usr.bin/seq/seq.c

   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 }