT(*tmps++);					\
67} while (0)
68
69#define GET_NUMBER(VAR)	do {					\
70	VAR = 0;						\
71	while (isdigit((unsigned char)*fmt)) {			\
72		VAR *= 10;					\
73		VAR += *fmt - '0';				\
74		fmt++;						\
75	}							\
76} while (0)
77
78#define GRPCPY(howmany) do {					\
79	int i = howmany;					\
80	while (i-- > 0) {					\
81		avalue_size--;					\
82		*--bufend = *(avalue+avalue_size+padded);	\
83	}							\
84} while (0)
85
86#define GRPSEP do {						\
87	*--bufend = thousands_sep;				\
88	groups++;						\
89} while (0)
90
91static void __setup_vars(int, char *, char *, char *, char **);
92static int __calc_left_pad(int, char *);
93static char *__format_grouped_double(double, int *, int, int, int);
94
95#if __STDC__
96ssize_t
97strfmon(char *s, size_t maxsize, const char *format, ...)
98#else
99ssize_t
100strfmon(s, maxsize, format, va_alist)
101        char    *s;
102        size_t  maxsize;
103        const char *format;
104        va_dcl
105#endif
106{
107	va_list		ap;
108	char 		*dst;		/* output destination pointer */
109	const char 	*fmt;		/* current format poistion pointer */
110	struct lconv 	*lc;		/* pointer to lconv structure */
111	char		*asciivalue;	/* formatted double pointer */
112
113	int		flags;		/* formatting options */
114	int		pad_char;	/* padding character */
115	int		pad_size;	/* pad size */
116	int		width;		/* field width */
117	int		left_prec;	/* left precision */
118	int		right_prec;	/* right precision */
119	double		value;		/* just value */
120	char		space_char = ' '; /* space after currency */
121
122	char		cs_precedes,	/* values gathered from struct lconv */
123			sep_by_space,
124			sign_posn,
125			*signstr,
126			*currency_symbol;
127
128	char		*tmpptr;	/* temporary vars */
129	int		*ntmp;
130
131#if __STDC__
132        va_start(ap, format);
133#else
134        va_start(ap);
135#endif
136
137	lc = localeconv();
138	dst = s;
139	fmt = format;
140	asciivalue = NULL;
141	currency_symbol = NULL;
142	pad_size = 0;
143
144	while (*fmt) {
145		/* pass nonformating characters AS IS */
146		if (*fmt != '%')
147			goto literal;
148
149		/* '%' found ! */
150
151		/* "%%" mean just '%' */
152		if (*(fmt+1) == '%') {
153			fmt++;
154	literal:
155			PRINT(*fmt++);
156			continue;
157		}
158
159		/* set up initial values */
160		flags = (NEED_GROUPING|LOCALE_POSN);
161		pad_char = ' ';		/* padding character is "space" */
162		left_prec = -1;		/* no left precision specified */
163		right_prec = -1;	/* no right precision specified */
164		width = -1;		/* no width specified */
165		value = 0;		/* we have no value to print now */
166
167		/* Flags */
168		while (1) {
169			switch (*++fmt) {
170				case '=':	/* fill character */
171					pad_char = *++fmt;
172					if (pad_char == '\0')
173						goto format_error;
174					continue;
175				case '^':	/* not group currency  */
176					flags &= ~(NEED_GROUPING);
177					continue;
178				case '+':	/* use locale defined signs */
179					if (flags & SIGN_POSN_USED)
180						goto format_error;
181					flags |= (SIGN_POSN_USED|LOCALE_POSN);
182					continue;
183				case '(':	/* enclose negatives with () */
184					if (flags & SIGN_POSN_USED)
185						goto format_error;
186					flags |= (SIGN_POSN_USED|PARENTH_POSN);
187					continue;
188				case '!':	/* suppress currency symbol */
189					flags |= SUPRESS_CURR_SYMBOL;
190					continue;
191				case '-':	/* alignment (left)  */
192					flags |= LEFT_JUSTIFY;
193					continue;
194				case '#':	/* left || right precision */
195				case '.':
196					if (*fmt == '#')
197						ntmp = &left_prec;
198					else
199						ntmp = &right_prec;
200
201					if (!isdigit((unsigned char)*++fmt))
202						goto format_error;
203					GET_NUMBER(*ntmp);
204					fmt--;
205					continue;
206				default:
207					break;
208			}
209			break;
210		}
211
212		/* field Width */
213		if (isdigit((unsigned char)*fmt)) {
214			GET_NUMBER(width);
215			/* Do we have enough space to put number with
216			 * required width ?
