src/seq.c

   1 /* seq - print sequence of numbers to standard output.
   2    Copyright (C) 1994-2012 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     emit_try_help ();
  66   else
  67     {
  68       printf (_("\
  69 Usage: %s [OPTION]... LAST\n\
  70   or:  %s [OPTION]... FIRST LAST\n\
  71   or:  %s [OPTION]... FIRST INCREMENT LAST\n\
  72 "), program_name, program_name, program_name);
  73       fputs (_("\
  74 Print numbers from FIRST to LAST, in steps of INCREMENT.\n\
  75 \n\
  76   -f, --format=FORMAT      use printf style floating-point FORMAT\n\
  77   -s, --separator=STRING   use STRING to separate numbers (default: \\n)\n\
  78   -w, --equal-width        equalize width by padding with leading zeroes\n\
  79 "), stdout);
  80       fputs (HELP_OPTION_DESCRIPTION, stdout);
  81       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  82       fputs (_("\
  83 \n\
  84 If FIRST or INCREMENT is omitted, it defaults to 1.  That is, an\n\
  85 omitted INCREMENT defaults to 1 even when LAST is smaller than FIRST.\n\
  86 FIRST, INCREMENT, and LAST are interpreted as floating point values.\n\
  87 INCREMENT is usually positive if FIRST is smaller than LAST, and\n\
  88 INCREMENT is usually negative if FIRST is greater than LAST.\n\
  89 "), stdout);
  90       fputs (_("\
  91 FORMAT must be suitable for printing one argument of type 'double';\n\
  92 it defaults to %.PRECf if FIRST, INCREMENT, and LAST are all fixed point\n\
  93 decimal numbers with maximum precision PREC, and to %g otherwise.\n\
  94 "), stdout);
  95       emit_ancillary_info ();
  96     }
  97   exit (status);
  98 }
  99
 100 /* A command-line operand.  */
 101 struct operand
 102 {
 103   /* Its value, converted to 'long double'.  */
 104   long double value;
 105
 106   /* Its print width, if it were printed out in a form similar to its
 107      input form.  An input like "-.1" is treated like "-0.1", and an
 108      input like "1." is treated like "1", but otherwise widths are
 109      left alone.  */
 110   size_t width;
 111
 112   /* Number of digits after the decimal point, or INT_MAX if the
 113      number can't easily be expressed as a fixed-point number.  */
 114   int precision;
 115 };
 116 typedef struct operand operand;
 117
 118 /* Description of what a number-generating format will generate.  */
 119 struct layout
 120 {
 121   /* Number of bytes before and after the number.  */
 122   size_t prefix_len;
 123   size_t suffix_len;
 124 };
 125
 126 /* Read a long double value from the command line.
 127    Return if the string is correct else signal error.  */
 128
 129 static operand
 130 scan_arg (const char *arg)
 131 {
 132   operand ret;
 133
 134   if (! xstrtold (arg, NULL, &ret.value, c_strtold))
 135     {
 136       error (0, 0, _("invalid floating point argument: %s"), arg);
 137       usage (EXIT_FAILURE);
 138     }
 139
 140   /* We don't output spaces or '+' so don't include in width */
 141   while (isspace (to_uchar (*arg)) || *arg == '+')
 142     arg++;
 143
 144   ret.width = strlen (arg);
 145   ret.precision = INT_MAX;
 146
 147   if (! arg[strcspn (arg, "xX")] && isfinite (ret.value))
 148     {
 149       char const *decimal_point = strchr (arg, '.');
 150       if (! decimal_point)
 151         ret.precision = 0;
 152       else
 153         {
 154           size_t fraction_len = strcspn (decimal_point + 1, "eE");
 155           if (fraction_len <= INT_MAX)
 156             ret.precision = fraction_len;
 157           ret.width += (fraction_len == 0                      /* #.  -> #   */
 158                         ? -1
 159                         : (decimal_point == arg                /* .#  -> 0.# */
 160                            || ! ISDIGIT (decimal_point[-1]))); /* -.# -> 0.# */
 161         }
 162       char const *e = strchr (arg, 'e');
 163       if (! e)
 164         e = strchr (arg, 'E');
 165       if (e)
 166         {
 167           long exponent = strtol (e + 1, NULL, 10);
 168           ret.precision += exponent < 0 ? -exponent : 0;
 169         }
 170     }
 171
 172   return ret;
 173 }
 174
 175 /* If FORMAT is a valid printf format for a double argument, return
 176    its long double equivalent, allocated from dynamic storage, and
 177    store into *LAYOUT a description of the output layout; otherwise,
 178    report an error and exit.  */
 179
 180 static char const *
 181 long_double_format (char const *fmt, struct layout *layout)
 182 {
 183   size_t i;
 184   size_t prefix_len = 0;
 185   size_t suffix_len = 0;
 186   size_t length_modifier_offset;
 187   bool has_L;
 188
 189   for (i = 0; ! (fmt[i] == '%' && fmt[i + 1] != '%'); i += (fmt[i] == '%') + 1)
 190     {
 191       if (!fmt[i])
 192         error (EXIT_FAILURE, 0,
 193                _("format %s has no %% directive"), quote (fmt));
 194       prefix_len++;
 195     }
 196
 197   i++;
 198   i += strspn (fmt + i, "-+#0 '");
 199   i += strspn (fmt + i, "0123456789");
 200   if (fmt[i] == '.')
