/*      $OpenBSD: jot.c,v 1.56 2021/08/13 12:37:28 jmc Exp $    */
/*      $NetBSD: jot.c,v 1.3 1994/12/02 20:29:43 pk Exp $       */

/*-
 * Copyright (c) 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * jot - print sequential or random data
 *
 * Author:  John Kunze, Office of Comp. Affairs, UCB
 */

#include <ctype.h>
#include <err.h>
#include <limits.h>
#include <math.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define REPS    1
#define BEGIN   2
#define ENDER   4
#define STEP    8

#define is_default(s)   (strcmp((s), "-") == 0)

static long     reps    = 100;
static double   begin   = 1;
static double   ender   = 100;
static double   step    = 1;

static char     *format = "";
static char     *sepstring = "\n";
static int      prec = -1;
static bool     boring;
static bool     chardata;
static bool     finalnl = true;
static bool     infinity;
static bool     intdata;
static bool     longdata;
static bool     nosign;
static bool     randomize;
static bool     word;

static void     getformat(void);
static int      getprec(char *);
static int      putdata(double, bool);
static void __dead      usage(void);

int
main(int argc, char *argv[])
{
        double          x;
        double          y;
        long            i;
        unsigned int    mask = 0;
        int             n = 0;
        int             ch;
        const char      *errstr;

        if (pledge("stdio", NULL) == -1)
                err(1, "pledge");

        while ((ch = getopt(argc, argv, "b:cnp:rs:w:")) != -1) {
                switch (ch) {
                case 'b':
                        boring = true;
                        chardata = word = false;
                        format = optarg;
                        break;
                case 'c':
                        chardata = true;
                        boring = word = false;
                        format = "";
                        break;
                case 'n':
                        finalnl = false;
                        break;
                case 'p':
                        prec = strtonum(optarg, 0, INT_MAX, &errstr);
                        if (errstr != NULL)
                                errx(1, "bad precision value, %s: %s", errstr,
                                        optarg);
                        break;
                case 'r':
                        randomize = true;
                        break;
                case 's':
                        sepstring = optarg;
                        break;
                case 'w':
                        word = true;
                        boring = chardata = false;
                        format = optarg;
                        break;
                default:
                        usage();
                }
        }
        argc -= optind;
        argv += optind;

        switch (argc) { /* examine args right to left, falling thru cases */
        case 4:
                if (!is_default(argv[3])) {
                        if (!sscanf(argv[3], "%lf", &step))
                                errx(1, "Bad s value: %s", argv[3]);
                        mask |= STEP;
                        if (randomize)
                                warnx("random seeding not supported");
                }
        case 3:
                if (!is_default(argv[2])) {
                        if (!sscanf(argv[2], "%lf", &ender))
                                ender = argv[2][strlen(argv[2])-1];
                        mask |= ENDER;
                        if (prec == -1)
                                n = getprec(argv[2]);
                }
        case 2:
                if (!is_default(argv[1])) {
                        if (!sscanf(argv[1], "%lf", &begin))
                                begin = argv[1][strlen(argv[1])-1];
                        mask |= BEGIN;
                        if (prec == -1)
                                prec = getprec(argv[1]);
                        if (n > prec)           /* maximum precision */
                                prec = n;
                }
        case 1:
                if (!is_default(argv[0])) {
                        reps = strtonum(argv[0], 0, LONG_MAX, &errstr);
                        if (errstr != NULL)
                                errx(1, "Bad reps value, %s: %s", errstr,
                                    argv[0]);
                        mask |= REPS;
                        if (reps == 0)
                                infinity = true;
                }
        case 0:
                if (prec == -1)
                        prec = 0;
                break;
        default:
                errx(1, "Too many arguments.  What do you mean by %s?",
                    argv[4]);
        }

        if (!boring)
                getformat();

