1 /* $OpenBSD: seq.c,v 1.6 2022/02/25 16:00:39 tb Exp $ */ 2 3 /*- 4 * Copyright (c) 2005 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Brian Ginsbach. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <ctype.h> 33 #include <err.h> 34 #include <errno.h> 35 #include <getopt.h> 36 #include <math.h> 37 #include <locale.h> 38 #include <stdio.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #include <unistd.h> 42 43 #define VERSION "1.0" 44 #define ZERO '0' 45 #define SPACE ' ' 46 47 #define MAXIMUM(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 static const struct option long_opts[] = { 58 {"format", required_argument, NULL, 'f'}, 59 {"help", no_argument, NULL, 'h'}, 60 {"separator", required_argument, NULL, 's'}, 61 {"version", no_argument, NULL, 'v'}, 62 {"equal-width", no_argument, NULL, 'w'}, 63 {NULL, no_argument, NULL, 0} 64 }; 65 66 /* Prototypes */ 67 68 static double e_atof(const char *); 69 70 static int decimal_places(const char *); 71 static int numeric(const char *); 72 static int valid_format(const char *); 73 74 static char *generate_format(double, double, double, int, char); 75 76 static __dead void usage(int error); 77 78 /* 79 * The seq command will print out a numeric sequence from 1, the default, 80 * to a user specified upper limit by 1. The lower bound and increment 81 * maybe indicated by the user on the command line. The sequence can 82 * be either whole, the default, or decimal numbers. 83 */ 84 int 85 main(int argc, char *argv[]) 86 { 87 int c = 0; 88 int equalize = 0; 89 double first = 1.0; 90 double last = 0.0; 91 double incr = 0.0; 92 double last_shown_value = 0.0; 93 double cur, step; 94 struct lconv *locale; 95 char *fmt = NULL; 96 const char *sep = "\n"; 97 const char *term = "\n"; 98 char *cur_print, *last_print; 99 char pad = ZERO; 100 101 if (pledge("stdio", NULL) == -1) 102 err(1, "pledge"); 103 104 /* Determine the locale's decimal point. */ 105 locale = localeconv(); 106 if (locale && locale->decimal_point && locale->decimal_point[0] != '\0') 107 decimal_point = locale->decimal_point; 108 109 /* 110 * Process options, but handle negative numbers separately 111 * least they trip up getopt(3). 112 */ 113 while ((optind < argc) && !numeric(argv[optind]) && 114 (c = getopt_long(argc, argv, "+f:s:w", long_opts, NULL)) != -1) { 115 116 switch (c) { 117 case 'f': /* format (plan9/GNU) */ 118 fmt = optarg; 119 equalize = 0; 120 break; 121 case 's': /* separator (GNU) */ 122 sep = optarg; 123 break; 124 case 'v': /* version (GNU) */ 125 printf("seq version %s\n", VERSION); 126 return 0; 127 case 'w': /* equal width (plan9/GNU) */ 128 if (fmt == NULL) { 129 if (equalize++) 130 pad = SPACE; 131 } 132 break; 133 case 'h': /* help (GNU) */ 134 usage(0); 135 break; 136 default: 137 usage(1); 138 break; 139 } 140 } 141 142 argc -= optind; 143 argv += optind; 144 if (argc < 1 || argc > 3) 145 usage(1); 146 147 last = e_atof(argv[argc - 1]); 148 149 if (argc > 1) 150 first = e_atof(argv[0]); 151 152 if (argc > 2) { 153 incr = e_atof(argv[1]); 154 /* Plan 9/GNU don't do zero */ 155 if (incr == 0.0) 156 errx(1, "zero %screment", (first < last) ? "in" : "de"); 157 } 158 159 /* default is one for Plan 9/GNU work alike */ 160 if (incr == 0.0) 161 incr = (first < last) ? 1.0 : -1.0; 162 163 if (incr <= 0.0 && first < last) 164 errx(1, "needs positive increment"); 165 166 if (incr >= 0.0 && first > last) 167 errx(1, "needs negative decrement"); 168 169 if (fmt != NULL) { 170 if (!valid_format(fmt)) 171 errx(1, "invalid format string: `%s'", fmt); 172 /* 173 * XXX to be bug for bug compatible with Plan 9 add a 174 * newline if none found at the end of the format string. 175 */ 176 } else 177 fmt = generate_format(first, incr, last, equalize, pad); 178 179 for (step = 1, cur = first; incr > 0 ? cur <= last : cur >= last; 180 cur = first + incr * step++) { 181 if (cur != first) 182 fputs(sep, stdout); 183 printf(fmt, cur); 184 last_shown_value = cur; 185 } 186 187 /* 188 * Did we miss the last value of the range in the loop above? 189 * 190 * We might have, so check if the printable version of the last 191 * computed value ('cur') and desired 'last' value are equal. If they 192 * are equal after formatting truncation, but 'cur' and 193 * 'last_shown_value' are not equal, it means the exit condition of the 194 * loop held true due to a rounding error and we still need to print 195 * 'last'. 