 201     {
 202       i++;
 203       i += strspn (fmt + i, "0123456789");
 204     }
 205
 206   length_modifier_offset = i;
 207   has_L = (fmt[i] == 'L');
 208   i += has_L;
 209   if (fmt[i] == '\0')
 210     error (EXIT_FAILURE, 0, _("format %s ends in %%"), quote (fmt));
 211   if (! strchr ("efgaEFGA", fmt[i]))
 212     error (EXIT_FAILURE, 0,
 213            _("format %s has unknown %%%c directive"), quote (fmt), fmt[i]);
 214
 215   for (i++; ; i += (fmt[i] == '%') + 1)
 216     if (fmt[i] == '%' && fmt[i + 1] != '%')
 217       error (EXIT_FAILURE, 0, _("format %s has too many %% directives"),
 218              quote (fmt));
 219     else if (fmt[i])
 220       suffix_len++;
 221     else
 222       {
 223         size_t format_size = i + 1;
 224         char *ldfmt = xmalloc (format_size + 1);
 225         memcpy (ldfmt, fmt, length_modifier_offset);
 226         ldfmt[length_modifier_offset] = 'L';
 227         strcpy (ldfmt + length_modifier_offset + 1,
 228                 fmt + length_modifier_offset + has_L);
 229         layout->prefix_len = prefix_len;
 230         layout->suffix_len = suffix_len;
 231         return ldfmt;
 232       }
 233 }
 234
 235 /* Actually print the sequence of numbers in the specified range, with the
 236    given or default stepping and format.  */
 237
 238 static void
 239 print_numbers (char const *fmt, struct layout layout,
 240                long double first, long double step, long double last)
 241 {
 242   bool out_of_range = (step < 0 ? first < last : last < first);
 243
 244   if (! out_of_range)
 245     {
 246       long double x = first;
 247       long double i;
 248
 249       for (i = 1; ; i++)
 250         {
 251           long double x0 = x;
 252           printf (fmt, x);
 253           if (out_of_range)
 254             break;
 255           x = first + i * step;
 256           out_of_range = (step < 0 ? x < last : last < x);
 257
 258           if (out_of_range)
 259             {
 260               /* If the number just past LAST prints as a value equal
 261                  to LAST, and prints differently from the previous
 262                  number, then print the number.  This avoids problems
 263                  with rounding.  For example, with the x86 it causes
 264                  "seq 0 0.000001 0.000003" to print 0.000003 instead
 265                  of stopping at 0.000002.  */
 266
 267               bool print_extra_number = false;
 268               long double x_val;
 269               char *x_str;
 270               int x_strlen;
 271               setlocale (LC_NUMERIC, "C");
 272               x_strlen = asprintf (&x_str, fmt, x);
 273               setlocale (LC_NUMERIC, "");
 274               if (x_strlen < 0)
 275                 xalloc_die ();
 276               x_str[x_strlen - layout.suffix_len] = '\0';
 277
 278               if (xstrtold (x_str + layout.prefix_len, NULL, &x_val, c_strtold)
 279                   && x_val == last)
 280                 {
 281                   char *x0_str = NULL;
 282                   if (asprintf (&x0_str, fmt, x0) < 0)
 283                     xalloc_die ();
 284                   print_extra_number = !STREQ (x0_str, x_str);
 285                   free (x0_str);
 286                 }
 287
 288               free (x_str);
 289               if (! print_extra_number)
 290                 break;
 291             }
 292
 293           fputs (separator, stdout);
 294         }
 295
 296       fputs (terminator, stdout);
 297     }
 298 }
 299
 300 /* Return the default format given FIRST, STEP, and LAST.  */
 301 static char const *
 302 get_default_format (operand first, operand step, operand last)
 303 {
 304   static char format_buf[sizeof "%0.Lf" + 2 * INT_STRLEN_BOUND (int)];
 305
 306   int prec = MAX (first.precision, step.precision);
 307
 308   if (prec != INT_MAX && last.precision != INT_MAX)