217			 */
218			if (dst + width >= s + maxsize)
219				goto e2big_error;
220		}
221
222		/* Conversion Characters */
223		switch (*fmt++) {
224			case 'i':	/* use internaltion currency format */
225				flags |= USE_INTL_CURRENCY;
226				break;
227			case 'n':	/* use national currency format */
228				flags &= ~(USE_INTL_CURRENCY);
229				break;
230			default:	/* required character is missing or
231					   premature EOS */
232				goto format_error;
233		}
234
235		if (flags & USE_INTL_CURRENCY) {
236			currency_symbol = strdup(lc->int_curr_symbol);
237			if (currency_symbol != NULL)
238				space_char = *(currency_symbol+3);
239		} else
240			currency_symbol = strdup(lc->currency_symbol);
241
242		if (currency_symbol == NULL)
243			goto end_error;			/* ENOMEM. */
244
245		/* value itself */
246		value = va_arg(ap, double);
247
248		/* detect sign */
249		if (value < 0) {
250			flags |= IS_NEGATIVE;
251			value = -value;
252		}
253
254		/* fill left_prec with amount of padding chars */
255		if (left_prec >= 0) {
256			pad_size = __calc_left_pad((flags ^ IS_NEGATIVE),
257							currency_symbol) -
258				   __calc_left_pad(flags, currency_symbol);
259			if (pad_size < 0)
260				pad_size = 0;
261		}
262
263		asciivalue = __format_grouped_double(value, &flags,
264				left_prec, right_prec, pad_char);
265		if (asciivalue == NULL)
266			goto end_error;		/* errno already set     */
267						/* to ENOMEM by malloc() */
268
269		/* set some variables for later use */
270		__setup_vars(flags, &cs_precedes, &sep_by_space,
271				&sign_posn, &signstr);
272
273		/*
274		 * Description of some LC_MONETARY's values:
275		 *
276		 * p_cs_precedes & n_cs_precedes
277		 *
278		 * = 1 - $currency_symbol precedes the value
279		 *       for a monetary quantity with a non-negative value
280		 * = 0 - symbol succeeds the value
281		 *
282		 * p_sep_by_space & n_sep_by_space
283                 *
284		 * = 0 - no space separates $currency_symbol
285		 *       from the value for a monetary quantity with a
286		 *	 non-negative value
287		 * = 1 - space separates the symbol from the value
288		 * = 2 - space separates the symbol and the sign string,
289		 *       if adjacent.
290                 *
291		 * p_sign_posn & n_sign_posn
292                 *
293		 * = 0 - parentheses enclose the quantity and the
294		 *	 $currency_symbol
295		 * = 1 - the sign string precedes the quantity and the
296		 *       $currency_symbol
297		 * = 2 - the sign string succeeds the quantity and the
298		 *       $currency_symbol
299		 * = 3 - the sign string precedes the $currency_symbol
300		 * = 4 - the sign string succeeds the $currency_symbol
301                 *
302		 */
303
304		tmpptr = dst;
305
306		while (pad_size-- > 0)
307			PRINT(' ');
308
309		if (sign_posn == 0) {
310			if (flags & IS_NEGATIVE)
311				PRINT('(');
312			else
313				PRINT(' ');
314		}
315
316		if (cs_precedes == 1) {
317			if (sign_posn == 1 || sign_posn == 3) {
318				PRINTS(signstr);
319				if (sep_by_space == 2)		/* XXX: ? */
320					PRINT(' ');
321			}
322
323			if (!(flags & SUPRESS_CURR_SYMBOL)) {
324				PRINTS(currency_symbol);
325
326				if (sign_posn == 4) {
327					if (sep_by_space == 2)
328						PRINT(space_char);
329					PRINTS(signstr);
330					if (sep_by_space == 1)
331						PRINT(' ');
332				} else if (sep_by_space == 1)
333					PRINT(space_char);
334			}
