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seq.c revision 1.5 
      1 /*
      2  * Copyright (c) 2005 The NetBSD Foundation, Inc.
      3  * All rights reserved.
      4  *
      5  * This code is derived from software contributed to The NetBSD Foundation
      6  * by Brian Ginsbach.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     19  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     20  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     21  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     27  * POSSIBILITY OF SUCH DAMAGE.
     28  */
     29 
     30 #include <sys/cdefs.h>
     31 #ifndef lint
     32 __COPYRIGHT("@(#) Copyright (c) 2005\
     33  The NetBSD Foundation, Inc.  All rights reserved.");
     34 __RCSID("$NetBSD: seq.c,v 1.5 2008/07/21 14:19:26 lukem Exp $");
     35 #endif /* not lint */
     36 
     37 #include <ctype.h>
     38 #include <err.h>
     39 #include <errno.h>
     40 #include <math.h>
     41 #include <locale.h>
     42 #include <stdio.h>
     43 #include <stdlib.h>
     44 #include <string.h>
     45 #include <unistd.h>
     46 
     47 #define ZERO	'0'
     48 #define SPACE	' '
     49 
     50 #define MAX(a, b)	(((a) < (b))? (b) : (a))
     51 #define ISSIGN(c)	((int)(c) == '-' || (int)(c) == '+')
     52 #define ISEXP(c)	((int)(c) == 'e' || (int)(c) == 'E')
     53 #define ISODIGIT(c)	((int)(c) >= '0' && (int)(c) <= '7')
     54 
     55 /* Globals */
     56 
     57 const char *decimal_point = ".";	/* default */
     58 char default_format[] = { "%g" };	/* default */
     59 
     60 /* Prototypes */
     61 
     62 double e_atof(const char *);
     63 
     64 int decimal_places(const char *);
     65 int main(int, char *[]);
     66 int numeric(const char *);
     67 int valid_format(const char *);
     68 
     69 char *generate_format(double, double, double, int, char);
     70 char *unescape(char *);
     71 
     72 /*
     73  * The seq command will print out a numeric sequence from 1, the default,
     74  * to a user specified upper limit by 1.  The lower bound and increment
     75  * maybe indicated by the user on the command line.  The sequence can
     76  * be either whole, the default, or decimal numbers.
     77  */
     78 int
     79 main(int argc, char *argv[])
     80 {
     81 	int c = 0, errflg = 0;
     82 	int equalize = 0;
     83 	double first = 1.0;
     84 	double last = 0.0;
     85 	double incr = 0.0;
     86 	struct lconv *locale;
     87 	char *fmt = NULL;
     88 	const char *sep = "\n";
     89 	const char *term = NULL;
     90 	char pad = ZERO;
     91 
     92 	/* Determine the locale's decimal point. */
     93 	locale = localeconv();
     94 	if (locale && locale->decimal_point && locale->decimal_point[0] != '\0')
     95 		decimal_point = locale->decimal_point;
     96 
     97 	/*
     98          * Process options, but handle negative numbers separately
     99          * least they trip up getopt(3).
