getopt.c

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/*
 * getopt.c --
 *
 *      Standard UNIX getopt function.  Code is from BSD.
 *
 * Copyright (c) 1987-2002 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:
 *
 * A. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * B. 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.
 * C. Neither the names of the copyright holders 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 COPYRIGHT HOLDERS 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.
 */

/* #if !defined(lint)
 * static char sccsid[] = "@(#)getopt.c 8.2 (Berkeley) 4/2/94";
 * #endif
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* declarations to provide consistent linkage */
extern char *optarg;
extern int optind;
extern int opterr;

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

#define BADCH   (int)'?'
#define BADARG  (int)':'
#define EMSG    ""

/*
 * getopt --
 *      Parse argc/argv argument vector.
 */
int
getopt(nargc, nargv, ostr)
        int nargc;
        char * const *nargv;
        const char *ostr;
{
        static char *place = EMSG;              /* option letter processing */
        char *oli;                              /* option letter list index */

        if (optreset || !*place) {              /* update scanning pointer */
                optreset = 0;
                if (optind >= nargc || *(place = nargv[optind]) != '-') {
                        place = EMSG;
                        return (EOF);
                }
                if (place[1] && *++place == '-') {      /* found "--" */
                        ++optind;
                        place = EMSG;
                        return (EOF);
                }
        }                                       /* option letter okay? */
        if ((optopt = (int)*place++) == (int)':' ||
            !(oli = strchr(ostr, optopt))) {
                /*
                 * if the user didn't specify '-' as an option,
                 * assume it means EOF.
                 */
                if (optopt == (int)'-')
                        return (EOF);
                if (!*place)
                        ++optind;
                if (opterr && *ostr != ':')
                        (void)fprintf(stderr,
                            "%s: illegal option -- %c\n", __FILE__, optopt);
                return (BADCH);
        }
        if (*++oli != ':') {                    /* don't need argument */
                optarg = NULL;
                if (!*place)
                        ++optind;
        }
        else {                                  /* need an argument */
                if (*place)                     /* no white space */
                        optarg = place;
                else if (nargc <= ++optind) {   /* no arg */
                        place = EMSG;
                        if (*ostr == ':')
                                return (BADARG);
                        if (opterr)
                                (void)fprintf(stderr,
                                    "%s: option requires an argument -- %c\n",
                                    __FILE__, optopt);
                        return (BADCH);
                }
                else                            /* white space */
                        optarg = nargv[optind];
                place = EMSG;
                ++optind;
        }
        return (optopt);                        /* dump back option letter */
}