1/*	$OpenBSD: number.c,v 1.20 2016/03/07 12:07:56 mestre Exp $	*/
2
3/*
4 * Copyright (c) 1988, 1993, 1994
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <ctype.h>
33#include <err.h>
34#include <stdio.h>
35#include <stdlib.h>
36#include <string.h>
37#include <unistd.h>
38
39#define	MAXNUM		65		/* Biggest number we handle. */
40#define	LINELEN		256
41
42static const char	*const name1[] = {
43	"",		"one",		"two",		"three",
44	"four",		"five",		"six",		"seven",
45	"eight",	"nine",		"ten",		"eleven",
46	"twelve",	"thirteen",	"fourteen",	"fifteen",
47	"sixteen",	"seventeen",	"eighteen",	"nineteen",
48},
49		*const name2[] = {
50	"",		"ten",		"twenty",	"thirty",
51	"forty",	"fifty",	"sixty",	"seventy",
52	"eighty",	"ninety",
53},
54		*const name3[] = {
55	"hundred",	"thousand",	"million",	"billion",
56	"trillion",	"quadrillion",	"quintillion",	"sextillion",
57	"septillion",	"octillion",	"nonillion",	"decillion",
58	"undecillion",	"duodecillion",	"tredecillion",	"quattuordecillion",
59	"quindecillion",		"sexdecillion",
60	"septendecillion",		"octodecillion",
61	"novemdecillion",		"vigintillion",
62};
63
64void	convert(char *);
65void	convertexp(char *);
66int	number(const char *, int);
67void	pfract(int);
68int	unit(int, const char *);
69__dead void	usage(void);
70
71int lflag;
72
73int
74main(int argc, char *argv[])
75{
76	int ch, first;
77	char line[LINELEN];
78
79	if (pledge("stdio", NULL) == -1)
80		err(1, "pledge");
81
82	lflag = 0;
83	while ((ch = getopt(argc, argv, "hl")) != -1)
84		switch (ch) {
85		case 'l':
86			lflag = 1;
87			break;
88		case 'h':
89		default:
90			usage();
91		}
92	argc -= optind;
93	argv += optind;
94
95	if (*argv == NULL)
96		for (first = 1;
97		    fgets(line, sizeof(line), stdin) != NULL; first = 0) {
98			if (strchr(line, '\n') == NULL)
99				errx(1, "line too long.");
100			if (!first)
101				(void)printf("...\n");
102			convert(line);
103			if (lflag)
104				(void)printf("\n");
105		}
106	else
107		for (first = 1; *argv != NULL; first = 0, ++argv) {
108			if (!first)
109				(void)printf("...\n");
110			convert(*argv);
111			if (lflag)
112				(void)printf("\n");
113		}
114	return 0;
115}
116
117void
118convert(char *line)
119{
120	int flen, len, rval;
121	char *p, *fraction;
122
123	/* strip trailing and leading whitespace */
124	len = strlen(line) - 1;
125	while ((isblank((unsigned char)line[len])) || (line[len] == '\n'))
126		line[len--] = '\0';
127	while ((isblank((unsigned char)line[0])) || (line[0] == '\n'))
128		line++;
129	if (strchr(line, 'e') || strchr(line, 'E'))
130		convertexp(line);
131	else {
132	fraction = NULL;
133	for (p = line; *p != '\0' && *p != '\n'; ++p) {
134		if (isblank((unsigned char)*p))
135			goto badnum;
136		if (isdigit((unsigned char)*p))
137			continue;
138		switch (*p) {
139		case '.':
140			if (fraction != NULL)
141				goto badnum;
142			fraction = p + 1;
143			*p = '\0';
144			break;
145		case '-':
146		case '+':
147			if (p == line)
148				break;
149			/* FALLTHROUGH */
150		default:
151badnum:			errx(1, "illegal number: %s", line);
152			break;
153		}
154	}
155	*p = '\0';
156
157	if ((len = strlen(line)) > MAXNUM ||
158	    ((fraction != NULL) && (flen = strlen(fraction)) > MAXNUM))
159		errx(1, "number too long (max %d digits).", MAXNUM);
160
161	if (*line == '-') {
162		(void)printf("minus%s", lflag ? " " : "\n");
163		++line;
164		--len;
165	}
166	if (*line == '+') {
167		(void)printf("plus%s", lflag ? " " : "\n");
168		++line;
169		--len;
170	}
171
172	rval = len > 0 ? unit(len, line) : 0;
173	if (fraction != NULL && flen != 0)
174		for (p = fraction; *p != '\0'; ++p)
175			if (*p != '0') {
176				if (rval)
177					(void)printf("%sand%s",
178					    lflag ? " " : "",
179					    lflag ? " " : "\n");
180				if (unit(flen, fraction)) {
181					if (lflag)
182						(void)printf(" ");
183					pfract(flen);
184					rval = 1;
185				}
186				break;
187			}
188	if (!rval)
189		(void)printf("zero%s", lflag ? "" : ".\n");
190	}
191}
192
193void
194convertexp(char *line)
195{
196	char locline[LINELEN];
197	char *part1, *part2, *part3, *part4;
198	char tmp[2];
199	int  i, j;
200
201	(void)strlcpy(locline,line,LINELEN);
202	part3 = locline;
203	part2 = strsep(&part3, "eE");	/* part3 is the exponent */
204	part4 = part3;
205	(void)strsep(&part4, ".");	/* no decimal allowed in the exponent */
206	if (part4)
207		errx(1, "illegal number: %s", line);
208	part1 = strsep(&part2, ".");	/* we can have one in the mantissa */
209	/* At this point everything should be null or a digit.  Check for
210	 * that before starting to convert.  Two characters may be + or -.