196 */ 197 if (asprintf(&cur_print, fmt, cur) == -1 || 198 asprintf(&last_print, fmt, last) == -1) 199 err(1, "asprintf"); 200 if (strcmp(cur_print, last_print) == 0 && cur != last_shown_value) { 201 if (cur != first) 202 fputs(sep, stdout); 203 fputs(last_print, stdout); 204 } 205 free(cur_print); 206 free(last_print); 207 208 fputs(term, stdout); 209 210 return 0; 211 } 212 213 /* 214 * numeric - verify that string is numeric 215 */ 216 static int 217 numeric(const char *s) 218 { 219 int seen_decimal_pt, decimal_pt_len; 220 221 /* skip any sign */ 222 if (ISSIGN((unsigned char)*s)) 223 s++; 224 225 seen_decimal_pt = 0; 226 decimal_pt_len = strlen(decimal_point); 227 while (*s) { 228 if (!isdigit((unsigned char)*s)) { 229 if (!seen_decimal_pt && 230 strncmp(s, decimal_point, decimal_pt_len) == 0) { 231 s += decimal_pt_len; 232 seen_decimal_pt = 1; 233 continue; 234 } 235 if (ISEXP((unsigned char)*s)) { 236 s++; 237 if (ISSIGN((unsigned char)*s) || 238 isdigit((unsigned char)*s)) { 239 s++; 240 continue; 241 } 242 } 243 break; 244 } 245 s++; 246 } 247 return *s == '\0'; 248 } 249 250 /* 251 * valid_format - validate user specified format string 252 */ 253 static int 254 valid_format(const char *fmt) 255 { 256 unsigned conversions = 0; 257 258 while (*fmt != '\0') { 259 /* scan for conversions */ 260 if (*fmt != '%') { 261 fmt++; 262 continue; 263 } 264 fmt++; 265 266 /* allow %% but not things like %10% */ 267 if (*fmt == '%') { 268 fmt++; 269 continue; 270 } 271 272 /* flags */ 273 while (*fmt != '\0' && strchr("#0- +'", *fmt)) { 274 fmt++; 275 } 276 277 /* field width */ 278 while (*fmt != '\0' && strchr("0123456789", *fmt)) { 279 fmt++; 280 } 281 282 /* precision */ 283 if (*fmt == '.') { 284 fmt++; 285 while (*fmt != '\0' && strchr("0123456789", *fmt)) { 286 fmt++; 287 } 288 } 289 290 /* conversion */ 291 switch (*fmt) { 292 case 'A': 293 case 'a': 294 case 'E': 295 case 'e': 296 case 'F': 297 case 'f': 298 case 'G': 299 case 'g': 300 /* floating point formats are accepted */ 301 conversions++; 302 break; 303 default: 304 /* anything else is not */ 305 return 0; 306 } 307 } 308 309 /* PR 236347 -- user format strings must have a conversion */ 310 return conversions == 1; 311 } 312 313 /* 314 * e_atof - convert an ASCII string to a double 315 * exit if string is not a valid double, or if converted value would 316 * cause overflow or underflow 317 */ 318 static double 319 e_atof(const char *num) 320 { 321 char *endp; 322 double dbl; 323 324 errno = 0; 325 dbl = strtod(num, &endp); 326 327 if (errno == ERANGE) 328 /* under or overflow */ 329 err(2, "%s", num); 330 else if (*endp != '\0') 331 /* "junk" left in number */ 332 errx(2, "invalid floating point argument: %s", num); 333 334 /* zero shall have no sign */ 335 if (dbl == -0.0) 336 dbl = 0; 337 return dbl; 338 } 339 340 /* 341 * decimal_places - count decimal places in a number (string) 342 */ 343 static int 344 decimal_places(const char *number) 345 { 346 int places = 0; 347 char *dp; 348 349 /* look for a decimal point */ 350 if ((dp = strstr(number, decimal_point))) { 351 dp += strlen(decimal_point); 352 353 while (isdigit((unsigned char)*dp++)) 354 places++; 355 } 356 return places; 357 } 358 359 /* 360 * generate_format - create a format string 361 * 362 * XXX to be bug for bug compatible with Plan9 and GNU return "%g" 363 * when "%g" prints as "%e" (this way no width adjustments are made) 364 */ 365 static char * 366 generate_format(double first, double incr, double last, int equalize, char pad) 367 { 368 static char buf[256]; 369 char cc = '\0'; 370 int precision, width1, width2, places; 371 372 if (equalize == 0) 373 return default_format; 374 375 /* figure out "last" value printed */ 376 if (first > last) 377 last = first - incr * floor((first - last) / incr); 378 else 379 last = first + incr * floor((last - first) / incr); 380 381 snprintf(buf, sizeof(buf), "%g", incr); 382 if (strchr(buf, 'e')) 383 cc = 'e'; 384 precision = decimal_places(buf); 385 386 width1 = snprintf(buf, sizeof(buf), "%g", first); 387 if (strchr(buf, 'e')) 388 cc = 'e'; 389 if ((places = decimal_places(buf))) 390 width1 -= (places + strlen(decimal_point)); 391 392 precision = MAXIMUM(places, precision); 393 394 width2 = snprintf(buf, sizeof(buf), "%g", last); 395 if (strchr(buf, 'e')) 396 cc = 'e'; 397 if ((places = decimal_places(buf))) 398 width2 -= (places + strlen(decimal_point)); 399 400 /* XXX if incr is floating point fix the precision */ 401 if (precision) { 402 snprintf(buf, sizeof(buf), "%%%c%d.%d%c", pad, 403 MAXIMUM(width1, width2) + (int)strlen(decimal_point) + 404 precision, precision, (cc) ? cc : 'f'); 405 } else { 406 snprintf(buf, sizeof(buf), "%%%c%d%c", pad, 407 MAXIMUM(width1, width2), (cc) ? cc : 'g'); 408 } 409 410 return buf; 411 } 412 413 static __dead void 414 usage(int error) 415 { 416 fprintf(stderr, 417 "usage: %s [-w] [-f format] [-s string] [first [incr]] last\n", 418 getprogname()); 419 exit(error); 420 } 421