xref: /freebsd/usr.bin/seq/seq.c (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
1 /*	$NetBSD: seq.c,v 1.7 2010/05/27 08:40:19 dholland Exp $	*/
2 /*-
3  * SPDX-License-Identifier: BSD-2-Clause-NetBSD
4  *
5  * Copyright (c) 2005 The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to The NetBSD Foundation
9  * by Brian Ginsbach.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <ctype.h>
37 #include <err.h>
38 #include <errno.h>
39 #include <math.h>
40 #include <locale.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 
46 #define ZERO	'0'
47 #define SPACE	' '
48 
49 #define MAX(a, b)	(((a) < (b))? (b) : (a))
50 #define ISSIGN(c)	((int)(c) == '-' || (int)(c) == '+')
51 #define ISEXP(c)	((int)(c) == 'e' || (int)(c) == 'E')
52 #define ISODIGIT(c)	((int)(c) >= '0' && (int)(c) <= '7')
53 
54 /* Globals */
55 
56 static const char *decimal_point = ".";	/* default */
57 static char default_format[] = { "%g" };	/* default */
58 
59 /* Prototypes */
60 
61 static double e_atof(const char *);
62 
63 static int decimal_places(const char *);
64 static int numeric(const char *);
65 static int valid_format(const char *);
66 
67 static char *generate_format(double, double, double, int, char);
68 static char *unescape(char *);
69 
70 /*
71  * The seq command will print out a numeric sequence from 1, the default,
72  * to a user specified upper limit by 1.  The lower bound and increment
73  * maybe indicated by the user on the command line.  The sequence can
74  * be either whole, the default, or decimal numbers.
75  */
76 int
77 main(int argc, char *argv[])
78 {
79 	int c = 0, errflg = 0;
80 	int equalize = 0;
81 	double first = 1.0;
82 	double last = 0.0;
83 	double incr = 0.0;
84 	struct lconv *locale;
85 	char *fmt = NULL;
86 	const char *sep = "\n";
87 	const char *term = NULL;
88 	char pad = ZERO;
89 
90 	/* Determine the locale's decimal point. */
91 	locale = localeconv();
92 	if (locale && locale->decimal_point && locale->decimal_point[0] != '\0')
93 		decimal_point = locale->decimal_point;
94 
95 	/*
96          * Process options, but handle negative numbers separately
97          * least they trip up getopt(3).
98          */
99 	while ((optind < argc) && !numeric(argv[optind]) &&
100 	    (c = getopt(argc, argv, "f:hs:t:w")) != -1) {
101 
102 		switch (c) {
103 		case 'f':	/* format (plan9) */
104 			fmt = optarg;
105 			equalize = 0;
106 			break;
107 		case 's':	/* separator (GNU) */
108 			sep = unescape(optarg);
109 			break;
110 		case 't':	/* terminator (new) */
111 			term = unescape(optarg);
112 			break;
113 		case 'w':	/* equal width (plan9) */
114 			if (!fmt)
115 				if (equalize++)
116 					pad = SPACE;
117 			break;
118 		case 'h':	/* help (GNU) */
119 		default:
120 			errflg++;
121 			break;
122 		}
123 	}
124 
125 	argc -= optind;
126 	argv += optind;
127 	if (argc < 1 || argc > 3)
128 		errflg++;
129 
130 	if (errflg) {
131 		fprintf(stderr,
132 		    "usage: %s [-w] [-f format] [-s string] [-t string] [first [incr]] last\n",
133 		    getprogname());
134 		exit(1);
135 	}
136 
137 	last = e_atof(argv[argc - 1]);
138 
139 	if (argc > 1)
140 		first = e_atof(argv[0]);
141 
142 	if (argc > 2) {
143 		incr = e_atof(argv[1]);
144 		/* Plan 9/GNU don't do zero */
145 		if (incr == 0.0)
146 			errx(1, "zero %screment", (first < last)? "in" : "de");
147 	}
148 
149 	/* default is one for Plan 9/GNU work alike */
150 	if (incr == 0.0)
151 		incr = (first < last) ? 1.0 : -1.0;
152 
153 	if (incr <= 0.0 && first < last)
154 		errx(1, "needs positive increment");
155 
156 	if (incr >= 0.0 && first > last)
157 		errx(1, "needs negative decrement");
158 
159 	if (fmt != NULL) {
160 		if (!valid_format(fmt))
161 			errx(1, "invalid format string: `%s'", fmt);
162 		fmt = unescape(fmt);
163 		if (!valid_format(fmt))
164 			errx(1, "invalid format string");
165 		/*
166 	         * XXX to be bug for bug compatible with Plan 9 add a
167 		 * newline if none found at the end of the format string.
