/*      $OpenBSD: getopt_long.c,v 1.26 2013/06/08 22:47:56 millert Exp $        */
/*      $NetBSD: getopt_long.c,v 1.15 2002/01/31 22:43:40 tv Exp $      */

/*
 * Copyright (c) 2002 Todd C. Miller <Todd.Miller@courtesan.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Sponsored in part by the Defense Advanced Research Projects
 * Agency (DARPA) and Air Force Research Laboratory, Air Force
 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
 */
/*-
 * Copyright (c) 2000 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Dieter Baron and Thomas Klausner.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

#include <sys/cdefs.h>

#include <errno.h>
#include <getopt.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define GNU_COMPATIBLE          /* Be more compatible, configure's use us! */

#if 1                           /* we prefer to keep our getopt(3) */
#define REPLACE_GETOPT          /* use this getopt as the system getopt(3) */
#endif

#ifdef REPLACE_GETOPT
int     opterr = 1;             /* if error message should be printed */
int     optind = 1;             /* index into parent argv vector */
int     optopt = '?';           /* character checked for validity */
int     optreset;               /* reset getopt */
char    *optarg;                /* argument associated with option */
#endif

#define PRINT_ERROR     ((opterr) && (*options != ':'))

#define FLAG_PERMUTE    0x01    /* permute non-options to the end of argv */
#define FLAG_ALLARGS    0x02    /* treat non-options as args to option "-1" */
#define FLAG_LONGONLY   0x04    /* operate as getopt_long_only */

/* return values */
#define BADCH           (int)'?'
#define BADARG          ((*options == ':') ? (int)':' : (int)'?')
#define INORDER         (int)1

static char EMSG[] = "";

#ifdef GNU_COMPATIBLE
#define NO_PREFIX       (-1)
#define D_PREFIX        0
#define DD_PREFIX       1
#define W_PREFIX        2
#endif

static int getopt_internal(int, char * const *, const char *,
                           const struct option *, int *, int);
static int parse_long_options(char * const *, const char *,
                              const struct option *, int *, int, int);
static int gcd(int, int);
static void permute_args(int, int, int, char * const *);

static char *place = EMSG; /* option letter processing */

/* XXX: set optreset to 1 rather than these two */
static int nonopt_start = -1; /* first non option argument (for permute) */
static int nonopt_end = -1;   /* first option after non options (for permute) */

/* Error messages */
static const char recargchar[] = "option requires an argument -- %c";
static const char illoptchar[] = "illegal option -- %c"; /* From P1003.2 */
#ifdef GNU_COMPATIBLE
static int dash_prefix = NO_PREFIX;
static const char gnuoptchar[] = "invalid option -- %c";

static const char recargstring[] = "option `%s%s' requires an argument";
static const char ambig[] = "option `%s%.*s' is ambiguous";
static const char noarg[] = "option `%s%.*s' doesn't allow an argument";
static const char illoptstring[] = "unrecognized option `%s%s'";
#else
static const char recargstring[] = "option requires an argument -- %s";
static const char ambig[] = "ambiguous option -- %.*s";
static const char noarg[] = "option doesn't take an argument -- %.*s";
static const char illoptstring[] = "unknown option -- %s";
#endif

/* XXX: work around lack of getprogname() */
static const char * prognamestring;

/* XXX: stolen from freebsd-src/lib/libc/gen/err.c */
static void
vwarnx(const char *fmt, va_list ap)
{
        int saved_errno = errno;
        FILE* err_file  = stderr;   /* XXX: simplified */

        fprintf(err_file, "%s: ", prognamestring);
        if (fmt != NULL)
                vfprintf(err_file, fmt, ap);
        fprintf(err_file, "\n");

        errno = saved_errno;
}

static void
warnx(const char* fmt, ...)
{
        va_list ap;
        va_start(ap, fmt);
        vwarnx(fmt, ap);
        va_end(ap);
}

/*
 * Compute the greatest common divisor of a and b.
 */
static int
gcd(int a, int b)
{
        int c;

        c = a % b;
        while (c != 0) {
                a = b;
                b = c;
                c = a % b;
        }

        return (b);
}

/*
 * Exchange the block from nonopt_start to nonopt_end with the block
 * from nonopt_end to opt_end (keeping the same order of arguments
 * in each block).
 */
static void
permute_args(int panonopt_start, int panonopt_end, int opt_end,
        char * const *nargv)
{
        int cstart, cyclelen, i, j, ncycle, nnonopts, nopts, pos;
        char *swap;