    100          */
    101 	while ((optind < argc) && !numeric(argv[optind]) &&
    102 	    (c = getopt(argc, argv, "f:hs:t:w")) != -1) {
    103 
    104 		switch (c) {
    105 		case 'f':	/* format (plan9) */
    106 			fmt = optarg;
    107 			equalize = 0;
    108 			break;
    109 		case 's':	/* separator (GNU) */
    110 			sep = unescape(optarg);
    111 			break;
    112 		case 't':	/* terminator (new) */
    113 			term = unescape(optarg);
    114 			break;
    115 		case 'w':	/* equal width (plan9) */
    116 			if (!fmt)
    117 				if (equalize++)
    118 					pad = SPACE;
    119 			break;
    120 		case 'h':	/* help (GNU) */
    121 		default:
    122 			errflg++;
    123 			break;
    124 		}
    125 	}
    126 
    127 	argc -= optind;
    128 	argv += optind;
    129 	if (argc < 1 || argc > 3)
    130 		errflg++;
    131 
    132 	if (errflg) {
    133 		fprintf(stderr,
    134 		    "usage: %s [-w] [-f format] [-s string] [-t string] [first [incr]] last\n",
    135 		    getprogname());
    136 		exit(1);
    137 	}
    138 
    139 	last = e_atof(argv[argc - 1]);
    140 
    141 	if (argc > 1)
    142 		first = e_atof(argv[0]);
    143 
    144 	if (argc > 2) {
    145 		incr = e_atof(argv[1]);
    146 		/* Plan 9/GNU don't do zero */
    147 		if (incr == 0.0)
    148 			errx(1, "zero %screment", (first < last)? "in" : "de");
    149 	}
    150 
    151 	/* default is one for Plan 9/GNU work alike */
    152 	if (incr == 0.0)
    153 		incr = (first < last) ? 1.0 : -1.0;
    154 
    155 	if (incr <= 0.0 && first < last)
    156 		errx(1, "needs positive increment");
    157 
    158 	if (incr >= 0.0 && first > last)
    159 		errx(1, "needs negative decrement");
    160 
    161 	if (fmt != NULL) {
    162 		if (!valid_format(fmt))
    163 			errx(1, "invalid format string: `%s'", fmt);
    164 		fmt = unescape(fmt);
    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 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 					s++;
    215 					continue;
    216 				}
    217 			}
    218 			break;
    219 		}
    220 		s++;
    221 	}
    222 	return (*s == '\0');
    223 }
    224 
    225 /*
    226  * valid_format - validate user specified format string
    227  */
    228 int
    229 valid_format(const char *fmt)
    230 {
    231 	int conversions = 0;
    232 
    233 	while (*fmt != '\0') {
    234 		/* scan for conversions */
    235 		if (*fmt != '\0' && *fmt != '%') {
    236 			do {
    237 				fmt++;
    238 			} while (*fmt != '\0' && *fmt != '%');
    239 		}
    240 		/* scan a conversion */
    241 		if (*fmt != '\0') {
    242 			do {
    243 				fmt++;
    244 
    245 				/* ok %% */
    246 				if (*fmt == '%') {
    247 					fmt++;
    248 					break;
    249 				}
    250 				/* valid conversions */
    251 				if (strchr("eEfgG", *fmt) &&
    252 				    conversions++ < 1) {
    253 					fmt++;
    254 					break;
    255 				}
    256 				/* flags, width and precsision */
    257 				if (isdigit((unsigned char)*fmt) ||
    258 				    strchr("+- 0#.", *fmt))
    259 					continue;
    260 
    261 				/* oops! bad conversion format! */
    262 				return (0);
    263 			} while (*fmt != '\0');
    264 		}
    265 	}
    266 
    267 	return (conversions <= 1);
    268 }
    269 
    270 /*
    271  * unescape - handle C escapes in a string
    272  */
    273 char *
    274 unescape(char *orig)
    275 {
    276 	char c, *cp, *new = orig;
    277 	int i;
    278 
    279 	for (cp = orig; (*orig = *cp); cp++, orig++) {
    280 		if (*cp != '\\')
    281 			continue;
    282 
    283 		switch (*++cp) {
    284 		case 'a':	/* alert (bell) */
    285 			*orig = '\a';
    286 			continue;
    287 		case 'b':	/* backspace */
    288 			*orig = '\b';
    289 			continue;
    290 		case 'e':	/* escape */
    291 			*orig = '\e';
    292 			continue;
    293 		case 'f':	/* formfeed */
    294 			*orig = '\f';
    295 			continue;
    296 		case 'n':	/* newline */
    297 			*orig = '\n';
    298 			continue;
    299 		case 'r':	/* carriage return */
    300 			*orig = '\r';
    301 			continue;
    302 		case 't':	/* horizontal tab */
    303 			*orig = '\t';
    304 			continue;
    305 		case 'v':	/* vertical tab */