        if (!randomize) {
                /*
                 * Consolidate the values of reps, begin, ender, step:
                 * The formula ender - begin == (reps - 1) * step shows that any
                 * three determine the fourth (unless reps == 1 or step == 0).
                 * The manual states the following rules:
                 * 1. If four are specified, compare the given and the computed
                 *    value of reps and take the smaller of the two.
                 * 2. If steps was omitted, it takes the default, unless both
                 *    begin and ender were specified.
                 * 3. Assign defaults to omitted values for reps, begin, ender,
                 *    from left to right.
                 */
                switch (mask) { /* Four cases involve both begin and ender. */
                case REPS | BEGIN | ENDER | STEP:
                        if (infinity)
                                errx(1,
                                    "Can't specify end of infinite sequence");
                        if (step != 0.0) {
                                long t = (ender - begin + step) / step;
                                if (t <= 0)
                                        errx(1, "Impossible stepsize");
                                if (t < reps)
                                        reps = t;
                        }
                        break;
                case REPS | BEGIN | ENDER:
                        if (infinity)
                                errx(1,
                                    "Can't specify end of infinite sequence");
                        if (reps == 1)
                                step = 0.0;
                        else
                                step = (ender - begin) / (reps - 1);
                        break;
                case BEGIN | ENDER:
                        step = ender > begin ? 1 : -1; /* FreeBSD's behavior. */
                        /* FALLTHROUGH */
                case BEGIN | ENDER | STEP:
                        if (step == 0.0) {
                                reps = 0;
                                infinity = true;
                                break;
                        }
                        reps = (ender - begin + step) / step;
                        if (reps <= 0)
                                errx(1, "Impossible stepsize");
                        break;
                case ENDER:             /* Four cases involve only ender. */
                case ENDER | STEP:
                case REPS | ENDER:
                case REPS | ENDER | STEP:
                        if (infinity)
                                errx(1,
                                    "Must specify start of infinite sequence");
                        begin = ender - reps * step + step;
                        break;
                default:
                        /*
                         * The remaining eight cases omit ender.  We don't need
                         * to compute anything because only reps, begin, step
                         * are used for producing output below.  Rules 2. and 3.
                         * together imply that ender will be set last.
                         */
                        break;
                }

                for (i = 1, x = begin; i <= reps || infinity; i++, x += step)
                        if (putdata(x, reps == i && !infinity))
                                errx(1, "range error in conversion: %f", x);
        } else { /* Random output: use defaults for omitted values. */
                bool            use_unif = 0;
                uint32_t        pow10 = 1;
                uint32_t        uintx = 0; /* Initialized to make gcc happy. */

                if (prec > 9)   /* pow(10, prec) > UINT32_MAX */
                        errx(1, "requested precision too large");

                if (ender < begin) {
                        x = begin;
                        begin = ender;
                        ender = x;
                }
                x = ender - begin;

                if (prec > 0 || (fmod(ender, 1) == 0 && fmod(begin, 1) == 0)) {
                        double range;

                        while (prec-- > 0)
                                pow10 *= 10;

                        range = pow10 * (ender - begin);

                        /* If range is an integer, use arc4random_uniform(). */
                        if (fmod(range, 1) == 0) {
                                if (range >= UINT32_MAX)
                                        errx(1, "requested range too large");
                                use_unif = 1;
                                uintx = range + 1;
                        }
                }

                for (i = 1; i <= reps || infinity; i++) {
                        double v;

                        if (use_unif) {
                                y = arc4random_uniform(uintx) / (double)pow10;
                                v = y + begin;
                        } else {
                                y = arc4random() / ((double)0xffffffff + 1);
                                v = y * x + begin;
                        }
                        if (putdata(v, reps == i && !infinity))
                                errx(1, "range error in conversion: %f", v);
                }
        }

        if (finalnl)
                putchar('\n');