        /*
         * compute lengths of blocks and number and size of cycles
         */
        nnonopts = panonopt_end - panonopt_start;
        nopts = opt_end - panonopt_end;
        ncycle = gcd(nnonopts, nopts);
        cyclelen = (opt_end - panonopt_start) / ncycle;

        for (i = 0; i < ncycle; i++) {
                cstart = panonopt_end+i;
                pos = cstart;
                for (j = 0; j < cyclelen; j++) {
                        if (pos >= panonopt_end)
                                pos -= nnonopts;
                        else
                                pos += nopts;
                        swap = nargv[pos];
                        /* LINTED const cast */
                        ((char **) nargv)[pos] = nargv[cstart];
                        /* LINTED const cast */
                        ((char **)nargv)[cstart] = swap;
                }
        }
}

/*
 * parse_long_options --
 *      Parse long options in argc/argv argument vector.
 * Returns -1 if short_too is set and the option does not match long_options.
 */
static int
parse_long_options(char * const *nargv, const char *options,
        const struct option *long_options, int *idx, int short_too, int flags)
{
        char *current_argv, *has_equal;
#ifdef GNU_COMPATIBLE
        const char *current_dash;
#endif
        size_t current_argv_len;
        int i, match, exact_match, second_partial_match;

        current_argv = place;
#ifdef GNU_COMPATIBLE
        switch (dash_prefix) {
                case D_PREFIX:
                        current_dash = "-";
                        break;
                case DD_PREFIX:
                        current_dash = "--";
                        break;
                case W_PREFIX:
                        current_dash = "-W ";
                        break;
                default:
                        current_dash = "";
                        break;
        }
#endif
        match = -1;
        exact_match = 0;
        second_partial_match = 0;

        optind++;

        if ((has_equal = strchr(current_argv, '=')) != NULL) {
                /* argument found (--option=arg) */
                current_argv_len = has_equal - current_argv;
                has_equal++;
        } else
                current_argv_len = strlen(current_argv);

        for (i = 0; long_options[i].name; i++) {
                /* find matching long option */
                if (strncmp(current_argv, long_options[i].name,
                    current_argv_len))
                        continue;

                if (strlen(long_options[i].name) == current_argv_len) {
                        /* exact match */
                        match = i;
                        exact_match = 1;
                        break;
                }
                /*
                 * If this is a known short option, don't allow
                 * a partial match of a single character.
                 */
                if (short_too && current_argv_len == 1)
                        continue;

                if (match == -1)        /* first partial match */
                        match = i;
                else if ((flags & FLAG_LONGONLY) ||
                         long_options[i].has_arg !=
                             long_options[match].has_arg ||
                         long_options[i].flag != long_options[match].flag ||
                         long_options[i].val != long_options[match].val)
                        second_partial_match = 1;
        }
        if (!exact_match && second_partial_match) {
                /* ambiguous abbreviation */
                if (PRINT_ERROR)
                        warnx(ambig,
#ifdef GNU_COMPATIBLE
                             current_dash,
#endif
                             (int)current_argv_len,
                             current_argv);
                optopt = 0;
                return (BADCH);
        }
        if (match != -1) {              /* option found */
                if (long_options[match].has_arg == no_argument
                    && has_equal) {
                        if (PRINT_ERROR)
                                warnx(noarg,
#ifdef GNU_COMPATIBLE
                                     current_dash,
#endif
                                     (int)current_argv_len,
                                     current_argv);
                        /*
                         * XXX: GNU sets optopt to val regardless of flag
                         */
                        if (long_options[match].flag == NULL)
                                optopt = long_options[match].val;
                        else
                                optopt = 0;
#ifdef GNU_COMPATIBLE
                        return (BADCH);
#else
                        return (BADARG);
#endif
                }
                if (long_options[match].has_arg == required_argument ||
                    long_options[match].has_arg == optional_argument) {
                        if (has_equal)
                                optarg = has_equal;
                        else if (long_options[match].has_arg ==
                            required_argument) {
                                /*
                                 * optional argument doesn't use next nargv
                                 */
                                optarg = nargv[optind++];
                        }
                }
                if ((long_options[match].has_arg == required_argument)
                    && (optarg == NULL)) {
                        /*
                         * Missing argument; leading ':' indicates no error
                         * should be generated.
                         */
                        if (PRINT_ERROR)
                                warnx(recargstring,
#ifdef GNU_COMPATIBLE
                                    current_dash,
#endif
                                    current_argv);
                        /*
                         * XXX: GNU sets optopt to val regardless of flag
                         */
                        if (long_options[match].flag == NULL)
                                optopt = long_options[match].val;
                        else
                                optopt = 0;
                        --optind;
                        return (BADARG);
                }
        } else {                        /* unknown option */
                if (short_too) {
                        --optind;
                        return (-1);
                }
                if (PRINT_ERROR)
                        warnx(illoptstring,
#ifdef GNU_COMPATIBLE
                              current_dash,
#endif
                              current_argv);
                optopt = 0;
                return (BADCH);
        }
        if (idx)
                *idx = match;
        if (long_options[match].flag) {
                *long_options[match].flag = long_options[match].val;
                return (0);
        } else
                return (long_options[match].val);
}

