/*
 *      Copyright (c) 1984, 1985 AT&T
 *      All Rights Reserved
 *
 *      -- Note on Pg 127 of Proficient C, Augie Hanson, Microsoft Press --
 *      getopt() is reproduced with permission of the AT&T UNIX(R) System
 *      Toolchest.  This is a public domain version of getopt(3) that is
 *      distributed to registered Toolchest participants.
 *      Defining DOS_MODS alters the code slightly to obtain compatibility
 *      with DOS and support libraries provided with most DOS C compilers.
 */

#define DOS_MODS

#ifdef DOS_MODS
#define write _write
#endif

/* #ident "@(#)getopt.c   1.9" */

/*     3.0 SID #       1.2"    */
/*LINTLIBRARY*/

#define NULL    0
#define EOF     (-1)

/*
 *      For this to work under versions of DOS prior to 3.00, argv[0]
 *      must be set in main() to point to a valid program name or a
 *      reasonable substitute string.  (ARH 10-8-86)
 */
#define ERR(s, c)      if (opterr){\
        char errbuf[3];\
        errbuf[0] = c; errbuf[1] = '\r'; errbuf[2]='\n'; \
        (void) write(2, argv[0], (unsigned)strlen(argv[0]));\
        (void) write(2, s, (unsigned)strlen(s));\
        (void) write(2, errbuf, 3);}

#if defined (DOS_MODS)
/* permit function prototyping under DOS */
#include <stdlib.h>
#include <string.h>
#else
/* standard UNIX declarations */
extern int strcpy();
extern char *strchr();
/*
 *      The following line was moved here from the ERR definition
 *      to prevent a "duplicate definition" error message when the
 *      code is compiled under DOS.  (ARH, 10-8-86)
 */
 extern int strlen(), write();
 #endif

int    opterr = 1;
int    optind = 1;
int    optopt;
char   *optarg;

int getopt(argc, argv, opts)
int argc;
char **argv, *opts;
{
    static int sp = 1;
    register int c;
    register char *cp;

    if (sp == 1)
        if (optind >= argc ||
            argv[optind][0] != '-' || argv[optind][1] == '\0')
                return(EOF);
        else if (strcmp(argv[optind], "--") == NULL) {
            optind++;
            return(EOF);
        }
    optopt = c = argv[optind][sp];
    if (c == ':' || (cp = strchr(opts, c)) == NULL) {
        ERR(": illegal option -- ", c);
        if (argv[optind][++sp] == '\0') {
            optind++;
            sp = 1;
        }
        return('?');
    }
    if (*++cp == ':') {
        if (argv[optind][sp+1] != '\0')
            optarg = &argv[optind++][sp+1];
        else if (++optind >= argc) {
            ERR(": option requires an argument -- ", c);
            sp = 1;
            return('?');
        } else
            optarg = argv[optind++];
        sp = 1;
    } else {
        if (argv[optind][++sp] == '\0') {
            sp = 1;
            optind++;
        }
        optarg = NULL;
   }
   return(c);
}