usr/src/lib/libc/stdlib/getopt.c

/*
 * Copyright (c) 1987 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)getopt.c    4.11 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

#include <stdio.h>

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

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

getopt(nargc, nargv, ostr)
        int nargc;
        char **nargv, *ostr;
{
        static char *place = EMSG;              /* option letter processing */
        register char *oli;                     /* option letter list index */
        char *p, *index(), *rindex();

        if (!*place) {                          /* update scanning pointer */
                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 = index(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) {
                        if (!(p = rindex(*nargv, '/')))
                                p = *nargv;
                        else
                                ++p;
                        (void)fprintf(stderr, "%s: illegal option -- %c\n",
                            p, 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 (!(p = rindex(*nargv, '/')))
                                p = *nargv;
                        else
                                ++p;
                        if (opterr)
                                (void)fprintf(stderr,
                                    "%s: option requires an argument -- %c\n",
                                    p, optopt);
                        return(BADCH);
                }
                else                            /* white space */
                        optarg = nargv[optind];
                place = EMSG;
                ++optind;
        }
        return(optopt);                         /* dump back option letter */
}