xref: /freebsd/usr.bin/seq/seq.c (revision 641a6cfb86023499caafe26a4d821a0b885cf00b)
1 /*	$NetBSD: seq.c,v 1.5 2008/07/21 14:19:26 lukem Exp $	*/
2 /*
3  * Copyright (c) 2005 The NetBSD Foundation, Inc.
4  * All rights reserved.
5  *
6  * This code is derived from software contributed to The NetBSD Foundation
7  * by Brian Ginsbach.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <ctype.h>
35 #include <err.h>
36 #include <errno.h>
37 #include <math.h>
38 #include <locale.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <unistd.h>
43 
44 #define ZERO	'0'
45 #define SPACE	' '
46 
47 #define MAX(a, b)	(((a) < (b))? (b) : (a))
48 #define ISSIGN(c)	((int)(c) == '-' || (int)(c) == '+')
49 #define ISEXP(c)	((int)(c) == 'e' || (int)(c) == 'E')
50 #define ISODIGIT(c)	((int)(c) >= '0' && (int)(c) <= '7')
51 
52 /* Globals */
53 
54 static const char *decimal_point = ".";	/* default */
55 static char default_format[] = { "%g" };	/* default */
56 
57 /* Prototypes */
58 
59 static double e_atof(const char *);
60 
61 static int decimal_places(const char *);
62 static int numeric(const char *);
63 static int valid_format(const char *);
64 
65 static char *generate_format(double, double, double, int, char);
66 static char *unescape(char *);
67 
68 /*
69  * The seq command will print out a numeric sequence from 1, the default,
70  * to a user specified upper limit by 1.  The lower bound and increment
71  * maybe indicated by the user on the command line.  The sequence can
72  * be either whole, the default, or decimal numbers.
73  */
74 int
75 main(int argc, char *argv[])
76 {
77 	int c = 0, errflg = 0;
78 	int equalize = 0;
79 	double first = 1.0;
80 	double last = 0.0;
81 	double incr = 0.0;
82 	struct lconv *locale;
83 	char *fmt = NULL;
84 	const char *sep = "\n";
85 	const char *term = NULL;
86 	char pad = ZERO;
87 
88 	/* Determine the locale's decimal point. */
89 	locale = localeconv();
90 	if (locale && locale->decimal_point && locale->decimal_point[0] != '\0')
91 		decimal_point = locale->decimal_point;
92 
93 	/*
94          * Process options, but handle negative numbers separately
95          * least they trip up getopt(3).
96          */
97 	while ((optind < argc) && !numeric(argv[optind]) &&
98 	    (c = getopt(argc, argv, "f:hs:t:w")) != -1) {
99 
100 		switch (c) {
101 		case 'f':	/* format (plan9) */
102 			fmt = optarg;
103 			equalize = 0;
104 			break;
105 		case 's':	/* separator (GNU) */
106 			sep = unescape(optarg);
107 			break;
108 		case 't':	/* terminator (new) */
109 			term = unescape(optarg);
110 			break;
111 		case 'w':	/* equal width (plan9) */
112 			if (!fmt)
113 				if (equalize++)
114 					pad = SPACE;
115 			break;
116 		case 'h':	/* help (GNU) */
117 		default:
118 			errflg++;
119 			break;
120 		}
121 	}
122 
123 	argc -= optind;
124 	argv += optind;
125 	if (argc < 1 || argc > 3)
126 		errflg++;
127 
128 	if (errflg) {
129 		fprintf(stderr,
130 		    "usage: %s [-w] [-f format] [-s string] [-t string] [first [incr]] last\n",
131 		    getprogname());
132 		exit(1);
133 	}
134 
135 	last = e_atof(argv[argc - 1]);
136 
137 	if (argc > 1)
138 		first = e_atof(argv[0]);
139 
140 	if (argc > 2) {
141 		incr = e_atof(argv[1]);
142 		/* Plan 9/GNU don't do zero */
143 		if (incr == 0.0)
144 			errx(1, "zero %screment", (first < last)? "in" : "de");
145 	}
146 
147 	/* default is one for Plan 9/GNU work alike */
148 	if (incr == 0.0)
149 		incr = (first < last) ? 1.0 : -1.0;
150 
151 	if (incr <= 0.0 && first < last)
152 		errx(1, "needs positive increment");
153 
154 	if (incr >= 0.0 && first > last)
155 		errx(1, "needs negative decrement");
156 
157 	if (fmt != NULL) {
158 		if (!valid_format(fmt))
159 			errx(1, "invalid format string: `%s'", fmt);
160 		fmt = unescape(fmt);
161 		/*
162 	         * XXX to be bug for bug compatible with Plan 9 add a
163 		 * newline if none found at the end of the format string.
