strfmon.c revision 104944 
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 104944 2002-10-11 23:08:03Z 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
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	return (dst - s - 1);	/* return size of put data except trailing '\0' */
371
372e2big_error:
373	errno = E2BIG;
374	goto end_error;
375
376format_error:
377	errno = EINVAL;
378
379end_error:
380	if (asciivalue != NULL)
381		free(asciivalue);
382	if (currency_symbol != NULL)
383		free(currency_symbol);
384	va_end(ap);
385	return (-1);
386}
387
388static void
389__setup_vars(int flags, char *cs_precedes, char *sep_by_space,
390		char *sign_posn, char **signstr) {
391
392	struct lconv *lc = localeconv();
393
394	if ((flags & IS_NEGATIVE) && (flags & USE_INTL_CURRENCY)) {
395		*cs_precedes = lc->int_n_cs_precedes;
396		*sep_by_space = lc->int_n_sep_by_space;
397		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->int_n_sign_posn;
398		*signstr = (lc->negative_sign == '\0') ? "-"
399		    : lc->negative_sign;
400	} else if (flags & USE_INTL_CURRENCY) {
401		*cs_precedes = lc->int_p_cs_precedes;
402		*sep_by_space = lc->int_p_sep_by_space;
403		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->int_p_sign_posn;
404		*signstr = lc->positive_sign;
405	} else if (flags & IS_NEGATIVE) {
406		*cs_precedes = lc->n_cs_precedes;
407		*sep_by_space = lc->n_sep_by_space;
408		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->n_sign_posn;
409		*signstr = (lc->negative_sign == '\0') ? "-"
410		    : lc->negative_sign;
411	} else {
412		*cs_precedes = lc->p_cs_precedes;
413		*sep_by_space = lc->p_sep_by_space;
414		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->p_sign_posn;
415		*signstr = lc->positive_sign;
416	}
417
418	/* Set defult values for unspecified information. */
419	if (*cs_precedes != 0)
420		*cs_precedes = 1;
421	if (*sep_by_space == CHAR_MAX)
422		*sep_by_space = 0;
423	if (*sign_posn == CHAR_MAX)
424		*sign_posn = 0;
425}
426
427static int
428__calc_left_pad(int flags, char *cur_symb) {
429
430	char cs_precedes, sep_by_space, sign_posn, *signstr;
431	int left_chars = 0;
432
433	__setup_vars(flags, &cs_precedes, &sep_by_space, &sign_posn, &signstr);
434
435	if (cs_precedes != 0) {
436		left_chars += strlen(cur_symb);
437		if (sep_by_space != 0)
438			left_chars++;
439	}
440
441	switch (sign_posn) {
442		case 1:
443			left_chars += strlen(signstr);
444			break;
445		case 3:
446		case 4:
447			if (cs_precedes != 0)
448				left_chars += strlen(signstr);
449	}
450	return (left_chars);
451}
452
453static int
454get_groups(int size, char *grouping) {
455
456	int	chars = 0;
457
458	if (*grouping == CHAR_MAX || *grouping <= 0)	/* no grouping ? */
459		return (0);
460
461	while (size > (int)*grouping) {
462		chars++;
463		size -= (int)*grouping++;
464		/* no more grouping ? */
465		if (*grouping == CHAR_MAX)
466			break;
467		/* rest grouping with same value ? */
468		if (*grouping == 0) {
469			chars += (size - 1) / *(grouping - 1);
470			break;
471		}
472	}
473	return (chars);
474}
475
476/* convert double to ASCII */
477static char *
478__format_grouped_double(double value, int *flags,
479			int left_prec, int right_prec, int pad_char) {
480
481	char		*rslt;
482	char		*avalue;
483	int		avalue_size;
484	char		fmt[32];
485
486	size_t		bufsize;
487	char		*bufend;
488
489	int		padded;
490
491	struct lconv	*lc = localeconv();
492	char		*grouping;
493	char		decimal_point;
494	char		thousands_sep;
495
496	int groups = 0;
497
498	grouping = lc->mon_grouping;
499	decimal_point = *lc->mon_decimal_point;
500	if (decimal_point == '\0') {
501		decimal_point = *lc->decimal_point;
502		if (decimal_point == '\0')
503			decimal_point = '.';
504	}
505	thousands_sep = *lc->mon_thousands_sep;
506	if (thousands_sep == '\0')
507		thousands_sep = *lc->thousands_sep;
508
509	/* fill left_prec with default value */
510	if (left_prec == -1)
511		left_prec = 0;
512
513	/* fill right_prec with default value */
514	if (right_prec == -1) {
515                if (*flags & USE_INTL_CURRENCY)
516                        right_prec = lc->int_frac_digits;
517                else
518                        right_prec = lc->frac_digits;
519
520		if (right_prec == CHAR_MAX)	/* POSIX locale ? */
521			right_prec = 2;
522	}
523
524	if (*flags & NEED_GROUPING)
525		left_prec += get_groups(left_prec, grouping);
526
527	/* convert to string */
528	snprintf(fmt, sizeof(fmt), "%%%d.%df", left_prec + right_prec + 1,
529	    right_prec);
530	avalue_size = asprintf(&avalue, fmt, value);
531	if (avalue_size < 0)
532		return (NULL);
533
534	/* make sure that we've enough space for result string */
535	bufsize = strlen(avalue)*2+1;
536	rslt = malloc(bufsize);
537	if (rslt == NULL) {
538		free(avalue);
539		return (NULL);
540	}
541	memset(rslt, 0, bufsize);
542	bufend = rslt + bufsize - 1;	/* reserve space for trailing '\0' */
543
544	/* skip spaces at beggining */
545	padded = 0;
546	while (avalue[padded] == ' ') {
547		padded++;
548		avalue_size--;
549	}
550
551	if (right_prec > 0) {
552		bufend -= right_prec;
553		memcpy(bufend, avalue + avalue_size+padded-right_prec,
554		    right_prec);
555		*--bufend = decimal_point;
556		avalue_size -= (right_prec + 1);
557	}
558
559	if ((*flags & NEED_GROUPING) &&
560	    thousands_sep != '\0' &&	/* XXX: need investigation */
561	    *grouping != CHAR_MAX &&
562	    *grouping > 0) {
563		while (avalue_size > (int)*grouping) {
564			GRPCPY(*grouping);
565			GRPSEP;
566			grouping++;
567
568			/* no more grouping ? */
569			if (*grouping == CHAR_MAX)
570				break;
571
572			/* rest grouping with same value ? */
573			if (*grouping == 0) {
574				grouping--;
575				while (avalue_size > *grouping) {
576					GRPCPY(*grouping);
577					GRPSEP;
578				}
579			}
580		}
581		if (avalue_size != 0)
582			GRPCPY(avalue_size);
583		padded -= groups;
584
585	} else {
586		bufend -= avalue_size;
587		memcpy(bufend, avalue+padded, avalue_size);
588		if (right_prec == 0)
589			padded--;	/* decrease assumed $decimal_point */
590	}
591
592	/* do padding with pad_char */
593	if (padded > 0) {
594		bufend -= padded;
595		memset(bufend, pad_char, padded);
596	}
597
598	bufsize = bufsize - (rslt - bufend);
599	memmove(rslt, bufend, bufsize);
600	free(avalue);
601	return (rslt);
602}
603