src/seq.c

   1 /* seq - print sequence of numbers to standard output.
   2    Copyright (C) 1994-2010 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Ulrich Drepper.  */
  18
  19 #include <config.h>
  20 #include <getopt.h>
  21 #include <stdio.h>
  22 #include <sys/types.h>
  23
  24 #include "system.h"
  25 #include "c-strtod.h"
  26 #include "error.h"
  27 #include "quote.h"
  28 #include "xstrtod.h"
  29
  30 /* Roll our own isfinite rather than using <math.h>, so that we don't
  31    have to worry about linking -lm just for isfinite.  */
  32 #ifndef isfinite
  33 # define isfinite(x) ((x) * 0 == 0)
  34 #endif
  35
  36 /* The official name of this program (e.g., no `g' prefix).  */
  37 #define PROGRAM_NAME "seq"
  38
  39 #define AUTHORS proper_name ("Ulrich Drepper")
  40
  41 /* If true print all number with equal width.  */
  42 static bool equal_width;
  43
  44 /* The string used to separate two numbers.  */
  45 static char const *separator;
  46
  47 /* The string output after all numbers have been output.
  48    Usually "\n" or "\0".  */
  49 static char const terminator[] = "\n";
  50
  51 static struct option const long_options[] =
  52 {
  53   { "equal-width", no_argument, NULL, 'w'},
  54   { "format", required_argument, NULL, 'f'},
  55   { "separator", required_argument, NULL, 's'},
  56   {GETOPT_HELP_OPTION_DECL},
  57   {GETOPT_VERSION_OPTION_DECL},
  58   { NULL, 0, NULL, 0}
  59 };
  60
  61 void
  62 usage (int status)
  63 {
  64   if (status != EXIT_SUCCESS)
  65     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  66              program_name);
  67   else
  68     {
  69       printf (_("\
  70 Usage: %s [OPTION]... LAST\n\
  71   or:  %s [OPTION]... FIRST LAST\n\
  72   or:  %s [OPTION]... FIRST INCREMENT LAST\n\
  73 "), program_name, program_name, program_name);
  74       fputs (_("\
  75 Print numbers from FIRST to LAST, in steps of INCREMENT.\n\
  76 \n\
  77   -f, --format=FORMAT      use printf style floating-point FORMAT\n\
  78   -s, --separator=STRING   use STRING to separate numbers (default: \\n)\n\
  79   -w, --equal-width        equalize width by padding with leading zeroes\n\
  80 "), stdout);
  81       fputs (HELP_OPTION_DESCRIPTION, stdout);
  82       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  83       fputs (_("\
  84 \n\
  85 If FIRST or INCREMENT is omitted, it defaults to 1.  That is, an\n\
  86 omitted INCREMENT defaults to 1 even when LAST is smaller than FIRST.\n\
  87 FIRST, INCREMENT, and LAST are interpreted as floating point values.\n\
  88 INCREMENT is usually positive if FIRST is smaller than LAST, and\n\
  89 INCREMENT is usually negative if FIRST is greater than LAST.\n\
  90 "), stdout);
  91       fputs (_("\
  92 FORMAT must be suitable for printing one argument of type `double';\n\
  93 it defaults to %.PRECf if FIRST, INCREMENT, and LAST are all fixed point\n\
  94 decimal numbers with maximum precision PREC, and to %g otherwise.\n\
  95 "), stdout);
  96       emit_ancillary_info ();
  97     }
  98   exit (status);
  99 }
 100
 101 /* A command-line operand.  */
 102 struct operand
 103 {
 104   /* Its value, converted to 'long double'.  */
 105   long double value;
 106
 107   /* Its print width, if it were printed out in a form similar to its
 108      input form.  An input like "-.1" is treated like "-0.1", and an
 109      input like "1." is treated like "1", but otherwise widths are
 110      left alone.  */
 111   size_t width;
 112
 113   /* Number of digits after the decimal point, or INT_MAX if the
 114      number can't easily be expressed as a fixed-point number.  */
 115   int precision;
 116 };
 117 typedef struct operand operand;
 118
 119 /* Description of what a number-generating format will generate.  */
 120 struct layout
 121 {
 122   /* Number of bytes before and after the number.  */
 123   size_t prefix_len;
 124   size_t suffix_len;
 125 };
 126
 127 /* Read a long double value from the command line.