335		} else if (sign_posn == 1)
336			PRINTS(signstr);
337
338		PRINTS(asciivalue);
339
340		if (cs_precedes == 0) {
341			if (sign_posn == 3) {
342				if (sep_by_space == 1)
343					PRINT(' ');
344				PRINTS(signstr);
345			}
346
347			if (!(flags & SUPRESS_CURR_SYMBOL)) {
348				if ((sign_posn == 3 && sep_by_space == 2)
349				    || (sep_by_space == 1
350				    && (sign_posn = 0
351				    || sign_posn == 1
352				    || sign_posn == 2
353				    || sign_posn == 4)))
354					PRINT(space_char);
355				PRINTS(currency_symbol); /* XXX: len */
356				if (sign_posn == 4) {
357					if (sep_by_space == 2)
358						PRINT(' ');
359					PRINTS(signstr);
360				}
361			}
362		}
363
364		if (sign_posn == 2) {
365			if (sep_by_space == 2)
366				PRINT(' ');
367			PRINTS(signstr);
368		}
369
370		if (sign_posn == 0 && (flags & IS_NEGATIVE))
371			PRINT(')');
372
373		if (dst - tmpptr < width) {
374			if (flags & LEFT_JUSTIFY) {
375				while (dst - tmpptr <= width)
376					PRINT(' ');
377			} else {
378				pad_size = dst-tmpptr;
379				memmove(tmpptr + width-pad_size, tmpptr,
380				    pad_size);
381				memset(tmpptr, ' ', width-pad_size);
382				dst += width-pad_size;
383			}
384		}
385	}
386
387	PRINT('\0');
388	va_end(ap);
389	return (dst - s - 1);	/* return size of put data except trailing '\0' */
390
391e2big_error:
392	errno = E2BIG;
393	goto end_error;
394
395format_error:
396	errno = EINVAL;
397
398end_error:
399	if (asciivalue != NULL)
400		free(asciivalue);
401	if (currency_symbol != NULL)
402		free(currency_symbol);
403	va_end(ap);
404	return (-1);
405}
406
407static void
408__setup_vars(int flags, char *cs_precedes, char *sep_by_space,
409		char *sign_posn, char **signstr) {
410
411	struct lconv *lc = localeconv();
412
413	if (flags & IS_NEGATIVE) {
414		*cs_precedes = lc->n_cs_precedes;
415		*sep_by_space = lc->n_sep_by_space;
416		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->n_sign_posn;
417		*signstr = (lc->negative_sign == '\0') ? "-"
418		    : lc->negative_sign;
419	} else {
420		*cs_precedes = lc->p_cs_precedes;
421		*sep_by_space = lc->p_sep_by_space;
422		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->p_sign_posn;
423		*signstr = lc->positive_sign;
424	}
425
426	/* Set defult values for unspecified information. */
427	if (*cs_precedes != 0)
428		*cs_precedes = 1;
429	if (*sep_by_space == CHAR_MAX)
430		*sep_by_space = 0;
431	if (*sign_posn == CHAR_MAX)
432		*sign_posn = 0;
433}
434
435static int
436__calc_left_pad(int flags, char *cur_symb) {
437
438	char cs_precedes, sep_by_space, sign_posn, *signstr;
439	int left_chars = 0;
440
441	__setup_vars(flags, &cs_precedes, &sep_by_space, &sign_posn, &signstr);
442
443	if (cs_precedes != 0) {
444		left_chars += strlen(cur_symb);
445		if (sep_by_space != 0)
446			left_chars++;
447	}
448
449	switch (sign_posn) {
450		case 1:
451			left_chars += strlen(signstr);
452			break;
453		case 3:
454		case 4:
455			if (cs_precedes != 0)
456				left_chars += strlen(signstr);
457	}
458	return (left_chars);
459}
460
461static int
462get_groups(int size, char *grouping) {
463
464	int	chars = 0;
465
466	if (*grouping == CHAR_MAX || *grouping <= 0)	/* no grouping ? */
467		return (0);
468
469	while (size > (int)*grouping) {
470		chars++;
471		size -= (int)*grouping++;
472		/* no more grouping ? */
473		if (*grouping == CHAR_MAX)
474			break;
475		/* rest grouping with same value ? */
