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seq.c revision 1.10 
      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 2017/10/29 01:28:46 ginsbach 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 = NULL;
     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 		for (; first <= last; first += incr) {
    175 			printf(fmt, first);
    176 			fputs(sep, stdout);
    177 		}
    178 	} else {
    179 		for (; first >= last; first += incr) {
    180 			printf(fmt, first);
    181 			fputs(sep, stdout);
    182 		}
    183 	}
    184 	if (term != NULL)
    185 		fputs(term, stdout);
    186 
    187 	return (0);
    188 }
    189 
    190 /*
    191  * numeric - verify that string is numeric
    192  */
    193 int
    194 numeric(const char *s)
    195 {
    196 	int seen_decimal_pt, decimal_pt_len;
    197 
    198 	/* skip any sign */
    199 	if (ISSIGN((unsigned char)*s))
    200 		s++;
    201 
    202 	seen_decimal_pt = 0;
    203 	decimal_pt_len = strlen(decimal_point);
    204 	while (*s) {
    205 		if (!isdigit((unsigned char)*s)) {
    206 			if (!seen_decimal_pt &&
    207 			    strncmp(s, decimal_point, decimal_pt_len) == 0) {
    208 				s += decimal_pt_len;
    209 				seen_decimal_pt = 1;
    210 				continue;
    211 			}
    212 			if (ISEXP((unsigned char)*s)) {
    213 				s++;
    214 				/* optional sign */
    215 				if (ISSIGN((unsigned char)*s))
    216 					s++;
    217 				continue;
    218 			}
    219 			break;
    220 		}
    221 		s++;
    222 	}
    223 	return (*s == '\0');
    224 }
    225 
    226 /*
    227  * valid_format - validate user specified format string
    228  */
    229 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 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 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 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 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