 128    Return if the string is correct else signal error.  */
 129
 130 static operand
 131 scan_arg (const char *arg)
 132 {
 133   operand ret;
 134
 135   if (! xstrtold (arg, NULL, &ret.value, c_strtold))
 136     {
 137       error (0, 0, _("invalid floating point argument: %s"), arg);
 138       usage (EXIT_FAILURE);
 139     }
 140
 141   /* We don't output spaces or '+' so don't include in width */
 142   while (isspace (to_uchar (*arg)) || *arg == '+')
 143     arg++;
 144
 145   ret.width = strlen (arg);
 146   ret.precision = INT_MAX;
 147
 148   if (! arg[strcspn (arg, "xX")] && isfinite (ret.value))
 149     {
 150       char const *decimal_point = strchr (arg, '.');
 151       if (! decimal_point)
 152         ret.precision = 0;
 153       else
 154         {
 155           size_t fraction_len = strcspn (decimal_point + 1, "eE");
 156           if (fraction_len <= INT_MAX)
 157             ret.precision = fraction_len;
 158           ret.width += (fraction_len == 0                      /* #.  -> #   */
 159                         ? -1
 160                         : (decimal_point == arg                /* .#  -> 0.# */
 161                            || ! ISDIGIT (decimal_point[-1]))); /* -.# -> 0.# */
 162         }
 163       char const *e = strchr (arg, 'e');
 164       if (! e)
 165         e = strchr (arg, 'E');
 166       if (e)
 167         {
 168           long exponent = strtol (e + 1, NULL, 10);
 169           ret.precision += exponent < 0 ? -exponent : 0;
 170         }
 171     }
 172
 173   return ret;
 174 }
 175
 176 /* If FORMAT is a valid printf format for a double argument, return
 177    its long double equivalent, allocated from dynamic storage, and
 178    store into *LAYOUT a description of the output layout; otherwise,
 179    report an error and exit.  */
 180
 181 static char const *
 182 long_double_format (char const *fmt, struct layout *layout)
 183 {
 184   size_t i;
 185   size_t prefix_len = 0;
 186   size_t suffix_len = 0;
 187   size_t length_modifier_offset;
 188   bool has_L;
 189
 190   for (i = 0; ! (fmt[i] == '%' && fmt[i + 1] != '%'); i += (fmt[i] == '%') + 1)
 191     {
 192       if (!fmt[i])
 193         error (EXIT_FAILURE, 0,
 194                _("format %s has no %% directive"), quote (fmt));
 195       prefix_len++;
 196     }
 197
 198   i++;
 199   i += strspn (fmt + i, "-+#0 '");
 200   i += strspn (fmt + i, "0123456789");
 201   if (fmt[i] == '.')
 202     {
 203       i++;
 204       i += strspn (fmt + i, "0123456789");
 205     }
 206
 207   length_modifier_offset = i;
 208   has_L = (fmt[i] == 'L');
 209   i += has_L;
 210   if (fmt[i] == '\0')
 211     error (EXIT_FAILURE, 0, _("format %s ends in %%"), quote (fmt));
 212   if (! strchr ("efgaEFGA", fmt[i]))
 213     error (EXIT_FAILURE, 0,
 214            _("format %s has unknown %%%c directive"), quote (fmt), fmt[i]);
 215
 216   for (i++; ; i += (fmt[i] == '%') + 1)
 217     if (fmt[i] == '%' && fmt[i + 1] != '%')
 218       error (EXIT_FAILURE, 0, _("format %s has too many %% directives"),
 219              quote (fmt));
 220     else if (fmt[i])
 221       suffix_len++;
 222     else
 223       {
 224         size_t format_size = i + 1;
 225         char *ldfmt = xmalloc (format_size + 1);
 226         memcpy (ldfmt, fmt, length_modifier_offset);
 227         ldfmt[length_modifier_offset] = 'L';
 228         strcpy (ldfmt + length_modifier_offset + 1,
 229                 fmt + length_modifier_offset + has_L);
 230         layout->prefix_len = prefix_len;
 231         layout->suffix_len = suffix_len;
 232         return ldfmt;
 233       }
 234 }
 235
 236 /* Actually print the sequence of numbers in the specified range, with the
 237    given or default stepping and format.  */
 238
 239 static void
 240 print_numbers (char const *fmt, struct layout layout,
 241                long double first, long double step, long double last)
 242 {
 243   bool out_of_range = (step < 0 ? first < last : last < first);
 244
 245   if (! out_of_range)
 246     {
 247       long double x = first;
 248       long double i;
 249
 250       for (i = 1; ; i++)
 251         {
 252           long double x0 = x;
 253           printf (fmt, x);
 254           if (out_of_range)
 255             break;
 256           x = first + i * step;
 257           out_of_range = (step < 0 ? x < last : last < x);
 258
 259           if (out_of_range)
 260             {
 261               /* If the number just past LAST prints as a value equal
 262                  to LAST, and prints differently from the previous
 263                  number, then print the number.  This avoids problems
 264                  with rounding.  For example, with the x86 it causes
 265                  "seq 0 0.000001 0.000003" to print 0.000003 instead
 266                  of stopping at 0.000002.  */
 267
 268               bool print_extra_number = false;
 269               long double x_val;
 270               char *x_str;
 271               int x_strlen;
 272               setlocale (LC_NUMERIC, "C");
 273               x_strlen = asprintf (&x_str, fmt, x);