        return 0;
}

static int
putdata(double x, bool last)
{
        if (boring)
                printf("%s", format);
        else if (longdata && nosign) {
                if (x < 0.0 || x > (double)ULONG_MAX)
                        return 1;
                printf(format, (unsigned long)x);
        } else if (longdata) {
                if (x < (double)LONG_MIN || x > (double)LONG_MAX)
                        return 1;
                printf(format, (long)x);
        } else if (chardata || (intdata && !nosign)) {
                if (x < (double)INT_MIN || x > (double)INT_MAX)
                        return 1;
                printf(format, (int)x);
        } else if (intdata) {
                if (x < 0.0 || x > (double)UINT_MAX)
                        return 1;
                printf(format, (unsigned int)x);
        } else
                printf(format, x);
        if (!last)
                fputs(sepstring, stdout);

        return 0;
}

static void __dead
usage(void)
{
        (void)fprintf(stderr, "usage: jot [-cnr] [-b word] [-p precision] "
            "[-s string] [-w word]\n"
            "      [reps [begin [end [step]]]]\n");
        exit(1);
}

static int
getprec(char *s)
{
        if ((s = strchr(s, '.')) == NULL)
                return 0;
        return strspn(s + 1, "0123456789");
}

static void
getformat(void)
{
        char    *p;

        p = format;
        while ((p = strchr(p, '%')) != NULL && p[1] == '%')
                p += 2;

        if (p == NULL && !chardata) {
                if (asprintf(&format, "%s%%.%df", format, prec) == -1)
                        err(1, NULL);
        } else if (p == NULL && chardata) {
                if (asprintf(&format, "%s%%c", format) == -1)
                        err(1, NULL);
        } else if (p[1] == '\0') {
                /* cannot end in single '%' */
                if (asprintf(&format, "%s%%", format) == -1)
                        err(1, NULL);
        } else {
                /*
                 * Allow conversion format specifiers of the form
                 * %[#][ ][{+,-}][0-9]*[.[0-9]*]? where ? must be one of
                 * [l]{d,i,o,u,x} or {f,e,g,F,E,G,d,o,x,D,O,U,X,c,u}
                 */
                char    *fmt;
                int     dot, hash, space, sign, numbers;

                fmt = p++;
                dot = hash = space = sign = numbers = 0;
                while (!isalpha((unsigned char)*p)) {
                        if (isdigit((unsigned char)*p)) {
                                numbers++;
                                p++;
                        } else if ((*p == '#' && !(numbers|dot|sign|space|
                            hash++)) ||
                            (*p == ' ' && !(numbers|dot|space++)) ||
                            ((*p == '+' || *p == '-') && !(numbers|dot|sign++))
                            || (*p == '.' && !(dot++)))
                                p++;
                        else
                                goto fmt_broken;
                }
                if (*p == 'l') {
                        longdata = true;
                        if (*++p == 'l') {
                                p++;
                                goto fmt_broken;
                        }
                }
                switch (*p) {
                case 'd':
                case 'i':
                        intdata = true;
                        break;
                case 'o':
                case 'u':
                case 'x':
                case 'X':
                        intdata = nosign = true;
                        break;
                case 'D':
                        if (longdata)
                                goto fmt_broken;
                        longdata = intdata = true; /* same as %ld */
                        break;
                case 'O':
                case 'U':
                        if (longdata)
                                goto fmt_broken;
                        longdata = intdata = nosign = true; /* same as %l[ou] */
                        break;
                case 'c':
                        if (longdata)
                                goto fmt_broken;
                        chardata = true;
                        break;
                case 'e':
                case 'E':
                case 'f':
                case 'F':
                case 'g':
                case 'G':
                        if (longdata)
                                goto fmt_broken;
                        /* No cast needed for printing in putdata() */
                        break;
                default:
fmt_broken:
                        errx(1, "illegal or unsupported format '%.*s'",
                            (int)(p + 1 - fmt), fmt);
                }

                while ((p = strchr(p, '%')) != NULL && p[1] == '%')
                        p += 2;

                if (p != NULL) {
                        if (p[1] != '\0')
                                errx(1, "too many conversions");
                        /* cannot end in single '%' */
                        if (asprintf(&format, "%s%%", format) == -1)
                                err(1, NULL);
                }
        }
}