168 		 */
169 	} else
170 		fmt = generate_format(first, incr, last, equalize, pad);
171 
172 	if (incr > 0) {
173 		for (; first <= last; first += incr) {
174 			printf(fmt, first);
175 			fputs(sep, stdout);
176 		}
177 	} else {
178 		for (; first >= last; first += incr) {
179 			printf(fmt, first);
180 			fputs(sep, stdout);
181 		}
182 	}
183 	if (term != NULL)
184 		fputs(term, stdout);
185 
186 	return (0);
187 }
188 
189 /*
190  * numeric - verify that string is numeric
191  */
192 static int
193 numeric(const char *s)
194 {
195 	int seen_decimal_pt, decimal_pt_len;
196 
197 	/* skip any sign */
198 	if (ISSIGN((unsigned char)*s))
199 		s++;
200 
201 	seen_decimal_pt = 0;
202 	decimal_pt_len = strlen(decimal_point);
203 	while (*s) {
204 		if (!isdigit((unsigned char)*s)) {
205 			if (!seen_decimal_pt &&
206 			    strncmp(s, decimal_point, decimal_pt_len) == 0) {
207 				s += decimal_pt_len;
208 				seen_decimal_pt = 1;
209 				continue;
210 			}
211 			if (ISEXP((unsigned char)*s)) {
212 				s++;
213 				if (ISSIGN((unsigned char)*s) ||
214 				    isdigit((unsigned char)*s)) {
215 					s++;
216 					continue;
217 				}
218 			}
219 			break;
220 		}
221 		s++;
222 	}
223 	return (*s == '\0');
224 }
225 
226 /*
227  * valid_format - validate user specified format string
228  */
229 static int
230 valid_format(const char *fmt)
231 {
232 	unsigned conversions = 0;
233 
234 	while (*fmt != '\0') {
235 		/* scan for conversions */
236 		if (*fmt != '%') {
237 			fmt++;
238 			continue;
239 		}
240 		fmt++;
241 
242 		/* allow %% but not things like %10% */
243 		if (*fmt == '%') {
244 			fmt++;
245 			continue;
246 		}
247 
248 		/* flags */
249 		while (*fmt != '\0' && strchr("#0- +'", *fmt)) {
250 			fmt++;
251 		}
252 
253 		/* field width */
254 		while (*fmt != '\0' && strchr("0123456789", *fmt)) {
255 			fmt++;
256 		}
257 
258 		/* precision */
259 		if (*fmt == '.') {
260 			fmt++;
261 			while (*fmt != '\0' && strchr("0123456789", *fmt)) {
262 				fmt++;
263 			}
264 		}
265 
266 		/* conversion */
267 		switch (*fmt) {
268 		    case 'A':
269 		    case 'a':
270 		    case 'E':
271 		    case 'e':
272 		    case 'F':
273 		    case 'f':
274 		    case 'G':
275 		    case 'g':
276 			/* floating point formats are accepted */
277 			conversions++;
278 			break;
279 		    default:
280 			/* anything else is not */
281 			return 0;
282 		}
283 	}
284 
285 	return (conversions <= 1);
286 }
287 
288 /*
289  * unescape - handle C escapes in a string
290  */
291 static char *
292 unescape(char *orig)
293 {
294 	char c, *cp, *new = orig;
295 	int i;
296 
297 	for (cp = orig; (*orig = *cp); cp++, orig++) {
298 		if (*cp != '\\')
299 			continue;
300 
301 		switch (*++cp) {
302 		case 'a':	/* alert (bell) */
303 			*orig = '\a';
304 			continue;
305 		case 'b':	/* backspace */
306 			*orig = '\b';
307 			continue;
308 		case 'e':	/* escape */
309 			*orig = '\e';
310 			continue;
311 		case 'f':	/* formfeed */
312 			*orig = '\f';
313 			continue;
314 		case 'n':	/* newline */
315 			*orig = '\n';
316 			continue;
317 		case 'r':	/* carriage return */
318 			*orig = '\r';
319 			continue;
320 		case 't':	/* horizontal tab */
321 			*orig = '\t';
322 			continue;
323 		case 'v':	/* vertical tab */
324 			*orig = '\v';
325 			continue;
326 		case '\\':	/* backslash */
327 			*orig = '\\';
328 			continue;
329 		case '\'':	/* single quote */
330 			*orig = '\'';
331 			continue;