164 		 */
165 	} else
166 		fmt = generate_format(first, incr, last, equalize, pad);
167 
168 	if (incr > 0) {
169 		for (; first <= last; first += incr) {
170 			printf(fmt, first);
171 			fputs(sep, stdout);
172 		}
173 	} else {
174 		for (; first >= last; first += incr) {
175 			printf(fmt, first);
176 			fputs(sep, stdout);
177 		}
178 	}
179 	if (term != NULL)
180 		fputs(term, stdout);
181 
182 	return (0);
183 }
184 
185 /*
186  * numeric - verify that string is numeric
187  */
188 static int
189 numeric(const char *s)
190 {
191 	int seen_decimal_pt, decimal_pt_len;
192 
193 	/* skip any sign */
194 	if (ISSIGN((unsigned char)*s))
195 		s++;
196 
197 	seen_decimal_pt = 0;
198 	decimal_pt_len = strlen(decimal_point);
199 	while (*s) {
200 		if (!isdigit((unsigned char)*s)) {
201 			if (!seen_decimal_pt &&
202 			    strncmp(s, decimal_point, decimal_pt_len) == 0) {
203 				s += decimal_pt_len;
204 				seen_decimal_pt = 1;
205 				continue;
206 			}
207 			if (ISEXP((unsigned char)*s)) {
208 				s++;
209 				if (ISSIGN((unsigned char)*s) ||
210 				    isdigit((unsigned char)*s)) {
211 					s++;
212 					continue;
213 				}
214 			}
215 			break;
216 		}
217 		s++;
218 	}
219 	return (*s == '\0');
220 }
221 
222 /*
223  * valid_format - validate user specified format string
224  */
225 static int
226 valid_format(const char *fmt)
227 {
228 	int conversions = 0;
229 
230 	while (*fmt != '\0') {
231 		/* scan for conversions */
232 		if (*fmt != '\0' && *fmt != '%') {
233 			do {
234 				fmt++;
235 			} while (*fmt != '\0' && *fmt != '%');
236 		}
237 		/* scan a conversion */
238 		if (*fmt != '\0') {
239 			do {
240 				fmt++;
241 
242 				/* ok %% */
243 				if (*fmt == '%') {
244 					fmt++;
245 					break;
246 				}
247 				/* valid conversions */
248 				if (strchr("eEfgG", *fmt) &&
249 				    conversions++ < 1) {
250 					fmt++;
251 					break;
252 				}
253 				/* flags, width and precision */
254 				if (isdigit((unsigned char)*fmt) ||
255 				    strchr("+- 0#.", *fmt))
256 					continue;
257 
258 				/* oops! bad conversion format! */
259 				return (0);
260 			} while (*fmt != '\0');
261 		}
262 	}
263 
264 	return (conversions <= 1);
265 }
266 
267 /*
268  * unescape - handle C escapes in a string
269  */
270 static char *
271 unescape(char *orig)
272 {
273 	char c, *cp, *new = orig;
274 	int i;
275 
276 	for (cp = orig; (*orig = *cp); cp++, orig++) {
277 		if (*cp != '\\')
278 			continue;
279 
280 		switch (*++cp) {
281 		case 'a':	/* alert (bell) */
282 			*orig = '\a';
283 			continue;
284 		case 'b':	/* backspace */
285 			*orig = '\b';
286 			continue;
287 		case 'e':	/* escape */
288 			*orig = '\e';
289 			continue;
290 		case 'f':	/* formfeed */
291 			*orig = '\f';
292 			continue;
293 		case 'n':	/* newline */
294 			*orig = '\n';
295 			continue;
296 		case 'r':	/* carriage return */
297 			*orig = '\r';
298 			continue;
299 		case 't':	/* horizontal tab */
300 			*orig = '\t';
301 			continue;
302 		case 'v':	/* vertical tab */
303 			*orig = '\v';
304 			continue;
305 		case '\\':	/* backslash */
306 			*orig = '\\';
307 			continue;
308 		case '\'':	/* single quote */
309 			*orig = '\'';
310 			continue;
311 		case '\"':	/* double quote */
312 			*orig = '"';
313 			continue;
314 		case '0':
315 		case '1':
316 		case '2':