 309     {
 310       if (equal_width)
 311         {
 312           /* increase first_width by any increased precision in step */
 313           size_t first_width = first.width + (prec - first.precision);
 314           /* adjust last_width to use precision from first/step */
 315           size_t last_width = last.width + (prec - last.precision);
 316           if (last.precision && prec == 0)
 317             last_width--;  /* don't include space for '.' */
 318           if (last.precision == 0 && prec)
 319             last_width++;  /* include space for '.' */
 320           size_t width = MAX (first_width, last_width);
 321           if (width <= INT_MAX)
 322             {
 323               int w = width;
 324               sprintf (format_buf, "%%0%d.%dLf", w, prec);
 325               return format_buf;
 326             }
 327         }
 328       else
 329         {
 330           sprintf (format_buf, "%%.%dLf", prec);
 331           return format_buf;
 332         }
 333     }
 334
 335   return "%Lg";
 336 }
 337
 338 int
 339 main (int argc, char **argv)
 340 {
 341   int optc;
 342   operand first = { 1, 1, 0 };
 343   operand step = { 1, 1, 0 };
 344   operand last;
 345   struct layout layout = { 0, 0 };
 346
 347   /* The printf(3) format used for output.  */
 348   char const *format_str = NULL;
 349
 350   initialize_main (&argc, &argv);
 351   set_program_name (argv[0]);
 352   setlocale (LC_ALL, "");
 353   bindtextdomain (PACKAGE, LOCALEDIR);
 354   textdomain (PACKAGE);
 355
 356   atexit (close_stdout);
 357
 358   equal_width = false;
 359   separator = "\n";
 360
 361   /* We have to handle negative numbers in the command line but this
 362      conflicts with the command line arguments.  So explicitly check first
 363      whether the next argument looks like a negative number.  */
 364   while (optind < argc)
 365     {
 366       if (argv[optind][0] == '-'
 367           && ((optc = argv[optind][1]) == '.' || ISDIGIT (optc)))
 368         {
 369           /* means negative number */
 370           break;
 371         }
 372
 373       optc = getopt_long (argc, argv, "+f:s:w", long_options, NULL);
 374       if (optc == -1)
 375         break;
 376
 377       switch (optc)
 378         {
 379         case 'f':
 380           format_str = optarg;
 381           break;
 382
 383         case 's':
 384           separator = optarg;
 385           break;
 386
 387         case 'w':
 388           equal_width = true;
 389           break;
 390
 391         case_GETOPT_HELP_CHAR;
 392
 393         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 394
 395         default:
 396           usage (EXIT_FAILURE);
 397         }
 398     }
 399
 400   if (argc - optind < 1)
 401     {
 402       error (0, 0, _("missing operand"));
 403       usage (EXIT_FAILURE);
 404     }
 405
 406   if (3 < argc - optind)
 407     {
 408       error (0, 0, _("extra operand %s"), quote (argv[optind + 3]));
 409       usage (EXIT_FAILURE);
 410     }
 411
 412   if (format_str)
 413     format_str = long_double_format (format_str, &layout);
 414
 415   last = scan_arg (argv[optind++]);
 416
 417   if (optind < argc)
 418     {
 419       first = last;
 420       last = scan_arg (argv[optind++]);
 421
 422       if (optind < argc)
 423         {
 424           step = last;
 425           last = scan_arg (argv[optind++]);
 426         }
 427     }
 428
 429   if (format_str != NULL && equal_width)
 430     {
 431       error (0, 0, _("format string may not be specified"
 432                      " when printing equal width strings"));
 433       usage (EXIT_FAILURE);
 434     }
 435
 436   if (format_str == NULL)
 437     format_str = get_default_format (first, step, last);
 438
 439   print_numbers (format_str, layout, first.value, step.value, last.value);
 440
 441   exit (EXIT_SUCCESS);
 442 }