LXR 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//config:config SEQ
  10//config:       bool "seq (3.8 kb)"
  11//config:       default y
  12//config:       help
  13//config:       print a sequence of numbers
  14
  15//applet:IF_SEQ(APPLET_NOEXEC(seq, seq, BB_DIR_USR_BIN, BB_SUID_DROP, seq))
  16/* was NOFORK, but then "seq 1 999999999" can't be ^C'ed if run by hush */
  17
  18//kbuild:lib-$(CONFIG_SEQ) += seq.o
  19
  20//usage:#define seq_trivial_usage
  21//usage:       "[-w] [-s SEP] [FIRST [INC]] LAST"
  22//usage:#define seq_full_usage "\n\n"
  23//usage:       "Print numbers from FIRST to LAST, in steps of INC.\n"
  24//usage:       "FIRST, INC default to 1.\n"
  25//usage:     "\n        -w      Pad to last with leading zeros"
  26//usage:     "\n        -s SEP  String separator"
  27
  28#include "libbb.h"
  29
  30/* This is a NOEXEC applet. Be very careful! */
  31
  32int seq_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  33int seq_main(int argc, char **argv)
  34{
  35        enum {
  36                OPT_w = (1 << 0),
  37                OPT_s = (1 << 1),
  38        };
  39        double first, last, increment, v;
  40        unsigned n;
  41        unsigned width;
  42        unsigned frac_part;
  43        const char *sep, *opt_s = "\n";
  44        unsigned opt;
  45
  46#if ENABLE_LOCALE_SUPPORT
  47        /* Undo busybox.c: on input, we want to use dot
  48         * as fractional separator, regardless of current locale */
  49        setlocale(LC_NUMERIC, "C");
  50#endif
  51
  52        opt = getopt32(argv, "+ws:", &opt_s);
  53        argc -= optind;
  54        argv += optind;
  55        first = increment = 1;
  56        errno = 0;
  57        switch (argc) {
  58                        char *pp;
  59                case 3:
  60                        increment = strtod(argv[1], &pp);
  61                        errno |= *pp;
  62                case 2:
  63                        first = strtod(argv[0], &pp);
  64                        errno |= *pp;
  65                case 1:
  66                        last = strtod(argv[argc-1], &pp);
  67                        if (!errno && *pp == '\0')
  68                                break;
  69                default:
  70                        bb_show_usage();
  71        }
  72
  73#if ENABLE_LOCALE_SUPPORT
  74        setlocale(LC_NUMERIC, "");
  75#endif
  76
  77        /* Last checked to be compatible with: coreutils-6.10 */
  78        width = 0;
  79        frac_part = 0;
  80        while (1) {
  81                char *dot = strchrnul(*argv, '.');
  82                int w = (dot - *argv);
  83                int f = strlen(dot);
  84                if (width < w)
  85                        width = w;
  86                argv++;
  87                if (!*argv)
  88                        break;
  89                /* Why do the above _before_ frac check below?
  90                 * Try "seq 1 2.0" and "seq 1.0 2.0":
  91                 * coreutils never pay attention to the number
  92                 * of fractional digits in last arg. */
  93                if (frac_part < f)
  94                        frac_part = f;
  95        }
  96        if (frac_part) {
  97                frac_part--;
  98                if (frac_part)
  99                        width += frac_part + 1;
 100        }
 101        if (!(opt & OPT_w))
 102                width = 0;
 103
 104        sep = "";
 105        v = first;
 106        n = 0;
 107        while (increment >= 0 ? v <= last : v >= last) {
 108                if (printf("%s%0*.*f", sep, width, frac_part, v) < 0)
 109                        break; /* I/O error, bail out (yes, this really happens) */
 110                sep = opt_s;
 111                /* v += increment; - would accumulate floating point errors */
 112                n++;
 113                v = first + n * increment;
 114        }
 115        if (n) /* if while loop executed at least once */
 116                bb_putchar('\n');
 117
 118        return fflush_all();
 119}
 120