    306 			*orig = '\v';
    307 			continue;
    308 		case '\\':	/* backslash */
    309 			*orig = '\\';
    310 			continue;
    311 		case '\'':	/* single quote */
    312 			*orig = '\'';
    313 			continue;
    314 		case '\"':	/* double quote */
    315 			*orig = '"';
    316 			continue;
    317 		case '0':
    318 		case '1':
    319 		case '2':
    320 		case '3':	/* octal */
    321 		case '4':
    322 		case '5':
    323 		case '6':
    324 		case '7':	/* number */
    325 			for (i = 0, c = 0;
    326 			     ISODIGIT((unsigned char)*cp) && i < 3;
    327 			     i++, cp++) {
    328 				c <<= 3;
    329 				c |= (*cp - '0');
    330 			}
    331 			*orig = c;
    332 			--cp;
    333 			continue;
    334 		case 'x':	/* hexidecimal number */
    335 			cp++;	/* skip 'x' */
    336 			for (i = 0, c = 0;
    337 			     isxdigit((unsigned char)*cp) && i < 2;
    338 			     i++, cp++) {
    339 				c <<= 4;
    340 				if (isdigit((unsigned char)*cp))
    341 					c |= (*cp - '0');
    342 				else
    343 					c |= ((toupper((unsigned char)*cp) -
    344 					    'A') + 10);
    345 			}
    346 			*orig = c;
    347 			--cp;
    348 			continue;
    349 		default:
    350 			--cp;
    351 			break;
    352 		}
    353 	}
    354 
    355 	return (new);
    356 }
    357 
    358 /*
    359  * e_atof - convert an ASCII string to a double
    360  *	exit if string is not a valid double, or if converted value would
    361  *	cause overflow or underflow
    362  */
    363 double
    364 e_atof(const char *num)
    365 {
    366 	char *endp;
    367 	double dbl;
    368 
    369 	errno = 0;
    370 	dbl = strtod(num, &endp);
    371 
    372 	if (errno == ERANGE)
    373 		/* under or overflow */
    374 		err(2, "%s", num);
    375 	else if (*endp != '\0')
    376 		/* "junk" left in number */
    377 		errx(2, "invalid floating point argument: %s", num);
    378 
    379 	/* zero shall have no sign */
    380 	if (dbl == -0.0)
    381 		dbl = 0;
    382 	return (dbl);
    383 }
    384 
    385 /*
    386  * decimal_places - count decimal places in a number (string)
    387  */
    388 int
    389 decimal_places(const char *number)
    390 {
    391 	int places = 0;
    392 	char *dp;
    393 
    394 	/* look for a decimal point */
    395 	if ((dp = strstr(number, decimal_point))) {
    396 		dp += strlen(decimal_point);
    397 
    398 		while (isdigit((unsigned char)*dp++))
    399 			places++;
    400 	}
    401 	return (places);
    402 }
    403 
    404 /*
    405  * generate_format - create a format string
    406  *
    407  * XXX to be bug for bug compatable with Plan9 and GNU return "%g"
    408  * when "%g" prints as "%e" (this way no width adjustments are made)
    409  */
    410 char *
    411 generate_format(double first, double incr, double last, int equalize, char pad)
    412 {
    413 	static char buf[256];
    414 	char cc = '\0';
    415 	int precision, width1, width2, places;
    416 
    417 	if (equalize == 0)
    418 		return (default_format);
    419 
    420 	/* figure out "last" value printed */
    421 	if (first > last)
    422 		last = first - incr * floor((first - last) / incr);
    423 	else
    424 		last = first + incr * floor((last - first) / incr);
    425 
    426 	sprintf(buf, "%g", incr);
    427 	if (strchr(buf, 'e'))
    428 		cc = 'e';
    429 	precision = decimal_places(buf);
    430 
    431 	width1 = sprintf(buf, "%g", first);
    432 	if (strchr(buf, 'e'))
    433 		cc = 'e';
    434 	if ((places = decimal_places(buf)))
    435 		width1 -= (places + strlen(decimal_point));
    436 
    437 	precision = MAX(places, precision);
    438 
    439 	width2 = sprintf(buf, "%g", last);
    440 	if (strchr(buf, 'e'))
    441 		cc = 'e';
    442 	if ((places = decimal_places(buf)))
    443 		width2 -= (places + strlen(decimal_point));
    444 
    445 	if (precision) {
    446 		sprintf(buf, "%%%c%d.%d%c", pad,
    447 		    MAX(width1, width2) + (int) strlen(decimal_point) +
    448 		    precision, precision, (cc) ? cc : 'f');
    449 	} else {
    450 		sprintf(buf, "%%%c%d%c", pad, MAX(width1, width2),
    451 		    (cc) ? cc : 'g');
    452 	}
    453 
    454 	return (buf);
    455 }
    456