xref: /freebsd/usr.bin/seq/seq.c (revision ae1f3df43466466a21c7da0df93ecb58a3e53d74) 
1 /*	$NetBSD: seq.c,v 1.7 2010/05/27 08:40:19 dholland 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 		if (!valid_format(fmt))
162 			errx(1, "invalid format string");
163 		/*
164 	         * XXX to be bug for bug compatible with Plan 9 add a
165 		 * newline if none found at the end of the format string.
166 		 */
167 	} else
168 		fmt = generate_format(first, incr, last, equalize, pad);
169 
170 	if (incr > 0) {
171 		for (; first <= last; first += incr) {
172 			printf(fmt, first);
173 			fputs(sep, stdout);
174 		}
175 	} else {
176 		for (; first >= last; first += incr) {
177 			printf(fmt, first);
178 			fputs(sep, stdout);
179 		}
180 	}
181 	if (term != NULL)
182 		fputs(term, stdout);
183 
184 	return (0);
185 }
186 
187 /*
188  * numeric - verify that string is numeric
189  */
190 static int
191 numeric(const char *s)
192 {
193 	int seen_decimal_pt, decimal_pt_len;
194 
195 	/* skip any sign */
196 	if (ISSIGN((unsigned char)*s))
197 		s++;
198 
199 	seen_decimal_pt = 0;
200 	decimal_pt_len = strlen(decimal_point);
201 	while (*s) {
202 		if (!isdigit((unsigned char)*s)) {
203 			if (!seen_decimal_pt &&
204 			    strncmp(s, decimal_point, decimal_pt_len) == 0) {
205 				s += decimal_pt_len;
206 				seen_decimal_pt = 1;
207 				continue;
208 			}
209 			if (ISEXP((unsigned char)*s)) {
210 				s++;
211 				if (ISSIGN((unsigned char)*s) ||
212 				    isdigit((unsigned char)*s)) {
213 					s++;
214 					continue;
215 				}
216 			}
217 			break;
218 		}
219 		s++;
220 	}
221 	return (*s == '\0');
222 }
223 
224 /*
225  * valid_format - validate user specified format string
226  */
227 static int
228 valid_format(const char *fmt)
229 {
230 	unsigned conversions = 0;
231 
232 	while (*fmt != '\0') {
233 		/* scan for conversions */
234 		if (*fmt != '%') {
235 			fmt++;
236 			continue;
237 		}
238 		fmt++;
239 
240 		/* allow %% but not things like %10% */
241 		if (*fmt == '%') {
242 			fmt++;
243 			continue;
244 		}
245 
246 		/* flags */
247 		while (*fmt != '\0' && strchr("#0- +'", *fmt)) {
248 			fmt++;
249 		}
250 
251 		/* field width */
252 		while (*fmt != '\0' && strchr("0123456789", *fmt)) {
253 			fmt++;
254 		}
255 
256 		/* precision */
257 		if (*fmt == '.') {
258 			fmt++;
259 			while (*fmt != '\0' && strchr("0123456789", *fmt)) {
260 				fmt++;
261 			}
262 		}
263 
264 		/* conversion */
265 		switch (*fmt) {
266 		    case 'A':
267 		    case 'a':
268 		    case 'E':
269 		    case 'e':
270 		    case 'F':
271 		    case 'f':
272 		    case 'G':
273 		    case 'g':
274 			/* floating point formats are accepted */
275 			conversions++;
276 			break;
277 		    default:
278 			/* anything else is not */
279 			return 0;
280 		}
281 	}
282 
283 	return (conversions <= 1);
284 }
285 
286 /*
287  * unescape - handle C escapes in a string
288  */
289 static char *
290 unescape(char *orig)
291 {
292 	char c, *cp, *new = orig;
293 	int i;
294 
295 	for (cp = orig; (*orig = *cp); cp++, orig++) {
296 		if (*cp != '\\')
297 			continue;
298 
299 		switch (*++cp) {
300 		case 'a':	/* alert (bell) */
301 			*orig = '\a';
302 			continue;
303 		case 'b':	/* backspace */
304 			*orig = '\b';
305 			continue;
306 		case 'e':	/* escape */
307 			*orig = '\e';
308 			continue;
309 		case 'f':	/* formfeed */
310 			*orig = '\f';
311 			continue;
312 		case 'n':	/* newline */
313 			*orig = '\n';
314 			continue;
315 		case 'r':	/* carriage return */
316 			*orig = '\r';
317 			continue;
318 		case 't':	/* horizontal tab */
319 			*orig = '\t';
320 			continue;
321 		case 'v':	/* vertical tab */
