source: MondoRescue/branches/3.2/mindi-busybox/coreutils/seq.c@ 3232

/* vi: set sw=4 ts=4: */
/*
 * seq implementation for busybox
 *
 * Copyright (C) 2004, Glenn McGrath
 *
 * Licensed under GPLv2, see file LICENSE in this source tree.
 */

//usage:#define seq_trivial_usage
//usage:       "[-w] [-s SEP] [FIRST [INC]] LAST"
//usage:#define seq_full_usage "\n\n"
//usage:       "Print numbers from FIRST to LAST, in steps of INC.\n"
//usage:       "FIRST, INC default to 1.\n"
//usage:     "\n    -w  Pad to last with leading zeros"
//usage:     "\n    -s SEP  String separator"

#include "libbb.h"

/* This is a NOFORK applet. Be very careful! */

int seq_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int seq_main(int argc, char **argv)
{
    enum {
        OPT_w = (1 << 0),
        OPT_s = (1 << 1),
    };
    double first, last, increment, v;
    unsigned n;
    unsigned width;
    unsigned frac_part;
    const char *sep, *opt_s = "\n";
    unsigned opt;

#if ENABLE_LOCALE_SUPPORT
    /* Undo busybox.c: on input, we want to use dot
     * as fractional separator, regardless of current locale */
    setlocale(LC_NUMERIC, "C");
#endif

    opt = getopt32(argv, "+ws:", &opt_s);
    argc -= optind;
    argv += optind;
    first = increment = 1;
    errno = 0;
    switch (argc) {
            char *pp;
        case 3:
            increment = strtod(argv[1], &pp);
            errno |= *pp;
        case 2:
            first = strtod(argv[0], &pp);
            errno |= *pp;
        case 1:
            last = strtod(argv[argc-1], &pp);
            if (!errno && *pp == '\0')
                break;
        default:
            bb_show_usage();
    }

#if ENABLE_LOCALE_SUPPORT
    setlocale(LC_NUMERIC, "");
#endif

    /* Last checked to be compatible with: coreutils-6.10 */
    width = 0;
    frac_part = 0;
    while (1) {
        char *dot = strchrnul(*argv, '.');
        int w = (dot - *argv);
        int f = strlen(dot);
        if (width < w)
            width = w;
        argv++;
        if (!*argv)
            break;
        /* Why do the above _before_ frac check below?
         * Try "seq 1 2.0" and "seq 1.0 2.0":
         * coreutils never pay attention to the number
         * of fractional digits in last arg. */
        if (frac_part < f)
            frac_part = f;
    }
    if (frac_part) {
        frac_part--;
        if (frac_part)
            width += frac_part + 1;
    }
    if (!(opt & OPT_w))
        width = 0;

    sep = "";
    v = first;
    n = 0;
    while (increment >= 0 ? v <= last : v >= last) {
        if (printf("%s%0*.*f", sep, width, frac_part, v) < 0)
            break; /* I/O error, bail out (yes, this really happens) */
        sep = opt_s;
        /* v += increment; - would accumulate floating point errors */
        n++;
        v = first + n * increment;
    }
    if (n) /* if while loop executed at least once */
        bb_putchar('\n');

    return fflush_all();
}