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seq.c revision 1.10.4.1 
      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 1.10.4.1 2019/06/10 22:10:24 christos 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 numeric(const char *);
     66 int valid_format(const char *);
     67 
     68 char *generate_format(double, double, double, int, char);
     69 char *unescape(char *);
     70 
     71 /*
     72  * The seq command will print out a numeric sequence from 1, the default,
     73  * to a user specified upper limit by 1.  The lower bound and increment
     74  * maybe indicated by the user on the command line.  The sequence can
     75  * be either whole, the default, or decimal numbers.
     76  */
     77 int
     78 main(int argc, char *argv[])
     79 {
     80 	int c = 0, errflg = 0;
     81 	int equalize = 0;
     82 	double first = 1.0;
     83 	double last = 0.0;
     84 	double incr = 0.0;
     85 	struct lconv *locale;
     86 	char *fmt = NULL;
     87 	const char *sep = "\n";
     88 	const char *term = "\n";
     89 	char pad = ZERO;
     90 
     91 	/* Determine the locale's decimal point. */
     92 	locale = localeconv();
     93 	if (locale && locale->decimal_point && locale->decimal_point[0] != '\0')
     94 		decimal_point = locale->decimal_point;
     95 
     96 	/*
     97          * Process options, but handle negative numbers separately
     98          * least they trip up getopt(3).
     99          */
    100 	while ((optind < argc) && !numeric(argv[optind]) &&
    101 	    (c = getopt(argc, argv, "f:hs:t:w")) != -1) {
    102 
    103 		switch (c) {
    104 		case 'f':	/* format (plan9) */
    105 			fmt = optarg;
    106 			equalize = 0;
    107 			break;
    108 		case 's':	/* separator (GNU) */
    109 			sep = unescape(optarg);
    110 			break;
    111 		case 't':	/* terminator (new) */
    112 			term = unescape(optarg);
    113 			break;
    114 		case 'w':	/* equal width (plan9) */
    115 			if (!fmt)
    116 				if (equalize++)
    117 					pad = SPACE;
    118 			break;
    119 		case 'h':	/* help (GNU) */
    120 		default:
    121 			errflg++;
    122 			break;
    123 		}
    124 	}
    125 
    126 	argc -= optind;
    127 	argv += optind;
    128 	if (argc < 1 || argc > 3)
    129 		errflg++;
    130 
    131 	if (errflg) {
    132 		fprintf(stderr,
    133 		    "usage: %s [-w] [-f format] [-s string] [-t string] [first [incr]] last\n",
    134 		    getprogname());
    135 		exit(1);
    136 	}
    137 
    138 	last = e_atof(argv[argc - 1]);
    139 
    140 	if (argc > 1)
    141 		first = e_atof(argv[0]);
    142 
    143 	if (argc > 2) {
    144 		incr = e_atof(argv[1]);
    145 		/* Plan 9/GNU don't do zero */
    146 		if (incr == 0.0)
    147 			errx(1, "zero %screment", (first < last)? "in" : "de");
    148 	}
    149 
    150 	/* default is one for Plan 9/GNU work alike */
    151 	if (incr == 0.0)
    152 		incr = (first < last) ? 1.0 : -1.0;
    153 
    154 	if (incr <= 0.0 && first < last)
    155 		errx(1, "needs positive increment");
    156 
    157 	if (incr >= 0.0 && first > last)
    158 		errx(1, "needs negative decrement");
    159 
    160 	if (fmt != NULL) {
    161 		if (!valid_format(fmt))
    162 			errx(1, "invalid format string: `%s'", fmt);
    163 		fmt = unescape(fmt);
    164 		if (!valid_format(fmt))
    165 			errx(1, "invalid format string");
    166 		/*
    167 	         * XXX to be bug for bug compatible with Plan 9 add a
    168 		 * newline if none found at the end of the format string.