 274               setlocale (LC_NUMERIC, "");
 275               if (x_strlen < 0)
 276                 xalloc_die ();
 277               x_str[x_strlen - layout.suffix_len] = '\0';
 278
 279               if (xstrtold (x_str + layout.prefix_len, NULL, &x_val, c_strtold)
 280                   && x_val == last)
 281                 {
 282                   char *x0_str = NULL;
 283                   if (asprintf (&x0_str, fmt, x0) < 0)
 284                     xalloc_die ();
 285                   print_extra_number = !STREQ (x0_str, x_str);
 286                   free (x0_str);
 287                 }
 288
 289               free (x_str);
 290               if (! print_extra_number)
 291                 break;
 292             }
 293
 294           fputs (separator, stdout);
 295         }
 296
 297       fputs (terminator, stdout);
 298     }
 299 }
 300
 301 /* Return the default format given FIRST, STEP, and LAST.  */
 302 static char const *
 303 get_default_format (operand first, operand step, operand last)
 304 {
 305   static char format_buf[sizeof "%0.Lf" + 2 * INT_STRLEN_BOUND (int)];
 306
 307   int prec = MAX (first.precision, step.precision);
 308
 309   if (prec != INT_MAX && last.precision != INT_MAX)
 310     {
 311       if (equal_width)
 312         {
 313           /* increase first_width by any increased precision in step */
 314           size_t first_width = first.width + (prec - first.precision);
 315           /* adjust last_width to use precision from first/step */
 316           size_t last_width = last.width + (prec - last.precision);
 317           if (last.precision && prec == 0)
 318             last_width--;  /* don't include space for '.' */
 319           if (last.precision == 0 && prec)
 320             last_width++;  /* include space for '.' */
 321           size_t width = MAX (first_width, last_width);
 322           if (width <= INT_MAX)
 323             {
 324               int w = width;
 325               sprintf (format_buf, "%%0%d.%dLf", w, prec);
 326               return format_buf;
 327             }
 328         }
 329       else
 330         {
 331           sprintf (format_buf, "%%.%dLf", prec);
 332           return format_buf;
 333         }
 334     }
 335
 336   return "%Lg";
 337 }
 338
 339 int
 340 main (int argc, char **argv)
 341 {
 342   int optc;
 343   operand first = { 1, 1, 0 };
 344   operand step = { 1, 1, 0 };
 345   operand last;
 346   struct layout layout = { 0, 0 };
 347
 348   /* The printf(3) format used for output.  */
 349   char const *format_str = NULL;
 350
 351   initialize_main (&argc, &argv);
 352   set_program_name (argv[0]);
 353   setlocale (LC_ALL, "");
 354   bindtextdomain (PACKAGE, LOCALEDIR);
 355   textdomain (PACKAGE);
 356
 357   atexit (close_stdout);
 358
 359   equal_width = false;
 360   separator = "\n";
 361
 362   /* We have to handle negative numbers in the command line but this
 363      conflicts with the command line arguments.  So explicitly check first
 364      whether the next argument looks like a negative number.  */
 365   while (optind < argc)
 366     {
 367       if (argv[optind][0] == '-'
 368           && ((optc = argv[optind][1]) == '.' || ISDIGIT (optc)))
 369         {
 370           /* means negative number */
 371           break;
 372         }
 373
 374       optc = getopt_long (argc, argv, "+f:s:w", long_options, NULL);
 375       if (optc == -1)
 376         break;
 377
 378       switch (optc)
 379         {
 380         case 'f':
 381           format_str = optarg;
 382           break;
 383
 384         case 's':
 385           separator = optarg;
 386           break;
 387
 388         case 'w':
 389           equal_width = true;
 390           break;
 391
 392         case_GETOPT_HELP_CHAR;
 393
 394         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 395
 396         default:
 397           usage (EXIT_FAILURE);
 398         }
 399     }
 400
 401   if (argc - optind < 1)
 402     {
 403       error (0, 0, _("missing operand"));
 404       usage (EXIT_FAILURE);
 405     }
 406
 407   if (3 < argc - optind)
 408     {
 409       error (0, 0, _("extra operand %s"), quote (argv[optind + 3]));
 410       usage (EXIT_FAILURE);
 411     }
 412
 413   if (format_str)
 414     format_str = long_double_format (format_str, &layout);
 415
 416   last = scan_arg (argv[optind++]);
 417
 418   if (optind < argc)
 419     {
 420       first = last;
 421       last = scan_arg (argv[optind++]);
 422
 423       if (optind < argc)
 424         {
 425           step = last;
 426           last = scan_arg (argv[optind++]);
 427         }
 428     }
 429
 430   if (format_str != NULL && equal_width)
 431     {
 432       error (0, 0, _("\
 433 format string may not be specified when printing equal width strings"));
 434       usage (EXIT_FAILURE);
 435     }
 436
 437   if (format_str == NULL)
 438     format_str = get_default_format (first, step, last);
 439
 440   print_numbers (format_str, layout, first.value, step.value, last.value);
 441
 442   exit (EXIT_SUCCESS);
 443 }