/*
 * getopt_internal --
 *      Parse argc/argv argument vector.  Called by user level routines.
 */
static int
getopt_internal(int nargc, char * const *nargv, const char *options,
        const struct option *long_options, int *idx, int flags)
{
        char *oli;                              /* option letter list index */
        int optchar, short_too;
        static int posixly_correct = -1;

        if (options == NULL)
                return (-1);

        /*
         * XXX work around lack of getprogname()
         */
        prognamestring = nargv[0];

        /*
         * XXX Some GNU programs (like cvs) set optind to 0 instead of
         * XXX using optreset.  Work around this braindamage.
         */
        if (optind == 0)
                optind = optreset = 1;

        /*
         * Disable GNU extensions if POSIXLY_CORRECT is set or options
         * string begins with a '+'.
         */
        if (posixly_correct == -1 || optreset)
                posixly_correct = (getenv("POSIXLY_CORRECT") != NULL);
        if (*options == '-')
                flags |= FLAG_ALLARGS;
        else if (posixly_correct || *options == '+')
                flags &= ~FLAG_PERMUTE;
        if (*options == '+' || *options == '-')
                options++;

        optarg = NULL;
        if (optreset)
                nonopt_start = nonopt_end = -1;
start:
        if (optreset || !*place) {              /* update scanning pointer */
                optreset = 0;
                if (optind >= nargc) {          /* end of argument vector */
                        place = EMSG;
                        if (nonopt_end != -1) {
                                /* do permutation, if we have to */
                                permute_args(nonopt_start, nonopt_end,
                                    optind, nargv);
                                optind -= nonopt_end - nonopt_start;
                        }
                        else if (nonopt_start != -1) {
                                /*
                                 * If we skipped non-options, set optind
                                 * to the first of them.
                                 */
                                optind = nonopt_start;
                        }
                        nonopt_start = nonopt_end = -1;
                        return (-1);
                }
                if (*(place = nargv[optind]) != '-' ||
#ifdef GNU_COMPATIBLE
                    place[1] == '\0') {
#else
                    (place[1] == '\0' && strchr(options, '-') == NULL)) {
#endif
                        place = EMSG;           /* found non-option */
                        if (flags & FLAG_ALLARGS) {
                                /*
                                 * GNU extension:
                                 * return non-option as argument to option 1
                                 */
                                optarg = nargv[optind++];
                                return (INORDER);
                        }
                        if (!(flags & FLAG_PERMUTE)) {
                                /*
                                 * If no permutation wanted, stop parsing
                                 * at first non-option.
                                 */
                                return (-1);
                        }
                        /* do permutation */
                        if (nonopt_start == -1)
                                nonopt_start = optind;
                        else if (nonopt_end != -1) {
                                permute_args(nonopt_start, nonopt_end,
                                    optind, nargv);
                                nonopt_start = optind -
                                    (nonopt_end - nonopt_start);
                                nonopt_end = -1;
                        }
                        optind++;
                        /* process next argument */
                        goto start;
                }
                if (nonopt_start != -1 && nonopt_end == -1)
                        nonopt_end = optind;

                /*
                 * If we have "-" do nothing, if "--" we are done.
                 */
                if (place[1] != '\0' && *++place == '-' && place[1] == '\0') {
                        optind++;
                        place = EMSG;
                        /*
                         * We found an option (--), so if we skipped
                         * non-options, we have to permute.
                         */
                        if (nonopt_end != -1) {
                                permute_args(nonopt_start, nonopt_end,
                                    optind, nargv);
                                optind -= nonopt_end - nonopt_start;
                        }
                        nonopt_start = nonopt_end = -1;
                        return (-1);
                }
        }

