getopt_long.c

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/*
 * getopt_long() -- long options parser
 *
 * Portions Copyright (c) 1987, 1993, 1994
 * The Regents of the University of California.  All rights reserved.
 *
 * Portions Copyright (c) 2003
 * PostgreSQL Global Development Group
 *
 * 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.
 *
 * src/port/getopt_long.c
 */
 
#include "c.h"
 
#include "getopt_long.h"
 
#define BADCH   '?'
#define BADARG  ':'
#define EMSG    ""
 
 
/*
 * getopt_long
 *  Parse argc/argv argument vector, with long options.
 *
 * This implementation does not use optreset.  Instead, we guarantee that
 * it can be restarted on a new argv array after a previous call returned -1,
 * if the caller resets optind to 1 before the first call of the new series.
 * (Internally, this means we must be sure to reset "place" to EMSG,
 * "nonopt_start" to -1, and "force_nonopt" to false before returning -1.)
 *
 * Note that this routine reorders the pointers in argv (despite the const
 * qualifier) so that all non-options will be at the end when -1 is returned.
 */
int
getopt_long(int argc, char *const argv[],
            const char *optstring,
            const struct option *longopts, int *longindex)
{
    static char *place = EMSG;  /* option letter processing */
    char       *oli;            /* option letter list index */
    static int  nonopt_start = -1;
    static bool force_nonopt = false;
 
    if (!*place)
    {                           /* update scanning pointer */
        char      **args = (char **) argv;
 
retry:
 
        /*
         * If we are out of arguments or only non-options remain, return -1.
         */
        if (optind >= argc || optind == nonopt_start)
        {
            place = EMSG;
            nonopt_start = -1;
            force_nonopt = false;
            return -1;
        }
 
        place = argv[optind];
 
        /*
         * An argument is a non-option if it meets any of the following
         * criteria: it follows an argument that is equivalent to the string
         * "--", it does not start with '-', or it is equivalent to the string
         * "-".  When we encounter a non-option, we move it to the end of argv
         * (after shifting all remaining arguments over to make room), and
         * then we try again with the next argument.
         */
        if (force_nonopt || place[0] != '-' || place[1] == '\0')
        {
            for (int i = optind; i < argc - 1; i++)
                args[i] = args[i + 1];
            args[argc - 1] = place;
 
            if (nonopt_start == -1)
                nonopt_start = argc - 1;
            else
                nonopt_start--;
 
            goto retry;
        }
 
        place++;
 
        if (place[0] == '-' && place[1] == '\0')
        {
            /* found "--", treat it as end of options */
            ++optind;
            force_nonopt = true;
            goto retry;
        }
 
        if (place[0] == '-' && place[1])
        {
            /* long option */
            size_t      namelen;
            int         i;
 
            place++;
 
            namelen = strcspn(place, "=");
            for (i = 0; longopts[i].name != NULL; i++)
            {
                if (strlen(longopts[i].name) == namelen
                    && strncmp(place, longopts[i].name, namelen) == 0)
                {
                    int         has_arg = longopts[i].has_arg;
 
                    if (has_arg != no_argument)
                    {
                        if (place[namelen] == '=')
                            optarg = place + namelen + 1;
                        else if (optind < argc - 1 &&
                                 has_arg == required_argument)
                        {
                            optind++;
                            optarg = argv[optind];
                        }
                        else
                        {
                            if (optstring[0] == ':')
                                return BADARG;
 
                            if (opterr && has_arg == required_argument)
                                fprintf(stderr,
                                        "%s: option requires an argument -- %s\n",
                                        argv[0], place);
 
                            place = EMSG;
                            optind++;
 
                            if (has_arg == required_argument)
                                return BADCH;
                            optarg = NULL;
                        }
                    }
                    else
                    {
                        optarg = NULL;
                        if (place[namelen] != 0)
                        {
                            /* XXX error? */
                        }
                    }
 
                    optind++;
 
                    if (longindex)
                        *longindex = i;
 
                    place = EMSG;
 
                    if (longopts[i].flag == NULL)
                        return longopts[i].val;
                    else
                    {
                        *longopts[i].flag = longopts[i].val;
                        return 0;
                    }
                }
            }
 
            if (opterr && optstring[0] != ':')
                fprintf(stderr,
                        "%s: illegal option -- %s\n", argv[0], place);
            place = EMSG;
            optind++;
            return BADCH;
        }
    }
 
    /* short option */
    optopt = (int) *place++;
 
    oli = strchr(optstring, optopt);
    if (!oli)
    {
        if (!*place)
            ++optind;
        if (opterr && *optstring != ':')
            fprintf(stderr,
                    "%s: illegal option -- %c\n", argv[0], optopt);
        return BADCH;
    }
 
    if (oli[1] != ':')
    {                           /* don't need argument */
        optarg = NULL;
        if (!*place)
            ++optind;
    }
    else
    {                           /* need an argument */
        if (*place)             /* no white space */
            optarg = place;
        else if (argc <= ++optind)
        {                       /* no arg */
            place = EMSG;
            if (*optstring == ':')
                return BADARG;
            if (opterr)
                fprintf(stderr,
                        "%s: option requires an argument -- %c\n",
                        argv[0], optopt);
            return BADCH;
        }
        else
            /* white space */
            optarg = argv[optind];
        place = EMSG;
        ++optind;
    }
    return optopt;
}