    169 		 */
    170 	} else
    171 		fmt = generate_format(first, incr, last, equalize, pad);
    172 
    173 	if (incr > 0) {
    174 		printf(fmt, first);
    175 		for (first += incr; first <= last; first += incr) {
    176 			fputs(sep, stdout);
    177 			printf(fmt, first);
    178 		}
    179 	} else {
    180 		printf(fmt, first);
    181 		for (first += incr; first >= last; first += incr) {
    182 			fputs(sep, stdout);
    183 			printf(fmt, first);
    184 		}
    185 	}
    186 	if (term != NULL)
    187 		fputs(term, stdout);
    188 
    189 	return (0);
    190 }
    191 
    192 /*
    193  * numeric - verify that string is numeric
    194  */
    195 int
    196 numeric(const char *s)
    197 {
    198 	int seen_decimal_pt, decimal_pt_len;
    199 
    200 	/* skip any sign */
    201 	if (ISSIGN((unsigned char)*s))
    202 		s++;
    203 
    204 	seen_decimal_pt = 0;
    205 	decimal_pt_len = strlen(decimal_point);
    206 	while (*s) {
    207 		if (!isdigit((unsigned char)*s)) {
    208 			if (!seen_decimal_pt &&
    209 			    strncmp(s, decimal_point, decimal_pt_len) == 0) {
    210 				s += decimal_pt_len;
    211 				seen_decimal_pt = 1;
    212 				continue;
    213 			}
    214 			if (ISEXP((unsigned char)*s)) {
    215 				s++;
    216 				/* optional sign */
    217 				if (ISSIGN((unsigned char)*s))
    218 					s++;
    219 				continue;
    220 			}
    221 			break;
    222 		}
    223 		s++;
    224 	}
    225 	return (*s == '\0');
    226 }
    227 
    228 /*
    229  * valid_format - validate user specified format string
    230  */
    231 int
    232 valid_format(const char *fmt)
    233 {
    234 	unsigned conversions = 0;
    235 
    236 	while (*fmt != '\0') {
    237 		/* scan for conversions */
    238 		if (*fmt != '%') {
    239 			fmt++;
    240 			continue;
    241 		}
    242 		fmt++;
    243 
    244 		/* allow %% but not things like %10% */
    245 		if (*fmt == '%') {
    246 			fmt++;
    247 			continue;
    248 		}
    249 
    250 		/* flags */
    251 		while (*fmt != '\0' && strchr("#0- +'", *fmt)) {
    252 			fmt++;
    253 		}
    254 
    255 		/* field width */
    256 		while (*fmt != '\0' && strchr("0123456789", *fmt)) {
    257 			fmt++;
    258 		}
    259 
    260 		/* precision */
    261 		if (*fmt == '.') {
    262 			fmt++;
    263 			while (*fmt != '\0' && strchr("0123456789", *fmt)) {
    264 				fmt++;
    265 			}
    266 		}
    267 
    268 		/* conversion */
    269 		switch (*fmt) {
    270 		    case 'A':
    271 		    case 'a':
    272 		    case 'E':
    273 		    case 'e':
    274 		    case 'F':
    275 		    case 'f':
    276 		    case 'G':
    277 		    case 'g':
    278 			/* floating point formats are accepted */
    279 			conversions++;
    280 			break;
    281 		    default:
    282 			/* anything else is not */
    283 			return 0;
    284 		}
    285 	}
    286 
    287 	return (conversions <= 1);
    288 }
    289 
    290 /*
    291  * unescape - handle C escapes in a string
    292  */
    293 char *
    294 unescape(char *orig)
    295 {
    296 	char c, *cp, *new = orig;
    297 	int i;
    298 
    299 	for (cp = orig; (*orig = *cp); cp++, orig++) {
    300 		if (*cp != '\\')
    301 			continue;
    302 
    303 		switch (*++cp) {
    304 		case 'a':	/* alert (bell) */
    305 			*orig = '\a';
    306 			continue;
    307 		case 'b':	/* backspace */
    308 			*orig = '\b';
    309 			continue;
    310 		case 'e':	/* escape */
    311 			*orig = '\e';
    312 			continue;
    313 		case 'f':	/* formfeed */
    314 			*orig = '\f';
    315 			continue;
    316 		case 'n':	/* newline */
    317 			*orig = '\n';
    318 			continue;
    319 		case 'r':	/* carriage return */
    320 			*orig = '\r';
    321 			continue;
    322 		case 't':	/* horizontal tab */
    323 			*orig = '\t';
    324 			continue;
    325 		case 'v':	/* vertical tab */
    326 			*orig = '\v';
    327 			continue;
    328 		case '\\':	/* backslash */
    329 			*orig = '\\';
    330 			continue;
    331 		case '\'':	/* single quote */