211	 */
212	j = strlen(line);
213	for (i = 0; i < j; i++)
214		if ((!isdigit((unsigned char)locline[i])) && (locline[i]))
215			if (((locline[i] != '+') && (locline[i] != '-')) ||
216				((i != 0) && (i != part3 - locline)))
217				errx(1, "illegal number: %s", line);
218	convert(part1);
219	printf("%s", lflag ? " " : "");
220	if (part2 && part2[0]) {	/* do individual digits separately */
221		(void)printf("point%s", lflag ? " " : "\n");
222		j = strlen(part2); tmp[1] = '\0';
223		for (i = 0 ; i < j; i++ ) {
224			tmp[0] = part2[i];
225			convert(tmp);
226			(void)printf("%s", lflag ? " " : "");
227		}
228	}
229	(void)printf("times ten to the%s", lflag ? " " : "\n");
230	if (part3 && part3[0])
231		convert(part3);
232	else
233		(void)printf("zero%s", lflag ? " " : ".\n");
234}
235
236int
237unit(int len, const char *p)
238{
239	int off, rval;
240
241	rval = 0;
242	if (len > 3) {
243		if (len % 3) {
244			off = len % 3;
245			len -= off;
246			if (number(p, off)) {
247				rval = 1;
248				(void)printf(" %s%s",
249				    name3[len / 3], lflag ? " " : ".\n");
250			}
251			p += off;
252		}
253		for (; len > 3; p += 3) {
254			len -= 3;
255			if (number(p, 3)) {
256				rval = 1;
257				(void)printf(" %s%s",
258				    name3[len / 3], lflag ? " " : ".\n");
259			}
260		}
261	}
262	if (number(p, len)) {
263		if (!lflag)
264			(void)printf(".\n");
265		rval = 1;
266	}
267	return (rval);
268}
269
270int
271number(const char *p, int len)
272{
273	int val, rval;
274
275	rval = 0;
276	switch (len) {
277	case 3:
278		if (*p != '0') {
279			rval = 1;
280			(void)printf("%s hundred", name1[*p - '0']);
281		}
282		++p;
283		/* FALLTHROUGH */
284	case 2:
285		val = (p[1] - '0') + (p[0] - '0') * 10;
286		if (val) {
287			if (rval)
288				(void)printf(" ");
289			if (val < 20)
290				(void)printf("%s", name1[val]);
291			else {
292				(void)printf("%s", name2[val / 10]);
293				if (val % 10)
294					(void)printf("-%s", name1[val % 10]);
295			}
296			rval = 1;
297		}
298		break;
299	case 1:
300		if (*p != '0') {
301			rval = 1;
302			(void)printf("%s", name1[*p - '0']);
303		}
304	}
305	return (rval);
306}
307
308void
309pfract(int len)
310{
311	static const char *const pref[] = { "", "ten-", "hundred-" };
312
313	switch(len) {
314	case 1:
315		(void)printf("tenths%s", lflag ? "" : ".\n");
316		break;
317	case 2:
318		(void)printf("hundredths%s", lflag ? "" : ".\n");
319		break;
320	default:
321		(void)printf("%s%sths%s", pref[len % 3], name3[len / 3],
322		    lflag ? "" : ".\n");
323		break;
324	}
325}
326
327void
328usage(void)
329{
330	(void)fprintf(stderr, "usage: %s [-l] [--] [# ...]\n", getprogname());
331	exit(1);
332}
333