        /*
         * Check long options if:
         *  1) we were passed some
         *  2) the arg is not just "-"
         *  3) either the arg starts with -- we are getopt_long_only()
         */
        if (long_options != NULL && place != nargv[optind] &&
            (*place == '-' || (flags & FLAG_LONGONLY))) {
                short_too = 0;
#ifdef GNU_COMPATIBLE
                dash_prefix = D_PREFIX;
#endif
                if (*place == '-') {
                        place++;                /* --foo long option */
                        if (*place == '\0')
                                return (BADARG);        /* malformed option */
#ifdef GNU_COMPATIBLE
                        dash_prefix = DD_PREFIX;
#endif
                } else if (*place != ':' && strchr(options, *place) != NULL)
                        short_too = 1;          /* could be short option too */

                optchar = parse_long_options(nargv, options, long_options,
                    idx, short_too, flags);
                if (optchar != -1) {
                        place = EMSG;
                        return (optchar);
                }
        }

        if ((optchar = (int)*place++) == (int)':' ||
            (optchar == (int)'-' && *place != '\0') ||
            (oli = strchr(options, optchar)) == NULL) {
                /*
                 * If the user specified "-" and  '-' isn't listed in
                 * options, return -1 (non-option) as per POSIX.
                 * Otherwise, it is an unknown option character (or ':').
                 */
                if (optchar == (int)'-' && *place == '\0')
                        return (-1);
                if (!*place)
                        ++optind;
#ifdef GNU_COMPATIBLE
                if (PRINT_ERROR)
                        warnx(posixly_correct ? illoptchar : gnuoptchar,
                              optchar);
#else
                if (PRINT_ERROR)
                        warnx(illoptchar, optchar);
#endif
                optopt = optchar;
                return (BADCH);
        }
        if (long_options != NULL && optchar == 'W' && oli[1] == ';') {
                /* -W long-option */
                if (*place)                     /* no space */
                        /* NOTHING */;
                else if (++optind >= nargc) {   /* no arg */
                        place = EMSG;
                        if (PRINT_ERROR)
                                warnx(recargchar, optchar);
                        optopt = optchar;
                        return (BADARG);
                } else                          /* white space */
                        place = nargv[optind];
#ifdef GNU_COMPATIBLE
                dash_prefix = W_PREFIX;
#endif
                optchar = parse_long_options(nargv, options, long_options,
                    idx, 0, flags);
                place = EMSG;
                return (optchar);
        }
        if (*++oli != ':') {                    /* doesn't take argument */
                if (!*place)
                        ++optind;
        } else {                                /* takes (optional) argument */
                optarg = NULL;
                if (*place)                     /* no white space */
                        optarg = place;
                else if (oli[1] != ':') {       /* arg not optional */
                        if (++optind >= nargc) {        /* no arg */
                                place = EMSG;
                                if (PRINT_ERROR)
                                        warnx(recargchar, optchar);
                                optopt = optchar;
                                return (BADARG);
                        } else
                                optarg = nargv[optind];
                }
                place = EMSG;
                ++optind;
        }
        /* dump back option letter */
        return (optchar);
}

#ifdef REPLACE_GETOPT
/*
 * getopt --
 *      Parse argc/argv argument vector.
 *
 * [eventually this will replace the BSD getopt]
 */
int
getopt(int nargc, char * const *nargv, const char *options)
{

        /*
         * We don't pass FLAG_PERMUTE to getopt_internal() since
         * the BSD getopt(3) (unlike GNU) has never done this.
         *
         * Furthermore, since many privileged programs call getopt()
         * before dropping privileges it makes sense to keep things
         * as simple (and bug-free) as possible.
         */
        return (getopt_internal(nargc, nargv, options, NULL, NULL, 0));
}
#endif /* REPLACE_GETOPT */

/*
 * getopt_long --
 *      Parse argc/argv argument vector.
 */
int
getopt_long(int nargc, char * const *nargv, const char *options,
        const struct option *long_options, int *idx)
{

        return (getopt_internal(nargc, nargv, options, long_options, idx,
            FLAG_PERMUTE));
}

/*
 * getopt_long_only --
 *      Parse argc/argv argument vector.
 */
int
getopt_long_only(int nargc, char * const *nargv, const char *options,
        const struct option *long_options, int *idx)
{

        return (getopt_internal(nargc, nargv, options, long_options, idx,
            FLAG_PERMUTE|FLAG_LONGONLY));
}