476		if (*grouping == 0) {
477			chars += (size - 1) / *(grouping - 1);
478			break;
479		}
480	}
481	return (chars);
482}
483
484/* convert double to ASCII */
485static char *
486__format_grouped_double(double value, int *flags,
487			int left_prec, int right_prec, int pad_char) {
488
489	char		*rslt;
490	char		*avalue;
491	int		avalue_size;
492	char		fmt[32];
493
494	size_t		bufsize;
495	char		*bufend;
496
497	int		padded;
498
499	struct lconv	*lc = localeconv();
500	char		*grouping;
501	char		decimal_point;
502	char		thousands_sep;
503
504	int groups = 0;
505
506	grouping = lc->mon_grouping;
507	decimal_point = *lc->mon_decimal_point;
508	if (decimal_point == '\0') {
509		decimal_point = *lc->decimal_point;
510		if (decimal_point == '\0')
511			decimal_point = '.';
512	}
513	thousands_sep = *lc->mon_thousands_sep;
514	if (thousands_sep == '\0')
515		thousands_sep = *lc->thousands_sep;
516
517	/* fill left_prec with default value */
518	if (left_prec == -1)
519		left_prec = 0;
520
521	/* fill right_prec with default value */
522	if (right_prec == -1) {
523                if (*flags & USE_INTL_CURRENCY)
524                        right_prec = lc->int_frac_digits;
525                else
526                        right_prec = lc->frac_digits;
527
528		if (right_prec == CHAR_MAX)	/* POSIX locale ? */
529			right_prec = 2;
530	}
531
532	if (*flags & NEED_GROUPING)
533		left_prec += get_groups(left_prec, grouping);
534
535	/* convert to string */
536	snprintf(fmt, sizeof(fmt), "%%%d.%df", left_prec + right_prec + 1,
537	    right_prec);
538	avalue_size = asprintf(&avalue, fmt, value);
539	if (avalue_size < 0)
540		return (NULL);
541
542	/* make sure that we've enough space for result string */
543	bufsize = strlen(avalue)*2+1;
544	rslt = malloc(bufsize);
545	if (rslt == NULL) {
546		free(avalue);
547		return (NULL);
548	}
549	memset(rslt, 0, bufsize);
550	bufend = rslt + bufsize - 1;	/* reserve space for trailing '\0' */
551
552	/* skip spaces at beggining */
553	padded = 0;
554	while (avalue[padded] == ' ') {
555		padded++;
556		avalue_size--;
557	}
558
559	if (right_prec > 0) {
560		bufend -= right_prec;
561		memcpy(bufend, avalue + avalue_size+padded-right_prec,
562		    right_prec);
563		*--bufend = decimal_point;
564		avalue_size -= (right_prec + 1);
565	}
566
567	if ((*flags & NEED_GROUPING) &&
568	    thousands_sep != '\0' &&	/* XXX: need investigation */
569	    *grouping != CHAR_MAX &&
570	    *grouping > 0) {
571		while (avalue_size > (int)*grouping) {
572			GRPCPY(*grouping);
573			GRPSEP;
574			grouping++;
575
576			/* no more grouping ? */
577			if (*grouping == CHAR_MAX)
578				break;
579
580			/* rest grouping with same value ? */
581			if (*grouping == 0) {
582				grouping--;
583				while (avalue_size > *grouping) {
584					GRPCPY(*grouping);
585					GRPSEP;
586				}
587			}
588		}
589		if (avalue_size != 0)
590			GRPCPY(avalue_size);
591		padded -= groups;
592
593	} else {
594		bufend -= avalue_size;
595		memcpy(bufend, avalue+padded, avalue_size);
596		if (right_prec == 0)
597			padded--;	/* decrease assumed $decimal_point */
598	}
599
600	/* do padding with pad_char */
601	if (padded > 0) {
602		bufend -= padded;
603		memset(bufend, pad_char, padded);
604	}
605
606	bufsize = bufsize - (rslt - bufend);
607	memmove(rslt, bufend, bufsize);
608	free(avalue);
609	return (rslt);
610}
611