332 		case '\"':	/* double quote */
333 			*orig = '"';
334 			continue;
335 		case '0':
336 		case '1':
337 		case '2':
338 		case '3':	/* octal */
339 		case '4':
340 		case '5':
341 		case '6':
342 		case '7':	/* number */
343 			for (i = 0, c = 0;
344 			     ISODIGIT((unsigned char)*cp) && i < 3;
345 			     i++, cp++) {
346 				c <<= 3;
347 				c |= (*cp - '0');
348 			}
349 			*orig = c;
350 			--cp;
351 			continue;
352 		case 'x':	/* hexadecimal number */
353 			cp++;	/* skip 'x' */
354 			for (i = 0, c = 0;
355 			     isxdigit((unsigned char)*cp) && i < 2;
356 			     i++, cp++) {
357 				c <<= 4;
358 				if (isdigit((unsigned char)*cp))
359 					c |= (*cp - '0');
360 				else
361 					c |= ((toupper((unsigned char)*cp) -
362 					    'A') + 10);
363 			}
364 			*orig = c;
365 			--cp;
366 			continue;
367 		default:
368 			--cp;
369 			break;
370 		}
371 	}
372 
373 	return (new);
374 }
375 
376 /*
377  * e_atof - convert an ASCII string to a double
378  *	exit if string is not a valid double, or if converted value would
379  *	cause overflow or underflow
380  */
381 static double
382 e_atof(const char *num)
383 {
384 	char *endp;
385 	double dbl;
386 
387 	errno = 0;
388 	dbl = strtod(num, &endp);
389 
390 	if (errno == ERANGE)
391 		/* under or overflow */
392 		err(2, "%s", num);
393 	else if (*endp != '\0')
394 		/* "junk" left in number */
395 		errx(2, "invalid floating point argument: %s", num);
396 
397 	/* zero shall have no sign */
398 	if (dbl == -0.0)
399 		dbl = 0;
400 	return (dbl);
401 }
402 
403 /*
404  * decimal_places - count decimal places in a number (string)
405  */
406 static int
407 decimal_places(const char *number)
408 {
409 	int places = 0;
410 	char *dp;
411 
412 	/* look for a decimal point */
413 	if ((dp = strstr(number, decimal_point))) {
414 		dp += strlen(decimal_point);
415 
416 		while (isdigit((unsigned char)*dp++))
417 			places++;
418 	}
419 	return (places);
420 }
421 
422 /*
423  * generate_format - create a format string
424  *
425  * XXX to be bug for bug compatible with Plan9 and GNU return "%g"
426  * when "%g" prints as "%e" (this way no width adjustments are made)
427  */
428 static char *
429 generate_format(double first, double incr, double last, int equalize, char pad)
430 {
431 	static char buf[256];
432 	char cc = '\0';
433 	int precision, width1, width2, places;
434 
435 	if (equalize == 0)
436 		return (default_format);
437 
438 	/* figure out "last" value printed */
439 	if (first > last)
440 		last = first - incr * floor((first - last) / incr);
441 	else
442 		last = first + incr * floor((last - first) / incr);
443 
444 	sprintf(buf, "%g", incr);
445 	if (strchr(buf, 'e'))
446 		cc = 'e';
447 	precision = decimal_places(buf);
448 
449 	width1 = sprintf(buf, "%g", first);
450 	if (strchr(buf, 'e'))
451 		cc = 'e';
452 	if ((places = decimal_places(buf)))
453 		width1 -= (places + strlen(decimal_point));
454 
455 	precision = MAX(places, precision);
456 
457 	width2 = sprintf(buf, "%g", last);
458 	if (strchr(buf, 'e'))
459 		cc = 'e';
460 	if ((places = decimal_places(buf)))
461 		width2 -= (places + strlen(decimal_point));
462 
463 	if (precision) {
464 		sprintf(buf, "%%%c%d.%d%c", pad,
465 		    MAX(width1, width2) + (int) strlen(decimal_point) +
466 		    precision, precision, (cc) ? cc : 'f');
467 	} else {
468 		sprintf(buf, "%%%c%d%c", pad, MAX(width1, width2),
469 		    (cc) ? cc : 'g');
470 	}
471 
472 	return (buf);
473 }
474