    332 			*orig = '\'';
    333 			continue;
    334 		case '\"':	/* double quote */
    335 			*orig = '"';
    336 			continue;
    337 		case '0':
    338 		case '1':
    339 		case '2':
    340 		case '3':	/* octal */
    341 		case '4':
    342 		case '5':
    343 		case '6':
    344 		case '7':	/* number */
    345 			for (i = 0, c = 0;
    346 			     ISODIGIT((unsigned char)*cp) && i < 3;
    347 			     i++, cp++) {
    348 				c <<= 3;
    349 				c |= (*cp - '0');
    350 			}
    351 			*orig = c;
    352 			--cp;
    353 			continue;
    354 		case 'x':	/* hexadecimal number */
    355 			cp++;	/* skip 'x' */
    356 			for (i = 0, c = 0;
    357 			     isxdigit((unsigned char)*cp) && i < 2;
    358 			     i++, cp++) {
    359 				c <<= 4;
    360 				if (isdigit((unsigned char)*cp))
    361 					c |= (*cp - '0');
    362 				else
    363 					c |= ((toupper((unsigned char)*cp) -
    364 					    'A') + 10);
    365 			}
    366 			*orig = c;
    367 			--cp;
    368 			continue;
    369 		default:
    370 			--cp;
    371 			break;
    372 		}
    373 	}
    374 
    375 	return (new);
    376 }
    377 
    378 /*
    379  * e_atof - convert an ASCII string to a double
    380  *	exit if string is not a valid double, or if converted value would
    381  *	cause overflow or underflow
    382  */
    383 double
    384 e_atof(const char *num)
    385 {
    386 	char *endp;
    387 	double dbl;
    388 
    389 	errno = 0;
    390 	dbl = strtod(num, &endp);
    391 
    392 	if (errno == ERANGE)
    393 		/* under or overflow */
    394 		err(2, "%s", num);
    395 	else if (*endp != '\0')
    396 		/* "junk" left in number */
    397 		errx(2, "invalid floating point argument: %s", num);
    398 
    399 	/* zero shall have no sign */
    400 	if (dbl == -0.0)
    401 		dbl = 0;
    402 	return (dbl);
    403 }
    404 
    405 /*
    406  * decimal_places - count decimal places in a number (string)
    407  */
    408 int
    409 decimal_places(const char *number)
    410 {
    411 	int places = 0;
    412 	char *dp;
    413 
    414 	/* look for a decimal point */
    415 	if ((dp = strstr(number, decimal_point))) {
    416 		dp += strlen(decimal_point);
    417 
    418 		while (isdigit((unsigned char)*dp++))
    419 			places++;
    420 	}
    421 	return (places);
    422 }
    423 
    424 /*
    425  * generate_format - create a format string
    426  *
    427  * XXX to be bug for bug compatible with Plan9 and GNU return "%g"
    428  * when "%g" prints as "%e" (this way no width adjustments are made)
    429  */
    430 char *
    431 generate_format(double first, double incr, double last, int equalize, char pad)
    432 {
    433 	static char buf[256];
    434 	char cc = '\0';
    435 	int precision, width1, width2, places;
    436 
    437 	if (equalize == 0)
    438 		return (default_format);
    439 
    440 	/* figure out "last" value printed */
    441 	if (first > last)
    442 		last = first - incr * floor((first - last) / incr);
    443 	else
    444 		last = first + incr * floor((last - first) / incr);
    445 
    446 	sprintf(buf, "%g", incr);
    447 	if (strchr(buf, 'e'))
    448 		cc = 'e';
    449 	precision = decimal_places(buf);
    450 
    451 	width1 = sprintf(buf, "%g", first);
    452 	if (strchr(buf, 'e'))
    453 		cc = 'e';
    454 	if ((places = decimal_places(buf)))
    455 		width1 -= (places + strlen(decimal_point));
    456 
    457 	precision = MAX(places, precision);
    458 
    459 	width2 = sprintf(buf, "%g", last);
    460 	if (strchr(buf, 'e'))
    461 		cc = 'e';
    462 	if ((places = decimal_places(buf)))
    463 		width2 -= (places + strlen(decimal_point));
    464 
    465 	if (precision) {
    466 		sprintf(buf, "%%%c%d.%d%c", pad,
    467 		    MAX(width1, width2) + (int) strlen(decimal_point) +
    468 		    precision, precision, (cc) ? cc : 'f');
    469 	} else {
    470 		sprintf(buf, "%%%c%d%c", pad, MAX(width1, width2),
    471 		    (cc) ? cc : 'g');
    472 	}
    473 
    474 	return (buf);
    475 }
    476