322 			*orig = '\v';
323 			continue;
324 		case '\\':	/* backslash */
325 			*orig = '\\';
326 			continue;
327 		case '\'':	/* single quote */
328 			*orig = '\'';
329 			continue;
330 		case '\"':	/* double quote */
331 			*orig = '"';
332 			continue;
333 		case '0':
334 		case '1':
335 		case '2':
336 		case '3':	/* octal */
337 		case '4':
338 		case '5':
339 		case '6':
340 		case '7':	/* number */
341 			for (i = 0, c = 0;
342 			     ISODIGIT((unsigned char)*cp) && i < 3;
343 			     i++, cp++) {
344 				c <<= 3;
345 				c |= (*cp - '0');
346 			}
347 			*orig = c;
348 			--cp;
349 			continue;
350 		case 'x':	/* hexadecimal number */
351 			cp++;	/* skip 'x' */
352 			for (i = 0, c = 0;
353 			     isxdigit((unsigned char)*cp) && i < 2;
354 			     i++, cp++) {
355 				c <<= 4;
356 				if (isdigit((unsigned char)*cp))
357 					c |= (*cp - '0');
358 				else
359 					c |= ((toupper((unsigned char)*cp) -
360 					    'A') + 10);
361 			}
362 			*orig = c;
363 			--cp;
364 			continue;
365 		default:
366 			--cp;
367 			break;
368 		}
369 	}
370 
371 	return (new);
372 }
373 
374 /*
375  * e_atof - convert an ASCII string to a double
376  *	exit if string is not a valid double, or if converted value would
377  *	cause overflow or underflow
378  */
379 static double
380 e_atof(const char *num)
381 {
382 	char *endp;
383 	double dbl;
384 
385 	errno = 0;
386 	dbl = strtod(num, &endp);
387 
388 	if (errno == ERANGE)
389 		/* under or overflow */
390 		err(2, "%s", num);
391 	else if (*endp != '\0')
392 		/* "junk" left in number */
393 		errx(2, "invalid floating point argument: %s", num);
394 
395 	/* zero shall have no sign */
396 	if (dbl == -0.0)
397 		dbl = 0;
398 	return (dbl);
399 }
400 
401 /*
402  * decimal_places - count decimal places in a number (string)
403  */
404 static int
405 decimal_places(const char *number)
406 {
407 	int places = 0;
408 	char *dp;
409 
410 	/* look for a decimal point */
411 	if ((dp = strstr(number, decimal_point))) {
412 		dp += strlen(decimal_point);
413 
414 		while (isdigit((unsigned char)*dp++))
415 			places++;
416 	}
417 	return (places);
418 }
419 
420 /*
421  * generate_format - create a format string
422  *
423  * XXX to be bug for bug compatible with Plan9 and GNU return "%g"
424  * when "%g" prints as "%e" (this way no width adjustments are made)
425  */
426 static char *
427 generate_format(double first, double incr, double last, int equalize, char pad)
428 {
429 	static char buf[256];
430 	char cc = '\0';
431 	int precision, width1, width2, places;
432 
433 	if (equalize == 0)
434 		return (default_format);
435 
436 	/* figure out "last" value printed */
437 	if (first > last)
438 		last = first - incr * floor((first - last) / incr);
439 	else
440 		last = first + incr * floor((last - first) / incr);
441 
442 	sprintf(buf, "%g", incr);
443 	if (strchr(buf, 'e'))
444 		cc = 'e';
445 	precision = decimal_places(buf);
446 
447 	width1 = sprintf(buf, "%g", first);
448 	if (strchr(buf, 'e'))
449 		cc = 'e';
450 	if ((places = decimal_places(buf)))
451 		width1 -= (places + strlen(decimal_point));
452 
453 	precision = MAX(places, precision);
454 
455 	width2 = sprintf(buf, "%g", last);
456 	if (strchr(buf, 'e'))
457 		cc = 'e';
458 	if ((places = decimal_places(buf)))
459 		width2 -= (places + strlen(decimal_point));
460 
461 	if (precision) {
462 		sprintf(buf, "%%%c%d.%d%c", pad,
463 		    MAX(width1, width2) + (int) strlen(decimal_point) +
464 		    precision, precision, (cc) ? cc : 'f');
465 	} else {
466 		sprintf(buf, "%%%c%d%c", pad, MAX(width1, width2),
467 		    (cc) ? cc : 'g');
468 	}
469 
470 	return (buf);
471 }
472