release/src/router/busybox/coreutils/seq.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * seq implementation for busybox
   4  *
   5  * Copyright (C) 2004, Glenn McGrath
   6  *
   7  * Licensed under GPLv2, see file LICENSE in this source tree.
   8  */
   9
  10 //usage:#define seq_trivial_usage
  11 //usage:       "[-w] [-s SEP] [FIRST [INC]] LAST"
  12 //usage:#define seq_full_usage "\n\n"
  13 //usage:       "Print numbers from FIRST to LAST, in steps of INC.\n"
  14 //usage:       "FIRST, INC default to 1.\n"
  15 //usage:     "\n        -w      Pad to last with leading zeros"
  16 //usage:     "\n        -s SEP  String separator"
  17
  18 #include "libbb.h"
  19
  20 /* This is a NOFORK applet. Be very careful! */
  21
  22 int seq_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  23 int seq_main(int argc, char **argv)
  24 {
  25         enum {
  26                 OPT_w = (1 << 0),
  27                 OPT_s = (1 << 1),
  28         };
  29         double first, last, increment, v;
  30         unsigned n;
  31         unsigned width;
  32         unsigned frac_part;
  33         const char *sep, *opt_s = "\n";
  34         unsigned opt;
  35
  36 #if ENABLE_LOCALE_SUPPORT
  37         /* Undo busybox.c: on input, we want to use dot
  38          * as fractional separator, regardless of current locale */
  39         setlocale(LC_NUMERIC, "C");
  40 #endif
  41
  42         opt = getopt32(argv, "+ws:", &opt_s);
  43         argc -= optind;
  44         argv += optind;
  45         first = increment = 1;
  46         errno = 0;
  47         switch (argc) {
  48                         char *pp;
  49                 case 3:
  50                         increment = strtod(argv[1], &pp);
  51                         errno |= *pp;
  52                 case 2:
  53                         first = strtod(argv[0], &pp);
  54                         errno |= *pp;
  55                 case 1:
  56                         last = strtod(argv[argc-1], &pp);
  57                         if (!errno && *pp == '\0')
  58                                 break;
  59                 default:
  60                         bb_show_usage();
  61         }
  62
  63 #if ENABLE_LOCALE_SUPPORT
  64         setlocale(LC_NUMERIC, "");
  65 #endif
  66
  67         /* Last checked to be compatible with: coreutils-6.10 */
  68         width = 0;
  69         frac_part = 0;
  70         while (1) {
  71                 char *dot = strchrnul(*argv, '.');
  72                 int w = (dot - *argv);
  73                 int f = strlen(dot);
  74                 if (width < w)
  75                         width = w;
  76                 argv++;
  77                 if (!*argv)
  78                         break;
  79                 /* Why do the above _before_ frac check below?
  80                  * Try "seq 1 2.0" and "seq 1.0 2.0":
  81                  * coreutils never pay attention to the number
  82                  * of fractional digits in last arg. */
  83                 if (frac_part < f)
  84                         frac_part = f;
  85         }
  86         if (frac_part) {
  87                 frac_part--;
  88                 if (frac_part)
  89                         width += frac_part + 1;
  90         }
  91         if (!(opt & OPT_w))
  92                 width = 0;
  93
  94         sep = "";
  95         v = first;
  96         n = 0;
  97         while (increment >= 0 ? v <= last : v >= last) {
  98                 if (printf("%s%0*.*f", sep, width, frac_part, v) < 0)
  99                         break; /* I/O error, bail out (yes, this really happens) */
 100                 sep = opt_s;
 101                 /* v += increment; - would accumulate floating point errors */
 102                 n++;
 103                 v = first + n * increment;
 104         }
 105         if (n) /* if while loop executed at least once */
 106                 bb_putchar('\n');
 107
 108         return fflush_all();
 109 }