317 		case '3':	/* octal */
318 		case '4':
319 		case '5':
320 		case '6':
321 		case '7':	/* number */
322 			for (i = 0, c = 0;
323 			     ISODIGIT((unsigned char)*cp) && i < 3;
324 			     i++, cp++) {
325 				c <<= 3;
326 				c |= (*cp - '0');
327 			}
328 			*orig = c;
329 			--cp;
330 			continue;
331 		case 'x':	/* hexadecimal number */
332 			cp++;	/* skip 'x' */
333 			for (i = 0, c = 0;
334 			     isxdigit((unsigned char)*cp) && i < 2;
335 			     i++, cp++) {
336 				c <<= 4;
337 				if (isdigit((unsigned char)*cp))
338 					c |= (*cp - '0');
339 				else
340 					c |= ((toupper((unsigned char)*cp) -
341 					    'A') + 10);
342 			}
343 			*orig = c;
344 			--cp;
345 			continue;
346 		default:
347 			--cp;
348 			break;
349 		}
350 	}
351 
352 	return (new);
353 }
354 
355 /*
356  * e_atof - convert an ASCII string to a double
357  *	exit if string is not a valid double, or if converted value would
358  *	cause overflow or underflow
359  */
360 static double
361 e_atof(const char *num)
362 {
363 	char *endp;
364 	double dbl;
365 
366 	errno = 0;
367 	dbl = strtod(num, &endp);
368 
369 	if (errno == ERANGE)
370 		/* under or overflow */
371 		err(2, "%s", num);
372 	else if (*endp != '\0')
373 		/* "junk" left in number */
374 		errx(2, "invalid floating point argument: %s", num);
375 
376 	/* zero shall have no sign */
377 	if (dbl == -0.0)
378 		dbl = 0;
379 	return (dbl);
380 }
381 
382 /*
383  * decimal_places - count decimal places in a number (string)
384  */
385 static int
386 decimal_places(const char *number)
387 {
388 	int places = 0;
389 	char *dp;
390 
391 	/* look for a decimal point */
392 	if ((dp = strstr(number, decimal_point))) {
393 		dp += strlen(decimal_point);
394 
395 		while (isdigit((unsigned char)*dp++))
396 			places++;
397 	}
398 	return (places);
399 }
400 
401 /*
402  * generate_format - create a format string
403  *
404  * XXX to be bug for bug compatible with Plan9 and GNU return "%g"
405  * when "%g" prints as "%e" (this way no width adjustments are made)
406  */
407 static char *
408 generate_format(double first, double incr, double last, int equalize, char pad)
409 {
410 	static char buf[256];
411 	char cc = '\0';
412 	int precision, width1, width2, places;
413 
414 	if (equalize == 0)
415 		return (default_format);
416 
417 	/* figure out "last" value printed */
418 	if (first > last)
419 		last = first - incr * floor((first - last) / incr);
420 	else
421 		last = first + incr * floor((last - first) / incr);
422 
423 	sprintf(buf, "%g", incr);
424 	if (strchr(buf, 'e'))
425 		cc = 'e';
426 	precision = decimal_places(buf);
427 
428 	width1 = sprintf(buf, "%g", first);
429 	if (strchr(buf, 'e'))
430 		cc = 'e';
431 	if ((places = decimal_places(buf)))
432 		width1 -= (places + strlen(decimal_point));
433 
434 	precision = MAX(places, precision);
435 
436 	width2 = sprintf(buf, "%g", last);
437 	if (strchr(buf, 'e'))
438 		cc = 'e';
439 	if ((places = decimal_places(buf)))
440 		width2 -= (places + strlen(decimal_point));
441 
442 	if (precision) {
443 		sprintf(buf, "%%%c%d.%d%c", pad,
444 		    MAX(width1, width2) + (int) strlen(decimal_point) +
445 		    precision, precision, (cc) ? cc : 'f');
446 	} else {
447 		sprintf(buf, "%%%c%d%c", pad, MAX(width1, width2),
448 		    (cc) ? cc : 'g');
449 	}
450 
451 	return (buf);
452 }
453